[Reactivation of Epstein-Barr virus (Herpesviridae: Lymphocryptovirus, HHV-4) infection during COVID-19: epidemiological features].

INTRODUCTION: Immunodeficiency underlying the development of severe forms of new coronavirus infection may be the result of mixed infection with SARS-CoV-2 and other pathogens, including Epstein-Barr virus (EBV).The aim is to study the prevalence and epidemiological features of co-infection with SARS-CoV-2 and EBV. MATERIAL AND METHODS: A cross-sectional randomized study was conducted in Moscow region from March to May 2020. Two groups were examined for EBV-markers: hospital patients (n = 95) treated for SARS-CoV-2 infection and blood donors (n = 92). RESULTS: With equal EBV prevalence the detection of active infection markers in donors (10.9%) was noticeably lower than in SARS-CoV-2 patients (80%). Significant differences in this indicator were also found when patients from subgroups with interstitial pneumonia with the presence (96.6%) and absence (97.2%) of SARS-CoV-2 in the nasopharyngeal smear were compared with the subgroup of patients with mild COVID-19 (43.3%). The average IgG VCA and IgG EBNA positivity coefficients in donor group were higher than in patient group (p < 0.05). Patients with active EBV infection markers were significantly more likely to have pneumonia, exceeding the reference values of ALT and the relative number of monocytes (odds ratio - 23.6; 3.5; 9.7, respectively). DISCUSSION: The present study examined the incidence and analyzed epidemiological features of active EBV infection in patients with COVID-19. CONCLUSION: A significantly higher rate of detection of active EBV infection markers in hospital patients indicates a combined participation SARS-CoV-2 and EBV in the development of interstitial pneumonia. Low levels of specific IgG EBV serve as predictors of EBV reactivation. Exceeding the reference values of ALT and the relative number of monocytes in patients should serve as a reason for examination for active EBV infection markers.

[ANALYSIS OF EFFECTIVENESS OF USINGJIgY FROM CHICKEN IN SANDWICH METHOD OF HBsAg TESTING].

AIM: Study antigen-binding ability of polyclonal antibodies (PCA) of chicken compared with monoclonal -antibodies (MCA) of mice in the model of interaction with HBsAg. MATERIALS AND METHODS: Mice MCA 18C8 and MKA F3/F4 (IgG) were used, effective in enzyme immunoassay sandwich method of HBsAg determination (with a minimal detection dose of 0.017 ng/ml), and affinity purified anti-HBsAg PCA of chicken (IgY), obtained from 2 immunized birds (PCA No. 1 and PCA No. 2). The ability of antibodies to bind HBsAg was evaluated by analytical sensitivity (slope of binding curve) of solid-phase enzyme immunoassay system using mice MCA and chicken PCA. RESULTS: PCA No. 2 has provided a statistically significant 40% increase of analytical sensitivity, compared with <

[Effect of pH of Adsorption Buffers on the Number and Antigen-Binding Activity of Monoclonal Antibodies Immobilized on the Surface of Polystyrene Microplates].

The change in the concentration and antigen-binding activity of 28 monoclonal antibodies was studied after their adsorption on the surface of polystyrene microplates in buffers with different pH values (1.0, 2.8, 7.5, 9.6, and 11.9). We used 16 clones to the HIV p24 protein and 12 clones to the surface antigen of Hepatitis B Virus. The binding efficiency of adsorbed antibodies to the labeled antigen was evaluated by the slope of the linear region of the binding curve to the concentration axis. It was shown that the antigen-binding activity of six antibodies (21.5%) statistically significantly increased after adsorption at pH 2.8 and 11.9 as compared to pH 7.5 and 9.5. The maximum amount of antibodies was found to be adsorbed on the solid surface at pH 7.5. The analysis of the binding of 125I-HBs-antigen to adsorbed antibodies made it possible to evaluate the concentration of active antibodies on the polystyrene surface. It was shown that the increase in the antigen-binding activity was due to an increase in the proportion of antibodies with retained activity after adsorption at pH 2.8 and 11.9. Under these conditions, about 20% of the antibodies retained their antigen-binding activity, and 6% did so after immobilization at pH 7.5.

