In solid organ transplantation, antibody-mediated rejection (AMR) is mediated by donor-specific antibodies (DSA) targeting which antigens on the endothelium?
- A ABO blood group antigens
- B HLA class I and II antigens ✓
- C Minor histocompatibility antigens
- D MICA (MHC class I chain-related molecule A)
Correct answer: B. HLA class I and II antigens
Explanation
Antibody-mediated rejection is caused by preformed or de novo donor-specific antibodies (DSAs) directed against donor HLA class I (expressed on all nucleated cells and endothelium) and HLA class II (expressed on endothelium, dendritic cells, macrophages). DSAs activate complement (C4d deposition in peritubular capillaries is a histological marker) and directly injure endothelium causing microvascular inflammation. ABO incompatibility causes hyperacute rejection; MICA DSAs are an additional non-HLA pathway.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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