COVID-19 Incidence Proportion as a Function of Regional Testing Strategy, Vaccination Coverage, and Vaccine Type

Introduction: The COVID-19 pandemic has become a serious challenge for humanity almost everywhere globally. Despite active vaccination around the world, the incidence proportion in different countries varies significantly as of May 2022. The reason may be a combination of demographic, immunological, and epidemiological factors. The purpose of this study was to analyze possible relationships between COVID-19 incidence proportion in the population and the types of SARS-CoV-2 vaccines used in different countries globally, taking into account demographic and epidemiological factors. Materials and methods: An initial database was created of demographic and immunoepidemiological information about the COVID-19 situation in 104 countries collected from published official sources and repository data. The baseline included, for each country, population size and density; SARS-CoV-2 testing coverage; vaccination coverage; incidence proportion; and a list of vaccines that were used, including their relative share among all vaccinations. Subsequently, the initial data set was stratified by population and vaccination coverage. The final data set was subjected to statistical processing both in general and taking into account population testing coverage. Results: After formation of the final data set (including 53 countries), it turned out that reported COVID-19 case numbers correlated most strongly with testing coverage and the proportions of vaccine types used, specifically, mRNA (V1); vector (V2); peptide/protein (V3); and whole-virion/inactivated (V4). Due to the fact that an inverse correlation was found between 'reported COVID-19 case numbers' with V2, V3, and V4, these three vaccine types were also combined into one analytic group, 'non-mRNA group' vaccines (Vnmg). When the relationship between vaccine type and incidence proportion was examined, minimum incidence proportion was noted at V1:Vnmg ratios (%:%) from 0:100 to 30:70. Maximum incidence proportion was seen with V1:Vnmg from 80:20 to 100:0. On the other hand, we have shown that the number of reported COVID-19 cases in different countries largely depends on testing coverage. To offset this factor, countries with low and extremely high levels of testing were excluded from the data set; it was then confirmed that the largest number of reported COVID-19 cases occurred in countries with a dominance of V1 vaccines. The fewest reported cases were seen in countries with a dominance of Vnmg vaccines. Conclusion: In this paper, we have shown for the first time that the level of reported COVID-19 incidence proportion depends not only on SARS-CoV-2 testing and vaccination coverage, which is quite logical, but probably also on the vaccine types used. With the same vaccination level and testing coverage, those countries that predominantly use vector and whole-virion vaccines feature incidence proportion that is significantly lower than countries that predominantly use mRNA vaccines.

HIV Drug Resistance Mutations and Subtype Profiles among Pregnant Women of Ho Chi Minh City, South Vietnam

According to the latest data released by UNAIDS, the global number of people living with HIV (PLHIV) in 2021 was 38.4 million, with 1.5 million new HIV infections. In different countries, a significant proportion of these cases occur in the adult fertile population aged 15-49 years. According to UNAIDS, Vietnam had a national HIV prevalence of 0.3% of the total population at the end of 2019, with approximately 230,000 PLHIV. The most effective way to prevent mother-to-child transmission of HIV is ART to reduce maternal viral load. HIV-infected pregnant women should undergo monthly monitoring, especially before the expected date of delivery. The aim of our work was to analyze subtypic structure and drug-resistant variants of HIV in pregnant women in Ho Chi Minh City. The study material was blood plasma samples from HIV-infected pregnant women: 31 women showed virological failure of ART, and 30 women had not previously received therapy. HIV-1 genotyping and mutation detection were performed based on analysis of the nucleotide sequences of the pol gene region. More than 98% of sequences genotyped as HIV-1 sub-subtype CRF01_AE. When assessing the occurrence of drug resistance mutations, genetic resistance to any drug was detected in 74.41% (95% CI: 62.71-85.54%) of patients. These included resistance mutations to protease inhibitors in 60.66% (95% CI: 47.31-72.93%) of patients, to NRTIs in 8.20% (95% CI: 2.72-18.10%), and to NNRTIs in 44.26% (95% CI: 31.55-57.52%). Mutations associated with NRTI (2) and NNRTI (8) resistance as well as PI mutations (12), including minor ones, were identified. The high prevalence of drug resistance mutations found in this study among pregnant women, both in therapeutically naive individuals and in patients with virological failure of ART, indicates that currently used regimens in Vietnam are insufficient to prevent vertical HIV infection.

Macrophage-Derived Chemokine MDC/CCL22: An Ambiguous Finding in COVID-19

Macrophage-derived chemokine (MDC/CCL22) is a chemokine of the C-C subfamily. It is involved in T-cellular maturation and migration. Our previous research shows that plasma CCL22/MDC tends to show a statistically significant depletion of concentrations in acute patients and convalescents when compared to healthy donors. In the current work, we investigate existing views on MDC/CCL22 dynamics in association with various pathologies, including respiratory diseases and, specifically, COVID-19. Additionally, we present our explanations for the observed decrease in MDC/CCL22 concentrations in COVID-19. The first hypothesis we provide implies that viral products bind to MDC/CCL22 and block its activity. Another explanation for this phenomenon is based on dendritic cells population and the inhibition of their function.

[Frequency of drug resistance and immune escape mutations in the hepatitis B virus genome detected in pregnant women in the Republic of Guinea]

The aim of the work is to assess the prevalence of hepatitis B virus drug resistance mutations and immune escape mutations in pregnant women in the Republic of Guinea.

MATERIALS AND METHODS

Blood plasma samples obtained from 480 pregnant women from different regions of the Republic of Guinea with laboratory-confirmed viral hepatitis B were studied. Nucleotide sequences for genotype identification and mutation detection were obtained using nested-PCR followed by Sanger sequencing, based on overlapping pairs of primers spanning the complete genome of the virus.

RESULTS AND DISCUSSION

In the examined group, the viral genotype E was the most prevalent (92.92%) compared with subgenotypes A1 (1.67%), A3 (1.46%), D1 (0.63%), D2 (1.04%) and D3 (2.29%). Among the examined HBV-infected pregnant women, 188 (39.17%) had undetectable HBsAg. Drug resistance mutations were detected in 33 individuals, which amounted to 6.88%. The following mutations were found: S78T (27.27%), L80I (24.24%), S202I (15.15%), M204I/V (42.42%). The presence of polymorphic variants not described as drug resistant has also been shown in positions associated with the development of drug resistance to tenofovir, lamivudine, telbivudine and entecavir (L80F, S202I, M204R). When analyzing the MHR and the region of a determinant, mutations were detected in 318 (66.25%) of pregnant women. In 172 of them, which amounted to 54.09%, multiple mutations were found. The amino acid substitutions in 13 positions associated with HBsAg-negative hepatitis B and/or potentially affecting HBsAg antigenicity were identified.

CONCLUSION

The high prevalence of immune escape and drug resistance mutations potentially associated with false-negative result of HBsAg screening, prophylaxis failure, and virological failure of therapy that has been identified among treatment naive pregnant women imposes a serious problem.

SARS-CoV-2 collective immunity among the population of the Republic of Armenia

Background. The COVID-19 pandemic has become a substantial global health crisis, unparalleled in world history. Infection dynamics can have specific characteristics in different countries due to social, economic, climatic, or geographic factors. Aim: to study features of SARS-CoV-2 collective immunity among the Armenian population. Materials and methods. A cross-sectional, randomized study of collective immunity was carried out according to a program developed by Rospotrebnadzor and the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The study was approved by the ethics committees of the National Center for Infectious Diseases (Armenia) and the St. Petersburg Pasteur Institute (Russia). A volunteer cohort was formed (N = 6057), randomized by age and region. The studys analysis included: shares and distributions of antibodies (Abs) to nucleocapsid (Nc) antigen (Ag) and receptor binding domain (RBD) S-1 Ag in the cohort; and quantitative determination of these Abs by ELISA. During the survey, a history of vaccination was indicated by 4395 people. Results. Overall seropositivity formed in the whole cohort (by April 14, 2022) was 98.6% (95% CI: 98.198.7). It did not depend on age, place of residence, or occupation. When quantifying Nc and RBD Abs, the proportions of volunteers with Nc Ab levels of 117 BAU/ml and RBD Ab levels of 22.6220 BAU/ml were the smallest, amounting to 6.9% (95% CI: 6.27.5) and 20.4% (95% CI: 19.421.4), respectively. With increasing serum concentrations (Nc 667 BAU/ml, RBD 450 BAU/ml), the proportions of individuals with the corresponding levels were 20.2% for Nc (95% CI: 19.221.3) and 54.2% for RBD (95% CI: 52.955.5). Vaccination coverage was 72.6% (95% CI: 71.573.7). The most frequently used were Sinopharm/BIBP (32.4%), AZD1222 (22.3%), and Gam-COVID-Vac (21%). The remaining vaccines (CoronaVac, mRNA-1273, BNT162b2, CoviVac) were used by 24.3% of vaccinated individuals. When summing vaccines by platform, it was found that: vector vaccines were used in 40.34% (95% CI: 33.5742.39) of cases; whole-virion vaccines were used in 26.83% (95% CI: 24.7632.20); and vector vaccines were used in 6.33% (95% CI: 4.848.91). Conclusion. The epidemic situation in Armenia by April 2022 was characterized by a high level of collective immunity, independent of age or regional factors. Vector and whole-virion vaccines have been used most widely.

