[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.

Modified quantitative approach for assessing peripheral blood TREC and KREC levels in immunodeficient patients

Introduction. The immune status is a multifaceted parameter quantitatively and qualitatively analyzing functional activity immune system state in immune organs as well as some non-specific mechanisms of antimicrobial protection. Peripheral blood level of T-receptor excision rings (TREC) and B-cell excision rings (KREC), respectively, can serve as surrogate markers of T- and B-cell maturation. Currently, the diagnostic kits available on the market have two significant disadvantages: i) the kits are aimed at diagnosing immunodeficiency conditions only in newborns and children, while keeping adult patients uncovered; ii) essentially, use solely single reference normalization gene for data normalization resulting in increased variability and decreased sensitivity of the assay data. The aim: to develop a highly sensitive method for laboratory assessment of the state of immunity in immunodeficient patients by using real-time PCR for assessing TREC and KREC level in children and adults. Materials and methods. There were used whole blood and dry blood spot samples obtained from newborns and adults, apparently healthy individuals as well as patients with verified PID and HIV-infection. A total of 2577 samples were examined. Commercial kits were used as comparison methods. Results. Multiplex PCR was carried out, analyzing the number of target molecules TREC and KREC, as well as fragments of the HPRT and RPP30 normalization genes analyzed with the developed series of plasmid calibrators. The established analytical range of TREC/KREC DNA measurements comprised 103 to 109 copies/mL. The accuracy of measurements on a tablet-type instrument (CFX) was 95.84%, on a rotary-type instrument (Rotor-Gene 3000) 95.11%, which corresponds to the standard indicator. The equivalence between the data obtained after assessing whole blood samples and dry blood drops was shown. The data analysis allowed to find out 100%-diagnostic specificity and sensitivity of the method proposed. Conclusion. The method developed by us allows to diagnose decline in T- and/or B-cell immunity in children and adults and can be used to detect TREC and KREC molecules both in peripheral whole blood samples and dry blood spots using Guthrie cards. Moreover, the uniform values of reference norms can be used regardless of the type of analyzed clinical material. The study data evidence about potential for effective use of multiplex PCR diagnostics both for complex primary testing/screening of newborns and assessing state of immunity to identify adult patients with PID and as a part of the diagnostic monitoring of patients with secondary immunodeficiencies, e.g., HIV infection.

Predictive value of specific cytokines for lethal COVID-19 outcome

In our study, we aimed to evaluate the significance of specific cytokines in blood plasma as predictive markers of COVID-associated mortality. Materials and methods. In plasma samples of 29 patients with PCR-confirmed COVID-19 we measured the concentrations of 47 molecules. These molecules included: interleukins and selected pro-inflammatory cytokines (IL-1, IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-9, IL-12 (p40), IL-12 (p70), IL 13, IL-15, IL-17A/CTLA8, IL-17-E/IL-25, IL-17F, IL-18, IL-22, IL-27, IFN2, IFN, TNF, TNF/Lymphotoxin-(LTA)); chemokines (CCL2/MCP-1, CCL3/MIP-1, CCL4/MIP-1, CCL7/MCP-3, CCL11/Eotaxin, CCL22/MDC, CXCL1/GRO, CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10, CX3CL1/Fractalkine); anti-inflammatory cytokines (IL-1Ra, IL-10); growth factors (EGF, FGF-2/FGF-basic, Flt-3 Ligand, G-CSF, M-CSF, GM-CSF, PDGF-AA, PDGFAB/BB, TGF, VEGF-A); and sCD40L. We used multiplex analysis based on xMAP technology (Luminex, USA) using Luminex MagPix. As controls, we used plasma samples of 20 healthy individuals. Based on the results, we applied Receiver Operating Characteristic (ROC) analysis and Area Under Curve (AUC) values to compare two different predictive tests and to choose the optimal division point for disease outcome (survivors/non-survivors). To find optimal biomarker combinations, we as used cytokines concentrations as dependent variables to grow a regression tree using JMP 16 Software.Results. Out of 47 studied cytokines/chemokines/growth factors, we picked four pro-inflammatory cytokines as having high significance in evaluation of COVID-19 outcome: IL-6, IL-8, IL-15, and IL-18. Based on the results received, we assume that the highest significance in terms of predicting the outcome of acute COVID-19 belongs to IL-6 and IL-18. Conclusion. Analyzing concentrations of IL-6 and IL-18 before administering treatment may prove valuable in terms of outcome prognosis.

