Vol 25, No 2 (2022)

The issues of non-specific immunoprophylaxis in the patients with new coronavirus infection have been raised since the WHO announced the COVID-19 pandemic. According to numerous studies, the new coronavirus infection is accompanied by manifestations of anosmia and dysgeusia. The purpose of this study was to perform a retrospective study of the relationships between nonspecific immunoprophylaxis of COVID-19 and conditions of anosmia/dysgeusia in the persons who underwent this infection in Sverdlovsk region over 2020.

We have studied clinical and laboratory data of 84 employees at the general medical institution providing emergency pediatric care. All participants suffered a single infection caused by SARS-CoV-2. Etiological diagnostics included mandatory virological PCR testing of biological samples. The concentration of antibodies to the virus was determined using a set of reagents for SARS-CoV-2-IgG detection (JSC Vector-Best, Novosibirsk, Russia). A sufficient part of this group (n = 41; 48.8% of total sample) reported self-administration of non-specific immunoprophylactic therapy of COVID-19 (without consulting a doctor) since the beginning of coronavirus pandemics. To this purpose, cholecalciferol, riamilovir, human recombinant IFNa-2b, umifenovir hydrochloride monohydrate, ascorbic acid, zinc acetate were used. In 58 cases (69% of total), clinical course of infection was complicated by loss of taste and sense of smell (group No. 1), in 26 people (31.0%), no changes in taste and sense of smell were detected (group No. 2). Statistical evaluation of the data was performed using STATISTICA v.12.5.192.5 package (StatSoft, Inc., USA). Along with basic statistics, cluster analysis was performed.

The use of cluster analysis allowed us to establish that there is a connection between the incidence of anosmia/dysgeusia and usage of distinct immunoprophylactic agents. In particular, the use of human recombinant IFNa-2b is protective in terms of reducing the number complications in COVID-19, especially, anosmia/dysgeusia caused by the new coronavirus. The use of this drug was associated with 8.5-fold decrease in the number of complications by (p = 0.03). Moreover, invasive intranasal usage of interferon, was associated with decreased hospitalization terms by 14.3% (p = 0.01); lower volume of lung tissue damage (p = 0.03), higher concentrations of IgG to SARS-CoV-2 at 2 months after reconvalescence (p = 0.001).

For the first time, data were presented on the relationship between usage of immunoprophylactic agents and manifestations of anosmia/dysgeusia in COVID-19. The protective role of human recombinant IFNa-2b has been shown in terms of reduced incidence of the disease complications, e.g., anosmia/dysgeusia, degree of lung damage, as well as development of an antiviral humoral immune response. The data obtained could be used to substantiate clinical recommendations for prevention of new outbreaks of coronavirus infection. The limitation of the obtained results is small number of cases, thus requiring additional studies in a wider sample of respondents.

Massive vaccination against SARS-CoV-2 appears to be one of the most important steps towards solving the problem of the COVID-19 pandemic, which threatened the lives of millions of people over two and a half years. To create anti-COVID-19 vaccines, both traditional approaches (inactivated vaccines), and innovative efforts were used, including the nucleic acid-based vaccines (mRNA, DNA vaccines) which appeared on the market. We constructed a plasmid (DNA vaccine) encoding the gene for the receptor-binding domain (RBD) of spike protein (S) of the SARS-CoV-2 virus. This DNA vaccine was named pVAXrbd. The polycationic carrier polyglucin-spermidine (PGS) and its recombinant RBD protein conjugate (PGS-RBD) were used to package pVAXrbd. By adding the negatively charged DNA pVAXrbd plasmid to polycationic PGS or PGS-RBD molecules, the complexes of polymers with plasmid DNA were formed by self-assembly, due to their non-covalent interaction. The aim of this work was to study cellular response induced by the DNA vaccine at various packaging options, as well as to analyze influence of the vaccine packaging upon development of the immune response. BALB/c mice were injected with DNA vaccine in three versions: “naked” pVAXrbd; plasmid pVAXrbd in PGS envelope; pVAXrbd in PGS-RBD wrapper. In control group, the animals were injected with the recombinant RBD protein. Cellular response was assessed by the IFNγ production using two methods, i.e., ELISpot and ICS using flow cytometry. It was shown that the DNA vaccine pVAXrbd, both per se, or as part of complexes, showed the ability to induce cellular immune response. The most effective cellular immune response was found in the group of animals immunized with pVAXrbd-PGS complex. Using ELISpot detection technique for this group, the largest number of cells responding by IFNγ release was registered upon stimulation with specific peptides; usage of ICS and flow cytometry for evaluation in this group showed higher percentage of IFNγ-producing CD4⁺ and CD8⁺T cells. This observed effect could be explained by DNA protection from nuclease action by the polyglucin-spermidine envelope. The pVAXrbd-PGS complexes may be also more efficiently recognized by antigen-presenting cells than naked plasmid DNA. The presented results show that the polyglucin-spermidine envelope provides an increase in immunogenicity of the DNA vaccine pVAXrbd, in terms of virus-specific T cell response.

