[Cryoglobulinemia and hepatitis C virus infection]

The demonstration of the high prevalence of HCV infection (HCV) in patients with MC has changed the clinico-biologic scenario of MC, supporting its subdivision into two groups: MC HCV- and MC HCV+. The former, which is predominantly a polyclonal cryoglobulinemia, should be regarded as an epiphenomenon of the immune system activation in the course of a variety of chronic infections or autoimmune disorders; the latter, which is a oligo- or monoclonal cryoglobulinemia, referred in the past as "essential mixed cryoglobulinemia", might be expression of an indolent B cell proliferation stimulated by HCV in an antigen-driven mechanism. The association of HCV infection with MC may have a pathogenetic an therapeutic significance. There are a number of reports demonstrating the beneficial effects of alpha-interferon (alpha-IFN) in about a half of patients with chronic HCV and MC. However, after the end of alpha-IFN therapy a recurrence of viremia and cryoglobulinemia is frequently observed and less than 25% of treated patients achieve long term remissions. To improve the sustained response rate, prolonged courses of alpha-IFN monotherapy or a combination of alpha-IFN and ribavirin should be considered. New agents with specific antiviral activity against HCV will probably further improve therapeutic options.