[Hepatitis C: cryoglobulinemia and non-Hodgkin lymphoma]

Hepatitis C virus infection plays a major role in the pathogenesis of mixed cryoglobulinemia, promoting activation and expansion of B cells. These molecular rearrangements induce synthesis of cryoglobulins and the appearance of cryoglobulinemic vasculitis. Clearance of the virus promotes resolution of the clinical manifestations and immunological disorders seen in mixed cryoglobulinemia in a large percentage of patients, but not in all. In some cases, cryoglobulinemia could appear after sustained response. Several steps in the pathogenesis of mixed cryoglobulinemia are strongly related to HCV infection and when the virus is eliminated, the disease course improves. However, independent steps related to other factors do not improve following viral clearance. In some types of low-grade non-Hodgkin lymphoma (lymphomoplasmocytic lymphoma, marginal zone lymphoma) sustained response following antiviral treatment induces remission of the neoplasm. HCV has a minor role in aggressive lymphomas and clearance of the virus may not induce remission, but could decrease the hepatotoxicity associated with the chemotherapy.Therefore, in chronic hepatitis C, the combination of peginterferon + ribavirin is strongly recommended in treating symptomatic mixed cryoglobulinemia and HCV-related non-Hodgkin lymphomas.