Variants in the IL17 pathway genes are associated with atopic asthma and atopy makers in a South American population

Background: Asthma is a complex disorder with multiple phenotypes which can influence its severity and response to treatment. The T_H17 lymphocytes producing IL-17A and IL17-F cytokines, may have a role on asthma inflammation. The aim of our study was to evaluate the association between genetic variants in IL17 pathway genes with asthma and atopy markers.

Materials and methods: Genotyping was performed using a commercial panel in 1245 participants of SCAALA cohort. The study included 91 SNVs in IL-17 pathway genes. Logistic regressions for asthma and atopy markers were performed using PLINK 1.9. In silico analyses were performed using rSNPbase, RegulomeDB, and Gtex portal for in silico gene expression.

Results and discussion: The T allele of rs1974226 in IL17A was positively associated with asthma (OR: 1.37; 95% CI 1.02-1.82). Also, the T allele of rs279548 was positively associated with asthma (OR: 1.30; 95% CI 1.02-1.64), atopy (OR: 1.62; 95% CI 1.05-2.50) and increased expression of the IL17RC in lung and whole blood tissues. The others genetic variants in the IL17 pathways genes were associated with both protection and risk for asthma development as well as with IgE levels.

Conclusion: The genetic variants in IL-17-related genes are associated with the atopic asthma phenotype and IgE production.