Study Objective: To determine the efficacy of danazol therapy in patients with systemic lupus erythematosus with severe autoimmune thrombocytopenia refractory to other therapies.
Design: Noncontrolled clinical trial, with a minimum of 8 weeks of therapy, the maximum determined by clinical response.
Setting: Referral-based rheumatology clinic at an army medical center.
Patients: Sequential sample of six patients with systemic lupus erythematosus with severe autoimmune thrombocytopenia refractory to high-dose glucocorticoids. Four patients also failed splenectomy, or cytotoxic drugs, or both.
Interventions: Danazol, 200 mg four times per day, was added to the previous therapeutic regimen for at least 2 months.
Measurements and Main Results: All six patients had normal platelet counts within 6 weeks of starting danazol treatment. After resolution of thrombocytopenia for at least 1 month, immunosuppressive medications were tapered; one patient had a relapse. During an average follow-up of 12 months, the danazol dose was lowered in the five remaining patients but could not be discontinued without recurrence of thrombocytopenia. During danazol therapy, platelet-bound IgG antibodies and circulating immune complexes did not decrease significantly. Danazol was well tolerated.
Conclusions: Danazol appears to be a useful adjunctive treatment for refractory autoimmune thrombocytopenia associated with systemic lupus erythematosus.