When anti–coagulated blood is allowed to stand undisturbed for some time, the red blood cells start to settle down. The rate at which red blood cells settle down is known as the Erythrocyte sedimentation rate.
It is done by three methods:
- Westergren’s method.
- Wintrobe’s method.
- Micro–sedimentation (Landau) method.
|Westergren’s method||0–15 mm. after 1st hour||0–20 mm. after 1 hour|
|Wintrobe’s method||0–9 mm.after 1st hour||0–20 mm. after 1 hour|
|Landau method||0–5 mm after 1st hour||0–8 mm after 1 hour|
- ESR is increased in infections like tuberculosis, rheumatic fever, myeloma, Kala Azar, other chronic infections.
- ESR is greater in women than men due to difference in PCV (Packed Cell Volume).
- In certain anemias, ESR gradually increases after the third month and returns to normal after three to four weeks after delivery.
- ESR is low in infants and gradually increases as the child grows to puberty.
- The determination of ESR is useful in checking the progress of disease. The changes of ESR are not diagnostically of any specific disease.
Normal range: 2,50,000 – 5,00,000/cu mm (ml).
Many times prolonged bleeding and poor clot formation is due to Thrombocytopenia (decreased platelet count).
It is also found in aplastic anemia, megaloblastic anemia, hypersplenism and acute leukemia.
Thrombocytosis (increased platelet count) is found in polycythemia vera, following splenectomy and in chronic myelogenous leukemia.
Splenectomy – is the surgical removal of the spleen.
Hypersplenism – in this spleen is enlarged.
Meaning of other terms is given in routine blood tests.
- Adults – 0.2 to 2%.
- Infants – 2 to 6%.
- Reticulocyte is a precursor of Red Blood Cells (RBCs). Reticulocyte count is reflection or erythropoetic activity (red blood cell forming activity) of the bone marrow.
- Increase in the number of reticulocyte indicates increased activity of the bone marrow, in hemolytic anemia or acute blood loss. It is known as reticulocytosis.
- Absence or low count of reticulocytes indicates bone marrow suppression in aplastic anemia.
- Increased eosinophil count indicates certain leukemia, allergic reactions, parasitic infections and brucellosis.
- Decreased eosinophil count indicates Cushing’s Syndrome (increase in adrenal function).
In blood coagulation, thrombin which is formed from prothrombin acts on soluble fibrinogen in the presence of Ca++ ions to form numerous insoluble fibrin threads. These threads criss–cross with one another. Erythrocytes (RBC) and Leucocytes (WBC) are entangled in their interstices and clots are formed.
The routine coagulation test is carried out for:
- Patients who have to undergo a major surgery.
- Patients who have a history of spontaneous bleeding after trauma or surgery.
- Bleeding time.
- Clotting time.
- Clot retraction and lysis time.
- Prothrombin time.
- Plasma recalcification time.
- Partial thromboplastin time.
- Activated partial thromboplastin time.
- Thrombin time.
- Fibrinogen determination.
- Protamine sulphate test.
|Bleeding time||1 – 5 minutes|
|Blood Clotting time||4 – 5 minutes|
|Clot reaction & lysis time||Of 50% of clot retraction occurs at the end of 1 hr at 37 C, it is abnormal.
Normal lysis time is 72 hrs.
|Prothrombin Time||14 (I) 2 seconds|
|Plasma recalcification time (RT)||Platelet rich plasma: 100 – 150 seconds
Platelet poor plasma: 135 – 240 seconds
|Partial thromboplastin time (PTT)||60 to 80 seconds|
|Activated partial thromboplastin time (APTT)||35 to 40 seconds|
|Thrombin Time||15 to 20 seconds|
|Fibrinogen||200 to 400 mg/dl|
|Protamine Sulphate test||if – to ++ is normal|
- Sickle Cell Anemia Screening.
- Determination of Fetal Hemoglobin.
- Determination of Osmotic Fragility of Red Blood Cells.
- Determination of Lupus Erythematosus (LE) Cell.
- Determination of Heinz Bodies.
- Determination of Blood Parasites.
- Determination of Glucose: 6 – Phosphate Dehydrogenase (46–PD).
- Determination of Iron and Total Iron Binding Capacity (TIBC) in Serum.
- Determination of Electrophoretic Fractionation of Hemoglobin.
- Microscopic Examination of Bone Marrow and Detection of Iron.
- Different tests to be performed in Different Bleeding Disorders.
- Normal blood does not have sickle cells.
- Clinical findings in S C Anemia.
- Normocytic, normochromic red cells.
- Presence of nucleated RBC, sickle cells and Howell–Jolly bodies.
- Increased reticulocytes.
- Increased platelets.
- Decrease in osmotic fragility of RBC.
- Hemoglobin electrophoresis shows particular hemoglobin.
- Positive sickle cell test.
