Influenza A H1N1 Triggering Complement-Mediated Hemolytic Uremic Syndrome

Complement-mediated hemolytic uremic syndrome (CM-HUS) is a condition characterized by hemolytic anemia, thrombocytopenia, and renal impairment, typically associated with a chronic dysregulation of the complement system. Few adult cases of CM-HUS triggered by influenza infection have been described. Here we present a case of a 56-year-old female with multiple myeloma receiving cancer treatment who presented with Influenza A H1N1-associated CM-HUS. She was treated with anti-complement therapy and at her 1-month follow-up had complete resolution of renal dysfunction and hemolytic anemia. This case highlights influenza infection as a trigger for CM-HUS in an immunocompromised adult and the role of anti-complement therapies.