ATR-FTIR spectrum analysis of plasma samples for rapid identification of recovered COVID-19 individuals

The development of fast, cheap and reliable methods to determine seroconversion against infectious agents is of great practical importance. In the context of the COVID-19 pandemic, an important issue is to study the rate of formation of the immune layer in the population of different regions, as well as the study of the formation of post-vaccination immunity in individuals after vaccination. Currently, the main method for this kind of research is enzyme immunoassay (ELISA, enzyme-linked immunosorbent assay). This technique is sufficiently sensitive and specific, but it requires significant time and material costs. We investigated the applicability of attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy associated with machine learning in blood plasma to detect seroconversion against SARS-CoV-2. The study included samples of 60 patients. Clear spectral differences in plasma samples from recovered COVID-19 patients and conditionally healthy donors were identified using multivariate and statistical analysis. The results showed that ATR-FTIR spectroscopy, combined with principal components analysis (PCA) and linear discriminant analysis (LDA) or artificial neural network (ANN), made it possible to efficiently identify specimens from recovered COVID-19 patients. We built classification models based on PCA associated with LDA and ANN. Our analysis led to 87% accuracy for PCA-LDA model and 91% accuracy for ANN, respectively. Based on this proof-of-concept study, we believe this method could offer a simple, label-free, cost-effective tool for detecting seroconversion against SARS-CoV-2. This approach could be used as an alternative to ELISA.

Prevalence of HIV and Viral Hepatitis Markers among Healthcare Workers in the Republic of Guinea

Healthcare workers are much more likely to be infected with HIV and hepatitis viruses compared to the general population. Although healthcare workers are more aware of HIV and hepatitis viruses, several countries in Africa lack a comprehensive grasp of disease routes and transmission risks. The aim of this study was to assess the prevalence of the serological and molecular biological markers of HIV and viral hepatitis among healthcare workers in the Republic of Guinea. The study material was 74 blood serum samples collected from healthcare workers who received additional training at the Institute of Applied Biological Research of Guinea (IRBAG, Kindia, Republic of Guinea). The markers examined included HBsAg, HBeAg, anti-HBs IgG, anti-HBcore IgG, anti-HCV qualitative determination, anti-HEV IgM and IgG, anti-HAV IgM and IgG, and anti-HIV. For viral DNA and RNA detection, nucleic acids were extracted from blood serum, and viral presence was inferred using real-time PCR with hybridization fluorescence detection. A high prevalence of viral hepatitis B markers was shown, and significantly fewer cases of viral hepatitis C and HIV were detected. Almost all examined medical workers had anti-HAV IgG antibodies, but no antibodies to hepatitis E virus. Apparently, the identified markers depend on the general prevalence of certain pathogens in the region and are associated with the traditions and characteristics of the country's residents.

Molecular and genetic characterization of the hepatitis B virus full-length genome sequences identified in HBsAg-negative blood donors in Ural Federal District

Introduction. The World Health Organization estimates that as of 2019, more than 296 million people were living with chronic hepatitis B virus (HBV) infection. The prevalence of HBsAg-negative, occult form of the disease in blood donors varies depending on the region of the world and the sensitivity of the methods of analysis used. Considering that the genetic diversity of viruses demonstrates space and time variations and taking into account that the genetic profile of isolates in key groups, which may turn into a source of the pathogen spread, is important for forecasting of the epidemiological situation, the attention should be given to identification of HBV genotypes currently circulating among regular blood donors in regions of the Russian Federation. The aim of this work was molecular and genetic characterization of HBV genomes identified in HBsAg-negative blood donors in the Ural Federal District. Materials and methods. The study material was 1400 plasma samples obtained from HBsAg-negative blood donors in Ural Federal District. The study included the testing for HBsAg, anti-HBs IgG and anti-HBcore IgG antibodies, HBV DNA. For all identified HBV DNA containing samples, sequencing and analysis of the nucleotide sequences of the complete HBV genomes were performed. Results. The prevalence of HBV DNA was 4.93%, including 4 (0.28%) cases of false occult hepatitis B. Among anti-HBcore IgG-positive samples, HBV DNA was found in 18.08% of cases, while in persons with detected HBV DNA the anti-HBcore IgG positivity rate was 46.38%. In 8.69% of the isolates, anti-HBs IgG antibodies and viral DNA were detected simultaneously in the absence of anti-HBcore IgG. Based on phylogenetic analysis, HBV subgenotypes distribution in HBsAg-negative blood donors was as follows: D3 53.62%, D2 21.74%, D1 18.84%, C2 5.8%. The high variability in the S, C, P regions of the virus genome in the examined group was shown. In all cases of HBsAg-negative chronic HBV infection identified in blood donors, viral sequences contained at least one amino acid substitution in positions, mutations in which are associated with immune escape. In 3 (4.35%) cases mutations in reverse transcriptase region of P gene that are associated with resistance to the following drugs were identified: lamivudine, telbivudine, entecavir. Mutations in the preCore/Core regions that contribute to the progression of liver disease were also identified. Conclusion. Occult HBsAg-negative chronic HBV infection poses a threat of HBV transmission through transfusion of blood and its components due to the extremely low viral load, which does not allow the virus to be detected using routinely used diagnostic kits. The situation can be exacerbated by the abundance and diversity of virus amino acid substitutions that we have identified, including immune escape mutations, drug resistance mutations, and mutations that contribute to the progression of the disease.

Prevalence of drug resistant HIV-1 forms in patients without any history of antiretroviral therapy in the Republic of Guinea

To study the structure of human immunodeficiency virus (HIV)-1 drug resistance (DR) in patients with newly diagnosed infection. Residents of the Republic of Guinea (N = 2168) were tested for HIV using enzyme-linked immunosorbent assay (ELISA). Individuals with a positive result were further examined for the presence of viral load in blood plasma. HIV was analyzed using Sanger sequencing. The obtained sequences were genotyped using REGA (version 3.0) and analyzed in MEGA 7. Analysis for the presence of DR mutations was performed using the Stanford University HIV DR Database. Serological markers of HIV were detected in 239 people, which represents 11.02% of the entire sample. HIV RNA was detected in 58 people. The following subtypes were seen: HIV CRF02_AG (41.9%); A1 (29.1%); A3 (12.9%); URF A1_G (12.9%); and G (3.2%). In 25% of patients, at least one significant mutation was encountered leading directly to HIV DR. The mutations encountered cause resistance to NRTI and NNRTI; one case of multiple resistance was identified. Major resistance to protease inhibitor was not seen. The detection of HIV-1 mutations associated with DR, in individuals who have never received antiretroviral therapy, is a cause for concern. It suggests that: new infections are occurring with strains that already have resistance; and the expansion of resistance is not always directly associated with selective drug pressure. Among the likely reasons for the high prevalence of primary HIV DR in the Republic of Guinea, drug availability is probably the key. The consequence of this is the lack of adherence of patients to treatment, the formation and transmission of resistant variants of the virus in the population. These findings suggest the need to test patients for resistant virus variants before initiating treatment.

Method for hepatitis B virus DNA detecting in biological material at low viral load based on nested PCR with detection on three viral targets in real-time mode

A method has been developed for HBV DNA finding in biological material at low viral load based on nested PCR with real-time detection of three viral targets. When developing the method, blood plasma samples were used from 128 CHB patients living in the regions of the Russian Federation and countries of Central Asia and 173 hemodialysis center patients living in the North-West Federal District. Analytical sensitivity was tested using the stepwise dilution method. HBV was detected by nested PCR. According to the method developed by us, at the first stage, the HBV DNA is amplified using at the first stage oligonucleotides complementary to the greatest similarity regions of the various HBV isolates genomes flanking the entire virus genome. At the second stage, when using the amplification product of the first stage as a template, PCR was performed using three pairs of oligonucleotides and the corresponding oligonucleotide fluorescently labeled probes to three virus genome regions (Core gene, S gene and X gene), as well as one pair of primers and the corresponding probe complementary to a human HPRT gene region. The method sensitivity for DNA extraction from plasma with a 100 μl volume was 10 IU/ml. Obtaining a threshold Ct cycle for only one fluorophore may indicate the presence of HBV DNA in the sample at a load of less than 10 IU/ml, HBV detection in this case is possible with a repeated PCR study of the corresponding sample with HBV DNA extraction from an increased plasma volume (200-1000 μl). The developed method makes it possible to identify the disease in various HBV subgenotypes and can be used to diagnose CHB in the population and risk groups, including those with the HBsAg-negative form of the disease.

[Genetic diversity of the human immunodeficiency virus (HIV-1) in the Kaliningrad region]

INTRODUCTION

As is currently known, the epidemic process in the Kaliningrad Region was mainly associated with the spread of the recombinant form of HIV-1 (CRF03_AB); however, regular HIV importations from other countries and continents has created favorable conditions for emergence and spread of various recombinant forms of the virus.The most complete information on the diversity of recombinant forms in the region is also necessary to understand the structure of drug resistance (DR). The aim of the study was to explore the HIV-1 genetic diversity in the Kaliningrad Region.

MATERIALS AND METHODS

We studied 162 blood plasma samples obtained from patients from the Kaliningrad Region, both with confirmed virological failure of antiretroviral therapy (ART) and with newly diagnosed HIV infection. For reverse transcription and amplification of HIV genome fragments, diagnostic «AmpliSense HIVResist-Seq».

RESULTS AND DISCUSSION

The various recombinants between subtypes A and B (74%) were predominant in study group: recombinant was between CRF03_AB and subtype A (33.95%) and CRF03_AB-like (13.58%) were the most common. Among the "pure" subtypes of the virus, subtype A6 (16.67%). The circulation of subtypes B (3.70%) and G (1.23%) was also noted.Ninety-six patients (59.26%) were identified with at least one mutation associated with antiretroviral (ARV) drug resistance.

CONCLUSION

The observed diversity of subtypes and recombinant forms of the virus implies that the new recombinants are actively emerging in the studied region, both between existing recombinant forms and "pure" subtypes, as well as between "pure" subtypes.

Heterogenous CD8+ T Cell Maturation and 'Polarization' in Acute and Convalescent COVID-19 Patients

BACKGROUND

The adaptive antiviral immune response requires interaction between CD8+ T cells, dendritic cells, and Th1 cells for controlling SARS-CoV-2 infection, but the data regarding the role of CD8+ T cells in the acute phase of COVID-19 and post-COVID-19 syndrome are still limited.

