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Heart transplant patients are at an increased risk of COVID-19 infection adverse outcomes because of underlying immunosuppression and concomitant comorbidities. To date, all large-scale randomized controlled trials for various COVID-19 vaccines have excluded solid organ transplant recipients. Therefore, the efficacy and safety of coronavirus infection prevention using COVID-19 vaccines in transplant heart patients has not been sufficiently studied. In this research, the evaluation of virus-specific immunological reactions after vaccination (double Vero Cell vaccination and Sputnik Light booster vaccination) in heart transplant patients has been carried out. In vaccinated heart transplant individuals who did not have a history of COVID-19, starting from 4–6 months after the 2nd dose of the vaccine, an increase in antibodies to S protein level of was observed, while maintaining statistically significant differences for 9–12 months after vaccination (regardless of whether with or without booster vaccination). However, the concentration of antibodies remained low, and 37% of patients detected no antibodies. In vaccinated heart transplant individuals following the previous COVID-19 infection, as compared to seronegative patients, post-vaccination immunity is accompanied by maintaining a high level of virus-specific IgG antibodies to the S protein of the SARS-CoV-2 virus in the dynamics of the post-vaccination period with a statistically significant increase of these antibodies by 9–12 months after booster vaccination. The specific cellular response (according to the assessment of CD3⁺154⁺ and CD3⁺IFNγ⁺ TNFα⁺ cells) to the S protein of the SARS-CoV-2 virus remained low throughout the entire follow-up period, was recorded in 5–40% of heart transplant patients and statistically significant changes in the number of spikereactive lymphocytes were observed in patients with a history of COVID-19 by 4–6 months after administration of the 2nd dose of the vaccine. This, together with the results of the assessment of the humoral response, indicates a more pronounced post-vaccination immunity in patients with a hybrid immunity. While developing a methodology for assessing the risk and benefit of a vaccination strategy for individual heart transplant patients, clinical efficacy, ongoing monitoring of rare serious adverse events, and data on vaccine immunogenicity should be taken into account.

Postmortem diagnosis of enzootic bovine leukosis is made on the basis of the results of tests of biological materials from emergently slaughtered or fallen animals using pathomorphological, histological and molecular genetic methods that have some disadvantages. Results of post-slaughter diagnostic tests for bovine leukosis with enzyme-linked immunosorbent assay are described in the paper. For this purpose, 83 swabs were collected from different carcass parts including 71 swabs from carcasses of the animals that were not pre-slaughter tested and 12 samples from the carcasses of the animals that were pre-slaughter tested with immunodiffusion assay and found bovine leukemia virus-seronegative (control samples). Sterile scalpels, cotton wool, 5 mL tubes with caps were used for swab collection. The samples were taken from incisions in carcasses and internal organs of slaughtered animals with sterile cotton-wool swabs and placed in single-use tubes. Distilled water (or isotonic solution – 0.85% NaCl) was added to the tubes with samples, 0.1 to 0.2 mL per tube depending on the sample size, and the tubes were left at room temperature (22–26 °С) for 1.5–2.0 hours and regularly shaken. Resulting homogeneous substrate was used for enzyme-linked immunosorbent assay carried out in accordance with the instructions for the test-kit for detection of antibodies against bovine leukemia virus. Specific antibodies to bovine leukemia virus gp51 antigen were detected in 6 (8.5%) out of 71 swabs subjected to the laboratory tests. Therewith, the antibodies were detected only in 3 swabs (4.2%) when the swabs were tested with immunodiffusion assay. All 12 control samples from animals that were pre-slaughter tested and found seronegative were negative when tested with enzyme-linked immunosorbent assay. Therefore, the above-said serological method can be used for post-slaughter diagnosis of bovine leukosis together with conventional methods.

The role of Mycoplasma canis in canine fertility disorders is still poorly understood. As infection is often asymptomatic, there is an increasing need for appropriate diagnostic methods and treatment plans that would allow the reliable detection of M. canis infection and rapid alleviation of infection symptoms in affected dogs. In this study, we included 14 dogs with fertility problems and 16 dogs without fertility disorder signs. We compared clinical examination data and selected laboratory parameters (hematology and biochemistry) between the groups. We performed PCR-based detection of M. canis and 16S rRNA gene-based microbiota profiling of DNA isolated from vaginal and preputial swabs. Dog sera were tested for the presence of M. canis-specific antibodies. Hematological and selected biochemical parameters showed no differences between groups. PCR-based detection of M. canis in the samples was consistent with the results of 16S microbiota profiling. Several other bacterial taxa were also identified that could potentially be involved in different fertility disorders. Serological methods were not accurate enough since high cross-reactivity rates were observed. In the future, more accurate and efficient methods will be needed to determine the role of M. canis and its true role in the pathogenesis of specific fertility disorders in dogs. [ABSTRACT FROM AUTHOR]

Many pathogens are related to carcinogenesis. Chronic inflammation, as a result of persistent infection, leads to DNA damage, higher expression of oncogenes, decreased apoptosis and immunosuppression, which are some of the reasons for cancer induction. Among parasites, Schistosoma, Opistorchis and Clonorchis are recognised as infectious agents which contribute to cancer. A relationship between Anisakis and cancer was hypothesised because cellular responses to Anisakis products could result in inflammation and DNA damage. Previous research has shown a decrease in CD8+ γδ T-cells and an increase in αβ and γδ T-cell apoptosis in colon cancer (CC) samples. Ninety-two CC patients and 60 healthy subjects were recruited. γδ and αβ T-cells were analysed, and their apoptosis was evaluated. Anti-Anisakis antibodies were tested in sera from CC patients and controls. Anti-Anisakis IgG, IgM, IgA and IgE antibodies were significantly higher in CC patients. A significant increase in anti-Anisakis IgA levels was observed in patients with angiolymphatic invasion. The number of all γδ T-cells, as well as CD3+ CD4+ αβ T-cells, was significantly lower in CC patients. The apoptosis of all T-cells was significantly increased in patients with CC. We observed a significantly higher percentage of anti-Anisakis IgE positive patients having a deficit of CD3+ γδ T-cells. Our results suggest a relationship between Anisakis and CC. [ABSTRACT FROM AUTHOR]

Background and Aim: Salmonella abortion in mares is caused by Salmonella enterica subspecies enterica serovar abortus equi infection and is characterized by premature (abortion) or non-viable fetus birth. Although all horses are susceptible to infection, the condition is more often clinically manifested in pregnant mares, with most abortions recorded in young females. In addition, nonspecific clinical disease signs and poorly sensitive and effective bacteriological diagnostic methods hinder rapid and reliable infection diagnoses. Immunochemical methods such as enzyme-linked immunosorbent assay (ELISA) and immunochromatography assays can facilitate effective and rapid diagnoses. However, they require highly specific and active antigens and antibodies. This study aimed to generate a recombinant S. enterica outer membrane protein X (OmpX) and evaluate its suitability for serological diagnosis of Salmonella abortion in mares. Materials and Methods: Outer membrane protein X from the S. enterica antigen was synthesized de novo and expressed in Escherichia coli using the pET28 vector. Transformed E. coli cells were cultured under different conditions to detect recombinant OmpX (rOmpX) expression, and rOmpX purification and refolding were both conducted using metal affinity chromatography. Refolded and purified rOmpX was characterized by western blotting, liquid chromatography with tandem mass spectrometry, and ELISA. Results: After optimized rOmpX expression, a 23 kDa molecular weight protein was identified. Amino acid sequence analysis using Mascot program suggested that these peptides were the OmpX protein from S. enterica. High specificity and diagnostic efficiency were recorded when rOmpX was used in ELISA against 89 serum samples from aborted and contact mares. Conclusion: Recombinant outer membrane protein, in comparison to the O antigen, demonstrated better diagnostic characteristics against sera from mares who aborted and contact horses. [ABSTRACT FROM AUTHOR]

