Course and outcome of hepatitis C.
The hepatitis C virus (HCV) is a small enveloped RNA virus belonging to the family flaviviridae and genus hepacivirus. The HCV RNA genome is 9,600 nucleotides in length and encodes a single polyprotein that is post-translationally cleaved into 10 polypeptides including t3 structural (C, E1, and E2) and multiple nonstructural proteins ([NS] NS2 to NS5). The NS proteins include enzymes necessary for protein processing (proteases) and viral replication (RNA polymerase). The virus replicates at a high rate in the liver and has marked sequence heterogeneity. There are 6 genotypes and more than 90 subtypes of HCV, the most common in the United States being 1a and 1b (approximately 75%), 2a and 2b (approximately 15%), and 3 (approximately 7%). Acute hepatitis C is marked by appearance of HCV RNA in serum within 1 to 2 weeks of exposure followed by serum alanine aminotransferase (ALT) elevations, and then symptoms and jaundice. Antibody to HCV (anti-HCV) tends to arise late. In acute resolving hepatitis, HCV RNA is cleared and serum ALT levels fall to normal. However, 55% to 85% of patients do not clear virus, but develop chronic hepatitis C. Chronic hepatitis C is often asymptomatic, but is usually associated with persistent or fluctuating elevations in ALT levels. The chronic sequelae of hepatitis C include progressive hepatic fibrosis, cirrhosis, and hepatocellular carcinoma. Extra-hepatic manifestations include sicca syndrome, cryoglobulinemia, glomerulonephritis, and porphyria cutanea tarda. Knowledge of the course and outcome of hepatitis C is important in developing approaches to management and therapy.
Hoofnagle
Jay H
JH
Division of Digestive Diseases and Nutrition, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA. HoofnagleJ@extra.niddk.nih.gov
D000937:Antigen-Antibody Reactions; D014644:Genetic Variation; D016174:Hepacivirus / Q000235:genetics; D006526:Hepatitis C / Q000150:complications* / Q000276:immunology / Q000503:physiopathology* / Q000821:virology; D019698:Hepatitis C, Chronic / Q000276:immunology; D006801:Humans; D011315:Preventive Medicine / Q000379:methods; D014765:Viral Vaccines / Q000627:therapeutic use
D014765:Viral Vaccines