Objective: Type II mixed cryoglobulinemia (MC) is a systemic vasculitis usually associated with hepatitis C virus (HCV), which may involve the skin, kidneys, and nervous system. Molecular evidence of antigen-driven B cell proliferation is definitively provided in HCV-associated type II MC, and HCV appears to be the key trigger. The present trial was established to investigate the efficacy of therapy with PEGylated interferon alfa-2b (PEG-IFN alfa-2b) plus ribavirin in patients with HCV-related MC vasculitis.
Methods: Nine consecutive patients with HCV-related MC received PEG-IFN alfa-2b (1.5 microg/kg/week) subcutaneously plus oral ribavirin (800-1,200 mg/day) for at least 6 months. The response to treatment was analyzed by comparing clinical, immunologic, and virologic parameters at the initial evaluation with those observed during followup.
Results: The mean +/- SD duration of therapy with PEG-IFN alfa-2b plus ribavirin was 13.5 +/- 2.8 months. After a mean period of 18.6 months following discontinuation of treatment, all 9 patients are alive. Seven patients (78%) had a sustained virologic response and were complete clinical responders. Serum cryoglobulin disappeared in 5 of 9 patients (56%), and complement levels normalized in 80% of the patients. One patient had a partial virologic response with a complete clinical response. In another patient, a clinical relapse of MC vasculitis occurred in association with the reappearance of HCV RNA. Treatment was well tolerated, and no patient had side effects for which discontinuation of therapy was required.
Conclusion: Treatment with PEG-IFN alfa-2b plus ribavirin can achieve a complete clinical response in most patients with HCV-related MC vasculitis. Complete clinical response correlates with the eradication of HCV and requires a shorter treatment period than that previously reported for IFNalpha plus ribavirin.