METHODS

. Peripheral blood samples collected from patients with acute COVID-19 (n = 71), convalescent subjects bearing serum SARS-CoV-2 N-protein-specific IgG antibodies (n = 51), and healthy volunteers with no detectable antibodies to any SARS-CoV-2 proteins (HC, n = 46) were analyzed using 10-color flow cytometry.

RESULTS

Patients with acute COVID-19 vs. HC and COVID-19 convalescents showed decreased absolute numbers of CD8+ T cells, whereas the frequency of CM and TEMRA CD8+ T cells in acute COVID-19 vs. HC was elevated. COVID-19 convalescents vs. HC had increased naïve and CM cells, whereas TEMRA cells were decreased compared to HC. Cell-surface CD57 was highly expressed by the majority of CD8+ T cells subsets during acute COVID-19, but convalescents had increased CD57 on 'naïve', CM, EM4, and pE1 2-3 months post-symptom onset. CXCR5 expression was altered in acute and convalescent COVID-19 subjects, whereas the frequencies of CXCR3+ and CCR4+ cells were decreased in both patient groups vs. HC. COVID-19 convalescents had increased CCR6-expressing CD8+ T cells. Moreover, CXCR3+CCR6- Tc1 cells were decreased in patients with acute COVID-19 and COVID-19 convalescents, whereas Tc2 and Tc17 levels were increased compared to HC. Finally, IL-27 negatively correlated with the CCR6+ cells in acute COVID-19 patients.

CONCLUSIONS

We described an abnormal CD8+ T cell profile in COVID-19 convalescents, which resulted in lower frequencies of effector subsets (TEMRA and Tc1), higher senescent state (upregulated CD57 on 'naïve' and memory cells), and higher frequencies of CD8+ T cell subsets expressing lung tissue and mucosal tissue homing molecules (Tc2, Tc17, and Tc17.1). Thus, our data indicate that COVID-19 can impact the long-term CD8+ T cell immune response.

T helper cell subsets and related target cells in acute COVID-19

Current review presents a brief overview of the immune system dysregulation during acute COVID-19 and illustrates the main alterations in peripheral blood CD4+ T-cell (Th) subsets as well as related target cells. Effects of dendritic cell dysfunction induced by SARS-CoV-2 exhibited decreased expression of cell-surface HLA-DR, CCR7 as well as co-stimulatory molecules CD80 and CD86, suggesting reduced antigen presentation, migratory and activation capacities of peripheral blood dendritic cells. SARS-CoV-2-specific Th cells could be detected as early as days 24 post-symptom onset, whereas the prolonged lack of SARS-CoV-2-specific Th cells was associated with severe and/or poor COVID-19 outcome. Firstly, in acute COVID-19 the frequency of Th1 cell was comparable with control levels, but several studies have reported about upregulated inhibitory immune checkpoint receptors and exhaustion-associated molecules (TIM3, PD-1, BTLA, TIGIT etc.) on circulating CD8+ T-cells and NK-cells, whereas the macrophage count was increased in bronchoalveolar lavage (BAL) samples. Next, type 2 immune responses are mediated mainly by Th2 cells, and several studies have revealed a skewing towards dominance of Th2 cell subset in peripheral blood samples from patients with acute COVID-19. Furthermore, the decrease of circulating main Th2 target cells basophiles and eosinophils were associated with severe COVID-19, whereas the lung tissue was enriched with mast cells and relevant mediators released during degranulation. Moreover, the frequency of peripheral blood Th17 cells was closely linked to COVID-19 severity, so that low level of Th17 cells was observed in patients with severe COVID-19, but in BAL the relative number of Th17 cells as well as the concentrations of relevant effector cytokines were dramatically increased. It was shown that severe COVID-19 patients vs. healthy control had higher relative numbers of neutrophils if compared, and the majority of patients with COVID-19 had increased frequency and absolute number of immature neutrophils with altered ROS production. Finally, the frequency of Tfh cells was decreased during acute COVID-19 infection. Elevated count of activated Tfh were found as well as the alterations in Tfh cell subsets characterized by decreased regulatory Tfh1 cell and increased pro-inflammatory Tfh2 as well as Tfh17 cell subsets were revealed. Descriptions of peripheral blood B cells during an acute SARS-CoV-2 infection werev reported as relative B cell lymphopenia with decreased frequency of nave and memory B cell subsets, as well as increased level of CD27hiCD38hiCD24 plasma cell precursors and atypical CD21low B cells. Thus, the emerging evidence suggests that functional alterations occur in all Th cell subsets being linked with loss-of-functions of main Th cell subsets target cells. Furthermore, recovered individuals could suffer from long-term immune dysregulation and other persistent symptoms lasting for many months even after SARS-CoV-2 elimination, a condition referred to as post-acute COVID-19 syndrome.

Longitudinal Randomized Cohort Study of SARS-CoV-2 Antibody Seroprevalence in the St. Petersburg Population

Introduction. Since the detection of the first COVID-19 patient, 2 years have passed, during which more than 287,862,000 people have fallen ill globally, of which about 1.9% died. The implementation of SARS-CoV-2 control programs required efforts from almost all countries. An important direction in the fight against COVID-19 has been the formation of herd immunity, the main tool for managing the pandemic. Study goal. The aim of the study was to assess the seroprevalence of antibodies (Abs) to SARS-CoV-2 nucleocapsid (Nc) and receptor binding domain (RBD) in the St. Petersburg population during the COVID-19 pandemic. Materials and methods. A longitudinal cohort randomized monitoring study of Ab seroprevalence (SARS-CoV-2 Nc, RBD) was organized and conducted according to a unified methodology developed by Rospotrebnadzor with the participation of the St. Petersburg Pasteur Institute. For this purpose, a cohort was formed of 1000 volunteers who participated in all five stages of seromonitoring. The cohort was divided into seven age groups: 1−17; 18−29; 30−39; 40−49; 50−59; 60−69; 70; and older (70+) years. Seropositivity levels (Nc, RBD) were assessed by quantitative and qualitative enzyme immunoassays. During the second year of monitoring, some volunteers were vaccinated with the GamCOVIDVac (84%) or EpiVacCorona (11.6%) vaccines approved in Russia. Statistical processing was carried out using Excel 2010. Confidence intervals for shares and percentages (95% CI) were calculated using the method of A. Wald and J. Wolfowitz with adjustment (A. Agresti, B.A. Coull). The statistical significance of differences was calculated by z-test, using the appropriate online calculator (p < 0.05) unless indicated. Results. There was a trend toward an increase in Nc seropositivity in stages 1−3 of seromonitoring, with a decrease in stages 4−5 among children and adults. The share of RBD seropositive steadily increased during all five stages of seromonitoring. The most frequent finding was low anti-RBD Abs levels (22.6−220 BAU/mL). High Ab levels were recorded statistically significantly less frequently. Asymptomatic forms were observed in 84−88% of SARS-CoV-2 seropositive volunteers. By the fifth stage of monitoring, this indicator significantly decreased to 69.8% (95% CI: 66.1−73.4). The monitoring revealed a statistically significant increase in anti-RBD Abs alongside a statistically significant decrease in the proportion of Nc seropositives. This dynamic was especially characteristic of persons vaccinated with GamCOVIDVac. Conclusion. Prior to the use of specific vaccines, a seroprevalence of anti-Nc Abs was noted. After the introduction of the GamCOVIDVac vaccine in adults, a decrease in the level of anti-Nc Abs was noted due to an increase in the proportion of RBD seropositive persons.

[Prevalence of viral hepatitis B markers among blood donors in the Republic of Guinea]

INTRODUCTION

The problem of transfusion safety in relation to parenteral viral hepatitis still remains relevant. Viral hepatitis B (HB) remains the most common viral infection transmitted through transfusion procedures. One of the natural phases of chronic hepatitis B (CHB) is occult hepatitis B infection (OBI), characterized by an undetectable HBsAg (regardless of the other serological markers content) in the presence of hepatitis B virus (HBV) DNA in the liver tissue and an extremely low, up to undetectable, level of viral load in the blood. In the Republic of Guinea, as in most countries on the continent, the prevention of HBV transmission through transfusion is still based on HBsAg serological testing of donors only. In this connection, OBI remains as a potential threat to blood transfusion safety. Detection of HBV DNA is a reliable preventive measure against transmission of the virus from donors with HBsAg-negative HBV infection, especially in highly endemic regions. In this regard, the study was conducted to substantiate recommendations for improving blood safety against the background of significant HBV prevalence in the Republic of Guinea.The aim of the work was the evaluation of serological and molecular markers of HBV infection in blood donors in the Republic of Guinea.

MATERIAL AND METHODS

We examined 250 blood samples obtained from donors living in Conakry, Republic of Guinea. Samples were tested for the presence of serological (surface antigen, HBsAg; antibodies (ABs) to surface (anti-HBs IgG) and core (anti-HBc IgG) antigens) and molecular (DNA) markers of HBV infection.

RESULTS AND DISCUSSION

The overall detection rate of hepatitis B markers was 83.2%; HBsAg was detected in 16.4% of all individuals. The high incidence of HBsAg in men (19.55%) compared to women (8.45%) was shown, the relative risk of HBV infection with the formation of HBsAg-positive chronic hepatitis B in males was also significantly higher. The prevalence of the HBV DNA in the study group was 30.4%, the OBI cases accounted for 15.6%. The prevalence of this form of the disease was shown in donors aged 30-49 years (24.78%), in the group of people younger than 30 years, the incidence was lower (8.73%), and at the age of over 50 years, OBI was not detected. Based on the phylogenetic analysis of 76 virus isolates, it was shown that genotype E prevails in the examined group (85.53%).Cases of pathogen DNA detection occurred in HBsAg-negative blood donors in the presence of anti-HBs IgG (n = 4), as well as in the simultaneous presence of ABs anti-HBs IgG and anti-HBc IgG (n = 7). The viral load exceeded 200 IU/ml in OBI samples. Escape mutations were detected by sequencing in each OBI sample, contributing to the virus escaping from diagnostic based on screening for HBsAg.

