A 35-year-old man undergoes cadaveric renal transplant. On day 3 post-transplant, he develops sudden oliguria, graft tenderness, and fever. Biopsy shows dense neutrophilic infiltration of glomeruli and vessels with fibrinoid necrosis but no significant lymphocytic infiltrate. DSA (donor-specific antibodies) are detected at high titer. This rejection is BEST classified as:
- A Hyperacute rejection mediated by pre-formed anti-HLA antibodies causing complement activation
- B Acute antibody-mediated rejection (ABMR) with microvascular injury driven by de novo or pre-formed DSA ✓
- C Acute T-cell mediated (cellular) rejection with tubulitis and interstitial lymphocytic infiltrate
- D Chronic allograft nephropathy with transplant glomerulopathy
Explanation
The presentation on day 3 post-transplant with oliguria, neutrophilic glomerulitis, peritubular capillaritis, fibrinoid vascular necrosis, and high-titer DSA is characteristic of acute antibody-mediated rejection (ABMR). DSA bind donor endothelial HLA antigens, activate complement (C4d deposition in peritubular capillaries is a hallmark), and recruit neutrophils via Fc receptors. Hyperacute rejection (minutes to hours intraoperatively) occurs when pre-formed antibodies are present before transplant — now rare with crossmatch testing. Cellular rejection shows CD4+/CD8+ lymphocytes in tubules (tubulitis) and interstitium, without the neutrophilic vasculitis.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.