Natural history of hepatitis C virus infection: from chronic hepatitis to cirrhosis, to hepatocellular carcinoma.
Hepatitis C is a heterogeneous disease and is responsible for considerable mortality and morbidity. The hepatitis C virus (HCV) infects nearly 170 million people world-wide. More than 80% of infected individuals develop chronic infection; the remaining 10-20% develop spontaneous clearance with natural immunity. Acute hepatitis is icteric in only 20% of patients and is rarely severe. The majority of patients who develop chronic HCV infection are asymptomatic; but 60-80% develop chronic hepatitis as indicated by elevated alanine aminotransferase (ALT), around 30% maintain persistently normal ALT levels despite having detectable HCV-RNA in serum. One-third of chronically infected patients develop progressive liver injury, fibrosis and cirrhosis over a period of 20-30 years. The relationship between virus load, HCV genotype, quasi-species variability and progression of liver disease is controversial. Acquired infection after age 40, male sex, excessive alcohol-consumption, hepatitis B virus (HBV) or HIV co-infection, steatosis, and immunosuppressed state have been identified as co-factors associated with progression of fibrosis and development of cirrhosis. In patients with cirrhosis, the incidence of hepatocellular carcinoma is 2-5% per year. At present, HCV-related end-stage cirrhosis is the first cause of liver transplantation.
Leone
N
N
Molinette Hospital, Turin, Italy. leone.nic@tiscalinet.it
Rizzetto
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M
D017088:AIDS-Related Opportunistic Infections; D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000209:etiology*; D004796:Clinical Enzyme Tests; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics; D006526:Hepatitis C / Q000150:complications* / Q000175:diagnosis / Q000276:immunology; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D016867:Immunocompromised Host; D008103:Liver Cirrhosis / Q000209:etiology* / Q000601:surgery; D008113:Liver Neoplasms / Q000209:etiology*; D016031:Liver Transplantation; D008297:Male; D012367:RNA, Viral / Q000032:analysis; D013997:Time Factors; D019562:Viral Load
D012367:RNA, Viral