The implementation of animal health improvement and disease prevention activities with respect to bovine leukosis involves a need for timely detection of cattle infected with bovine leukaemia virus (BLV) on livestock farms. That is why early diagnosis using more sensitive and highly accurate methods is of particular importance. The paper presents the results of cattle serum tests for bovine leukosis with enzyme-linked immunosorbent assay (ELISA) and immunodiffusion (ID), as well as the comparative assessment of their effectiveness. A total of 440 cattle blood samples were subjected to serological testing with immunodiffusion; 37 (8.4%) of them tested positive for bovine leukaemia virus. The cattle blood samples were submitted from the Kumtorkalinsky (127), Karabudakhkentsky (122), Buynaksky (89) Raions, from Makhachkala (56) and Kaspiysk (46). Seropositivity was 17 (13.4%), 8 (6.6%), 5 (5.6%), 4 (7.1%) and 3 (6.5%), respectively. For the comparative assessment of the diagnostic tests, 100 (5 ID-positive and 95 ID-negative) serum samples were taken and tested with ELISA. As a result, specific antibodies against BLV gp51 antigen were detected in 4 ID-negative serum samples. All ID-positive serum samples also tested positive with ELISA. All in all 9 virus carriers were detected with ELISA, that is 44.4% more than with immunodiffusion. Thus, enzyme-linked immunosorbent assay is characterized by a higher sensitivity, as compared with immunodiffusion, and allows for improved detection of infected animals. However, alongside the advantages, this technique has certain disadvantages, one of which is the high price of the diagnostic test kit for anti-BLV antibody detection and the equipment required.

Background. There are many aspects of the development of immunity to the SARSCoV-2 virus, that remain poorly understood, like the influence of age-related characteristics on the intensity of immunity and the course of the disease. Studies of the state of immunity are widely used, mainly in the adults. But questions of the patho- and immunogenesis in children remain unsolved. Determining the nature of seroconversion of antibodies to SARS-CoV-2 in this age group is important information for serological monitoring for targeted immunoprophylaxis of the population and forecasting the epidemic situation in the region.The aim. Evaluation of the dynamics of seroprevalence of specific antibodies to SARS-CoV-2 in children of the Irkutsk region during the pandemic of a new coronavirus infection.Materials and methods. Study was conducted among the child population of the Irkutsk region in the period June 2020 – December 2021 as part of the Rospotrebnadzor project to assess population immunity to SARS-CoV-2 in the population of the Russian Federation. The content of antibodies to SARS-CoV-2 was determined by ELISA using native commercial test systems.Results. Population immunity among the child population of the Irkutsk region was characterized by an upward trend from 7.8 % at stage 1 to 98.4 % at stage 6 of the study. IgG to SARS-CoV-2 remained in 72.8 % and formed in 25.6 % of previously seronegative children. Antibodies were detected in 66.1 % of cases and persisted for up to 10–15 months after COVID-19 infection. The proportion of asymptomatic forms of infection among seropositive volunteers was 69.5 %, which determines the high intensity of the latent epidemic process.Conclusion. The level of seroprevalence was 98.4%. The current results of serological monitoring serve as a scientific basis for adjusting the list and scope of management decisions on the organization of preventive anti-epidemic measures, including vaccination.

Introduction. Yellow fever (YF) remains one of the most common natural focal infectious diseases in the world. In connection with the increasing tourist flow to countries endemic for YF, the discovery of stable populations of Aedes aegypti and Ae. albopictus which are the main vectors of the yellow fever virus (YFV), in the southern regions of Russia, and the fact that in medical institutions in our country it is possible to obtain a live attenuated vaccine against YF, but there is no way to evaluate the effectiveness of vaccination, the question arises of the development and implementation of diagnostic kits for detecting antibodies (AB) to the pathogen by enzyme immunoassay (ELISA). The aim of this study was to develop a method for detecting specific IgG antibodies to the E protein of YFV by ELISA and assessing its diagnostic characteristics. Materials and methods. A specific cDNA was synthesized by reverse transcription on an RNA template of YFV isolated on a cell culture of Aedes albopictus clone C6/36, and a fragment of the genome coding the YFV E protein was amplified and subsequently cloned into the plasmid pET160 (Thermo Fisher Scientific, USA). The resulting gene fragment was used as a DNA template to obtain a recombinant analog of the third domain of the YFV E protein in Escherichia coli cells (BL-21(DE3)). Next, the immunogenicity of the obtained antigen was evaluated and the analysis conditions were optimized. Results. The optimal conditions for the production of the obtained recombinant E protein of YFV were determined, its specificity was confirmed by immunological methods (Western blot and ELISA), sorption buffers and blocking solutions were selected, and sensitivity and specificity of detection of antibodies to YFV using the recombinant antigen were assessed. Conclusion. A method for the detection of specific IgG antibodies to the YFV E protein by ELISA was developed. This diagnostic kit can be used both to study the protective properties of the YF vaccine and to detect imported cases of infection in non-endemic areas.

ABSTRACT In the situation of mass vaccination against COVID-19, few studies have reported on the early kinetics of specific antibodies (IgG/IgM/IgA) of vaccine breakthrough cases. There is still a lack of epidemiological evidence about the value of serological indicators in the auxiliary diagnosis of COVID-19 infection, especially when the nucleic acid results were undetectable. Omicron breakthrough cases post-inactivated vaccination (n = 456) and COVID-19-naive individuals with two doses of inactivated vaccination (n = 693) were enrolled. Blood samples were collected and tested for SARS-CoV-2 antibody levels based on the magnetic chemiluminescence enzyme immunoassay. Among Omicron breakthrough cases, the serum IgG antibody level was 36.34 Sample/CutOff (S/CO) (95% confidence interval [CI], 31.89 to 40.79) in the acute phase and 88.45 S/CO (95% CI, 82.79 to 94.12) in the recovery phase. Serum IgA can be detected in the first week post-symptom onset (PSO) and showed an almost linear increase within 5 weeks PSO. Compared with those of breakthrough cases, IgG and IgA titers of the postimmune group were much lower (4.70 S/CO and 0.46 S/CO, respectively). Multivariate regression showed that serum IgG and IgA levels in Omicron breakthrough cases were mainly affected by the weeks PSO (P

In this article, we report the development of an electrochemical biosensor for the determination of the SARS-CoV-2 spike protein (rS). A gold disc electrode was electrochemically modified to form the nanocrystalline gold structure on the surface. Then, it was further altered by a self-assembling monolayer based on a mixture of two alkane thiols: 11-mercaptoundecanoic acid (11-MUA) and 6-mercapto-1-hexanol (6-MCOH) (SAMmix). After activating carboxyl groups using a N-(3-dimethylaminopropyl)-N'-ethyl-carbodiimide hydrochloride and N-hydroxysuccinimide mixture, the rS protein was covalently immobilized on the top of the SAMmix. This electrode was used to design an electrochemical sensor suitable for determining antibodies against the SARS-CoV-2 rS protein (anti-rS). We assessed the association between the immobilized rS protein and the anti-rS antibody present in the blood serum of a SARS-CoV-2 infected person using three electrochemical methods: cyclic voltammetry, differential pulse voltammetry, and potential pulsed amperometry. The results demonstrated that differential pulse voltammetry and potential pulsed amperometry measurements displayed similar sensitivity. In contrast, the measurements performed by cyclic voltammetry suggest that this method is the most sensitive out of the three methods applied in this research. [ABSTRACT FROM AUTHOR]

