Aplastic anemia and concomitant autoimmune diseases

The association of aplastic anemia (AA) with other autoimmune diseases (AID) has been described but so far not systematically evaluated. We assessed the incidence and the outcome of concomitant AID in a retrospective, single-center study of 243 patients with severe AA treated between 1974 and 2006 with either immunosuppression (186) or hematopoietic stem cell transplantation (57) and a median follow-up time of 9.3 years (0-33). Clinically manifest AID were observed in 24 out of 243 (10 +/- 3.7%) patients. Age at diagnosis of AA was significantly younger in patients without AID compared to patients with AID (median, 20 versus 52 years; P > 0.001). In 12 patients where the diagnosis of AID was done before AA therapy, response to antithymocyte globulin was good for AA (ten out of 12) but not for AID (2 out of 12). In 13 patients in which AID occurred after first-line therapy, the median time to the AID was 7 years (range 3 months-27.5 years).