M and M-like proteins represent the main pathogenicity factors of Streptococcus pyogenes, a widely spread and potentially lethal bacterial pathogen. These proteins provide resistance of the microbe to innate and adaptive immune response, due to attraction of specific human proteins to the streptococcal surface. Nonimmune binding of immunoglobulins G (IgG) and A (IgA) via their Fc domains to M and M-like proteins was described over 40 years ago, but its role for the pathogenicity of Streptococcus pyogenes is far from definite resolution. The discovery of this phenomenon should be considered among quite significant achievements of modern microbiology, since it had a huge impact upon development of innovative approaches, technologies and tools for microbiological, immunological and molecular diagnostics. It also promoted fundamental studies in pathogenesis of distinct infectious states and their complications caused by S. pyogenes. The non-immune binding of host immunoglobulins was previously suggested to be important mainly in immune conditions on the surface of mucous membranes and their secretions, but not in blood plasma, whereas other studies have pointed to significance of this phenomenon in protecting microbes from phagocytosis in non-immune blood of the host. It was also shown that the effect of Fc-binding causes increased pathogenicity of streptococci both in primary focus of infection, and during chronical course of the process, thus contributing to development of autoimmune diseases caused by S. pyogenes infection and leading to tissue damage in experimental animals. The experimental autoimmune process can be prevented by administering purified Fc fragments of immunoglobulins to the animals, blocking this process at the early stages of its development. A significant place in pathogenesis of IgA nephropathy (IgAN) belongs to streptococcal diseases. IgAN has been described as a mesangial proliferative process, due to initial IgA-Fcα deposition in renal mesangium cells. The data from literature describe successful modeling of individual IgAN traits, and expand our understanding of pathogenic properties and functions of Fcα binding receptor M proteins of S. pyogenes. The data reviewed in the article also presume the relevance of recently proposed ideas about an important role of non-immune Ig binding in streptococcal diseases, even in cases that differ in their development mechanism. These studies, including possible search for tools and techniques of preventive and potentially therapeutic applications, require additional efforts to study the binding of Fc fragments of IgG and IgA to M and M-like proteins of Streptococcus pyogenes.

Permanently increased frequency of drug hypersensitivity is observed throughout the world and continues to be of concern to clinicians of either discipline. Diagnostic problems with prevention and treatment of hypersensitivity reactions are due to different pathogenetic mechanisms that may underly similar clinical manifestations. On the other hand, clinical symptoms, response to therapy and the outcome of the disease significantly depend on clinical state of the patient. The phenotypes which are determined by clinical manifestations, and endotypes dependent on the pathogenetic mechanisms of hypersensitivity reactions were specified to the purpose of personalized therapy. Two kinds of phenotypes are described: with immediate (1-6 hours) and delayed (more than 6 hours) onset of the response. Four types of hypersensitivity according to Gell and Coombs with the presence of primary sensitization are discerned between the endotypes. Moreover, interaction of drugs with immune receptors of lymphocytes, according to the Pichler’s pharmaco-immune concept, has been identified, along with quick impact of drugs directly upon receptors of effector cells and signaling cascades without primary sensitization, which was previously termed as “pseudo-allergy”. To optimize therapy and prevent repeated reactions in the patients with drug hypersensitivity, high-quality diagnostics with detection of the causal allergen is required. This strategy currently includes analysis of medical history, physical examination as well as in vivo and in vitro testing. Provocation tests are rarely used, due to the significant risk of severe adverse reactions. Skin tests are a reliable and cost-effective tool, if the case history infers possibility of IgE-dependent reactions. Among nonspecific laboratory markers, the greatest clinical value is shown for determining serum tryptase levels, especially in anaphylactic reactions. In addition to genetic testing, several specific laboratory methods are used, i.e., measuring levels of drug-specific IgE, assessment of antigen-induced activation and proliferation of lymphocytes as well as basophil activation test, which has a number of advantages and allows us to identify a causally significant allergen for the hypersensitivity reactions proceeding by various mechanisms. Due to dysregulation which is a key factor of allergic inflammation, the mechanisms of normalization for impaired immune regulation should be understood, thus offering new strategies for personalized treatment, e.c., modulating the regulatory cell functions, aiming for control of the drug hypersensitivity reactions.

Autoimmune diseases are highly prevalent in humans, being characterized by early onset and high risks of disability, thus determining the relevance of the present work and its aim, i.e., studying metabolic characteristics of lymphocytes upon the adjuvant-induced autoimmune disorder in rats. Modeling of the autoimmune process was performed in Wistar rats by subcutaneous administration of a Freund’s complete adjuvant, i.e., water-oil emulsion with heat-killed M. tuberculosis. Hematology testing (complete blood counts), biochemical markers (hydroperoxides, malondialdehyde (MDA), catalase), and cytobiochemical changes in lymphocytes (lactate dehydrogenase, succinate dehydrogenase; LDH, SDH) were followed in dynamics. X-ray examination was performed at the end of the experiment. At the initial stage of autoimmune arthritis (2 weeks), leukocytosis was registered (26.12±2.30 × 10⁹ /L, i.e., 65% over the controls, p < 0.01), thrombocytosis (675±30 × 10⁹ /L, compared with 536±27 × 10⁹ /L in controls, p < 0.01), and oxidative stress were also observed (hydroperoxides increased by 7%, and MDA, by 32%, p < 0.001); energy levels of the lymphocytes increased due to activation of LDH by 6.5%, and SDH, by 49% against the controls. At chronic stage of the disorder (7 weeks), the systemic inflammation was milder (total WBC counts of 19.6±1.40 × 10⁹ /L, compared with 13.68±0.86 × 109 /L in controls, p < 0.01, associated with shift to the right in differential conuts), along with persisting oxidative stress (MDA exceeds the control levels by 37%; decrease in catalase activity), and lower LDH activity in lymphocytes (by 43%, p < 0.01) associated by their decrease in size (the correlation quotient between the lymphocyte radius and LDH activity is r_xy = 0.87). Profound molecular changes were observed in the cell energy supply: the respiratory quotient for control animals (LDH/SDH ratio) varied within 4.6-5.0. Meanwhile, in autoimmune animals, metabolic contribution of glycolysis showed a significant decrease (the quotient of 3.2 by the 2^nd week, and 2.4 by the 7^th week). On the radiograph by 7^th week, the experimental animals show uneven joint space narrowing, cyst-like formations and subchondral sclerosis of the bone heads. Autoimmune rheumatoid arthritis in rats is characterized by metabolic disorders of lymphocytes manifesting as general energy deficiency, and imbalance between glycolysis and oxidative phosphorylation pathways. These findings allow of deeper insight into pathogenesis and suggesting further search for molecular targeted therapy and prevention of the disease.