This study aimed at investigating the influence of genetic and non‐genetic factors on immune traits to inform on possibilities of genetic improvement of disease resistance traits in local chicken of Kenya. Immune traits such as natural and specific antibodies are considered suitable indicators of an individual's health status and consequently, used as indicator traits of disease resistance. In this study, natural antibodies binding to Keyhole Limpet Hemocyanin (KLH‐NAbs) was used to measure general disease resistance. Specific antibodies binding to Newcastle disease virus (NDV‐IgG) post vaccination was used to measure specific disease resistance. Titers of KLH‐NAbs isotypes (KLH‐IgM, KLH‐IgG and KLH‐IgA) and NDV‐IgG were measured in 1,540 chickens of different ages ranging from 12 to 56 weeks. A general linear model was fitted to determine the effect of sex, generation, population type, phylogenetic cluster, line, genotype and age on the antibody traits. A multivariate animal mixed model was fitted to estimate heritability and genetic correlations among the antibody traits. The model constituted of non‐genetic factors found to have a significant influence on the antibody traits as fixed effects, and animal and residual effects as random variables. Overall mean (±SE) concentration levels for KLH‐IgM, KLH‐IgG, KLH‐IgA and NDV‐IgG were 10.33 ± 0.04, 9.08 ± 0.02, 6.00 ± 0.02 and 10.12 ± 0.03, respectively. Sex, generation and age (linear covariate) significantly (p < 0.05) influenced variation across all the antibody traits. Genotype effects (p < 0.05) were present in all antibody traits, apart from KLH‐IgA. Interaction between generation and line was significant (p < 0.05) in KLH‐IgM and NDV‐IgG while nesting phylogenetic cluster within population significantly (p < 0.05) influenced all antibody traits, apart from KLH‐IgA. Heritability estimates for KLH‐IgM, KLH‐IgG, KLH‐IgA and NDV‐IgG were 0.28 ± 0.08, 0.14 ± 0.06, 0.07 ± 0.04 and 0.31 ± 0.06, respectively. There were positive genetic correlations (0.40–0.61) among the KLH‐NAbs while negative genetic correlations (−0.26 to −0.98) were observed between the KLH‐NAbs and NDV‐IgG. Results from this study indicate that non‐genetic effects due to biological and environmental factors influence natural and specific antibodies and should be accounted for to reduce bias and improve accuracy when evaluating the traits. Subsequently, the moderate heritability estimates in KLH‐IgM and NDV‐IgG suggest selection possibilities for genetic improvement of general and specific immunity, respectively, and consequently disease resistance. However, the negative correlations between KLH‐NAbs and NDV‐IgG indicate the need to consider a suitable approach that can optimally combine both traits in a multiple trait selection strategies. [ABSTRACT FROM AUTHOR]

To confirm discrepant SARS-CoV-2-IgG results in four standard assays we applied for the first time a prototype of a coronavirus IgG-line-blot which employs antigens from seasonal coronaviruses, SARS-1 and SARS-CoV-2 combined with avidity testing as a confirmatory tool in a follow-up of five cases including pre-pandemic samples.

Background. Currently, the COVID-19 pandemic in the world and in Russia remains the main event. In this regard, the study of the manifestations of the epidemic process of the new coronavirus infection COVID-19 and the patterns of its development are an urgent area of research. In the fight against this viral disease, an important role is assigned to the study of the development of population immunity to the SARSCoV-2 virus, which will make it possible to assess the dynamics of seroprevalence and the formation of post-infectious humoral immunity, forecasting the development of the epidemiological situation, elucidating the characteristics of the epidemic process, and will also contribute to planning activities for specific and non-specific prevention of the disease.The aim: to determine the dynamics of population immunity to SARS-CoV-2 among the population of the Irkutsk region during the COVID-19 pandemic.Materials and methods. As a part of the Rospotrebnadzor project of assessing population immunity to SARS-CoV-2 in the population of the Russian Federation, the research has being conducted among the population of the Irkutsk region in the periods from June 23, 2020 to July 19, 2020 (Stage 1), from September 16, 2020 to September 25, 2020 (Stage 2), from December 7, 2020 to December 18, 2020 (Stage 3) and from March 8, 2021 to March 14, 2021(Stage 4), taking into account the reacted one recommended by the WHO. The content of antibodies to SARS-CoV-2 was determined by ELISA using a set of tests for human serum or plasma for specific immunoglobulins of class G to the proteins of the SARS-CoV-2 coronavirus.The results. The research of the humoral immunity of volunteers shows that during the period of an epidemic rise in the incidence of COVID-19 in the Irkutsk region, a low level of seroprevalence was formed (Stage 1 – 5.8 ± 0.5 %, Stage 2 – 12.1 ± 0.7 %), and in conditions of a long-term maximum increase in the incidence rate – 25.9 ± 1.0 % (Stage 3) and 46.2 ± 1.2 % (Stage 4). A significant proportion (Stage 1 – 82.2 ± 3.2 %, Stage 2 – 86.1 ± 2.3 %) of asymptomatic forms of infection characterizes the high intensity of the latently developing epidemic process in the first two stages. High levels of IgG in reconvalescents of COVID-19 persisted for an average of 3 to 5 months.Conclusion. The results of assessing the population immunity to the SARS-CoV-2 virus in the population of the Irkutsk region indicate that the seroprevalence level at Stage 4 of the research was 46.2 %. After the disease, on average, 49.5 % of persons did not detect antibodies. The results obtained should be taken into account when organizing preventive measures, including vaccination, and predicting morbidity.

Background. The ongoing COVID-19 pandemic in the world and in Russia remains the main event in 2020. A comprehensive study of the patterns of development and manifestations of the epidemic process of the new coronavirus infection COVID-19 is an urgent line of research. One of the important aspects of the fight against COVID-19 is the study of population immunity to the SARS-CoV-2 virus in order to assess seroprevalence and the formation process of post-infectious humoral immunity to SARS-CoV-2, forecast the development of the epidemiological situation, identify the features of the epidemic process, as well as planning measures for specific and non-specific disease prevention. The aim of the research is to determine the level and structure of population immunity to SARS-CoV-2 among the humans of the Irkutsk region during the COVID-19 epidemic. Materials and methods. As part of the Rospotrebnadzor project to assess population immunity to SARS-CoV-2 in the population of the Russian Federation, research is being conducted among the population of the Irkutsk region in the periods from 06/23/2020 to 07/19/2020 (stage 1), from 09/16/2020 to 09/25/2020 (Stage 2) and from 12/07/2020 to 12/18/2020 (stage 3), taking into account the reacted one recommended by the WHO. The content of antibodies to SARS-CoV-2 was determined by ELISA using a set of tests for human serum or plasma for specific immunoglobulins of class G to the nucleocapsid of the SARS-CoV-2 virus produced by FBUN GNCPMiB Rospotrebnadzor (Obolensk). The results of a research of the humoral immunity of volunteers show that during the period of an epidemic rise in the incidence of COVID-19 in the Irkutsk region, a low level of seroprevalence was formed (stage 1 – 5.8 ± 0.5%, stage 2 – 12,1 ± 0,7%), and in conditions of a long-term maximum increase in the incidence rate ¬– 25,9±1,0% (stage 3). A significant proportion (stage 1 – 81,2±3,2%, stage 2 – 90.9 ±1,9%) of asymptomatic forms of infection characterize the high intensity of the latently developing epidemic process in the first two stages. High levels of IgG in reconvalescents of COVID-19 persisted for an average of 3 to 4.5 months. Conclusion. The results of assessing the population immunity to the SARS-CoV-2 virus in the population of the Irkutsk region indicate that the seroprevalence level at the 3rd stage of the research was 25.9%. After the disease, on average, 41.6% of persons did not detect antibodies. The results obtained should be taken into account when organizing preventive measures, including vaccination, and predicting morbidity.

