Chronic hepatitis C virus disease: an evaluation of procedures for diagnosis and treatment

Chronic hepatitis C virus (HCV) disease is a major health problem worldwide. HCV infection has a chronicity rate of about 70%. A high percentage of these patients have slowly progressive liver disease ultimately leading to cirrhosis and hepatocellular carcinoma. Increased understanding of the viral biology and host-virus interaction has induced new diagnostic and therapeutic criteria. Up to 70% of anti-HCV-positive subjects with persistently normal serum ALT have chronic hepatitis histologically. A normal ALT does not exclude viral replication and after therapy ALT does not correlate with viral clearance. Therefore, biochemical parameters alone do not adequately inform about disease severity and effect of the antiviral therapy. Monotherapy with interferon 3 times 3 MU/week for 6 months has an immediate response rate of ca. 35% with early relapse in at least half of the patients. Several trials have been conducted to improve results. A 1-year duration of therapy leads to a sustained response rate of approximately 40%. Absence of HCV-RNA early after start of therapy could enable selection of the patients who will most probably benefit from treatment. Viral load, genotype and quasi-species variability are correlated with disease severity, prognosis and outcome of therapy; these viral parameters may be incorporated in studies of more individualized therapeutic strategies.