This brief analytical review is devoted to spreading, etiology, pathogenesis, prophylaxis, and treatment of COVID-19 and “swine flu” causing pandemics in the 21st century. Both pandemics were caused by respiratory viruses belonging to different families, i.e., Coronaviridae (SARS-CoV-2) and Orthomyxoviridae (influenza A(H1N1)pdm09 virus), respectively. In most cases, pathogens enter human organisms via epithelial cells of the upper airways. Sometimes, these viruses infect intestinal epithelium. Given that symptoms of influenza and COVID-19 are similar, its diagnostics should always be based on laboratory results, especially, PCR evidence for specific RNA presence in clinical material. The paper describes similarities and differences in immune pathogenesis of the diseases. The main characteristics of two pandemic courses caused by SARS-CoV-2 and influenza A(H1N1)pdm09 are revealed. The presence of influenza vaccine and etiotropic chemotherapeutic agents, as well as preexisting immunity to influenza virus among elderly people in 2009 had a significant influence on morbidity and mortality during the influenza pandemic. The presence of antibodies to A(H1N1)pdm09 virus in sera of elderly people before the pandemic can be explained by the fact that some antigenic properties of A(H1N1) virus which circulated before 1957 were similar to that of A/California/07/09 (H1N1)pdm09. Consequently, morbidity and mortality among people older than 65 (main risk group) were low, while children and young adults suffered more often. The opposite pattern is observed for COVID-19, since mortality among the elderly population is high, while the children and young adults have an asymptomatic or mild form of a disease. A suggestion is made that population in the South-East Asia may have immunity against SARS-CoV-2, since coronaviruses with antigenic features similar to the pandemic one could circulate in that region and infect population without evident symptoms, while one or several recent virus variants caused severe disease and COVID-19 outbreak in Wuhan.

 

 

Incidence of the ophthalmic complications in autoimmune diseases is stably increasing over recent years, as well as overall increase in the number of autoimmune pathologies around the world, along with novel diagnostic approaches. According to the WHO estimates, the number of patients with visual impairment is estimated at 285 million people for 2010, causing blindness in 39 million cases. Among autoimmune diseases, diabetes mellitus, sarcoidosis and Behcet’s disease are most often complicated by these conditions. Dry eye syndrome is the most common eye complication associated with these diseases. Our aim was to describe eye complications in type I diabetes, sarcoidosis, and Behcet’s disease, as well as show the importance of research in the area, and to develop common criteria for the care of patients with ophthalmic conditions. The review considers main pathogenetic links, ethnic and genetic factors of ocular pathologies in autoimmune disorders, the main issues of timely diagnosis and the use of various schemes of conservative therapy. The results obtained upon analysis of the literature contain demonstrate the possible autoimmune nature of such eye pathologies, as uveitis and dry eye syndrome in diseases such as type 1 diabetes mellitus, sarcoidosis, and Behcet’s disease. Despite the ongoing research, there are many unresolved issues in the study of pathogenesis, as well as in therapeutic strategy. Therefore, the treatment of autoimmune eye diseases is a difficult task today, including treatment of the underlying disease, and local therapy of the visual organ. Since the primary immunopathology in the mentioned autoimmune diseases requires further studies, it is not possible to accurately predict the course of eye disease, possible complications and outcomes at the present time. Currently, there is only scarce information for creating uniform criteria for the treatment of uveitis and dry eye syndrome in autoimmune diseases. Their further development can contribute to establishment of the principles of medical care, in order to improve efficiency of treatment and quality of life in the patients. Further research and accumulation of data in the field are needed.

Morbidity and mortality rates in invasive mycoses determine the need to improve methods for their timely diagnosis by assessment the patients’ immune status. Evaluation of individual immune status allows the clinician to predict the development and course of fungal infections. At the same time, identification of opportunistic mycosis in immunocompetent patients should require a search for some hidden immune deficiency. Determining the cause of such immune defects can help develop an effective strategy for both etiotropic and immune therapy of patients with invasive mycoses. Currently, the functions of regulatory T lymphocytes that support immunological tolerance in fungal infections remain to be incompletely studied. In this review, we present experimental works which suggest that the regulatory T lymphocytes are able to suppress immune responses to fungi by stimulating the immunosuppressive environment. It was shown that regulatory T lymphocytes use Toll-like receptor 2 to achieve immunosuppression in Candida infections. The balance between the number and function of regulatory T lymphocytes is essential for elimination of fungal pathogens and protection against post-infectious immunopathological conditions. It was found that the regulatory T lymphocytes provide protection at an early stage of Candida infection, since, due to IL-2 suppression, they enhance Th17 differentiation and clearance of fungi. Moreover, at the later stages of infection, the regulatory T lymphocytes have an inhibitory effect. The balance between Th17 and regulatory T lymphocytes in mucosal lining is considered the main factor for distinguishing between commensal carriage and Candida albicans infection. The study is presented which indicate that disseminated candidiasis associated with expansion of regulatory T lymphocytes stimulates a Th17-cell response that controls the course of the disease. The mechanisms that control regulatory T lymphocytes homeostasis are essential for providing effective protection against pathogens, as well as for controlling the immunopathological conditions associated with Candida infection. The review presents data that have established the role of TGF-β1 in increasing the viability of regulatory T lymphocytes, which is correlated with the pronounced immunomodulating role of these cells at the later phase of Candida infections of the mucous membrane. It has been also demonstrated that the pulmonary regulatory Tlymphocytes are induced during cryptococcal infection, which predominantly suppresses Th2 cells, thereby supporting its course. Expansion of the regulatory T lymphocytes upon administration of IL-2/antiIL-2 complex during cryptococcal infection led to a decrease in IgE production and a decrease in allergic airway inflammation. It should be noted that refinement of prognostic value of the regulatory T lymphocytes in human fungal infections may substantiate the basic principles of targeted immunotherapy.