The serologic diagnosis of coronavirus disease 2019 (COVID-19) and the evaluation of vaccination effectiveness are identified by the presence of antibodies specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this paper, we present the electrochemical-based biosensing technique for the detection of antibodies specific to the SARS-CoV-2 proteins. Recombinant SARS-CoV-2 spike proteins (rSpike) were immobilised on the surface of a gold electrode modified by a self-assembled monolayer (SAM). This modified electrode was used as a sensitive element for the detection of polyclonal mouse antibodies against the rSpike (anti-rSpike). Electrochemical impedance spectroscopy (EIS) was used to observe the formation of immunocomplexes while cyclic voltammetry (CV) was used for additional analysis of the surface modifications. It was revealed that the impedimetric method and the elaborate experimental conditions are appropriate for the further development of electrochemical biosensors for the serological diagnosis of COVID-19 and/or the confirmation of successful vaccination against SARS-CoV-2. [ABSTRACT FROM AUTHOR]

We performed a seroepidemiological survey of the level and structure of population immunity to SARS-CoV-2 among employees of medical institution in the Irkutsk region during the COVID-19 pandemic. Seroprevalence assessment was organized from May 2020 to April 2021. The level of antibodies to SARS-CoV-2 was measured by ELISA. It was found that 139 (46%) of 299 examined workers were seropositive, including 50 (36%) vaccinated against COVID-19, 75 (54%) patients diagnosed with COVID-19, and 14 (10%) asymptomatic cases of SARS-CoV-2. The results obtained should be taken into account when predicting the dynamics of the epidemic process and organizing preventive (antiepidemic) measures, including vaccination. [ABSTRACT FROM AUTHOR]

The global community is experiencing one of the largest infectious disease outbreaks in the 21st century. In the Saratov Region, the first case of new coronavirus infection was confirmed on March 19, 2020.The maximum increase in cases was noted between May 15 and June 30, during that time the total number of infected people in the region increased from 1526 to 6444. Since July 2020, a stable incidence level of new coronavirus infection has been observed in the Saratov Region, without a steady decline.The aim of the study was to assess the status of population immunity to the SARS-CoV-2 virus among residents of Saratov and the Saratov Region under the COVID-19 epidemic.Materials and methods. In the period from June 23 to July 26, 2020, a serological study of blood samples from 3372 volunteers of different age groups was conducted. The content of antibodies to SARS-CoV-2 was determined by ELISA using a set of reagents “ELISA anti-SARS-CoV-2 IgG” produced by the State Scientific Center of Applied Microbiology and Biotechnology of the Rospotrebnadzor (Russia).Results and discussion. In general, the incidence of COVID-19 in the Saratov Region is taking place against the background of moderate seroprevalence to the SARS-CoV-2 virus, accompanied by a high incidence of non-apparent (asymptomatic) forms of the infectious process. The absence of clinical symptoms of the disease, in the context of the limited use of methods for determining the RNA of the SARS-CoV-2 virus in PCR (11 % of the region’s population) makes it difficult to assess the real spread of the virus in the population and to establish the timing of the formation of persistent herd immunity. A low rate of antibody response among individuals with a positive result of PCR analysis, as well as among volunteers who had an infection in May, June 2020, indicates a weak formation of the immune response, or the prevalence of individuals reacting mainly by activating the cellular link of the immune system in the population. The obtained results, although they need to be explained in a number of respects, can be applied to the organization of preventive measures, including vaccination, in the region.

Understanding how older people respond to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical if we are to confront the coronavirus disease 2019 (COVID-19) pandemic and establish effective vaccination strategies. Immunosenescence reduces the ability to respond to neoantigens and may compromise the life of infected individuals. Here, we analyzed the immunological memory to SARS-CoV-2 in 102 recovered patients aged over 60 years several months after the infection had been resolved. Specific memory T lymphocytes against the virus were measured by interferon-γ (IFN-γ) and granzyme B release by ELISpot; memory B-lymphocyte responses were quantified by detection of anti-S IgG1 producer cells by ELISpot and anti-S and anti-N antibodies were determined by enzyme-linked immunosorbent assay (ELISA). Memory T lymphocytes were found in peripheral blood of most of the studied donors, more than 7 months after the infection in some of them. Fewer patients maintained memory B lymphocytes, but antibodies, mainly anti-S, were highly durable and positively correlated with T responses. More robust humoral responses were found in patients who had more severe symptoms and had been admitted to hospital. We concluded that specific immunity against SARS-CoV-2 is effectively preserved regardless of age, despite the great heterogeneity of their immune responses, and that memory T lymphocytes and anti-S IgG might be more durable than memory B cells and anti-N IgG. [ABSTRACT FROM AUTHOR]

To study the seroprevalence of Lawsonia intracellularis among the pig livestock of Ukraine. The research was conducted in the laboratories of the Institute of Veterinary Medicine of NAAS and in pig farms. Were studied 653 samples of pigs’ serum of different age groups from17 pig farms with breeding stock of 40 456 sows. To study seroprevalence was used a test system for enzyme-linked immunosorbent assay based on monoclonal antibodies bioScreen Ileitis Antibody Test ELISA Svanovir®Lawsonia intracellularis (Boehringer Ingelheim Svanova). Serological tests have provided evidence that the pathogen was circulating in the herd. According to the research results, 46.4% of seropositive animals were found. Seropositive pigs were found in all studied farms, namely – among sows – 74.0%, replacement gilts – 79.6%, growing pigs – 2.5% and fattening pigs – 59.8%. The high level of seroprevalence among replacement gilts and sows of the 1st farrowing indicates the circulation of the pathogen in the herd, as well as the manifestation of morbidity in the fattening group, where was the highest rate of positive serum samples. From the 17 examined farms, only one farm was found where no seropositive animals were detected. According to our observations, proliferative enteropathy in pigs of Ukrainian pig farms has signs of chronic course, especially it is common in pig farms that import replacement gilts from abroad, where antibiotics are prohibited or restricted in donor farms. The results of serological tests allowed us to reconfirm that the spread of the disease is increasing in Ukrainian pig farms. Compared to 2015, the percentage of seropositive animals increased by almost 10%. The typical serological profile for Lawsonia intracellularis which is characteristic of our studied farms allowed us to conclude for which age groups of pigs and for which technological period of raising swine it is necessary to develop and implement measures for treatment and disease prevention. To control the disease, it is highly recommended to conduct constant monitoring of the farm’s well-being against ileitis (send, in addition to faecal samples for PCR testing, also serum for ELISA testing).

Background. Currently, during the COVID-19 pandemic, one of the most pressing healthcare problems is to ensure the safety of the population of the Russian Federation. There is insufficient information on the duration and intensity of post-infectious immunity in relation to SARS-CoV-2, especially in case of inapparent (without clinical signs), mild or latent forms of infection.Materials and methods. The study involved 99 volunteers with a laboratory confirmed PCR diagnosis of COVID-19 who were residents of the Irkutsk Region and of other regions of the Russian Federation and arrived to work in Bodaybo on a rotational basis. Also the study included 50 conditionally healthy people living in Irkutsk who had negative PCR results for SARS-CoV-2 RNA presence.Specific IgG and IgM antibodies to SARS-CoV-2 were detected in blood serum by enzyme-linked immunosorbent assay (ELISA) using test systems “ELISA anti-SARS-CoV-2 IgG” (FBUN SSC PMB, Obolensk, Russian Federation), “SARS-CoV-2-IgG-IFA-BEST” and “SARS-CoV-2-IgM-IFA-BEST” (Vector-Best, Novosibirsk, Russian Federation).Results. The results of a study of the humoral immunity of patients with asymptomatic and clinical forms of COVID-19 are presented. The data indicate the production of specific IgG in the blood serum of people in 2–3 weeks after SARSCov-2 infection and reaching its maximum level on the 20–21st day. The seroconversion rate was 94.9 %. It was shown that the geometric mean titer of antibodies in asymptomatic and mild forms of coronavirus infection did not differ statistically and amounted to 1:512 and 1:632, respectively. Higher titers of antibodies (1:1600) were detected in the moderate form.Conclusion. The research results can serve as a basis for studying the dynamics of changes in the indicators of the humoral immune response in patients with COVID-19 and for clarifying the duration of their post- infectious immunity in order to predict the development of the epidemic situation and to ensure the planning of specific prevention.

