STUDY OF EXPRESSION OF HBD-1 AND HBD-2 GENES IN EPITHELIAL CELLS OF MUCOUS UPPER AIRWAY IN NEWBORNS WITH PNEUMONIA DEPENDING ON THE CAUSATIVE AGENT

Β-defensins play an important role in protecting the fetus from infection, so the expression of these antimicrobial peptides in the respiratory tract in newborns is really important. In this regard, we set a task of studying the expression of the HBD-1 and HBD-2 genes in the epithelial cells of the mucous of the upper airway in newborns with pneumonia and in healthy newborns, depending on the causative agent. Also, the polymorphic marker G(-20) A in the DEFB1 gene was associated with infectious pathology of newborns (in particular pneumonia). Methods: The microflora and the factors of congenital immunity on the mucous membranes of the upper airway have been studied in two groups: newborns with ventilator-associated and congenital pneumonia. The biological material was scrapings of epithelial cells of the mucous membrane of the upper airway of newborns and puerperas and blood. Results: It was found that the expression of the HBD-2 gene increases 2.3-fold in children who have an infectious agent, but there are no clinical manifestations of pneumonia. A significant decrease in HBD-2 (3.2 times) in patients with pneumonia caused by K. pneumonia was shown. The frequencies of alleles of the DEFB1 gene in the fetal infection group and in the comparison group: allele G - 0.66, 0.79, allele A - 0.34, 0.21, respectively. The frequencies of the genotypes of the test marker in mothers in the ventilator-associated, congenital pneumonia and the comparison group were as follows: GG - 0.78, 0.58, 0.58; AA is 0, 0.25, 0; AG - 0.22, 0.17, 0.42, respectively. In newborns allele G dominated among alleles (frequency was higher than 0.73 in all groups) and genotype GG (frequency exceeded 0.52). Conclusion: In the course of the study, it was confirmed that β-defensins protect the mucous from infectious agents. The results indicate that the genetic marker G (-20) A of the DEFB1 gene is associated with the risk of developing the child's UTI.