Neutrophilic leukocytes play a key role for the joint damage in development of rheumatoid arthritis (RA). The specific death mode of these cells (netosis) may be an important reason of increase of cell-free DNA (cfDNA) in peripheral blood of the RA patients. Of great interest would be studies of alleged relationships between the of blood cfDNA contents being able of playing the role of an auto-antigen participating in the initiation of autoimmune reactions, and indices of neutrophil activation in this immunopathological disorder. The aim of the present study was to determine the levels of cfDNA in blood plasma of patients with RA depending on the clinical course of the disease, and to evaluate possible relationships between this index and activation of neutrophilic leukocytes. The study was conducted on 28 conditionally healthy donors and 63 patients with RA from the Rheumatology Department at the Clinic of Immunopathology (Novosibirsk). The level of cfDNA was determined using PicoGreen fluorescent dye. Neutrophils from the peripheral blood of donors and patients with rheumatoid arthritis were isolated in a Ficoll-Urografin density gradient. Neutrophilic leukocytes accounted for more than 98% of the fraction of isolated cells, and their viability was 99%. A portion of freshly isolated neutrophils was stimulated by phorbol myristate acetate. Concentration of myeloperoxidase in blood plasma of donors and patients with RA was determined using the Human MPO ELISA kit. It has been shown that the increased concentration of extracellular DNA in blood plasma of RA patients correlates with an higher degree of disease activity, and this parameter may serve as a relatively independent indicator of the disease intensity. A correlation was found between the level of cfDNA and common biochemical markers used to assess the activity of disease, i.e., DAS-28 and C-reactive protein levels in serum (p < 0.05). Decrease of cfDNA concentrations is detected during treatment of the RA patients. This is due to the expected prognosis, i.e., a decreased manifestation of the disease, which also means correct administration of therapy. A relationship was found between the level of cfDNA and blood myeloperoxidase concentration in RA patients. The data obtained during the study suggest a possible connection between increased concentration of extracellular DNA, and activation of neutrophilic leukocytes in rheumatoid arthritis, with increased netosis in the affected joints.

To date, only minimal attention has been paid to assessment of immunity state in patients with post-COVID syndrome. Influence of the SARS-CoV-2 virus on various systems in the body, including the immune system, may contribute to the development of disorders causing different diseases. At the same time, the patients suffering from the COVID-19 complications, including hospitalization and isolation from their family members, experience severe psychological and social stress. In almost every fourth case, these factors lead to development of the s.c. post-COVID syndrome. The aim of the present study was to evaluate the numbers of NK cells, levels of cortisol and characteristics of immune system disorders in the patients who underwent SARS-CoV-2 infection.

78 patients were examined 6 months after suffering COVID-19. We have assessed 25 parameters of the blood system (general blood test), 50 parameters of immune system, i.e., counts of T lymphocytes, B lymphocytes and their functional markers, NK, T-NK cell subsets, phagocytic components of immune system, as well as factors of humoral immunity, including total and specific immunoglobulins and complement fragments.

Our studies showed a sharp, three-fold decrease in the number of natural killers in more than 1/3 of the examined individuals. This decrease is accompanied by higher relative contents of T lymphocytes and T helper cells. The latter finding may be associated with a compensatory increase in T lymphocytes and dysregulation of the T cell link of immune system, thus requiring a more detailed study and, most likely, evaluation of the cytokine profile in such patients. Moreover, in some post-COVID patients, high levels of cortisol still persist, thus suggesting maintenance of chronic stress in these patients. Some changes in platelet counts are also important (increased levels of blood platelets and thrombocytocrit), which may promote later disorders of blood clotting system and development of thrombosis.

Currently, despite widespread use of the terms “systemic inflammation” (SI) and “systemic inflammatory response” (SIR), there are no generally accepted criteria for their verification. These processes are often identified (which is methodologically incorrect) and associated with an increase in pro-inflammatory mediators in the blood. However, SI is a complex process that requires integral criteria including assessment of SIR as reactivity level, and additional SI phenomena, such as microthrombosis, systemic alteration, and distress of the neuroendocrine system. At the same time, there is a need to assess individual CB indicators as a more affordable alternative for medical practice than the use of complex integral indicators. Our objective was to evaluate diagnostic efficacy of CRP and IL-6 levels as markers of acute and chronic systemic inflammation.

