Recombinant HGV Core Antigen

Infections with hepatitis B and C viruses (HBV, HCV) are widespread in human populations throughout the world, and are major causes of chronic liver disease and liver cancer. HBV HCV and the related hepatitis G virus or GB virus C (referred to here as HGV/GBV-C) are capable of establishing persistent, frequently lifelong infections characterized by high levels of continuous replication. All three viruses show substantial genetic heterogeneity, which has allowed each to be classified into a number of distinct genotypes that have different geographical distributions and associations with different risk groups for infection. Information on their past transmission and epidemiology might be obtained by estimation of the time of divergence of the different genotypes of HCV, HBV and HGV/GBV-C using knowledge of their rates of sequence change. While information on the latter is limited to short observation periods and is therefore subject to considerable error and uncertainty, the relatively recent times of origin for genotype of each virus predicted by this method (HCV, 500 2000 years; HBV. 3000 years, HGV/GBV-C, 200 years) are quite incompatible with their epidemiological distributions in human populations. They also cannot easily be reconciled with the recent evidence for species-associated variants of HBV and HGV/GBV-C in a range of non-human primates. The apparent conservatism of viruses over long periods implied by their epidemiological distributions instead suggests that nucleotide sequence change may be subject to constraints peculiar to viruses with single-stranded genomes, or with overlapping reading frames that defy attempts to reconstruct evolution according to the principles of the 'molecular clock'. Large population sizes and intense selection pressures that optimize fitness may be additional factors that set virus evolution apart from that of their hosts.

Background. Epidemiological data indicate that Hepatitis G virus (HGV) is transmitted predominantly through parenteral routes, with a high seroprevalence among injection drug users (IDUs), although sexual transmission has also been reported. In this study our objective was to compare the frequency of HGV infection in two groups of HIV-positive patients including IDUs and those with sexual risk of exposure. Methods. Presence of HGV-RNA was analyzed in serum samples from 82 HIV-infected patients including 52 IDUs and 30 cases with sexual (heterosexuals) risk of exposure by reverse transcriptase-nested polymerase chain reaction. Hepatitis B surface antigen (HBsAg), Hepatitis B Surface antibody (anti-HBs), Hepatitis C antibody (anti-HCV), alanine aminotransferase (ALT) levels, HIV viral load and CD4 cells Count were also tested in all subjects. Results. The overall prevalence of HGV infection was 10.97% in HIV infected patients, with no statistically significant difference between the two groups (13.5% among IDUs vs. 6.7% among the sexual cases). We found a higher frequency of HGV co-infection with HCV in IDUs than in the sexual group (11.5% vs. 3.3%). There was no statistically significant difference between IDUs and the sexual group regarding age, viral load, CD4 cells count, ALT levels and the prevalence of HBV infection. Conclusion. The overall prevalence of HGV infection was relatively high in HIV infected patients. HGV-RNA was found more frequently in patients with injection drug use than in those with sexual risk of exposure.