Zdorovʹe Rebenka (Sep 2020)
The effect of a probiotic containing a strain of Lactobacillus rhamnosus GG on the level of HbD-2 and LL-37 in the secretion of the upper respiratory tract and respiratory morbidity in children with bronchial asthma and allergic rhinitis
Abstract
Background. Today, allergic respiratory diseases in children, including asthma and allergic rhinitis, are a relevant medical and social problem associated with a high risk of disability, a significant reduction in the quality of life of patients and their families, and a significant financial burden on patients and the government. Bronchial asthma and allergic rhinitis often coexist, complicating the course of each other. Children with respiratory allergic diseases are particularly vulnerable to acute respiratory infections. Respiratory viruses, in turn, play an important role in the pathogenesis of bronchial asthma and allergic rhinitis, contributing to the development of diseases and acting as triggers for their exacerbations. One of the possible causes of predisposition to frequent acute respiratory infections in children with allergic pathology of the respiratory system may be a lack of nonspecific factors of mucosal immunity of the respiratory tract — endogenous cationic amphiphilic antimicrobial peptides, in particular, cathelicidin and human defensin. According to many studies, these antimicrobial peptides have antiviral, antimicrobial and immunomodulatory effects. However, nowadays there is insufficient data on the state of production of antimicrobial peptides and their impact on respiratory morbidity in children with allergic diseases. At the same time, some literature sources describe the positive effect of individual probiotic strains, in particular Lactobacillus rhamnosus GG, on the overall resistance to respiratory viral infection and the prevention of atopic diseases. The purpose of our research was to study the concentrations of antimicrobial peptides (HbD-2 and LL-37) in the secretion of the mucous membranes of the upper respiratory tract in children with bronchial asthma and allergic rhinitis, to clarify their role in protection against respiratory viral infection and to estimate the effectiveness of a probiotic preparation containing Lactobacillus rhamnosus GG in the prevention of acute respiratory infections and reduction of the frequency of virus-induced exacerbations of allergic pathology. Materials and methods. We conducted a clinical and laboratory examination of 76 children aged 7 to 17 years, 24 of whom were diagnosed with allergic rhinitis, 28 children — bronchial asthma, and 24 — bronchial asthma and allergic rhinitis. The control group consisted of 20 clinically healthy children of matched age and sex. Research methods also included the analysis of respiratory disease patterns, determination of concentrations of antimicrobial peptides: cathelicidin (LL-37), human β-defensin 2 (HbD-2) in the secretion of the upper respiratory tract by ELISA, and statistical analysis. Results. It was found that children with allergic diseases of the respiratory tract are characterized by a higher frequency of acute respiratory infections (30 %) with more frequent involvement of the lower respiratory tract in the inflammatory process (72 %), which causes a longer duration of disease (95 %) compared to healthy children. The children with allergic rhinitis and bronchial asthma had a significant decrease in the concentrations of antimicrobial peptides in the secretion of the upper respiratory tract compared with the control group. It was found that the level of antimicrobial peptide concentrations in the secretion of the upper respiratory tract is most negatively affected by the allergic inflammation severity, accompanied by a lack of symptom control, and the use of basic therapy and no symptoms have a positive effect. However, even in the presence of complete control of the symptoms of allergic diseases, the levels of antimicrobial peptides were significantly lower than in children of the control group. It was found that there is an inverse relationship between the levels of antimicrobial peptides and the frequency and duration of acute respiratory infections in children with allergic diseases, most pronounced in bronchial asthma. Conclusions. Taking a probiotic drug containing a strain of Lactobacillus rhamnosus GG for a month in addition to the basic therapy of allergic rhinitis and bronchial asthma contributed to a significant increase in levels of HbD-2 (average 27 %) and LL-37 (average 60 %) in secretions of the upper respiratory tract, which was accompanied by a decrease in the frequency of acute respiratory infections by an average of 26 % (including episodes involving the lower respiratory tract), a decrease in the average duration of acute respiratory infections by 22 % over the next year and a decrease in virus-induced exacerbations by 25.7 %.
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