Life-Threatening Autoimmune Hemolytic Anemia Treated with Manual Whole Blood Exchange with Rapid Clinical Improvement

Autoimmune hemolytic anemia (AIHA) is a relatively rare disorder with an incidence of 1-3 per 100,000 [1]. Warm AIHA (WAIHA) is typically due to IgG autoantibodies with optimal reactivity at 37°C and account for the vast majority of AIHA cases (80-90%) [1,2]. Clinical presentation can range from an asymptomatic, compensated hemolytic anemia to acute life-threatening hemolysis. Hemolysis is typically extravascular; however, complement-mediated intravascular hemolysis can be seen at high levels of RBC bound antibody (>1000 molecules IgG), in rare IgM WAIHA and in mixed AIHA characterized by IgM and IgG autoantibodies [2-5]. Although death from WAIHA is considered rare, mortality rates of 4-11% have been reported in children [6,7]. Mortality is particularly high in mixed and WAIHA due to IgM autoantibodies possessing high thermal amplitudes [3-5].