Autoimmune Hemolytic Anemia in Children: Mayo Clinic Experience

We studied 35 pediatric patients with autoimmune hemolytic anemia seen at Mayo Clinic from 1994 to 2014. The median age was 10.0 years and 65.7% were males. Most had warm antibodies (80.0%) and some secondary to viral (14.3%) or autoimmune disorders (31.4%). Seven (20.0%) patients presented with Evans syndrome, 3 of whom also had common variable immunodeficiency. The median hemoglobin at diagnosis was 6.1 g/dL and 62.8% patients required red cell transfusions. The severity of anemia was worse among children below 10 years (median 5.5 vs. 7.0 g/dL, P=0.01). Steroid was the initial treatment for 88.5% patients, with overall response rate of 82.7% (68.5% complete, 14.2% partial) and median response duration of 10.7 months (range, 0.2 to 129.7+ mo). After median follow-up of 26.6 months, 8 (22.8%) patients relapsed. Salvage treatments included splenectomy, intravenous immunoglobulin, rituximab, and mycophenolate mofetil. Infectious complications occurred in 9 (25.7%) patients and 1 patient died of cytomegalovirus infection. Four patients had cold agglutinin disease and 3 (75.0%) responded to steroids. Autoimmune hemolytic anemia is a rare disorder in pediatric population and most respond well to steroids regardless of the type of antibody. Infectious complications are common and screening for immunodeficiency is recommended among those with Evans syndrome.