[EFFECTIVENESS OF PREVENTIVE VACCINE PROPHYLAXIS OF CHICKEN POX IN MILITARY COLLECTIVES].

AIM: Study the effectiveness of preventive vaccine prophylaxis of chicken pox in military collectives. MATERIALS AND METHODS: In the focus of chicken pox, 200 servicemen of the new addition by conscription were immunized once against chicken pox; 97 servicemen by conscription of the new addition (comparison group) were not vaccinated. Epidemiologic and immunologic effectiveness of conduction of preventive vaccine prophylaxis in chicken pox focus were studied. RESULTS: In the group of 200 soldiers, that were present in the focus of infection and were immunized once against chicken pox, only 2 cases of this disease were registered (10 per thousand). In the comparison group, that consisted of 97 unvaccinated servicemen, chicken pox disease was registered in 7 individuals (72 per thousand). Epidemiologic effectiveness of preventive vaccine prophylaxis of chicken pox amounted to 86%. Immunologic effectiveness of vaccination 2-3 weeks after the immunization was 42%, and 2 months after--44%. Local reactions in the form of hyperemia (up to 1.5 cm) and edema were noted in 10% of the vaccinated at the location of preparation administration; in 1.7%--general reaction in the form of temperature increase to 37.8°C was observed. Post-vaccinal complications in the immunized group were not detected. CONCLUSION: Preventive vaccination of servicemen allows to minimize the spread of chicken pox, however can not serve as means of complete elimination of the infection from military collectives.

[VARICELLA ZOSTER VIRUS AND DISEASES OF CENTRAL NERVOUS SYSTEM VESSELS].

Systemized data on epidemiology, pathogenesis, clinical manifestation, diagnostics and therapy of VZV-vasculopathy--a disease, occurring due to damage of arteries of the central nervous system by Varicella Zoster virus, are presented in the review. A special attention in the paper is given to the effect of vaccine prophylaxis of chicken pox and herpes zoster on the frequency of development and course of VZV-vasculopathy.

[Comparative evaluation of effectiveness of traditional serologic and modified methods of herpes zoster laboratory diagnostics].

AIM: Comparative evaluation of effectiveness of traditional serologic and modified diagnostic methods of disease arising due to varicella and herpes zoster virus (VZV) reactivation. MATERIALS AND METHODS: 2 groups of patients were examined. The main group consisted of 39 patients with manifest form of herpes zoster (HZ), control--20 healthy donors. Sex composition of the groups did not differ. Traditional method of serologic diagnostics included determination of anti-gE VZV IgG and anti-VZV IgG and anti-IgM in patient and donor blood sera by using EIA. Modified methods consisted of isolation in density gradient and cultivation for 48 hours of peripheral blood mononuclears (PBMC) in RPMI-1640 complete culture medium containing 10% of fetal bovine serum, 4 mM L-glutamin and gentamycin. Concentrations ofanti-VZV IgG and IgM were then determined in culture medium by using EIA. RESULTS: In all the examined HZ patients and healthy donors anti-VZV IgG were detected in blood. Only in 26 (67%) of 39 HZ patients anti-gE VZV IgG and anti-VZV IgM were determined in blood sera. Among donors false positive results for these markers were detected in 10% and 5% of cases, respectively. During simultaneous determination of anti-gE VZV IgG and anti-VZV IgM the specificity of the method increased to 100%, sensitivity of the diagnostic method based on simultaneous determination of anti-gE VZV IgG and anti-VZV IgM was 59%. During analysis of spontaneous production of anti-VZV antibodies by PBMC in 38 (97.4%) of 39 patients anti-VZV IgG were determined in PBMC culture, anti-VZV IgM production was observed only in 4 patients. In control group false positive results of anti-VZV IgG and IgM production by PBMC was not detected by the modified method (100% specificity). At equal specificity level sensitivity of the modified method based on determination of spontaneous anti-VZV IgG production by PBMC culture was significantly higher than effectiveness of the traditional serologic diagnostics (97.4% and 59%, p < 0.0001). CONCLUSION: The data obtained allow to recommend during diagnostics of manifest and atypical VZV infection forms arising due to endogenous virus reactivation the new modified method of laboratory diagnostics of the disease as having higher sensitivity compared with traditional serologic method.

