DIAGNOSTIC PATHOLOGY AND MICROBIOLOGY AT A GLANCE

2008-01-10T23:58:00.001-08:00

Complete Blood Count(CBC)
Also known as: CBC, Hemogram, CBC with differentialRelated tests: Blood smear, Hemoglobin(MCH,MCHC), Hematocrit, Red blood cell (RBC) count, MCV,White blood cell (WBC) count, White blood cell to differential count, Platelet count

CBC helps to be precise, specific and comprehensive for differential diagnosis

It includes following tests:

1. Hemoglobin (Hb)
Normal Range (g/dL)
Males Females Newborn 3 months
13.5-18 12.5-16 15-24
>Increased in
Chronic hypoxia of bone marrow due to exercise of any cardio respiratory disorder: polycythemia Vera, Physiological in newborns and in adults at high altitude
All pathological causes of anemia, physiological in infants after 3 months of life (as infant is totally on milk feed, devoid of iron)

2. Total Erythrocyte count (RBC Count)
Normal Range (x 106/ cu.mm.)
Adult Males Adult Females Newborn
4.7-6 4.2-5.4 4.1-6.7
Increased and Decreased in (same as for Hb)

3.Mean Corpuscular Volume (MCV)
Normal Range
Adults-78-100 fL. Neonates - 102-115 fl.
Indications
Classification and differential diagnosis of anaemia:
>Increased in (MCV>95fL, Often >110fL)
Anaemias (megaloblastic anemias, Vit, B folate deficiency macrocytic anemia of pregnancy, megaloblastic anaemia of infancy) Infants and new borns.

Usually (eg iron deficeincy, thalassemia. lead poisining chronic disease, abnormal Hb.

4.Mean corpuscular Hemoglobin MCH
Introduction MCH is calculated as Hb divided by total RBC count
Normal range
27-31 pg.
Indications
Limited value in differntial diagnosis of anaemias. Used for instrument calibration

>Increased in
Macrocytic anaemia, Infants and newborns. Marked leukocytosis 1.50.000/cumm). cold agglutinins. in vivo hemolysis. Monoclonal proteins in blood. high heparin concetration. Lipemia
Microcytic and normocytic anaemias

5.Mean Corpuscular Hemoglobin Concentration MCHC
Introduction
MCHC is calculated as Hb divided by HCT
Normal Range
32-38%
Indications
For laboratory quality control. chiefly because changes occur very late in the course of iron deficiency when anemia is severe and for instument calibration
>Increased in
herediatary spherocytosis . Infants and newborns. other causes due to automated cell counters are hemolysis cold agglutinins, lipemia. Rouleaux or RBC agglutinates
Hypochronic anaemia Low MCHC may not occur in iron deficeincy aneamia when measured with automated instruments. Marked leukocytosis (automated cell counter)

Total Leukocyte Count TLC
Normal Range (leukocytes/cu.mm.)
Adults 4000-10,500
Newborn 9000-34,000
1-23 months 6000-14,000

Leukocytosis in
Any acute/Chronic pyogenic or pyrogenic (fever producing infection, leukemias, physiological in newborns, after exercise, in evenings, epinepherene injection stress, pregnancy, menstruation, lactation adminstration of steriods.
Leukopenia in
Some bacterial infections (eg. typhoid), viral or protozoal infection, bone marrow depression and starvation and physiological at night.

7.Differential Leukocyte Count DLC
Normal Range
Granulocytes Percentage Agranulocytes Percentage
Neutrophils 50-70% Lymphocytes 20-40%
Eosinophils 1-4% Monocytes 2-8%
Basophils <1%

Indications
Support diagnosis of various infections and inflammation: Diagnosis of myeloproliferative disorder: Neutrophils counts may be useful in acute appendicitis and neonatal sepsis with moderate sensitivity and specificity.

Causes of neutrophilia (absolute counts >8000/cu.mm.)
Acute Infections
Localized (eg. pneumonia, meningities, tonsillitis)
Generalized (eg. acute rheumatic fever, septicemia, cholera)
Inflammation (eg. Vasculitis)
Intoxications (metabolic acidosis, uremia, acute gout), poisonings (eg. mercury. epinephrine, black widow spider)
Acute hemorrhage or hemolysis of red blood cells
Tissue necrosis (eg. AMI, burns, Gangrene)
Physiological (eg. exercise, stress, obstetric labor, menstruation)

Toxic Granulation: large dark blue granules in the cytoplasm of neutrophils, associated with severe infection,sepsis, chemical poisoning, and other toxic states.

Causes of Neutropenia (Absolute count <1800/cu.mm.)
Decreased/defective production
1) Infections: bacterial (eg. Overwhelming infection, septicemia, typhoid, paratyphoid) viral infections (infections mononucleosis, hepatitis, influenza, measles, rubella), rickettsia, others (malaria, kala azar)
3) Drugs-chemicals (antibiotics, analgesics, antithyroids.and radiaion
4) Hemopoietic diseases (Aluekemic Leukemia, aplastic anaemia and splenic sequestration
5) Autoimmune and isoimmune neutropenias
6) Immune defects like infertile genetic agranulocytosis

Causes of lymphocytosis (>6500cu.mm. in adults >7200/cu.mm. adolescents >9000/cu.mm. in children and infants)
Infections Pertusis, infectious lymphocytosis, infectious hepatitis, CMV infections. Mumps, rubella, varicella, toxoplasmosis, TB) others like throtoxicosis. Addision’s disease, neutropenia with relative lymphocytosis, lymphatic leukemia, chron’s disease, ulcerative colitis and infancy (normal count 40-60%) called relative lymphocytosis.

Causes of lymphocytopenia (<1500>3000 in children)
Increased destruction (chemotherapy or radiation treatment, corticosterioids) increased loss via GI tract (thoracic duct drainage obstruction to intestinal lymphatic duet drainage). Congestive heart failure, decreased production (Aplastic anaemia, malignancy, AIDS)

Basophilia (50/cu.mm. or >1%)
May be first sign of blast crisis or accelerated phase of CML.
Persistent basophilia may indicate unsuspected myeloproliferative disease.

Causes of Basopenia
Hyperthyroidism, pregnancy, irradiation, chemotheraphy, glucocorticoid administration, acute phase of injection

Causes of moncytosis (>10% of differential: absolute count>500/cu.mm.)
Monocytic leukemia, other myeloproliferative fisorder, lymphomas, lipid storage diseases, postsplenectomy, protozoal and some rickeusial infections, SBE. TB, brucellosis sarcoidosis. RA. SLE.

Causes of Eosinophilia (>400/cumm. diurnal variation with highest level in morning)
Allergic diseases (bronchial asthma, hayfever, urticaria, allergic, rhinitis)

Parisitic infectations, mycoses, scarlet fever, erythema multiformes SLE, RA Skin diseases (eg. pemphigus)
Highest levels occur in trichinosis, clonorchis sinesis, dermatitis hepetiformis.

8. Platelet Count (PC)

Normal Range 1,50,000 - 400,000/cu.mm.

Thrombocytosis in
After administration of epinephrine due to splenic contraction or after splenectomy MPD. trauma (eg. surgery, injury chilbirth) and stress

Thromocytopenia in
Bone marrow depression, hypersplenis, viral infections (esp. in dengue fever), drug hypersensitivity, antiplatelet antibodies (IgG and IgM). increased platelet consumption in TTP, DIC, Septicemia.

II. Peripheral Blood Film (PBF)

Indications
Peripheral smear is done for typing anemia, to confirm RBC indices or indicate leukemia or other conditions.

RBC inclusions
Basophilic or polychromatophilic macrocytes increased erythropoiesis due to hemorrhage or hemolysis): microcytes with stippling (thalassemia, lead poisoning): Cabots’ rings (severe hemolytic anemias, PA): Howell - Jolly bodies (megaloblastic anemia, thalassemia, hyposplenism, splenectomy): Pappenheimer bodies (Sideroblastic anemia, thalassemia, lead poisining. pyridoxine unresponsive or responsive anemias): Heinz bodies (congenital G-6-PD deficiency, drug induced hemolytic anemias): plasmodium throphozoites (malaria): reticulocyte

Abnormally shaped RBCs

Round- Macrocytes (increased erythropoesis): macrocytes (liver disease, hypothyroidism , alcoholism): macro-ovalocytes (hypochromic anemias), spherocytes (hereditary spherocytosis, recent blood transfusion): stomatocytes (hereditary stomatocytosis, acute alcoholism) target cells (HbC disease or trait, HbD, HbE, HbS, thalassemia, iron derficiency anemia, liver disease, post spelenctomy)

Elongated- Elliptocytes (herediatary, macrocytic anemia) ovalocytes (megaloblastic anemia) Teardrop cells (spent polycythemia, myelofibrosis, thalassemia): Sickle cells (Sickle cell disorders ) HbC crystalloids (HbC trait or disease)

Spiculated-Acanthocytes (Abetalipoproteinemia, post splenectomy, fulminating liver disease) Burr cells (Stomach cancer, GI bleeding, uremia, Bite cells (hemolysis due to drugs) RBC fragmentation (Cytotoxic chemotherapy, autoimmune hemolytic anemia, deficiency anemias, acute leukemia, inherited structural abnormality of RBC membrane protein spectrin)
III. Reticulocyte Count (RC)

Introduction
Also known as poor man’s bone marrow test
The reticulocyte count is a fairly accurate reflection of erythropoietic activity therefore their number increases whenever RBC's. there are being rapidly manufactured.

Normal Range

0.5 - 1.85% of erythrocytes.
Absolute count - 29.000-87.000/cu. mm
Infants 2-6% Newborns - 30-50% decrease to 1-2% in first week of life

Indications

· Diagnosis of ineffective erythropoiesis or decreased RBC formation
· Increase indicates effective RBC' production used as :
Index of therapeutic response to iron. folate or vitamin B12 therapy and blood loss : Monitor treatment response after bone marrow suppression and transplantation : Monitor response to erythropoitein therapy

>Increased in

After blood loss or increased RBC destruction. After iron therapy after specific therapy for megaloblastic anemia and other hematologic conditions like polycythemia, metastatic carcinoma in cone marrow.

Ineffective erythropoiesis or decreased RBC formation (severe autoimmune type of hemolytic disease, megaloblastic disorders) alcoholism myxedema.

IV. Erythrocyte Sedimentation Rate (ESR)

Introduction

ESR is the rate at which RBC' s settle down
Sedimentation rate depends on various factors like :
Rouleaux formation (Rouleaux formation is directly proportional to concentration of fibrinogen and globulin in plasma. it is retarded by albumin) ; viscosity of plasma (ESR decreases if viscosity increases): ratio of cells to plasma (decreased ratio leads to increase Rouleaux formation) ; nature of anticoagulant used.

Normal Range (mm in 1 hr )

Westergren
Wintrobes
Males females
0-13 0-20
Males Females Children Newborns
0-10 0-15 0-13 0-2

>Increased in

Tissue damage or inflammation, anemia, any toxic or infective condition (acute or chronic), malignancies, nephrosis, physiological increase in females, pregnancy, increase in temperature.

Polycythemia, leukemia, hypofibrinogenemia, pernicious anemia, CHF, protein shock (eg. burns, severe allergic reactions), physiological decrease in newborns, decrease in temperature.

V. Bleeding Time (BT)

Normal Range
3 - 9.5 minutes

Indications and Interpretations
· BT is functional test-of primary hemostasis
· BT is single screening test for platelet functional or structural disorders, acquired (eg. uremia) or congenital.
· To work up for coagulation disorders in patients, having history of excess bleeding even with normal platelet count.
· Normal in all other disorders of coagulation except VWF deficiency and some cases of very low plasma fibrinogen.
· Prolonged BT due to uremia, Von Willebrand's disease, congenital platelet function abnormalities or severe anemia.
· No value in performing BT if platelet count<10000/cu.mm.usually indicates impaired platelet function (eg. due to aspirin) or Von Willebrand's disease
· BT increased out of proportion to platelet count suggests von Willebrand’s disease or qualitative platelet defect.

>Usually prolonged in
Thrombocytopenia: Platelet count < 100,000/ cu. mm. and usually < 80,000/ cu. mm before BT becomes abnormal and < 40,000/cu.mm. before abnormality becomes pronounced. Platelet function disorders

=Usually normal in
Hemophilia, severe hereditary hypoprothrombinemia or hypofibrinogenemia

VI.Coagulation Time/Clotting Time (CT)

Normal range

6-17 minutes (glass tube), 19-60 minutes (Siliconized tubes)

Indications and interpretations
Former routine method for control of heparin therapy but now replaced by a PTT Routine preoperative screening.

Prolonged in

Sever deficiency (<6%) or any known plasma clotting factors except factor XIII and factor VII, afibrinogenemia of presence of circulating anticoagulant (including heparin).

Normal in

Thrombocytopenia, deficiency of factor VII, Von Willebrand's disease, mild coagulation defects due to any cause.

VII. Prothrombin Time (PT) &INR

Normal range

11-16 seconds

Indications

Control of long - term oral anticoagulant therapy with coumarins and indanedione derivatives; Evaluation of liver functions (PT is the most useful test of impaired liver synthesis of prothrombin complex factor [ factor II, VII, IX, protein C & S ]; Evaluation of coagulation disorders - screen for abnormality of factors involved in extrinsic pathway ( factor V,VII,IX, prothrombin, fibrinogen ). Should be used with aPTT.

Prolonged by defect in

Factor I, II, V, VII and X

Prolonged in

Inadequate vitamin K in diet, premature infants, newborn infants of vitamin K deficient mother, poor fat absorption (obstructive jaundice, collitis, Steatorrhoea) . Severe liver damage (hepatitis, poisoning), anticoagulant drugs, familial hypoprothrombinemia.

VIII.Activated Partial Thromboplastin Time (aPTT)

Introduction

aPTT is the best screening test for disorders of coagulation; it is abnormal in 90% of patients with screening test for disorders of coagulation factors that contribute to thrombin formation except factor VII and XIII. The test may not detect mild clotting defects which seldom cause significant bleeding.

Normal Range

25-38 seconds

Indications and Interpretation

Monitor heparin therapy; Screen for hemophilia A and B.

Prolonged by

Defect in following factors: I, II, V, VIII, IX, X, XI, XII; Presence of specific inhibitors of clotting factors Heparin, Warfarin and Lupus anticoagulant.