CONCLUSION

Assessment of the prevalence viral hepatitis B markers in blood donors, determination of genotypes and clinically significant mutations of virus variants are necessary to ensure safe medical manipulations, control and prevention of the spread of this infectious agent.

A Novel Approach for COVID-19 Patient Condition Tracking: From Instant Prediction to Regular Monitoring

Purpose: The aim of this research is to develop an accurate and interpretable aggregated score not only for hospitalization outcome prediction (death/discharge) but also for the daily assessment of the COVID-19 patient's condition. Patients and Methods: In this single-center cohort study, real-world data collected within the first two waves of the COVID-19 pandemic was used (27.04.2020-03.08.2020 and 01.11.2020-19.01.2021, respectively). The first wave data (1,349 cases) was used as a training set for the score development, while the second wave data (1,453 cases) was used as a validation set. No overlapping cases were presented in the study. For all the available patients' features, we tested their association with an outcome. Significant features were taken for further analysis, and their partial sensitivity, specificity, and promptness were estimated. Sensitivity and specificity were further combined into a feature informativeness index. The developed score was derived as a weighted sum of nine features that showed the best trade-off between informativeness and promptness. Results: Based on the training cohort (median age ± median absolute deviation 58 ± 13.3, females 55.7%), the following resulting score was derived: APTT (4 points), CRP (3 points), D-dimer (4 points), glucose (4 points), hemoglobin (3 points), lymphocytes (3 points), total protein (6 points), urea (5 points), and WBC (4 points). Internal and temporal validation based on the second wave cohort (age 60 ± 14.8, females 51.8%) showed that a sensitivity and a specificity over 90% may be achieved with an expected prediction range of more than 7 days. Moreover, we demonstrated high robustness of the score to the varying peculiarities of the pandemic. Conclusions: An extensive application of the score during the pandemic showed its potential for optimization of patient management as well as improvement of medical staff attentiveness in a high workload stress. The transparent structure of the score, as well as tractable cutoff bounds, simplified its implementation into clinical practice. High cumulative informativeness of the nine score components suggests that these are the indicators that need to be monitored regularly during the follow-up of a patient with COVID-19.

[Herd immunity to SARS-CoV-2 in the Novosibirsk Region population amid the COVID-19 pandemic]

AIM

To determine the level of SARS-CoV-2 seroprevalence among the Novosibirsk Region population against the background of the COVID-19 pandemic.

MATERIAL AND METHODS

The work was carried out in 2 phases: 1) a cross-sectional cohort study performed 28.06- 15.07.2020; 2) longitudinal cohort 3-stage seromonitoring: 1st stage 28.06-15.07.2020; 2nd 14.09-04.10.2020; 3rd 10-30.12.2020 The work was carried out according to a unified methodology developed by Rospotrebnadzor with the participation of St-Petersburg Pasteur Institute, taking into account the recommendations of the WHO. IgG antibodies to the SARS-CoV-2 nucleocapsid protein were detected by ELISA using a kit of reagents produced by the SRCMSB (Obolensk) according to the manufacturer's instructions. Statistical analysis was performed using Microsoft Excel 2010 and other programs.

RESULTS

The seroprevalence in the region's population was 9.1% (95% CI 8.0-10.2): maximum in children 14-17 years old (17.6%, 95% CI 12.3-23.9) and persons over 75 years (14.8%, 95% CI 11.4-18.8), minimum among persons 30-39 years old (4.9%, 95% CI 3.0-8.0). Increased rate was noted among the unemployed (15.4%, 95% CI 9.9-17.1) and other individuals (13.0%, 95% CI 8.6-18.5). Seroprevalence was 33.3% (95% CI 16.3-59.0) in COVID-19 convalescents and 19.0% (95% CI 13.9-25.0) in contact persons. More than 94.7% (95% CI 91.2-97.2) of seropositive individuals were asymptomatic. During the serological monitoring, seroprevalence increased from 7.4% (95% CI 6.2-8.9) at 1st stage 1 to 12.4% (95% CI 10.6-14.3) at 2nd , and 31% (95% CI 28.8-33.3) at 3rd stage.

CONCLUSION

SARS-CoV-2 herd immunity has not reached the threshold level, this does not exclude exacerbation of the epidemic process.

SARS-CoV-2 Seroprevalence Structure of the Russian Population during the COVID-19 Pandemic

The SARS-CoV-2 pandemic, which came to Russia in March 2020, is accompanied by morbidity level changes and can be tracked using serological monitoring of a representative population sample from Federal Districts (FDs) and individual regions. In a longitudinal cohort study conducted in 26 model regions of Russia, distributed across all FDs, we investigated the distribution and cumulative proportions of individuals with antibodies (Abs) to the SARS-CoV-2 nucleocapsid antigen (Ag), in the period from June to December 2020, using a three-phase monitoring process. In addition, during the formation of the cohort of volunteers, the number of seropositive convalescents, persons who had contact with patients or COVID-19 convalescents, and the prevalence of asymptomatic forms of infection among seropositive volunteers were determined. According to a uniform methodology, 3 mL of blood was taken from the examined individuals, and plasma was separated, from which the presence of Abs to nucleocapsid Ag was determined on a Thermo Scientific Multiascan FC device using the "ELISA anti-SARS-CoV-2 IgG" reagent set (prod. Scientific Center for Applied Microbiology and Biotechnology), in accordance with the developer's instructions. Volunteers (74,158) were surveyed and divided into seven age groups (1-17, 18-29, 30-39, 40-49, 59-59, 60-69, and 70+ years old), among whom 14,275 were identified as having antibodies to SARS-CoV-2. The average percent seropositive in Russia was 17.8% (IQR: 8.8-23.2). The largest proportion was found among children under 17 years old (21.6% (IQR: 13.1-31.7). In the remaining groups, seroprevalence ranged from 15.6% (IQR: 8-21.1) to 18.0% (IQR: 13.4-22.6). During monitoring, three (immune) response groups were found: (A) groups with a continuous increase in the proportion of seropositive; (B) those with a slow rate of increase in seroprevalence; and (C) those with a two-phase curve, wherein the initial increase was replaced by a decrease in the percentage of seropositive individuals. A significant correlation was revealed between the number of COVID-19 convalescents and contact persons, and between the number of contacts and healthy seropositive volunteers. Among the seropositive volunteers, more than 93.6% (IQR: 87.1-94.9) were asymptomatic. The results show that the COVID-19 pandemic is accompanied by an increase in seroprevalence, which may be important for the formation of herd immunity.

Association between Higher CD32a+CD4+ T Cell Count and Viral Load in the Peripheral Blood of HIV-infected Patients

Background:

The significance of CD32a receptor expression in individuals infected with Human Immunodeficiency Virus (HIV) is currently unclear. Previously, B. Descours et al. (2017) concluded that in patients infected with HIV-1, CD32a is expressed on resting T cells that contain HIV DNA. According to the authors, these cells are reservoirs for inducible, replication-competent viruses. However, other studies have reported that CD32a expression is associated with activated T cells and is not a marker of HIV-1 reservoirs. The aims of this study were: to determine the significance of the CD32a marker in HIV infection, to assess its expression on T helper (Th) subpopulations in peripheral blood of HIV-infected individuals and to clarify the relationship between this expression and viral load.

Methods:

For comparative analysis, the following groups were used: 27 HIV-infected patients; 11 individuals with Hepatitis C Virus (HCV) infection; 16 individuals with Hepatitis B Virus (HBV) infection; and 13 healthy donors. Peripheral blood served as the study material. The expression of CD32a receptor on Th cell subpopulations was assessed using flow cytometry. Nonparametric statistical methods were used for data analysis.

Results:

It was found that relative CD32a+ Th cell counts in HIV-infected individuals significantly exceeded corresponding values in other groups: healthy individuals (p<0.0001), those with HCV infection (p=0.0008) and those with HBV infection (p <0.0001). Among the Th subpopulations in HIV-infected patients, the CD32a receptor was predominantly expressed on Th1 cells (p<0.0001) and Th2 cells (p<0.0001), compared with Th17. We found a strong, direct correlation (r=0.78; p<0.0001) between viral load and CD32a+CD4+ T cell count in peripheral blood of HIV-infected individuals.

Conclusion:

Thus, our results provide evidence that the CD32a receptor can serve as a marker of HIV infection, and its expression depends on viral load. Clinical material was used here, for the first time, to show that CD32a is predominantly expressed on Th1 and Th2 cells.

Method for detecting hepatitis B virus in blood plasma at low viral load using real-time PCR

A method for detecting HBV DNA in peripheral blood at low viral load using real-time PCR was developed and its significance in identifying HBsAg-negative viral hepatitis B was evaluated. When developing the method, blood plasma samples and liver tissue biopsy material were used from 128 patients living in St. Petersburg, in various regions of the Russian Federation, as well as in the Central Asia countries. We also used blood plasma samples from 96 pregnant women and 37 hemodialysis center patients living in Northwestern Federal District, 199 foreign citizens undergoing medical examination to obtain work permits at the Directorate for Migration in the Northwestern Federal District, 397 conditionally healthy people living in the Socialist Republic of Vietnam. HBV was detected by nested PCR. Analytical sensitivity was tested using the stepwise dilution method. According to the method developed by us, at the first stage, the HBV DNA is amplified using at the first stage oligonucleotides flanking the genome region 2932-3182 ... 1-1846 nt., and at the second stage two oligonucleotides pairs to the genome virus regions (gene S and gene X) and corresponding oligonucleotide fluorescently labeled probes complementary to the amplified fragments regions carrying fluorophores at the 5'-end, and non-fluorescent quenchers at the 3'-end. The channel corresponding to the FAM fluorophore detects the HBV DNA S-region amplification product, and the channel corresponding to the ROX fluorophore detects the HBV DNA X-region amplification product. The method sensitivity for DNA extraction from plasma with a 100 μl volume was 10 IU/ml. Obtaining a threshold cycle Ct for only one FAM or ROX fluorophore may indicate the HBV DNA presence in a sample at a load of less than 10 IU / ml, HBV detection in this case is possible with a repeated PCR study of the corresponding sample with HBV DNA extraction from an increased plasma volume (200-1000 μl). The developed method makes it possible to identify various HBV genovariants, both characteristic and rare in the Russian Federation, circulating in other world regions. The method can be used to detect HBV in risk groups, in the population, as well as in screening blood donors in order to ensure the blood transfusions safety.

