Fatal massive hemolysis caused by immunoglobulin M anti-c antibody in a patient with newly diagnosed B-cell acute lymphoblastic leukemia: a case report.

Delayed hemolytic transfusion reactions (DHTRs) occur secondary to slow, mild IgG-mediated processes against minor red blood cell antigens. Herein, we report the case of a rapidly fatal alloimmune anti-c IgM-mediated hemolysis, a rare, previously undescribed, pathophysiologic scenario. Early recognition of such phenomena can expedite supportive measures and optimize patient outcomes.