[Effect of conditions of monoclonal antibody adsorption on antigen-binding activity].

The dependence of the antigen-binding activity of immobilized antibodies on pH of a saturating buffer has been investigated. We analyzed 28 monoclonal antibodies (MCAs) produced by various hybridomas to three virus antigens, i.e., the nuclear p23 protein of hepatitis C virus (C core protein p23), p24 protein of HIV 1, and the surface antigen of hepatitis B virus (HBsAg). Antibodies were adsorbed on the surfaces of immune plates in acidic (pH 2.8), neutral (pH 7.5), and alkaline (pH 9.5) buffers. The binding of labeled antigens, i.e., biotinylated or conjugated with horseradish peroxidase, with immobilized antigens was tested. It was shown that 10 out of 28 analyzed MCAs (36%) considerably better preserved their antigen-binding activity if their passive adsorption was carried out on the surface of polystyrene plates in an acidic buffer (pH 2.8). This approach allowed constructing a highly sensitive sandwich method for HBsAg assay with a minimal reliably determined antigen concentration of 0.013-0.017 ng/ml. The described approach may be recommended for the optimization of sandwich methods and solid-phase competitive methods.

[Heterogeneity of hepatitis B virus and diagnostic potential of modern test systems for the detection of HBsAg].

AIM: Study heterogeneity ofhepatitis B virus in adult patients with chronic hepatitis B and determination of diagnostic potential of modern test systems with the detection of HBsAg with amino acid substitutions in the main hydrophilic region (MHR). MATERIALS AND METHODS: In 27 hepatitis B virus samples isolated from patients with chronic hepatitis B virus infection living in Vladimir, nucleotide sequence ofgenome region corresponding to preS1/preS2/S genes was determined. RESULTS: In all of the 27 isolates genotype D virus presented by 3 subgenotypes D1, D2, D3 was detected in 18%, 26% and 56% respectively. Based on the distribution of nucleotide substitutions in the compared functional regions of hepatitis B virus (virus entry into the cell coding site (2875 - 2991 n.b.), pre-S2/S promoter region (2994 - 3171 n.b.), 5'-end pre-S2 and S-genes sequences (3172 - 154 n.b. and 155-455 n.b.), MHR (455 - 635 n.b.) and 3'-end S-gene sequence (636 - 835 n.b.), substitutions are mostly concentrated in the promoter region of the S2/S-genes (30.8%). HBsAg serotypes were determined in 24 of 27 cases by using the predicted amino acid sequence, and in 17 cases HBsAg belonged to ayw2 (71%) serotype and in 7 cases - to ayw3 serotype (29%). Amino acid substitutions G145A, M133I, S132T localized in the main hydrophilic region and P217L, S207N, V184A localized in the C-end of the protein C that are connected with diagnostic and vaccine escape were identified in 5 isolates. CONCLUSION: Diagnostic potential of test systems with the detection of HBsAg with known amino acid sequence of the MHR region were studied. Approximately equal potential of 6 test systems to detect HBsAg with amino acid substitutions G145A, M133I and S132T localized in the MHR region were shown.

[Hepatitis virus genotype structure in patients with chronic hepatitis C].

AIM: Studies of hepatitis C virus (HCV) genotype and subtype structure in patients with chronic hepatitis C in 3 regions of the Central federal district of Russia. MATERIALS AND METHODS: Hepatitis C virus genotype and subtype structure was determined in patients with chronic HCV infection in Moscow (1993 - 1995 and 2005), Moscow region (2008) and Vladimir region (1993 -1995, 2005-2007). HCV genotype was determined by using A. Widell et al. (1994) technique, PCR (AmpliSens diagnostic kits), Genotype C test system. RESULTS: In all studied regions and during all the time periods the first position in rating belonged to HCV 1b subtype. In 1993 - 1995 and 2005 - 2007 period changes in HCV genotype and subtype structure were registered that consisted of relative weight of 1b subtype decrease and 3a subtype increase. Subtype 1b in females with chronic hepatitis C was registered more often than in males. In Vladimir region 3a subtype in males was detected more often than in females. In males older than 30 years the first rating position belongs to 1b subtype and in males younger than 30 years--subtype 3a. In females older than 30 years in Moscow region and Vladimir region, as well as in females younger than 30 years in Vladimir region subtype 1b was detected more often, while in Moscow region HCV subtypes 1b and 3a were detected with the same rate of 47.6%. CONCLUSION: Currently there is an urgent need to include mandatory monitoring of hepatitis C virus genetic variants into the system of hepatitis C epidemiologic control in Russia. This approach will allow for a significant increase in quality of hepatitis C serological diagnostics, and can be used in the prognosis of evolution of the epidemic process of this disease.

