The incidence of acute respiratory infections (ARI) in children is significantly higher than in adults. The largest number of registered cases occurs in children under 7 years of age. Against the background of the SARS — COV2 pandemic, there is a frequent intercurrent or combined course of ARI. A large taxonomic diversity of ARI pathogens, a high frequency of combined infection, the ability of pathogens to develop resistance to chemotherapy drugs significantly limit the arsenal of therapeutic and preventive options.

   All this determines the relevance of studying the effectiveness of probiotics as a means of treating and preventing ARI in children.

   Objective of the study: to evaluate the effectiveness of probiotics in the treatment and prevention of ARI in children based on a critical analysis of literary sources.

   Methods. An analysis of literary data presented in the scientific systems PubMed, EM BASE, Web of Science and Trip from December 2000 to June 2024 was carried out, dedicated to the clinical use of probiotics for ARI in children. The following keywords and phrases were used as a search query: respiratory infections, microbiota, immunity, cytokines, macrophages, secretory IgA, T-regulatory cells.

   Results. Clinical studies of recent years confirm that probiotics (mostly Lactocasebacillus GG, L. casei, Bifidobacterium spp.) reduce the frequency, duration and severity of acute respiratory viral infections in children by modulating the immune response (increasing the level of secretory IgA, stimulating the production of IFN-γ and suppressing the synthesis of proinflammatory cytokines). Probiotics have a strain-specific immunomodulatory effect on epithelial cells and cells of the immune system. Preventive use of probiotics reduced the risk of developing ARI by 10–32 %. The use of probiotics in ARIs reduced the duration of the disease by 0.5–1.5 days, decreased the likelihood of an uneven course and the need for antibacterial drugs by 18–25 %.

   Conclusion. The use of probiotics helps to reduce the frequency and duration of ARI episodes, as well as reduce the frequency of secondary bacterial complications. Their use is considered as one of the key tools for ensuring an effective immune response and increasing the resistance of the macroorganism to respiratory pathogens. To expand the range of probiotic strains used, to clarify their clinical and immunological effects, it is advisable to conduct further scientific research in this area.

   Relevance. The increasing incidence of eosinophilic gastrointestinal diseases among the pediatric population entails the need to understand the etiology and pathogenesis of this pathology in order to improve the quality of diagnosis and treatment of this group of diseases.

   Materials and methods. In the search engines PubMed, ScienceDirect, Wiley Online Library, SpringerLink, RusMed, eLibrary.ru A search was conducted for scientific papers by keywords: eosinophilic gastrointestinal diseases, eosinophilic esophagitis, eosinophilic gastritis, eosinophilic enteritis, eosinophilic colitis, eosinophilic infiltration, children, adolescents. The search depth was 12 years (2012–2024). The source search algorithm followed the principles of PRISMA. 515 foreign and domestic publications have been identified. The analysis includes 36 papers.

   Results. Currently, eosinophilic diseases of the gastrointestinal tract attract the close attention of scientists, which is associated with a significant increase in this pathology. Eosinophilic gastrointestinal diseases are a group of chronic immune-mediated diseases of the gastrointestinal tract characterized by gastrointestinal symptoms and pathological eosinophilic infiltration in the absence of secondary causes of eosinophilia with a depth of organ damage from the mucous membrane to the muscular and serous layer, which leads to severe violations of their structure and function. This group includes eosinophilic esophagitis, eosinophilic gastritis, eosinophilic enteritis and eosinophilic colitis. The presented review analyzes the results of modern scientific research on the epidemiology, pathophysiology and clinical features of eosinophilic gastrointestinal diseases in children. Diagnostic criteria are given. Modern approaches to the treatment of these diseases are considered. Most scientific publications are devoted to eosinophilic esophagitis, in the diagnosis and treatment of which a certain consensus has been reached. The management of children with eosinophilic gastritis, eosinophilic enteritis and eosinophilic colitis is particularly difficult, which determines the need for further study of the pathogenesis of these diseases.

   Conclusion: the number of scientific papers that have increased in recent years expands knowledge about eosinophilic gastrointestinal diseases in children, but it is worth striving to reach consensus on eosinophilic gastritis, eosinophilic enteritis and eosinophilic colitis.

   Relevance. The increasing prevalence of hypersensitivity reactions to dental materials among the population of any age entails the need to understand the diversity of the etiology of this problem in order to prevent allergic manifestations in dental practice.