High level of fetal hemoglobin (HBF) is found in B–thalassemia major patient. Mild but significant rise is observed in (HBF) in B–thalassemia trait, sickle cell disease and in other congenital or acquired hematological conditions. Various percentage of HBF observed.
|B – thalassemia major||10–98%|
|Sickle cell trait||Normal|
|Sickle cell anemia||1–20%|
Determination of Osmotic Fragility of Red Blood Cells
This is useful in determining hereditary spherocytosis, thalassemia and sick cell anemia. Here the Median Corpuscular Fragility (MCF) is determined.
|Normal||0.45% or little lower.|
|Sickle Cell Anemia and Thalassemia.||0.35% to 0.4%.|
Determination of Lupus Erythematosus (LE) Cell
Lupus Erythematosus is a disorder of collagen. Collagen is a fibrous, insoluble protein in connective tissue. If the test shows the presence of LE cells, it indicates the disorder.
Determination of Heinz Bodies
It is useful in detecting metabolic defects caused due to the deficiency of G–6 – PD or glutathione. The test is positive even when a patient is undergoing therapy with drugs such as anti–malarials and suphonamides.
Detection of Blood Parasites
Given in Routine Hematological (Blood) Tests.
Determination of Glucose: 6 – Phosphate Dehydrogenase (G6 – PD)
Glucose – 6 – phosphate dehydrogenase deficiency is hereditary disorder. Presence of this enzyme is required in red blood cells to protect hemoglobin from oxidation. Absence of this enzyme is harmless unless red blood cells are exposed to antipyretics, anti–malarial drugs and sulphonamides.
|Normal||30 – 60 minutes.|
|4 – 6 PD deficient||140 minutes to 24 hours.|
|4 – 6 carriers||90 minutes to several hours.|
Determination of Iron and Total Iron Binding Capacity (TIBC) in Serum
Serum Iron: 60 – 150 mg/dl
Serum TIBC: 270 – 380 mg/dl
- Decrease in the serum iron level is due to chronic blood loss or nephrosis (any disorder of the kidney that is caused by any degenerative process other than infections).
- Increase in the serum iron level is due to hemolytic anemia, lead poisoning, pyridoxine deficiency, pernicious anemia and necrotic hepatitis (Necrosis means death of a small area of tissue within an organ).
- Decrease in serum TIBC is found in cirrhosis (a type of permanent and progressive liver damage), hemochromatosis and nephrosis.
- Increase in serum TIBC is found in different states of chronic iron deficiency and nephrosis.
Hemoglobin is a conjugated protein when it is subjected to an electrical field, the different proteins depending upon their speeds towards the anode (at pH 8.9). Normal and abnormal hemoglobin have different velocities. This helps in identifying congenital disorders of hemoglobin.
This test is conducted in various anemias like aplastic, megaloblastic, sideroblastic. It is also done in acute leukemias, multiple myeloma (malignant tumor of the bone marrow) and diseases of the reticuloendothelial system (network of very thin tissue that lines the lymphatic and blood vessels, the heart and various other body cavities). In iron deficiency anemias, iron is very low but in sideroblastic anemia it is increased.
Different Tests to be Performed in Different Bleeding Disorders
|Bleeding Disorder||Laboratory Test|
|I) Vascular defect platelet defect.||Bleeding time.|
|II) Coagulation factor deficiency.||Clotting time.
Plasma recalcification time.
Activated partial thromboplastin time test (APTT).
|III) Liver disorder and Vitamin K deficiency.||(Increased) APTT.
(Increased) prothrombin time.
|IV) Hemophilia (Antihemophilic factor ‘A’ [AHF] deficiency).||Clotting time.
|V) Excessive fibrinolysis.||Clot lysis test.
Protamine sulphate test.
|VI) Christmas disease (Plasma thromboplastin component (PTC) or antihemophilic factor ‘B’ or Christmas factor.||Antihemophilic factor ‘B’ assay.|
|VII) Von Willebrand’s disease (vWD). It is combination of vascular defect, platelet defect and antihemophilic factor ‘A’[AHF] deficiency.||(Abnormal)Bleeding time.
(Abnormal) Clotting time.
(Platelet count normal).
|Blood Group||Father||Mother||Possible Group Of Child|
|A||O||A or O|
|A B||B||AB or A or B|
|A||B||A or B or O or AB|
- To check whether an Rh negative woman (married to Rh positive husband) has developed anti Rh antibodies.
- Anti D may be produced in the blood of any Rh negative person by exposure to D antigen by
- Transfusion of Rh positive blood.
- Pregnancy, if the infant is Rh positive (if father is Rh positive).
- Abortion of Rh positive fetus.
- When there is Rh +ve baby in the womb of a Rh –ve woman, to defect hemolytic anemia (described in hemolytic disease of newborn).
- Transfusion reactions.