[Effects of silver and silicon dioxide nanopowders on the development of herpesvirus infection in vitro].

Estimation of the potential ability of nanoparticles (NP) to affect human health has generated a need for developing rapid, sensitive, and efficient laboratory tests of the toxicity of nanomaterials. The purpose of the investigation was to study the cytotoxic effect of NP of silver (Ag) and silicon dioxide (SiO2). The transplantable Vero cells treated with NP at different concentrations were used as target cells. Some experiments examined the combined effects of nanopowders and herpes simplex virus type 2 (HSV-2) on Vero cell viability and the direct effect of NP on the reproductive potential of HSV-2 in the culture. SiO2 NPs at concentrations of 1.0 to 0.1 mg/ml were found to cause a marked cytotoxic effect that was in the complete destruction of the cell monolayer. Ag HPs were more toxic than silicon nanopowders and induced a complete degradation of the cell monolayer at substantially lower concentrations. The results of the study formed the basis for the development of a rapid (24-48-hour), reliable, and efficient test for the toxicity of nanomaterials, by using the cultured cells in the laboratory setting. It was also shown that silicon NPs did not noticeably affect the reproductive potential of HSV-2 while nano silver suppressed the capacity of HSV-2 for multiplication, by significantly reducing viral progeny titer in the cell culture.

[Use of pH-sensitive immobilized monoclonal antibodies for optimization of immunoenzyme sandwich technique of detection of HBsAg of hepatitis B virus].

AIM: To develop highly sensitive sandwich technique for identification of surface hepatitis B virus antigen (HBsAg) in serum and analyse of possible improvement of solid phase for immunoenzyme sandwich technique of HBsAg identification through variation of pH-dependent sorption of monoclonal antibodies on the surface of immune plates. MATERIALS AND METHODS: Calibration curves for identification of HBsAg in sandwich techniques using 36 possible binary combinations of monoclonal antibodies of our panel (including high affinity antibodies to HBsAg produced by 6 hybridomas) were compared. Immobilization of antibodies on solid phase (by passive sorption) was performed at different pH values (2.8, 7.5, and 9.5). RESULTS: Analysis of panel of antibodies to HBsAg produced by 6 hybridomas revealed pH-dependent monoclonal antibodies (18C8), which immobilization at low pH values together with detecting antibodies F4F3 allowed to greatly improve sensitivity of the sandwich technique. Minimal credibly detectable concentration of HBsAg in sera of persons infected with hepatitis B virus was 0.013 - 0.017 ng/ml. Validation of sandwich technique was performed on certified panel of serum samples with various concentrations of HBsAg (different serotypes). CONCLUSION: Highly sensitive sandwich technique for detection of HBsAg was developed. It was shown that analysis of panel of monoclonal antibodies on pH-dependence could be used as simple methodical approach for optimization of immunoenzyme sandwich techniques for detection of different antigens.

[Changes of expression levels of innate immunity signaling receptors during Candida albicans infections in vitro and in vivo].

AIM: To study levels of expression of Toll-like receptors genes in response to Candida albicans antigens in vitro (using Vero cell line as well as mononuclear cells) and in vivo (using cervical canal cells of pregnant women). MATERIALS AND METHODS: Test-systems for measurement of expression levels of such genes as TLR 1, TLR2, TLR6 as well as system for quantitative measurement of tumor necrosis factor a level, all of which were developed earlier, were used. RESULTS: It was shown that antigens of C. albicans stimulated early increase of expression of innate immunity genes both in studied in vitro models and in cells of cervical canal of pregnant women with candidosis. CONCLUSION: Results of performed study allow to suggest that activation of innate immunity factors resulted from Candida albicans infection.