To date, participation of biogenic polyamines has been studied in details, with respect to regulation of microbial gene expression, interrelations between bacteria, development of their persistence state. Opportunity of their use as markers of human pathological conditions is being actively evaluated. The aim of our study was to assess the effect of bacterial diamines, i.e., cadaverine and putrescine, upon production of key cytokines (IFNγ and IL-4) in the culture of human mononuclear leukocytes. We studied leukocytes of peripheral venous blood obtained from 18 healthy male volunteers (mean age 24.0±0.6 years). The leukocytes were isolated by means of gradient centrifugation using a Ficoll-Verografin mixture. For the cultivation of lymphocytes, a micro-method and plastic round-bottom 96-well plates were used. Concanavalin A at a concentration of 5 μg/ml was used as a T cell mitogen. Polyamines were used at final concentrations of 5, 25, 50, 75 and 100 μM/L. The cultivation was carried out in humidified atmosphere with 5% CO2, at 37 °C for 72 hours. At the end of incubation, the culture medium was collected and frozen for subsequent quantitative enzyme immunoassays of cytokine concentrations (IFNγ and IL-4) (Russia). Viable cells were counted using Goryaev chamber after staining with 0.1% trypan blue solution. Statistical analysis was performed using Student’s t test or Mann–Whitney test. Addition of cadaverine at all concentrations reduced IFNγ production in the culture of mitogen-activated cells. When culturing leukocytes supplied with putrescine (5 to 50 μM/L), a dose-dependent decrease of IFNγ was observed. Upon further increase of putrescine concentrations, the IFNγ production is restored to the values of the control samples. Direct toxic effect of polyamines upon the cells was revealed. Both the diamines, at the doses of 50, 75, and 100 μM/L, caused increase of IL-4 production by the mitogen-activated cells. Such changes can be associated both with direct cytotoxic effect of cadaverine and putrescine, being mediated by changes of some metabolic pathways. In addition, the effects of polyamines upon monocytes present in culture can include their anti-inflammatory state, e.c., an increased IL-4 production. In general, cadaverine and putrescine, produced by microorganisms of various taxonomic groups, regulate the effectiveness of compensatory-adaptive reactions that ensure adaptation of microbial populations to changing or unfavorable environmental conditions.

Diabetes mellitus is a metabolic disorder, which results from insufficient secretion of insulin and/or its action, thus leading to hyperglycemia. Liver damage is known to be among the most common complications of type 2 diabetes mellitus (T2D) and is common in T1D. Comparison of the leukocyte phenotypes in liver tissue with appropriate blood parameters may assess degree of liver damage and search for approaches to correction of liver destruction in diabetes mellitus. Therefore, we aimed for assessment of changes in liver injury markers in blood and the numbers of leucocytes (CD45⁺ cells), T lymphocytes (CD3⁺ cells) and macrophages in the liver in experimental models of types 1 and 2diabetes. The experiment was conducted on 30 male Wistar rats. Alloxan at the dose of 170 mg/kg of body weight was used for T1D modeling. To provide a model of T2D, streptozotocin and nicotinamide were injected at the doses of 65 mg/kg, and 110 mg/kg respectively. Intact animals were used as a comparison control. Biochemical, hematological, immunohistochemical and morphometrical methods were used in the study. In T1D and T2D groups, levels of glucose (10.88±0.47 mmol/l and 10.78±0.42 mmol/l) and glycosylated hemoglobin (6.73±0.78% and 6.60±0.20% correspondingly) were rather close to each other and exceeded the values of intact rats (5.20±0.40 mmol/l and 4.07±0.30%). At the same time, the increase in total leucocyte number and fraction of peripheral blood leucocytes against normal levels were more pronounced in the T2D group than in T2D group. In liver of rats from the both diabetic groups, increased numbers of sinusoidal cells, macrophages, CD45⁺ cells and CD3+ cells relative to intact rats were detected. However, in rats from T1D group, CD45⁺ cells were distributed, mainly, in the liver parenchyma, whereas in rats in T2D group they showed sinusoidal location. At a similar degree of increasing macrophage numbers, and total CD45⁺ cells number, higher counts of sinusoidal cells and CD3⁺ cells, located both in the parenchyma and perivascular area, were found in rats of T2DM group compared with this parameter in T1DM group. An increase in ALT activity confirms a more significant damage to liver cells in animals of the T2DM group, whereas, in T1DM group, an increased AST activity and a less pronounced increase in ALT activity indicate uniformly distributed cytolysis. The results of our study showed, that, despite similar hyperglycemia level, the inflammatory process at the level of the whole organism and local inflammatory process in the liver are more pronounced in the T2DM group. A more significant severity of inflammatory process and liver damage corresponds to increase in sinusoidal cells and CD3⁺ cell infiltration of liver tissue.