Optimization of the algorithm diagnosis chronic hepatitis B markers in patients with newly diagnosed HIV infection

The possibility of modifying the algorithms for chronic viral hepatitis B laboratory diagnosis in individuals with newly diagnosed HIV infection is analyzed. Plasma samples were used from 196 patients residing in the Northwestern Federal District. Serological HBV markers were found in 79.6% of cases. However, HBsAg was detected in 5.6% of patients. Anti-HBcore IgG antibodies are found in 62.24% of cases, anti-HBe IgG antibodies in 27.55%, anti-HBs IgG antibodies in 52.55% of cases. Using a commercial kit with a 100 IU / ml sensitivity, HBV DNA was detected in 4.6% of patients, that is, 81.8% of HBsAg-positive individuals. Using the method developed by us, HBV DNA was found in 18.36% of HIV-infected individuals, including 12.75% of cases was HBsAg-negative (latent) disease form. In the examined group, HBV of genotype D prevailed (91.7%), genotype A was detected in 8.3% of cases. The distribution of subgenotypes is presented in the following ratios: D2 - 55.6%, D1 - 22.2%, D3 - 13.9%, A2 - 8.3%. Mutations were detected in the reverse transcriptase (RT) region in 91.6% of patients, in the SHB region in 83.3%, in the Core and Precore regions in 72.2% and in 27.7% of patients, respectively. Three HBV isolates (8.3%) were identified with drug resistance mutations to lamivudine, entericavir, telbivudine and tenofovir, which are amino acid substitutions in the HBV polymerase gene at positions L180M, T184A, M204V. Vaccine escape mutations were detected in 61.1% of patients. In all samples with drug resistance mutations, escape-mutants were simultaneously present. When analyzing the basal nucleus promoter, Precore and Core regions, 22.2% of patients with the double mutation A1762T / G1764A, 25% with the mutation G1896A were identified. In one person, all three substitutions were found. In the Core region, 77.7% of patients showed mutations in one of the hot spots (codons 87, 97, 112, and 130 substitution), which can play a role in immunomodulation in CHB. Analysis of the HBV genetic structure, mutations detection early in the virus in patients with HBV can help predict the clinical course and disease progression, and ART complications. To reduce the HIV HBV co-infection burden and to appointer anti-HBV therapy, it is necessary to introduce detection the occult HBV to modify the algorithm for CHB laboratory diagnosis.

One-step quantitative RT-PCR assay with armored RNA controls for detection of SARS-CoV-2

Coronavirus disease 2019 (COVID‐19) has become pandemic since March 11, 2020. Thus, development and integration in clinics of fast and sensitive diagnostic tools are essential. The aim of the study is a development and evaluation of a one‐step quantitative reverse transcription‐polymerase chain reaction (RT‐qPCR) assay (COVID‐19 Amp) for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) detection with an armored positive control and internal controls constructed from synthetic MS2‐phage‐based RNA particles. The COVID‐19 Amp assay limit of detection was 10³ copies/ml, the analytical specificity was 100%. A total of 109 biological samples were examined using COVID‐19 Amp and World Health Organization (WHO)‐based assay. Discordance in nine samples was observed (negative by the WHO‐based assay) and discordant samples were retested as positive according to the results obtained from the Vector‐PCRrv‐2019‐nCoV‐RG assay. The developed COVID‐19 Amp assay has high sensitivity and specificity, includes virus particles‐based controls, provides the direct definition of the SARS‐CoV‐2 RdRp gene partial sequence, and is suitable for any hospital and laboratory equipped for RT‐qPCR.

One‐step RT‐qPCR assay (COVID‐19 Amp) contains an armored positive control (ARC+) and an armored internal control (ICS) constructed from synthetic MS2‐phage‐based RNA particles.

Displays high specificity and selectivity rendering it a powerful diagnostic test

Suitable for any hospital and laboratory equipped for RT‐qPCR.

Primary Immunodeficiencies in Russia: Data From the National Registry

Introduction: Primary immunodeficiencies (PID) are a group of rare genetic disorders with a multitude of clinical symptoms. Characterization of epidemiological and clinical data via national registries has proven to be a valuable tool of studying these diseases. Materials and Methods: The Russian PID registry was set up in 2017, by the National Association of Experts in PID (NAEPID). It is a secure, internet-based database that includes detailed clinical, laboratory, and therapeutic data on PID patients of all ages. Results: The registry contained information on 2,728 patients (60% males, 40% females), from all Federal Districts of the Russian Federation. 1,851/2,728 (68%) were alive, 1,426/1,851 (77%) were children and 425/1,851 (23%) were adults. PID was diagnosed before the age of 18 in 2,192 patients (88%). Antibody defects (699; 26%) and syndromic PID (591; 22%) were the most common groups of PID. The minimum overall PID prevalence in the Russian population was 1.3:100,000 people; the estimated PID birth rate is 5.7 per 100,000 live births. The number of newly diagnosed patients per year increased dramatically, reaching the maximum of 331 patients in 2018. The overall mortality rate was 9.8%. Genetic testing has been performed in 1,740 patients and genetic defects were identified in 1,344 of them (77.2%). The median diagnostic delay was 2 years; this varied from 4 months to 11 years, depending on the PID category. The shortest time to diagnosis was noted in the combined PIDs-in WAS, DGS, and CGD. The longest delay was observed in AT, NBS, and in the most prevalent adult PID: HAE and CVID. Of the patients, 1,622 had symptomatic treatment information: 843 (52%) received IG treatment, mainly IVIG (96%), and 414 (25%) patients were treated with biological drugs. HSCT has been performed in 342/2,728 (16%) patients, of whom 67% are currently alive, 17% deceased, and 16% lost to follow-up. Three patients underwent gene therapy for WAS; all are currently alive. Conclusions: Here, we describe our first analysis of the epidemiological features of PID in Russia, allowing us to highlight the main challenges around PID diagnosis and treatment.

[Identification and molecular-genetic characteristics of the hepatitis B virus among HIV-infected patients in Arkhangelsk.]

AIM

To estimate the prevalence and characterize the hepatitis B virus among HIV-infected patients with virological failure of antiretroviral therapy in Arkhangelsk.

MATERIAL AND METHODS

HBV markers determinations (HBsAg, anti-HBs IgG, antiHBcor IgG, DNA HBV) were performed in isolates from blood plasma samples 64 HIV-infected patients with virological failure of antiretroviral therapy (viral load >50 IU / ml after 6 months of antiretroviral therapy or an increase in viral load after primary suppression of viral replication). For the detection of the hepatitis B virus, nucleic acids were isolated using the commercial kit «AmplePrime Ribo-prep». The virus presence analysis was performing by the polymerase chain reaction (PCR) method with hybridization-fluorescence detection in "real time" using the commercial set of «AmpliSens^® HBV-FL». In the future, we used the method developed by the Saint-Petersburg Pasteur Institute, which allows detecting HBV in biological material with a low viral load.

RESULTS

HBsAg-negative (occult) HBV was detect in 28 (43.8%) HIVinfected patients. Only HBV genotype D was detected, and the HBV subgenotype D1 prevailed (39.3%) compared with the HBV subgenotype D2 (32.1%) and D3 (28.6%). Serological markers in 42.8% of patients with HBV DNA were founding. Two HBV isolates with drug resistance mutations in the polymerase gene, leaded to amino acid substitutions (L180M, M204V) associated with the resistance development to lamivudine, entecavir, telbivudine and tenofovir were identifying.

CONCLUSION

The occult (HBsAg-negative) HBV high prevalence among HIV-infected patients suggests the need to use molecular-biological diagnostic methods to identify HBV, as well as to analyze the HBV drug resistance mutation before starting antiretroviral therapy for HIV.

[The prevalence clinically significant virus mutations among patients with chronic viral hepatitis B.]

The prevalence of clinically significant virus mutations in patients with chronic viral hepatitis B from the Kyrgyz Republic was analyzed. Blood plasma samples of 64 patients with verified chronic viral hepatitis B obtained from Kyrgyzstan indigenous people were used in the work. Asymmetric PCR was carried out with extended oligonucleotides and the first reaction amplification product was further used in a new PCR with one of the nested pairs overlapping primers that flanked the entire HBV genome together, followed by sequencing. Based on the phylogenetic analysis of 64 HBV isolates obtained from patients from the Kyrgyz Republic, it was shown that only the genotype D virus was present in the examined group, the HBV subgenotype D1 (68.75%) prevailed compared with the HBV subgenotype D2 (18.75%) and subgenotype D3 (12.5%). For all subgenotypes, several independent infection sources are obvious, subclusters that include isolates from Kyrgyzstan, Kazakhstan and Uzbekistan are distinguished, as well as subclusters that include isolates only from Kyrgyzstan, which are less similar to isolates previously deposited in the international database, which probably indicates an independent HBV homologous evolution in the region. Clinically significant mutations were identified in 26.5% of patients. Including 12.5% with escape mutations that prevent the virus detection and / or allow the virus to replicate despite the vaccine (122K, 128V, 133I, 134N). Another 12.5% of the isolates are characterized by mutations that are independently associated with the liver cirrhosis and hepatocellular carcinoma development, including 21, 24, 27 nucleotides deletions in the Pre-S2 region and the S11F mutation in the PreCore region. In one case, unusual 236S and 250P mutations were found in the positions described as drug resistance sites of the P region associated with the resistance development to adefovir, tenofovir, and entecavir. The hepatitis B virus genetic structure analysis, early virus mutations detection in patients with chronic hepatitis B virus can help to choose the right vaccination strategy, antiviral and immunosuppressive therapy, as well as predict the clinical course and disease progression.

