Evaluation of interleukin 10, interleukin 1-beta, and tumor necrosis factor-alpha gene polymorphisms in patients with periodontitis and healthy controls

Abstract

Background: Chronic periodontitis (CP) is a prevalent infectious disease caused by an interplay between pathogens and immune responses. Gene polymorphisms are among the factors that affect susceptibility to CP. This study aimed to assess the association between CP and single nucleotide polymorphisms (SNPs) of interleukin-10 (IL-10), interleukin 1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) genes. Methods: A total of 87 patients with CP and 89 healthy controls were included in this study. Venous blood samples were obtained, and DNA was extracted and purified. Segments containing the relevant genes were amplified by polymerase chain reaction (PCR). Electrophoresis was performed after restriction fragment length polymorphism (RFLP) to determine genotype and allele frequencies. Results: The CP group showed significantly different allele and genotype frequencies for three out of five SNPs: IL-10 ─ 592 C/A, IL-10 ─ 819 C/T, and IL-1ß + 3954 C/T (p < 0.05). Additionally, the frequency of the TNF-α ─ 857 AA genotype was significantly lower in patients compared with controls (p = 0.034); however, no significant differences were found in allele frequencies (p > 0.05). Logistic regression analysis revealed that carriers of IL-10 ─ 592 A allele and IL-1ß + 3954 T allele are at higher risk of CP (p < 0.001). Allele and genotype frequencies for TNF-α ─ 308 G/A did not differ significantly between patients and controls (p > 0.05). Conclusions: This study showed specific genotypes of IL-10 ─ 592 C/A, IL-10 ─ 819 C/T, IL-1ß + 3954 C/T, and TNF-α ─ 857 G/A SNPs may be associated with an increased risk of CP development.