STUDY OF THE CIRCADIAN MOLECULAR CLOCK IN PAEDIATRIC PATIENTS WITH SEASONAL ALLERGIC RHINITIS: POTENTIAL APPROACHES TO TREATMENT

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Understanding of the relationship between the circadian molecular clock and allergic diseases continues to be studied and may be of practical importance for further selection of optimal treatment. The aim of this study was to evaluate the degree of mRNA expression of the circadian molecular clock genes bmal1 and per1 in buccal epithelial cells and to investigate the effi cacy of protocol treatment in children with seasonal allergic rhinitis, taking into account the time dependence. Material and methods. The study included 20 patients aged 6 to 17 years with a confi rmed diagnosis of seasonal allergic rhinitis (SAR). The control group included 7 healthy children of the same age with no history of allergic or chronic diseases. All patients with SAR were divided into 2 groups of 10 patients each, who received the protocol therapy in the morning (group 1) and in the evening (group 2) for 4 weeks. The expression of circadian molecular clock genes was studied by real-time polymerase chain reaction (real-time PCR) method by sampling the buccal epithelium of the children’s oral cavity in the morning (8:00 am) and in the evening (8:00 pm), with a repeat examination of the samples 1 month after treatment.Statistical analysis was performed using the GraphPad Prism 5.00 computer program (GraphPad Software, Inc., San Diego, CA, USA). The research design was discussed and approved at the meeting of the medical and ethical commission of the Ukrainian Medical and Stomatological Academy, protocol No. 188 dated 11/25/2020, where permission to conduct medical and biological research was issued. The research design was discussed and approved at the meeting of the Medical and Ethical Committee of the Ukrainian Academy of Medicine and Dentistry, Protocol No. 188 dated 25.11.2000, where permission to conduct medical and biological research was granted.The study was conducted in accordance with the research plan of the Pediatrics Department no. 2 of Poltava State MedicalUniversity «Optimization of early diagnosis, treatment and prognosis of the most common childhood diseases», state registration number 0122U001876 (years of implementation 2021-2026) and research work – Research Institute of genetic and immunological bases of development of pathology and pharmacogenetics of PDMU «Development of methods of treatment and prevention of development of pulmonary fi brosis by activation of PPAR-gamma receptors», state registration number 0122U201686 (years of implementation 2023-2025).Results. Morning gene expression in healthy children showed statistically higher levels of per1 (0.780 ± 0.070) compared to bmal1 (0.293 ± 0.074; p<0.001), whereas in the evening the level of the latter (0.697 ± 0.130) was signifi cantly higher than per1 (0.370 ± 0.044; p<0.05). Comparing the levels of per1 in this group, the expression of this gene was higher in the morning (0.780 ± 0.070) than in the evening (0.370 ± 0.044; p<0.001), while the expression of bmal1 was higher at 20:00 (0.697 ± 0.130 vs. 0.293 ± 0.074; p<0.05). In contrast, patients with SAR had a signifi cantly higher level of bmal1 gene mRNA expression (1.036±0.161 vs. 0.293±0.074 in healthy children (p<0.05). Examination of gene expression in children with SAR in the evening revealed that bmal1 values showed similar levels of expression in all participants (0.775 ± 0.163 vs. 0.697 ± 0.130; p>0.05), while the mRNA level of the per1 gene was statistically higher in patients with rhinitis (1.293 ± 0.186; p<0.01).Conclusions. The results obtained indicate a dysregulation of the peripheral molecular circadian clock in the buccal epithelium of patients with SAR. The use of the protocol treatment in children with SAR in the evening demonstrated a better restoration of the expression of the positive and negative regulatory link of the molecular circadian clock.