A genome-wide search for linkage to allergic rhinitis in Danish sib-pair families

Gene polymorphisms of interleukin-10 and transforming growth factor beta in allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) is a polygenic inflammatory disorder of the upper respiratory airway with an increasing prevalence worldwide. Interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β), as two cytokines with pleiotropic effects on both innate and adaptive immunity, play important roles in allergic responses. Therefore, this study was performed to evaluate the associations of five polymorphisms of IL-10 and TGF-β genes with AR.

MATERIALS AND METHODS

Ninety-eight patients with AR along with 140 healthy volunteers with no history of AR and with the same ethnicity of the patients were recruited in this study. Genotyping was done for three polymorphisms in promoter region of IL-10 gene (rs1800896, rs1800871, rs1800872), and two polymorphisms in the exonic region of TGF-β1 gene (rs1982037, rs1800471) using PCR sequence-specific-primers method.

RESULTS

A allele and AA genotype in rs1800896 of IL-10 and TT genotype in rs1982037 in TGF-β were significantly less frequent in the patients than in controls. While the C allele and the CG genotype in rs1800471 in TGF-β1 were associated with a higher susceptibility to AR. C/C and T/C haplotypes (rs1982037, rs1800471) in TGF-β1 gene and A/C/A, A/T/C and G/C/A haplotypes (rs1800896, rs1800871, rs1800872) in IL-10 gene were found with higher frequencies in patients than controls. Patients with CC genotype in rs1800871 in Il-10 had significantly lower levels of IgE.

CONCLUSION

We found that certain genetic variants in IL-10 and TGF-β polymorphisms were associated with susceptibility to AR as well as some clinical parameters in the patients with AR.

Genetics of allergic diseases

Genome-wide association studies (GWAS) have been employed in the field of allergic disease, and significant associations have been published for nearly 100 asthma genes/loci. An outcome of GWAS in allergic disease has been the formation of national and international collaborations leading to consortia meta-analyses, and an appreciation for the specificity of genetic associations to sub-phenotypes of allergic disease. Molecular genetics has undergone a technological revolution, leading to next-generation sequencing strategies that are increasingly employed to hone in on the causal variants associated with allergic diseases. Unmet needs include the inclusion of diverse cohorts and strategies for managing big data.