Coomb’s + ve Hemolytic Anaemia is seen in all except –
First, Coomb's test detects antibodies or complement on the surface of red blood cells. Positive results can be seen in autoimmune hemolytic anemias (AIHA), like warm or cold types. Also, certain infections like EBV, HIV, or malaria can cause it. Drug-induced hemolysis is another cause, such as penicillin or cephalosporins. Paroxysmal cold hemoglobinuria (PCH) is another one.
So the question is asking for the exception. The options might include conditions that don't typically cause a positive Coomb's test. For example, hereditary spherocytosis is a Coomb's negative hemolytic anemia because it's an intrinsic RBC membrane defect. Similarly, G6PD deficiency is Coomb's negative as it's an enzymopathy leading to oxidative damage. Sickle cell anemia is also Coomb's negative. Thalassemia is another Coomb's negative condition.
If the options include these, then the correct answer would be the one that's Coomb's negative. Let's say the options are A. Hereditary spherocytosis, B. G6PD deficiency, C. Sickle cell anemia, D. Warm AIHA. Then the answer is D because Warm AIHA is Coomb's positive. Wait, no, the question is "all except," so the correct answer would be the one that's NOT Coomb's positive. So if one of the options is a Coomb's negative anemia, that's the correct answer.
Wait, the question is phrased as "Coomb's +ve Hemolytic Anaemia is seen in all except." So the correct answer is the one where the anemia is not Coomb's positive. For example, if the options include hereditary spherocytosis, that's the answer. Let me confirm that hereditary spherocytosis is indeed Coomb's negative. Yes, because it's an intrinsic RBC membrane defect, not due to external antibodies. So in that case, the correct answer would be the option that lists hereditary spherocytosis.
So the structure would be: Core concept is about Coomb's test in hemolytic anemia. The correct answer is hereditary spherocytosis because it's Coomb's negative. The other options are Coomb's positive. The clinical pearl is to remember that Coomb's positive is due to antibodies, while Coomb's negative is intrinsic defects or mechanical causes.
**Core Concept**
Coomb's test detects IgG or C3d on red blood cells, indicating immune-mediated hemolysis. Positive results are seen in autoimmune hemolytic anemia (AIHA), drug-induced hemolysis, infections (e.g., EBV), and paroxysmal cold hemoglobinuria (PCH). **Coomb's-negative hemolytic anemias** arise from intrinsic RBC defects (e.g., hereditary spherocytosis) or mechanical damage (e.g., microangiopathic hemolytic anemia).
**Why the Correct Answer