Normal in

Thrombocytopenia, platelet dysfunction, Von Willebrand's disease, isolated defect of factor VII.

.
D-Dimer test
The NycoCard D-Dimer test is a rapid 3-minute test for the activation status of the fibrinolysis system. It can also be used for the exclusion of thromboembolic disease.

Test specific information
Sample volume: 50 µL
Assay time: 3 minutes
Sample material: Plasma
Measuring range: 0.1 - 20 mg/L
Clinical use of D-Dimer
Exclusion of thrombotic disorders such as Deep Venous Thrombosis (DVT) and Pulmonary Embolism (PE)
Diagnosis of DIC (Disseminated Intravascular Coagulation)
Early detection of fibrinolytic processes
Monitoring the course of thrombolysis and response to thrombolytic treatment

BIOCHEMISTRY

I. Blood Glucose

Indications
Diagnosis of diabetes mellitus [defined by WHO as unequivocal increase of fasting serum (or plasma) glucose > 126mg\dL on more than one occasion or any glucose level > 200mg\dL]; Control of Diabetes Mellitus; Diagnosis of hyperglycemia.

Normal Range

Fasting Post Prandial (2hrs.)
60-100mg\dL <140mg\dL

>Higher Levels seen in

Diabetes Mellitus including: Hemochromatosis, Cushing's syndrome, Acromegaly Increased circulating epinephrine due to - Adrenaline injection, pneochromocytoma stress, Acute and chronic pancreatitis, Effect of Drugs like (corticosteroids, estrogens, alcohol, phenytoin thiazides.)

Pancreatic disorders (eg. Islet, cell tumor, pancreatitis, glucagon deficiency); Extra pancreatic tumors (eg. carcinoma of adrenal gland and stomach, fibrosarcoma); Hepatic disease (eg. hepatitis, poisoning, cirrhosis, primary or metastatic tumor); Endocrine disorders (hypopituitarism, Addisons disease, hypothyroidism); Functional disturbances (eg. Postgastrectomy, gastroenterostomy, autonomic nervous system disorders); Pediatric anomalies (eg.prematurity, infant of diabetic mother); Enzyme disease

Glycosylated Hemoglobin (HbA1c)
Research has proven that good control & specific monitoring of diabetes is the best way to prevent or delay complications of the disease, Complications that include heart disease, blindness, nerve damage and kidney damage. While your daily blood testing tells you how your blood sugar is doing right then, allowing you to make necessary changes in medicine, food and exercise, it doesn’t give you a picture of your long-term diabetes management success. To do that, there is glycosylated hemoglobin testing.
The glycosylated hemoglobin test, or Hemoglobin A1c (HbA1c), is a test used to give doctors the most accurate picture of patients overall diabetes control.
Here’s how it works.
Sugar that is not used for energy is left in the blood, where it attaches itself to the hemoglobin, which is the part of the red blood cell that carries oxygen, in a process called glycosylation. The more glucose there is in the bloodstream, the more glucose builds up in the cells. This binding of sugar to molecules in cells is one way diabetes causes physical damage and health problems.
The HbA1c test measures the amount of sugar that is attached to the hemoglobin in red blood cells, with results given as a percentage. Athough different laboratories may use different testing methods; the percentage that occurs in people without diabetes is usually about six percent. Because red blood cells live in the bloodstream for about four months, the HbA1c test shows the average blood sugar for the past several months, similar to the way the batting average of a cricket player is calculated over a period of time.
Unlike regular blood sugar test, the HbA1c test is not affected by short-term changes. The chart below shows the average daily blood glucose levels for four different HbA1c values.
HbA1c Value Average daily blood glucose level over past three months
6%
120 mg/dl (pretty good)
8%
180 mg/dl (not too bad)
10%
240 mg/dl (not good)
13%
330 mg/dl (dangerous)
The HbA1c test should be done every three to six months, depending on your treatment program and level of control.

II. Oral Glucose Tolerance. Test (OGTT)

Introduction

OGTT is done after overnight fasting for 10-16hrs. Certain drugs should be stopped several weeks before the test (eg. oral diuretics O.C's phenytoin). Lodding dose of glucose [adults = 75gms for children 1.75gm\kg (of ideal body weight in obese children but never> 75gms). Pregnancy =100gms] is consumed in 5mins. Blood sample drawn at fasting. 30, 60, 90,120 mins.

Indications

OGTT should be reserved principally for patients with "borderline" fasting plasma glucose levels (i.e. fasting range 110-140 mg\dL).
All pregnant women should be tested for gestational diabetes with a 5-gm dose at 24-28 weeks of pregnancy: if result abnormal, OGTT should be performed after pregnancy.

Increased tolerance in

Pancreatic is let cell hyperplasia or tumor, poor absorption from GI tract in intestinal disease (eg. Steatorrhoea, sprue, colic disease), Hypothyroidism Addison's disease, liver disease, hypopituitarism.

Decreased tolerance in

Diabetes Mellitus - For diagnosis of diabetes in nonpregnant adults, at least two values of OGTT should be increased ( or fasting serum glucose >140 mg/dL on more than one occasion and other causes of transient glucose tolerance must be ruled out.
Other causes of decreased tolerance are hyperthyroidism. hyperlipidemia, steroid effect Cushing's effect, administration of ACTH or steroids. pregnancy.
Drugs like indomethacin, various neuroactive drugs [ phenothiazines, tricycles, litnium, halparidol], heparin.

III Lipid profile
Lipid profile is done to detect abnormalities in the levels and metabolism of plasma lipids and lipoproteins. Various tests done under lipid profile are:

1.Total Serum Cholesterol

Indications

Monitoring for increased risk factor for CAD; Screening for primary and secondary hyperlipidemias: Monitoring of treatment for hyperlipidemias

Normal Range

130-200 mg/dL: Total: 32-76 mg/dL

Increased in

Hyperlipoprotinemias; Cholesterol storage diseases) ; Biliary obstruction (stone, carcinoma, cirrhosis) ; von Gierke's disease; Hypothyroidism; Nephrosis; Pancreatic disease (DM, chronic pancreatitis) ; Drug Use (e.g. progestins, corticosteroids, anabolic steroids)

Decreased in

Severe liver cell damage (due to chemicals, drugs, hepatitis); Hyperthyroidism; Malnutrition; Infection and inflammation; Drugs

2. High Density Lipoprotein (HDL) Cholesterol

Introduction

Levels of HDL are inversely related to risk of CAD.
For every mg\dL decrease in HDL, risk of CAD increases by 2-3%

Indications

Assessment of risk of CAD

Diagnosis of various lipoproteinemia

Normal Levels

Men Women
>35mg\dL >40mg\dL

(>60mg\dL is negative risk factor for CAD)

Increased in
Vigorous exercise; Moderate consumption of alcohol; Increased clearance of triglyceride (VLDL); Familial lipid disorders with protection against atherosclerosis (illustrates importance of measuring HDL to evaluate hypercholesterolemia); 1 in 20 adults with mild increased total cholesterol levels (240-300mg\dL); Secondary to increased HDL (>70mg\dL);
Hypobetalipoproteinemia
( <32mg\dL in men, <38mg\dL in women)

Decreased in
Stress and recent illness (e.g.AMI, stroke, surgery, trauma);Starvation, nonfasting sample; Obesity and lack of exercise; Cigarette Smoking; DM, Hypo and Hyper thyroidism; Acute and chronic liver disease; Genetic disorders; Familial hypoalpha lipoproteinemia

3.LDL (Low Density Lipoprotein) cholesterol

Introduction

LDL levels are directly related to risk for CAD

Indication

Assess risk and decide treatment for CAD

The following factors also increase your risk of CAD:
Diabetes
High blood pressure
High LDL "bad" cholesterol
Low HDL "good" cholesterol
Menopause
Not getting enough physical activity or exercise
Obesity
Smoking

Normal Levels

No CAD and < 2 risk factors < 160mg/dL
No CAD but > 2 risk factors < 130mg/dL
Presence of CAD < 100mg/dL

Increased in

Familial hypercholesterolemia and combined hyperlipidemia: DM and hypothyroidism; Chronic renal failure; Diet high in cholesterol and total and saturated fat; Pregnancy; Cholesterol ester storage disease; Drug use ( e.g. anabolic, steroids, betablockers, progestins, carabamazepine).

Decreased in

Severe illness; Abetalipoproteinemia;
Monitoring laboratories also report various ratios; Total cholesterol/HDL ratio- Low risk; 3.3-4.4, Average Risk ; 7.1-11.0, high risk >11.0.

4.Triglycerides (80% in VLDL, 15% in LDL)

Introduction

Triglyceride levels are not a strong predictors of atherosclerosis of CAD and may not be an independent risk factor. Triglyceride levels are inversely related to HDL cholesterol levels.

Normal Range

20-170mg/dL

Classification

Normal Borderline high High Very high
<200mg/dl>1000mg/dL

Increased in

Genetic hyperlipidemia (eg. Lipoprotein lipase deficiency. apo c.II deficiency, familial triglyceride abnormality, dysbetalipoproteinemia); Secondary hyperlipidemias (gout, pancreatitis.
Acute illness [ eg. in AMI rises to peak in 3 weeks and increase may persist for 1 year] ;
Drug use (eg. thiazides, steroids, amiadarones interferon)

Decreased in

Abetalipoproteinemia; Malnutrition; vigorous exercise; Drugs (eg. ascorbic acid, clofibrate. phenformin, metformin. progestin).

IV Renal Profile

Is done to evaluate kidney functions. Various tests included are.

1.Blood Urea Nitrogen (BUN)

Introduction

BUN correlates with uremic symptoms better than serum creatinine

Normal Range

Adults Neonate

10-23 mg/dL 5-16mg/Dl

6-8mg/dL : associated with overhydration states
50-150mg/dL : implies serious impairment of renal junction
150-250mg/dL : is conclusive evidence of severally impaired glomerular filtration.

Indications

Differential diagnosis of various renal disorders:
Evidence of hemorrhage in GI tract :
Assessment of patients receiving nutritional support or excess catabolism (burns. cancer)

Increased in
Impaired kidney function: Prerenal azotemia - any case of reduced renal blood flow :
Congestive heard failure: Salt and water depletion (vomiting. Diarrhea sweating) :
Shock: Post renal azotemia = any obstruction of urinary tract (increased BUN/Creatinine ratio): Hemorrhage into GI Tract : Acute myocardial infarction : Stress.

Decreased in
Diuresis (e.g. with overhydration. often associated with low protein catabolism) : Severe liver damage (Drugs poisoning. hepatitis. other) : Increased utilization of protein for synthesis (Late pregnancy. infancy. acromegaly. malnutrition) : Diet (low protein and high carbohydrate. impaired absorption. malnutrition) : Nephrotic syndrome : SIADH.

Creatinine

Introduction

Serum creatinine is the most specific and sensitive indicator of renal disease. Use of BUN and creatinine levels together is more informative in renal disorders.

Normal Range

Male Female Fetal Pregnancy
0.7-1.4 mg/dL 0.6-1.1mg/dL 0.4-0.9 mg dL 0.4-6mg/dL

Indications
Diagnosis of renal insufficiency

Increased in

Diet [ingestion of creatinine (roast meat)] Prerenal azotaemia; Prerenal azotaemia; postrenal azotemia ; Impaired kidney function, 50% of renal function is needed to increase serum crestinine from 1.0-2.0 mg/dL. Therefore not sensitive to mild moderate renal injury.

Decreased in

pregnancy-normal value is 0.4-0.6 mg/dL >0.9 mg/dL is abnormal and should alert clinician to further diagnostic evaluation.

2.URIC ACID ?????NORMAL

Introduction

Uric acid levels are very liable and show day to day and seasonal variation in same person, also increased by emotional stress, total fasting, increased body weight Uric acid levels do not correlate with the severity of kidney damage; urea and creatinine are better.

Indications

Monitor chemotherapeutic treatment of neoplasms to avoid renal urate deposition with possible renal failure; Monitors treatment of Gout.

Increased in

Renal failure; Gout and also in 25% of relatives of patients of Gout; Asymptomatic hyperuricemia; Leukemia, multiple myeloma, malignancies, Hemolytic and sickle cell anemia; Toxemia of pregnancy; Psoriasis(1/3 cases);Drug use (barbiturates, methyl alcohol,salicylates, polycystic kidney disease, atherosclerosis and hypertension (serum uric acid is increased in 80% of patients with elevated serum triglyceride).

Decreased in

Drugs (ACTH, high dose salicylates, probencid, cortisone); Wilson’s disease, Fanconi's syndrome, celiac disease, xanthuria.

V. Liver Profile

Is done to evaluate liver functions, various tests included are:

1. Serum Bilirubin

Introduction

Determinations of serum bilirubin in clinical laboratory measures two pigment fractions: (1) Ther water soluble conjugated fraction that gives a direct reaction with diazo reagent and consists largely of conjugated bilirubin. (2) The lipid soluble indirect-reaction fraction and represents primarily unconjugated bilirubin.

Indications

Differential diagnosis of disease of hepatobiliary system and pancreas and other causes of jaundice

Normal levels

Total Bilirubin Direct bilirubin
0.3-1.0mg\dL 0.1-0.5mg\dL

Increased levels

Direct (conjugated) Bilirubin in

20-40% of total: more suggestive of hepatic than post hepatic jaundice. 40-50% of total; occurs in either hepatic or post hepatic than hepatic jaundice; > 50% of total; more suggestive of post hepatic than hepatic jaundice;

Total serum bilrubin > 40mg\dL indicates hepatocellular rather than extra hepatic obstruction.

Conditions

. Hereditary disorders (e.g. Dubin- Johnson syndrome Rotor's syndrome).
. Biliary duct obstruction (Extra and Intrahepatic).
. Hepatic cellular damage (Viral, toxic alcohol\drug related).
Infiltration. Space- occupying lesions (e.g.Metastatic tumour, Abscess, Granulomas)

Increased unconjugated (Indirect) Bilirubin in

Increased bilirubin production; Hemolytic diseases (e.g.hemoglobino pathies, RBC enzyme deficiencies, DIC, autoimmune hemolysis); Ineffective erythropoiesis; Blood transfusions; Hematomas; Heriditory disorders (e.g. Gilbert’s disease, Crigler-Najjar syndrome); Drugs causing hemolysis.

