Efficacy of danazol with autoimmune thrombocytopenia

Seventy-nine cases of autoimmune thrombocytopenia seen by the Baylor Hematology section of The Methodist Hospital between 1991 and 1996 were retrospectively reviewed to assess the effectiveness of danazol in the treatment of autoimmune thrombocytopenia. Among the 42 patients who received danazol, the mean initial platelet count prior to treatment was 24.3 ± 17.4 (SD) x 10⁹/L with a mean duration of disease of 53 months. Most cases were idiopathic, but some patients had underlying secondary disorders (rheumatoid arthritis, systemic lupus erythematosus, HIV, and/or Evans' syndrome). Overall 57% of the patients treated with danazol had an excellent or a good response with three patients who had unmaintained remission for >11 months. Minimal side effects were noted. Fifty percent of the patients with associated secondary disorders achieved an excellent or good response. The hemolytic component of all three Evans' syndrome cases was well controlled with danazol. In two cases, danazol was effective where a variety of other treatment regimens were not. An excellent or a good response was found in 58%, 62%, and 53% in patients >65 years old, between 45 and 65 years old, and <45 years old, respectively. Response rates were similar in males and females. Seventy percent of the nonsplenectomized patients had an excellent or a good response compared to 33% in postsplenectomy patients. Overall in view of its favorable side-effect profile, it is rational early on to attempt to abrogate the need for splenectomy, it may salvage splenectomy failures, and there is a reasonable response rate in those refractory to multiple prior therapies.