Background:
Most of adult patients with chronic immune thrombocytopenic purpura (ITP) that was refractory or relapsed to high-dose corticosteroid have been treated with splenectomy as a 2nd line treatment. However, these patients may have increased morbidity and mortality according to the operation and the increased risk of infection for a lifetime after splenectomy. Despite of the above risks, 30∼40% of these patients can't maintain remission. Furthermore, the remission rate after splenectomy is relatively lower in patients with corticosteroid-refractory chronic ITP than that in those patients with corticosteroid- responsiveness. We studied whether danazol, an attenuated androgen, is useful or safe as 2nd line treatment for chronic ITP instead of splenectomy and which factors are associated with the response to danazol.
Methods:
Among the patients with chronic ITP who failed corticosteroid therapy in our hospital, 28 patients who received danazol as the 2nd line treatment were analyzed retrospectively. A complete response was defined that the platelet count was increased to 150×103/ՌL, and a partial response was defined that the platelet count was increased above 50×103/ՌL or there was an increased platelet count of more than 20×103/ՌL from the pre-treatment platelet count when the platelet count was above 50× 103/ՌL at the time of danazol therapy.
Results:
The median age of patients was 44 years (range: 19∼67) and the number of male patients was 9 (32.1%) and the number of females was 19 (67.9%). The starting daily doses of danazol were variable from 200 to 600mg, though most of the patients were treated with 400mg daily (18 cases, 64.3%). The median duration of danazol therapy was 201.5 days (range: 13∼973) and the median duration from ITP diagnosis to danazol treatment was 56 days (range: 20∼2,430). Among the accrued 28 patients, 22 patients showed a response to danazol (78.5%); there were 6 patients (21.4%) with a complete response and 16 patients (57.1%) with a partial response. The median duration from danazol treatment to response was 30 days (range: 0∼180). The median response duration of danazol treatment was 330 days (95% CI: 182∼478) by the Kaplan-Meiyer method. For the danazol-responsive patients, 9 patients (40.9%) remained in remission and 13 patients (59.1%) relapsed. Grade 3∼4 toxicity was observed in two patients and three patients stopped danazol because of adverse effects. Hepatotoxicity was the most common toxicity.
Conclusion:
Our findings suggest that danazol is a beneficial, safe choice as the 2nd line treatment for patients with chronic ITP that was refractory or relapsed to corticosteroid.

Keywords: Danazol, Corticosteroid, Chronic immune thrombocytopenic purpura