2. Total Serum Proteins

Introduction
Extensive liver injury may lead to decreased blood levels of albumin, prothrombin, fibrinogen and other proteins synthesized exclusively by hepatocytes. Serum protein levels are neither early nor sensitive indicators of liver disease.

Normal Range
5.5-8.5mg\dL

Indications

Screening for nutritional deficiencies and gammopathies.

>Increased in

Hypergammaglobulinemias, Hypovolemic states.

Nutritional deficiency (e.g. Malabsorption, Kwashiorkor, Marasmus); Decreased or ineffective protein synthesis(e.g. severe liver disease, a gamma globulinemia); Increased loss (e.g. Renal nephrotic syndrome); GI disease (e.g. protein losing enterpathy, surgical recession); Severe skin disease (e.g. burns eczema); Blood loss, Plasmapheresis, Increased catabolism (e.g. fever inflammation, hyperthyroidism, malignancy); Dilutional (e.g.IV fluids administration, SIADH, water intoxication).

3. Serum Albumin

Introduction

Albumin is quantitatively the most important serum protein synthesized by liver.

Indications

Marker of disorders of protein metabolism (e.g. nutritional, decreased synthesis, increased loss).

Normal Range
2.5-5.5mg\dL

>Increased in

Dehydration (relative increase) I\V albumin infusion

Same as for total serum proteins

4. Serum Globulin

Introduction

Globulins are produced by variety of tissues including liver, serum globulins include alpha and beta globulins as well as serum immunoglobulins.

Indications

To evaluate chronic liver diseases and cirrhosis (increases to varying degrees).

>Increased in

Chronic liver diseases and cirrhosis; Increase may be present in non-hepatic disorders or may reflect increased stimulation of peripheral reticuloendothelial compartment due to shunting of antigens past the liver and impaired clearance by Kuffer cells.

5. Serum Aspartate Aminotransferases [AST]\ Glutamic-Oxaloacetic Transminase [SGOT]

Introduction

Aminotransferases like ALT and AST that are concentrated in liver used as indicators of hepatocellular damage. Both parallel to each other but in alcohol related disease ALT is lower than AST.

Indications

Differential diagnosis of diseases of hepatobiliary system and pancreas; Repeat testing to establish chronicity of viral hepatitis; To check hepatotoxicity of a drug.

Men women 0-3years
15-45U\L 5-30U\L 20-60U\L

>Increased in

Liver disease: Acute viral infections e.g. viral hepatitis A.B.C (value is increased up to 50 times the normal, peak levels upto 400-4000 U or more are reached during the icteric phase and gradually decline during recovery phase); Hepatotoxic drugs and chemicals
Musculoskeletal disorders (Myoglubinuria); Acuter myocardial infraction; Acute pancreatitis; All common fevers (value raised upto40-100 U) e.g. Malaria, typhoid, extra pulmonary tuberculosis, dengue fever.

6. Serum Alkaline Aminotransferases (ALT)\ Serum Glutamic Pyruvic Transaminase (SGPT)

Introduction

See AST

Normal Range

Males Females 1-3years
10-40 U\L 5-35U\L 5-45U\L

Increased in

See AST

Other causes are: Obesity (not AST); Severe preeclampsia (both); Rapidly progressing acute lymphoblastic leukemia (both), levels in females approximately 75% of those in males.

7. Alkaline Phosphatase (ALP)

Introduction

ALP is active not only in liver but also in bone, intestine and placenta. ALP is the best indicator of biliary obstruction but does not differentiate intrahepatic cholestasis from extrahepatic obstruction. It increases out of proportion to other LFT's. It increases before jaundice occurs. Higher values (>5 x normal) favor obstruction and normal values virtually exclude this diagnosis.

Men Women Children
65-260 U\L 50-130U\L upto 9yrs 145-420U\L
9-15yrs 135-525 U\L

Indications

Diagnosis of causes and monitoring of course of cholestasis; Also for diagnosis of various bone disorders (e.g. Paget's disease, osteogenic sarcoma)

Increased in

Any obstruction of biliary system (e.g.stone, carcinoma, primary biliary crirhosis, congential bile duct atresia; Increase in early infiltrative) (e.g. amyloid and space-occupying diseases of the liver e.g. tumour, granuloma, abscess); Slight increase in liver parenchymal disease (e.g. cirrhosis, hepatitis) and congestive heart failure; Pregnancy; Children (because of increased bone formation).

VI.Cardiac Profile

Cardiac profile includes a number of enzymes. These enzymes called serum cardiac markers are released into blood in large quantities from necrotic heart muscle after myocardial infraction. These cardiac markers are:

1. Creatine phosphosphokinase (CK)

Introduction

CK is found in heart muscle skeletal muscle and brain . An important drawback of total CK is that it lacks specificity for myocardial infraction as CK may be elevated with skeletal muscle trauma.

Indications

Marker for cardiac injury or diseases (It rises in 90-93% of patients with acute MI> CK rises within 4-8hrs. and returns to normal by 48-72hrs.): Measurement of choice for skeletal muscle disorders.

Normal range

Males Females.
55-170U\L 43-135 U\L

Increased in

Necrosis of cardiac muscle; AMI; Cardiac contusion; After thoracic\open-heart surgery; Myocarditis, cardiomyopathies and collagen diseases; Prolonged supraventricular tachycardia; Coronary angioplasty and angiography (Transient).

It is also increased in: Necrosis inflammation or acute atrophy of straited muscle; Drugs and chemicals (cocaine, alcohol, emetine); 50% of patients with extensive brain infarction; CK levels are frequently elevated after intramuscular infection.

2. Creatinine kinase MB fraction

Total CK can be separated into 3 fractions (isoenzymes): CK-BB (CK-1) found predominantly in brain and lungs; CK-MM (Ck-3) found in skeletal muscle and hybrid CK-MB (CK-2) found predominantly in cardiac muscle and is most widely used early marker of myocardial injury.

Indications

CK-MB is present gold standard for diagnosis within 24hrs of onset of symptoms of MI; Detect reinfaraction or extension of MI after 72hrs; Document repurfusion after thrombolytic therapy.

Normal levels
<5% (MB\total CK); < 10mg\mL (mass)

Increased in

Necrosis and inflammation of cardiac muscle and also skeletal muscle (see total CK pg); Endocrine disorders
Some infections:
Other condions: Malignant hyperthermia; Reye's syndrome; Peripartum period; Hyperthyroidism and chronic renal failure; Neoplasms ( Prostate, breast ).

3.Lactate Dehydrogenase (LDH)

Introduction

Total LDH is actually a group of individual isoenzymes concentrated in different tissues like heart, liver, kidney, cerebrum, RBC, skeletal muscle, lung, spleen and skin.

Normal Range

Neonate infant child Adult
160-1500U/L 160-360U/L 150-300U/L 100-250U/L

Indications

Now replaced by cardiac troponins as late markers for AMI. May be useful marker for alveolitis (fibrosing\allergic), hemolysis.

Increased in

Cardiac diseases- AMI (LD increases in 10-12hrs. peaks in 48-72hrs and lasts for 10-14days); AMI with CHF may show increase of LD-1 and LD-5: Mild elevation in coronary insufficiency; cardiovascular surgery; Acute myocarditis and rheumatic fever.

Also increases in various diseases of: Liver (cirrhosis, hepatitis, metastatic carcinoma, Hematologic (anemias) and lungs (pulmonary embolus and infarction).

4. Cardiac Troponins T and I

Introduction

Caridiac troponins are very specific to myocardium and therefore can differentiate a myocardial injury or skeletal muscle injury. can be detected in patient's blood 3- 6 hours after onset of the chest pain, approaching peak level within 16 -30 hours. Cardiac Troponin is also useful for the late diagnosis AMI, because elevated concentrations can be detected form blood even 5-8 days after onset.

Indications

Cardiac Troponins T and I have replaced other diagnostic enzymes for MI like LD CK MB and AST: AMI when CK-MB may be increased by skeletal muscle injury; Serial measurements to assess reperfusion after thrombolytic therapy and as indicator of cardiac allograft rejection.

Normal Range

Troponin I Troponin T
<1.6mg\dL <0.1mg\dL

Increased in

Even mild cases of myocardial necrosis (e.g.Anoxia, contusion, inflammation) even without ECG changes in AMI CTn's begin to increase in about 4-6hours peak at about 11hrs and return to reference range in 10 days or more.

AST\SGOT

In acute MI, AST has been replaced by other enzymes for diagnosis, Increase appears within 6-8hrs; peaks in 24hours, levels usually return to normal in 4-6hrs. For details see pg.20.

VII. SERUM ELECTROLYTES

1. Total calcium

Introduction

A total 1-2 kg of calcium is present in the average adult. Ninety percent of it is in the skeleton. The calcium in ECF is only a minor fraction of the total pool and is critical for a variety of functions and is remarkably constant. Calcium in plasma is free ions, ions bound to plasma proteins

Total serum protein and albumin should always be measured simultaneously for proper interpretation of serum calcium levels, because 0.8mg of calcium is bound to 1.0gm of albumin in serum; to correct add 0.8mg\dL for every 1.0g\dL that serum albumin falls below 4.0g\dL binding to globulin affects calcium only if globulin > 6g\dL.

Normal Range

8.9-10.7 mg\dL

Indications

Diagnosis of paratyphoid dysfunction, hypercalcemia of malignancy. [90% of cases of hypercalcemia are due hyperparathyroidism, newoplasms or granulomatous diseases. Hyercalcemia of sarcoidosis, adrenal insufficiency and hyperthyroidism tend to be present in clinically evident disease].

Increased in

Hyperparathyroidism [primary\secondary (Acute +chronic renal failure, ostomalaria with malabsorption]; Malignant tumors Drug use [e.g. vitamin D intoxication, milk-alkali syndrome, diuretic use, estrogens, androgens, lithium, tamoxifen, vit A and thyroid hormone use]; Chronic renal failure; Endocrine conditions [Hyperthyroidism, Cushing's syndrome adrenal insufficiency, acromegaly,pheochromocytoma,MEN syndrome ]; Acute osteoporosis

Decreased in
Hypothyroidism and pseudohypoparathyroidism ; Malabsorption of calcium and vitamin D ; Obstructive jaundice ; Chronic renal disease with uremia and phosphate retention Fanconi’s syndrome, renal tubular acidosis; Insufficient ingestion; Drug use [ cancer chemotherapy drugs, fluoride intoxication, certain antibiotics, anticonvulsant drugs ]; Neonate born of complicted pregnancies

2. Inorganic Phosphate
Introduction
Phosphorus is the most abundant intracellular anion and is critical for membrane structure, transport and energy stroage.Of the average 700g of phosphorus in the body, 85% is skeleton, 15% in soft tissues and 0.1% in ECF.

Normal Range

Neonate Adult
4.6 - 8mg/dL 2.8-4.6mg/dL

Indications

Phosphorus levels should be monitored in renal and GI disorders. Effect of drugs.

Increased in

Most causes of hypocalcaemia except vitamin D deficiency; Acute or chronic renal failure with decreased GFR; Increased tubular reabsorption of phosphate [Hypothyroidism, secondary hyperparathyroidism, Addison's disease, hyperthyroidism, acromegaly, sickle cell anaemia ]; Increased cellular release of phosphate [ excessive intake, massive blood transfusions, hemolysis. Milk-alkali syndrome]

Decreased in

Renal or intestinal loss Decreased intenstinal absorption [Alcoholism, DM, Acidosis, Sepsis.

3.Sodium

Introduction

80-90% of all Na + is extracellular and the ECF volume is reflection of total body Na+ content. Na+ excess or deficit manifests as oedema or hypovolemia respectively. Change in Na+ content are manifested as ECF volume.
Normal Range
135- 145meq/L

Indications
Diagnosis and treatment of dehydration and overhydration; Determination of blood Na+ and K+ levels is done to changes in Na+ and K+ during therapy; it is least useful in diagnosis or in estimating net ion losses;

Hypernatremia in

Dehydration is the most frequent overall clinical finding in hypernatremia that occurs due to:

Deficient water intake (either oral or Intravenous); Excess kindly water output (diabetes inspidus, osmotic diuresis); loss from burns ); Excess GI tract output (server vomitting and diarrhea, accidental sodium overdose, High protein tube feedings; Hypernatremia 'essential' [due to hypothalamic lesions

Hyonatremia in
Sodium and water depletion; GI loss (vomiting, diarrhoea), loss from skin (excessive sweating and burns ), loss from kidney (Diuretics,chronic renal insufficiency with acidosis,metabolic loss (stravation with acidosis, diabetic acidosis); Endocrine loss (Addison's disease, suddenwithdrwal of long term steroid therapy); Excessive water\dilutional hyponatermia in excessive water administration, CHF, cirrhosis, nephrotic syndrome, Acute renal failure with oliguria, severe hypoalbuminemia; (IADH) syndrome; False hyponatermia (marked hypertriglyceridemia, marked hyperproteinemia, severe hyperglycemia).

4. Potassium

Introduction

Potassium is the major intracellular cation the amount of K+ in the ECF constitutes less than 2% of the total K+ content. This ICF to ECF K+ ratio (38:1) is principal result of resting membrane potentialand is crucial for normal neuromuscular function.

Normal Levels
Adults 3.5-5mleq\L

Indications

Diagnosis and monitoring of hyper and hypokalemia in various conditions (e.g. diabetic come, renal failure, severe fluid and electrocyte loss, effect of certain drugs); Diagnosis of familial hyperkalemic periodic paralysis and hypeokalemic paralysis.

Hyperkalemia in

Renal failure; Dehydration; Excessive parenteal administration of potassium; Artifactual hemolysis of blood specimen; Tumor lysis syndrome; Hyporeninemic hypoaldosteronism; Spironolactone therapy; Addison's disease and salt-losing congential adrenal hyperplasia; Thrombocytopenia

Hypokalcemia in

Inadequate intake (cachexia or service illness of any type); Intravenous infusion of potassium-free fluids; Renal loss (diuretcis: primary aldosteronism); GI loss (protacted vomitting severe prolonged diarrhoea; GI drainage); Severe truma; Treatment of diabetic acidosis without potassium supplements; Treatment with large doses of adrenocorticotropic hormone, Cushing's syndrome.

5. Chloride

Introduction

Chloride is the most abundant extracellualar anion. In general, CI is affected by the same conditions that affect sodium (most abundant extracellular cation) and in roughly the same degree.

