Association of IL22 gene polymorphism with susceptibility to oral lichen planus and elevated salivary IL-22 lev-els
Objective:To investigate the association between single nucleotide polymorphisms(SNPs)at the interleu-kin-22(IL22)gene loci(rs1026788,rs1179249,and rs2227472)and susceptibility to oral lichen planus(OLP)and salivary IL-22 levels.Methods:Totally 174 whole blood samples from patients with OLP diagnosed by pathology admitted to our dent-al clinic and 206 blood samples from healthy volunteers without a history of oral mucosal diseases from January 2020 to June 2022 were selected.The SNPs distribution frequency of the IL22 gene locus and its correlation with susceptibility to OLP and saliva IL-22 levels were compared between the two groups.Results:The distribution of genotype frequencies at the rs1026788,rs1179249,and rs2227472 loci of the IL22 gene in both groups was consistent with Hardy-Weinberg's law of ge-netic balance.Compared with the ancestral alleles and genotypes,the mutated allele G and genotype GG at rs1026788 or rs2227472 were significantly associated with increased susceptibility to OLP,while the mutated allele A and genotype AA at rs1179249 were associated with decreased susceptibility to OLP(P<0.05).Through the Cochran-Armitage trend test,the risk of OLP increased with the number of mutations(P = 0.01).Subjects carrying at least one of the alleles rs1026788,rs1179249,and rs222742 had an increased susceptibility to OLP(OR=2.096,P=0.016).The saliva IL-22 levels in OLP patients carrying the rs1179249 AC/AA genotype were slightly lower than those of the CC genotype(P=0.024).Conclu-sion:The IL22 loci rs1026788,rs1179249 and rs2227472 may be the genetic marker of OLP susceptibility in Chinese Han population.Moreover,salivary IL-22 levels may be affected by rs1179249.