The data of patients with acute critical conditions of infectious and non-infectious genesis were analyzed to study acute systemic inflammation (SI), data of patients with autoimmune diseases, chronic organ failure and other chronic destructive diseases were analyzed to study chronic systemic inflammation (ChrSI). SIR severity was evaluated by the calculation of an integral index – reactivity level (RL). Differentiation of the inflammatory process to either classical inflammation (CI), or systemic inflammation was carried out using the previously proposed scale of SI, verification of chronic systemic inflammation was performed by means of ChrSI scale. SI (or ChrSI) was revealed in all groups of patients, and the frequency of SI registration in patients with acute conditions increased with development of multi-organ failure. The frequency of SIR was higher in all groups, thus confirming inability to equate these disorders. ROC analysis showed that CRP level had poor diagnostic efficacy on the development of SI/ChrSI (AUC < 0.6), and IL-6 level had very good diagnostic value (AUC 0.8-0.9). The prognostic value of the markers for detecting the SIR was higher, with AUC_IL-6 exceeding AUC_CRP. Thus, IL-6 in many acute and chronic pathologies is sufficiently closer to integral indices than C-reactive protein with respect to diagnostic efficiency, and the dynamics of IL-6 in blood may be used to predict and evaluate complications associated with acute and chronic SI, as well as to prescribe and monitor the results of anticytokine therapy.

Specific humoral immunity to SARS-CoV-2 develops due to the formation of neutralizing IgG, which can primarily block the receptor-binding domain of the viral S-protein. The duration of post-infection immunity, as well as avidity of circulating antibodies, play an important role in this process. The aim of this work was to evaluate the amounts of antibodies to SARS-CoV 2 S-protein, their avidity and neutralizing activity in the studied samples of the post-COVID patients versus vaccinated seropositive individuals. Materials and methods. A sample of 113 individuals was studied, which consisted of three experimental groups, i.e.: recovered, vaccinated, as well as recovered and vaccinated persons. Blood serum specimens of the individuals were studied for specific IgG to SARS-CoV-2, along with determination of their quantities (BAU/mL) using Vector-Best kits (Novosibirsk, Russia). The avidity index was determined using a kit manufactured by MedipalTech (Dubna, Russia). Neutralizing ability of the antibodies was assayed by means of ELISA with diagnostic kits from MedipalTech (Dubna, Russia), which resulted into percentage of neutralized S-proteins to RBD. Results. The average levels of IgG did not show significant differences between reconvalescents and vaccinated persons. However, both indicators were significantly lower than those from the groups who recovered from the disease and were vaccinated. A cyclic change in the numbers of antibodies was observed, along with most intensive drop in the level of immunoglobulins over first four months after the illness or vaccination. Despite initially similar levels of immune parameters in both groups, the decline of this index in “vaccinated” group was significantly higher than in the “recovered” group, thus allowing us to conclude that the amounts of specific antibodies in this group was shown to be decreased to zero levels as soon as by the 10^th month. IgG index among the «recovered and vaccinated» groups remained unchanged for the entire anamnestic period. Avidity index of the antibodies in vaccinated individuals was higher than in recovered individuals. Meanwhile, this index in both groups was characterized by stable increase over the observation period of 7 to 11 months. The highest levels of antibodies and their avidity were noted in the group of recovered and vaccinated individuals, due to the most complete activation of the immune system. A straight-line trend was revealed for the decreasing index of neutralizing activity during the considered time period. The overall pattern of thee results shows that the neutralizing activity of antibodies is largely determined by the amounts of SARS-CoV-2-specific immunoglobulins. Thus, the time dynamics of antibodies to SARS-CoV-2 in various groups of examined individuals was revealed. Direct correlation was established between the neutralizing activity and amounts of immunoglobulins, as well as the role of vaccination for increased avidity of antibodies.

The data are provided on applications of optical radiation at various spectral ranges in the treatment of disorders of ORL organs. Some issues of pathophysiological and immune changes of nasal mucosa in response to surgical alteration are considered for the early postoperative period. In order to increase efficiency of postoperative rehabilitation in the patients subjected to rhinosurgical interventions, we have used low-frequency ultrasonic cavitation in combination with photochromotherapy in complex treatment schedules. Assessment of clinical and immunological effects of this treatment was performed as based on the study of clinical and functional pattern at the early stages of postoperative period and stabilization of the cytokine profile. In general, an opportunity of using optical radiation at different wavelength was confirmed, as shown by studies of physical characteristics of light irradiation, explaining the mechanisms of action on the damaged mucous membrane, to apply inflammatory response to surgical trauma and restore immunological abnormalities. The work was carried out in order to draw attention to the non-drug methods of early rehabilitation of persons subjected to rhinosurgical interventions.