   Materials and methods. Scientific papers were searched in the search engines PubMed, ScienceDirect, Wiley Online Library, SpringerLink, RusMed, eLibrary.ru by keywords: allergy to dental materials, allergy to metals, hypersensitivity to polymers, allergy to acrylates, allergy to latex. The search depth was 5 years (2020–2025). The source search algorithm followed the principles of PRISMA. 516 foreign and domestic publications were identified. A total of 41 publications from an electronic search in the above databases and 19 articles additionally found using a manual search were included in the analysis.

   Results. Among dental materials, metals and polymers are the most common chemical components that can cause hypersensitivity reactions. Hypersensitivity reactions can manifest as immediate hypersensitivity reactions (type I) to metals, latex and some polymers with clinical manifestations in the form of urticaria, angioedema, bronchospasm and anaphylaxis, or delayed hypersensitivity reactions, more often to metals with symptoms of contact allergic dermatitis. Dental materials with biocompatibility issues include composites, latex gloves, local anesthetics, endodontic materials, casts, and metals. The most common manifestations of allergies in dental patients are cheilitis and perioral dermatitis (25.6 %), burning mouth syndrome (15.7 %), lichenoid reaction (14 %) and orofacial granulomatosis (10.7 %). Common contact allergens were sodium thio-sulfate (14 %), nickel sulfate (13.2 %), mercury (9.9 %), palladium chloride (7.4 %), and 2-hydroxyethylmethacrylate (5.8 %). While dental clinic staff usually have contact dermatitis of the hands. The most common causes of contact allergic dermatitis in dental workers are metals, latex, antimicrobials, formaldehyde, preservatives, and methacrylates.

   Conclusion. To clarify the diagnosis, it is important to find out a detailed allergy-related medical history, clinical examination, and confirmatory tests such as patch tests and MELISA. The latest ELISA research method should be widely implemented in real practice.

   Introduction. Recent literature data show that vitamin D deficiency (VD) plays a role in the pathogenesis of bronchial asthma (BA), affecting the regulation of immune responses and remodeling of smooth muscles of the respiratory tract. The addition of VD to the basic therapy of BA in children is a promising area of research.

   Objective. To analyze the relationship of serum concentrations of 25(OH)D, periostin and TGF-β1 in blood serum, depending on the level of VD provision in children with asthma after pharmacological correction.

   Materials and methods. The study included 80 children aged 6 to 17 years (mean age 12 ± 3.2 years). When analyzing the results of VD-complementation, the children were divided into 4 subgroups: group 1a — 40 children with asthma before VD correction, group 1b — children with asthma after VD correction (n = 40), group 2a included 40 healthy children (comparison group) before correction, group 2b included children after correction of VD status (n = 40).

   Results. After taking VD, the level of 25(OH) increased in all examined children with asthma in the blood serum. The number of children with VD deficiency in children with asthma decreased from 72.5 % (n = 29) to 10.0 % (n = 29) (p = 0.000), and with VD deficiency increased 4.5 times (p = 0.001), among children with normal VD provision, the serum level was 25(OH)D increased 2.5 times (p = 0.028). In the comparison group, there was also a positive trend in children: after complementation, the number of children with VD deficiency decreased by 2 times, the number of children with VD deficiency increased by 18 %, and those with normal income by 33 %, but no statistically significant difference was found (p > 0.05). The median periostin in the group of children suffering from bronchial asthma was within the range of normal values (normal 132.4–859.6 ng/ml), but after taking VD it became statistically significantly lower than before taking VD (730.0 ng/ml [390.8; 1109.7] versus 428.0 ng/ml [365.75; 582.5], p = 0.000). The parameters of TGF-β1 were independent of VD intake and were in the range of standard values. In the course of the study, we established a negative correlation of moderate intensity between the level of 25(OH)D in the blood serum of children with asthma and the frequency of exacerbations of the disease.

   Conclusion. After pharmacological correction of the VD status, an increase in the level of 25 (OH) is noted in the blood serum of children suffering from asthma, and especially with mild severity of the disease. The median periostin in the group of children suffering from asthma decreased statistically significantly after taking VD, and the median TGF-β1 was independent of VD status and VD intake. A negative correlation of moderate intensity was revealed between the level of 25(OH)D in the blood serum of children with asthma and the frequency of exacerbations of the disease.

   Relevance. Down syndrome is one of the most common genetic diseases worldwide. People with this syndrome are at risk for developing immunodeficiency conditions. The article discusses the results of a study of TREC and KREC concentrations in children with Down syndrome.

   The aim of the study was to determine the concentration of TREC and KREC in children with Down syndrome compared with healthy children.

   Materials and methods. A prospective study was conducted to determine the content of TREC and KREC in the bloo d of children and adolescents with Down syndrome.