Objective of the seroepidemiological study was to determine the level and structure of herd immunity to SARS-CoV-2 among the population of the Irkutsk Region during the period of an increase in the incidence of COVID-19.Materials and methods. The content of antibodies to SARS-CoV-2 was determined by ELISA applying a reagent panel “ELISA anti-SARS-Cov-2 IgG” produced by the State Scientific Center of Applied Microbiology and Biotechnology (Obolensk).Results and discussion. The investigation has revealed that the herd immunity of the total population of Irkutsk Region amounted to 5.8 %. The greatest share of seropositive persons was among the children aged 14–17 (13.8 %) and 1–6 (11.8 %). It has been established that the risk of infection increases by 3.1 times in case of contact with COVID-19 patients. After exposure to COVID-19, antibodies were produced in 56.5 % of the cases. The share of asymptomatic forms among seropositive residents of the Irkutsk Region reached 81.2 %. Consequently, during the chosen period of increased COVID-19 incidence among the population of Irkutsk Region low level of seroprevalence was formed. A significant proportion of asymptomatic forms of infection characterize high intensity of the latently developing epidemic process. The results obtained can be used when organizing preventive measures, including vaccination, and for forecasting morbidity rates.

Vaccination remains the only way to prevent tick-borne encephalitis (TBE). All TBE vaccines are based on strains of the Far Eastern and European subtypes of TBE virus. Currently, the Siberian subtype of the virus, which differs from the vaccine strains, accounts for 80–100% of the genetic population of TBE virus in most of Russia. The proportion of TBE vaccinated patients among those infected was different from year to year in Russia, e.g. 3.9% in 2012 and 1.5% in 2018, there were also some fatal cases registered among vaccinated patients. In this regard, evaluation of the effectiveness of vaccination against various genetic subtypes of TBE is a promising area of research. The purpose of this study was to summarise the results of studies investigating effectiveness of specific prevention of TBE as regards various genetic subtypes of the virus. The paper analyses data on the effectiveness of TBE vaccination in experimental settings and in real life. It was demonstrated that the use of vaccines for prevention of TBE is effective, provided the vaccination coverage is not less than 80%. The paper cites the data from a long-term study of the stability and protective activity of vaccine immunity against TBE virus strains isolated in highly endemic territories. It was established that TBE vaccines have high immunogenic activity and contribute to the production of stable protective antibodies against the strains of the three genetic subtypes of the virus. Protective efficacy of vaccination depends on the number of vaccinations received, the vaccination scheme, gender and age of those vaccinated. The paper concludes by saying that further studies are needed to assess TBE vaccine efficacy in order to improve vaccination tactics, to better understand causes of morbidity and mortality among vaccinated individuals.

Under the conditions of intensive poultry farming and high concentration of poultry in a limited area mycoplasmoses cause significant economic damage to commercial poultry farming. Of greatest interest are respiratory mycoplasmosis and infectious synovitis, the causative agents of which are Mycoplasma gallisepticum and Mycoplasma synoviae, respectively. Considering that both diseases are included in the OIE list of notifiable diseases, it is necessary to perform constant control for their spread. The paper presents an analysis of serological test results for antibodies to mycoplasmosis agents in 2019. Six respiratory mycoplasmosis positive samples – and 129 infectious synovitis positive samples were detected when testing 2,401 chicken serum samples by the enzyme-linked immunosorbent assay (ELISA). The results of monitoring tests of samples received from 31 poultry farms (nine RF Subjects) indicate a decrease in the number of Mycoplasma gallisepticuminfected stocks and stable Mycoplasma synoviae situation. The respiratory mycoplasmosis epidemic situation on indoor poultry farms might have improved due to obtaining the poultry for commercial parent stocks from mycoplasmosis-free sources, better sanitary and hygienic conditions, elimination of the disease provoking factors, and the use of the disease-specific means of prevention in the parent broiler stocks. The infectious synovitis situation remains tense despite the fact that the number of Мycoplasma synoviae-infected farms decreased in comparison with the monitoring results for 2015–2018. Most seropositive stocks were detected on the layer farms (50.0% – in 2019). It seems appropriate to increase the amount of tests to be performed and the number of farms covered by testing in 2020 to more fully present the disease spread situation in commercial poultry farming in Russia.

Abstract Background Cystic echinococcosis (CE) is a worldwide parasitic zoonosis caused by infection of the larval stage of tapeworm Echinococcus granulosus. In human CE, the parasites develop and form cysts in internal organs. The differentiated cysts can be classified into five types based on WHO-IWGE standard CE1-5 representing different developmental stages. Infection with E. granulosus triggers hosts’ humoral and cellular response, displaying elevated serum antibodies and Th1 and Th2 cytokines, which are presumed to be in association with the disease outcome. Identification of immunological markers for evaluation of disease progression has been a growing concern. However, the distinctive profile of cytokines and antibodies associated with the cyst progression has not been ascertained. Methods To better understand the interaction between host immune response and disease outcome, the present study followed-up four CE patients over three years by yearly measuring serum level of 27 cytokines, total IgG and isotypes, and ultrasound scanning, beginning in year 1 for all patients with CE1 and CE2 cysts before treatment and continued in year 2 with CE4 and in year 3 with CE3-CE5 post-treatment. Results Nine cytokines including Th1-type IL-2, Th17-type IL-17A, and inflammatory cytokines IL-1β, IL-1Rα and TNF-α, chemokines IL-8, MIP-1α, MIP-1β, and growth factor G-CSF were significantly elevated in patients with cyst type CE1, compared to the normal controls, and then declined to a normal level at CE4 and CE5. Examining the antibody production, we found that serum specific IgG was significantly increased in patients with active and transitional cysts, specifically the total IgG at CE1/CE3/CE4-CE5, IgG4 at CE1 and IgG1 at CE1/CE3 cyst status, in comparison with the normal controls, but showed no significant changes between the cyst stages. Conclusions Our findings provide new information on the profile of multiplex cytokines and serum antibodies associated with cyst stages in cystic echinococcosis patients through a three-year follow-up, implying that further studies using an approach combining cyst-associated immune parameters may aid in identifying immunological markers for differentiation of disease progression.

Ixodes tick-borne borreliosis is a natural focal transmissive infectious multi-system disease featured with complex pathogenesis, which multiple aspects remain unclarified. The persistence stage during this infection associated with prolonged Borrelia presence in metastatic foci and repeated multiple dissemination is most complicated for clinical practice. It is assumed that the chronic process can be caused by an inadequate immune response associated with activated autoimmune mechanisms leading to emergence of permanent irreversible (degenerative and atrophic) changes in affected organs. Patients who experienced tick-borne borreliosis need dynamic observation for assessing disease prognosis providing a maintenance therapy. The purpose of the study was to evaluate an opportunity of using cellular immunity indices for predicting disease transition to a chronic course.Materials and methods. The study was carried out at the Medical Association of the Far East Branch of the Russian Academy of Sciences. Case report form data, serum and blood plasma samples collected from 22 patients aged 29–83 years old were examined. Immunological examination data from patients with ixodes tick-borne borreliosis (12–18 months after the onset of acute period) were analyzed. Specific IgM and IgG against Borrelia burgdorferi were determined by using the OMNICS diagnostic test system (St. Petersburg). Lymphocyte immunophenotyping was performed on BD FACSCalibur flow cytometer (Becton Dickinson, USA) by using doublelabeled monoclonal antibodies (Beckman Coulter, France).Results. A variability of activated peripheral blood lymphocytes was found in patients with tick-borne borreliosis evidencing about individual immune response. An imbalanced cellular immune response recorded in seronegative convalescents from tick-borne borreliosis, may be an indirect finding of ongoing Borrelia infection. Finding of specific serum IgG and IgM antibodies in convalescents at late stage coupled to impaired immune system is a warning sign presuming a risk to developing autoimmune reactions. Detection of specific IgM antibodies at late timepoint combined with increased immune cytotoxic potential may be referred to a marker of possible disease transition to chronic course.

The Ebola virus (member of Ebolavirus genus Filoviridae family) is the etiologic agent of extremely hazard human disease with high mortality rates (up to 90%). The most important components of spectrum of therapeutics for special prophylactic and current of disease, caused by Ebola virus, are prepares, based on virus specific antibodies (convalescent’s plasma, geterologic immunoglobulins, monoclonal antibodies. The use of different class therapeutics, based on virus specific antibodies, the possible improvements of its composition and strategy of its application for special prophylactic and current of disease, caused by Ebola virus, are considered in this review.

