[Detection of type specific antibodies to hepatitis C virus NS4 protein in hepatitis C patients by enzyme immunoassay]. / Vyiavlenie tipospetsificheskikh anti-HCNS4-antitel u bol'nykh gepatitom C metodom immunofermentnogo analiza.

A multi-enzyme immmune-assay test system was designed for serotyping of genotypes hepatitis C virus (HCV) and a method of such typing of the serum of patients with hepatitis C was worked out. The above test-system was worked out on the basis of a study of 10 type-specific peptides modeling different fragments from NS4-protein variable region of HCV. The designed test system was evaluated by using a set of 42 serum samples obtained at random from patients with chronic hepatitis C, which had been preliminarily genotyped by polymerase chain reaction. The serotyping makes it possible to identify the type-specific antibodies in the blood sera of patients, including those cases when viremia was absent. Differences in the circulation of HCV in Moscow (Russia) and Vitebsk (Byelorussia) were established by using the designed test-system.

[Seroconversion to various hepatitis C virus antigens in patients with hepatitis C from various sources]. / Issledovanie serokonversii k razlichnym antigenam virusa gepatita C s razlichnymi iskhodami.

A total of 136 patients with acute icteric hepatitis C, including patients with known outcome, were examined. Therefore, 46 serological samples, obtained from 13 patients with subsequent remission, and 63 samples, obtained from 13 patients, who subsequently developed the chronic disease stage, were analyzed. The serum of known outcome patients were examined, by using the immune-enzyme analysis method, to the antibodies of both class IgG, and IgM. Differences in the dynamics of the immune humoral response were established with due regard for a pathological course process, including the acute disease stage. The obtained results are interesting because of their prognostic values.

[Spectrum of antibodies to HCV antigens in patients with different clinical patterns of chronic HCV infection]. / Spektr antitel k razlichnym antigenam HCV pri raznykh variantakh techeniia khronicheskoi HCV-infektsii.

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.

[Diagnostic significance of antibody detection to various hepatitis C virus antigens in patients with acute and chronic HCV-infection]. / Diagnosticheskaia znachimost' opredeleniia antitel k razlichnym antigenam virusa gepatita C u patsientov s ostroi i khronicheskoi HCV-infektsiei.

AIM: To examine diagnostic value of antibodies to various HCV antigens in patients with acute and chronic HCV-infection. MATERIAL AND METHODS: Enzyme immunoassay has tested blood sera from 136 patients with icteric acute hepatitis C (AHC) and 45 patients with chronic HCV infection for IgG antibodies to antigens of proteins core, NS4, NS5, HCV. Synthetic peptides core-16, NS4-20, NS5-23 were used as antigens. RESULTS: Patients with icteric AHC had IgG antibodies to antigens of both structural protein core and non-structural proteins NS4, NS5 of HCV as early as the first 10 days of jaundice. Occurrence of anti-core and anti-NS4 increases with the disease duration. Incidence of anti-NS4 correlated with duration of previous intravenous drug addiction. In patients with AHC early in the icteric period anti-core, anti-NS4, anti-NS5 were present less frequently than in patients with chronic HCV infection having elevated levels of AlAT. Significant differences were found neither with the group with normal AlAt nor in the spectrum of the detected antibodies between patients with acute and chronic HCV infection. CONCLUSION: Despite different frequency of anti-core, anti-NS4, anti-NS5 detection in patients with icteric AHC and patients with chronic HCV-infection and high AlAT, their high incidence rate in this or that group and absence of differences by the spectrum of the studied antibodies do not allow the fact of their detection to be a diagnostic marker differentiating acute HCV-infection with chronic one.

[Serological study of hepatitis C virus NS5 protein epitopes and their clinical and diagnostic significance]. / Serologicheskoe issledovanie épitopov belka NS5 virusa gepatita C i ikh znachenie dlia kliniki i diagnostiki.

Three peptides corresponding to the 2295-2317 aa NS5 HCV region and individual parts of this region were synthesized. Antigenic properties of these peptides were investigated. The 2295-2317 aa region contains at least two epitopes of different nature. The full-sized peptide is more promising for the diagnostic studies. Optimal conditions for ELISA with this peptide were defined, allowing the maximum complete utilization of the potentialities of both epitopes.

