Treatment of hepatitis C related thrombocytopenia with interferon alpha.

Thrombocytopenia is a common extrahepatic manifestation of hepatitis C (HCV) infection. Treatment with steroids may be effective, but can exacerbate the viral infection. Interferon alpha (INF) has documented efficacy in the treatment of HCV, but its use in the treatment of HCV thrombocytopenia is controversial. We treated eight patients with HCV-related thrombocytopenia, who had platelet counts of fewer than 50 x 10(9)/l (range: 16 to 46 x 10(9)/L) with INF 3 MU SQ three times a week. Planned duration of treatment was 24 weeks. Five patients had no evidence of hepatic cirrhosis, three had cirrhosis, and two had palpable splenomegaly. Only three patients tolerated the full course of treatment, and all three had improvement in their platelet counts to greater than 50 x 10(9)/l. Two other patients had improvement in platelet counts to more than 50 x 10(9)/l with shorter duration of treatment (six and 16 weeks, respectively). The mean increase in platelet count in the five responders was 44 x 10(9)/lL (range: 28 to 90 x 10(9)/l). The average peak platelet count in the responders was 81 x 10(9)/l (range: 62 to 136 x 10(9)/l). Duration of response ranged from four to 18+ months, with the shortest responses observed in the two patients treated with a shorter course of INF. Response was independent of the presence of cirrhosis. Responding patients had improvement in hepatic transaminases, reduction in cryoglobulin and anticardiolipin antibodies, and HCV plasma RNA when tested. Relapse was associated with an increase in these laboratory markers of HCV infection. We conclude that INF can be an effective treatment in patients with HCV-related thrombocytopenia. Copyright 2001 Wiley-Liss, Inc.