Normal Ranges
96-109 meq\L

Indications

With sodium, potassium and carbondioxide to assess electrolyte, acid-base and water balance

Increased in

Metabolic acidosis assoiciated with diarrhoea with loss of NaHCO3; Renal tubular diseases with decreased excretion of H+ and decreased reabsorption of HCO3 (hyperchloremic metabolic acidosis); Respiratoryalkalosis; Drugs (e.g.NHYCL, I/V) saline, Salicylates, intoxication acltazolamide, corticosteroids phenylbutazone; Diabetes Insipidus, dehydration; Sodium loss>chloride loss (e.g. Diarrhoea, intestinal fistulas).

Decreased in

Prolonged vomiting or suction (loss of HCI); Metabolic acidosis with Chronic respiratory acidosis; Salt losing renal diseases; Adrenocortical insufficiency; primary aldosteronism; Expansion of ECF (e.g. SIADM, hyponatremia, water intoxication, CHF); Burns; Drugs: Alkalosis (e.g. Bicarbonates, corticosteroids, aldosterone); Diuretic effect (e.g. Ethacrynic acid, furesemide, thiazides) (Chronic laxative abuse).

MICROBIOLOGY
The Microbiology Lab consists of the following diagnostic laboratory testing areas: Routine Bacteriology Blood Cultures Urine Cultures Anaerobe Cultures Susceptibility Testing and Antimicrobial Levels Mycology Mycobacteriolgy Bacterial, Fungal, Parasitic, and Syphilus Serology
Urinary Tract Infection
Urinary Tract Infections (UTI) could be of the lower urinary tract encompassing the bladder and urethera or of the upper urinary tract infecting the ureters and kidneys. Because of shorter urethera, bacteria can reach the bladder more easily in females. All areas of the urinary tract above the urethera in healthy humans are sterile, hence urine is normally sterile.
UTI is among the most common reasons patients seek medical care. It is estimated that approximately 10% of humans will have UTI at sometime during their lives.
Causative organisms
E. coli is by far the commonest cause of uncomplicated community acquired urinary tract infections. Other members of Enterobacteriacae can aIso infect. The causative agents are listed in Table 1.
Table 1: Causative agents of UTI
E. coli
Proteus mirabilis
S. aureus
S. saprophyticus
Group B streptococci
Enterococci

Figure 13-3 Three species of Streptococcus
Streptococcus" type="#_x0000_t75">
Gram stains of S. pyogenes, S. pneumoniae and S. mutans. Photomicrographs courtesy of the CDC.
picture of streptococcus
Most strains of Streptococcus which are responsible for diseases are hemolytic on Blood Agar. Hemolytic reactions are classified as α, β or γ according to the appearance of zones around isolated colonies growing on or in the medium:

Neisseria" type="#_x0000_t75">

Figure 13-5 Neisseria
Neisseria, mention coffee bean morphology

A Neisseria isolate. Note the coffee bean morphology of the cells. This is diagnostic for Neisseria. The smear on the left was stained with fluorescent antibodies against the cell wall of N. gonorrhoeae. The smear on the left is a Gram stain.

Diagnosis of pyrexia of unknown origin

CASES referred to as fever or pyrexia of unknown origin often present a diagnostic challenge to practitioners. The main approach to diagnosis is to identify the reason for the pyrexia. Clinical signs are often non-specific and may fluctuate in severity and alter with chronicity. Although it is theoretically desirable not to instigate any treatment before a full investigation has been carried out, in practice this is often difficult and a response to specific therapies can help in the diagnosis. If there are no localising signs, a series of simple screening tests is necessary to try to identify a septic, inflammatory or neoplastic focus.
It is not necessary to conduct all the following.Some investigations with a clinical back ground are selected first
Routine laboratory investigations such as complete haemogram, CRP, urine examination and culture, peripheral blood smear for malarial parasite, TB antigen,antibody, dengue fever, encephalitis (if prevalent) liver function tests, sugar, urea & creatinine, ASO, Widal test,HIV, VDRL, Blood culture, chest X-ray ECG & ultrasonography

Corynebacterium diphtheriae
Clinical Syndromes:
Determined by site of infection, host immunity, and virulence of the organism
Corynebacterium diptheriae: toxigenic strains cause diphtheria in humans
Respiratory disease
Initially: sore throat, low-grade fever; followed by adherent pseudomembrane on the tonsils and pharynx
Later stages include localized damage, bleeding, difficulty in breathing, and myocarditis and peripheral neuritis
Complications from systemic spread of exotoxin to other target organs in the body; eg., heart (concept of "disease at a distance")
Most mortality from systemic toxin-mediated heart failure
Cutaneous diphtheria (extra-respiratory disease)
Acquired by skin contact; organism enters through break in subcutaneous tissue
Chronic non-healing ulcer results

C. diphtheriae and related organisms are collectively termed coryneforms or diphtheroids
Morphology & Physiology: (throat swab & culture)
Microscopy
Methylene blue stain shows metachromatic granules
Gram stain shows Gram-positive pleomorphic rods arranged in perpendicular, parallel, and pallisade formations
Culture
A confirmed diagnosis of diphtheria can only be made by isolating toxigenic diphtheria bacilli from the primary lesion (in the throat or elsewhere)Exudate from the lesion should be inoculated onto blood agar and selective media: cysteine-tellurite agar; serum tellurite agar; Loeffler’s slant:

Small, nonmotile, irregularly staining pleomorphic Gram-positive rods with club- shaped swelled ends but no spores; may be straight or slightly curved
Palisade arrangement of cells in short chains ("V" or "Y" configurations) or in clumps resembling "Chinese letters"
Cells tend to lie parallel to one another (palisades) or at acute angles (coryneforms), due to their snapping type of division Catalase positive

1. BLOOD CULTURE

Introduction

Blood culture is done in patients with clinical findings suggestive of bacteremic state. It should be noted that 25 percent of patients with documented bacteremia have periods without fever.

Indications

Patients with fever and: Unexplained alterations in mental status, funtional status or autonomic status in a previously healthy patient between 5 and 65 yuears; No source if <> 65 years or immuno-compromised; All infants < 3 months

Patients with or without fever and: Rigors or toxic\septic appearance (e.g. Unexplained hypotension, altered mental status, shock); Suspicion of infectious endocarditis or having serious focal infections (e.g. Meningitis, septic arthritis, osteomyelitis), pneumonia or pyelonephiritis with signs of toxicity; Unexplained alterations in mental status functional status or autonomic status at extremes of age and in the immuno compromised.

Caution

It is very essential to know numbers of blood culture sets to be obtained for adequate series in various clinical situations in adults and also type of blood culture bottle to be used. See Tables 1 and 2 below.

Table 1: Number of blood culture sets to be obtained in various clinical situations in adults

No.of sets (minimum) Clinical context

2 sets Etiology is likely to be easily distinguieshed from contaminants and pretest probability of bacteremia is low to moderate

3 sets Skin contaminants are possible cause of infectious process or pretest probability of bacteremia id high or infectious endocarditis is a consideration but with low to moderate pretest probability

4 sets Possible infectious endocarditis where either the preset probability is moderate to high or the patient has recently been on antibiotic

Table No 2: Blood culture bottle type to be used in various clinical situations

Clinical situations Bottles to be obtained

Children <12 years Aerobic bottles only unless patient has peritonitis or fascitis ( in which case draw aerobic and anaerobic cultures)

Adults and children If anaerobic infection is unlikely, use aerobic bottles only

In the immunocompromised, consider a bottle for fungal culture (usually effective in aerobic bottles, but consult the laboratory).
False positive blood cultures can be due to true contamination.

11. AFB MICROSCOPY AND CULTURE

Direct microscopic examination of stained specimen is the most rapids laboratory lest widely available to support a presumptive diagnosis of TB. Acid fast bacillus microscopy for diagnosis of mycobacterium infection can bve done in various specimens like sputum, gastric contents, pleural, fluid, blood, bone marrow, involved tissue, joint fluid, CSF, Urine, peritoneal fluid, pericardial fluid.

Two types of stains detect AFB: Carbol Fuschin (The classic Zeihl-Neelson stain). and the preferred fluorochrome stains (auramine-rhodamine).

A negative AFB smear however, does not rule out active pulmonary TB because microscopy is relatively insensitive when small numbers of bacilli are present. There must be about 5000-10000 bacilli\ml of specimens

Culture

A presumptive diagnosis of TB based on AFB smear is usually confirmed by isolating Mycobacterium tuerculosis MTB by culture. Sputum cultures are more sensitive for detecting MTB than microscopy.

III. SEROLOGY AND IMMUNOLOGY

1 IMMUNOGLOBIN E (IgE)
The measurement of immunoglobulin E (IgE) in serum is widely used in the diagnosis of allergic reaction and parasitic infection.

Many allergies are caused by the inmunoglobulins of subclass IgE acting as point of contact between the allergen and surface of mast cells. The IgE molecules bind to the surface of the mast cells and basophilic granulocytes. Subsequently, the binding of allergen to bell bound IgE uses these cells to release histamines and other vasoactive substances.

It is important to know whether the reaction is lgE mediated or non-lgE mediated; Measurement of total circulating lgE may also be of value in the early detection of allergy in infants and as a means of predicting future atopic manifestations.
lgE levels show a slow increase during childhood, reaching adult levels in the second decade of life. in general, the total lgE levels increase with the allergies a person has and the number of times of exposure to the relevant allergens significant elevations may be seen in cases of myeloma, pulmonary aspergillosis and during the active stages of parasitic infections.

REFRENCE RANGE
Age Range
0-3 yrs. ND - 46 IV / ml
3-16 yrs. ND - 280 IV / ml
Adult ND - 200 IV / ml

2 VDRL Test [Venereal Disease Research Laboratory Test] TITER

Introduction

VDRL is one of the nontreponomal serological test for syphilis. It detects lgG and lgM antibodies to a cardiolipin - lecithin cholesterol antigen.

Indications and Interpretation

Routine screening of asymptomatic persons. Simple convenient frequent local requirement for premarital and prenatal serology; Diagnosis of symptomatic infection. Does not become positive until 7 days after appearance of chancre. High titer >1.16 usually indicates active disease; Low titer (< 1.8) indicates biological false positive test in 90 percent cases or occasionally due to late or late latent syphilis; Following of titers to determine effect of therapy.
Quantitation of VDRL should always be performed before initiation of treatment.

Interference

May be non reactive in early primary, late latent and late syphilis (appx. 25% cases), or in undiluted serum in presence of actual high titer; Short term false positive (<6>6 months duration) may occur in other treponomal infections, collagen vascular diseases leprosy, malignancy; RA, ANA, ITP, autoimmune hemolytic anaemia, AIDS, thyroiditis.

3. WIDAL TITER

Intorduction WIDAL is the simplest serological diagnostic test for typhoid fever. It measures the agglutinating antibodies to 'O' or 'H' antigens.

Indications and Interpretations

WIDAL is indicated for differential diagnosis of typhoid fever.

In the absence of recent immunization a high titer of antibody to O antigen (>1:160) is consistent with acute typhoid and higher titers (>1:640) are even more suggestive of this condition. {However, other D Salmonella, along with some organisms in group A and B share the antigen used in Widal test which therefore is not specific}. [Antibodies to H antigens may be found even in higher titers but because of their broad cross reactivity, are difficult to interpret]. A four for fold rise in antibody titer between paired serum samples is strong evidence of infection; however, such a rise is of little use in management of acutely ill patient.

Recently developed latex agglutination or coagglutination tests for antibody to the VI antigen appear to be much more specific and sensitive than classic WIDAL tests.

4. Antistreptococcal Antibody Titers (ASOT) TITER

Introduction

Individual determinations depend on various factors (e.g. duration and severity of infection antigenicity) and are of limited clinical value. Serial determinations are most essential; a successive increase in ASOT confirms immunologic response to streptococcal organisms. Antibody appears as early as one week after infection; titer rises rapidly by 3-4 weeks and then declines quickly; may remain elevated for months.

Indications

A high or rising titer is indicative only of current or recent streptococcal infection.
. It has direct diagnostic value in scarlet fever, erysipelas, streptococcal pharyngitis and tonsillitis.
. Indirect diagnostic value in rheumatic fever and glomerulonephirits.
. Detection of sub clinical streptococcal infection
. Differential diagnosis of joint pains of rheumative fever and rheumatoid arthritis (RA).

Conditons Usual ASOT [Todd units]

Normal 12-166
Active rheumatic fever 500-5000
Inactive rheumatic fever 12-250
RA 12-250
Acute GN 500-5000
Streptococcal URI 100-333
Collagen Disease 12-250

False positives: Associated with TB, liver diseases, bacterial contamination.

4. C Reactive protein (CRP) TITER

Intoduction

CRP is an acute phase reactant, quantitative test is superior.

Normal Range
<8mg\dL

Indications and Interpretation
. Inflammatory disorders for monitoring course and effect of therapy,
.Most useful indicator of activity in rheumatic disease (e.g. RA, rheumatic fever);
Infection: Indicates presence of infection.30-35 mg\dL in 80-85 percent of acute bacterial infection <20mg\dL in viral infections.
=> Normal value useful to exclude infection
=> Diagnose postoperative and intercurrent infection

Measurement is particularly useful to monitor response to antibiotic therapy.
Since, atherosclerosis is an inflammatory process, production of CRP starts much ahead of cholesterol deposition in the heart, thus, making CRP an extremely valuable indicator of CVD
There is a 10 fold difference amount the reporting units of conventional and high sensitive CRP tests. The hs-CRP test needs to be evaluated by highly sensitive technique(ELISA, CLIA, RIA)

Increased in

Inflammatory disorders; Ra, rheumatic fever, Reiter's syndrome, vasculitis syndromes; Inflammatory bowel disease, chronic inflammatory disease; Tissue injury or necrosis; AMI, ischemia or infarction of other tissues, rejection of an organ transplant; Malignant tumours; infections;

5. Rheumatoid Factor (RF)

Introduction

Rheumatoid factor is an autoantibody present in rheumatoid arthritis, which can serve as diagnostic and prognostic marker.

