Treatment of hepatitis C-related thrombocytopenia with interferon α

Thrombocytopenia is a common extra-hepatic manifestation of Hepatitis C (HCV) infection. Treatment with steroids may be effective, but can exacerbate the viral infection. Interferon ct(INF-A) has documented efficacy in the treatment of HCV, but its role in the treatment of patients with HCV-related thrombocytopenia is controversal. We have treated 8 patients with HCV infection who had platelet counts less than 50,000/mcl(range: 16 to 46,000/mcl) with INF-A 3MU SQ 3 X week. Planned duration of treatment was 24 weeks. Five patients had no evidence of hepatic cirrhosis or portal hypertension and two patients with cirrhosis had palpable splenomegaly. Only 3 patients tolerated the full treatment course and all three had improvement in platelet counts to over 50,000/mcl. Two other patients had similar improvement in their platelet counts with shorter durations of treatment (6 and 16 weeks respectively). The mean increase in platelet count for the 5 responders was 44,000/mcl (range: 28 to 90,000/mcl). The average peak platelet count in the 5 responders was 81,000/mcl (range: 62 to 136,000/mcI). Duration of response ranged from 4 months to 18⁺ months with the shortest responses observed in the 2 patients treated with the shorter courses of INF-A. Response to treatment was independent of the presence of cirrhosis with 3 of 5 patients without cirrhosis responsing and 2 of the 3 patients with cirrhosis increasing platelet counts to greater than 50,000/mcl. 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. Three patients were studied for the presence of platelet specific anti-glycoprotein antibodies by ELISA and no such antibodies were detected. We conclude that INF-A can be an effective treatment in patients with HCV-related thrombocytopenia. Response correlates closely with its anti-viral effect and therefore, more potent anti-viral combinations such as Ribavirin with INF-A may prove more efficacious.