Some opportunities for immunotherapy in coronavirus infection

Here we review means of immunomodulatory therapy for coronavirus infection caused by SARS-CoV-2 (COVID-19). It has been appreciated that highly limited arsenal of relatively effective means and methods of prevention and treatment of the COVID-19 pandemic is available. The goal of our study was to analyze some therapeutic approaches based on available publications for COVID-19 treatment viewed from acting via innate immunity system. Convalescent plasma serotherapy represents one of the means with verified therapeutic efficacy that was accompanied with decreased viral load and relief of the disease symptoms. The drawback of serotherapy results from limited number of potential plasma donors and profound variety in amount of SARS-CoV-2-specific antibodies found in donor plasma. Another approach to COVID-19 therapy is based on using monoclonal antibodies engineered to target specific virus antigenic determinants, most often surface spike antigen. Antibodies blocking such antigen are able to prevent virus entrance into target cells and development of overt infection. On the other hand, there are monoclonal antibodies abrogating production or binding of excessive amounts of pro-inflammatory cytokines, such as IL-6, TNFα, etc., some of which (tocilizumab) have been already tested in COVID-19 therapy, whereas the remaining preparations are being currently investigated and tested. A certain breakthrough in COVID-19 therapy was provided by the well-known drugs chloroquine and dihydrochloroquine, which have proven to be effective as antiviral, anti-inflammatory and immunomodulatory means. Finally, a new multicomponent immunomodulatory preparation Cytovir-3 has been proposed already passed clinical trials and recommended for use in prevention and treatment of influenza and SARS and might have found its own niche in preventing COVID-19, as SARS-CoV-2 also belongs to the group of acute respiratory viruses. Thus, the arsenal of means for COVID-19 prevention and treatment contains the drugs for immunomodulatory therapy and prevention of immune-related disorders developing in response to invasion pathogenic viruses and lowering a risk of possible damage. Hence, correct and scientifically justified use of such remedies will increase overall effectiveness of fight against the coronavirus pandemic.

[Hepatitis B virus identification in a blood plasma at a low viral load.]

To analyze the method for detecting HBV DNA in peripheral blood at low viral load and evaluate its significance in identifying HBsAg-negative viral hepatitis B. In this work, samples of blood and liver tissue biopsy material were used from 128 patients living in the Russian Federation and the Republic of Uzbekistan without CHB and with CHB confirmed detection of circle covalently closed HBV DNA in hepatocytes. Plasma viral load was measured using the «AmpliSens® HBV-Monitor-FL» kit. HBV at low viral load was detected by nested PCR. Analytical sensitivity was checked by step dilution. According to our method, at the first stage, an asymmetric PCR is carried out using extended oligonucleotide primers with different melting points, complementary to the hepatitis B different genotypes genomes greatest similarity region. To increase the sensitivity, a second PCR is performed using the first reaction amplification product and internal primers. The sensitivity of the method for DNA extraction from 100 μl of plasma was 5 IU / ml, specificity 100%. Since, in spite of the HBV genotypes characteristic geographical distribution, the detection of "alien" genovariants for certain territories is becoming more frequent, we tested the method in geographically remote but active international relations with the Russian Federation regions with a high frequency of hepatotropic viruses. The developed method for detecting HBV DNA in blood plasma at low viral load based on PCR technology allows the various HBV gene variants identification and genotyping, both characteristic and rare in the Russian Federation, circulating in other world regions. The method can be used to detect HBV in risk groups, in a population, as well as when screening blood donors in order to ensure the blood transfusions safety.

[The quantitative determination method of covalently closed circular DNA HBV in puncture biopsy specimens of the liver.]

To analyze the method HBV covalent-closed circular DNA quantitative determination in liver puncture biopsies and evaluate its significance in identifying HBsAg-negative viral hepatitis B. In this work, samples of liver tissue biopsy material were used from 128 patients living in St. Petersburg, in various regions of the Russian Federation, as well as in the Republic of Uzbekistan. For quantitative analysis of HBV covalently closed circular DNA in a biopsy material a method was developed based on real-time PCR using TaqMan probes for the target fragment and for the endogenous reference gene, based on the detecting ccc HBV DNA method of Pollicino T. et al. When quantifying ccc DNA HBV in liver tissue of 18 moderately HBV activity with HBV DNA PCR positive results patients and 16 inactive HBsAg carriers, the ccc DNA HBV content was significantly different between groups (p<0.034) and in terms 1 copy of the β-globin gene among moderate activity HBV patients amounted to 1.71±1.32 copies/cell, and for inactive HBsAg carriers 0.15±0.14 copies/cell. In the group of patients with severe liver fibrosis and cirrhosis, the amount of ccc DNA HBV in liver tissue in patients with HBV averaged 2.5±0.4 copies/cell, in patients with HBV + D on average 0.7±0.25 copies/cell, in patients with HCV + HBV co-infection 0.45±0.07 copies/cell, in patients with a preliminary diagnosis of chronic hepatitis C hepatitis, on average 0.12±0.04 copies/cell, in patients with cryptogenic hepatitis 0.2± 0.05 copies/cell. A significant difference was shown between the group of patients with chronic hepatitis B with marked fibrosis and cirrhosis of the liver with other patients groups, except for the group of 18 moderate activity chronic hepatitis B patients. The values of Student's t-test when compared with other groups were respectively: for patients with a HCV preliminary diagnosis t=5,92 p<0,05 f = 19, patients with cryptogenic hepatitis t=5,71 p<0,05 f = 18, with «inactive HBsAg carriage» t=5,55 p<0,05 f = 29, with HCV + HBV co-infection t=5,05 p<0,05 f = 15 and HBV + D co-infection t=3,82 p<0,05 f = 17. The covalently closed circular DNA HBV quantitative assessment method in liver puncture biopsies allows identifying HBsAgnegative chronic viral hepatitis B forms and also reflects the virus replication activity, which, in turn, makes it possible to assume further disease progression and evaluate the antiviral therapy effectiveness.

JUBILEE 2018: 110th ANNIVERSARY OF THE FOUNDATION OF THE ST. PETERSBURG PASTEUR RESEARCH INSTITUTE OF EPIDEMIOLOGY AND MICROBIOLOGY AND THE 95th ANNIVERSARY OF THE NAMING OF THE INSTITUTE AFTER PASTEUR

Abstract. The article presents not previously published archive data and copies of documents about Lieberman Yakov Yulievich, the first director of the Petrograd Bacteriological Institute named after Pasteur (now called Saint Petersburg Pasteur Institute). Based on the personal testimony of Ya.Yu. Lieberman, Pyotr Petrovich Maslakovets and Georgii Dmitrievich Belonovsky (the founders and leaders of the Institute) preserved in the archive funds of the Directorate of the Federal Security Service (FSB) of Russian Federation for St. Petersburg and the Leningrad Region, and taking into account the Act of the Commission for the Institute Inspection from December 1930, provided in the article, the authors consistently trace the path of transformations that the Institute has undergone since its foundation. These data are illustrated by copies of publication advertisements contained in the annual city reference book "All Petersburg" for years 1910, 1911, 1912, 1914, 1923, 1924, and 1925 (from the funds of the National Library of Russia). The article also contains copies of official documents dated 1913 and 1914 and stored in the funds of the Central State Historical Archive of St. Petersburg. All documents provided establish the fact that the date of creation of the Institute is 1908.

[THE IDENTIFICATION OF STENOTPHOMONAS MALTOPHILIA USING THE TECHNIQUES OF DIRECT SEQUENATION 16S P RNA AND MALDI-TOF MASS-SPECTROMETRY]

The in-hospital infections are one of the most serious problems of medicine, especially if patients have a background immunosuppression of various genesis conditioned by both disease itself and corresponding therapy. The detection of presence of infection and identification of agent and detection of its resistance are needed for choosing adequate therapy. At that, high heterogeneity of strains and multiple resistance of nosocomial infections to antibiotics and antimicrobial pharmaceuticals and standardization of antibacterial prevention and number of other causes becomes an obstacle for both determination of medicinal sensitivity of bacterium and for identification of pathogen itself in patient. One of the most complicated in antibacterial therapy pathogens causing pyo-septic diseases, are bacteria Stenotrophomonas spp., the only significant species out of them - Stenotrophomonas maltophilia has primary multiple antibiotic resistance. The significance of early identification of S.maltophilia is obvious. The application of MALDI-ToF mass-spectrometry requires shortage of of time of species identification of primary bacterial culture up to 1-2 hours including sampling preparation and analysis of obtained specters. The sequencing of 16S rRNA requires shortage of of total time od species identification of pathogen from clinical sample (blood) up to 1-12 hours, including sampling preparation ans comparison with successions presented in international data base. The given technique permits to exclude out of analysis prolonged period of obtaining a pure hemoculture of agent. The application of sequencing of 16S rRNA and MALDI-ToF mass-spectrometry as an alternative high-precision techniques shorten time of identification of bacteria, including detection of agent directly in blood of patient. Hence, occurs optimization of complex treatment and shortage of time of selection of adequate therapy that is especially important in case of oncological patients because sensitivity of cultural methods can be diminished due to preventive antibiotics' therapy.

Immunogenicity of Human Interferon-Beta-Containing Pharmaceuticals

Multiple sclerosis is a severe autoimmune disease with inflammatory component that continues to be resistant to treatment. One of the approaches retarding its progression is based on using nonspecific therapy with human interferon-beta (IFN-β)-containing pharmaceuticals. Neutralizing antibodies (NAbs) against genetically engineered pharmaceuticals developed by the patient's immune system, which reduce their therapeutic and biological activity, pose a serious problem. Cell lines sensitive to IFN-β activity also quantifying NAb level are applied because direct measurement of IFN-β antiviral activity is complicated. This study was aimed at standardization and validation of a reporter cell system for measuring anti-human IFN-β NAb titers, and evaluation data were obtained with samples from 33 patients with multiple sclerosis.