   Results. It was found that the co ncentration of TREС in children with Down syn drome is significantly lower than in healthy children of the appropriate age, which indicates a violation in the development of the T-cell link of immunity. A similar pattern is observed for KREС levels, which indicates a violation of the maturation of B-lymphocytes responsible for the synthesis of antibodies.

   Conclusion. This study highlights the importance of early diagnosis and monitoring of the immune status in children with Down syndrome by determining the conc entration of TREС and KREС, which will allow timely corrective measures and prevent the development of complications.

   Introduction. Bronchial asthma in children is an urgent medical problem. Currently, there are separate clusters of BA variants and various phenotypes. ARVI is the most frequent trigger of BA exacerbations, which makes the study of interferon status relevant.

   Methods. A study of IFN-α and IFN-γ in the blood serum of children with AIBA (n = 60) and VIBA (n = 10).

   Results. An increase in IFN-γ was found in AIBA by 1.9 times and in VIBA by 1.7 times. An increase in IFN-α was observed in both AIBA (4.7 times, 2.95 ± 0.73 pg/ml) and VIBA (9.9 tim es, 6.24 ± 1.32 pg/ml). A decrease in IFN-γ in the blood serum was observed in moderate AIBA (1.23 ± 1.59 pg/ml) and severe AIBA (0.76 ± 0.64 pg/ml).

   Conclusion. Decreased IFN-γ content is an important factor in the severe course of AIB. As an additional marker for the diagnosis of BA phenotype, the use of IFN-α / IFN-γ ratio is proposed.

   Objective: the study to relationship between the concentration of transforming growth factor β1 (TGF-β1) in the blood serum of patients with bronchial asthma (BA), depending on the severity of the disease and the volume of basic therapy.

   Materials and methods. A comprehensive examination of 159 children suffering from atopic asthma was conducted, of which 79 (49.7 %) patients had mild asthma, 33 (20.75 %) had moderate asthma, and 47 (29.55 %) patients had severe asthma. The control group included 30 children of health groups I and IIa. All children included in the study had their serum concentrations of TGF-β1 determined by ELISA using Human TGF-β1 Platinum ELISA kits manufactured by Bender MedSystems GmbH, Austria (Bender MedSystems GmbH, Campus Vienna Biocenter 2, 1030 Vienna, Austria). Statistical processing of the obtained data was carried out using the Statistics 12.0 software package.

   Results. The results of the conducted studies have shown that TGF-β1 plays a significant role in the pathogenesis of asthma. And the study of changes in the concentration of this cytokine in patients depending on the volume of basic therapy makes us think about the development of new targeted therapeutic drugs to optimize pharmacotherapeutic approaches to the treatment of this disease.

   Conclusion. The results of the conducted studies showed that TGF-β1 not only plays a significant role in the pathogenesis of BA, but also affects the severity of clinical manifestations of the disease. It was found that in patients with severe asthma, TGF-β1 values were lower than in mild asthma (p = 0.009). And the study of changes in the concentration of this cytokine in patients showed the presence of increased values in patients receiving monotherapy with ICS. The results obtained are quite ambiguous and make one think about continuing research in this scientific direction.

   Introduction. The clinical features of asthma in individuals with high body weight have led to the identification of a specific phenotype: asthma in obese patients, where the presence and severity of obesity contribute to a more severe course of asthma and make it difficult to treat. Despite the increasing number of studies confirming the significance of the ADRB2 gene in the pathogenesis of asthma and obesity, the available data are rather contradictory and do not provide a definitive answer.

   Aim. Evaluation of the role of polymorphic variants rs1042713 and rs1042714 of the ADRB2 gene in children with BA and obesity.

   Materials and methods. A single-center observational cross-sectional pilot study was conducted on 161 children with a diagnosis of BA, with an average age of 12.6±0.2 years. The study participants were divided into two groups: the main group consisted of obese patients (n = 59), and the comparison group consisted of patients with normal body weight (n = 102). Genotyping was performed using the “Metabolism” kits from NPF “Litex” (Moscow) using the PCR-RV method on a CFX-96 Bio-Rad instrument (USA).

