IL-10 G-1082A gene polymorphism and susceptibility to upper respiratory tract infection among endurance athletes.

ABSTRACT

AIM: The aim of this study was to investigate the influence of IL-10 gene polymorphisms on URTI incidence. METHODS: To this end, one hundred healthy elite male athletes participating in the study were classified as either healthy or prone to frequent URTI. Blood samples and DNA isolation, multiplex PCR, and Taqman real-time PCR were carried out. Genomic DNA was extracted from peripheral leukocytes of whole blood samples using the QIAmp DNA Blood Mini Kit (Qiagen, Hilden, Germany). For comparison of the distribution of genotypes between two groups and for estimating odds ratios (OR) for URTI susceptibility in relation to the IL-10 polymorphism, Pearson's chi-square and Logistic regression method were used respectively. RESULTS: The IL-10-1082 genotype distribution differed between athletes with URTI and healthy athletes (χ2=8. 14, P=0.017). The IL-10 high-expression genotype (GG), relative to the other two genotypes combined (AG + AA), was associated with a tendency for an increased likelihood of frequent URTI (OR 4. 63, 95% CI 1. 58-21. 53; P=0. 033). CONCLUSION: In conclusion, findings from this study have identified a potential role of genetic variation in influencing the risk for URTI in athletic populations and SNPs in the IL-10 genes were associated with an altered risk profile. These measures may have a predictive value in the identification of individuals who are more likely to experience recurrent infections when exposed to high physical stress in the areas of athletic endeavor.