Impaired balance of T regulatory and T effector lymphocytes has recently been considered as an important pathogenetic link in arterial hypertension (AH). There are, however, contradictory literature data about contents of these cells in the patients with hypertension, or obtained in experimental animal models of induced hypertension. Most results about changed patterns of immune cells in cardiovascular diseases were obtained by means of flow cytometry. There are also some works on expression of genes encoding surface and cytoplasmic differentiation antigens of immune cells in the patients with cardiovascular pathologies. These results coincide with the data obtained with flow cytometric techniques. Purpose of the present study was to analyze of the levels of gene transcripts encoding differentiation markers of regulatory (FOXP3, IL2R) T cells, effector T subpopulations (T helpers 17 (RORγ), and CD8 lymphocytes (CD8A) in healthy subjects and the patients with arterial hypertension (stages I-II). We examined healthy individuals (40 people, 20 men and 20 women), 27 patients with hypertension who did not receive antihypertensive therapy (14 men and 13 women), 26 hypertensive patients taking β-adrenergic receptor blockers (metoprolol or bisoprolol), including 12 men and 14 women. The relative levels of transcripts in peripheral blood leukocytes were assessed by real-time RT-PCR. It was shown that the transcriptional activity of FOXP3, IL2R, RORγ, and CD8A genes in peripheral blood leukocytes of the diseased people was significantly higher than in healthy individuals (p < 0.01). This finding may indicate an increased number of circulating T regulatory lymphocytes, CD8+ cells and T helpers 17 in hypertensive patients, and activation of T cell immunity in these patients. There were no statistically significant gender differences in FOXP3, IL2R, RORγ and CD8A gene expression in leukocytes, both in the group of healthy people and in hypertensive patients. The patients receiving cardioselective β-adrenergic receptor blockers (metoprolol and bisoprolol) exhibited lower expression of these genes, thus, probably, indicating antiinflammatory and immunomodulatory properties of these drugs.

The last fifteen years have been marked by rapid progress in the study of neutrophils. The discovery of transcriptional plasticity of neutrophils, their phenotypic and functional heterogeneity contributed to launching active interdisciplinary studies on the role of neutrophils in various chronic inflammatory diseases. Increased systemic circulation of immunosuppressive neutrophils can be observed not only in sepsis, but also in chronic systemic inflammation, which, along with disorders of lipid metabolism, is the major mechanism of atherosclerosis development and progression. Monocytes, dendritic cells, Tlymphocytes and neutrophils are key participants and modulators of inflammation in atherosclerosis. Potential significance of immunosuppressive neutrophils in atherogenesis and regulation of inflammatory response in atherosclerosis has not been currently established. However, taking into account their possible effects upon T lymphocytes and innate immunity cells, the study of immunosuppressive neutrophils seems promising in the context of atherosclerosis and atherosclerotic cardiovascular diseases. The purpose of this study was to evaluate relationship between the numbers of circulating immunosuppressive neutrophils and subpopulations of T cells and monocytes in the patients with subclinical atherosclerosis. The study enrolled patients aged 40-64 years with subclinical atherosclerosis of peripheral arteries. Subpopulations of neutrophils, lymphocytes and monocytes were phenotyped by flow cytometry using “Navios 6/2” (Beckman Coulter). 133 patients, 65 (48.8%) males and 68 (51.2%) females were included into the study. Correlation analysis showed that increased number of circulating CD16^hiCD11b^loCD62L^br neutrophils was associated with increased number of regulatory T lymphocytes. The patients with subclinical atherosclerosis and absolute numbers of circulating immunosuppressive neutrophils within the first quartile (<136 cells/μL) had a statistically significantly lower number of regulatory T lymphocytes compared with patients in the 2-4 quartiles. An increase in immunosuppressive neutrophils was associated with decreased number of classical monocytes expressing TLR4 (r = -0.335; p = 0.004), and a decrease in TLR2 surface expression intensity (r = -0.268; p = 0.023) on the non-classical monocytes. In patients with subclinical atherosclerosis of 40-64 years old, an increase in immunosuppressive CD16^hiCD11b^loCD62L^br neutrophils was associated with increase in regulatory T lymphocytes and nonclassical monocytes, as well as decrease in classic monocytes expressing TLR4, and lower intensity of TLR2 expression on the non-classical monocytes.

Among the causes of visual impairment, cataract occupies a significant proportion, which indicates a need for studying the causes of its development. Over recent years, an important role has been given to impaired immunoregulatory reactions in its genesis. So far, however, participation of systemic cellular immunity in occurence of different clinical types of cataract remains poorly known. The aim of the present study was to assess association between parameters of systemic cellular immunity and development of mature nuclear cataract. On the basis of IRTC “S.N. Fedorov Eye Microsurgery Center” (Tambov Branch), a study of major immune cells subpopulations in peripheral blood was performed over 2019-2020 in 63 patients aged 60-84 years, suffering from mature nuclear cataract (the study group). The control group consisted of 47 patients aged 60 to 84 years without ocular disorders in the history and at the time of examination. The evaluation of differentiated cell clusters was carried out with BD FACS Canto II flow cytometer. As a result, a statistically significant decrease in the absolute number of CD19⁺ to 0.18±0.003 × 10⁹ /L was revealed in the patients from the main group versus 0.42±0.05 × 10⁹ /L in controls; the relative number of CD19⁺ was decreased to 8.36±1.1% versus 19.64±1.3%, respectively, along with absolute content of CD3⁺ cells of 0.92±0.08 × 10⁹ /L versus 1.57±0.06 × 10⁹ /L in controls. On the contrary, the absolute number of CD56⁺ in the patients with mature nuclear cataract was significantly increased to 0.27±0.02×10⁹ /L compared to 0.15±0.03 × 10⁹ /L in the age control group. The relative risk values are statistically significant, and the highest levels were found for CD19+ and CD3⁺ cell clusters, which were 3.237 and 2.954 for the absolute number, and 1.952 and 2.748, for the relative number, respectively. These findings suggest that development of a mature nuclear cataract is associated primarily with a decrease in absolute and relative contents of B and T lymphocytes at the systemic level, which may be of practical importance when used as immunological markers of nuclear cataract.

