The cytokine level in exhaled breath condensate and cytokine genes polymorphism in children with bronchial asthma

The aim of the research. To assess the levels of cytokines characterising the balance of Th 1 / Th 2 / Th 17 lymphocytes in the expired breath condensate, as well as to study the role of polymorphic variants of these cytokine genes in Krasnoyarsk children with bronchial asthma (BA), depending on the severity and of the disease control level. Material and methods. The study group included 104 BA children and 65 children without bronchopulmonary and allergic diseases in medical history. The diagnosis, severity and disease control level were established in accordance with the recommendations by the GINA working group. Children were divided into groups depending on the severity and BA control level. Research material was considered to be the expired breath condensate (EBC) and DNA from peripheral blood. DNA isolation was carried out by the sorbent method, and genotyping was performed by the real-time PCR method. EBC was collected using the RTube Exhaler Breath Condensate Collector. Th e concentration of cytokines in native EBC samples was determined using the MagPix multiplex immunoassay system. The results were processed using the Statistica soft ware package for Windows 10.0 and Microsoft Excel, 2007. The allele and genotype frequencies were compared with both an online calculator and the χ-square test. An odds ratio (OR) with a 95 % confi dence interval (CI) was carried out to associate the genetic markers with pathology phenotypes. Results. When comparing the genotype and allele frequencies of IL13 rs1800925 polymorphism in BA and control groups, we demonstrated a statistically significant difference for the CC genotype and the T allele. In addition, the prevalence of genotype AA IL17A rs2275913 was found to be higher in the group with controlled ВА, as well as in the group with medium ВА severity. Th ere were no statistically signifi cant diff erences in the polymorphisms IL4 rs2243250, IL5 rs2069812, IFNγ rs2069705 between the patient groups and controls. When determined the concentration of cytokines in EBC, only trace amounts of the analytes under study were revealed. The concentration values for the IL-13, IL-17A and IL-4 cytokines were slightly above the sensitivity threshold of the method and the kit used. IFN-γ and IL-5 were detected only in two patients. Conclusion. No association of polymorphic genes with cytokine concentration levels in the expired breath condensate was found in the study