Eculizumab for Congenital Atypical Hemolytic–Uremic Syndrome

To the Editor: Atypical hemolytic–uremic syndrome of infancy is a rare disorder that is associated with thrombotic microangiopathy and acute renal failure. It often involves complement dysregulation. 1 , 2 Plasma infusions have variable efficacy, and end-stage renal disease often develops in children who are unresponsive to plasma therapy. 1 , 2 We report on a patient with congenital relapsing atypical hemolytic–uremic syndrome who was unresponsive to plasma therapy but had a response to eculizumab, a humanized monoclonal antibody against terminal complement protein C5. 3 An 18-month-old boy was admitted with a fourth relapse of congenital atypical hemolytic–uremic syndrome. He was born at 34 weeks' . . .