Bacterial extracellular microvesicles (BMV) are formed by nonpathogenic, pathogenic and opportunistic bacteria. BMV are spherical bilayer-membrane organelles containing different cargoes: lipopolysaccharides, pathogen associated molecular patterns (PUMP), DNA, RNA, signal molecules, proteins, antibiotic resistance factors, virulence factors, toxins providing various immune response options and conducive to the survival and pathogen dissemination in the human body. BMVs secretion play an important role in the ability of microorganisms to cause various diseases. BMV are involved in biofilms formation, help bacteria to obtain nutrition in a nutrient-poor conditions, to evade the host's immune response, provide communication and surviving in a stressful environment during infection inside the host. The heterogeneity of the biogenesis mechanisms causes differences in the BMV and their characteristics including virulence rate. BMVs host cells entering is mediated by several mechanisms and helps to activate innate and adaptive immune reactions. This review focuses on interaction study of BMV with various eukaryotic cells types including neutrophils, dendritic cells, macrophages, epithelial, endothelial cells. This interaction depends on bacteria species, type of target cell and number of vesicles and can lead to different responses: non-immunogenic, pro-inflammatory, cytotoxic. Subcellular and molecular mechanisms related to the involvement of extracellular microvesicles in host's immune response modulation are presented. Stimulation of immune response is provided by increased secretion of proinflammatory cytokines and chemokines. In some cases BMV use mechanisms to evade immune surveillance: anti-inflammatory cytokines secretion, alterations of phagocytosis and chemotaxis of macrophages, increasing the proteolytic cleavage of CD14 on the macrophage surface, alterations of antigen-presenting function of dendritic cells, T-cell proliferation suppression, reducing the pro-inflammatory cytokines secretion, evasion of host-immune cells direct interactions, destruction of neutrophilic traps. These features allow bacterial cells to survive in the human body, increase their invasive potential, and reduce the excessive inflammatory reactions leading to death of the pathogen itself and life-threatening damage of tissues and organs of the host. Further studies of these mechanisms will improve existing therapeutic approaches to the infectious diseases treatment.

Participation of blood platelets in the development of sepsis is clearly illustrated by hemocoagulation disorders and frequently observed thrombocytopenia. In the patients with sepsis, thrombocytopenia develops rapidly, with minimal platelet counts registered on the fourth day of observation, after which the platelet counts usually rise. Continuous thrombocytopenia and absence of a relative increase in platelets are considered predictors of patient death. The mechanisms of thrombocytopenia developing in sepsis are quite diverse, but the processes in periphery are prevailing, e.g., the so-called “platelet consumption” which is determined by their activation, chemotaxis and isolation in the microvasculature. Recently, a mechanism has been identified for the accelerated removal of platelets with desialized surface glycoproteins from the circulation. Sialidases, also known as neuraminidases, are widely present in viruses and bacteria, and pharmacological inhibition of sialidases is able to withstand thrombocytopenia in the infectious process. The key role of platelets in the development of septic shock was revealed. Sequestration of platelets in the microvessels of the lungs and brain (manifesting as thrombocytopenia) is accompanied by rapid serotonin release, thus underlying the main clinical manifestations, e.g., decreased blood pressure, heart rate and increased capillary permeability. To counteract sharp release of this mediator, pharmacological attempts are made to inhibit the SERT transporter by means of selective serotonin reuptake inhibitors. Blood platelets are key participants in the pathogenesis of multiple organ failure syndromes, such as acute renal damage, acute respiratory distress syndrome, myocardial dysfunction, and sepsis-associated encephalopathy. To restore impaired vascular permeability in these conditions, in particular, sepsis-associated encephalopathy, a pharmacological S1P receptor mimetic is under study. The review specifies possible pathogenetically significant targets that can be used to perform pharmacological correction of conditions associated with sepsis and concomitant thrombocytopenia.