Primary open-angle glaucoma combined with dry eye syndrome is the leading cause of irreversible blindness. Complement system remains nearly unexplored in this disorder. The aim of our study was to evaluate the parameters of complement system in primary open-angle glaucoma and dry eye syndrome among elderly persons. The study was conducted at the S. Fedorov Center of Eye Microsurgery (Tambov Branch), and enrolled 62 patients aged 60 to 74 years with primary open-angle glaucoma combined with dry eye syndrome, and 33 patients free of this pathology. The blood complement system was studied by hemolytic method and enzyme immunoassay, and the C1 inhibitor was studied by chromogenic method. To assess possible contribution of the complement system components to the mentioned eye disorder, appropriate odds ratios were calculated, according to the generally accepted method. The study of blood complement system in elderly patients with combined primary open-angle glaucoma and dry eye syndrome have shown, first of all, high C3a level (up to 106.2±3.9 ng/ml), increased contents of C5a (4.5±0.2 ng/ml), and factor H (215.9±5.2 mcg/ml), along with decreased C1 inhibitor (to 168.4±6.1 mcg/ml). In the age-matched control group, the contents of appropriate plasma complement factors were, respectively, 45.2±4.0 ng/ml; 3.1±0.2 ng/ml; 141.5±4.3 mcg/ml; 237.9±5.8 mcg/ml, showing significant difference for all these parameters. An important pathogenetic role of C3a component, C5a component, factor H, and the C1 inhibitor in development of combined primary openangle glaucoma with dry eye syndrome was confirmed by the values of odds ratio (OR) with maximum value for the C3a component (OR 4.035, CI 3.640-4.283, p < 0.0001), which indicates increased risk of developing the mentioned ophthalmopathology in old age. High odd ratios were also characteristic of C5a blood components (2.946; CI 2.618-3.547), C3 (2.821; CI 2.453-3.264), factor H (2.765; CI 2.431-3.148). Less significant changes were revealed for other complement components thus suggesting only marginal association with development of primary open-angle glaucoma with dry eye syndrome in old age This indicates that the development of primary open-angle glaucoma with dry eye syndrome is associated with activation of these factors of the complement system. The revealed features of the complement system will enable us for more effective diagnostics of these combined eye disorders.

Immune disorders play an important role in development of age-related ophthalmic diseases (e.g., cataracts, age-related macular degeneration), as well as in geriatric conditions and, above all, in senile asthenia syndrome, the leading deficiency syndrome among people at their older age. However, the changes in systemic interleukins in patients with simultaneous presence of two age-associated conditions (cataract and senile asthenia syndrome) were only poorly studied. The aim of the present work was to evaluate the systemic interleukin profile in elderly patients affected by cataracts combined with senile asthenia syndrome of different severity. Patients and methods: The contents of interleukins in blood serum was analyzed in a clinical setting among patients aged 60 to 74 years for all the groups which manifested with isolated cataracts (n = 58), cataracts and senile preasthenia (n = 49), and cataracts and senile asthenia syndrome (n = 56). The diagnosis of senile asthenia syndrome was established in accordance with indexes of the phenotypic model by Fried L. et al., and cataracts, according to results of clinical ophthalmological examination. Determination of IL-1, IL-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-17 and IL-18 were performed by enzyme immunoassay followed by calculation of relative risk for each of the above interleukin, as generally accepted. Results: A statistically significant increase of IL-1, IL-1β, IL-6, IL-8, IL-13 levels, along with decrease in IL-4, IL-10 were shown in the patients presenting with combination of cataract and senile pre-asthenia, as compared with patients with only cataracts. Among the patients with cataracts and senile asthenia syndrome, the disorders were diagnosed for a large number of interleukins, with increased levels of IL-1, IL-1β, IL-6, IL-8, IL-9, IL-12, IL-13, IL-17, IL-18, and decreased concentrations of IL-4, IL-10, in comparison with cases of isolated cataract, or cataract combined with senile preasthenia. Significant values of relative risk were revealed for cataract and senile preasthenia, i.e., for IL-1 (1.27), IL-1β (1.20), IL-4 (1.21), IL-6 (1.19), IL-8 (1.93), IL-10 (2.15) and IL-13 (1.23), and, in cases of cataracts and senile asthenia syndrome, for IL-1 (1.45), IL-1β (1.31), IL-4 (1.38), IL-6 (1.57), IL-8 (2.86), IL-10 (2.39), IL-13 (1.39), IL-17 ( 1.27). The results obtained point to marked changes in the mentioned systemic interleukins among the patients aged 60 to 74 years, and more pronounced association of these changes with cataract combined with senile asthenia syndrome, than with cataract and senile preasthenia.