[Hep-A-in-Vac, a Russian cultured concentrated inactivated vaccine against hepatitis A]. / Izuchenie otechestvennoi kul'tural'noi kontsentrirovannoi inaktivirovannoi vaktsiny protiv gepatita A "Gep-A-in-Vak".

The results of the study of the reactogenicity, safety and immunological activity of Russian cultural vaccine against hepatitis A are presented. The vaccine was found to have specific safety, moderate reactogenicity and pronounced immunological activity. In addition, the study of the prophylactic efficiency of the vaccine in the pre-epidemic period of the outbreak of hepatitis A morbidity in a group exceeding 14,000 adults was carried out. The study revealed high prophylactic efficiency of the vaccine (its efficiency rate was equal to 97.7%). On the basis of materials thus obtained vaccine "Hep-A-in-Vac" was recommended for use in medical practice for the prophylaxis of hepatitis A among adults.

[Regularities in the spread of hepatitis C virus and its genotypes in Russian and countries within the former USSR]. / Zakonomernosti rasprostraneniia virusa gepatita C i ego genotipov v Rossii i stranakh SNG.

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.

Langmuir films from antibodies based on amphiphilic polyelectrolytes.

A technique for forming Langmuir films from antibodies based on an amphiphilic polyelectrolyte was developed. The physicochemical and immunochemical properties of the Langmuir films obtained were studied. The interaction of HBsAg with the films was found to be described by a model with one binding site, whereas that of HBsAg with antibodies adsorbed on a polystyrene plate, by a model with a positive cooperativity. The use of the novel Langmuir films from antibodies increases the sensitivity of the immunoenzyme assay.

Prevalence of hepatitis C virus and distribution of its genotypes in Northern Eurasia.

We tested hepatitis C virus (HCV) antibody in 4216 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 unclassifiable 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.

[Prevalence of genotypes of the hepatitis C virus, circulating in northwestern and central parts of Russia]. / Rasprostranenie genotipov virusa gepatita C, tsirkuliruiushchikh na territoriiakh severo-zapadno i i tsentral;no i chaste i Rossii.

Testing of 90 sera for antibodies to hepatitis C virus (HCV) by genotyping methods resulted in determination of the genotype in 83 cases: 47 cases with 1b genotype, 27 with 1a, 7 with 3a, 1 with 2a, and 1 with 2b genotype. Hence, preliminary data indicate the predominance of HCV genotype 1b among patients with hepatitis C in these regions of Russia.

[The current problems in the epidemiology and prevention of enteric viral hepatitis in Russia]. / Aktual'nye voprosy épidemiologii i profilaktiki énterial'nykh virusnykh gepatitov v Rossii.

The presence of great differences in the activity of the epidemic process of hepatitis A (HA) in some regions of Russia is shown and the data necessary for establishing the structure of HA foci in groups of children, as well as the proportion of different forms of the disease registered in such foci (the icteric form in 22.7% of patients, the obliterated form in 11.3% of patients, the nonicteric form in 45.5% of patients and the asymptomatic form in 20.5% of patients), are presented. The study revealed that the shedding of HA virus occurred at an early stage (5-10 before a rise in alanine aminotransferase activity in the blood was registered), its excretion lasted for a short time (till jaundice appeared) and no chronic carriership of HA virus was registered. The hospitalization of HA patients after the appearance of jaundice was proved to be unjustified, while measures aimed at the rupture of the fecal-oral mechanism of the transmission of HA virus were shown to have good prospects. The epidemiological features of hepatitis E (HE) are considered. HE cases constituted 2-3.6% of all patients with acute viral hepatitis in Moscow (all these cases were brought from Central Asia). The outbreaks of this infection in the countries of Central Asia were shown to be due to the transmission of the infective agent by the water route. The data on the first results of the use of high-titer specific immunoglobulin for the prophylaxis of HE among 135 pregnant women (only one of these women contacted HE, while in a similar group of women used for control 4 HE cases were registered) are presented.

[The detection of antibodies to the hepatitis C virus and to HBsAg in donors with viral hepatitis and cancerous diseases in the Republic of Moldova]. / Vyiavlenie antitel k virusu gepatita C i HBsAg u donorov, bol'nykh virusnymi gepatitami i onkologicheskimi zabolevaniiami, v Respublike Moldova.