Previous studies have shown that prolonged professional contact with chemical xenobiotics contributes to sensitization of immune system and development of typical immunopathological processes, i.e., allergies and autoimmune diseases. Origin and severity of immune system disorders depends on the spectrum and duration of exposure to adverse factors and patterns of professional activity at the chemically hazardous facilities. The study of structural and functional changes in cellular, humoral and some factors of innate immunity in people working and living in areas with unfavorable environmental conditions revealed a number of immunological disorders that can be characterized as secondary immunodeficiency conditions, which may manifest with increased frequency of acute respiratory infections and other chronic diseases. Much attention is given to prevention and treatment of secondary immunodeficiency conditions, which are associated with decreased numbers of lymphocytes expressing CD3, CD4, CD8. The purpose of the study was determined by recent positive experience of using highly effective drugs based on thymic regulatory peptides affecting various steps of homeostasis, in order to correct immune disorders caused by exposure to radiation and other toxic substances. The aim of this study was to evaluate changes in immunity and effectiveness of immune correction by means of immunotropic drugs, i.e., Thymogen nasal spray, and Cytovir-3 capsules, in the cohorts living and working under the conditions of heavy chemical exposure. We observed 249 persons aged 18 years to 63 years recruited from the employees of the “Polygon “Krasny Bor” State Enterprise. The people had longterm professional contacts with the components of industrial toxic waste were under examination. Group 1 consisted of the administration staff, group 2 included drivers of special cargo transport. The control group consisted of 137 employees at the car enterprises in Saint Petersburg. The duration of follow-up observation was 1 year. The patients with a detected decrease in cellular immunity received immunotropic drugs based on alpha-glutamyl-tryptophan (Thymogen nasal spray dosed (Thymogen, 62 persons), or combined encapsuleted Cytovir-3 drug (Cytovir, 31 cases). 14 days after finishing the course, a second immunological study was conducted. Following the immunotropic therapies, the subjects showed an increase in relative content of CD3⁺, CD4⁺, and CD8⁺ subpopulations, normalization of functional oxygen-dependent metabolism of polymorphonuclear neutrophil granulocyte system in the NBT test, as well as harmonization of the content of serum immunoglobulin contents. The one-year follow-up showed high effectiveness of these drugs, as shown by decreased incidence of acute infectious and lower exacerbation rates of chronic respiratory and gastrointestinal diseases. For the group 1 with working experience of 1 to 5 years, the persons who received Thymogen exhibited lower incidence of acute respiratory viral infections (a 37% decrease), like as less frequency of bronchopulmonary diseases (by 25% from the baseline). The patients with long-term work experience in an unfavorable area (Group 2), who received Thymogen, have shown four-fold reduction in acute respiratory morbidity, decreased frequency of other respiratory diseases (1.5-fold), and disorders of digestive organs (a 1.75-fold decrease). Among persons from the 1st and 2nd groups with work experience of up to 1 year, who received Cytovir-3, the SARS incidence decreased by 1.95 and 2.0 times, respectively. It is shown that timely detection of immune system disorders induced by the influence of complex harmful chemical factors, and administration of selective immunocorrecting therapy may contribute to reduction of acute and chronic morbidity in the people working under unfavorable environmental conditions.

Our aim was to evaluate immunomodulatory properties of an original bioflavonoid complex in experimental immune disturbances induced by cyclophosphamide (Cy). We have studied morphometric indexes of thymus and spleen, as well as blood leukocyte counts, cell proliferative activity in lymphoid organs, delayed hypersensitivity responses to T cell-dependent antigen, along with differentiation activity of bone marrow stem cells in experimental animals during Cy-induced immune suppression after a course of bioflavonoid treatment. Suspension of the bioflafonoid complex was introduced to the male mice (СВАхC57Bl/6)F1 aged 12- 14 weeks at a daily dose of 2 mg/animal (80 mg/kg), per os, using gastric catheter, over 14 days. Cytostatic immunosuppression was produced by a single intraperitoneal Cy injection. Proliferative activity of spleen and thymic cells was determined by standard method with Н3 -thymidine incorporation in the 72-h cell culture. Cellular immune response was assayed by the degree of delayed-type hypersensitivity development in response to sheep erythrocytes. The number of hematopoietic progenitors was evaluated by culturing bone marrow cells in methylcellulose-based medium. The experiments have shown mitigation of immunosuppressive effects induced by Cy, in the course of bioflavonoid complex treatment, with respect to absolute and relative mass of lymphoid organs and leukocyte numbers in peripheral blood. Moreover, we have demonstrated decreased effects of Cy treatment upon the spontaneous activity of spleen cells, mitogen-induced thymocyte and splenocyte proliferation, intensivity of delayed-type hypersensitivity response that reached the values of intact animals. Following the course of bioflavonoids, we have revealed an increase in early hematopoietic progenitors. Alleviation of Cy-induced suppressive effects upon cellular immune response, proliferation rates of immune cells, as well as stimulation of hematopoietic stem cell functions suggest a sufficient capacity of the original bioflavonoid complex for modulation of immunity and hematopoiesis, thus presenting experimental proofs for its potential usage as an adjuvant treatment of the patients with malignant diseases.

