Early relapse of atypical hemolytic uremic syndrome following ABO-incompatible living–related pediatric kidney re-transplant successfully treated with eculizumab

Background: A 3-year-old girl with clinical features of atypical HUS (complement Factor I mutation inherited from an asymptomatic mother and Factor H autoantibodies) was treated with plasma exchange, progressed to kidney failure (KF) aged 4 years, and received an en bloc kidney DCD transplant aged 8 years with primary graft non-function necessitating transplant nephrectomy at the time of transplantation. She subsequently underwent re-transplantation from her father. This is a retrospective study of electronic patient records and medical notes. Case–Diagnosis/Treatment: A 9-year-old girl received an ABO-incompatible (ABOi) living–related kidney transplant from her father with recipient and donor blood groups of O and A, respectively, with baseline recipient anti-A titers 1:128 reducing to 1:4 at the time of transplant with B lymphocyte depletion with rituximab and four sessions of immunoadsorption. Six hours post-transplant, she had recurrence of aHUS and received the first dose of eculizumab. She continues on monthly home eculizumab infusions with stable kidney allograft function and negative anti-A titers 7 years post-kidney transplantation. Conclusions: This is the first report of a pediatric high-risk ABOi living–related kidney transplantation in whom early relapse of aHUS was successfully treated with eculizumab with good long-term patient and allograft outcome.