Successive development of immunological tolerance to cow’s milk proteins largely depends on the timeliness and validity of the elimination diet and is most difficult in IgE-mediated food allergy. From 2012 to 2017, when examining children aged 3 months to 10 years, we found some cases with high levels of specific IgE to beta-lactoglobulin that exceeded the levels of specific IgE to the whole cow’s milk allergen (the latter is often used as a screening allergen). The aim of this study was to assess the informativity of studying the levels of specific IgE to the whole cow’s milk allergens in blood serum of children at early, preschool and primary school age. We have also included gluten (gluten) and soy as possible components of early childhood nutrition into the list of allergens under study. The study involved 100 children aged 9 months to 12 years. Clinical selection criteria included presence of anamnestic data on exacerbation of atopic dermatitis, urticaria, exacerbation of rhinitis/asthma, diarrhea, constipation or abdominal pain in response to usage of cow’s milk and/or dairy products during the last 6 months. It is shown that extended study of specific IgE levels to whole cow’s milk allergen, its components, as well as to soy and gluten, increases the accuracy of laboratory diagnostics and differential diagnosis of IgEmediated form of food allergy to cow’s milk proteins, compared with determination of serum IgE to whole cow’s milk as a screening test. A detailed study of specific IgE to milk components allowed to confirm the presence of IgE-mediated form of allergy to cow’s milk in 7% of the examined children with signs of food allergy, but in absence of specific IgE to whole cow’s milk allergen. We have also shown that in 29% of cases, the level of specific IgE to milk components was higher than those to whole cow’s milk allergen. The results of this study may be of practical importance, since the form of food allergy, as well as intensity and dynamics of reduction of production of specific IgE, are accepted criteria to forecast development of tolerance to cow’s milk proteins. In addition, identification of specific allergen (including soy bean allergen) that causes the most intense production of specific IgE, may be importance for administration of a reasonable elimination diet. The most significant allergens for diagnosis and differential diagnostics of allergy to cow’s milk in children, in addition to the “whole cow’s milk, f2” preparation, are the following allergens: “whey, f236”, “beta-lactoglobulin, f77” and “soy, f14”.

Endometriosis is a chronic gynecological disease, which poses a serious problem in terms of diagnosis and treatment. Despite decades of research, there are no specific signs and symptoms and no blood tests to clinically confirm the diagnosis, which makes timely diagnosis and treatment difficult. Therefore, the search for new markers for early non-invasive diagnosis of the disease remains relevant. Various subcellular structures involved in intercellular communication, in particular, microvesicles, can be considered promising biological markers for external genital endometriosis. The aim of this work was to assess the composition of microvesicles derived from leukocytes in the peripheral blood of patients with stage I-II of external genital endometriosis and the possibility of their use as markers of non-invasive diagnosis of peritoneal forms of endometriosis. The study involved 97 women aged 26-40 with stage I-II of external genital endometriosis, whose diagnosis was established intraoperatively and confirmed histologically. Pain syndrome was noted in all patients of the main group, with infertility also detected in 73.2% of the patients. The control group consisted of 20 patients, whose average age was 25.5±1.1 years, who were examined in connection with male infertility factor before the in vitro fertilization, and in whom, on the basis of intraoperative examination, presented no gynecological diseases, and no pain syndrome. Before the surgical intervention, peripheral blood was taken from all patients to determine the content of microvesicles derived from leukocytes. To isolate microvesicles, we used the previously described by M.P. Gelderman and J. Simak method. It was found that patients with stage I-II of external genital endometriosis experience an increase in the number of CD14⁺, CD16⁺ and CD54⁺CD14⁺ microvesicles in the peripheral blood by 1.1, 1.38 and 1.55 times, respectively, as well as a decrease in the number of CD45⁺CD4⁺, CD3⁺CD4⁺, CD3⁺CD8⁺ microvesicles by 1.2, 4 and 1.5 times, respectively, compared with patients from the control group. Therefore, in patients with stage I-II of external genital endometriosis, an increase in the relative number of CD54⁺CD14⁺ microvesicles in the peripheral blood above 5.22% can serve as a marker for early non-invasive diagnosis of the disease with sensitivity of 80.5% and specificity of 71%.

At the present time, studying humoral immunity to the new coronavirus infection is among the most important tasks. The COVID-19 infection induces a protective pool of specific antibodies determining severity and duration of such immune protection after convalescence. The antibody testing is also necessary for assessing efficiency of anti-COVID vaccines in order to defeat the SARS-CoV-2 pandemic. Despite enormous interest of scientific community in this problem seen in the literature, there is still a lack for longitudinal observations of immunological status (more than 6 months) in the patients who have undergone COVID-19. The aim of this study is a long-term monitoring (9-14 months) of development and extinction of immune response to SARS-CoV-2 infection using quantitative assessment of IgA and IgG levels in peripheral blood of the patients who had COVID-19 in anamnesis. Monitoring of anti-SARS-CoV-2 levels over time has demonstrated significant individual variability, and made it possible to divide the study participants into three groups, according to characteristic features of humoral immunity after documented COVID-19. The study describes characteristic features of humoral immune response for each of these groups. The first group (30% of the study group) exhibited classical pattern of antibody response to viral infection. The second group (40% of study participants) presented with high plasma IgA levels, and their significant excess (about 2 times) over IgG levels throughout the observation period. The third group (30% of study participants), apparently comprised the subjects with increased humoral immunity to SARS-CoV-2 infection. Their plasma antibodies remain at high levels for at least 9-10 months after the onset of infection. The data obtained confirm the pattern of plasma IgA which is not quite typical to viral infections in dynamics after a sufficiently long time period after the disease in most study participants (2nd and 3rd groups; 70% of all volunteers who have recovered from COVID-19) and suggests an important role of this immunoglobulin against SARS-CoV-2 infection. The specific responses of anti-SARS-CoV-2 IgG are very similar to behavior of such antibodies in other viral infections including contacts with coronaviruses from earlier generations. Humoral immunity against SARS-CoV-2 may persist for more than 6 months, thus supporting an assumption that the naturally infected patients are able to resist re-infection for a long time.