Numerous pathogens express arginine deiminase, an enzyme that catalyzes the hydrolysis of L-arginine in a chain of biochemical reactions aimed at the synthesis of ATP in bacterial cells. L-arginine is a semi-essential, proteinogenic amino acid that plays an important role in regulating the functions of the immune system cells in mammals. Depletion of L-arginine may cause a weakening of the immune reaction. In order to improve the conditions of dissemination, many pathogens use a strategy of L-arginine depletion in the microenvironment of host cells. Bacterial arginine deiminase can be a pathogenicity factor aimed for dysregulating the processes of inflammation and immune response. In general, the effect of arginine deiminase on immune cells may result into disturbed production of regulatory proinflammatory molecules, such as NO, and related substances, inhibition of activation, migration and differentiation of individual leukocyte subsets. The aim of this study was to investigate the effect of arginine deiminase on the formation of inflammatory infiltrate in murine air pouch model of streptococcal infection. Materials and methods: The study was performed using S. pyogenes M49-16 expressing arginine deiminase and its isogenic mutant S. pyogenes M49-16delArcA with inactivated arginine deiminase gene. The flow cytometry analysis of the inflammatory infiltrate leukocytes subpopulation in mice infected with the original strain of S. pyogenes M49-16 and its isogenic mutant S. pyogenes M49-16delArcA at different periods of infection was performed. It was shown that the inflammation reached its peak 6 hours after streptococcal inoculation, being more pronounced in mice infected with the mutant strain. Тhis finding was affirmed by a simultaneous and more pronounced increase in the absolute numbers of all leukocyte subsets in the focus of inflammation in this group of mice when compared to mice infected with original bacterial strain. Despite the decrease in the absolute number of all leukocyte types in the inflammatory infiltrate in both groups of mice for 24 hours, this trend was more pronounced in the group of mice infected with mutant microbial strain. Comparison of the inflammatory infiltrates developing in mice infected with original versus mutant strains showed that arginine deiminase may be a pathogenicity factor leading to dysregulation of protective immune response, due to impaired migration of white blood cells to the site of infection.

Mechanisms of recognition and effector responses of immune system upon initiation and maintenance of immune-mediated inflammation and tissue damage in inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis (UC), have been actively studied over recent time. Existing evidence suggests these diseases to be caused by abnormal immune response against intestinal flora microorganisms in genetically susceptible individuals. Despite available data on the features of immune disorders in ulcerative colitis and Crohn’s disease, there are still many questions about the involved minor lymphocyte subpopulations and contribution of various functionally active molecules, which play a key role in recognition and initiation of the immune response and can be considered biomarkers of a pathological process in inflammatory bowel diseases. The populations of T lymphocytes with γδT cell receptor, B1 cells and NK T lymphocytes are of greatest interest, as well as functionally active TLRs (Toll-like receptors), CD89, CD314, etc. Due to substantial progress in studying the nature of recognition and activation of the immune cells, the paper presents phenotypic and functional characteristics of major and minor subpopulations of peripheral blood lymphocytes observed in 25 patients treated at the Surgery Department of the State Institution “Minsk Regional Clinical Hospital” (Republic of Belarus) from 2018 to 2020. The detected changes in peripheral blood lymphocyte phenotype of inflammatory bowel diseases patients suggest distinct immunological profiles prevailing in the damage mechanisms in Crohn’s disease and ulcerative colitis. I.e., in Crohn’s disease patients, B1 lymphocytes with CD19⁺CD5⁺ and NK cells in combination with increased CD56^bright population, as well as NK T cells with anti-inflammatory and regulatory activity are involved into genesis of the disease. In ulcerative colitis, T, B, NK lymphocytes with pro-inflammatory phenotype and T lymphocytes with γδ T cell receptor may play a pathogenetic role in maintenance of chronic inflammation. With respect to functional significance of activating receptors, the number of TLR4- и CD89-positive cells may be used for developing immunological criteria/ biomarkers of therapeutic efficacy of new drugs. Studying interactions between innate and adaptive immunity will open new perspectives in understanding immunological disorders associated with chronic gastrointestinal inflammation.

