Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome in relapsing-remitting multiple sclerosis patients on high-dose interferon β.

Three women aged 34-47 years old, on high dose interferon beta-1a for relapsing-remitting multiple sclerosis, were hospitalized between 2009-2012 for thrombotic thrombocytopenic purpura-hemolytic uremic syndrome. Patients sought medical attention for neurological symptoms including cephalalgia, blurred vision, confusion, focal deficits and seizures. All patients presented thrombocytopenia, hemolytic anemia and arterial hypertension. Despite plasma exchanges, corticosteroids and anti-CD20 treatments, all patients progressed towards severe renal insufficiency and one patient died of hemorrhagic shock. In this report we identify a rare but morbid complication of interferon beta-1a treatment associated with female gender, Caucasian background and low body mass index.