Aim. To study the level of specific antibodies of different isotypes to the antigens of Staphylococcus aureus and Klebsiella рneumoniae in the serum, saliva and nazal secret and the concentration of IgA,sIgA,IgG in saliva from frequently and long-term ill children in nasal-oral administration of Immunovac VP-4. Materials and methods. Specific antibodies to S. aureus and K.pneumoniae, contained in saliva, nasal, and serum were determined by the method of enzyme immunoassay. Concentrations of immunoglobulins of classes G, A and sА in saliva were determined by radial immunodiffusion using a commercial kit produced by the NPC «Medical immunology». Results. The high level of specific antibodies contained in the serum and nasal secretions, the level of antibodies in saliva is negligible. The serum is dominated by IgG-isotype antibodies, saliva and nasal secret — antibodies of IgA-isotope. After the introduction of Immunovac VP-4 there was a statistically significant increase in the level of specific antibacterial antibodies in serum, saliva and nasal secret, and increasing levels of IgG and sIgA in saliva. Conclusion. Obtained data demonstratet that the nasal-oral scheme of administration of Immunovac VP-4 frequently and long-term ill children allowed to increase the level of specific antibodies in serum, saliva and nasal secret to bacterial antigens that are part of the vaccine and to normalize the local synthesis of IgG and sIgA, which play a major role in the protection of the respiratory tract and mucous membranes of the upper respiratory tract.

Tularemia is an anthropozoonotic infection caused by Francisella tularensis. In clinical and sanitary-epidemiological practice, traditional diagnostics methods in tularemia are based on serological assays for detecting specific antibodies, allowing to diagnose it and estimate durability of patients’ immunity after vaccination. Previously, it was shown that specific serum antibodies in patients recovered after tularemia, unlike to those vaccinated with the live tularemia vaccine F. tularensis 15 NIIEG, can interact with specific epitopes on lipopolysaccharides isolated from strains of various subspecies — F. tularensis (Ft) and F. novicida (LPS Fn), while LPS Fn-specific immunoglobulins are lacked in the blood of vaccinated individuals. A set of experiments on identifying antibodies with similar specificity in laboratory animals of various species — mice, guinea pigs and rats with differed sensitivity to tularemia, administered with live tularemia vaccine strain as well as virulent F. tularensis strains to simulate vaccine-mediated and infectious processes, respectively was conducted. A methodical approach has been developed that allows to analyze humoral response in modelled infectious process in animals highly sensitive to tularemia such as BALB/c mice and guinea pigs that consisted of preliminary immunization with live tularemia vaccine followed by infection with virulent F. tularensis strains. It was shown that induction of specific anti-LPS Ft antibodies occured in these animal species, both after vaccination and infection with virulent strains. It was noted that, unlike guinea pigs and rats, mice both during vaccination and infection were characterized by significantly lower titers of LPS Ft-specific antibodies. However, no specific interaction between mouse serum and LPS Fn might be detected. Moreover, two types of immunoglobulins with different antigen specificities to the LPS Ft and LPS Fn epitopes were detected by dot-blot analysis in guinea pigs immunized with live tularemia vaccine, followed by infection with a virulent strain. In addition, antibodies to LPS Fn were also detected in the serum of rats infected with virulent, but not vaccine-based, F. tularensis strains. Thus, previous experimental data on the production of immunoglobulins with different antigenic specificity were confirmed in an experimental tularemia modelled in rats and guinea pigs that demonstrated a diagnostic significance and feasibility of using LPS Fn to confirm tularemia infection in humans.

The studies in the organism adaptation for the conditions of technogenic environmental changes, especially in child population, will allow to design a set of diagnostic markers for assessing the health status and early detection of pathological trends for development of hypersensitivity to environmental substances and improve efficiency of therapeutic and preventive measures. Metals are capable to alter functional activity of immune system by producing both immunostimulating and suppressive effects on immune reactivity, dependent on the properties of the given metal, its environmental concentration, source and duration of exposure. The aim of the present study was to investigate the features of hypersensitivity markers in children under the conditions of external exposure to aluminum. We have conducted a survey of the schoolchildren aged from 7 to 11 y.o. (a mean of 8.82±0.11 years), permanently inhabiting the territory of active industrial exposure associated with environmental contamination with aluminum compounds. The comparison group consisted of children from a “conventionally clean” area, with acceptable parameters of environmental quality. Specific features of sensitization developing to aluminum were evaluated, including both reactive and alternative mediator mechanisms (leukotrienes and prostaglandins), as well as participation of the cytokines in evolving sensitivity to the metal in the ex vivo experiments. We have shown a 1.43-fold increased level of metal in peripheral blood of the observation group, than in comparison group (respectively, observation group, 0.020±0.005 μg/ml; comparison group 0.014±0.003 μg/ml). Enhanced levels of IgE antibodies were found to be 2.13-fold higher compared to the reference values (213.55±88.10 IU/ml against normal rates of < 100.0 IU/ml) accompanied by increased specific IgG antibodies to aluminum (1.55-fold relative to the controls, i.e., 0.157±0.054 cu in observation group versus 0.101±0.041 cu for the comparison group), as well as a 2.09-fold increased spontaneous production of leukotrienes C4/D4/E4 (80.60±19.44 pg/ml for observation group; 38.51±2.40 pg/ml in the comparison group), which was 1.67-fold enhanced by experimental aluminum stimulation. Prostaglandin F2α levels among the children from observation group were increased 1.9-fold (observation group, 892.62±97.20 pg/ml; comparison group, 457.11±132.99 pg/ml, p < 0.05). Under the ex vivo experimental conditions, we observed mostly suppressive effects of aluminum upon the cytokine production. E.g., IL-4 production was inhibited by 2.13-fold, as compared with control values (observation group, 0.64±0.23 pg/ml; comparison group, 1.36±0.09 pg/ml); the suppression for IL-17 was 1.90 times (observation group, 1.08±0.27 pg/ ml; comparison group, 2.05±0.37 pg/ml, p < 0.05). The parameters studied may be used as aluminum hypersensitivity markers and used for monitoring and predictions in public health care.

The Coronavirus Disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has now become a global pandemic due to its high transmissibility. The unavoidable shortcomings of traditional diagnostic assay, including nucleic acid testing, diverse serological assays characterized by high-throughput and less workload, are playing a more and more crucial role to supplement the nucleic acid test. In this review, we summarize the dynamic change of the specific IgM, IgG, and IgA antibodies against SARS-CoV-2 as well as neutralizing antibodies and discuss the clinical utility and limitations of the different serological assays. SARS-CoV-2, a newly discovered virus, shows some unique pathogenetic and epidemiological characteristics that have not been completely understood so far. Currently, studies about the antibody responses against SARS-CoV-2 and the clinical utility of serological testing are increasing. It’s well suggested that the combination of serological tests and nucleic acid tests can cohesively improve the testing efficiency for identifying COVID-19 suspected patients.

The Coronavirus Disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has now become a global pandemic due to its high transmissibility. The unavoidable shortcomings of traditional diagnostic assay, including nucleic acid testing, diverse serological assays characterized by high-throughput and less workload, are playing a more and more crucial role to supplement the nucleic acid test. In this review, we summarize the dynamic change of the specific IgM, IgG, and IgA antibodies against SARS-CoV-2 as well as neutralizing antibodies and discuss the clinical utility and limitations of the different serological assays. SARS-CoV-2, a newly discovered virus, shows some unique pathogenetic and epidemiological characteristics that have not been completely understood so far. Currently, studies about the antibody responses against SARS-CoV-2 and the clinical utility of serological testing are increasing. It's well suggested that the combination of serological tests and nucleic acid tests can cohesively improve the testing efficiency for identifying COVID-19 suspected patients. [ABSTRACT FROM AUTHOR]

In the wake of the reproducibility crisis and numerous discussions on how commercially available antibodies as research tool contribute to it, The Antibody Society developed a series of 10 webinars to address the issues involved. The webinars were delivered by speakers with both academic and commercial backgrounds. This report highlights the problems, and offers solutions to help the scientific community appropriately identify the right antibodies and to validate them for their research and development projects. Despite the various solutions proposed here, they must be applied on a case-by-case basis. Each antibody must be verified based on the content of the product sheet, and subsequently through experimentation to confirm integrity, specificity and selectivity. Verification needs to focus on the precise application and tissue/cell type for which the antibody will be used, and all verification data must be reported openly. The various approaches discussed here all have caveats, so a combination of solutions must be considered.

