Interferon alfa therapy in adults with chronic idiopathic thrombocytopenic purpura.

The role of interferon alfa-2b in the treatment of chronic ITP has not been well documented. One small clinical trial indicated that 84.6% of patients failing to respond to corticosteroid therapy and splenectomy might respond to interferon alfa-2b. These results cannot be extrapolated to all patients refractory to steroids. Subsequent anecdotal reports have not demonstrated a similar response, possibly because the reports included patients who were no longer responsive to corticosteroids, splenectomy, and other agents (i.e., vinblastine, cyclophosphamide, danazol, azathioprine, immunoglobulin). This latter group of patients may have a poor prognosis and less chance of responding to interferon alfa-2b therapy. Therefore, the role of interferon alfa-2b in the treatment of patients with chronic ITP unresponsive to other forms of therapy remains to be established, but it may prove beneficial in some patients. Uncertainty remains as to the reason for lack of interferon alfa-2b efficacy. There is question of a presence of rapid development of antibodies against interferon alfa-2b. In addition, it is unknown whether interferon alfa-2a and interferon alfa-2b are capable of producing similar results in the treatment of chronic ITP.