A herd immunity to rubella virus in selected geographical regions

Since 2017, the incidence rate of rubella in the Russian Federation has been below 1 case per million total population. In addition, no circulation of endemic strains of the rubella virus is recorded evidencing about achieving infection elimination phase. In modern conditions, it is important to constantly monitor the level of herd immunity to the rubella virus to identify epidemically significant population groups, especially in countries lacking rubella vaccination or featured with insufficient disease control. Purpose: to study herd immunity to the rubella virus in selected countries in Eurasia and Africa. Materials and methods. Between 2018 and 2021, 15,594 samples of blood sera were tested for IgG and IgM antibodies to the rubella virus from subjects of different ages obtained from regional measles and rubella surveillance centers in the Northwestern Federal District (NWFD) of the Russian Federation, the Republic of Serbia, South Vietnam, and the Republic of Guinea. The Anti-Rubella Virus ELISA (IgМ) and Anti-Rubella Virus ELISA (IgG) (Euroimmun, Germany) test kits were used. Statistical data processing was carried out using the MS Excel, Prizm 5.0 (GraphPad Software Inc.), and Statistica 8.0 (StatSoft Inc.) software package. Results. During the observation period (20182020) the population seroprevalence of the to the rubella virus in the NWFD of the Russian Federation was 96.697.7% and fluctuated slightly both in separate years and among individual age groups evidencing about high coverage of rubella vaccination. In the Republic of Serbia conducting two-fold immunization against rubella the overall seroprevalence rate was lower than in the Russian Federation and comprising 86.8%. The minimum number of IgG-positive sera was recorded in the 24-year-old age group pointing to the shortcomings of routine vaccination. In South Vietnam, children aged 13 years (41.9%) predominated among those recovering from rubella, i.e. the age cohort that should be protected by vaccination at the age of 18 months. No rubella vaccination is carried out in Guinea. The total proportion of seropositive individuals was 75%; herd immunity to the rubella virus was established mainly among children and adolescents, reaching 90% only in the older age group. 30% of unprotected subjects of the most active reproductive age were identified among the females surveyed in Guinea. Conclusion. Insufficient herd immunity to the rubella virus, identified in a number of countries, may contribute to the maintenance of the infectious process and the spread of infection. Globalization contributes to the virus importation into regions being at the stage of measles and rubella elimination. The results obtained suggest about a need to continue efforts aimed at maintaining epidemiological wellbeing regarding rubella in diverse countries of the world.

[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.

Characteristic of herd immunity among the population of Stavropol region amid the COVID-19 epidemic

Introduction. The first pandemic in the 21st century, caused by the pathogenic representative of the coronavirus SARS-CoV-2, began in the Chinese city of Wuhan, where the first outbreak of coronavirus pneumonia was recorded in December 2019. The disease spread so quickly around the world that already on February 11, 2020, WHO was forced to declare a pandemic of the “coronavirus disease 2019” COVID-19. The first case of COVID-19 in the Stavropol Territory was registered on March 20, 2020, and three weeks later, starting from the 15th week of the year, a steady increase in the incidence began, which lasted until the 52nd week. During the study period, the incidence increased from 21.1 to 28.3 per hundred thousand of the population. Growth 1.3 times.

Purpose: to determine the dynamics of population immunity among the population of the Stavropol Territory in 2020-2021. during the period of an epidemic increase in the incidence of COVID-19. Materials and methods. The SARS-CoV-2 study was carried out according to a unified methodology within the framework of the program for assessing the population immunity of the population of the Russian Federation, developed by Rospotrebnadzor with the participation of the St. Pasteur. In total, 2688 people were examined, divided into 7 age groups. In the examined individuals, the level of specific IgG to the SARS-CoV-2 nucleocapsid was determined by the enzyme immunoassay.

Results. The level of seroprevalence among residents of the Stavropol Territory was 9.8%. The largest proportion of seropositive individuals was found in the age groups 1-6 and 7-13 years old (19.2% and 19.7%, respectively). Seroprevalence had no gender differences and ranged from 9.3% to 10.8%. When assessing the distribution of the proportion of seropositive persons in different geographic territories of the region, it was found that the maximum proportion was found in the Kochubeevsky district (23.1%), the minimum in Kislovodsk (7.7%). Among convalescents, the content of specific antibodies to SARS-CoV-2 was noted in 73.3%, which is 7.8 times higher than the average population level. When conducting seromonitoring in the 2nd half of 2020, a 10-fold increase in seroprevalence was recorded, accompanied by a decrease in incidence from the 5th week of 2021. Among asymptomatic volunteers in whom SARS-CoV-2 RNA was detected by the polymerase chain reaction, antibody titers to viruses were found in 78.6%, which corresponds to the seroprevalence of convalescents. The proportion of seropositive persons among those who have come into contact with COVID-19 patients was 16.4%, (1.8 times higher than the average for the population). Out of 262 seroprevalent volunteers, the asymptomatic form of SARS-CoV-2 was detected in 92% of the examined, which indicates a significant role of the number of asymptomatic forms of infection in the epidemic process of COVID-19.

Conclusion. The results of assessing the population immunity of the population of the Stavropol Territory indicate that it has not yet reached the threshold level at which a decrease in the intensity of the COVID-19 epidemic process can be expected. 