   Results. An increase in the frequency of detection of the 16Gly allele of the rs1042713 polymorphism in patients with asthma and obesity was shown (OR = 1.59; 95 % CI [1.01–2.50]). An association of the Gly16Gly genotype with an increased risk of uncontrolled BA in children with obesity was found (OR = 9,.68 [95 % CI = 1.16 –81.12]). In 59 % of cases, patients with mild asthma had the “wild” genotype Gln27Gln rs1042714 versus 37 % with moderate to severe disease (OR = 2.45, [95 % CI [1.23–4.91]) and the Gln allele (OR = 2.03, [95 % CI = 1.19–3.44]) the ADRB2 gene. The presence of polymorphic variants of the ADRB2 gene had a clinical implementation. Doses of topical glucocorticosteroids (TGCs) in children with obesity-related BA were significantly higher than in patients without obesity (250 [100—500] μg/day and 100 [0—250] μg/day. respectively, p = 0,0017) and were associated with the presence of the 16Gly allele of the rs1042713 polymorphism of the ADRB2 gene (Me 500 [250—750] μg/day, p = 0,0002) and the 27Glu allele of the rs1042714 polymorphism, which may be a potential predictive marker of response to inhaled corticosteroids in carriers of these ADRB2 genotypes in children with bronchial asthma.

   Conclusions. The presence of Arg16Gly and Gly16Gly genotypes and the Arg16 allele of the ADRB2 gene in patients with BA and obesity increases the risk of uncontrolled disease. The results obtained are important for identifying individuals at risk of uncontrolled BA in obese children, which allows for timely implementation of a set of preventive measures among them.

   Introduction. Sublingual immunotherapy is administered using allergens that contain varying amounts of antigen. Different manufacturers employ distinct application regimens. The study investigates the efficacy of “Antypollin”, a low-dose sublingual tablet containing birch allergen 0.1–1000 PNU combined with ascorbic acid.

   Materials and Methods. An open-label, comparative non-randomized trial was conducted involving 52 participants. We evaluated the effectiveness of sublingual tablets of birch pollen extract (1000 PNU) in relation to seasonal variations in pollen concentrations when used according to pre-seasonal–seasonal protocols for patients with seasonal allergic rhinitis. Additionally, the allergenic potency of these tablets was assessed by comparing them with solutions having known characteristics.

   Results. Allergenicity testing was performed on 40 subjects using prick tests with a solution of 1000 PNU/mL, resulting in an average papule diameter of 4 [IQR: 3–5] mm. This corresponded to approximately 50,000 EAA (Russian Unit of allergen activity). Total cumulative dose over the course amounted to 24,667 PNU, with half being administered prior to peak season onset. Specifically, within the first 42 days, 667 PNU were delivered, followed by two phases from day 43 to 66 and again from day 67 to 90, each providing 12,000 PNU. During the birch pollen period between April 28^th and May 11^th, 2025, annual mean pollen concentrations ranged from 1000 to 2500 grains per cubic meter. In the treatment group receiving Antypollin tablets, the Visual Analog Scale (VAS) score for rhinitis symptoms showed significantly lower values compared to controls (median VAS scores: 2 [IQR: 1–5] versus 7 [IQR: 4–8]; p < 0.001). Similarly, the total symptom-medication score (TCS) demonstrated significant improvement (p = 0.001), with median values of 12.7 [IQR: 8.3–18.1] versus 22.8 [IQR: 17.0–28.3]. At peak pollen period (April 21–27^th, 2025), pollen levels reached up to 14,500 grains per cubic meter. During this phase, while VAS symptom scores remained statistically different (5 [IQR: 3–6.5] vs. 7 [IQR: 5–8]; p < 0.01), the TCS did not achieve statistical significance (88%; median difference: 22.3 [IQR: 11.6–22.8] vs. 23.0 [IQR: 17.0–28.4]; p = 0.12). In contrast, during alder flowering periods characterized by lower pollen concentrations, weekly averaged median TCS scores in the Antypollin group were significantly reduced compared to control groups (10.6 [IQR: 5.9–14.1] vs. 14.9 [IQR: 14.7–19.4]; p = 0.01). Nasal and conjunctival symptoms differed markedly (6 vs. 9; p < 0.05), although medication usage only trended toward differences (3.43 vs. 9.71; p = 0.07). Symptom severity, measured via VAS, was halved relative to controls. Nasal complaints exhibited a 30 % reduction in median values (3 vs. 6), whereas ocular symptoms decreased by 33 % (3.5 vs. 5), though these results did not reach statistical significance (p ranging from 0.06 to 0.12).

   Conclusion. The study demonstrated that birch pollen tablets combined with ascorbic acid exhibit sufficient allergenicity and serve as an effective therapeutic agent under conditions where pollen concentrations approximate annual average levels. Patient complaint rates and medication consumption should be adequate for analysis of efficacy. After completing the first course of therapy, it was observed that high pollen concentrations elicit similar clinical manifestations in both the treatment and control groups. This indicates insufficient therapeutic effect following a single course. It is likely that more prolonged courses of maintenance therapy will be required to achieve sustainable immunotherapeutic outcomes.