- Drug induced red cell sensitization.
- Autoimmune hemolytic anemia.
This is useful to defect hemolytic disease of the newborn.
Most important tests performed are:
- Blood grouping and Rh factor.
- Antibody detection by indirect antiglobulin (Coomb’s) test for a typical, incomplete antibodies.
- Hepatitis – B surface antigen.
- AIDS antibodies.
- Syphilis (VDRL) test.
- Malarial parasites.
- The age should be above 18 – 60 years.
- Hemoglobin should not be less than 12.5 g/dl.
- Interval of 16 weeks should be there between two donations.
- Pulse rate should be regular and between to 78 – 100/min.
- Accepted Blood Pressure.
- Systolic: between 90 – 150 mm Hg.
- Diastolic: between 50 – 100 mm Hg.
- Body temperature of donor should be normal.
- Absence of any chronic disease.
- There is a history of viral hepatitis or AIDS.
- There is a history of malaria for the last three years.
- If the patient has received immunization against rabies, mumps, rubella, small pox within two months.
- If the donor has undergone dental surgery within 72 hours.
Blood sugar in the case of a normal person remains fairly constant throughout the day. There is temporary rise in blood sugar levels after food which depends upon the type of food consumed. This increase remains up to two to three hours and then returns to normal. Diminished glucose tolerance is observed when the ability of the body to utilize glucose decreases. The rise in blood sugar or glucose is greater than in a normal person. Also, a return of blood glucose levels to the normal fasting level is slow.
This is observed in 1.
- Diabetes mellitus.
- Hyperactivity of thyroid, pituitary and adrenals.
- Injection of cortisone like hormone.
- Increased secretion of the growth hormone.
- Very severe liver disease.
- Glycogen storage disease of the liver due to the limited capacity of a person to store excess glycogen.
- Severe infection of staphylococcal bacilli or even common cold.
|Time||Fasting||1/2 hour||1 hour||1 1/2 hours||2 hours||2 1/2 hours|
|After taking glucose|
|3 Blood Glucose gm/dl||70||130||145||105||75||80|
|Urine Glucose – Absent throughout the test|
|Normal renal threshold for glucose = 150 – 170 mg/dl.|
Raised renal threshold after ingestion of glucose up to 250 – 300 mg/dl occurs with increasing age and prolonged diabetes mellitus. Lowered renal threshold (130 – 150 gm/dl) is observed in abnormality of tubular re–absorption of glucose.
Extended glucose tolerance curve (instead of two and a half hours goes up to four to five hours) is observed in insulin secreting tumors of the pancreas. It is also observed in Simmond’s disease which causes hypoglycemia (means reduction of sugar or glucose levels. It drops to below 60 mg/dl and affects brain cells).
Normal Range: 4 – 7%.
The ways by which glucose is added to the blood:
- Absorption from the intestine.
- By the breakdown of liver glycogen (glycogen is a starch like carbohydrate) to glucose.
- By gluconeogenesis (a form of glucose from non–carbohydrates).
- By synthesis of fats e.g. triglycerides.
- Conversion to liver glycogen.
- Conversion to muscle glycogen.
- In synthesis of glycoproteins and lactose etc.
- The liver plays an important part by taking glucose from the blood and converting it into glycogen.
- Releasing glucose from glycogen and converting pyruvate to glucose.
- Muscle glycogen does not contribute directly to blood sugar. Glycogenolysis in the muscle produces locate, which is converted into glucose in the liver.
- Kidney plays its part by the re–absorption of glucose when the blood glucose level is below 150 – 170 mg/dl (threshold level).
The following hormones play a part:
A. Insulin: It is secreted by the pancreas. It controls blood sugar in the following ways:
- By increasing transport of glucose across the cell membrane.
- By promoting oxidation of glucose or glycogen to pyruvate and lactate.
- By increasing the formation of glucose from non–carbohydrates.
- By decreasing conversion of glycogen to glucose.
- By inhibiting conversion of protein to glucose and favoring a synthesis of protein from amino acids.
- By promoting the transfer of potassium phosphate and amino acids into the cells.
B. Thyroxine (secreted by the thyroid gland).
C. Glucagon (secreted by alpha cells of the pancreas).
D. Growth hormone (secreted by the pituitary gland).
E. Glucocorticoids (secreted by the adrenal cortex).
F. Epinephrine (secreted by the adrenal medulla).
These hormones increase blood sugar levels by:
- By increasing absorption of glucose from the intestine.
- Decreasing the oxidation of glucose or glycogen to pyruvate and lactate.
- Preventing synthesis of glycogen.
- Stimulating synthesis of glycogen from glucose.
- Stimulating the formation of glucose from non–carbohydrates.
