title: Hepatitis C virus genotypes: an investigation of type-specific differences in geographic origin and disease.
abstract: Because of the nucleotide sequence diversity of different isolates of hepatitis C virus, it has become important to clarify whether distinct genotypes of hepatitis C virus vary with respect to pathogenicity, infectivity, response to antiviral therapy and geographic clustering. We assessed nucleotide sequence variability in the 5' noncoding region of hepatitis C virus, using restriction enzymes to analyze the distribution of hepatitis C virus genotypes, in 80 patients with chronic hepatitis C virus infection. Genotypes were correlated with demographic, clinical and histological features. Thirty-seven patients were infected with type 1, 10 had type 2 and 8 had type 3, and another 23 were infected with a new distinct hepatitis C virus type now classified as type 4. Two were infected with variants whose classification are uncertain. Types 1, 2 and 3 were found in patients from the United Kingdom, southern Europe, Asia, Africa and South America. Nineteen of 23 type 4 genotype isolates were from Middle Eastern patients, compared with 0 of 37 type 1 isolates (p < 0.001). Of 21 Middle Eastern patients, 19 (90.4%) had type 4 hepatitis C virus (p = 0.001, odds ratio = 9). We found no significant difference between the mean ages or mean serum aminotransferase concentrations between the various types. Types 1, 2, 3 and 4 were found in patients with mild-to-moderate disease or severe disease. However, 21 of 29 (72.4%) patients with type 1 who underwent liver biopsy had severe chronic hepatitis, cirrhosis or hepatocellular carcinoma histologically; 8 had mild or moderate chronic hepatitis without cirrhosis (p = 0.03, odds ratio = 2.6).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Royal Free Hospital and School of Medicine, London, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Dusheiko
authors.forename: H
authors.initials: H
authors.lastname: Schmilovitz-Weiss
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: F
authors.initials: F
authors.lastname: McOmish
authors.forename: P L
authors.initials: PL
authors.lastname: Yap
authors.forename: S
authors.initials: S
authors.lastname: Sherlock
authors.forename: N
authors.initials: N
authors.lastname: McIntyre
authors.forename: P
authors.initials: P
authors.lastname: Simmonds
mesh_terms: D000328:Adult; D002908:Chronic Disease; D016000:Cluster Analysis; D004534:Egypt / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D006526:Hepatitis C / Q000453:epidemiology / Q000382:microbiology* / Q000628:therapy; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D008877:Middle East / Q000453:epidemiology
chemical_list: D016898:Interferon-alpha