Large-scale and uneven distribution of hepatitis C and B (HC and HB) among free blood donors of different regions of the Moldova Republic was established. The rate of detection of anti-HCV (South 6.2%, North 3.6%) correlated with that of HBsAg detection (south 12.5%, north 4.5%). A great role of HCV in the etiology of acute (among them posttransfusion) hepatitis and chronic hepatitis was demonstrated. A significant frequency of detection of anti-HCV (15%) in children treated in oncohematology wards and receiving multiple hemotransfusions as well as the detected cases of acute posttransfusion HC attest to active realization of this virus transmission in the transfusions of blood and/or its components. The necessity of urgent introduction into the Blood Transfusion Service of the republic of the examination of blood donors for HBsAg, alongside with their examination for the presence of anti-HCV and vaccination prophylaxis of HB in high risk groups is substantiated.

[The clinical manifestations and differential diagnosis of Yersinia hepatitis and viral hepatitis A and B]. / Klinicheskie proiavleniia i differentsial'naia diagnostika iersinioznykh i virusnykh gepatitov A i B.

Hepatic involvement in yersiniosis is associated with clinical symptoms of hepatitis, sometimes dominant in the clinical picture. Such cases need differentiation of yersiniosis with viral hepatitides A and B. Clinical and biochemical findings were compared for matched patients with yersiniosis-induced hepatic lesions, viral hepatitis A and viral hepatitis B verified at specific laboratory examination. This permitted introduction of differential diagnostic signs able to recognize one disease from the other.

[The results of a controlled field trial of a dried erythrocytic immunoglobulin diagnostic agent for detecting the hepatitis A virus antigen]. / Rezul'taty polevogo kontroliruemogo ispytaniia diagnostikuma éritrotsitarnogo immunoglobulinovogo sukhogo dlia vyiavleniia antigena virusa gepatitia A.

The results of the controlled field trial of lyophilized erythrocytic immunoglobulin diagnosticum for the detection of hepatitis A virus antigen in the urine and feces of patients are presented. This diagnosticum was used for the study of urine and fecal samples from 225 patients (of these, 176 had hepatitis A) and 54 healthy persons in the passive hemagglutination (PHA) test. Their blood sera were studied in the PHA test (to detect HBsAg) and the radioimmunoassay (to detect anti-HAV IgM). The immunoglobulin diagnosticum under study was found to be nonspecific and faintly sensitive and, therefore, unsuitable for use in medical practice.

[The chronic course of spontaneous and experimental hepatitis A in rhesus monkeys with viral persistence]. / Khronicheskoe techenie spontannogo i éksperimental'nogo gepatita A u makak rezusov s persistentsiei virusa.

The prolonged (up to 2 years) complex observation of 11 rhesus macaques (Macaca mulatta) with spontaneous hepatitis A and 14 rhesus macaques with experimental hepatitis A developing after their intravenous and/or oral infection with human hepatitis A virus (HAV). Both natural and experimental infection took a chronic course (15-18 months). In 13 monkeys showing morphological changes in the liver during the whole period of the disease elevated enzyme levels in the blood and virus shedding in feces were periodically observed. Only one monkey had acute hepatitis A which lasted 1.5 months. In 11 monkeys the disease took an undulating course with 1-2 relapses when virological, biochemical and morphological signs of the disease could be detected. Seroconversion was observed in all monkeys. Anti-HAV IgM antibodies were retained for not more than 6-7 months and total anti-HAV antibodies, during the whole period of observation. Relapses were found to induce no antibody formation. Evidence on the prolonged (up to 12-16 months) persistence of HAV in primates was obtained for the first time.

[The sensitivity of rhesus and cynomolgus macaques to the human hepatitis A virus]. / Chuvstvitel'nost' makak rezusov i iavanskikh makak k virusu gepatita A cheloveka.

