INCREASE IN ALANINE AMINOTRANSFERASE (ALAT): Used for many Years in the diagnosis and follow-up of chronic hepatic diseases related to HCV, the determination of ALAT presents various limits: variation from one patient to the other and in the same patient over time, absence of specificity and inconstant increase. HISTOLOGICAL ASSESSMENT OF THE INVOLVEMENT OF THE LIVER: The hepatic needle-biopsy remains the best means of assessing precisely the hepatic impact. Several scores of hepatic involvement exist, the most frequently used is the Metavir score that takes into account not only the necrotic-inflammatory activity but also the fibrosis. OTHER THAN THE HEPATIC NEEDLE-BIOPSY: There are complications with the hepatic needle-biopsy and non-invasive markers of fibrosis and hepatic necrotic-inflammatory activity have been looked for. Two scores have hence been developed from the measurement in the blood of 4 proteins (apolipoprotein A1, alpha2 macroglobulin, haptoglobin and bilirubin) and 2 enzymes (alanine aminotransferase and gamma-glutamyl transpeptidase) which provide an acurate assessment of the fibrosis (Fibrotest) and the necrotic-inflammatory activity (Actitest).