[Hepatitis C].

HCV carriers are supposed to me 100,000,000 worldwide. 5-15% of subjects are infected via haemotransfusion and another significant amount via intravenous drugs; nevertheless in the major part of subjects the via of transmission remains unclear. HCV causes long-term infectious in the host because of its high frequency of mutations. Mutations origin multiple mutants, called quasi-species, who have distinct immunological features and can so easily escape host immune response. Chronic HCV infection leads to cirrhosis in 5-10 years and to a possible hepatocarcinoma in 15-20 years. Nevertheless, it remains unclear why some patients undergo a slight clinical course, while others experience an aggressive one (exitus in less than 5 years). Alpha-interferon (alpha-IFN) is at date the only drug of proven efficacy in HCV chronic hepatitis, even if HCV eradication is a rare event. The goal to obtain is to standardize doses and duration of the treatment.