Bladder cancer is the 7th most commonly diagnosed cancer in males worldwide and the 11th when both genders are considered. Seventy five per cent of bladder cancer cases are non-muscle invasive bladder cancer (NMIBC). Bacillus Calmette–Gu rin (BCG) immunotherapy remains the standard intravesical agent for NMIBC. The exact mechanism by which BCG prevents recurrence is unknown. The aim of this study was to evaluate NLR4 gene expression and IL-1β as possible prognostic indicators for NMIBC recurrence and BCG treatment failure, and to detect the difference in their levels among muscle invasive bladder cancer (MIBC) and NMIBC that may aid in primary differentiation between cases. This study was conducted in 30 patients who had NMIBC and 17 patients who had MIBC. Urine samples were obtained in sterile cups before operation. From NMIBC cases, four more samples were obtained as mentioned below. Evaluation of NLR4 gene expression was performed in pre-surgical sample for MIBC and in 4 samples for NMIBC: pre-surgical sample, sample collected 4 hours after the 3rd dose of BCG instillation, and samples collected during follow up (3 and 6 months post-surgically). There was statistical significant increase in NLRP4 expression levels in NMIBC (CT=0.87±1.48) compared to MIBC (CT=2.82±2.07). As far as we searched, no published results were found regarding comparative gene expression levels between NMIBC and MIBC cases. Gene expression in recurrent cases was higher in pre-surgical urine samples than in non-recurrent cases. The expression level further increased up to 21 fold than the pre-surgical level in the sample taken after injection of the 3rd dose of BCG. This level decreased distinctly to become 1-fold increase over pre-surgical level at the 3rd month follow up then to only 0.9-fold at the 6th month. In non- recurrent cases, gene expression level started pre-surgically in much lower levels than those encountered in recurrent cases. There were 11-fold increase in expression level after 3rd dose of BCG instillation and then decreased to be 5.6 folds higher in the sample taken at 3rd month follow up than in presurgical samples. Gene expression further decreased to become 4.1 fold higher in samples taken at 6 month follow up than the pre-surgical levels. IL-1β levels were estimated for NMIBC and MIBC cases in urine samples pre-surgically and during BCG therapy in case of NMIBC before and 4 hours after the 3rd dose and during 3rd month follow-up of those cases for searching its possible use of for primary differentiation between NMIBC and MIBC, and also as a prognostic factor for possible recurrence in case of NMIBC cases. The level of IL-1β was generally higher in pre-surgical samples (0.62±0.12 pg/ml) when compared to its level before the 3rd dose of BCG induction therapy (0.53±0.13 pg/ml). Its level was distinctly higher four hours after administration of the 3rd dose BCG (1.96±0.62 pg/ml) than both previous levels. Levels decreased bellow pre-surgical level at 3rd month follow up (0.57±0.099 pg/ml). The levels of IL-1β estimated in samples collected four hours after the 3rd dose BCG was higher in cases that showed recurrence later on than non-recurrent cases. The levels decreased in both cases and became higher in non-recurrent cases (0.64±0.05 pg/ml) than in cases already developed recurrence at the 3rd month diagnosed during follow-up (0.45±0.05 pg/ml). To conclude, on following NLRP4 gene expression and IL-1β levels during BCG administration among recurrent and non-recurrent cases of thirty NMIBC cases, there was a significant statistical difference in both levels for the samples collected after the third dose BCG, being higher in patients who showed subsequent recurrence at the 3rd and 6th month of follow-up. If these preliminary reported findings will be confirmed in upcoming larger cohort’s studies, it could be promising in prognosis of such cases, with the possibility of early manipulation of individualized treatment schedule, keeping patients most probably prone to encounter recurrence safe from possible side effects of BCG therapy. The assessment of NLRP4 expression and IL-1β levels could help predict failure of BCG therapy, playing an appreciable role in early deciding radical surgery. When comparing NLRP4 expression and IL-1β levels between MIBC and NMIBC cases, increased values were noted among non-invasive ones. This finding may serve as a possible diagnostic tool, which represents a challenging issue. Hence, cut-off values for gene expression and cytokine level are to be specified.

Influence of double-stranded RNA (dsRNA) from Saccharomyces cerevisiae yeast upon expression levels of the macrophage genes encoding TLR3 receptor, interferons alpha and beta (IFNα, IFNβ), 2’,5’-oligoadenylate synthetase (OAS) and protein kinase R (PKR) enzymes has been studied in the J774 mouse histiocytic cell culture and in vivo in Balb/c mice. It has been shown that dsRNA exerts a selective activating effect on genes of TLR3 receptor, antiviral proteins IFNα, IFNβ, and OAS, both in vitro and in vivo. With J774 cell culture, the highest induction capacity was observed for the IFNβ gene: 365 to 802-fold. The stimulatory effect was dependent on the dose of dsRNA in the range of 16.9 to 125 μg/ml. The preparation enhanced IFNα gene activity to lesser degree (more than 10-fold), TLR3 and OAS (3 to 4-fold), while the expression levels for these genes were not significantly dependent on the dose of dsRNA. The stimulating effect of dsRNA was dosedependent in murine peritoneal macrophages. The maximum activating effect of the preparation was shown upon administration of the effective antiviral dose (0.5 mg of dsRNA/kg). Five hours after intraperitoneal injection of dsRNA, the highest level of mRNA synthesis was observed for IFNα (54-fold), OAS (43-fold) and TLR3 (28-fold) genes. Expression of the IFNβ gene increased to a lesser degree (9-fold). An increase in the dose of preparation to 1.5 mg/kg led to decrease of the stimulatory effect. Expression levels of the IFNα, TLR3, and OAS genes in that case decreased by 2-4-fold as compared to a lower dose, and the PKR gene expression was 5-fold lower compared to the control. One day after dsRNA administration, a tendency was observed for both experimental groups towards a decreased transcription of macrophage genes, if compared with the 5-hour term. The weakening of gene activity was less pronounced in animals treated with dsRNA at the dose of 1.5 mg/kg. The transcription indices for IFNβ, OAS, and TLR3 genes were much higher during this period (5-10-fold higher than the control values). The dynamics of PKR gene transcription in both experimental systems was significantly different from the expression of other studied genes. The dsRNA preparation at this dose range did not have a pronounced stimulatory effect upon expression of this gene. A moderate increase in PKR gene activity in macrophages of mice was observed only a day following intraperitoneal administration of dsRNA. Concentrations and length of dsRNA molecules are known to be critical factors to the PKR gene activation. An ability to increase the expression of the gene is shown at low dsRNA concentrations (10-7 g/ml and below), while highly polymeric dsRNAs weaken the gene activity. Since the doses and concentrations of dsRNA used in our experiments were significantly different from those mentioned above, it could, in general, affect regulation of PKR gene transcription towards reduction of the stimulatory effect.

