REVIEW ON HEPATITIS-C VIRUS - VARIABILITY AND CONSEQUENCES

Hepatitis C virus (HCV) is the main etiologic factor of post-transfusi onal and sporadic hepatitis, called non-A non-B in the past. These inf ections are characterized by a very high number of chronic carriers al ways with a persistent viral increase, but often at a slow pace. The s eriousness of liver disease differs from one individual to another, va rying from an asymptomatic form with minor or no liver injuries, to ci rrhosis and hepatocellular carcinoma. Physiopathological mechanisms in volved in liver injuries are still poorly understood. The direct role of immune response and of possible genetic factors is still under stud y. This review aims at summing up the discovery of HCV, its structure, and its variability in the various genome regions in the same individ ual and from one individual to another. The different methods and tech niques to analyze this variability are also reviewed, as well as the v arious suggested ways of classifying the different types. The geograph ical distribution and both clinical and biological consequences of thi s variability are also discussed. (C) 1998 Elsevier, Paris.