Clinical and virological findings in mixed cryoglobulinaemia

. Objectives. As a close relationship has been established between mixed cryoglobulinaemia and hepatitis C virus (HCV) infection, the clinical, histological and virological findings of patients affected by mixed cryoglobulinaemia were determined. Design. Hepatitis C virus infection was investigated by the presence of anti-HCV antibodies and PCR amplification of the 5′ untranslated region (5′ UTR), and the genotype of HCV was also determined according to Okamoto. A bone marrow biopsy was performed in all patients and liver and kidney biopsies when indicated. Subjects. Eighty-two subjects affected by mixed cryoglobulinaemia were enrolled in this study. Results. The prevalence of anti-HCV antibodies was high (83%); PCR amplification of the 5′UTR region was performed in 52 subjects and in 44 of them (85%) the results were positive. In the same subjects, the Core region amplification was positive in 46 cases (88%). A high prevalence of genotype II was found (54%). Chronic liver disease was present in 55 patients (67%). Bone marrow biopsies showed the presence of low-grade non-Hodgkin's lymphomas in 11 cases (13%). Membrano-proliferative glomerulonephritis was found in seven subjects (8%). Conclusions. Mixed cryoglobulinaemia is associated with HCV infection in the nearly all cases. Several HCV genotypes are involved in the pathogenesis of this disease. Mixed cryoglobulinaemia is associated with a high prevalence of chronic liver disease, low-grade non-Hodgkin's lymphomas and membranoproliferative glomerulonephritis.