Association between human IL-10 gene polymorphisms and serum IL-10 level in patients with food allergy

Single nucleotide polymorphisms (SNPs) of the interleukin-10 (IL-10) gene are associated with allergic diseases in different populations. This study aimed to determine the distribution of two SNPs at -1082A/G and -592A/C (rs1800896 and rs1800872, respectively) in the IL-10 gene promoter of Taiwanese food allergy (FA) patients, and also to compare the serum IL-10 levels between patients with (FA) and controls.

Thirty-seven patients with FA and 52 controls were enrolled, and their peripheral blood was collected for IL-10 SNP genotyping and the corresponding serum IL-10 level of each genotype.

The thirty-seven FA patients had positive food-specific IgE (≥ 0.75kU/L) to more than one food, and the most frequent allergens wereshrimp and crab (56.8% and 35.1%, respectively). The genotype distributions in the FA patients compared to the control group were AA and AG at -1082A/G (86.5% and 13.5% vs. 86.6% and 13.4%, respectively), and AA, AC, and CC at -592A/C (45.9%, 43.3% and 10.8% vs. 38.5%, 48.1% and 13.4%, respectively). Serum IL-10 levels were significantly lower in the FA group than in the control group (p=0.0187), and the IL-10 level of -592A/C of genotype AA was significantly lower than that of the other genotypes (AC+CC) (p=0.007). Patients with AA/AA haplotype homozygotes (10 of 24) had significantly lower serum IL-10 levels than those with other haplotypes.

The two SNPs at -1082A/G and -592A/C of IL-10 were associated with FA in our Taiwanese population, and FA patients with the genotype AA/AA haplotype homozygotes had lower serum IL-10 levels. This suggests that IL-10 might play a critical role in the pathogenesis of FA. We suggest that it may be practicable to evaluate the serum IL-10 levels of FA patients and to predict the possibility of FA if genotypes and haplotypes are checked regularly.