A 50-year-old woman presents with fatigue, pallor, and jaundice. Peripheral smear shows spherocytes, direct Coombs test is positive for IgG, and warm-reactive autoantibodies are identified. The primary site of red blood cell destruction in this condition is the:
- A Liver (Kupffer cells)
- B Blood vessels (intravascular hemolysis)
- C Spleen (macrophages) ✓
- D Bone marrow (ineffective erythropoiesis)
Correct answer: C. Spleen (macrophages)
Explanation
Warm autoimmune hemolytic anemia involves IgG autoantibodies (usually against Rh antigens) coating RBCs at 37°B. Splenic macrophages have Fc receptors that bind IgG and partially phagocytose the membrane, producing spherocytes and extravascular hemolysis. Intravascular hemolysis (option B) occurs in complement-mediated cold agglutinin disease or PNH.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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