Association of single nucleotide polymorphisms of TLR2, TLR4 and TLR9 with atopic dermatitis

Toll-like receptors (TLRs) are the most studied among all Pattern Recognition Receptors, the main function of which is to initiate innate immune response by recognizing pathogen-associated molecular patterns of various microorganisms on the skin surface. TLR-mediated recognition plays an important role in linking innate and adaptive immunity that ultimately leads to the production of key cytokines, chemokines and antimicrobial peptides. Today, there is growing interest in research on single nucleotide polymorphisms (SNPs) in TLR genes and its influence on susceptibility to inflammatory disease, including atopic dermatitis. The aim of the research was to study the association of the rs5743708 gene polymorphism in the TLR2 gene, the rs4986791 gene polymorphism in the TLR4 gene and the rs352140 gene polymorphism in the TLR9 gene with the risk of developing severe cases of AD. A total of 100 patients with AD were included in the study (38 male and 62 female). The age range was from 18 to 65 years old. All participants were divided into 2 groups according to the SCORAD index (SCORing Atopic Dermatitis). The control group included 72 volunteers over 18 years old. The results of our study showed a statistically significant difference between the moderate AD group and healthy controls in the rs352140 gene polymorphism in the TLR9 gene (Figure 1). The frequency of the GG genotype of SNP rs352140 in TLR9 was 0.169 in the AD group versus 0.329 in the control group (p < 0.05; OR = 0.42; 95% CI = 0.18-0.97).

In conclusion, the results of our study showed that the TLR9 rs352140 gene polymorphism may be linked to an increased risk of atopic dermatitis. Moreover, it was found that the GG genotype of SNP rs352140 in TLR9 can be used as a predictor of the risk of developing moderate AD.

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