Herd immunity to SARS-CoV-2 among the population of the Republic of Belarus amid the COVID-19 pandemic

Objective was to investigate the SARS-CoV-2 collective immunity status of the population of Belarus within the context of the COVID-19 pandemic. Materials and methods. The work was carried out according to the methodology for assessing SARS-CoV-2 population immunity, developed by Rospotrebnadzor Russia and the Ministry of Health of Belarus with the participation of the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The Bioethics Committee of Belarus and the local ethics committee of the St. Petersburg Pasteur Institute approved the study. Selection of participants was carried out using a questionnaire method and online technology (internet, cloud server). Volunteers were randomized into seven age groups (years of age): 1–17; 18–29; 30–39; 40–49; 50–59; 60–69; and 70+. Regional randomization ensured proportional representation of volunteers from each region, and no more than 30 people were included from one enterprise. In accordance with manufacturer instructions, blood plasma samples were analyzed for: IgG antibodies (Abs) to the SARS-CoV-2 nucleocapsid (Nc) using a quantitative ELISA test system; and IgG Abs to the receptor binding domain (RBD) of the SARS-CoV-2 S (spike) surface glycoprotein using a qualitative ELISA test system. Statistical processing was carried out using Excel 2010 and other software. Statistical differences were designated as significant when p 0.05, unless otherwise indicated. Results. The level of seroprevalence, in terms of Abs to Nc among the Belarusian population, was 38.4% (95% CI 37.6–45.4). The highest Ab levels were found among individuals in older age groups (50-70+ years old). The lowest were found in children 1–17 years old and in young people 18–39 years old The distribution of seroprevalence across Belarusian regions was relatively homogeneous, with the exception of the Minsk Region, where a statistically significant decrease in the indicator was noted. In terms of profession, the largest share of seropositive individuals was found among transportation workers; the smallest was found in business. The moderate COVID-19 incidence has not led to a dramatic increase in the number of contacts. The base reproduction number (R0) was 1.3. In the Republic of Belarus, there was a moderate level of asymptomatic COVID-19 among seropositive individuals (45.3% [95% CI 44.0–46.7]). This form of infection was observed most often among children aged 1–17 years old (65.0% [95% CI 61.3–68.6]). In parallel with seroprevalence assessment, SARS-CoV-2 vaccination was carried out. We used two vaccines: Gam-COVID-Vac (also known as Sputnik V, developed by Gamaleya National Center for Epidemiology and Microbiology, Russia); and BBIBP-CorV (Sinopharm, PRC). Vaccination against SARS-CoV-2 was accompanied by an increase in the level of anti-RBD Abs (95% [95% CI 94.7–96.7]). Taking into account the vaccination of a subset of the population with BBIBP-CorV, the overall herd immunity, inferred from the analyzed indicators (presence of anti-Nc or anti-RBD Abs), was 47.1% (95% CI 46.3–48.0). Conclusion. COVID-19 in Belarus was characterized by a moderately pronounced course of the epidemic process. The threshold level of herd immunity to SARS-CoV-2 has not yet been reached, as a result of which the conditions for progression of the epidemic remain.

Methodology for assessing herd immunity to the SARS-CoV-2 virus in the context of the COVID-19 pandemic

Serological monitoring of the study of population immunity to the SARS-CoV-2 virus in the context of COVID-19 pandemic is a necessary component in epidemiological surveillance, since population epidemiological wellbeing in a context of COVID-19 is determined by state of population immunity to the SARS-CoV-2 virus. The population herd immunity is the limiting factor in spread of the SARS-CoV-2 virus. Information on the state of population immunity is necessary to make a forecast for development of epidemiological situation, as well as to plan measures for specific and non-specific prevention of COVID-19. In this regard, the study of population immunity during the pandemic is necessary to predict development of the epidemic and identify features of epidemic process in any certain region and in the country in general. In May 2020, the Rospotrebnadzor program “Assessment of population immunity to the SARS-CoV-2 virus in the population of the Russian Federation in the context of the COVID-19 pandemic” was developed taking into account WHO recommendations in the format of a longitudinal cohort study with age stratification: at the first stage, a cohort of volunteers is formed; at the second and subsequent stages, the cohort of volunteers formed at the first stage is subject to examination; the number of stages depends on the epidemiological situation. In addition to age-related randomization while forming a cohort, at the first stage, the principle of population coverage uniformity was observed, the participation of volunteers from one institution was excluded, and the use of donated blood or patient blood from medical organizations was excluded. The survey was carried out among 7 age groups of healthy children and adults, regardless present or absent previous COVID-19 disease. Due to the fact that the population study is carried out in the context of COVID-19 pandemic, the optimal timing for collecting biomaterial at each stage is no more than 5–7 days. Questioning, selection of volunteers, their registration for blood donation, as well as processing of the results at the first stage, as well as the implementation of the second and subsequent stages of the Program are carried out only by using cloud service technology. This Program and the technology for its implementation have been successfully tested in 26 regions of the Russian Federation during the implementation of four stages from June 2020 to March 2021. Thus, at present, Rospotrebnadzor has developed a methodology and created an effectively working system of serological monitoring to assess level of herd immunity in different regions of the Russian Federation to predict the epidemiological situation, develop recommendations, and plan vaccination.

