Association of interleukin-10 gene promoter polymorphism in allergic patients.

Aim: Allergic diseases are increasing alarmingly worldwide affecting >30% of the population, including India. Allergy is the result of interaction of the epitopes on the protein with the immunoglobulin E (IgE). T helper cell-2 cytokines promote allergen-specific IgE antibody and induce eosinophil-dominated inflammatory tissue responses. Interleukin-10 (IL-10), an antiinflammatory cytokine, plays a major role in the development of the allergy. The cytokine gene polymorphism of -592C→A (rs1800872) and -1082G→A (rs1800896) of IL-10 may influence the expression of the protein. Hence, the current study was aimed to evaluate the persistent association between these variants in the susceptibility of the disease.

Methods: The allelic and genotype frequencies corresponding to IL-10 (-592C→A; -1082G→A) were determined in 94 allergic patients and 100 controls. Genomic typing was performed with polymerase chain reaction with sequence-specific primers.

Result: The genotype AA at -592 position (p<0.000; odds ratio [OR] 9.92; 95% confidence interval [CI]=5.06-19.42) and GG at IL-10-1082 position (p<0.04; OR=2.47; 95% CI=1.003-4.96) was associated significantly in patients compared with controls. A considerable frequency of A-A haplotype in the patients and C-A, C-G haplotypes in controls was observed. A highly noteworthy difference was found in diplotype frequencies of A/A-A/A and A/A-G/A in patients and A/C-G/G and A/C-G/A in the controls.

Conclusion: Our results indicate that haplotype and diplotype frequencies of the IL-10 locus may confer susceptibility to allergic patients.