Correlations between the spectra of antibodies to HCV proteins represented by various antigenic determinants and clinical variants of chronic HCV infection were studied. Synthetic peptides core-16, NS4-20, and NS5-23 simulating the immunodominant regions of the core, NS4 and NS5 proteins and recombinant proteins core-114 and NS4-86 were used as antigens. The results indicate that if the serum of an HCV patients contains no IgG to both antigenic determinants of NS4 or to NS5 in combination with any core antigenic determinant, a clinical and biochemical remission is highly probable. Chronic hepatitis C is characterized by the presence of IgG in high titers to both antigenic determinants of NS4 protein, particularly in combination with anti-NS5 IgG in low titers or none at all, or high titers of anti-core-16 IgG in combination with high titers of anti-NS4-20 IgG.

Five overlapping cDNA fragments of hepatitis C virus (HCV) isolate 274933RU, obtained by RT-PCR, were amplified and cloned. Complete nucleotide RNA sequence has been determined. The genomic organization of 274933RU was, from 5' to 3' terminals, 5' UTR (341 nt), polyprotein ORF (9033 nt), 3' UTR (40 nt except for the poly(U-UC) and polypyrimidine stretch), and X-tail (98 nt). Phylogenetic analysis of the core and NS5 genes showed that the isolated strain belonged to HCV 1b subtype.

Study of prevalence of hepatitis G virus (HGV) markers in different risk groups showed the presence of HGV RNA in 3.2% blood donors, 24.2% patients with hepatitis C (HCV), and 28% patients with hemophilia. HGV antibodies were detected in 11.3% donors, 16.0% patients with HCV, 13.4% patients with hemophilia, and 8.5% HIV-infected subjects. Anti-E1 HGV were more often detected in the absence of HGV RNA. Antibodies to HGV E2 protein were significantly more often detected in adult HCV patients but not in adolescent patients aged 8-15 years.

Clinical and biochemical features of the acute phase of icteric hepatitis C in various HCV genotypes have been studied. The HCV genotypes determine the duration of incubation period and some clinical signs in the preicteric and icteric periods of acute hepatitis C. The biochemical picture and formation of chronic hepatitis virtually did not depend on the virus genotype.

The prevalence of hepatitides B and C was evaluated in 140 patients treated by hemodialysis. Almost half of patients (48%) had acute hepatitis B which completely resolved. Acute hepatitis B was detected in 6% in the course of observation. In 6% chronic hepatitis B was diagnosed, and in 24% chronic hepatitis C. A combination of hepatitides B and C was diagnosed in 2% patients. Only 12% patients were not infected with hepatitis. Genotype 1b predominated in patients with HCV infection (73%); genotypes 1a, 21, and 3a were equally incident (9%). Replication of HBV and HCV in patients with uremia under conditions of hemodialysis was detected in 83 and 86% patients, respectively. Relationship between HBV and HCV infection and the duration of hemodialysis treatment was analyzed. The percentage of non-infected patients persistently decreased, and the time course of HBV and HCV infection was different. Infection with HBV after the beginning of hemodialysis occurred sooner (16.0 +/- 4.0 months) than with HCV (30.2 +/- 4.6 months, p < 0.04). The levels of SGPT and SGOT in patients with various manifestations of HBV and HCV infection treated by hemodialysis were followed up.

Nucleotide sequence of a 356 nt fragment of the NS5 region of the hepatitis G virus (HGV) genome was determined in 7 strains isolated in Russia, Kazakhstan, and Kyrghyzstan. Philogenetic analysis showed that all isolated strains genetically differed from the West African strain described previously (type 1) and are closely related to strains isolated in the USA and South-Eastern Asia (type 2). Hence, the strains from Russia, Kazakhstan, and Kyrghyzstan belong to type 2 variant of HGV genome.

The incidence of markers of hepatitis C virus (HCV in the blood of 4216 normal subjects living in the European Russia (Northern, North-Western, Central, Central Chernozem, Volga-Vyatka, Volga, and North Caucasian regions), in the Urals, in Siberia (Eastern Siberian region), in the Far East, and in Monogolia is assessed. The incidence of antibodies to HCV varied from 0.7% in the Central region to 3.8% in the Central Chernozem and 10.7% in Mongolia. HCV genotyping (identification of 1a, 1b, 2a, 2b, and 3a genotypes) was performed using 469 RNA of HCV-positive sera of donors and patients collected in Russia, Moldova, Turkmenistan, and Mongolia. The 1b genotype predominated everywhere (68.9%), its incidence being the highest in Moldova (96%). Unclassifiable variants of HCV were found in 28 (6%) of sera. The regularities of HCV genotypes circulation in the European Russia were the same as in other European countries, whereas their prevalence in Eastern Russia was rather like that in China or Japan. The prevalence of genotypes did not depend on the clinical manifestations of diseases caused by HCV.

We tested hepatitis C virus (HCV) antibody in 4 216 sera collected from healthy people living in European part of Russia (including Northern, North-Western, Central, Central-Blacksoil, Volga-Vyatka, Volga, and North-Caucasian regions), non-European part of Russia (the Urals, East-Siberia, and the Far-East regions) and Mongolia. Prevalence of HCV antibody varied significantly by regions, ranging from 0.7% in Central region of European part of Russia to 10.7% in Mongolia. Genotyping of HCV (into 1a, 1b, 2a, 2b, and 3a) was performed on 469 sera from blood donors and patients (in Russia, Moldova, Turkmenistan, and Mongolia) who were positive for both HCV antibody and RNA. Genotype 1b was the most dominant genotype irrespective of regions (68.9%), with the highest rate in Moldova (96%). HCV unclassificable into genotypes 1a-to-3a was found in 28 (6.0%) samples: particularly 4 of 10 samples from Lipetzk were untypable. Overall, HCV genotypes in European part of Russia were more similar to those in European countries, while those in Eastern part of Russia more similar to China or Japan. Genotype distribution was not associated with the clinical expression of HCV disease: acute hepatitis, chronic hepatitis or liver cirrhosis.