Fasciola hepatica is the causative agent of fasciolosis, a significant parasitic disease occurring worldwide. Despite ongoing efforts, there is still no vaccine to control liver fluke infections in livestock. Recently, it has been suggested that natural antibodies (NAbs) can amplify specific antibodies (SpAb) and have a direct killing effect, but it is unknown if this phenomenon occurs during parasitic helminth infection or targeted vaccination. NAbs are antibodies produced by the innate immune system, capable of binding antigens without prior exposure. This study explores the role of bovine NAbs, using the exogenous glycoprotein keyhole limpet hemocyanin (KLH), in response to F. hepatica infection and SpAb production after infection and vaccination. The cattle’s NAbs were differently influenced by parasite infection and vaccination, with an increase in KLH-binding IgG and IgM levels after infection and reduced KLH-binding IgM levels following vaccination. Underlying NAbs reacting to KLH showed no correlations to the final fluke burdens after experimental infection or vaccination. However, NAbs reacting to whole-worm extract (WWE) prior to infection were positively correlated to increased fluke burdens within the infected bovine host. Furthermore, after infection, the specific IgG reacting to WWE was positively reflected by the underlying NAb IgG response. Following subcutaneous vaccination with F. hepatica native glutathione S-transferase (GST), there was a non-significant 33% reduction in fluke burden. Vaccinated animals with higher underlying NAbs had a higher induction of vaccine-induced SpAbs, with trends observed between KLH-binding IgM and anti-GST IgG and IgM. Our findings provide a platform to allow further investigation to determine if NAb levels could mirror fluke-SpAb production for exploitation in a combined selective breeding and vaccination program. Additionally, this work suggests that liver fluke could possibly evade the host’s immune system by utilising surface-bound IgM NAbs.

Detection of the measles virus (MV) specific IgM antibodies in blood serum of patients is considered to be the main standard for the laboratory confirmation of measles diagnosis, the test being acknowledged by WHO. As it was demonstrated earlier the specific IgM antibodies as the marker of the acute MV infection were detected in 97.2–100% of blood serum samples from patients using the ELISA test-systems of the “capture” format (Microimmun Ltd. and Vector Best). In case when the ELISA test-system of the “indirect” format (Siemens, Germany) was used only 63.9% of these sera turned to be IgM positive. And on the contrary using the “indirect” format ELISA test-system Euroimmun, Germany, for detection of the MV specific IgM the false positive results were obtained.The aim of the study was the comparative evaluation of the different format ELISA test-systems used for the detection of the MV specific IgM antibodies in blood sera of patients and healthy adults collected in different geographic zones.Materials and methods. In total 108 serum specimens collected in 2015–2017 were studied: from healthy adult Guineans, residents of the Republic of Guinea (RG); patients aged 1–70 with the initial “infectious mononucleosis”, “infectious cytomegalovirus” and “rubella” diagnosis and taken from the bank of sera in the Subnational Measles/Rubella laboratory, StP Measles/Rubella RC in NWFR. The MV specific IgM antibodies were detected using the commercial ELISA test-systems “VectoMeasles-IgM” (Vector-Best, Russia) (“capture” format) and “Anti-Measles Virus ELISA IgM (NP)” (Euroimmun Medizinische Labordiagnostik AG, Germany) («indirect» format). The specific Epshtein-Barr Virus (EBV) IgM and IgG antibodies were detected with the commercial ELISA test-systems «DS-ELISA-anti-EBV-VCA-M», «DS-ELISA-anti-EBV-EA-G» and «DS-ELISA-anti-EBV-NA-G» (“Diagnostic Systems”, Russia).Results and discussion. The MV specific IgM antibodies were not revealed in the total of 108 blood serum samples from the healthy adults and patients, residents of the Russia and of the RG, with the “capture” format “VectoMeasles-IgM” ELISA test-system. The absence of the acute MV infection was also confirmed by the high measles immunity level (i.e. IgG MV antibodies titers) as well as by detection of the IgG antibodies of high avidity. At the same time in 6 of 108 total sera (5.5%) IgM MV antibodies were detected with the «indirect» format ELISA test system Euroimmun, Germany. In these 6 sera the EBV specific antibodies were also evidenced. The results obtained demonstrate the nonspecific reaction due to the possible reactivity with anti-EBV antibodies. Besides this the different percentage of the false positive reactions in sera from healthy adults, residents of the RG and residents of Russia was determined — 8.5±4.0% and 3.2±2.2% correspondently. Thus the preliminary results, and to get the final results for general conclusions increase of the total amount of the clinical specimens under studying is of extremely importance.

Latex-agglutination preparations were produced for detection of antibodies to infectious hematopoietic necrosis virus of salmon with analytical sensitivity of 0,9 цд/ті. While testing 40 blood samples using latex-agglutination test the diagnostic sensitivity and specificity were 92 and 100%, respectively. The latex-agglutination is a simple and rapid test; it can be used for retrospective diagnostics of the disease and determination of the titer of antibodies to the virus under conditions of a veterinary laboratory and even a fish farm.

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Background: Cystic echinococcosis (CE) is a worldwide parasitic zoonosis caused by infection of the larval stage of tapeworm Echinococcus granulosus. In human CE, the parasites develop and form cysts in internal organs. The differentiated cysts can be classified into five types based on WHO-IWGE standard CE1-5 representing different developmental stages. Infection with E. granulosus triggers hosts’ humoral and cellular response, displaying elevated serum antibodies and Th1 and Th2 cytokines, which are presumed to be in association with the disease outcome. Identification of immunological markers for evaluation of disease progression has been a growing concern. However, the distinctive profile of cytokines and antibodies associated with the cyst progression has not been ascertained. Methods: To better understand the interaction between host immune response and disease outcome, the present study followed-up four CE patients over three years by yearly measuring serum level of 27 cytokines, total IgG and isotypes, and ultrasound scanning, beginning in year 1 for all patients with CE1 and CE2 cysts before treatment and continued in year 2 with CE4 and in year 3 with CE3-CE5 post-treatment. Results: Nine cytokines including Th1-type IL-2, Th17-type IL-17A, and inflammatory cytokines IL-1β, IL-1Rα and TNF-α, chemokines IL-8, MIP-1α, MIP-1β, and growth factor G-CSF were significantly elevated in patients with cyst type CE1, compared to the normal controls, and then declined to a normal level at CE4 and CE5. Examining the antibody production, we found that serum specific IgG was significantly increased in patients with active and transitional cysts, specifically the total IgG at CE1/CE3/CE4-CE5, IgG4 at CE1 and IgG1 at CE1/CE3 cyst status, in comparison with the normal controls, but showed no significant changes between the cyst stages. Conclusions: Our findings provide new information on the profile of multiplex cytokines and serum antibodies associated with cyst stages in cystic echinococcosis patients through a three-year follow-up, implying that further studies using an approach combining cyst-associated immune parameters may aid in identifying immunological markers for differentiation of disease progression. [ABSTRACT FROM AUTHOR]

The data on studying immunogenic activity of the inactivated vaccine produced on the basis of avian adenovirus isolate FAdV-2 are demonstrated in the paper. The dynamics of antibody accumulation in chicken blood is shown. The high resistance of immunized chicks to homologous virus (FAdV-2) infection and lack of protection against heterologous virus (FAdV-4) infection are also demonstrated.

