Association of polymorphisms in the tumor necrosis factor-alpha and interleukin-10 genes with oral lichen planus: a study in a chinese cohort with Han ethnicity.

Cytokines have an important role in the pathogenesis and disease progression on oral lichen planus (OLP). The aim of this study is to investigate the impact of gene polymorphisms of T-helper cell subtype Th1/Th2 cytokines, tumor necrosis factor-alpha (TNF-alpha), and interleukin-10 (IL-10) on OLP in a Chinese cohort with Han ethnicity. Three single-nucleotide polymorphisms (SNPs) of the IL-10 gene (IL-10) at positions -1082G/A, -819C/T, and -592C/A and one SNP of the TNF-alpha gene (TNFG) at position -308G/A were analyzed in 151 patients with OLP and 143 healthy controls using polymerase chain reaction with sequence-specific primers (PCR-SSP) method and polymerase chain reaction-restriction fragment length (PCR-RFLP) method. The data revealed that there was no difference between the OLP patients and healthy control groups in frequencies of both TNF-alpha and IL-10 alleles (P = 0.053) and genotypes (P = 0.197). However, the frequencies of TNF-alpha-308A allele (P = 0.013) in patients with erosive OLP were significantly greater than the corresponding values in the control group. Using PHASE software, four haplotypes were deduced from the three IL-10 polymorphisms -1082 G/A, -819 C/T, and -592 C/A, named haplotypes I to IV. The haplotypes IV, which correlated with a lower serum level of IL-10, has a significant association with OLP (P = 0.008). Our study suggests that TNF-alpha and IL-10 gene polymorphisms seem to have some influence on the disease susceptibility and progression of OLP in this Chinese cohort with Han ethnicity.