Hepatitis A infection characterized by virus excretion in feces, synthesis of specific IgM antibody, increased activity of alanine aminotransferase in the blood serum, and a complex of morphological lesions in the liver typical of acute hepatitis was reproduced in M. fascicularis (M. f.) and Macaca rhesus (M. r.) using 2 strains of hepatitis A virus (HAV) isolated from human patients. The incubation period varying from 9 to 23 (mean 16) days in M. f. and from 12 to 35 (mean 18) days in M. r. in primary infection shortened to 1-12 (mean 10) and 3-6 (mean 5) days in the process of virus passage from monkey to monkey. The disease was observed to run both manifest forms (except jaundice) typical of human HA and an inapparent form in which the level of enzymes remained within normal limits but HAV could be detected in feces, anti-HAV-IgM in the blood serum, and morphologically acute hepatitis in the liver. Immune electron microscopy of both the initial material and in monkey feces at the levels of all three passages revealed complexes consisting of spherical viral particles 27-29 nm in size coated with antibodies. The immune complexes formed upon addition to the fecal extracts under study of IgG isolated both from human convalescent sera and from sera of experimentally infected monkeys collected in the acute stage of the illness.

[Experimental model of hepatitis A in rhesus monkeys (Macaca mulatta) infected with human hepatitis A virus]. / Eksperimental'naia model' gepatita A na makakakh rezusakh (Macaca mulatta), zarazhennykh virusom gepatita A cheloveka.

The focus of this paper is characterization of Hepatitis A experimental model obtained for the first time in rhesus monkeys (M. mulatta) infected with fecal isolate from a patient with Hepatitis A (HAV-H1). Monkeys were susceptible to oral and intravenous routes of HAV inoculation. The disease could be reproduced regularly in 4 passages as a result of which HAV strain continuously pathogenic for M. mulatta has been established. All 17 infected monkeys developed Hepatitis A with characteristic (except jaundice) patterns: shedding of virus with the stool, elevations of serum alanine aminotransferase level, appearance of IgM anti-HAV, morphological changes developed in the liver. Our data have demonstrated that the course of experimental Hepatitis A infection in M. mulatta is similar (in many respects) to that observed in man.

[A trial of using immunoglobulins of known specificity for preventing hepatitis A in regions with high epidemic activity]. / Opyt primeneniia immunoglobulinov s izvestnoi spetsifichnost'iu dlia profilaktiki gepatita A v regionakh s vysokoi aktivnost'iu épidemicheskogo protsessa.

The economic effectiveness of immunoglobulin prophylaxis (IGP), carried out among children aged 1-3 at the beginning of a seasonal rise in hepatitis A (HA) morbidity with high coefficients of protection (80-85%), was directly related to the activity of the epidemic process. Preparations with sufficiently high content of antibodies to HA virus sharply decreased the manifestation of this infection. The detection rate of the manifest forms of the infection among children covered by prophylactic measures in the foci of HA was considerably lower than among children who had not received the preparation. IGP exerted no essential influence on the dynamics of the formation of population immunity. A high share of children aged 3-4 years, seropositive to HA virus (up to 90%), validates the inadvisability of carrying out IGP in older groups of children.

[Specific immunity in preschool children at high risk of infection with hepatitis A virus]. / Spetsificheskii immunitet u detei preshkol'nogo vozrasta v usloviiakh vysokogo riska infitsirovaniia virusom gepatita A.

The dynamics of postinfection immunity to hepatitis A (HA) in preschool children was studied for 2 years in an area with a high activity of the epidemic process. In primary examinations by radioimmunoassay, anti-HAV were found in 82% of the subjects. The degree of the immunity intensity was found to be markedly variable: in 21% of the children the titre of anti-HAV was 1:10, in 28%-1:40, in 37%-1:160, in 14%-1:640. One year later, in the group of children with titres 1:10-1:40 the antibody level increased from 4- to 64-fold in 66% of the subjects. The rate of increase expressed in mean coefficients of antibody rise were the higher the lower the initial anti-HAV titres were. In the children with the initial titre below 1:10 this value approached 100, and anti-HAV-IgM were found in half of the examined subjects, one third of them having experienced the jaundice form of HA. The children with titres of 1:10-1:40 were found to have both manifest (14% and 11%, respectively) and asymptomatic (only anti-HAV-IgM) forms of HA. In the group of children with titres of antibody of 1:160-1:640 neither manifest HA forms nor anti-NAV-IgM could be detected. In this group the anti-HAV titre increased 4-fold or more in only 9% whereas a decrease was observed in 59% (with titre of 1:160) and in 73% (with titre of 640). No changes in anti-HAV levels were observed in 32% and 18%, respectively. Thus, the results of the study indicate that at low levels of postinfection immunity reinfection with HAV is possible and may run both manifest and asymptomatic course.