Quantitative and species changes in the local microbiota of the upper respiratory tract in allergic rhinitis

BACKGROUND: The role of local microflora in the pathogenesis of allergic rhinitis has not been sufficiently studied; therefore, the study of changes in the nasal microbiome is of interest from a scientific and practical point of view.

AIM: To evaluate changes in the local microbiota of the nasal mucosa in patients with seasonal and year-round allergic rhinitis before and after pharmacological and allergen-specific therapy.

MATERIALS AND METHODS: An observational retrospective single-center case-control study was conducted, which included 182 patients with allergic rhinitis. The groups were randomized according to the diagnosis (seasonal and year-round allergic rhinitis) and the therapy used: basic pharmacotherapy and allergen-specific (sublingual) immunotherapy.

RESULTS: In total, 182 patients completed the study, of which 50 had seasonal allergic rhinitis, 51 had seasonal allergic rhinitis + atopic asthma (aged 7–42 years), and 81 had year-round allergic rhinitis, which included 29 aged 12–54 years and 52 with year-round allergic rhinitis + atopic asthma, aged 12–39 years. Patients with allergic rhinitis were divided into two subgroups: those who received basic therapy to achieve remission and those who received allergen-specific (sublingual) immunotherapy. After basic therapy, the abundance of Staphylococcus aureus in the local microbiota of the upper respiratory tract in patients with seasonal allergic rhinitis decreased by 1.4 times; in the allergen-specific (sublingual) immunotherapy group, its abundance more significantly decreased (3.9 times; p <0.05). In the group with year-round allergic rhinitis, the same pattern was noted. In the group with seasonal allergic rhinitis and year-round allergic rhinitis and the group with both allergen-specific (sublingual) immunotherapy and atopic asthma who received a full course of allergen-specific (sublingual) immunotherapy, the activation index of blood basophils by rSplA-proteinase S. aureus was reduced by 1.2–1.5 compared with the value in those who received basic pharmacotherapy.

CONCLUSION: Patients with allergic rhinitis exhibited quantitative and qualitative significant changes in the microbiome of the upper respiratory tract mucosa, one of the consequences of which is the development of IgE-mediated sensitization to S. aureus products. Allergen-specific immunotherapy for patients with allergic rhinitis leads to decreased colonization of the nasal mucosa with S. aureus and decreased sensitization to rSplA proteinase.