[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.

Herd immunity of sars-cov-2 among the population of Kalinigrad region amid the COVID-19 epidemic

Introduction. The COVID-19 pandemic was announced by WHO in February 2020. In the Kaliningrad region, the first case (imported) was registered in early March 2020, the beginning of the epidemic increase fell on the 14th week. 2020, and the peak incidence was reached in the 22nd week of the year, after which there was a steady decrease in the number of cases. The study of population immunity was carried out at the 32nd week during the period of the lowest level of intensity of the epidemic process.

Purpose of the study. Assessment of the assessment of the level of population immunity to the SARS-CoV-2 virus among the population of the Kaliningrad region during the period of the epidemic incidence of the population of COVID-19.

Materials and methods. The study was carried out as part of the first stage of the Rospotrebnadzor program to assess population immunity to SARS-CoV-2 among the population of the Russian Federation. The selection of volunteers for the study was carried out by a questionnaire survey and subsequent randomization. The analysis includes the results of a survey of 2675 people. The number of volunteers in age groups ranged from 314 to 493 people. The results obtained were processed by the methods of variation statistics.

Results. The results obtained showed that the average seroprevalence in the population was 50.2%, while the highest seroprevalence was found in the child age group 1-17 years (66.9%) and among persons aged 18-29 (57.0). No significant gender differences were found (men – 48,3 ± 1,6%, women – 51,1 ± 1,1%). The distribution of the proportion of seropositive people in the settlements of the region varied from 33,9% to 59.6%. The largest share of seroprevalence in the representative samples was found among people engaged in art / creativity (55,3%), the smallest – among educational workers (42,0%). Among COVID-19 convalescents, the level of humoral immunity reached 94,6%. Most of the seropositive volunteers (95,2%) did not have any symptoms of COVID-19, that is, they belonged to the category of asymptomatic carriers.

Output. The results of a survey of a representative cohort of volunteers in the Kaliningrad region showed that they are characterized by a high level of population immunity, which makes it possible to expect a decrease in.

Distribution of SARS-CоV-2 seroprevalence among residents of the Republic of Tatarstan during the COVID-19 epidemic period

In late 2019, there were reports of an outbreak of infection caused by a new strain of beta coronavirus SARSCoV-2, the WHO identified the disease as coronavirus disease 2019 (COVID-19). In Tatarstan, the first case of COVID-19 was diagnosed on March 16, 2020, it was an imported case from France. The period of increase in the incidence lasted during the 12th to the 19th week, when the highest rate was recorded, amounting to 16.7 per 100 thousand population. Subsequently, a statistically significant decrease in the incidence was noted. Seroprevalence study was conducted at week 27 (8th week of decline of morbidity).

The purpose of the seroepidemiological study was to measure the level and to identify the structure of herd immunity against the SARS-CoV-2 virus among the population of the Republic of Tatarstan during the rapid spread of the COVID-19 outbreak.

Materials and methods. The selection of volunteers for the study was carried out by the method of questionnaires and randomization by random sampling. The exclusion criterion was active COVID-19 infection at the time of the survey. 2,946 people were examined for the presence of specific antibodies to SARS-CoV-2. The age of the surveyed volunteers ranged from 1 year to 70 years and older.

Results. The results of the study showed that in the Republic of Tatarstan during the period of COVID-19 incidence, there was a moderate seroprevalence to SARS-CoV-2, which amounted to 31.3%, against the background of a high frequency (94.5%) of asymptomatic infection in seropositive individuals who did not have a history of past COVID-19 disease, positive PCR result and ARVI symptoms on the day of the examination. The maximum indicators of herd immunity were established in children aged 7–13 years (42.0%), children 14–17 years old (40.3%), with a simultaneous decrease in seroprevalence in persons aged 70 and older (24.0%). In different regions of the Republic of Tatarstan, there was a wide variation in seropositivity results from the minimum in the Zainsky district (8.6%) to the maximum in the Arsky district (74.3%). In 21 out of 38 surveyed districts, the results were unrepresentative due to the small sample size. In COVID-19 convalescents, antibodies are produced in 83.3% of cases. In persons with a positive result of the PCR analysis carried out earlier, antibodies were detected in 100% of cases. Among the volunteers who had contact with patients with COVID-19, the proportion of seropositive is 37%

Conclusion. The dynamics of seroprevalence among the population of the Republic of Tatarstan can be qualified as positive, the results obtained can be used to develop a forecast for the development of the epidemiological situation, as well as to plan measures for specific and non-specific prevention of COVID-19.

[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.

[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.