COVID-19, a severe acute respiratory syndrome caused by SARS-CoV-2, may predispose to thrombotic events, especially when combined with antiphospholipid antibodies (aPL). However, there are limited data on prevalence and antigenic specificity of aPL in COVID-19. Complement activation is assumed to play an important role in pathogenesis of COVID-19-associated coagulopathy. During the SARS-CoV-2 pandemic, it is necessary to identify important biomarkers for predicting severe course of COVID-19 and risk of thrombotic complications. Our objective was to evaluate the aPL profile, quantitative content and activity of complement and its components in COVID-19 patients graded by severity in the course of time. IgM and IgG antibodies to cardiolipin (CL), phosphatidylserine (PS), β2-glycoprotein-I (β2-GP-I), prothrombin (PT), annexin V (An V), as well as C1q complement component, content of its C3 and C4 components and total complement activity were determined in blood serum using ELISA approach. 141 patients with COVID-19 were included in the study. Group 1 consisted of 39 patients with mild form, group 2 (65 patients) presented with moderate form, and group 3 included 37 patients with severe form of COVID-19. Blood samples were obtained on day 3-7 of the disease (1st point) and after 14-28 days (2nd point). The results were as follows: aPL were detected in 29.1% of the total COVID-19 cohort, frequency of aPL detection by the severity grade did not differ (33.3%, 24.6% and 32.4%). In 8.5% of the patients, aPL were detected only at the 1st time point; in 14.2%, only at the 2nd point; and in 6.4% of the cases, at the both time points. Antibodies to PT (16.3%) and An V (11.3%) were revealed more frequently. The detection frequency of antibodies to PT was significantly higher than antibodies to CL and PS (7.1%), β2-GP-I (7.8%). The prevalence of aPL in groups 1 and 3 did not differ. At the 1st point in group 3, increased levels of C4 (89.2%) and C3 (24.3%) in blood, and a decrease in complement activity (35.1%) were more often observed than in group 1. At the 2nd time point in group 3, a decrease in complement activity was often detected (59.5%). The C3 levels exceeding 720 μg/ml were found to predict a 2.6-fold increased risk of severe COVID-19, and this risk became 3.3 times higher at C4 levels of > 740 μg/ml. The antibodies to PT and An V are often detected in COVID-19 patients, along with low prevalence of antibodies to CL and β2-GP-I. These antibodies can be involved in pathogenesis of COVID-19-associated coagulopathy, being detectable at the late stage of the disease, and they may trigger APS in predisposed patients and reconvalescents. Although presence of aPL antibodies is not associated with COVID-19 severity, their persistence over the period of convalescence may be an additional risk factor for thromboembolic complications. The COVID-19 patients are characterized by activation of the complement system, which increases in severe cases, and manifests with increased or decreased levels of C3 complement component, increased levels of C4 component in blood, and a decreased total complement activity. Quantitative determination of C3 and C4 complement components over the period of COVID-19 progression is of prognostic value, with respect to severity of the disease.

The dominance of reliably immunized population is a fundamental factor in prevention of COVID-19 pandemia, with immune prophylaxis taking a dominant position. Due to lack of clear data on the intensity of specific immunity after a new coronavirus infection, consolidation of immunological memory by vaccination becomes the urgent task, in order to exclude the risk of re-involvement of previously ill patients into the epidemic process. Meanwhile, many questions related to vaccination of COVID-19 survivors do not get distinct answers. To study the features of immune response, using a vaccine based on SARS-CoV-2 peptide antigens (EpiVacCorona), we monitored 81 participants. The inclusion criteria were data confirming COVID-19 in the anamnesis (medical documentation), low levels or absence of antibodies to the SARS-CoV-2 nucleocapsid protein, and negative PCR tests for SARS-CoV-2. When assessing the data of post-vaccinal immunity checked 21 days after 1st dose of the vaccine, the patients were divided into 2 groups: those who did not respond, and those who developed the immune response. In order to identify possible reasons for different phenotypic patterns of humoral response to vaccination, a comparative analysis of B lymphocyte indexes was carried out in these groups. Absolute counts, subpopulation composition and activation potential of peripheral blood B lymphocytes were determined by flow cytofluorometry using appropriate labeled monoclonal antibodies purchased from Beсkman Coulter. Comparative analysis of B lymphocyte indexes on the day of first vaccination showed that the persons who did not respond to the vaccine had smaller counts of circulating B cells, i.e., both percentage and absolute cell numbers, than in comparison group, as well as changed ratio of B1-to-B2 subpopulations. After administration of the first vaccine dose (by day +21), in alternative variant of the antibody response to V1, the differences in the parameters of B cells were presented as a smaller percentage and absolute numbers of regulatory B lymphocytes in non-responding participants. Moreover, the contents of minor B cell subpopulations were decreased in the non-responding group than in the comparison group, thus affecting the values of the B1:B2 ratio. In general, the presented data demonstrate that the absence of secondary immune response to antigens of the SARS-CoV-2 peptide vaccine could be is associated with altered differentiation of B1 and B2 subpopulations, B regulatory lymphocytes, B memory cells.

Impaired immunoregulation and development of autoimmune response to antigens of own intestinal microbiota and inflammation-altered antigens of colonic cells represent the key links in pathogenesis of inflammatory bowel diseases. Multimodal biological effects of ozone presunme the usage of local and systemic ozone therapy in complex treatment of many inflammatory diseases of the gastrointestinal tract. The aim of our work was to study effects of intraperitoneal and rectal ozone therapy upon immune parameters of the lesion focus in oxazolone-induced ulcerative colitis in the course of time. The study was carried out on 64 adult male inbred Wistar rats weighing 240±20 g. Experimental ulcerative colitis was produced by oxazolone treatment (4-ethoxymethylene-2-phenyl-2-oxazolin-5-one) (SigmaAldrich, USA). The ozone-oxygen mixture was injected intraperitoneally or rectally at a concentration of 1.0-1.2 mg/l, once a day, in a volume of 10 ml, at the 6-day course. The results of experiments were recorded on the days +2, +4 and +6. The concentrations of IL-17 and IL-23 was determined in a homogenate of intestinal tissues (Bender Medsystems, Austria) using a Personal LAB analyzer; expression of CD4 and FoxP3 on intestinal lymphocytes was determined by immunohistochemistry technique (ElisaKit, China). The observed tissue damage of large intestine showed an increase from day 2 to day 6 of oxazolone-induced ulcerative colitis. The total number of lymphocytes significantly increased upon development of experimental colitis, with parallel decrease in the number of CD4+ lymphocytes and FoxP3-positive T lymphocytes. IL-17 and IL-23 concentrations in the tissues increased with the severity of inflammatory changes in the lesion focus. Intraperitoneal ozone administration was associated with significant reduction of lymphocyte contents in the damaged tissues on the 6th day, whereas the numbers of CD4+ and FoxP3 positive T lymphocytes normalized by the 6th day. The levels of IL-17 and IL-23 increased from day 2 to day 6, with a lower IL-23 values on day 6 as compared with non-treated animals. Rectal administration of ACS led to the normalization of FoxP3 cells on the 6th day to the values of intact animals. The levels of proinflammatory cytokines (IL-17 and IL-23) significantly decreased on the 6th day as compared to the group of animals without treatment, which could be due to anti-inflammatory properties of ozone.

