Steroid Responsive Atypical Hemolytic Uremic Syndrome Triggered by Influenza B Infection.

Atypical hemolytic uremic syndrome (aHUS) is characterized by uncontrolled complement activation leading to thrombotic microangiopathy and severe end-organ damage. The most common trigger for an episode of aHUS in the background of genetic deregulation of the alternative complement pathway is systemic infection. There are only 4 reported cases of aHUS triggered by influenza B thus far. Current accepted therapies for aHUS include plasma exchange and eculizumab. We describe a unique patient with aHUS with a rare membrane cofactor protein mutation triggered by influenza B infection, who achieved complete remission with treatment with high-dose corticosteroids after failure of plasmapheresis.