Variety of the hepatitis B virus genovariants in the military

Aim. To estimate the distribution of genotypes and subgenotypes of the hepatitis B virus among military personnel with chronic viral hepatitis B. Materials and methods. The work used samples of blood plasma and biopsy material obtained from 90 active or retired military personnel with chronic viral hepatitis B with various degrees of fibrosis undergoing treatment in St. Petersburg. Primary detection of HBV was carried out by isolating nucleic acids (NK) from the blood plasma using the «AmplePrime Ribo-prep» commercial kit (FBIS CRIE, Moscow). Specific primers were used for the amplification and sequencing reaction. Overlapping primer pairs were used, jointly flanking 1475 base pairs (bp) fragment, including the recommended for HBV genotyping the 1169 bp Pre-S1/Pre-S2/S. Results. Among 90 samples from patients with chronic viral hepatitis B from different regions of the Russian Federation, HBV subgenotypes are represented in the following ratios: D2 = 45.6% (n=41), D1 = 32.2% (n=29), D3 = 13.3% (n=12), A2 = 6.7% (n=6), D4 and A1 by 1.1%, respectively. The distribution of HBV subgenotypes from the North Caucasian federal district (D1 – 63.6%, D2, D3, D4, A2 – by 9.1%) was significantly different from the distribution among patients from the Central and North-Western federal districts (D1-20, 9%, D2 – 58%, D3 – 16.3%, A2 – 4.8%) (χ2=11,9приp=0,0076, df=3). Uncharacteristic for the Russian Federation subgenotypes D4 and A1, representing single imported cases. The tendency to shift the distribution of genovariants due to imports of the corresponding HBV subgenotypes from other countries, including the Central Asian countries, is discussed. Conclusion. A systematic study of the HBV isolates phylogeny provides new information about the HBV subgenotypes distribution among certain population groups, including military personnel.

THE PREVALENCE OF OCCULT HEPATITIS B AMONG HBSAG-NEGATIVE PERSONS WITH HIV IN VELIKY NOVGOROD

Aim: to estimate the prevalence of the occult hepatitis B virus among HIV-infected patients with the virological ineffectiveness of antiretroviral therapy in Veliky Novgorod. Materials and methods. Blood plasma samples from 76 HBsAg-negative HIVinfected patients with virological inefficiency of antiretroviral therapy from Veliky Novgorod were used in the work. For the detection of the hepatitis B virus, nucleic acids were isolated using the commercial kit AmplePrime Ribo-prep. For amplification and sequencing, overlapping pairs of specific primers were used, jointly flanking a 1475 base pair fragment including the 1169 base pair Pre-S1/Pre-S2/S region recommended for genotyping the hepatitis B virus. Results. Among 76 samples of hepatitis B virus DNA, 44 samples were found, which was 57,89%. None of the patients had HBsAg, and 6 patients (13,63%) had HBcor IgG and HBe IgG antibodies. On the basis of phylogenetic analysis, it was shown that only genotype D, which is the most common genotype of the hepatitis B virus in the Russian Federation, was detected in the examined group. The subgenotype D2 (47,72%) prevailed in comparison with the subgenotype D1 (34,09%) and the subgenotype D3 (18,18%). The distribution possible ways of the subgenotype D1 hepatitis B virus, which is uncharacteristic for the region, are discussed. Only one isolate of hepatitis B virus with mutations of drug resistance to nucleotide / nucleoside analogue therapy has been identified — amino acid substitution in the polymerase gene of the virus (L180M, M204V) associated with the development of resistance to lamivudine, entecavir, telbivudine and tenofovir. Conclusion. The high prevalence of occult hepatitis B among HIVinfected patients indicates a lack current tests for the diagnosis of chronic HBV infections. The identification of occult hepatitis B in HIV-infected individuals seems appropriate for timely treatment of patients and requires the use more sensitive methods.

[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.

[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.

[Intrathecal immunoglobulin production in the diagnosis and differential diagnosis of multiple sclerosis]

The evaluation of diagnostic significance of different immunological tests for intrathecal immunoglobulin production is summarized on the historical basis of investigation of patients with inflammatory, demyelinating and other neurological disorders. The assessment of cerebrospinal fluid lost its previous significance in the 2010 revision of diagnostic criteria for multiple sclerosis. Nowadays, it is used only for the diagnosis of primary progressive multiple sclerosis. Nevertheless, the requirements of the analysis of the cerebrospinal fluid are increasing due to subtle, subclinical and atypical cases of multiple sclerosis as well as undetermined demyelinating disorders. Intrathecal humoral immune response may be pathogenic in multiple sclerosis as suggest immunological data and effectiveness of anti-B cells treatment. Based on these tests, it is useful, to differentiate subgroups of patients and to evaluate different effects of treatment in perspective.

