The treatment of extrahepatic disease manifestations of HCV has largely paralleled that of hepatic disease. Interferon was reported to have efficacy for MC even before linkage of the syndrome to HCV in 1989, and successful combination therapy with ribavirin was found to eliminate virus and lead to the resolution of immunologic abnormalities associated with extrahepatic disease. In addition, ~75% of HCV-associated indolent asymptomatic lymphoproliferative diseases remit with successful antiviral therapy. However, in many instances, MC (notably cutaneous vasculitis) will relapse with recurrence of virus, and may occasionally persist even after clearance. In particular, side effects of Interferon alpha, including the uncovering of frank autoimmune disease, theoretically may mitigate response of extrahepatic disease to treatment. Peg-interferon increased the response rate of MC, and decreased the duration of treatment, but side effects remained problematic.