Atypical Hemolytic Uremic Syndrome Associated With Clostridium Difficile Infection

Atypical hemolytic uremic syndrome (aHUS), defines as non-Shiga toxin HUS, is thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, consumptive thrombocytopenia, and renal impairment. aHUS is associated with high morbidity and mortality, necessitating the need for an early diagnosis to limit target organ damage. Mutations or autoantibodies against specific complement factors over-activate the complement system forming microthrombi. aHUS has the potential to cause multi-organ system dysfunction, but it predominantly affects the kidneys. aHUS is treated with eculizumab, a terminal blocker of the complement system. Clostridium difficile infection is a rare precipitant of aHUS. We present a case of aHUS associated with Clostridium difficile infection in a 60-year-old female patient that was successfully treated with eculizumab.