[The optimization of techniques complex of serologic diagnostics of connective tissue systemic diseases]

The connective tissue systemic diseases originate from pathologic process following with antinuclear antibodies emergence. To detect these antibodies a significant number of diagnostic tests and techniques has been applied. Besides that, there is no conventional algorithm of antinuclear antibodies diagnostic. To detect antinuclear antibodies a two-fold diagnostic algorithm was applied In the capacity of screening techniques the indirect immunofluorescence technique was applied to the cells of line Hep-2 (antinuclear factor) and detection of antibodies to extractable nuclear antigen. The second stage of diagnostic included the detection of content of more specific antinuclear antibodies using the Lineblott method and the double-helical DNA antibodies. The blood serum from 981 patients with suspected connective tissue systemic diseases, 115 patients with systemic lupus erythematous and 57 healthy individuals was analyzed. The levels of antinuclear factor, nuclear antigen antibodies and double-helical DNA antibodies were detected. The antinuclear factor was detected in 84% and 86% of cases, double-helical DNA antibodies in 55% and 39% of cases depending of reagents using in detecting these characteristics. Among healthy individuals, antinuclear factor was detected in 5% (1/20) of blood serum samples in titers less than 1:160. In the group of patients with suspected connective tissue systemic diseases, antinuclear factor was detected in 48% (474/981) of cases and extractable nuclear antigen in 20% (326/981) of cases. The Lineblott test was positive in 33% (326/981) of patients with suspected connective tissue systemic diseases. Among antinuclear factor positive patients nuclear antigen antibodies were detected in 36% (171/474) and the Lineblott test was positive in 63% (298/474) of cases. Among antinuclear factor negative patients but positive under anti-nuclear antigen identification, the Lineblott test was positive in 6% (28/507) of cases. The two-fold algorithm of nuclear antigen testing is an effective technique to be applied in the clinical diagnostic laboratory. The results of effectiveness of this algorithm demonstrated that this method can ensure 33% of cost savings of testing individuals with higher incidence of diseases.

[The analytic and diagnostic characteristics of the national test system detecting cyclic citrullinated peptide antibodies]

The clinical signifcance of serodiagnostic assay of rheumatoid arthritis increased nowadays. This is a reason to include the citrullinated antigens' antibodies into the new criteria of diagnostics ACR/EULAR 2010. The approbation of national test system detecting the cyclic citrullinated peptide antibodies was implemented. The analysis was applied to 211 blood serum samples taken of 50 blood donors, 60 patients with rheumatoid arthritis, 66 patients with other rheumatoid diseases. In addition, 35 samples were concurrently analyzed with the comparative test system (CCP2 Euroimmun, Germany). The referential meanings of standard limits were established on the basis of results of study of samples taken from healthy blood donors. When the standard limit was less than 10 arbitrary units the sensitivity made up 75% and the specificity--87.9%. In the case of higher values of citrullinated antigens' antibodies which are more than 15 arbitrary units, the sensitivity made up 68% and the specificity--93.1%. The results of comparing with the comparative test system characterized by high convergence made up 94% (33 out of 35), but the comparative test system detected citrullinated antigens' antibodies in 2 samples. The positive qualitative results of both methods analysis of autoantibodies weakly correlated with one another (r = 0.14). The results testify that the parameters of national test system correspond to the publication data concerning the second generation methods of cyclic citrullinated peptide antibodies detection though yield to the best foreign analogues.

[A method for differential identification of group C and G streptococci with PCR]

The paper describes a rapid method for PCR identification of Groups C and G streptococci (Streptococcus dysgalactiae subspecies equisimilis, Streptococcus constellatus, and Streptococcus anginosus) that cause human disease. Species-specific regions of the cpn60 gene encoding heat shock protein GroEL (HSP60) were chosen as markers for PCR diagnosis; three pairs of primers were constructed for these regions, each of which was peculiar to the specific type. The method was tested on a large collection of pathogenic streptococci of different serogroups isolated from man and animals; its specificity was shown to identify S. dysgalactiae subsp. equisimilis, S. constellatus, and S. anginosus. The proposed method has all benefits of PCR-based techniques, which enables it to be used for the purposes of molecular epidemiology.

[Symptomatic epilepsy in inflammatory demyelinating diseases]

Based on the own observations, we have summarized the features of symptomatic epilepsy in multiple sclerosis and conducted a clinical analysis of the most diagnostically difficult cases of inflammatory and demyelinating diseases in which epilepsy was the major clinical syndrome. The cases of post-infectious acute disseminated encephalomyelitis, idiopathic cerebral angiitis, Rasmussen's encephalitis are reviewed. Peculiarities of MRI structural brain lesions in these patients are discussed. The use of additional laboratory studies, including a study of cerebrospinal fluid, is considered.

[Recombinant fragments of conservative proteins of group B streptococci as a basis of specific vaccine]

AIM

The study devoted to problem of using of recombinant fragments of group B streptococci (GBS) conservative proteins for induction of immune response against streptococcal infections. Two recombinant polypeptides (ScaAB and-ScpB1) corresponding to immunogenic epitopes of two surface GBS proteins ScaAB and C5a-peptidase, which are presented in other streptococcal species, were studied. The objective of the study was to assess specificity and protective activity of mentioned polypeptides against homologous and heterologous strains of pathogenic streptococci from different groups.