Over recent decades, multiple data were accumulated on immunotropic activity of Bifidum flora, based on effects of these bacteria on isolated lymphoid follicles, dendritic cells, B-cell aggregates, pro- and anti-inflammatory cytokines and chemokines, as well as participation of bifidoflora in the recognition of “non-self” during the development of microsymbiocenosis. The relevance of research in the field is associated both with fundamental issues of human host/microbiota symbiosis, but also with the prospects of practical application of the knowledge gained towards design of probiotics that affect the immune system. This article presents the results concerning effects of supernatant and bacterial cells of Bifidobacterium bifidum 791 (B. bifidum 791) strain in the model of human peripheral blood mononuclear cells (MNCs). We used the reference strain B. bifidum 791 (Russian Collection of Industrial Microorganisms from the GosNII Genetika Federal State Enterprise, Deposition No. AS-1247), which is used in production of the probiotic drug “Bifidumbacterin” (CJSC Ecopolis, Kovrov). Mononuclear cells (MNCs) were isolated from peripheral blood of 20 healthy donors. MNCs were stained with monoclonal antibodies for CD4, CD8, CD3, CD25, CD69, CD56 (Beckman Coulter, USA). Analysis of the cellular subsets was performed by multicolor flow cytometry with Cytomics FC500 instrument (Beckman Coulter, USA). The experiments were carried out in duplicate. The studies have shown that probiotic strains have an activating and modulating effect upon immunocompetent cells. The studied B. bifidum 791 strain had an immunomodulatory effect on the cells of nonspecific and adaptive immunity: it increased the percentage of CD69⁺ cells in the subpopulation of CD3⁺CD8⁺T lymphocytes, CD69 (%) and CD25 (%) NK cells, and promoted activation of cytotoxic lymphocytes. The supernatant of bifidobacteria had a more pronounced effect on MNCs. E.g., it increased the expression of CD69 by Th cells, induced the expression of CD25 by T cytotoxic cells, and increased the CD69 and CD25 expression (%) by NK cells compared to B. bifidum 791 bacterial cells. These data contribute to understanding the mechanisms of immunoregulatory influence of normobiota (in the Bifidobacteria models) by formation of symbiotic interactions “microbiota – host” and contribute to the development of a new research area, i.e., “infectious symbiology”. Further study of immunomodulatory activity of bifidoflora has the prospectives of searching and selection of Bifidobacteria strains, in order to create new targeted probiotic preparations.

Currently, experimental studies are actively conducted to assess the effects of low-molecular-weight polypeptide mediators on the immune system, in order to design new immunomodulatory drugs. However, the specific effects of individual peptides on the immune system of experimental animals and their offspring remains insufficiently studied, thus requiring relevant research in this aspect. Our study evaluated the effect of the peptide homologue of the of adrenocorticotropic hormone fragment (15-18) (laboratory code, KК1) on immunological parameters of pregnant rats and their offspring using experimental models of passive maternal smoking exposure.

The immunological parameters were studied in 96 pregnant Wistar rats weighing 200-300 g, exposed to passive tobacco smoking and receiving a synthetic peptide KK1, which is a structural analogue of the ACTH_15-18 sequence fragment (Acetyl-(D-Lys)-Lys-Arg-Arg-amide), as well as probable effect on their offspring tested on the 14^th day after birth (76 rats). Experimental rats were fumigated with tobacco smoke for 8 hours daily from the 1^st to the 20^th day of pregnancy. Synthetic peptide KK1 was administered to pregnant rats in the form of an aqueous solution at a dose of 40 mcg / kg / day five times a day for 10 days. Weights of whole body, thymus and spleen were determined in all animals, the number of leukocytes, thymocytes, splenocytes, myelocaryocytes, circulating immune complexes were assessed in accordance with common protocols for experimental laboratory animals. The data were analyzed by Mann–Whitney U test. The significance level was set at p < 0.05.

Administration of the KK1 peptide to both control and experimental pregnant rats was accompanied by multidirectional changes in the number of cells in lymphoid organs. The positive trend of shifts in immunological parameters when exposed to the peptide KK1 seems to be based on the possible reduction of the consequences of the toxic effect of tobacco smoke due to the anti-inflammatory effect of this drug, as well as its ability to limit the development of free radical reactions. It is shown that the studied peptide contributes to the positive dynamics of multiple immunological parameters in experimental animals subjected to passive smoking. Further studies are required to assess the mechanisms of immunotropic action of the ACTH_15-18 peptide homologue.