Successful treatment of autoimmune hemolytic anemia associated with multicentric Castleman disease by anti-interleukin-6 receptor antibody (tocilizumab) therapy

We describe herein the successful treatment of severe autoimmune hemolytic anemia (AIHA) in a patient with multicentric Castleman disease (MCD) by humanized anti-interleukin-6 (IL-6) receptor antibody (tocilizumab) therapy. Inflammatory anemia is commonly reported; however, AIHA is a very rare complication of MCD. In 1996, a 45-year-old Japanese woman was referred to our hospital because of generalized lymphadenopathy, anemia and skin eruptions. Lymph node biopsy demonstrated MCD. She was treated with prednisolone (1 mg/kg/day), which improved the anemia and skin eruptions. In 2009, she suddenly developed Coombs-positive hemolytic anemia. The blood count was as follows: hemoglobin 4.7 g/dl, platelets 490 × 10(9)/l and white blood cell count 9.8 × 10(9)/l. Both direct and indirect Coombs' tests were strongly positive. She was treated with 8 mg/kg tocilizumab every 2 weeks. One month later, her hemoglobin levels rose dramatically to 10.9 g/dl and her haptoglobin level, hypergammaglobulinemia and clinical symptoms had also markedly improved. To the best of our knowledge, this is the first report of the efficacy of tocilizumab in AIHA associated with MCD. The well-established role of IL-6 in the pathogenesis of MCD may have been responsible for the improvement in the AIHA associated with MCD. Anti-IL-6 receptor antibody treatment could be an attractive therapeutic approach for AIHA associated with MCD.