Coronary artery disease (CAD) is widely considered a chronic inflammatory disorder, and dysfunction of epicardial adipose tissue could be an important source of the inflammation. Amino-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) is a known marker of cardiovascular disorders of cardiac origin. Recent studies show that inflammatory stimuli may influence its secretion. Our purpose was to evaluate NT-proBNP serum concentration in relation to immune cell ratios in epicardial adipose tissue (EAT), and cytokine levels in the patients with stable CAD. Patients with stable CAD and heart failure classified into classes II–III, according to the New York Heart Association (NYHA) scale, scheduled for the coronary artery bypass graft (CABG) surgery, were recruited into the study (n = 10; 59.5 (53.0-65.0) y. o.; 50% males). The EAT and subcutaneous adipose tissue (SAT) specimens were harvested in the course of CABG surgery. Immunostaining with anti-CD68, anti-CD45, antiIL-1β and anti-TNFα monoclonal antibodies was performed to evaluate cell composition by differential counts per ten fields (400 magnification). Fasting venous blood was obtained from patients before CABG. Blood was centrifuged at 1500g, aliquots were collected and stored frozen at -40 °С until final analysis. Concentrations of NT-proBNP, IL-1β, IL-6, IL-10, TNFα were determined in serum samples by enzyme-linked immunosorbent assay (ELISA). We have found increased production of IL-1β and TNFα cytokines in EAT compared to SAT. Concentrations of NT-proBNP exceeded 125 pg/ml in 4 patients, and correlations between the CD68⁺ macrophage counts in both EAT and SAT samples (r_s = 0.762; p = 0.010 and r_s = 0.835; p = 0.003, respectively). NT-proBNP levels showed positive relations with CD45⁺ leukocyte counts (r_s = 0.799; p = 0.006), and with IL-1β⁺ cell numbers (r_s = 0.705; p = 0.023) in EAT samples only. As for the serum biomarkers, NT-proBNP levels showed negative correlation with fasting glucose levels (r_s = -0.684; p = 0.029), and positive correlation with serum IL-6 concentrations (r_s = 0.891; p = 0.001). Increased serum concentrations of NT-proBNP in CAD patients correlate with accumulation of macrophages in EAT, which is associated with increased production of IL-1β in EAT and correlates with some metabolic parameters.

Recently, the studies of environmental effects upon public health of children become quite relevant [1, 12, 20]. Over last decades, there is a rapid increase in allergic diseases, including allergic rhinitis, among the child population. A large number of studies connect this increment in pediatric allergies with influence of environment, technogenic development and urbanization [4]. Allergic rhinitis (AR) is one of the most pressing problems in allergology and immunology [2], being among the most common chronic disorders in children [6, 21]. Thus, it was found that the pathogenesis of AR is a complex mechanism that is not limited to a purely allergic reaction and inflammation in the nasal region. It includes complex mechanisms of neurogenic inflammation under participation of the main neuropeptides and neurotransmitters, which are closely related to the individual condition of endocrine and immune systems, being largely determined by the state of mucous membranes of the nasal cavity and respiratory tract in general. The pathogenesis of AR is primarily influenced by the state of microvasculature of the mucous membrane, as well as dictinct qualitative and quantitative characteristics of microbiocenosis of the nasal cavity, nasopharynx and oropharynx, upper and lower respiratory tract. All these parameters are directly determined by neurovegetative mechanisms [5, 7, 9, 16]. An important place in the pathogenesis of the development of allergic diseases belongs to changes of the microcirculation system which is involved into all the clinical manifestations observed. The microcirculation disorders play an important initial triggering role in pathogenesis of allergic rhinitis. Likewise, the autonomic nervous system is responsible for setting links between the body, ambient and internal environment via regulation of metabolism, functioning of organs and tissues based on changes in this environment; it also provides integration of all organs into a single entity, acting as one of the main adaptive systems in human body [13]. Therefore, the autonomic nervous system regulates the body and homeostasis by unifying the separate pathogenetic links of disease progression and setting basis for structural and functional unity [3, 19]. This regulatory mechanism is implemented via nerves and reflexes by different neurohumoral factors. Their nature has been established under experimental conditions and is beyond doubt to date [8].