MATERIALS AND METHODS

Strains of Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus agalactiae were used in the study. Array of used methods included opsonophagocytic test as well as active and passive protection of experimental animals against streptococcal infection.

RESULTS

It was shown that antibodies specific to studied polypeptides opsonized several strains of group A and B streptococci as well as pneumococci. Immunization of mice with ScpB1 polypeptide resulted in more rapid recovery of animals from challenge systemic group B streptococcal infection. Antisera specific to both polypeptides provided passive protection of animals from infection caused either GBS or GAS.

CONCLUSION

Obtained data confirm the feasibility to use recombinant fragments of several GBS conservative proteins in vaccine for induction of protection against infections caused by different species of pathogenic streptococci.

[Molecular-genetic comparison of Streptococcus pyogenes strains types emm1 and emm12 on prophage genes repertoire]

AIM

Molecular analysis of Streptococcus pyogenes types emm1 and emm12 genomes on the presence of genes belonging to prophage DNA.

MATERIALS AND METHODS

Thirty-one strains of S. pyogenes type emm1 and 22 strains of S. pyogenes type emm12 were objects of the study. Polymerase chain reaction with special primers for detection of 24 phage genes was used in the study.

RESULTS

Prevalence of phage genes in strains of different emm types was assessed. The following phage genes were most frequently detected: speA, speC, ssa genes for emm1 type and speC and speH for emm12 type. On the basis of the study, 19 different profiles of phage genes were identified.

CONCLUSION

The study allowed to identify not only differences but also similarities between strains of emm1 and emm12 types on prophage gene repertoire in bacterial genome. Presence of similarities allows to assume the possibility of circulation in the studied region similar or identical bacteriophages between streptococci group A (SGA) strains of different emm types.

[Clinical significance of functional variants of matrix metalloproteinase genes in thyroid cancer]

Under analysis were results of genetic investigations of 105 patients with thyroid cancer (TC) treated from 2004 through 2007 in the St. Petersburg City Center of surgery and oncology of the endocrine system organs. The patients' age was from 17 to 80 years (mean age 51.6 +/- 1.9 years). The influence of functional variants of matrix metalloproteinase genes in TC was determined. A reliable correlation was noted between certain gene markers and TC patients' age. An association was revealed between matrix metalloproteinase-3 5A (more active allele) and size of the tumor. A reliably decreased frequency of hyperactive genotype MMP-1 2G was detected in a group of women with metastatic forms of papillary cancer as compared with patients without metastases. It was shown that MMP genes could be a substantial factor of slowing down the rate of malignant growth and invasive properties of cancer of the thyroid gland.

[Detection of infectious agents in heart valves during endocarditis using PCR technique]

Infectious endocarditis can be caused by various microorganisms. Diagnostics of local infection by microbiological methods is not always effective. For that reason we performed a study aimed for direct detection of potential infectious agents by polymerase chain reaction in patients' heart valve tissue. DNA of infectious agents was revealed in 72% of heart valve tissue samples from patients with septic endocarditis; in studied samples, along with bacterial DNA, herpesviruses' DNA was detected. Obtained results confirm the presence of infection, which allows to perform specific diagnostics of infectious complications after implantation of prosthetic cardiac valves.

[Chronic HCV-infection and expression of mRNA of CC-chemokines and their receptors]

The aim of this study was to evaluate some patterns in expression of CC-chemokines (MIP-1alpha, MIP-1beta, MCP-1, RANTES) and their receptors (CCR1, CCR2, CCR3, CCR5) in peripheral blood leukocytes and liver biopsy samples from 21 patients with chronic hepatitis C. 10 healthy subjects were included in the control group. In patients with chronic HCV-infection significant increase of MCP-1 mRNA in liver tissue was observed as the disease progressed. Moreover, content of MCP-1 mRNA was significantly higher in liver as compared with blood. Level of MCP-1 mRNA in liver was directly related with histological changes. Levels of mRNA of CCR1, CCR2, CCR3, and CCR5 in blood of patients with minimal histological manifestations of chronic HCV-infection were significantly lower than in patients with more marked lesions. Expression of CCR1 and CCR5 mRNA in blood was directly correlated with histological activity index and degree of fibrosis. Conducted study demonstrates that progression of chronic hepatitis C is realized through local activation of MCP-1 mRNA synthesis leading to systemic response which manifested by increase of expression of CCR1, CCR2, CCR3, and CCR5 in peripheral blood leukocytes.