Interpretation

Significant titer > 1;80 In RA titers are often 1:640 to 1:51120 and sometimes<1:3,20,000 Titers in conditions other than RA are usually <1:80; Gives useful objective evidence of RA but a negative does not rule out RA: Positive in 5-10 percent of healthy population; progressive increase with age in < 25-30 percent of persons older than 70 years;

Positive or negative tests should be made precise with the following supplementary tests:
· Measuring rheumatoid factor (RF) level in the blood
· Measuring erythrocyte sedimentation rate (ESR) of the blood to measure inflammation in the body
· Measuring C-reactive protein (CRP)–an indicator of active inflammation in the blood
· White blood cell count
· X-rays of affected joints

6. Mantoux’s Test/Tuberculin Skin Test

Introduction

Mantoux's Test for TB is based on the fact that MTB infection induces sensitivity to certain antigens of the bacillus. These antigens are contained in the tuberculin preparation called purified protein Derivative (PPD) The individual infected with TB usually turns positive 3-8 weeks after infection when immune response is developed.

Indications

Persons with signs (eg. Radiographic abnormality) or symptoms (eg. Cough. hemoptysis, weight loss ) suggestive of current T.B. Recent contacts with known tuberculosis cases or persons with HIV infection.

Interpretation of PPD results

1. An Induration of 5 mm is positive in; persons with HIV infection or HIV risk factors; Close contacts of patients with active TB; Persons who have fibrotic changes or chest X-ray film ( appearance of healed TB)

2. An induration of 10 mm is positive in all persons who do not meet any of above criteria but who have the following risks for TB;

High risk groups ; IV durg users known to be seronegative; chronic renal failure with dialysis; DM immunosuppressive therapy, malignancies; Children<4 years of age.

High prevalence groups ; persons born in high TB prevalence countries
3. An induration of 15 mm is classified as positive in persons who don's meet any of the above criteria.

Factors causing decreased ability to respond to Tuberculin

Infection; viral, bacterial and fungal, Live virus vaccination (measles, mumps, polio); Metacolic derangements (CRF): Nutritional factors (severe protein depletion); disease of lymphoid organs (Hodgkin's disease, CLL, Sarcoidosis): Drugs ( immuno suppressants)

7. HIV Antibody by ELISA

Introduction

HIV Antibodies appear in 1-4 months and rarely >12 months after infection; found in 95 percent of patients within 6 months.

Indications and Inferences

· ELISA is the recommended screening test for HIV which has specificity and sensitivity of >99percent. False positive and false negative rate is < 2 percent.
· When ELISA test is positive or uncertain repeat positive ELISA result must be confirmed using western blot test or IFA which is more specific bit less sensitive than ELISA.
· When ELISA is negative, western blot test is usually not done and this blood may be used for transfusion if donor does not belong to a high-risk group.
· if ELISA is positive and western blot is negative, the patient's blood should not be used for transfusion, although diagnosis of AIDS is not confirmed.
· If EIA is positive and western blot and/or IFA results are equivocal, HIV infection status is unknown and western blot test should be repeated in 4-6 months: this person should not donate blood.
· Western Blot test is considered the gold standard for confirmation of HIV tests.
· PCR for HIV is used to confirm indeterminate Western Blot Test results or negative results for persons suspected of infection.

False positive results may be due to

Administration of influenza vaccine upto 3 monthes back or any immunoglobulin within 6 weeks; presence of HLA-DR antibodies, RF. in autoimmune disorders. multiple myeloma. hemodialysis. alcoholic hepatitis.

8. Hepatitis Markers

(I) Hepatitis A : Serological markers

Anti HAV lgM appears simultaneously as symptoms in 99 percent of cases peaks within first month, become non detectable in 12 months (usually 6 months ) presence confirms diagnosis of recent acute infection. Anti HAV total is predominantly lgG except immediately after acute HAV infection when it is mostly lgM and lgA almost always positive at onset of acute hepatitis and IgG is usually detectable for life.

(II) Hepatitis B; Serological markers

Indications

Differential diagnosis of hepatitis; Screening of blood and organ donors; Determination of immune status for possible vaccination

Hepatitis B surface antigen (HBsAg) is the earliest and most reliable indicator of HBV infection, appears in 2-41 days (as early as 14 days) Usually disappears in 12-20 weeks after onset of symptoms or laboratory abnormalities in 90 percent of the cases. Persistence > 6 months defines carrier state. May also be present in chronic infection.

Is never detected in some patients and diagnosis is based on presence of HBclgM. Transfusion of blood containing HBsAg causes hepatitis or appearance of HBsAg in blood > 70 percent of recipients. Screening out of blood donors
with HBsAg is found in : Chronic persistent hepatitis (50%) Chronic active hepatitis (25%), Cirrhosis (3%) Patients undergoing multiple transfusion (3.0%), Durg addicts (4.2%) Blood donor population (<0.1%)

Antibody to HBsAg (anti HBsAg); presence of antibody (without detectable HBsAg) indicates recovery from HBV infections absence of infectivity and immunity from future HBV infection.

Hepatitis B envelope Antigen (HBeAg) : Indicates highly infectious state. Appears within I week after HBsAg. Usually present for 3-6 weeks .Is a marker of active HBV replication in liver persistence >20 weeks suggests progression to carrier state and possible chronic hepatitis

Antibody to HBe (Anti HBe); Appears after HBeAg disappears and remains detectable for years. Indicates decreasing infectivity suggest good prognosis for resolution of acute infection.

Antibody to Hepatitis B core Antigen (Anti HBc lgM) ; It is the earliest specific antibody: usually occurs 2 weeks after HBsAg. May be the only serological marker present after HBsAg have subsided but before these antibodies have appeared (serologic gap or window ) it is the serological test that can differentiate recent and remote infections as it is the only test unique to recent infections.

Anti HBc IgG appears before anti HBclgM disappears and lasts indefinitely.

(III) Hepatitis C

Antibody to Hepatitis C Virus (anti HCV)

Indications

Screening of populations with prevalence, including blood donors.
Initial evacuation of patients with liver disease. including those with increased serum ALT.
Anti HCV presence indicates past or present infection but doesn't differentiate between acute chronic and resolved infection.

(IV) Hepatitis D(Delta)

Hepatitis D is due to transmissible virus that depends on HBV for expresssion and replication. It may be found for 7-14 days in serum during acute infection Delta agent can be an important cause of acute chronic hepatitis. The course depends on the presence of HBV Infection.

(V) Hepatitis E

Antibody to Hepatitis E can be detected by fluorescent antibody blocking assay and by western blot; not commercially available.

ENDOCRINOLOGY

I. Thyroid Function Tests (TFT)

Thyroid function tests are indicated in certain populations such as newborns those with strong family history of thyroid disease. elderly women, 4-8 weeks postpartum, patients with autoimmune disease (e.g. Addison's disease, type I diabetes mellitus) TFT's may be useful in women aged > 40years with nonspecific complaints Various TFT'S are:

Thyroid stimulating hormone (TSH)

Introduction

Measurement of basal serum TSH concentration is useful in the diagnosis of both advanced and subclinical hypothyroidism, where structural or functional abnormalities that impair hormone synthesis is compensated for by hypersecretion of TSH in thyrotoxic states, the serum TSH concentrations almost always low or undetectable.
T3, T4, TSH

Used in combination as a Thyroid function test for initial diagnosis of Thyroid disorder.

Generally recommended in:
Abnormal weight loss or gain.

Typical symptoms of hypothyroidism tiredness, lethargy, intolerance to cold constipation, bradycardia, increased menstruation.

In children if they fail to grow normally. If ability to comprehend is less and mental growth is found to be insufficient. If puberty is delayed.

Symptoms of hyperthyroidism tiredness, hot, tachycardia, short of breath, increased appetite but lose weight, muscular atrophy, characteristic features of protruding, staring eyes and enlarged thyroid gland.

Infertility

Reference range -
TSH: - 0.28 - 6.82 uIU /ml
Neonatal TSH:- 2.0-20 uIU/ml

Total Thyroxine (T4)

Introduction

Total Thyroxine includes both the free fraction and bound fraction of Thyroxine hormones.

Normal Range
T4 Male: - 4.4 - 10.8 ug/dl
T4 Female- 4.8-11.6 ug/dl
Neonates: - T4:- 8-23 ug /dl

>Increased
Hyperthyroidism; Pregnancy; Drugs (e.g. estrogens, OC'S, d-thyroxine, amiodarone, heroin, amphetamines); Others include euthyroid sick syndrome, first 2 months of life increase in Thyroxine Binding Globulin (TBG).

Hypothyroidism: Hypoproteinemia (e.g. nephrosis, cirrhosis); Drugs (e.g. Phenytoin, T3, ACTH, Steroids); Euthyroid sick syndrome and decrease TBG.

Normal Levels may be found in in Hyperthyroid patients with thryrotoxicosis; Decreased biniding capacity due to hyporproteinemia or ingestion of certain drugs (e.g. Phenytoin. Salicylates)

Triiodothyronine (T3)

Introduction
Diagnosing T3 Thyrotoxicosis or cases in which FT4 is normal in presence of symptoms of hyperthyroidism: Evaluated cases in which FT4 borderline elevated or in cases where overlooking diagnosis of hyperthyrodism is very undesirable ( eg. Unexplained atrial fibrillation):Monitoring the course of hyperthyroidism or T4 replacement therapy or predicting outcome of antithyroid drug therapy in Grave's disease.

Normal Range T3: -
0.50- 2.00ng/ml

Increased in

Hperthyroidism and thyrotoxicosis ( Good biochemical indicator of severity of thyrotoxicity and also early indication of hyperthyroidism but TSH is better.): Pregnancy ; Druges( eg. clofibrate, estrogens.OC'S).

Decreased in

Hypothyroidism; Nephrosis or other cases of hypoproteninemia.

SUMMARY TABLE

CLINICAL DISORDERS
T3
T4
TSH
Primary hypothyroidism
L
L
VH
Congenital hypothyroidism Cretinism
L
L
VH
Child hypothyroidism-Juvenile myxedema
L
L
VH
Hashimoto's
L
L
H
Iodine deficiency-Endemic Goiter
L\N
L\N
L
Secondary hypothyroidism
L\N
L\N
L
Subclinical hypothyroidism
L\N
L\N
VH
Graves disease
H
H
VL\UN
Euthyroid ophthalmic Graves disease
N
N
L\N
Thyrotoxicosis (Due to intake)
H
H
H
Thyroiditis
L\H\N
L\H\N
H
Toxic multinoduler goiter
H
H
N
Toxic adenoma
H
H
L
T3-toxiosis
H\N
H\N
L\N
T4-Toxicosis
H\N
H\N
L\N
Pituitary tumor
H\N
H\N
H
Thyroid Carcinoma
H
H
L\N
Jod-Basedow
L
L
L
Sub-acute Thyroiditis
H
H
L
Postpartum Thyroiditis Syndrome
H
H
L\N
Non toxic goiter
H\N
H\N
N
Non thyroid illness
H\L\N
H\L\N
N
Thyroid replacement therapy (Normal)
H
H
L\N
Thyroid replacement therapy (excess dose)
H
H
H
Endogenous antibodies to thyroid hormones
H
H
N
Familial Dysalbuminic Hyperthyroxinemia
H
H
N

H - High, L-Low, VH-Very High, VL-Very Low, N- Normal, UN- Undetectable

FERRITIN
This test is done to evaluate whether abnormally low or high amounts of iron are present in the body.
Iron is normally stored in body tissues. Low levels of ferritin suggest that iron stores in the body are low. Too little iron can cause iron-deficiency anemia.
Iron deficiency anemia is the most common form of anemia.

Moderately high levels of ferritin may suggest that inflammation (caused by infection or some other disease) is present somewhere in the body.
Very high levels of ferritin suggest that the body is storing too much iron (a condition called hemochromatosis).

Female 20-50 yrs. - 22-112 ng/ml

" 60-90 yrs. - 13-651 ng/ml

Male 20-50 yrs. - 34-310 ng/ml

" 60-90 yrs. - 4-665 ng/ml
Umbilical
Cord blood 30-276 ng/ml

Infant 0.5 months - 90-628 ng/ml

" 1 months - 144-399 ng/ml

" 2 months - 87-430 ng/ml

" 4 months - 37-223 ng/ml

" 6 months - 19-142 ng/ml

" 9 months - 14-103 ng/ml

" 12 months - 1-99 ng/ml

Children up to 15 yrs. - 7-142 ng/ml

INFERTILITY
Infertility means not being able to conceive after a year of well timed and unprotected intercourse. About a third of time, infertility can be attributed to the men, In another one third of cases, it is because of women and the final third by a both partners or no cause is found. In order to get pregnant, there are various treatments to various problems, Diagnosis of the cause of infertility is very important.
Since the majority of women become pregnant within one year of having unprotected intercourse, most couples are advised to try to conceive this long before beginning fertility testing. For women those with known medical problems that might affect fertility (such as Polycystic ovarian disease or pituitary tumors), or women who are attempting to get pregnant through artificial insemination, earlier testing may be appropriate.
It is important that both partners be tested initially to carefully assess the extent of the fertility problems.
Infertility Evaluation - for Women
Infertility Evaluation - for Men
Basic Infertility Evaluation for Women
The basic infertility evaluation for women includes a history and a physical examination. Additional testing to further refine the diagnosis is often completed as well.
The evaluation typically starts with a careful history of each woman's symptoms and previous experiences. This can include:
A review of the pattern of menstrual cycle bleeding to help determine if ovulation is occurring and if other problems such as diminished reserve (aging) of the ovary or uterine defects (fibroids or polyps) are present.
Collection of information which might suggest an anatomic problem with the tubes, such as questions about past history of sexually transmitted disease, painful periods or intercourse, and/or a previous abdominal surgery.
Questions about prior surgery to the cervix or freezing for abnormal pap smears.
A general review of systems to ascertain symptoms suggestive of other endocrine abnormalities, which might be contributing to infertility.
A careful social history to evaluate for any environmental exposures or social habits (such as smoking, drinking alcohol, or drug usage) which could contribute to the infertility.
Next a physical examination is performed to evaluate the pelvic organs and assess potential hormonal problems.
Finally, additional hormonal testing or ultrasounds may be required to evaluate ovulation. An x-ray of the uterus and tubes (hysterosalpingogram or HSG test) may be completed to assess uterine or tubal status and surgical procedures such as a laparoscopy or hysteroscopy may be indicated to evaluate the structure of the uterus or fallopian tubes in more detail.

