Atypical Hemolytic Uremic Syndrome in a Patient With Inflammatory Bowel Disease

Atypical hemolytic uremic syndrome is a life-threatening thrombotic microangiopathy due to complement dysregulation that can be triggered by systemic inflammatory states. We describe a patient with inflammatory bowel disease presenting with pain, melena, and laboratory test results showing hemolytic anemia, thrombocytopenia, and acute kidney injury. Subsequent testing led to a diagnosis of atypical hemolytic uremic syndrome, prompting initiation of eculizumab with rapid improvement in his hemolysis, thrombocytopenia, and acute kidney injury. Providers should maintain a high index of suspicion for uncommon but grave conditions associated with inflammatory bowel disease and consider complement testing if thrombotic microangiopathy is suspected.