Cryoglobulinemic vasculitis associated with hepatitis C virus infection. A report of eight cases.

Cryoglobulinemia has an unknown etiology in many cases. In the last years, hepatitis C virus has been known to be involved as a causative agent of so called essential mixed cryoglobulinemia. We report 8 patients suffering from cutaneous vasculitis and chronic hepatitis C virus infection. Their sera showed cryoglobulinemia (6 cases mixed, 2 cases not typified), rheumatoid factor and complement consume. Their hepatitis C virus infection was confirmed by PCR. Hepatitis C virus RNA was found by PCR in 6/6 cryoprecipitates and 5/6 supernatants. The patients were followed for 0.5-12 years. Three of them developed renal affection (2 membranoproliferative glomerulonephritis, 1 not biopsied). Two patients were treated with alpha interferon. One patient noted a marked improvement in her cutaneous vasculitis with interferon treatment, lasting for 18 months after the end of treatment. We recommend the search of hepatitis C virus infection in every case of mixed cryoglobulinemia. Interferon therapy may be useful in some of these cases.