Platelet and immune responses to oral cyclic dexamethasone therapy in childhood chronic immune thrombocytopenic purpura

Objective: To examine the effectiveness of cyclic oral high-dose (HD) dexamethasone therapy in pediatric patients with chronic immune thrombocytopenic purpura (ITP), which has been reported to cause complete remission in adults with chronic ITP. Study design: Eleven children with primary chronic ITP, with a median disease duration of 28 months (range, 6 to 120 months), were treated with cycles of HD dexamethasone therapy. Results: Excellent short-term responses (initial platelet counts ≤50 x 10⁹/L, increasing to > 100 x 10⁹/L within 72 hours of completion of an HD dexamethasone cycle) were observed in 78% of 41 cycles. Long-term effects include one complete response (platelet count ≤150 x 10⁹/L) and three partial responses (platelet count ≤50 and < 150 x 10⁹/L) in 11 children followed for 6 or more months after completing cyclic HD dexamethasone therapy. Because side effects were substantial, three children did not complete their sixth treatment cycle. At day 6 of treatment, B lymphocytes were significantly increased (p = 0.005). Conclusions: Dexamethasone, given orally in high doses, is an effective drug in achieving short-term platelet responses, but it induced long-term remissions in fewer than half of the children with well-established chronic ITP. Its effect on B lymphocytes requires further elucidation. A prospective, controlled study will be needed to establish whether cyclic HD dexamethasone therapy can alter the natural history of children with early chronic ITP and thus avoid splenectomy.