The article presents the results of the work performed by the laboratory of molecular diagnostics at the Medical Center “Health Care of Mother and Child” for the diagnosis of primary immunodeficiency in Sverdlovsk region over 5 years. The laboratory was organized in 2009 to verify the diagnosis of monogenic hereditary diseases included in the Neonatal Screening Program in the Russian Federation, e.g., phenylketonuria, cystic fibrosis, classical galactosemia. Over time, the range of diagnosed nosologies expanded, and since 2014, the laboratory has included in studies of a new group of disorders, i.e., congenital errors of immunity. Every year the Regional Registry of patients with primary immunodeficiencies (PIDs) replenished by 20 to 70 persons, thus comprising 15 to 43% of the entire Russian Registry for these conditions. As of 03/01/2020, the registry of patients with a clinical diagnosis of “primary immunodeficiency” consisted of 526 people, more than half of them (275) being children under 18 years of age. According to the expert calculations, the frequency of detected PID cases in the Sverdlovsk region is 1:10 480 inhabitants, which indicates not only high level of the existing clinical immunology service, but also the high expected frequency of PID in the region. Until 2014, verification of the “primary immunodeficiency” diagnosis in the patients from Sverdlovsk region was traditionally carried out in Moscow clinics (Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Moscow Research Centre for Medical Genetics). Over 6 years of cooperation between regional immunological service with the medical genetic center, 47 children received molecular genetic confirmation of the diagnosis of congenital immunity errors at the laboratory of Regional Medical Center “Health Care of Mother and Child”. The authors present the data of Regional Registry of patients, classified into nosological forms of immune-dependent pathology and provide a detailed description of diagnostic procedures for the patients with various PIDs. A deletion of chromosome 22 (Di Giorgi syndrome) was found in 43 people, mutations in the Btk gene (X-linked agammaglobulinemia) were revealed in 7 patients and 6 members of their families, Nijmegen syndrome was confirmed in 1 child, a familial case of ADA-deficiency, difficult for diagnostics, was decided. The results of the study encourage the authors for further expansion of the spectrum of detectable disorders diagnosis, and give a hope that development of regional laboratories at this level may improve the diagnostic algorithm for PID diagnostic procedures in Russia, i.e., from prenatal and neonatal screening to the development of gene therapy for certain forms of immune-dependent disorders.

Platelets are central participants in hemostasis, and also contribute to the host inflammatory and immune responses. Platelets are known to have a direct effect on the formation of neutrophil extracellular traps. Moreover, the patients with systemic lupus erythematosus exhibit multidirectional disturbances in the functional activity of platelets and neutrophils. Changes in inflammatory and thrombotic events can be considered predictors for adverse clinical course in systemic pathology. The aim of present study was to evaluate the possible role of platelets in maintaining increased netosis in patients with systemic lupus erythematosus. Blood platelets and white blood cells from 29 patients with systemic lupus erythematosus (SLE) were subject to the study. We have registered the in vitro effects of platelets upon formation of extracellular traps by autologous neutrophils under the conditions of co-cultivation for 30 minutes (vital NETosis) and 150 minutes (suicidal NETosis), as well as the relationships between the platelet counts, their activity and the number of NETs observed. It was found that the severity and direction of the platelets effect upon NETosis in vitro cultures depends on the degree of activity of disease: in the 1st degree of SLE, the effect of platelets did not differ from healthy individuals, i.e., intact platelets suppress NETosis (p = 0.002), whereas ADP-induced patelets did not exert any effect); at the 2nd degree of activity, both intact and activated platelets increase NETotic activity (p = 0.03 and p = 0.04 for intact and activated platelets, respectively). In the patients with 3rd degree of the disease activity, platelets did not affect formation of NETs. Hyperactivation of platelets was detected in SLE patients, mostly pronounced in the cases with 2nd degree of activity. However, we have not revealed any significant relationships between the count of platelets, their functional activity (according to results of ADP-test aggregation), and the indexes of NETosis. At the same time, the counts of neutrophil extracellular traps in bloodstream depended on the concentration of C-reactive protein (r = 0.58; p = 0.02), the titer of autoantibodies (anti-SS-A and anti-SS-B) (r = 0.66; p = 0.04 and r = 0.76; p = 0.02, respectively), rheumatoid factor (r = 0.73; p = 0.007) and circulating immune complexes (r = 0.68; p = 0.02). The obtained results indicate that the platelet/neutrophil interactions are not the leading cause for increased NETs numbers in SLE, compared to significantly higher effects of soluble autoagressive factors.

