Antibody-mediated rejection of renal allograft presenting as hemorrhagic necrosis mimicking adenovirus nephropathy: a case report and literature review

Abstract Background Antibody-mediated rejection (AMR) can occasionally present with hemorrhagic necrosis and histopathological findings resembling adenovirus nephropathy (ADVN), making differentiation between these conditions challenging. In addition, coexistence of rejection and adenovirus (ADV) infection has been reported, further complicating the diagnosis. Herein, we report a case of AMR with hemorrhagic necrosis requiring differentiation from ADVN. Case presentation A 71-year-old man on chronic hemodialysis for end-stage renal disease due to benign prostatic hyperplasia underwent an ABO-incompatible living-donor kidney transplant from his wife. Post-transplant, he showed no evidence of de novo donor-specific antibodies or rejection on protocol biopsies. Twenty-two months after transplantation, he presented with gross hematuria, graft swelling, and a rapid rise in serum creatinine (1.4 → 7.9 mg/dL). Steroid pulse therapy was initiated after an allograft biopsy for suspected rejection. Pathological findings made it difficult to distinguish between AMR and ADVN. As anti-human leukocyte antigen antibodies turned positive, the patient was treated for AMR with rituximab, double filtration plasmapheresis, and intravenous immunoglobulin. Although gross hematuria resolved, graft function did not improve. ADV was not detected by polymerase chain reaction (PCR) testing of urine or blood, nor by virological examination of the biopsy specimen. A repeat biopsy 2 weeks later revealed AMR accompanied by hemorrhagic necrosis. Despite outpatient follow-up, graft function gradually declined, and dialysis was resumed. Conclusions We encountered a case of AMR of renal allograft showing hemorrhagic necrosis mimicking ADVN. Because these conditions can coexist, comprehensive assessment—including clinical course and virological, pathological, and immunological findings—is essential for accurate diagnosis and appropriate management.