[The comparative analysis of immunologic techniques of detection of anti-phospholipid antibodies]

The laboratory diagnostic of anti-phospholipid syndrome consists in detection of anti-phospholipid antibodies using technique of enzyme-linked immunosorbent assay namely in detection of anti-cardiolipin antibodies and antibodies to β2-glycoprotein. In spite of the fact that serological diagnostic plays a key role in diagnosing anti-phospholipid syndrome application of laboratory tests s complicated by their insufficient standardization. The new approach to detection of anti-phospholipid antibodies became application of immune blotting on the basis of polyvinylidenfluoride membrane. As compared with enzyme-linked immunosorbent assay, the advantage of the mentioned technique is in using hydrophobic solid phase for sorption of antigens. The porous structure of polyvinylidenfluoride membrane orientates hydrophilic areas of phospholipids and by that ensures their more dense distribution imitating bi-lipid layer of membranes of living organism. To specify and compare value of different techniques the comparison was implemented concerning the results of measurement of anti-phospholipid antibodies in enzyme-linked immunosorbent assay test-systems of various manufacturers and reagents kits for immune blotting. The collection was assembled including bio-materials from 47 patients with non-cardioembolic ischemic strokes, 20 patients with recurrent thrombosis of deep veins of lower extremities and 50 patients with obstetrics pathology and also 30 healthy donors. In the given serums aKlaIgG, aKlaIgM, aβ2glycoprotein I were measured using enzyme-linked immunosorbent assay technique assisted by test-systems of Euroimmun and Orgentes Diagnostica and the samples with the highest titre using immune blotting technique with reagents manufactured by Medipan. On the basis of measurement of anti-phospholipid antibodies by various enzyme-linked immunosorbent assay test-systems the rate of aβ2glycoprotein I amounted to 31% in case of Euroimmun reagents kits for enzyme-linked immunosorbent assay, 78% in case of Orgentec Diagnistica test-systems for enzyme-linked immunosorbent assay, aKlaIgG - 2% and 30%, aKlaIgM - 31% and 54% correspondingly. The measurement of anti-phospholipid antibodies using immune blotting technique on Medipan test-systems in bio-samples with the highest titres detected aβ2glycoprotein I in all patients, aKlaIgG in 70% and aKlaIgM in 30% of patients. The convergence between three commercial reagents kits varies from 20% to 88%. The standardization of commercial test-systems still to be achieved. The new technique of immune blotting can be appliedjointly with classic techniques ofserological diagnostic of anti-phospholipid syndrome. The absence of algorithms of diagnostic and standardization of different test-systems for detection of anti-phospholipid antibodies prejudices reliability of serological diagnosis of anti-phospholipid syndrome and therefore existence of anti-phospholipid syndrome as a nosologic unit.

[The methods of detection of binding and neutralizing antibodies to preparations of interferon-beta]

The human recombinant β-interferon is most frequently applied for treatment of remittent recurrent form of multiple sclerosis using pharmaceuticals. The clinical response to applied therapy is absent in some of patients that can be conditioned by development of antibodies too preparations. Depending on possibility of blocking binding of human recombinant β-interferon with its receptor, all antibodies are divided on binding and neutralizing ones. The purpose of study is to investigate analytical and clinical diagnostic parameters of tests using for detection of different types of antibodies synthesized against human recombinant β-interferon. The study sampling consisted of 33 patients with remittent recurrent form of multiple sclerosis receiving therapy with human recombinant β-interferon and also of 40 donors and 15 patients with multiple sclerosis without therapy with human recombinant β-interferon. The concentration of binding antibodies was measured by enzyme-linked immunosorbent assay. Also immune blotting assay was applied. The titer of neutralizing antibodies was determined using cell line HL-116 sensitive to human recombinant β-interferon. The binding and neutralizing antibodies were not detected in donors and patients without human recombinant β-interferon therapy. The prevalence of binding antibodies to human recombinant β-interferon amounted to 57.6% when analysis of samples using immune blotting assay was used and 60.6% when commercial testing system was applied. The statistical analysis of results demonstrated high convergence and correlation of values of concentrations of binding antibodies obtained using immune blotting assay and enzyme-linked immunosorbent assay (r=0.9159, p<0.0001). The clinically significant titers of neutralizing antibodies were detected in 21.21°% of patients. All patients with clinically significant titer of neutralizing antibodies were positive in relation to binding antibodies measured by immune blotting assay and enzyme-linked immunosorbent assay. The high correlation between values of titers of neutralizing antibodies and concentration of binding antibodies measured by immune blotting assay (r=0.7909, p=0.0055). The application in clinical practice of data concerning presence of binding and neutralizing antibodies to human recombinant β-interferon can input into optimization of therapy with expensive biologic preparations in patients with multiple sclerosis and other autoimmune diseases.

[The detection of level of free light chains of immunoglobulins using enzyme-linked immunosorbent assay techniques for diagnostic of monoclonal gammopathy.]

The content of free light chains of immunoglobulins kappa and lambda and also ratio of their concentrations in blood serum are important diagnostic and prognostic markers in case of monoclonal gammopathy. The technique FreelightTM based on nephelometric detection of free light chains using polyclonal antibodies is one of common modes of detection of free light chains. The actual study was carried out with purpose of validating of national test-system for detection of level of free light chains in blood serum using technique of enzyme-linked immunosorbent assay. The samples of blood serum were taken from 89 healthy donors and 165 patients with monoclonal gammopathy. To detect the level of free light chains enzyme-linked immunosorbent assay testsystem "Polygnost" was used based on application of monoclonal a ntibodies. The number of analytical characteristics of reagents set was determined including limit of detection and range of linearity. The limit of detection of free light chains using enzymelinked immunosorbent assay test-system was two times lower than claimed by manufacturer of nephelometric set "FreelightTM". Hence, analytical characteristics of enzyme-linked immunosorbent assay set make it possible to detect the level of free light chains within range of standard values. The reference limits were established concerning concentration of free light chains kappa (3.25-15.81 mkg/ml), free light chains lambda (3.23-28.05 mkg/ml) and their ratio (0.3-1.9) in blood serum that factually matched the recommended intervals for "FreelightTM" set. In patients with monoclonal gammopathy the level of free light chains was reliably higher (p<0.01) as compared with control group of healthy donors. In case of paraproteinemia reliable alteration (p<0.01) of ratio free light chains kappa/free light chains lambda was observed in comparison with control group. The results of actual study testify that national enzyme-linked immunosorbent assay set has good analytical and diagnostic characteristics and it can be used in laboratory practice.

[Past and present of streptococcus pyogenes: some pathogenic factors and their genetic determination]

In this review two aspects dealt with Streptococcus pyogenes--one of the leading agent responsible for infectious diseases and another related to their complications in humans worldwide--are given. In the first part of the review the comparative evaluation of laboratory diagnostic approaches and methods used in the second half of the twentieth century and molecular technologies developed during last twenty years are described. In the second part the role of the main microbial pathogenic factors as well as the data on intra- and interspecies genetic exchange with extrachromosomal genetic elements and their influence on biological properties of the pathogen are discussed. Essential for today possibilities for molecular epidemiology of streptococcal pathology approaches must be introduces in diagnostic laboratories within the country.

[Content of some pro- and anti-inflammatory cytokines in blood sera of leptospirosis patients]

AIM

Study the content of some pro- and anti-inflammatory cytokines in blood sera of leptospirosis patients in dynamics of infectious process and the role of these cytokines in the disease immunopathogenesis.

MATERIALS AND METHODS

The content of cytokines in blood sera was determined by a method based on xMAP technology with a standard panel consisting of 9 analytes: TNF-α, MCP-1, IL-8, IL-4, IL-6, IL-10, IL-1Ra, IL-12 (p70), IFN-γ.

RESULTS

A significantly increased level of IL-8, IL-10, TNF-α was confirmed and the increased content of MCP-1 in leptospirosis patients compared with practically healthy donors was established for the first time. Correlations between cytokines during leptospirosis were detected.

CONCLUSION

The data obtained show that cytokines play an important role in leptospirosis immunopathogenesis.

[Fc-receptor proteins of Streptococcus pyogenes and pathogenesis of post-infection complications]

Phenomenon and mechanism of non-immune binding of immunoglobulins G and A by various emm-genotypes of group A streptococcus and in particular M-family proteins--main factors of pathogenicity of this causative agent of widespread human diseases are examined. The role of these receptor proteins in pathogenesis of post-streptococcal damage of kidneys (glomerules) and heart (myocarditis) are proved. Results of long-term studies that confirm hypothesis of initiating function of Fc-receptor M proteins in genesis of immune inflammation in organ tissues that precede development of glomerulonephritis and myocarditis are provided. According to the basic position, Fc-binding of an immunoglobulin by M proteins initiates production of anti-IgG, immune complexes of various composition and complement activation, deposition of those in tissues results in lymphocyte infiltration and production of pro-inflammatory cytokines. Literature data on the role of Fc-binding proteins in genesis of IgA-nephropathies and rheumatoid factor is also examined. An important role of other factors of the microbe is discussed such as cross-reacting antigens, erythrogenic toxin B, system of streptokinase-plasmin receptor or endostreptosin in post-streptococcal processes in kidneys. Their participation in the process must be mediated by an inflammation reaction in the tissue that is initiated by interaction of immunoglobulins with Fc-binding proteins of the microbe. A novel approach to understanding the nature of this pathology allowed to establish the ability of Fc-fragments of immunoglobulin G to suppress the development of the process.