Diabetes Mellitus occurs when blood glucose is too high due to very less insulin or none at all. Sometimes, the pancreas produces normal amounts of insulin but the body needs more than the normal. As a result of this, the body suffers from a lack of energy. People with diabetes often complain of weakness and tiredness.
Characteristics of diabetes mellitus
- Raised fasting blood sugar levels.
- The amount of urine passed is increased often up to 5 to 6 liters of pale urine.
- Due to lack of insulin glucose is not utilized by cells. Energy is obtained through:
- Body proteins.
- In severe cases, more fat is used for energy. The excessive oxidation of fatty acids increases ketone bodies in the blood and there is also an increase in cholesterol synthesis.
- In severe cases, the plasma bicarbonate decreases which results in a fall of blood pH and leads to a loss of sodium ions.
Types of Diabetes
There are two major types of diabetes. Type I and Type II
Type I Diabetes
It is insulin dependent diabetes mellitus (IDDM) or “Juvenile diabetes.” This occurs when beta cells of the pancreas do not function to produce insulin. Patients take supplementary insulin by injections because if taken orally it will get digested, as insulin is a protein in nature. Insulin is either obtained from the pancreas of cattle or pigs, or produced synthetically, using recombinant DNA (deoxyribonucleic acid). This synthetic insulin does not stimulate the formation of antibodies against insulin as the animal insulin may do.
Most often young people get this type of diabetes and the onset is fast. Sometimes, older people also get Type I diabetes which has a slow onset and acts like Type II for a long period.
Type II Diabetes
This is non–insulin dependent diabetes mellitus (NIDDM). The body produces some insulin but the requirement is more. It may be due to reduction in the number of insulin producing beta cells. Due to this, glucose is unable to enter the cells as interaction between insulin and its receptor is less effective. People with this type of diabetes are usually above their ideal weight. Overeating also contributes to it, so diet is primary treatment for this type of diabetes. Generally people above the age of 40 get this type of diabetes, but it may be found in younger people also. About 85% of all people who have diabetes, have Type II diabetes.
Other Types of Diabetes
Some people are not diabetic but may have an increased risk of developing diabetes.
A person both of whose parents are diabetic, or who has an identical twin who develops diabetes, although he/she may not have diabetes initially is considered a prospect for the disease.
Some people have elevated blood glucose levels only in certain times of stress e.g. in pregnancy or during severe infection. They suffer from diabetes but become normal when pregnancy ends or after they recover from the infection.
|Creatine Phospokinase||Male||16 – 110 U/L|
|Female||16 – 94 U/L|
|Creatine Kinase (MB)||Normally, CK–MB activity is less than 5 U/lt. And accounts for less than 3 per cent of the total CPK activity. Myocardial infarction is suggested by CK – MB > 5% of Total CK Activity.|
|Lactate Dehydrogenase||160 – 319 U/lt. (At 30° C)|
|Serum Amylase||Up to 95 U/lt|
|Serum Lipase||20 – 300 U/lt. (At 30° C)|
|Fasting Blood Sugar||80 – 120 mgs/dl|
|Post Prandial Blood Sugar||up to 160 mgs/dl|
|Glycosylated Hemoglobin||< 7%||Normal|
|7 – 8%||Excellent Control|
|8 – 9%||Good Control|
|9 – 10%||Fair Control|
|> 10%||Poor Control|
|Serum Cerruloplasmin||0.20 – 0.55 gms/lt|
|Serum Iron||40 – 130 micrograms/dl|
|Serum Iron Binding Capacity||210 – 385 micrograms/dl|
|Plasma Fibrinogen||200 – 400 mgs/dl|
|Serum Ferritin||Male||20 – 400 ng/ml|
|Female||10 – 130 ng/ml|
|Serum Ammonia||Normal: 11–35 Umol/lt|
|Serum Uric Acid||2 – 7 mgs/dl|
|Serum Acid Phosphatase||Up to 12 U/lt|
|Leptospira IgM||< 10||Negative|
|10 – 20||Low Positive|
|Tuberculosis IgG||Less than 225 Units/ml|
|Tuberculosis IgA||Less than 350 Units/ml|
|Fructosamine||Normal Range||1.6 – 2.6 m mol/l|
|Satisfactory Control||2.6 – 3.2 m mol/l|
|Mediocre Control||3.6 – 3.7 m mol/l|
|Poor Control||3.7 – 4.5 m mol/l|
|Carcinoembryonic Antigen (CEA)||Smokers||Not detectable to 5.2 ng/ml|
|Non–smokers||Not detectable to 3.4 ng/ml|
|Alpha Feto Protein||0 – 20 IU/ml|
|Maternal Serum||Gestational Age|
|15 weeks||8.9 – 61.1|
|16 weeks||10.2 – 56.2|
|17 weeks||15.6 – 59.3|
|18 weeks||16.5 – 79.3|
|19 weeks||18.9 – 86.1|
|20 weeks||18.5 – 103.9|