Abstract
Clostridioides difficile infection is a rare precipitant for patients to develop atypical hemolytic-uremic syndrome, of which the pathogenesis remains unclear. Previous reports suggest activation of cytokine storm from binding of cyotoxins A and B to colonic wall membranes. CASE SUMMARY: We present a case of a previously healthy 21-year-old woman who developed fulminant C. difficile colitis and atypical hemolytic-uremic syndrome requiring abdominal surgery and renal replacement therapy. She was ultimately treated with eculizumab without the use of plasmapheresis and remains in remission with full renal recovery. CONCLUSIONS: Our patient's significant response to terminal complement inhibitor, without the use of plasmapheresis, suggests that the underlying pathology is significantly driven by the alternative complement pathway. We propose that C. difficile-associated atypical hemolytic-uremic syndrome be defined as primary atypical hemolytic-uremic syndrome and strongly consider eculizumab as first-line therapy.