[Efficacy of local use of recombinant interferon alpha-2 preparations in combined treatment of recurrent respiratory papillomatosis]

Clinical-immunological examination of 41 patients with recurrent respiratory papillomatosis (RRP) included determination of phenotype CD3, CD4, CD8, CD16, CD25, CD56, HLA-DR in peripheral blood by flow cytofluorimetry, the levels of IFN-gamma, TNF-alpha, GM-CSF, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13 in the laryngeal secretion by multiplex immunoassay. Interferon inhalation therapy was conducted to prevent recurrence in 23 patients after surgical treatment and in 18 patients as monotherapy. The efficacy of the monotherapy was 45.5%. Treatment with IFN-alpha raised the levels of cytokines modulating an immune response by Th1-type (IFN-gamma, IL-12, IL-2) and GM-CSF, and reduced the levels of IL-4, IL-10 and IL-13. Local treatment with recombinant IFN-alpha is effective in aggressive RRP. As prognostic markers of the treatment efficacy may serve baseline high levels of TNF-alpha and IL-4/IFN-gamma index in laryngeal secretion. Treatment efficacy can be assessed by raise of IFN-gamma, IL-2 and IL-12 in combination with reduction of IL-4/IFN-gamma index.

[PCR detection of periodontal bacteria and Streptococcus mutans in the biological samples from the oral cavity]

The paper describes an optimized technique for DNA isolation from the Streptococcus mutans cultures and from the clinical samples including proteinase K treatment and detergent lysis, followed by sorbent-based enrichment. This technique was employed for isolating DNA from the periodontal bacteria Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Bacteroides forsythus. A multiplex PCR technique was adapted for large-scale studies of clinical samples. An original PCR method was developed for the semiquantitative detection of Str. mutans, showing the sensitivity of 100 genome copies per reaction. Extensive studies of approximately 2,000 individuals have demonstrated that these methods are applicable to the study of the dental and gingival microflora in the biological sample from the oral cavity of persons with dental diseases from various age groups.

[Immunogenicity of modified by dextran recombinant fragment of Bac protein of group B streptococci]

Opportunity to increase of immunogenicity of recombinant polypeptide P6 constructed on the basis of surface protective Bac protein by its chemical conjugation with dextran (D) 40 was studied. 3 preparations with different quantity of protein and polysaccharide components were obtained. Their testing with standard serum showed that antigenic determinants of the polypeptide were preserved although partly enclosed and structure of antigenic determinants did not significantly changed. On the model of subcutaneous immunization of mice it has been shown that two preparations--P6D2 and P6D3--have improved immunological characteristics. Conjugation of polypeptide P6 with dextran let to increase of immune response to P6 and affinity of P6-specific antibodies. Injection of nonconjugated P6 and dextran mixture showed that free dextran is not immunogenic and it suppress synthesis of P6-specific antibodies without effect on their affinity. Intranasal administration of nonconjugated P6 did not lead to P6-specific IgG in serum. After conjugation with dextran polypeptide P6 was recognized as an antigen and stimulated production of small quantity of antibodies. Technological process of chemical binding of protein antigen with polysaccharides, which let to regulate protein and polysaccharide components ratio, can be the effective method to increase immunogenicity of recombinant polypeptides.

[Streptococcus agalactiae sak0192 gene contains direct repeats and spacers that are genetic markers for characterizing the strains]

A new approach to differentiation of the Streptococcus agalactiae strains was suggested. The approach is based on the nucleotide polymorphism of the sak0192 gene containing variable number of 16 bp direct repeats and 44 bp spacer regions in different S. Agalactiae strains. In general, the direct repeats were identical, while the spacers were variable. Overall, the structure of the sak0192 gene of S. Agalactiae was analogous to direct repeat cluster of Mycobacterium tuberculosis and Streptococcus pyogenes. The applicability of the sak0192 gene polymorphism as a novel genetic marker to identification of S. Agalactiae and differentiation of the strains was demonstrated.

[Optimization of a method for determination of complement activity from 50% hemolysis of sensibilized red blood cells]

The method for determination of compliment activity from 50% hemolysis of sensitized blood cells (CH5) was modified in accordance with the recommendations of the International Clinical Chemistry Association, which could reduce the consumption of reagents, enhance the accuracy and reproducibility of results. The activity of CH50 was calculated for each serum sample by regression analysis, by graphically reflecting the results and by assessing the quality of each performance. The sigma-deviation method was used to calculate the normal CH50 ranges (55-160 conventional units) whose values were in compliance with the international standards. A series of experiments were made to assess the reproducibility of results. To evaluate the diagnostic informative value, the authors analyzed serum samples from 119 persons: 49 apparently healthy individuals, 74 patients with allergic diseases that are generally unattended by hypocomplementemia (Group 1) and 76 with disease the risk of which is increased in the presence of complement system defect (Group 2). Group 1 patients were those who had bronchial asthma or utricaria; Group 2 patients were those who had systemic lupus erythematosus, scleroderma, rheumatoid arthritis, chronic glomerulonephritis, acute glomerulonephritis, chronic furunculosis, chronic tonsillitis, or necrotic vasculitis. In Group 1, the value of CH50 was similar to that in the group of donors (108.0 +/- 3.1 and 105.1 +/- 3.8, respectively; p = 0.565), but it significantly differed from its mean value (91.6 +/- 5.1) in Group 2 (p = 0.00724). The difference in CH50 was also significant in the group of donors and Group 2 (p = 0.0349).