Diagnostic Tests

Normal values:

Increase in PCV is due to polycythemia, dehydration, emphysema, and congenital heart disease. Decrease in PCV is due to different types of anemia, hydremia (excessive fluid in the blood which occurs in pregnancy).

Emphysema: It means stretching of body tissue due to the accumulation of gas or air in the tissue or organ. Pulmonary emphysema is a chronic lung disease in which air sacs of the lungs are stretched until the elastic fibers in them are destroyed.
Polycythemia: It is an excess of red blood cells. It may be temporary due to lack of oxygen in the blood. It may be due to heart disease or continued exposure to high altitudes. Also, if may be due to disorder of the bone marrow.
Myeloid leukemia: It is a kind of blood cancer.
Congenital heart disease: It means any heart disorder that is present at birth. Most common is a hole between two ventricles, either narrowing or the wrong position of the aorta (the main artery), or constriction of valves on the left side of the heart with weakness of the heart muscle.
Aplastic anemia: It is a disease of the bone marrow. It produces deficiency of the red blood cells, white blood cells as well as platelets.
Infectious mononucleosis: Also called glandular fever caused by a herpes virus (Ebstein–Barr virus).
Megaloblastic anemia: It is a disease of the bone marrow. Here, immature abnormal red blood cells are found in the blood.
Edema: Swelling of any part of the body due to retention of fluids.
Sub–acute bacterial endocarditis: Endocarditis means inflammation of the endocardium, the inner lining of the heart. When bacteria infects it, then it is called bacterial endocarditis. All types of endocarditis, if untreated are fatal.
Microcytic anemia: A decrease in red blood cells, reduced hemoglobin, PCV, MCV, MCH and MCHC.
Macrocytic anemia: A decrease in red blood cells, reduced, hemoglobin, elevated MCH and MCV with normal MCHC.

Cells

Crystals

Vegetable Matter

Animal Matter

Undigested Ingredients

Other Findings

If a high percentage of gram positive bacteria are present, it indicates intestinal ulceration.

Intestinal Protozoa
There are pathogenic and non–pathogenic protozoa found in stool.

	A.	Non–pathogenic   Entamoeba coli–cysts or vegetative form.   Iodamoeba butschili – cysts.   Endolimax nana – cysts.
	B.	Pathogenic   Entamoeba histolytica – cysts or vegetative form.   Giardia lamblia–cysts.   Balantidium coli–cysts.   Giardia lamblia – vegetative form.

Nematohelminths
They are pathogenic in nature. The different kinds of worms found are:

Platyhelminths
They are pathogenic in nature:

The different kinds of tape worms found are:

Trematodes
They are pathogenic in nature, generally known as fluke:

Determination of Erythrocyte Sedimentation Rate (ESR)
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:

	1.	Westergren’s method.
	2.	Wintrobe’s method.
	3.	Micro–sedimentation (Landau) method.

Normal Range

Method	Male	Female
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.

Determination of Platelet Count
To investigate bleeding disorders, determination of platelets is required. 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.

Determination of Reticulocyte Count
It is done to determine red cell forming activity of the bone marrow.

		Normal Range: 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.

Determination of Absolute Eosinophil Count

		Normal Range: 40 to 440/cu mm (ml).
		Increased eosinophil count indicates certain leukemia, allergic reactions, parasitic infections and brucellosis.
		Decreased eosinophil count indicates Cushing’s Syndrome (increase in adrenal function).

Brucellosis is an infectious disease mainly of cattle, dogs, pigs, goats, and occasionally, of humans. In humans, it is contracted by infected milk and is commonly known as undulant fever or malta fever.

Routine Coagulation Tests
When a blood vessel is damaged, bleeding stops by a process called hemostasis. First, the blood vessel contracts which reduces blood flow. Second, platelets form a plug, and third, clot formation occurs. 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 hemorrhagic disorder tests include:

Special Hematological Tests

Sickle Cell Anemia Screening

Determination of Fetal Hemoglobin
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.

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.

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.

Determination of Iron and Total Iron Binding Capacity (TIBC) in Serum

Normal Values: 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.

Determination of Electrophoretic Fractionation of Hemoglobin
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.

Microscopic Examination of Bone Marrow and Detection of Iron
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

Determination of Possible Blood Group of A Child

Blood Group	Father	Mother	Possible Group Of Child
	A	A	A
	A	O	A or O
	AB	B	AB or A or B
	A	B	A or B or O or AB

Indirect Antiglobulin (coomb’s) Test
This test is performed to detect presence of Rh antibodies or other antibodies in patient’s serum, in the following cases:

	1.	To check whether an Rh negative woman (married to Rh positive husband) has developed anti Rh antibodies.
	2.	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.

Compatibility or Cross’ Matching Test
This is done before transfusion of blood to a patient of the cross–matching as non–compatible blood should never be transfused. Minor cross match results are also important but in an emergency one can use blood with minor incompatibility.

Semi–quantitative determination of Anti–D Antibody Titer
This is useful to defect hemolytic disease of the newborn.

Tests to be Performed and Criteria for Blood Transfusion
Most important tests performed are:

Other tests performed on collected blood are

Criteria accepted for selection of donor

		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.

The donor is rejected if

This is observed in Type 1.

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).

Determination of Glycosylated Hemoglobin
The red blood cells of a normal person and children above six months old contain three genetically determined hemoglobin species HbA – 90%, HbA2 – 2.5% and HbF – 0.5% of total hemoglobin content of RBC. Besides these hemoglobins, other variants of hemoglobin present are HbAla – 1.6%, HbAlb – 0.8% and HbAlc – 4%. They are products of non–enzymatic, post–synthetic transformation of HbA. Their rate of formation depends upon the lifespan of RBCs and its mean hexose concentration. These are collectively measured as HbA – abc or HbAl. HbAl indicates the average blood sugar concentration for an extended time period. It remains unaffected by the short term fluctuations in blood sugar levels. HbAl levels term fluctuations in blood sugar level. HbAl levels reflect carbohydrate imbalance better than fasting glucose concentration or the GTT (Glucose Tolerance Test). The determination of HbAl is a convenient and suitable test as it helps evaluate the adequacy of diabetic control in the prevention of various diabetic complications.
Normal Range: 4 – 7%.

Regulation of Sugar and Types of Diabetes
Concentration of blood sugar (glucose) remains steady up to 100 mg/dl during 24 hours. After partaking of food, it increases up to 140 – 150 mg/dl.

The ways by which glucose is added to the blood:

The ways by which glucose is removed from the blood:

When these processes are performed in the right balance, the blood sugar level remains within the normal limits of about 70 – 110 mg/dl. throughout the day. (Average 100 mg/dl).

		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).

In normal individuals, the blood glucose level does not rise above the 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. Glucose is also regulated by other hormones than insulin but to a lesser extent. These hormones antagonize the action of insulin. They are:
	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:

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.
		Thirst.
		Due to lack of insulin glucose is not utilized by cells. Energy is obtained through Body proteins and Fats. This causes muscular weakness and results in weight loss. Also, the end product of protein is urea which increases above the normal range and causes discomfort.
		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.

The last two conditions may result in diabetic coma.

Types of Diabetes
There are two major types of diabetes. Type I and Type II

Other Types of Diabetes
Some people are not diabetic but may have an increased risk of developing diabetes.

		Pre–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.
		Latent diabetes: 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.

Normal Values

Liver Function Tests – Normal Values

Lipid Profile – Normal Values

Hormonal Assays
Normal Values

Tests done on Automated Chemiluminescent System.