The study covered 30 apparently healthy individuals and 38 patients with systemic scleroderma. The patients gave their consent to participate in the study in accordance with the World Medical Association Declaration of Helsinki in the current (2013) version (ACR/EULAR). The donors and patients had their blood tested for catalase antibodies with immunoenzyme assay and using magnetic sorbents upon hospital admission and before discharge. It was found that the patients with systemic scleroderma had a reduced oxidase activity of catalase as well as elevated catalase antibodies, compared with the controls. We revealed a statistically significant regularity that the concentration of catalase immunoglobulins is associated with activity and course of the disease. To assess the activity of systemic scleroderma we performed a complex evaluation of two parameters: enzymatic activity and catalase antibody levels. It was established that catalase autoantibodies are mostly revealed in patients with high-activity scleroderma, subacute and acute course of the disease, and when the lungs, skin, kidneys, joints and nervous system were involved, which was conclusively confirmed by a correlation analysis. It is especially important that catalase antibodies should be revealed at early stage of the disease development; they are of especial diagnostic importance, and their changes over time may form the basis for assessing efficiency of administered therapy. The changes in biochemical activity of catalase, elevated antibody titers provide additional criteria of diagnosis in systemic scleroderma. Monitoring of these parameters in hospital settings helps to evaluate the effectiveness of administered therapy and adjust its correction, which is confirmed by inclusion of such extracorporal techniques as plasma separation into the combined treatment schedules. Studying biochemical activity of catalase and formation of catalase antibodies expands our understanding of scleroderma development and opens new avenues for research.

B cell stimulation develops upon vaccination, thus causing occurrence of activated B cells (plasmoblasts) in bloodstream. Similar cells are also observed in some viral infections. The contents of plasmablasts may be a marker of successful vaccination, or a diagnostic feature of ongoing infection. The plasmablasts are normally represented by a small cell subpopulation which is not easy to detect. A study was performed with 15 healthy volunteers who were subjected to a single immunization with a recombinant vaccine against hepatitis B virus. To identify the plasmablasts, we have used labeled antibodies prepared in our laboratory. These reagents were previously validated for counting the plasmablasts. Different gating strategies for plasmablast gating have been compared. Upon staining of lymphocytes from immunized volunteers, we observed a distinct cluster of plasmablasts with CD27⁺⁺CD38⁺⁺ phenotype using the following antibody set: CD19-PE, CD3/CD14/CD16-FITC, CD27-PC5.5 and CD38-PC7. Inclusion of a CD20-FITC antibody into the panel caused an increase of CD27⁺⁺CD38⁺⁺ plasmablast ratio among CD19⁺ lymphocytes to > 60%. Upon substitution of CD38 antibody by anti-CD71, a distinct plasmablast cluster was again revealed, which contained ca. 5 per cent В cells. Two strategies for the plasmablast gating using the CD27/ CD38 and CD27/CD71 combinations were compared in dynamics with lymphocyte samples from a single vaccinated volunteer. When applying the CD27/CD38 combination, a sharp and pronounced plasmablast peak was registered on day 7 post-vaccination. With CD27/CD71 combination, the peak was extended between day 7 and day 14 following immunization. Hence, time kinetics of the CD27⁺CD71⁺ population proved to be different from occurrence of classic plasmablasts with CD27⁺⁺CD38⁺⁺ phenotype. This finding suggests that the CD27⁺⁺CD71⁺population contains both plasmablasts and other types of activated B cells. A minor HBV surface antigen was prepared and labeled with phycoerythrin (HBsAg-PE), thus allowing to quantify the antigen-specific plasmablasts. The results of HBsAg-PE-based detection of antigen-specific cells were in compliance with the data obtained by ELISpot technique. At the present time, we use the original plasmablast gating technique for detection of activated B cells in SARS-CoV-2 infection. At the next step, this technique will be applied to sorting of antigen-specific B cells, thus permitting sequencing of Ig genes and design of novel human antibodies against viral antigens.

B cell stimulation develops upon vaccination, thus causing occurrence of activated B cells (plasmoblasts) in bloodstream. Similar cells are also observed in some viral infections. The contents of plasmablasts may be a marker of successful vaccination, or a diagnostic feature of ongoing infection. The plasmablasts are normally represented by a small cell subpopulation which is not easy to detect. A study was performed with 15 healthy volunteers who were subjected to a single immunization with a recombinant vaccine against hepatitis B virus. To identify the plasmablasts, we have used labeled antibodies prepared in our laboratory. These reagents were previously validated for counting the plasmablasts. Different gating strategies for plasmablast gating have been compared. Upon staining of lymphocytes from immunized volunteers, we observed a distinct cluster of plasmablasts with CD27⁺⁺CD38⁺⁺ phenotype using the following antibody set: CD19-PE, CD3/CD14/CD16-FITC, CD27-PC5.5 and CD38-PC7. Inclusion of a CD20-FITC antibody into the panel caused an increase of CD27⁺⁺CD38⁺⁺ plasmablast ratio among CD19⁺ lymphocytes to > 60%. Upon substitution of CD38 antibody by anti-CD71, a distinct plasmablast cluster was again revealed, which contained ca. 5 per cent В cells. Two strategies for the plasmablast gating using the CD27/ CD38 and CD27/CD71 combinations were compared in dynamics with lymphocyte samples from a single vaccinated volunteer. When applying the CD27/CD38 combination, a sharp and pronounced plasmablast peak was registered on day 7 post-vaccination. With CD27/CD71 combination, the peak was extended between day 7 and day 14 following immunization. Hence, time kinetics of the CD27⁺CD71⁺ population proved to be different from occurrence of classic plasmablasts with CD27⁺⁺CD38⁺⁺ phenotype. This finding suggests that the CD27⁺⁺CD71⁺ population contains both plasmablasts and other types of activated B cells. A minor HBV surface antigen was prepared and labeled with phycoerythrin (HBsAg-PE), thus allowing to quantify the antigen-specific plasmablasts. The results of HBsAg-PE-based detection of antigen-specific cells were in compliance with the data obtained by ELISpot technique. At the present time, we use the original plasmablast gating technique for detection of activated B cells in SARS-CoV-2 infection. At the next step, this technique will be applied to sorting of antigen-specific B cells, thus permitting sequencing of Ig genes and design of novel human antibodies against viral antigens.