Basic Infertility Evaluation for Men
Approximately 45% of couples will have associated male infertility. It is for this reason that evaluation and treatment of the male is critical to a thorough comprehensive program for the infertile couple. A combined approach is essential to ensure successful evaluation and management.
An initial male fertility work-up includes a history, physical examination, general hormone tests and one or more semen analyses, which measure semen volume as well as sperm number, motility and quality of motion.
The initial evaluation typically begins with a series of questions that may include:
A review of past medical history, prior surgeries and medications used.
A discussion of family history of infertility or birth defects.
A careful review of social history and occupational hazards to evaluate potential exposure to hazardous substances that could impact fertility.
Next a thorough physical examination is performed to evaluate the pelvic organs - the penis, testes, prostate, and scrotum.

Semen Analysis

Indications

. Infertility studies
. Absence of sperms to confirm vasectomy
. DNA test to confirm rape assailant

Preference ranges

Volume >2ml
pH 7.2-8.0
Color Translucent, gray-white, or opalescent
Liquefaction <30mins
Viability >65%
Motility >50% viable sperm with forward progression Progressive motility
Sperm density (count) >20 million\mL
Morphology >30% normal forms
Total motile functional >40 million

RBC 0-5\HPF
WBC 0-5\HPF
Crystals None
Clumping None
Mixed antiglobulin Negative
reaction
Bovine cervical mucus >30mm
penetration
Cultures for bacteria, No pathogens
Chlamyis
Antisperm antibodies Negative

Interpretation

. Sterile males usually show
Volume of <3ml
only a count < 5 milion sperms ml seems to reduce chance of pregnacny
< 25% motility
. Abnormal motility or morphology can occur with normal sperm count but are usually seen with decreased counts.
. Inflammatory cells may indicate infection of GI tract.

Laboratory tests, such as a urinalysis, semen evaluation, and hormonal assessment are also conducted.
Hormonal tests evaluate levels of testosterone and FSH to determine the overall balance of the hormonal system and specific state of sperm production. Serum LH and prolactin are other hormonal tests that may be done if initial testing indicates the need for them.
When a diagnosis is not obvious after the initial evaluation, further testing may be required. One or more of the following tests may be recommended:
Seminal Fructose Test to identify if fructose is being added properly to the semen by the seminal vesicles.
Post-ejaculate Urinalysis to determine if obstruction or retrograde ejaculation exists.
Semen Leukocyte Analysis to identity if there are white blood cells in the semen.
Kruger and WHO Morphology to examine sperm shape and features more closely.
Anti-sperm Antibodies Test to identify the presence of antibodies that may contribute to infertility.
Ultrasound to detect varicoceles (varicose veins) or duct obstructions in the prostate, scrotum, seminal vesicles and ejaculatory ducts.
Testicular biopsy to determine if sperm production is impaired or a blockage exists

After the diagnostic evaluation is completed, a therapeutic route is chosen, which may involve medical or endocrinologic treatment, surgical correction, or a decision to manipulate or process the sperm, which already exists to achieve a pregnancy.

REPRODUTIVE HORMONE TEST

Following serum hormonal assays can be done to evaluate various aspects of reproductive function, both in males and females.

Leutinizing Hormone ( LH)
Follicule Stimulating Hormone( FSH),
Estradiol
Progestrone,
Prolactin,
hCG

Introduction

LH and FSH are pituitary gonadotropins that are major hormones regulating follicular development in ovaries.

Fertility hormones
LH AND FSH

LH and FSH are pituitary hormones and mainly used in diagnosing secondary reproductive dysfunction i.e. because of Hypothalamus or pituitary dysfunction.

Generally recommended in:

Irregular menstrual Hypogonadism in male and female (failure of gonads to develop properly) When a female complains of masculinising features or a male complains of feminine features Infertility cases
IVF centers assisted conception
Monitor LH, FSH levels after LHRH stimulation
LH/FSH ratio is a useful parameter in diagnosis of PCO
FSH is a good indicator in menopause
In children where they seem to grow faster than their age or otherwise precocious and delayed puberty
- FSH, LH on 3rd day of periods - thyroid profile T3, T4, TSH - serum prolactin - testosterone , 17OH progesterone

LH:
Men- 0.7-7.4Miu/ml
Women
Follicular phase - 0.5-10.5mIU/ml
Midcycle- 18.4-61.2mIU/ml
Luteal- 0.5-10.5 mIU/ml
menupausal - 8.2-40.8mIU/ml

FSH:

Men/1.0-14.0mIU/ml

Women
Follicular phase- 3.0-12.0mIU/ml
Mid cycle- 8.0-22.0 mIU/ml
Leutal phase- 2.0-12.0 mIU/ml
Postmenopausal- 35.0-151.0 mIU/ml

SUMMARY TABLE

CLINICAL DISORDERS
LH
FSH

Primary Hypogonadism
H
H
Infertility
L
L
Amenorrhea
L
L
Menopause
H
H
Precocious puberty
H
H
Complete testicular
feminization
H
H
Hirsuitism and Virilization
L
L
Kallmann's Syndrome
L
L
Klinefilter's Syndrome
H
H
Turner's Syndrome
H
H
Corpus luteum deficiency
L
L
Ovarian Tumor
L
L
Polycystic Ovarian disease
H
H
Failure of pituitary or hypothalamus
L
L
Primary Testicular Disease
H
H
Secondary Testicular Disease
L
L
Testosterone receptor defects
H/N
H/N
Isolated germinal cell disease
H/N
H/N
Early pregnancy
H
N

H High, L-Low, VL- Very Low, VH -Very High, N -Normal, SH -slightly high,
SL- slightly low.

Indications

Differential diagnosis of gonadal disorders; Diagnosis and management of infertility.

>Increased in

Primary hypogonadism ( anorchia, testicular failure, menopause), Gonadotropin secreting piuitary tumors,Complete testicular feminization syndrome; Precocius puberty(secondary to CNS lesion or idiopathic); Luteal phase of mestrual cycle.

Secondary hypogonadism ( kallmann's syndrome,Pitutary LH or FSH deficiency Gonadotropin deficiency).

Estradiol

Introduction
Estradiol (17β-estradiol) (also oestradiol) is a sex hormone. Labelled the "female" hormone but also present in males, it represents the major estrogen in humans. Estradiol has not only a critical impact on reproductive and sexual functioning, but also affects other organs including bone structure.
At menopause, estrogen concentrations in the body fall to low levels. This decrease is often accompanied by vascular instability (hot flashes and night sweats), a rise in incidence of heart disease, and an increasing rate of bone loss (osteoporosis). Estrogen replacement for alleviation of menopausal symptoms or to prophylax against heart disease and osteoporosis has become very common.
Estradiol levels are used to assess fertility, amenorrhea and precocious puberty in girls. Measurement of estrogen levels is also useful to monitor and titrate replacement therapy especially when the endpoints are long term health (reduction in heart disease and osteoporosis) rather than the immediate relief of symptoms.

Normal Range

Children Adults Males Premenopausal Postmenopausal
adult females females
<60 pg/ml <40 pg/ml follicular phase 30-120 pg/ml <60pg/ml
ovulatory phase 150-400 pg/ml
lutenic phase 70-200 pg/ml

Indications

For differential diagnosis of : Primary or secondary hypofunction of ovarian or hCG producing tumors; Gynecomastia.

>Increased in

Granulosa cell or Theca cell tumor of ovary,; pregnancy; Secondary to stimulation by hCG-producing tumors teratoma, teratocarcinoma); Gynecomastia.

Primary hypofunction of ovary ( Autoimmune oophoritis, resistant- ovary syndrom, toxic, infection, tumor, mechanical, genetic, menopausal): Secondary hypofunction of ovary ( disorders of hypothalamic- pituitary axis).

PROLACTIN
Proclatin, a gonadotropin produced by anterior pituitary is essential for lactation. But hyperprolactinemia is common cause of amenorrhea and infertility in females.

Mainly used to detect infertility since high levels of Prolactin inhibit steroidogenesis and inhibit LH, FSH production.

Generally recommended in:
Diagnosis of hyperprolactinemia and monitoring the effectiveness of treatment
When a male complains of impotence, decreased libido.
Female complains of irregular menstrual cycle, Amenorrhea.
Pituitary tumors (microadenoma or macroadenoma)
Used alone or with LH and FSH for detecting pituitary dysfunction.

CLINICAL DISORDERS
PROLACTIN
Prolactinoma (pituitary tumor)
H
Polycystic Ovarian Disease (PCO)
H
Hirsutism and Virilization
L
Hypothyroidism
L
Infertility
L
Amenorrhea
L
Chronic Renal Failure
H

Men- 1.8-17.0 ng\ml
Women
Adult- 1.2-19.5 ng\ml
Postmenopausal- 1.5-18.5 ng\ml

Progesterone

Introduction

Progesterone is the principal hormone secreted by corpus luteum and is responsible for progestational effects that maintain pregnancy throughout soon after conception

Normal Range

Male

Female

0-1 yr.
Post puberty
follicular phase
Luteal phase

0.87-3.37 ng/ml
0.2-1.3 ng/ml
-
-

0.87-3.37 ng/ml
Increasing values
0.2-1.3 ng/ml
1.0-4.5 ng/ml

Indications

Elevated serum progesteron levels is used as an indicator of ovulation; For differential diagnosis of ovarian and adrenal tumors.

Increased in

Luteal phase of menstrual cycle; Luteal cysts of ovary; Ovarian arrhenoblastoma and adrenal tumors.

Decreased in

Amenorrhea; Threatened abortion; Fetal death, toxemia of pregnancy; Gonad agenesis.

Testosterone

Introduction

Testosterone is mainly produced by leydig cells of testis in; small amounts produced by ovaries and afdrenals in females.

Normal Levels: Total Free
Males 300-1200 ng/dl 9-30 ng/dl
females 20-8 ng/dl 0.3-1.9 ng/L

Indications

Evalution of gonadal homonal function

Increased in

Adrenal virilizing tumor causing premature puberty in boys masculinization in women; Idiopathic hirsutism - in conclusive ; Stein leventhal syndrome , ovarial strom hyperthecosis.

Decreased in

( Men) Primary and secondary hypogonadism ( eg. orchiectomy);Testicular Feminization; Klinefelter's syndrom; Estrogen therapy.

BETA HUMAN CHORIONIC GONADOTROPHIN (B-hCG)

B-hCG is most commonly used in the diagnosis of pregnancy. For qualitative determination detection limit is generally high up to 25 mlU\ml. However b-hCG is also used as a quantitative marker in problematic pregnancy cases, as a tumor market and in Down's syndrome, This requires that the assay method (ELISA, CLIA, RIA) used have a low detection limit i.e. a very high sensitivity for correct diagnosis.

Generally recommended in:

Detection of early pregnancy: Commonest use of b-hCG utilization assays with detection limit up to 25mlU\ml permits detection pregnancy at approx 7 days post implantation lore sensitive assays can detect as early as 1-2 days after implantation

Threatened abortions hCG levels are generally low compared to normal pregnancy. A serial measurement of hCG is recommended
Generally hCG doubles in 2 days in early pregnancy. Failure to increase over a period of 4 days or more is an unfavorable sign.
Ectopic pregnancy, positive in all cases of ectopic pregnancy. If hCG is negative rule out pregnancy. If hCG is positive, but shows no sign of pregnancy on ultrasound, there is still a possibility of ectopic pregnancy.

Down's syndrome hCG is elevated.

Late pregnancy Low levels in placental insufficiency and high levels in pre-eclampsia.

Confirming diagnosis and management of tumors also used in staging of cancer. Monitoring treatment.

1st week - 10-30mIU\ml
2nd week - 30-100mIU\ml
3rd week - 100-1000 mIU\ml
4th week - 1000-10000 mIU\ml
2nd &3rd month - 30000-100000 mIU\ml
2nd Trimester - 10000-30000 mIU\ml
3rd Trimester - 5000-15000 mIU\ml

*Choriocarcinoma hCG elevated

*Male germ cell tumors-hCG elevated

*Some cases of cancer of breast, lung and small intestine elevated hCG

DIABETIC MARKERS

INSULIN

Children<12yrs <10mIU\ml
Adult(normal) 0.7- 9.0mIu\ml
Diabetic(TypeII) 0.7- 25mIu\ml

The most important reason for measuring the blood insulin level is the diagnosis of documented acute or chronic (fasting) hypoglycemia (low blood sugar) .
Also, insulin levels measured while fasting can give information about the body's sensitivity to insulin. High insulin, even with normal blood sugar, may indicate that the pancreas is working harder that normal to get the blood sugar level down. This situation is usually caused by the body being resistant to insulin's effect a condition called "insulin resistance syndrome: or: metabolic syndrome". It is a very common feature of obesity and of hormonal problems such as polycystic ovary syndrome. It also helps determine when a type 2 diabetic might need to start taking insulin injections to supplement oral medications.

Insulin may be used, often along with glucose and C-peptide levels to help diagnose insulinomas (islet-cell tumor).

C-PEPTIDE

Adult normal (0.7-1.9ng\ml)

A C-peptide test measures the level of peptide (an inactive amino acid) that is released in the body in amounts equal to insulin. The level of C-peptide in the blood can indicate how much insulin the pancreas is producing.
C-peptide testing can be done when diabetes has been newly diagnosed and it is not clear whether type 1 diabetes or type 2 diabetes is present. A person whose pancreas is unable to produce any insulin (type 1 diabetes) usually has a decreased level of insulin and c\peptide. A person with type 2 diabetes has a normal or increased level of C-peptide.
C-peptide testing can also help determine the cause of low blood sugar (hypoglycemia). There are several causes of hypoglycemia, including the excessive use of medication to treat diabetes or the presence of a noncancerous growth (tumor) in the pancreas called an insulinoma, Because man-made (synthetic) insulin does not contain C-peptide, a person with a low blood sugar level from the inappropriate use of insulin will have a low C-peptide level. An insulinoma causes the pancreas to release excessive amounts of insulin, which causes blood sugar levels to decrease (hypoglycemia).

