Fatal autoimmune hemolytic anemia in a child due to warm-reactive immunoglobulin M antibody

Purpose: Autoimmune hemolytic anemia (AIHA) due to warm-reactive immunoglobulin M (IgM) antibodies is rare in adults and has never been described in children. This report describes a pediatric patient with warm AIHA due to high-titer complete IgM antibody. Patients and Methods: A 9- year-old girl with a history of Evan's syndrome had severe anemia, fatigue, and skin mottling. Results: Serologic evaluation revealed a high-titer, high thermal amplitude (37°C) complete IgM autoantibody. Despite aggressive management (including high dose corticosteroids, intravenous immune globulin, cyclophosphamide, mycophenolate mofetil, whole blood exchange transfusions, and cyclosporine A), the patient remained markedly anemic and developed multiorgan system failure related to diffuse in vivo hemagglutination. Her clinical course included cardiovascular collapse caused by agglutinated red blood cells in the right ventricle with outflow obstruction, cerebrovascular infarcts, hepatic failure, and infarction of her extremities. She ultimately died from disseminated Aspergillosis infection. Conclusion: This rare form of AIHA is associated with a dismal prognosis. Early, aggressive treatment is advocated, although it remains to be seen whether the clinical course can be reversed and the outcome improved.