The purpose of this study is to describe both clinical and immunological features in large cohort of adult patients with IgG subclass deficiency, and response to immunoglobulin therapy. This is a retrospective study of data obtained from electronic medical records and paper charts of 78 patients with IgG subclass deficiency seen and followed at our immunology clinics from 2010 to 2016. Both isolated selective IgG subclass deficiency as well as combined (two) subclass deficiencies were observed. IgG3 subclass deficiency, isolated and in combination with other IgG subclass deficiency, is the most frequent of IgG subclass deficiency. A majority of patients presented with upper and lower respiratory tract infections, especially chronic sinusitis. Both allergic and autoimmune manifestations are common; however, there is no subclass preference. The proportions and absolute numbers of CD3+ T cells, CD4+ T and CD8+ T cells, CD19+ B cells, and CD3−CD16+CD56+ NK cells were normal in the majority of patients in all IgG subclass deficiencies. Total serum IgG levels did not correlate with IgG subclass levels across all IgG subclass deficiencies. Anti-pneumococcal polysaccharide antibody responses were impaired in 56% of patients. IgG3 subclass deficiency is the most common IgG subclass deficiency, and anti-polysaccharide antibody responses are distributed among IgG subclasses with modest preference in IgG2 subclass. The majority of patients treated with immunoglobulin responded by reduction in frequency of infections and requirement of antibiotics. [ABSTRACT FROM AUTHOR]

Highlights • Responses to vaccination were examined in salmon head kidney during five weeks. • Transcriptome analyses showed shift in character of inflammation after two weeks. • This coincided with B cells differentiation and increase of nonspecific antibodies. • Antibodies to bacterial antigens delivered with vaccine appeared one week later. • Antibodies responses were mirrored with changes in repertoire of IgM transcripts. Abstract The majority of studies of vaccine responses in Atlantic salmon have focused on several weeks after vaccination, and employed a limited number of marker genes. In this study, novel techniques were used to examine a broad panel of expressed genes and antibody repertoire of Atlantic salmon following vaccination. Salmon parr were vaccinated with a multivalent oil-based vaccine, and blood plasma and head kidney were sampled at several time-points between 0–35 days post vaccination. Saline-injected fish were used as control at all time-points. Microarray analyses showed increased expression of immune genes from the first day to the end of study in the head kidney of vaccinated fish. Genes up-regulated in the late phase included several leukocyte markers and components of the oxidative burst complex. A suite of genes that can take part in B cells differentiation were up-regulated from day 14, at which time secretory IgM transcripts also peaked. This coincided with marked increased plasma titres of non-vaccine specific antibodies binding to a hapten-carrier antigen DNP-KLH, while antibodies to bacterial components of the vaccine, Moritella viscosa and Aeromonas salmonicida, first showed significantly elevated antibody levels at day 21, and at a markedly lower magnitude than the non-vaccine specific titres. Sequencing of the variable region of IgM heavy chain (CDR3) revealed higher cumulative frequencies of unique clonotypes in vaccinated salmon starting from day 14 when specific antibodies were first detected. Reduced sequence variance of CDR3 suggested expansion of recently emerged clonotypes. Overall, the results presented here follow a broad panel of gene expression, immunoglobulin sequencing and plasma antibody titres in the first few weeks after vaccination of Atlantic salmon, pointing to a potentially important contribution of non-vaccine specific antibody responses early in the vaccine response. [ABSTRACT FROM AUTHOR]

Abstract A new immunoassay format using thermally induced defragmentation of some nitro-explosives with a high degree of selectivity is reported. Specific antibodies against three widely used explosives, 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), and pentaerythritol tetranitrate (PETN) were generated by designing suitable haptens using geometry optimization modules. These in-house generated antibodies were used in a newly developed thermal mediated immunochemical biosensing technique which involves the binding of specific antibodies to respective nitro-explosives on a microtiter strip, resulting in the formation of specific immunocomplex. Heating the specific immuno-complex formed on microtiter wells resulted in thermal lysis of nitro-explosives to generate nitrite ions. These ions react with Griess reagent to form a colored chromophore which correlates the concentration of individual explosive in the sample. The present work fulfills the need for an improved explosive detecting system that is highly specific and capable of quickly determining the presence of nitrate containing explosives from a mixture pool. Highlights • A new immunochemical sensing strategy based on thermally induced lysis of nitro-explosives is demonstrated. • Thermolysis of nitro groups from respective explosive-antibodies immunocomplex are monitored by a nitrite specific reagent. • Optically determined color signal correlate the concentration of individual explosive from the pool of sample mixture. • The analytical ability of developed direct immunoassay for PETN, RDX, and TNT detection up to sub-ppm range is demonstrated. • The work fulfil the current need for detecting nitrate containing explosives with high degree of selectivity and accuracy. [ABSTRACT FROM AUTHOR]

Background: Epstein-Barr (EBV) and cytomegaloviral (CMV) infections are among most prevalent in the population worldwide that are associated with autoimmune processes. However, conflicting data of the studies on the role of herpes viral infections in the etiology of autoimmune pemphigus does not allow for reliable recognition of these viruses as triggers in the development and course of this bullous dermatosis. Aim: To assess specific IgM and IgG antibodies to herpes virus infections in patients with autoimmune pemphigus. Materials and methods: Serum samples from 15 patients with autoimmune pemphigus were analyzed by chemoluminescent immunoassay. Results: In the serum samples of 14/15 (93.3%) patients with autoimmune pemphigus we found specific IgG antibodies to nuclear and capsid EBV proteins at the levels of 30.7 to 600 U/mL (median, 147.5 [102.62; 313.25] U/mL) and from 33.5 to 567 U/mL (median, 186 [85.95; 492.5] U/mL), respectively. Specific IgG antibodies to the EBV early protein were found only in 6.7% of cases. In all patients, there were no specific IgM antibodies to EBV capsule antigens. All patients (100%) had specific IgG anti-CMV antibodies in the range from 64.5 to 138 U/mL (median, 103.5 [94.83; 113.75] U/mL). In 30% of cases, there were specific IgM anti-CMV antibodies at titers of 11 to 12.3 U/mL (median, 5 [5; 9.5] U/mL). Conclusion: The results of the preliminary study showed that 93.3% of autoimmune pemphigus cases have an underlying chronic infection caused by EBV and CMV. The finding of the high titers of IgG anti-EBV and anti-CMV antibodies allows to conclude that the association of these viruses with the bullous dermatosis is not just a chance. It makes further research undoubtedly necessary. Its results would draw more accurate conclusions on the role of EBV and CMV in the pathogenesis of autoimmune pemphigus and to find new perspectives in the treatment of patients with this life-threatening disease.

A problem of similarity and differences between so-called polyreactive immunoglobulins (PRIGs) and natural antibodies (NAbs), capable of cross-reacting with some structurally dissimilar antigens, has been considered. The analysis of mechanisms of an unspecific interaction between PRIGs or NAbs and antigens evidences for the fact that essential differences exist between these substances. These differences permit classifying the abovementioned substances as different types of immunoglobulin molecules. The major difference between PRIGs and NAbs may include both the mechanisms of the above mentioned immunoglobulin molecules binding to antigens and their interaction affinity, as well as an absolutely different influence of some low-molecular substances on the efficiency of the interaction with antigens. Relying on the obtained data it can be assumed that, since PRIGs and NAbs have fundamental differences, they may perform not only similar but also different functions of the immune system.

Abstract. Twenty healthy children were vaccinated, and then in a 5 years they were revaccinated with Priorix (measles, mumps, rubella vaccine), according to the national immunization calendar. The aim of the study was to observe and compare the shaping and maintenance of immunological memory. Specific IgM, IgA, IgG antibodies in serum, and their subclasses as well as antibodies avidity were tested by ELISA. It was demonstrated that IgM, IgG, and IgA antibodies shaped primary immune response to Priorix. Booster-effect was found in IgG and IgA antibodies in response to revaccination. Low avidity of antibodies in primary immune response changed to the high avidity (60–70%) antibodies of memory response to measles and rubella, and remained low for antimumps antibodies. IgG3 subclass was predominant, and IgG1 and IgG4 subclasses were involved in primary immune response. At the stage of immunological memory IgG1 was predominanted and IgG3 and IgG4 became minor.