Clinical features of patients with chronic liver disease associated with hepatitis C virus genotype 1a/I in Okinawa, Japan

Abstract

The clinical characteristics of chronic hepatitis C virus (HCV) carriers with HCV genotype 1a/I infection were investigated and compared with those of chronic HCV carriers infected with 1b/II, 2a/III, 2b/IV and the mixed type of infection. We found that 16 of 408 (3.9%) carriers had HCV genotype 1a infection, comprising four of 67 (6.0%) blood donors, 11 of 263 (4.2%) patients with chronic hepatitis and one of 39 (2.6%) patients with liver cirrhosis. Three of 408 subjects had a mixed infection of genotypes 1a/I and 1b/II. All carriers with genotype 1a (including those with the mixed infection) were of Japanese origin and all, except one who was born in Brazil, were born in Okinawa Prefecture. Nine of 14 patients infected with genotype 1a for whom medical records were obtained had a history suggestive of infection through blood exposure; six had had blood transfusions, one had tattoos, one is a nurse and one had a history of drug addiction. There were no haemophiliacs or other multitransfused patients in the genotype 1a group. Of 10 patients infected with genotype 1a who received interferon (IFN) therapy, four (40%) showed a complete response. Although the small number of patients infected with genotype 1a in the present study precluded statistical analysis of the response to IFN, the response in patients with genotype 1a was better than the response in those infected with genotype 1b and poorer than the response in those patients infected with genotype 2a/III or 2b/IV.

Relation between Reactivity to the NS‐4 Region Peptides of Hepatitis C Virus (HCV) and Clinical Features among Patients Infected with HCV Genotype 1b

“…Since the nucleotide sequence of the core region is well conserved, nearly all patients with an HCV infection have the antibody to the core protein irrespective of HCV genotype (15,17). The antibody to c33c, a recombinant protein included in RIBA-2, is also detected in nearly all Meq, mega (106) equivalents; *P<0.05 when compared with patients negative for either anti-5-1-1 or anti-c100-3.…”

“…patients with type C liver disease (15,17). However, the nucleotide sequences differ in the NS-4 region of the virus among various genotypes (19,25).…”

“…Genotype lb is the most prevalent, followed by genotypes 2a and 2b (14). It has recently been reported that genotype lb is associated with poor response to IFN therapy (6,17). The majority of patients infected with genotype lb have reactivity to all four antigens (5-1-1, c100-3, c33c and c22-3) of the second-generation recombinant immunoblot assay (RIBA-2), while a minority do not have reactivity to either 5-1-1 or c100-3 (15,17).…”

“…According to recent proposals, based upon extensive sequence comparisons of HCV, variants of HCV can be classified into six major groups (types 1 to 6), many of which can be further subdivided into a number of more closely related subtypes (i.e., la, lb) (18). Recent findings indicate that HCV genotypes may influence the outcome of interferon (IFN) therapy (6,16,17), the natural course of the HCV-related chronic disease (9,20,22) and the serological reactivity to the non-structural (NS) region peptides (11,15,19). Three major HCV genotypes (genotypes lb, 2a and 2b) predominate in Japan (14).…”

“…It has recently been reported that genotype lb is associated with poor response to IFN therapy (6,17). The majority of patients infected with genotype lb have reactivity to all four antigens (5-1-1, c100-3, c33c and c22-3) of the second-generation recombinant immunoblot assay (RIBA-2), while a minority do not have reactivity to either 5-1-1 or c100-3 (15,17). Negative reaction to the NS region proteins in RIBA-2 is similar to the reaction pattern seen in patients infected with genotype 2a or 2b, who are known to have better sensitivity to IFN therapy than those infected with genotype lb.…”