[Role of Toll-like receptors and defensins in antimicrobial protection of urogenital tract in females].

Levels of expression of hBD-1 gene (beta-defensin 1) and Toll-like receptors (TLR1, TLR2, TLR6) in cells of cervical mucosa in healthy nonpregnant and healthy pregnant women as well as in pregnant women with urogenital infection was measured by developed RT-PCR systems. During normal pregnancy compared with nonpregnant women, increase of TLRs genes expression which was correlated with increase of hBD-1 gene expression was observed. During urogenital infection in pregnant women compared with healthy pregnant, 10- fold and 50-fold increase of TLR1 and TLR2 genes expression respectively was associated with 2.5-fold decrease of hBD-1 gene expression in cervical mucosa. In group of women with untrauterine infection more marked increase of TLRs genes expression was observed. Thus significant changes (TLRs, antimicrobial peptides, cytokines etc.) in cells of cervical mucosa can be used as prognostic criteria for development of intrauterine infection.

[The spread of hepatitis B and C viruses and the structure of HBsAg subtypes in Kabardino-Balkaria].

A seroepidemiological study of the spread of hepatitis B and C viruses (HBV and HCV) was conducted among some population groups in Kabardino-Balkaria. The structure of HBsAg subtypes was also studied in the residents of the republic. The presence of viral hepatitis B markers among the test groups of the healthy population corresponds to the parameters of moderate activity of an epidemic process. The analysis of the immunological structure of the population leads the author to assign Kabardino-Balkaria to highly HBC endemic areas. The occupational factor is demonstrated to be actively involved in the spread of HBC and it is practically of no significance for HCV. An examination could reveal the HBsAg subtype adrq+ that is uncharacteristic of this area.

[Natural immunity and herpes infection].

The review details natural immunological factors that are the first-line protection from herpes simplex virus. These reactions may be conventionally divided into 3 active phases. In Phase 1, the virus is attacked by proteins, such as complement of precursors of natural class M (IgM) antibodies and antimicrobial peptides. In Phase 2, the interferons produced by infected epithelial and resident dendritic cells go into action. And, finally, in Phase 3, effector cells, such as neutrophils, macrophages, and natural killer cells, show antiviral activity.

[In vitro inhibition of the cytopathic action of herpes simplex virus, type 1, with a natural cytokine complex].

The antiviral action of a natural cytokine complex (NCC)--the preparation Superlymph and its peptide antimicrobial fraction (AMF)--in the culture of Vero cells infected with type 1 herpes simplex virus (HSV-1), strain VR-3, was studied. The NCC preparation did not alter the morphology of the cells for 6 days and was not toxic for the culture of Vero cells. The NCC and AMF produced a protective antiviral effect, which was manifested by the inhibition of the cytopathic action (CPA) of the virus. In the presence of the preparation, the CPA of HSV-1 was equal to 10(-4.67) ICPD50, while in the control CPA was equal to 10(-5.60). The fraction containing antimicrobial peptides (protegrins) and isolated from NCC, characterized by the method of mass spectrometry, produced the maximum antiviral effect on the cell strain Vero (10(-4.58) ICPD50). Thus Superlymph, an immunomodulator with antiviral activity, could be regarded as an effective preparation for the treatment of HSV infection. The action of such preparation was aimed at the inhibition of the CPA of the virus and the stimulation of the antiviral protective mechanisms of the cell.

[Morbidity in acute virus hepatitis B on the territory of Kabardin-Balkaria].

