Hepatitis C virus syndrome： A constellation of organ- andnon-organ specific autoimmune disorders, B-cell non-Hodgkin＇s lymphoma, and cancer

The clinical course of chronic hepatitis C virus （HCV）infection is characterized by possible developmentof both liver and extrahepatic disorders. The tropismof HCV for the lymphoid tissue is responsible forseveral immune-mediated disorders; a poly-oligoclonalB-lymphocyte expansion, commonly observed in ahigh proportion of patients with HCV infection, areresponsible for the production of different autoantibodiesand immune-complexes, such as mixed cryoglobulins.These serological alterations may characterize a varietyof autoimmune or neoplastic diseases. Cryoglobulinemicvasculitis due to small-vessel deposition of circulatingmixed cryoglobulins is the prototype of HCV-drivenimmune-mediated and lymphoproliferative disorders;interestingly, in some cases the disease may evolve tofrank malignant lymphoma. In addition, HCV shows anoncogenic potential as suggested by several clinicoepidemiologicaland laboratory studies; in addition tohepatocellular carcinoma that represents the mostfrequent HCV-related malignancy, a causative role ofHCV has been largely demonstrated in a significantpercentage of patients with isolated B-cells non-Hodgkin＇s lymphomas. The same virus may be alsoinvolved in the pathogenesis of papillary thyroid cancer,a rare neoplastic condition that may complicate HCVrelatedthyroid involvement. Patients with HCV infectionare frequently asymptomatic or may develop onlyhepatic alteration, while a limited but clinically relevantnumber can develop one or more autoimmune and/orneoplastic disorders. Given the large variability of theirprevalence among patients＇ populations from differentcountries, it is possible to hypothesize a potential role ofother co-factors, i.e. , genetic and/or environmental, inthe pathogenesis of HCV-related extra-hepatic diseases.