Extrahepatic manifestations of chronic HCV infection.

Several extrahepatic manifestations have been reported in the natural history of hepatitis C virus infection (HCV). Up to 40-74% of patients infected with HCV might develop at least one extrahepatic manifestation during the course of their disease. Mixed Cryoglobulinemia (MC) is the most known and studied syndrome associated with HCV infection. It is a systemic vasculitis that may involve the skin, kidney and nervous system. A frequent reported association is that between HCV infection and non-Hodgkin lymphoma. The cryoglobulinemia may be the intermediary disorder, in fact some persistent forms of cyoglobulinemia can switch over to a more aggressive haematologic disorder. As compared to cutaneous vasculitis described in MC, HCV infection has been associated with dermatological disorders such as porphyria cutanea tarda and lichen planus. Thyroid disease (usually hypothyroidism) is commonly seen in people with HCV. Up to 25% have thyroid antibodies. Several studies described a correlation between HCV and lympho-cytic sialoadenitis, similar to sialoadenitis associated with idiopathic Sjögren syndrome, but we can define as "pseudo- Sjögren syndrome" the one associated with HCV infection, because it shows several differences in the idiopathic form. In the course of chronic HCV infection, a common obser-vation are rheumatological symptoms such as polyarthritis. The clinical pattern of joint involvement in the course of HCV infection varies from a rheumatoid arthritis-like form (very rare), to a non erosive oligoarthritis involving the large-sized and middle joints.