HAMS Test
Why HAM Test?
CLINICAL INFORMATION
The function of Red Blood Cells (RBCs) is to supply nutrients and oxygen to all the cells in the tissues of our body and to eliminate the end products (or toxic substances) of cellular metabolism including CO2 from each cell and to excrete them from the body, thus keeping our body healthy. Since the RBCs are subjected to mechanical stress as they flow rigorously through various blood vessels (due to its routine physiological action) in the body they undergo enormous wear and tear (so, loses their physical stability i.e the outer membrane integrity of RBCs undergo rupture also loses its elasticity and thus become rigid - unlike new RBCs that are elastic to squeeze through narrow blood capillaries). Hence after around 120 days (normal life span of RBCs) the cell membranes of RBCs get ruptured gets destroyed. The other aged RBCs gets trapped (as they lose their ability to squeeze through physical barriers in spleen sinusoids) by the splenic macrophages and are sequestered. Hemoglobinuria is a condition where haemoglobin (Oxygen transport protein) present within the RBCs is found in abnormally high concentrations in the urine. Causes of hemoglobinuria are hemolytic anaemia, glomerulonephritis, hemolytic uremic syndrome, kidney infection (pyelonephritis) etc. Paroxysmal Nocturnal Hemoglobinuria (PNH) is a rare acquired disease caused by a mutation (of PIG-A gene) in the bone marrow stem cells. This disease condition leads to sudden, irregular episodes of passing dark-coloured urine (in many cases of PNH), especially at night or early in the morning. PIGA gene encodes for the synthesis of an enzyme phosphatidylinositol N-acetylaminyltransferase enzyme (a protein known as phosphatidyl inositol glycan class A, which plays a role of GIP anchor – in the cell surface of RBCs). In normal RBCs these anchor proteins shield from complement (immune) system from being attacked, while in PNH due to mutation in the PIGA gene, it results in the synthesis of defective and/or abnormal protein (anchor protein for RBC’s outer membrane, but is ineffective) and thus it fails to protect the RBCs from the immune complement system and thus undergo early destruction of RBCs resulting in the expulsion of RBC contents such as haemoglobin in the bloodstream, therefore resulting in hemoglobinuria (excretion of haemoglobin in the urine). Complications of PNH lead to undiagnosed bone marrow failure disease resulting in aplastic anaemia. PNH is characterized by hemolytic anaemia, thrombosis (blood clots), impaired bone marrow function and risk of developing leukaemia etc. It is called HAM’S Blood Test since Dr.Ham designed it. It is also called an acidified serum test. This test helps to screen, diagnose PNH and conditions such as Congenital Dys-erythropoietic Anemia (CDA). The principle of HAM’s test is that the RBCs are placed in a mild acid medium and since they are very fragile undergo hemolysis spontaneously. Other additional tests include hemoglobinuria, bone marrow biopsy for histopathology (for confirmation of PNH and also for apastic anaemia due to bone marrow failure).
General Instructions:
Sample Requirement: Specimen – Urine sample. Test Preparation: None.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to the patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centres to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
