TLR2, TLR4 and CD86 gene polymorphisms in recurrent aphthous stomatitis.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is an inflammatory disease induced by genetic and environmental factors. Toll-like receptor (TLR) and CD86 are essential components for innate immunity and cellular immune response. We aimed to determine whether inheritance of specific TLR2, TLR4and CD86 gene polymorphisms are associated with RAS. METHODS: Ninety-six patients with RAS and 153 controls were studied. Eight SNPs were genotyped using PCR-RFLP technique; four in TLR2 gene: rs4696480, rs3804100, rs121917864, rs5743708; three in TLR4 gene: rs10759931, rs4986790 rs1927911; and one in CD86 gene rs17281995. Association was assessed by logistic regression analysis. Linkage disequilibrium (LD) was assessed using the Haploview program. RESULTS: Significant increase in inheritance of A allele (OR = 1.6, P = 0.01) and AA genotype (OR = 3.89, P = 0.01) of TLR4 rs10759931 was observed in cases. TLR4rs1927911 C allele and CC genotype were also increased (OR = 1.60 and 2.78 respectively); however, this was not statistically significant (P = 0.02 and 0.03 respectively). TLR2 and CD86 did not show association with RAS. CONCLUSIONS: This is the first study to investigate the association of TLR and CD86 with RAS. We found a significant association between TLR4 rs10759931 polymorphism and RAS. Confirmatory studies in other populations and functional investigations are needed to determine the role of TLR4 in RAS.