Microalbum
Microalbuminuria occurs when a malfunctioning kidney leaks small amounts of albumin into the urine. The level of albumin protein produced by Microalbuminuria cannot be authentically detected by urine dipstick methods. A microalbumin urine test determines the presence of the albumin in urine. In a properly functioning body, albumin is not normally present in urine because it is filtered from the bloodstream by the kidneys.
Microalbuminuria is diagnosed either on 24-hour urine collections (20 to 200 µg/min) or, more commonly, if elevated concentrations (30 to 300mg/L) on at least two occasions.[1]. Albumin levels above these values is called "macroalbuminuria"
To compensate for the variable possible urine concentration on spot-check samples, it is more typical to compare the amount of albumin in the sample against its concentration of creatinine. This is termed the Albumin/creatinine ratio (ACR) and microalbuminuria is defined as ACR ≥2.5 mg/mmol (male) or ≥3.5 mg/mmol(female).[2]

TEST: MICROALBUMIN/CREATININE RATIO, URINE

SPECIMEN: First morning random urine or 24 hour collection. Refrigerate during collection. Urine in boric acid tubes is acceptable. Avoid gross RBC contamination.

MINIMUM SAMPLE: 6 mL, prefer 40 mL.

TRANSPORT: 40 mL aliquot from well-mixed urine. Store and
Stable refrigerated 2 weeks.

REFERENCE VALUES: (mg microalbumin/gm Creatinine)
<30 Normal, Repeat yearly
30-300 increased risk for diabetic nephropathy.
Two of three A/C ratios in this range indicate microalbuminuria and diabetic nephropathy.
>300 Two of three A/C ratios in this range confirms overt clinical nephropathy.

CLINICAL SIGNIFICANCE:
An indicator of subclinical cardiovascular disease
marker of vascular endothelial dysfunction
an important prognostic marker for kidney disease
in diabetes mellitus
in hypertension
increasing microalbuminuria level during the first 48 hours after admission to an intensive care unit predicts elevated risk for acute respiratory failure , multiple organ failure , and overall mortality
Detection is important so that therapeutic intervention may prevent or delay end-stage renal disease.

1. Urine Examination

General Examination

General examination of Urine includes;

1. Quantity/Volume

Adults; 600-2500ml/24 hrs

Infants; premature 1-3 ml/kg/hr
full term 1560ml/24 hrs
2-8 wks 250-400ml/24hrs
1 year 500-600ml/24 hrs

Anuria (Excretion<100ml/24hrs);

Due to bilateral complete urinary tract obstruction, acute corneal necrosis necrotising GN . certain causes of acute tubular necrosis.

Acute oliguria(Excretion<400ml/24hrs or approximately 20 ml/hr; 15-20ml /kg/24hrs in children);

2. Colour:
Normal colour of urine is clear to yellow (urochrome pigment). Abnormal colour can be due to following causes.

Colour
Causes
Red colour
Hemoglobin, erythrocytes, myoglobin, polyphyrin, fuscin, aniline dye, beets
Red purple
Porphyrins
Red brown
Erythrocytes, hemogloblin on standing, methemoglobin, myoglobin
Brown black;
Methemoglobin, homogentisic acid, melanin
Blue green
Indicoms, pseudomonas infection, chlorophyll
Yellow Brown
Bilirubin-biliverdin
Yellow
Acriflavin
Yellow orange
Concentrated urine, urine, urobilin in excess or bilirubin
Yellow green
Bilirubin and biliverdin

Color of urine can also change because of commonly used drugs like Chlorzoxazone, phenothiazine, rifampicin, phenindone, Aminopyrine, doxorubicin, ibuprofen, phenytoin, phenacetin, metroniadazole, levodopa, chloroquine, iron sorbitex etc.

3. Appearance

Milky Many neutrophils (pyuria), lipiduria, chyluria, milky emulsified paraffin

Cloudy Phosphates, carbonates, urates, uric acid, leukocytes, red cells,

Smoky Bacteria, yeast, spermatozoa, prostratic fluid, mucin, mucus threads, calculi,.

Colorless Very dilute urine

4.Specific Gravity

Normal
1.003-1.030

Increased in
Proteinuria, Glycosuria, dehydration,adrenal insufficiency, and hepatic disease, CHF, mannitol, diuretics, antibiotics, detergent, increase in temperature

Decreased in
Diabetes insipidus, pyelonephiritis, glomerulonephiritis.

Isothenuric urine
No variability between several specimens from patient and specific gravity that is fixed at about 1.010. Isothenuric urine indicates severe renal damage.

5. pH
Normal urinary pH ranges from 4.6-8

*Acidic urine
Produced by diet high in meat protein and cranberries
Mild respiratory acidosis of sleep, pharmacologic agents like ammonium chloride, methionine, methanamine mandelate; Patient with metabolic or respiratory acidosis diabetic ketoacidosis

*Alkaline urine
Produced by diet rich in citrus fruits and vegetables pharmacologic agents like agents like sodium bicarbonate and potassium citrate and acetazolamide; In metabolic or respiratory alkalosis.

Chemical Examination

1. Proteins

Normal excretion

0.01gm/24hrs Qualitative;0

Heavy proteinuria ; (>4g/day)

Causes

Nephritic syndrome, acute rapidly progessive and chronic glomerulonephritis, DM lupus erythematosus, CHF, consstrictive pericarditis, renal vein thrombosis, Malari, malignant hyppertensi;on, toxemia of pregnancy, heavy metals, drugs .
(pencillamine, neoplasia, sicckle cell disease.)

Moderate proteinuria; (1.0-4.0g/day)

Moderate proteinuria may be found in nephrosclerosis multiple myeloma and toxic nephropathies.

Minimal proteinuria: (<1.0g/day)

In chronic pyelonephritis, intermittent and in relatively inactive phases of glomerulonephritis, nephrosclerosis, polycystic disease and renal tubular diseases and chronic interstitial nephritis.

2. Glucose:

Normal, excretion: <0.03gm/24hrs

Glycosuria with hyperglycemia occurs in

Diabetes mellitus
Other causes are: acromegaly, Cushing's syndrome, hytperadrenocorticism, functioning u or b cell pancreatic tumours, hyperthyroidism, pheochromocytoma, brain tumour or hemorrhage, burns, infections and fractures, liver disease, obesity, starvation and glycogen storage. Diseases and pregnancy.

Glycosuria without hyperglycemia occurs in
Renal tubular dysfunction, galactosemia, cystirosis, lead poisoning and myeloma.

3. Reducing substances

Used for diabetes mellitus screening (not a primary screening modality). Reducing substances are present in urine due to:
Glycosuria [hyperglycemia, renal, heriditary, neonatal lactosuria during lactation].
Non sugar reducing substances (eg. Ascorbic acid, glucuronic acid, homogentisic acid, salicylates) .

4. Ketones

Casuses of Ketonuria

Diabetic Ketonuria is a warning sign of impending coma. More common in Type I DM
Non diabetic Ketonuria: Common in infants and in children in conditions like acute febrile illness, vomiting or diarrhoea or hyperemesis of pregnancy cachexia, severe exercise, low carbohydrate diet, lactic acidosis [in shock, renal failure, liver disease, infections, drugs]

5. Bilirubin

Normal excretion

0.02mg/dL

Causes of bilirubinuria

Acute viral hepatitis, durg induced cholestasis, acute alcoholic hepatitis. hepatotoxic drugs, congenital hyperbilirubinemias [Dubin johnson Rotors type].

6. Urobilinogen

Normal excretion

0.5-2.5mg/24hrs.

Increases urobilinogen excretion in viral hepatitis. drugs. toxins. some cases of cirrhosis, CHF and cholangitis .

7. Occult Blood

occult blood in urine is used for screening and diagnosis of GU tract disorders and for screening excess anticoagulation.

Normal range

<3 RBCs/HPF

Interpretation

· Red coloured urine > 50,00,000 RBCs
· Blood clots; Bladder origin
· Small stingy clots; upper UT origin
· RBC casts or HB casts; glomerular origin
· Gross hematuria ; Origin in urethra distal to urogenital diaphragm
· Pyuria or WBC casts; Inflammation and infection of GU tract
· Persistent intermittent hematuria should always be evaluated; one cpisode of microscopic hematuria may be due to viral infection, mild trauma, exercise etc.

Leucocytes

Normal range; 5-30/mL

Neutrophils are predominant type of leukocytes that appear in urine.

Pyuria ; > 5 leukocytes/ HPF (principally neutrophils) is termed as pyuria and indicates presence of infection or inflamation in urinary tract.

Eosinophils

Normally not seen in urine > 1% eosinophils among leukocytes is considered significant.

Causes

Tubulointerstital disease, allergic intestinal nephritis, UTI, renal transplant rejections.

Epithelial cells

Few squamous and transitional epithelial cells are normally present in urine.
Abnormal epithelial cells
Interpretation
Large sheets of transistional all
Transistional cell cacinoma
Renal tubulur epithelial cells
Tubular damage
Collecting duct epithlial cells
Renal transplant rejection, acute tubular necrosis. ischemic injuries, acute glumerulonephritis.

CASTS

Normally few casts are present in urine.

Increased cast formation occurs with lower pH, increased ionic concentration, stasis or obstruction of nephron by cells or debris, large amount of proteins entering tubules [albumin, Bence Jones protein, hemoglobin, myoglobin, Tamm-Horsfall protein]. Casts can be formed from large numbers of cellular elements in urine called cellular casts, or there can be crystal casts containing urates, calcium oxalate, pigmented casts like Hemoglobin, Homosiderin, myoglobin present in renal disorders and diseases.

Crystals

Crystals in urine are of limited clinical significance, proper identification is essential so as not to miss the relatively few abnormal crystals that are associated with various pathological conditions.

Bacteria
>100,000 organisms\mL is significant
. Commonly entering organisms are cause of UTI
Acid fast bacilli may be seen in sediment which must be confirmed by culture

Fungi

Yeast (Most commonly Candida) are causative organism in UTI (especially in DM) are also nonpathogenic contaminants from skin, female genital tract or air.

Parasites

. Parasites and parasitic ova may be seen in urine sediments as a result of fever or vaginal contamination. when found, repeat examination on fresh, clean voided urine specimen should be done.

. Schistosoma haematobium ova are directly shed in urine in schistosomiasis.

II. Urine Pregnancy Test (by Latex agglutination)

Introduction

Antobodies to HCG can easily be induced in rabbits and antiserum so produced can be used to detect the presence of HCG in urine of pregnant women by an agglutination reaction between HCG absorbed on to latex particles and HCG antiserum.

Indications

For detection of pregnancy: It becomes positive 4 days after the missed period.
Also positive in Ectopic pregnancy, Hydatiform mole and choriocarcinoma.

False negative results may occur with dilute urine missed abortion, dead fetus syndrome or ectopic pregnancy

False positive results may occur due to bacterial contamination, protien or blood in urine.

III. Stool Examination

Normal Values

Bulk 100-200gm
Water upto 75%
Total osmolality 200-250mosm
pH 7-7.5(acidic with high lactose diet)
Nitrogen <2.5gm\day
Patassium 5-20meq\kg
Sodium 10-20meq\kg
Magnesium <200meq\kg
Coproporphyrin 400-100mg\24hrs
Trypsin 20-95 U\gm
Uro bilinogen 50-300mg\24hrs

Microscopic Examination

.RBCS absent, few WBC's present (increased with GI tract inflammation). Epithelial cells present (increased with GI tract irritation): absence in mecomium of newborn may aid in diagnosis of intestinal obstruction

. Crystal of calcium oxalate, fatty acid and triple phosphate commonly present
. Hematoidin crystal found after GI tract hemorrhage, charcoal-Leyden crystals in parasitic infection
. Some undigested vegetable fibers, muscle fibres and neutral fat globules present normally.

Color changes

Normal: Brown

Clay color (gray white): biliary obstruction, Alkaline antacids

Tarry: >100mL of blood in upper GI tract

Red: blood in large intestine, undigested beets tomatoes and phenazopyridine, phenothalkin, tetracycline

Black: blood, Bismuth salts, char coal, Iron salts

Silver: combination of jaundice and blood cancer of ampulla of water

Various colours: depending on diet and drug use

Occult blood

Indication

Screening for asymptomatic ulcerated lesions of AGI tract, especially carcinoma of colon and large adenomas.

Interpretation

Normal blood loss\day: <2mL\day or 2mgHb\gm of stool
50% of colon cancers shed enough blood produce a positive test
Adenomas<2cm, less likely to bleed. Upper GI tract bleeding is less likely than lower GI tract bleeding to cause positive test.

V. CSF Examination

Normal values

Apperarance
Clear, colorless: no clot

Total cell count

Adults, children: 0-6\cumm
Infants : <19\cumm
Neonates : <30\cumm

Glucose
45-80mg\dL (20mg\dL less than blood level)
Ventricular fluid 5-10mg\dL higher than lumbar fluid.

Total protein

Cistemal : 15-25 mg\dL
Ventricular : 5-15mg d\L
Lumbar : 15-45mg.dL (3 mths.-60yrs.)
15-60mg\dL (>60yrs)

Chloride : 120-130meq\L (20mEq\L above serum values)
Sodium : 142-150mEq\L
Potassium : 2.2-3.3mEq\L
pH : 7.35-7.4
Billrubin : 0
Urea nitrogen : 5-25mg\dL

CSF, Abnormal

Gross Appearance
Viscus CSF: in metastatic mucinous adenocarcinoma (e.g. colon),Large number of cryptococci, severe meningeal infection.

Turbid CSF: due to increased WBC's (>200\cumm) or RBC's (>400\cu.mm)or presence of bacteria (>105\mL) or other microorganisms.

Bloody CSF: due to bilirubin>6mg\dL

Faint yellow: due to proteins> 100mg\dL

Cytology

WBC's may be corrected for presence of blood (e.g. Traumatic tap, subarchnoid hemorrhage) by subtracting IWBC for each 700RBC's \cumm of CSF if CBC is normal.

CSF WBC count (>3000\cumm) with predominantly PMNS strongly suggests bacterial cause.

When <1000\cumm>50% lymphocytes or monoueclear cells which appear in later stages of meningitis.

Neutrophilic leukocytes are found in bacterial infections (e.g. Nocardia, Actinomyces, Brucella), Fungal infections, chemical meningitis.

Lymphocyte cells found in bacterial infections mycobacterium tuberuiosts, brucella, treponema pallidoin, fungla infections parasitic infections (e.g.Toxoplasma, eystecerocosis). viral infections (mumps, HTLV. echovirus), brain abseess.

Eosinophilis are found in lymphoma, angiostongyloids cysticerocosis.

