Atypical Hemolytic Uremic Syndrome After Kidney Transplantation: Lessons Learned From the Good, the Bad, and the Ugly. A Case Series With Literature Review

Atypical hemolytic uremic syndrome (aHUS) after kidney transplantation is rare and carries a grave outcome. We present a single-center experience of all aHUS cases since the program's inception. Six patients were diagnosed with aHUS, all after kidney transplants, except for 1 patient. All had nonreactive crossmatches. Delayed graft function (DGF) occurred in 2 patients. Five patients developed aHUS after transplant; 4 (80%) of these patients manifested aHUS ≤ 14 days. All were confirmed by allograft biopsy. Genetic testing was abnormal in all patients except for 1 patient. Actual patient and graft survival during the first year was 100% and 83.3%, respectively. A single graft was lost early in the study secondary to aHUS (eculizumab was not used in the treatment process). Prophylactic and therapeutic use of eculizumab salvaged all other cases. At 1 year, mean creatinine level was 1.9 mg/dL (range, 1.3-2.5). After 6 months of eculizumab treatment (halted in 2 cases) 1 patient had recurrence 2 months later and eculizumab was restarted. However, graft function continued to worsen, and the graft was ultimately lost at 20 months after kidney transplantation. High index of suspicion, prompt diagnosis, and utilization of eculizumab are key to successful salvage of allografts in cases of aHUS after kidney transplantation. aHUS can be prevented by prophylactic use of eculizumab. It still needs to be determined when and if eculizumab therapy can be safely discontinued.