[Quantitative determination of HBsAg in blood sera and hepatitis B virus covalently closed circular DNA in liver tissue as markers of chronic viral hepatitis B activity]

AIM

Quantitative evaluation of HBV covalently closed circular DNA (cccDNA) content in liver tissue of patients with moderately active CHBV course compared with inactive HBsAg carriers as well as establishment of a possible link between HBV cccDNA in liver cells and HBsAg level in blood sera in these groups of patients.

MATERIALS AND METHODS

Patients (n = 34) with CHBV diagnosis were examined for levels ofALT, HBsAg (qualitatively and quantitatively), anti-HBcor IgG, anti-HBe IgG, anti-HCV IgG+IgM, anti-HDV IgG+IgM, HBV DNA in qualitative and quantitative variant. Liver biopsy was carried out in all the patients. HBV DNA was determined in liver tissue by Pollicino T. et al. (2004).

RESULTS

Based on HBV DNA PCR, the patients were allocated to a group of inactive HBsAg carriers (n = 16) and CHBV (n = 18) of moderate activity. Viral load in CHBV patients had a mean of 540 +/- 230 IU/ml. ALT level in carriers was comparatively lower than in patients with CHBV. HBsAg level in blood of inactive carriers was significantly lower, 940 +/- 259 IU/ml against 2559 +/- 982 IU/ml in patients with CHBV (p < 0.05). The quantity of cccDNA per 1 cell in inactive HBsAg carriers--0.15 +/- 0.14, and in patients group of CHBV with moderate activity--1.71 +/- 1.32 (p = 0.034).

CONCLUSION

The method of quantitative determination of HBV cccDNA in liver tissue of patients was worked out. Differences in quantitative content of HBsAg in blood sera of inactive carriers and CHBV patients with moderate activity reflect changes in the extent of hepatocyte infection by HBV.

[Features of population composition of peripheral blood CXCR3-positive lymphocytes in chronic viral hepatitis c patients]

AIM

Quantitative determination ofCXCR3+, CCR5+ and CCR6+ cells in major lymphocyte populations: T-helpers (Th), cytotoxic T-lymphocytes (CTL), natural killers (NK) and T-natural killer cells (TNK), B-lymphocytes in patients with chronic viral hepatitis C (CVHC).

MATERIALS AND METHODS

Content of lymphocyte populations carrying chemokine receptor CXCR3 was studied, chemokine receptors CCR5 and CCR6 were evaluated on T-lymphocytes, in peripheral blood of 19 CVHC patients and 32 conditionally healthy donors. Cell populations were determined by flow cytofluorometry by using various combinations of monoclonal antibodies: for evaluation of Th and CTL (CD3/CD4/CD8/CXCR3/CCR5/CCR6); NK and TNK (CDl6/CD56/CD3/ CXCR3); B-cells (CD 19/CD45/CXCR3).

RESULTS

In patients with CVHV compared with healthy donors a significant increase of quantity of CXCR3-positive Th was detected, however the content of CXCR3-positive CTL did not differ in the groups compared; CXCR3+ NK cell content was lower with equal content of CXCR3+ TNK. Analysis of quantity of CXCR3+ B-cells showed an increase of more than 3.5 times in CVHC patients. Significant differences in relative content of Th and CTL carrying CCR5 and CCR6 were not detected despite a non-significant increase of quantity of CCR5+ and CCR6+ Th.

CONCLUSION

Content of major lymphocyte populations carrying chemokine receptor CXCR3 changed significantly compared with conditionally healthy donors in peripheral blood of CVHC patients. The increase of quantity of CXCR3-positive B-cells may be associated with infection of these cells by HCV or development of extra-liver manifestations of HVHC.

Common intronic D variant of ACE gene is associated with endothelial dysfunction in COPD

BACKGROUND

Pathogenesis of chronic obstructive lung disease (COPD) includes primary inflammatory events, multiple vascular reactions, remodeling of bronchial and vascular walls.

OBJECTIVE

The aim of present single-center study was to assess relations between angiotensin-converting enzyme (ACE) gene and prevalence of clinical symptoms characteristic to COPD.

METHODS

The study involved sixty-three male patients with COPD (44-86 years old, a mean of 60.4 years). COPD diagnostics was performed according to common criteria, including evaluation of systolic pressure in pulmonary artery (SPPA) and endothelial disfunction (ED). Genotyping of ACE I/D was performed by means of gene-specific PCR.

RESULTS

1. Allele distribution of studied gene alleles among COPD patients did not differ from control age-matched group. 2. Detectable endothelial dysfunction in COPD patients was shown to correlate with high-producer D allele of ACE gene, at an odds ratio of 6.632 (CI = 1.67-26.31; chi2 = 8.39, p = 0.004). Moreover, detectable ED correlated with numbers of COPD exacerbations per year.

CONCLUSIONS

These findings suggest possible association of the functional ACE D allele with altered vascular responses that may modulate development of distinct COPD symptoms. The results are obtained in a limited clinical cohort, and deserve repeated trials in other groups of COPD patients.

[The clinical immunologic characteristics of different variants of course of ulcer colitis]

The study was carried out to determine clinical and immunologic predictors of unfavorable variant of course of ulcer colitis. The sample included 89 patients (48 females--53.9% and 41 males--46.1%) with ulcer colitis established on the basis of clinical, endoscopic and morphologic data. The age of patients was 18-79 years and mean age--42.49 +/- 1.61 years. The patients were divided on two groups depending on clinical course of disease: group 1 with favorable course and group 2 with unfavorable course. The group 2 included patients with frequently relapsing form of disease, patients with hormone-depended/hormone-resistant form of disease and patients with severe exacerbation ua ulcer colitis at the moment of examination. The groups were compared by gender and age. All patients underwent medical history and complaints acquisition and total clinical examination. The clinical and biochemical analysis of blood was made too. The severity of disease was established using the calculation of Trulove- Witts indicator The anti-neutrophil cytoplasmic antibodies of classes IgG and IgA were analyzed using indirect immunofluorescence (Euroimmun AG, Germany). The diagnostic anti-neutrophil cytoplasmic antibodies titer was established in 58 out of 87 of examined patients (66.6%). The antineutrophil cytoplasmic antibodies of class IgG was revealed in 42 patients and anti-neutrophil cytoplasmic antibodies of class IgA in 27 patients. The combination of both classes of anti-neutrophil cytoplasmic antibodies was established in 11 examined patients. In the group of favorable course of disease the diagnostic titer of anti-neutrophil cytoplasmic antibodies was revealed in 20 patients (51%). At the same time, in the subgroups with frequently relapsing, hormone-depended/hormone-resistant and severe forms of disease these antibodies were revealed with rate of 76, 77 and 86.3% correspondingly. Hence, the anti-neutrophil cytoplasmic antibodies can be used both in diagnostic of ulcer colitis and in prognosis of course of disease.

[The diagnostic role of chemokines and their receptors in chronic hepatitis C]

The chronic hepatitis C is characterized by the increase of inflammatory disorders and progression of fibrosis of liver The corresponding immunologic mechanisms of hepatic lesions are still undiscovered. The actual review presents the analysis of scientific publications and genuine research data concerning the role of chemokines in pathogenesis of chronic hepatitis C. The chemokines are small cationic proteins enhancing transit and precipitation of migrating cells (leucocytes mainly) in tissues and organs. The significant role of chemokines in tissue homeostasis, in case of inflammation, wound healing and cell proliferation is demonstrated. The particular kinds of chemokines are produced by different types of cells and impact target cells through their specific receptors. According the data of various studies, chemokines and chemokine receptors of CC-families and CXC-families are involved in fibrosing processes and anti-inflammatory activation of hepatic-biliary system under chronic hepatitis C. The diversity of producers and targets of chemokines in liver is very pronounced: hepatocytes, stellar cells, endothelium cells, macrophages (Kupffer cells), dendritic cells, lymphocytes and monocytes. The review considers pathogenesis of chronic hepatitis C from the standpoint of participation of chemokines and chemokine receptors at different stages of cellular transit. The most important cellpopulations involved into pathologic changes under chronic hepatitis C are characterized. The decrease of expression of such gens as CCR1, CCR2, CCR3, and CCR5 in blood leucocytes deserves additional studies to establish their diagnostic values as a marker of disorders of immune system in patients with chronic hepatitis C.

[The value of quantitative analysis of procalcitonine in diagnostics of septic complications in patients with autoimmune rheumatic diseases]

The infections very often complicate the course of autoimmune rheumatic diseases. In diagnostic of septic complications in rheumatic patients the new biomarkers of infections can have a decisive importance. The procalciotonine test is one of them. The issue was to evaluate the diagnostic informativity of this test. The sample included 93 patients. The examination was applied to 65 patients with rheumatic diseases. Among them, 13 patients had bacterial infections. The group consisted of 33 patients with rheumatoid arthritis, 11 patients with systemic lupus erythematous, 6 patients with systemic angiitis, and 15 patients with other rheumatic diseases. The comparative group included 27 patients of cardio-therapeutic profile and 8 of these patients had bacterial infections. The procalcitonine test was applied with quantitative electrochemiluminescent technique. In patients with rheumatoid arthritis the mean levels of procalciotonine test consisted 0.10 +/- 0.13 ng/ml; with systemic lupus erythematous--0.08 +/- 0.06 ng/ml; with systemic angiitis--0.22 +/- 0.2 ng/ml; with other rheumatic diseases--0.12 +/- 0.15 ng/ml; of cardio-therapeutic profile without infections--0.08 +/- 0.06 ng/vl/ With threshold of procalcitonine test higher than 0.5/ml the sensitivity to diagnostic of infections consisted of 58%, specificity--94% in the group with rheumatic diseases. The procalciotonine test in case of no infection process with values higher than 0.5 ng/ml was detected in three patients. The evaluation of dependence of sensitivity and specificity for procalciotonine test and C-reactive protein the area under curve of procalcitonine test was larger in patients with rheumatic diseases (0.85 against 0.79) and in patients of cardio-therapeutic profile (0.92 against 0.90). The quantitative procalcitonine test is the best technique to detect septic complications in rheumatic patients.