CSF CHEMISTRY

CSF Glucose: Lags behind blood glucose by 1hr.Decreased by utilization of bacteria (pyogenes or tuberele bacilli), WBC's or cancer cells in CSF.
CSF glucose rarely decreases in viral meningitis or parameningeal infections lymphocytic choriomeningitis encephalitis due to mumps or HSV.

CSF Proteins
. Serum protein levels must be normal to interpret any CSF protien . . values and should therefore always be measured currently.
. Usually> 150mg\dL m bacterial meningitis with S pneumeoniae.
. >100mg\dL distinguishes bacterial transpetic meningits.
. >100mg\dL suggest subarchnold block with complete spinal block lower level cord tumor, the higher protein concentration.
. Rarely >200mg\4L in viral meningitis
. Mild to moderate elevation in myxedema, uremia, Cushing’s syndrome connective tissue disorders.

CSF chloride: reflects only blood chloride levels, but in tuberculosis meningitits a decrease of 25% may exceed the serum chloride decrease because of dehydration and electrolyte loss

CSF lactate: may differentiate bacterial form viral meningitis.
If 3mmol\L (normal range), viral meningitis most likely
If > 4.2 mmol\L (normal range), viral meningits most likely.
If > 4.2 mmol\L. bacterial (including TB or fungal most likely).
CSF glutamine: > 32mg\dL is associated with hepatic encephalopathy.

VI. Pleural Effusion

Normal values

Specific Gravity : 1.010/1.026

Total Proeins

Albumin 0.3-4.1gm/dL
Globulin 50-70%
Fibrinogen 30-45%
PH 6.8-7.6
Effusion can be classified as transudate or exudate.

Transudate : has low protein (<3gm/dL) LD and all count. And found in CHF Cirrhosis with asates (Pleural effusion in 5%Cases) Nephrotic syndrome. Early atelactasis, pulmonary embolism. superior venacava obstuction. hypoalburrinemia, peritoneal dilysis, Early mediastinal malignancy. myxedema constructive pericarditis.

Exudates ; has high protein (<3g/dL), LD and cell count. ANd found in :

· pneumonia, malignancy, pulmonary embolism, GI conditions (eg. pancreatitis and abdominal surgery. wihch cause 90% of all exudates)
· Infection (25%of cases): Bacterial pneumonia para pneumonic effusion (empyema). TB, Abscess, viral. mycoplasmal, rickettsial. parastic, fungal.
· Pulmonary emcolism infarction. neoplasm. trauma (hemothorax, chylothorax, empyema associated with rupture of diaphragm )
· Immunologic(Rheumatoid pleurisy, SLE. of the collagen vascular diseases )

Gross Appearance

Clear strawcoloured fluid is typical of transudate

Cloudy, opaque appearance indicates more of all components

Bloody fluid suggests malignancy, pulmonary infarct, trauma, uremia, asbetstosis, pleural endometrosis

Chylors fluid is due to trauma, obstruction of duct

(eg in lymphoma, metastatic carcinoma)

Pseudochylous in chronic inflammatory conditions (eg rheumatoid pleurisy, TB)

White fluid suggets chylomorax, cholesterol effusion or empyema

Black fluid suggests Aspergillus higher infection

Greenish fluid suggests bilirpleural fistula

Purulent fluid suggests infection

Anchovy (dark red brown color is amebiasis. old blood

Anchovy paste in ruptured amebic liver abscess.

Turbid and greenish yellow fluid is classical for rheumatoid effusion

Turbidity may be due to lipids increased WBC's

Debris in fluid suggests rheumatoid pleurisy, very viscus (clear or bloody) is characteristic of mesothehoma.

Glucose

Same concentration as serum in transudate while may decrease in exudate because of WBC's and bacteria.

pH

Low pH (7.3) always means exudate especially empyema, malignancy, rhuematoid pleurisy. TB SLE, oesophageal rupture.

Amylase: Increased amylase in acute pancreatic and pancreatic pseudocyst.

Cell count

· Total WBC count is almost never diagnostic
· > 10.000/ cumm indicates inflammation (pancreatitis, pulmonary infarct)
· > 50.000/cumm is typical only in parapneumonic effusion
· Chronic exudates (eg malignancy and TB) < 5000/cu.mm
· Transudates are usually < 1000/cu.mm
· 5000-6000 RBC / cu.mm give red color to effusion

Cytology

Positive in 60% malignancy on first tap 80% by third tap. Therfore should repeat taps with cytological examination if cancer is suspected.

ASCITES
Accumulation of ascitic fluid is caused most often by cirrhosis of the liver and is the most common complication of that disease. However, it also may be due to cancer, heart failure, tuberculosis, pancreatic disease, dialysis, or other causes (1). The development of ascites heralds a progressive deterioration in a patient's clinical condition, and only 50% of affected patients survive 2 years after onset

Chronic liver disease : to differentiate ascites due to malignancy from that due to chronic liver disease

· Almost always > 1.1 in cirrhosis. alcoholic hepatitis. massive liver metastates, fulminant hepatic failure, portal vein thrombosis, cardiac ascites, myxedema.
· < 1.1gm/dL in 90% cases of peritoneal carcinomatosis ( most common cause) or TM. pancreatic or biliary ascites nephrotic syndrome, bowel infarctions.
* Ascitic fluid to serum albumin ratio < 0.5 in cirrhosis and total WBC usually <300/cumm and PMN is usually <25%
* Cardiac ascites is associated with blood ascitic fluid gradient >1.1 gm/dK as compared to malignnat ascites with <1.1 gm/dL.

Infected Ascitic fluid

· WBC>250 cumm and neutrophils > 50% are presumptive of bacterial peritonitis
· pH <> 0.10: both these findings are virtually diagnostic of bacterial peritonitis and absence of the above findings virtually excludes bacterial peritonitis
· Ascitic fluid LD is markedly increased
· Gram Stain positive in 2.5% cases and culture has 85% sensitivity
· Total protein <1gm/dL high risk for spontaneous bacterial peritonitis

Pancreatic disease

Ascitic fluid amylase greater than serum amylase

Malignant ascites

Increased fluid cholesterol (>45mg/dL) and fibronectin (>10mg/dL). Positive cytology has sensitivity of 70% and specificity of 100%

Diagnosis of ascites due to portal hypertension is established by measurement of the serum-ascites albumin gradient (SAAG).

Bone Marrow Aspiration

Indications

Bone marrow aspiration is done when following diagnosis are suspected:

Aplastic anemia agranulocytosis: Leukemia. lymphomas, Megaloblastic anacmias Lipid storage disease: Metastatic cancer: Multiple myeloma: Waldenstrom's macrogloculinemia; Idiopathic thrombocytopenic Purpura (ITP): Hyperaplenism : Irondeficiency anaemia; Indicated for diagnosis and for posttreatment follow-up of acute leukemia and cytopenia.

Fine needle aspiration cytology

FNA cytology has become an integral part of the initial diagnosis and management of patients. This simple technique has gained wide acceptance since it offers a high degree of accuracy, lending itself to outpatient diagnosis, and thus making considerable savings in the cost of hospitalization

Radiology Basics
All information contained in this section was primarily obtained from Radiology 101: The Basics and Fundamentals of Imaging by William Erkonen .
Plain radiographs
Basics
Lower density structures absorb less of the administered x-ray beam.
So,
--Air and fat are BLACK.
--Bone, metal, and calcium are WHITE.
--All other tissues are varying shades of gray, depending on the density of the structure.
Common views: PA, AP, Lateral, Oblique views. This indicates the direction of the beam, e.g. in a PA view the beam is directed from posterior to anterior. Portable views thus have to usually be AP.
Contrast Media
Contrast Media is used to distinguish between soft tissue or organ densities. High density contrast agents are used (usually injected IV) to enhance the target areas, increasing their density and making them appear more white. IV contrast agents are used for fistulograms, draining sinuses, hysterosalpingograms, and other such studies.
Barium studies are indicated for GI pathology visualization. The high-density contrast medium can be ingested orally, or administered via enema or intestinal tube. When air is introduced with barium, it is called a double-contrast study .
These studies are better tolerated and less invasive than endoscopy, and are usually the first-step in evaluating bowel pathology.
Gastrograffin is a water-soluble iodinated compound and can be ingested as a solution. It can be employed in the same manner as barium, but give poorer contrast because it is less dense. Indications include suspected perforation(where barium may be contraindicated) and gallbladder stones/tumors(oral cholecystogram). This compound is hypertonic, and can be toxic if leaked into the tracheobronchial tree.
IV iodinated compounds are used in angiography, CT, and for urinary tract visualization(e.g. excretory urogram or Intravenous Pyelogram, IVP).

Computed Tomography (CT)
Q. Who was ultimately responsible for the advent of CT technology?
A. The Beatles!!
Believe it or not, a fair amount of credit must go to the best band ever for being primary financial support for Electric Musical Instruments, Ltd, the engineers of which developed the basis of CT technology in the 1970s.
Basics:
CT images are produced by a combination of x-rays, computers, and detectors. The x-ray tube in the housing of the CT scanner emits pencil-thin beams of x-rays through each anatomic slice of the patient. The x-rays strike detectors(instead of film) and subsequently is converted through computer software into cross-sectional images.
Indications:
3D correlation of plain films, trauma, intracranial hemorrhage, abdominal injury, foreign body detection, primary and metastatic tumors of the liver, kidney, brain, lung, and bone, lymphomas, as well as staging of neoplasms(nodal spread).

Magnetic Resonance Imaging (MRI)
Basics:
MRI involves the imaging of protons, specifically hydrogen. There are many hydrogen atoms in fat, so fat is very bright. Bone has little H+ in it, so it is black.
T1 —fat is white, gray soft tissue detail quality really high, resolution really great; good for viewing anatomy.
T2 —water is white, soft-tissue has less contrast, fat is more gray. This is good for viewing pathology, in which necrosis, effusion, hemorrhage, or other process which has more water will light up with better contrast to normal tissues.
Indications :
MRI detects small changes in soft tissues, with better contrast than CT, so it is good for rotator cuff tears, meniscal tears, and other soft tissue imaging.
Gadolinum creates improved contrast between tissues (esp. on T1); good for tumors, infections, and acute stroke; safer than iodinated contrast.
MRA shows blood flow to be bright, as opposed to black on normal MR imaging. This is an ideal way to visualize flow in cerebral and carotid vessels, using gradient echo pulse sequence. The advantages of this technique include that it is non-invasive, requires no catheters, needles, or iodinated contrast agents.

Ultrasound (US)
Basics:
Short bursts of high-frequency sound waves (1-10MHz) are intermittently broadcast by a transducer. The analog sound waves reflected back are digitized and converted into and image.
Solid tissues —more homogeneous and WHITE.
Ex: Liver, spleen, kidney (not calyces).
Cystic structures —Hypoechoic, BLACK.
Ex: Cysts (renal, liver, etc.), gallbladder, bladder.
Pros : Safe, fast, inexpensive, very portable, multiple plane imaging possible, including obliques.
Cons : Requires technical skill/operator dependent, not good for lung and bone.
Indications:
Fetal monitoring/imaging, GB/kidney pathology, ovarian, endometrial pathology, testicular pathology, breast imaging for cysts.

Nuclear Medicine (NM)
Basics:
Small amounts of radionuclides are administered, tagged to a variety of compounds that can selectively be taken up by a particular organ to be studied. The radioactive emissions from the administered compounds are then detected and recorded by a special camera with a sodium iodide crystal, and an image is made.
Indications :

Interventional Radiology (IR)
Examples of procedures—angiography, thrombolysis, balloon angioplasty, PICC placement, Percutaneous Biliary drainage/stenting, IVC filter placement, and more.

Index

Activated partial Thromboplastin Time Estogens, Total 42
(aPTT), 12 Folicle stimulating Hormone (FSH), 41
AFB microscopy,31 Globulin,20
Albumin,20 Glucose, Blood, 13
Alkaline phosphatase, Glucose Tolerance Test
(GTT,) Oral, 13
Alanine Aminotransferase(ALT) HAV lgmAb,37
Anti HBC lgm,38 HBeAg,38.
Anti HBe,38 HBsAg,38
Antistreptococcal antibody titres HCV Antibodies,39
(ASOT),33 HDAg,HDV-RNA,39
Ascities,57 Hemoglobin(Hb),4
Aspartate Aminotransferase(AST) Hepatitis markers,37
Bilirubin (Total &Direct),19 HEV Antibodies, 39
Bleeding time (BT), 10 HIV (Antibody by ELISA),36
Blood Culture, 30 Lactate Dehydrogenase Ld, 25
Bone Marrow Aspiration, 58 Leukocyte Count, Differential,6
Calcium, 28 Leukocyte Count Tota 6
Cardiac profile, 23 Leutinizing Hormone (LH)
Chloride, 29 Lipid profile, 14
Cholesterol, HDL 15 Liver profile, 18
Cholesterol, LDL,15 Mantoux' Test, 35
Cholesterol, Total, 15 Mean Concentration Hemoglobin
Clotting Time(CT), 11 (MCH), 5
Complete Blood Count (CBC), 4 Mean Corpuscular Hemoglocin
C-Reactive Protein (CRP), 34 Concentration (MCHC) 5
Creatine Kinase (CK) 23 Mean Corpuscular volume (MCV) 4
Creatine Kinase -MB (CK-MB)24 Peripheral Smear (PS) 8
Creatinine, 17 Phosphate, Inorganic, 27
CSF Examination,53 Platelet Count, 8
Erytrocyte Sedimentation Rate(ESR) 9 Plueral Effusion, 55

Index

Pottasium, 28 Triiodothyronine (T3), 41
Progesterone, 43 Total Thyroxine (T4), 40
Prolactin, 43 Total Thyroxine (T4) Free
Proteins Serum, Total, 19 Testosterone, 44
Prothombin Time (PT), 12 Thyroid Function Tests (TFT), 40
Renal profile, 16 Triglycerides, 16
Reproductive Function Tests, 41 Thyroid stimulating hormone (TSH)40
Reticulocyte Count (RC), 9 Tuberculin skin Test, 35
Rheumatoid Factor (RF), 34 Urea Nitrogen/ urea- Blood, 17
Semen analysis, 52 Uric Acid, 18
Serology and immunology, 32 Urine Examination, 45
Serum Eectrolytes, 26 Urine pregnancy Test, 51
Sodium, 28 Venereal Disease Research
Stool, 51 Laboratory(VDRL), 32
Sugar, Blood, 14 WIDAL, 33

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