Currently, there are only scarce data on dynamics of biologically active substances in the lesions associated with atopic dermatitis. Persistence of microorganisms in atopic dermatitis is high on the skin surface. However, pathophysiological significance of ENA-78/CXCL5 for development of atopic dermatitis was not studied so far. The ENA-78/CXCL5 is known to be produced by endotheliocytes, keratinocytes, eosinophils, fibroblasts to activate neutrophil migration, especially under the influence of LPS-containing microorganisms. The aim of this study was to evaluate the dynamics of ENA-78/CXCL5 chemokine levels in blood serum and skin exudates in the patients with atopic dermatitis, as well as to determine pathophysiological role of the chemokine in pathogenesis of dermatosis. 80 patients with limited and widespread forms of atopic dermatitis and 15 volunteers were under observation. The dynamics of ENA-78/CXCL5 levels was studied in blood sera and skin exudates. Blood samples for the study were drawn at the time periods of exacerbation and remission. Skin exudates were taken from the patients during the exacerbation period using disposable insulin syringes and 20-G disposable needles. In healthy volunteers, the skin exudate was obtained by the “skin window” technique as described by V.V. Klimov and coauthors “A method for assessing minimal inflammatory activity of skin in atopic dermatitis in remission”. The cell analysis was conducted by flow cytofluorimetry using the LEGEND plex TM Human Proinflammatory Chemokine Panel (USA) according to the manufacturer’s protocol. Serum concentrations of chemokine ENA-78/CXCL5 in adolescents with atopic dermatitis, exceeded the range for healthy volunteers. During remission of dermatitis, the chemokine level did not reach the indices in the control group. In adults, the ENA-78/CXCL5 concentration, both at the onset of symptoms and upon their resolution, was below the control levels. Maximal concentrations of ENA-78/CXCL5 chemokine were detected in the skin exudates. As based on our data on the dynamics of ENA-78/CXCL5 chemokine levels, it could be assumed that this substance may represent a sufficient link in pathogenesis of atopic dermatitis, by causing migration of neutrophils and monocytes to the affected area. The ENA-78/CXCL5 chemokine may be a marker of microbial pathogenesis and cellular damage in atopic dermatitis.

Neutrophils characterized by high mobility and ability for quick and accurate reresponse upon homeostatic changes. These changes primarily occur at the inflammation site. The pathogen elimination depends on the phagocytic activity of neutrophils. The data from past decades have revisited the role of neutrophils and their involvement in changing the human cellular and humoral immunity. Neutrophils are not only effector cells, but also regulatory cells of both innate and adaptive immunity. Our purpose was to study phagocytic activity and parameters of oxygen-dependent metabolism of peripheral blood neutrophils in young children with recurrent respiratory infections. We examined 111 children aged 1-3 years with recurrent respiratory infections over the period of clinical remission. The control group consisted of 24 healthy children aged 1-3 years. Phagocytic activity of peripheral blood neutrophils was studied by the latex test. Luminol-dependent chemiluminescence of blood neutrophils was studied according to de Sole et al. (1983). The study of phagocytic indexes of peripheral blood neutrophils in the children with recurrent respiratory infections has revealed a decrease in the number of actively phagocytizing cells and preservation of their absorptive capacity. Studies of luminol-dependent chemiluminescence in peripheral blood neutrophils in children with recurrent respiratory infections revealed changes in oxygen-dependent metabolism depending on the clinical variant of complicated infection. In the group of children with broncho-obstructive syndrome, the background chemiluminescence parameters of peripheral blood neutrophils were characterized by faster time to chemiluminescence curve peak. Chemiluminescence indices induced by opsonized zymosan showed a lower time of reaction to stimuli, decreased intensity of “respiratory burst”-associated luminescence, and decreased trend for activation index of peripheral blood neutrophils. Study of luminol-dependent chemiluminescence peripheral in blood neutrophils in children with hypertrophy of pharyngeal tonsils did not reveal changes in the background chemiluminescence levels. Chemiluminescence evaluation upon stimulation of peripheral blood neutrophils by opsonized zymosan caused a decrease in the stimulated response time, lower maximal “respiratory burst”, and decrease in AUC chemiluminescence. Thus, kinetics of spontaneous chemiluminescent response in peripheral blood neutrophils is impaired.in children with broncho-obstructive syndrome. Similarly, the in vitro neutrophil stimulation showed changes in chemiluminescent response kinetics and decreased reserve of oxygen-dependent metabolic capacity. In the children with hypertrophy of pharyngeal tonsil, we observed changes in chemiluminescent response of peripheral blood neutrophils only after opsonized zymosan induction. Compensatory metabolic capacity of peripheral blood neutrophils was retained in the opsonized zymosan stress tests. The study results showed unidirectional changes in peripheral blood neutrophil phagocytic activity parameters both in children with broncho-obstructive syndrome, and in children with pharyngeal tonsil hypertrophy and recurrent respiratory infection.

The results of previous studies suggest pathogenetic role of immune system in the development of schizophrenia. Examination of adolescent and young adult schizophrenic patients showed that the activity/ level of distinct parameters of innate and acquired immunity correlates with acuity and severity of pathological process in the brain. Presumably, evaluation of immune system characteristics in patients with childhood schizophrenia, concerning severity of their clinical symptoms, along with potential therapeutic aspect, may be the basis for early diagnosis of these conditions, and monitoring and prognosis of the further progression of the disease. The objective of our study was to compare clinical and immunological indices in children with schizophrenia to analyze the possibility of using these parameters for determination of the degree of activity of the pathological process. Sixty-two patients (39 boys and 23 girls) from 4 to 17 years of age with childhood schizophrenia were examined. Psychopathological and psychometric methods (PANSS and CGI-S scales) were used to assess mental state of the patients. Immunological parameters were determined in blood serum taken by fingerprick. Activity of leukocyte elastase (LE) and a1-proteinase inhibitor (a1-PI) was determined by spectrophotometric method. To determine the level of autoantibodies to S-100B and MBP, we used enzyme immunoassay. The study revealed activation of innate (by activity of LE and a1-PI) and acquired (by the level of autoantibodies to S-100B and MBP neuroantigens) immunity markers in blood serum of children with schizophrenia. Correlation analysis showed the significant positive correlation between complex evaluation of activation level of the immune system and severity of the patients’ state on the CGI-S scale (r = 0.64, p < 0.0001), as well as severity of negative symptoms according to the PANSS scale (r = 0.34, p = 0.0077). The revealed correlations suggest an opportunity for using immunological parameters (LE and a1-PI activity, and antibodies to neuroantigens), as the additional laboratory criteria for the assessment of clinical state in patients with childhood schizophrenia.