Morbidity in acute virus hepatitis B (AVHB) in Kabardin-Balkaria during the period of 1992 to 2003 was analyzed. The dynamics of changes in the age groups of AVHB patients, as well as in the structure of the transmission routes of the disease, was analyzed. The level of AVHB morbidity in the Kabardin-Balkar Republic was lower in recent years than the average level of such morbidity in the whole of Russia. The sharply defined irregularity in the territorial distribution of AVHB cases was established. The highest morbidity rates in AVHB were registered in Nalchik, as well as in Chegem and Prokhladnensk regions. The leading role in the formation of the morbidity in acute virus hepatitis B on the territory of Kabardin-Balkaria belongs to Nalchik, where 56.8% of AVHB cases were registered. In the structure of the transmission routes of AVHB the prevalence of artificial paths was noted; among them, the highest proportion belonged to parenteral medical manipulations in outpatient clinics (32.9%). The proportion of AVHB cases associated with the intravenous use of drugs was 6.9%. In the age structure of AVHB patients adults prevailed, and among them the highest number of cases was registered in the age groups of 20 - 29 years and 30 - 39 years. In 2002 the total proportion of AVHB cases among the patients of these age groups reached 68.3%.

[Enzyme immunoassay system for the detection of low-avid lgG antibodies to human cytomegalovirus ("CMV-diagnost")].

The new Russian enzyme immunoassay system "CMV-Diagnost" based on the detection of low-avid IgG antibodies has been developed for the rapid diagnosis of cytomegalovirus infection. The system was found not only to determine the strained immunity in response to cytomegalovirus, but also to judge the current infection from the avidity index of detectable IgG antibodies with a high degree of validity. The antibody avidity index of less than 30% suggests an acute stage of primary cytomegalovirus infection. The minimum antibody threshold bodies (deltaOD has been established for the correct interpretation of data on low-avid antibodies. deltaOD of > or =0.6 optic units was for the developed test system "CMV-Diagnost. A correlation was found between the serum levels of low-avid antibodies and IgM antibodies to cytomegalovirus at the acute stage of the disease.

[A comparative evaluation of detection of antibodies to hepatitis C virus in different immunoassay test system and verification tests]. / Sravnitel'naia otsenka rezul'tatov opredeleniia antitel k virusu gepatita C pri ispol'zovanii razlichnykh immunofermentnykh test-sistem i podtverzhdaiushchikh testov.

Control tests and subsequent comparative analysis of their results related with the detection of anti-hepatitis C virus (anti-HCV) by different ELISA systems were made at a laboratory of the "Vector-Best" Company, Novosibirsk (A), a clinical diagnostic laboratory of Infection Clinical Hospital No. 1, No. 1 (B), and at a laboratory of chronic viral infections of Andjaparidze Institute of Viral Drugs of the Russian Academy of Medical Sciences (C). Two thousand three hundred and fifty blood sera of donors and 236 blood sera of patients with acute and chronic renal pathology were examined. The comparative research made at the above facilities by different ELISA systems produced diversified results. An analysis of 2350 blood samples from donors made in 3 ELISA systems at laboratory A showed divergence in 19 (0.8%) cases. At laboratories B and C, 5 ELISA systems (a set of 236 samples) denoted differences in 28 (11.9%) cases. Significant variances were registered in confirmation of disputable results of ELISA with immunoblot, which is apparently related with differing criteria applicable to confirming the positive results from using the confirmative tests. A possibility is discussed of using different ELISA systems in screening examination.

[Detection of low avidity IgG as a promising approach to diagnosis of primary herpetic infection]. / Vyiavleniie nizkoavidnykh IgG-antitel--perspektivnyi podkhod v diagnostike pervichnoi gerpeticheskoi infektsii.

A Russian immune-enzyme test-system ("HERPES-DIAGNOST") was designed on the basis of detection of low-avidity IgG antibodies in order to promote the laboratory value of serological examinations of patients with different clinical manifestations of the herpetic infection. The key test parameters were tuned; the immunosorbent production based on antigens (herpes simplex virus--HSV), types 1 and 2, was optimized; and the concentration was chosen for the main reagent that removes the low-avidity antibodies (8 M urea solution) and, finally, the temporal and temperature regimes were selected for testing. A system was elaborated for registering and interpreting the results. The avidity index of antibodies lower than 35% was found to be a reliable criterion confirming the presence of acute primary infection triggered both by HSV-1 and by HSV-2. If there is a relapse of herpetic infection, the avidity index of antibodies can range from 30 to 45%.