Antinuclear antibodies (ANAs) represent a spectrum of autoantibodies targeted for various nuclear and cytoplasmic components of the cells. Indirect immunofluorescence assay (IIF) is the main detection method for “antinuclear factor”. A positive ANA test is usually reported as a titer and a pattern of fluorescence. The ANA patterns refers to the distribution of staining produced by antibodies that react with antigens located in nucleus and cytoplasm of HEp-2 cells. To standardize nomenclature and descriptions of the various fluorescence patterns of antinuclear factor (ANF), the Initiative of the International Consensus on ANA Patterns (ICAP) group was developed in 2014. The aim of ICAP is to promote consensus regarding nomenclature of ANA patterns, a microphotograph database, as well as classification depending on the employee skills. Information on the main characteristics, as well as specific clinical associations of the patterns is available at www.ANApatterns.org. In ANA classification trees, the patterns are indicated by the #AC (anticell pattern) alphanumeric code, being divided into nuclear, cytoplasmic and mitotic groups. Depending on the clinical significance and/or ease of recognition, this nomenclature focuses on the differences between the patterns described by specialists at competent and expert levels. Of the nuclear types, the most significant are homogeneous, speckled, dense fine-speckled, centromere, nucleolar, nuclear dots. The cytoplasmic types may be discerned into fibrillar, speckled, mitochondrial, Golgi, rods and rings. On leaders, behalf of the ICAP translation team is headed by the Full Member of Russian Academy of Sciences, Professor A.A. Totolian, under the auspices of the Russian Research Society of Immunologists. In this article, we present the Russianlanguage adaptation of the ICAP nomenclature, in order to ensure unification and standardization of ANA detection results in the patients with autoimmune diseases.

Hereditary angioedema (HAE) is a rare autosomal dominant disease caused by quantitative (type I) or functional (type II) deficiency in C1 esterase inhibitor (C1-INH). It may be caused by new mutations in up to 20% of patients. Prevalence of HAE is uncertain but is estimated to be approximately 1 case per 50,000 persons, without known differences among ethnic groups. C1-INH protein is a serine protease inhibitor that is important in controlling vascular permeability by acting on the initial phase of the complement activation, blood clotting, and fibrinolysis. Deficiency in functional C1-INH protein permits release of bradykinin, a key mediator of vascular permeability. Symptoms typically begin since childhood, worsening at puberty, and persist throughout the life, with unpredictable clinical course. The patients with HAE suffer from recurrent, acute attacks of edema that can affect any body sites, causing potentially life-threatening disorders (laryngeal edema). Results of clinical studies show that minor traumas, stress and medical interventions may be frequent precipitants of swelling episodes, but many attacks occur without an apparent cause. Pregnancy-associated hormonal changes may affect the course of C1-INH angioedema attacks by worsening, improving, or having no impact at all, but a higher percentage of pregnant women experienced an increase in C1-INH-HAE attack rates. Therapeutic options for patients with HAE are limited during pregnancy. C1-INH concentrate is recommended as the first-line therapy for pregnant women with HAE for on-demand treatment, shortterm and long-term prophylaxis, due to its safety and efficiency. Other therapies, e.g., treatment with fresh frozen plasma, androgens, icatibant, antifibrinolytics, may show variable efficacy, or cause undesirable side effects. The case below illustrates the successful treatment of HAE in a pregnant woman with C1 esterase inhibitor (C1-INH) concentrate. This patient had a very mild course of HAE during her lifetime and didn’t get any treatment. During pregnancy, she experienced a significant increase in the frequency of attacks, and the decision was made to start replacement therapy with a plasma-derived, double virus-inactivated C1-INH concentrate as a long-term prophylaxis throughout the full term of her pregnancy, before, during and after the cesarean section delivery.

Tumor necrosis factor (TNF) is an important proinflammatory and immunoregulatory cytokine with several unique protective and homeostatic functions. Since TNF is a mediator of several pathologies and is a part of “cytokine storm”, its significance for clinical immunology is due to the fact that this cytokine is a target of commonly used anti-cytokine therapy in autoimmune and inflammatory diseases. In scientific literature and textbooks TNF is often goes as “TNFa”, implying the existence of at least TNFβ (indeed, such term was used for about 10 years in 80s and 90s to designate lymphotoxin). However, already 25 years ago such designation of lymphotoxin was cancelled “on scientific grounds”. Therefore, both in Russian and in English the term TNF should be used without “alpha”. Labels of the reagents related to TNFb that are offered by commercial companies are misleading.