Anti-A Antibody Rebound-Induced Thrombotic Microangiopathy After ABO-Incompatible Kidney Transplantation: A Case...

ABO-incompatible kidney transplantation (ABOi-KT) expands donor availability, but postoperative anti-ABO antibody rebound can lead to rare complications such as thrombotic microangiopathy (TMA), often resulting in graft loss.

A 61-year-old underwent ABOi-KT (A → B) after standard desensitization. Despite achieving pre-transplant anti-A IgG and IgM titers of 1:1, a marked postoperative rebound occurred, with both titers rising to 1:1024 by postoperative day 6, accompanied by TMA and acute rejection manifesting as elevated serum creatinine (sCre) (maximum 8.63 mg/dL). Notably, overt hemolytic markers and thrombocytopenia were absent. Management included intensified plasma exchange, intravenous immunoglobulin, high-dose steroids, and discontinuation of tacrolimus. sCre peaked at 8.63 mg/dL, later stabilizing to ∼5 mg/dL at 1 year without dialysis.

Despite adequate desensitization, anti-A antibody rebound can cause early TMA. Importantly, early recognition and aggressive multimodal treatment can rescue the graft, avoiding the high likelihood of graft loss. This case highlights the importance of antibody surveillance after ABOi-KT.