Interleukin-1 and tumor necrosis factor-α gene polymorphisms in Turkish patients with localized aggressive periodontitis

Abstract

Localized aggressive periodontitis (LAgP) is a complex multifactorial periodontal disease to which genetic factors are thought to predispose individuals. Interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) are potent immunomodulators and proinflammatory cytokines that have been implicated in the pathogenesis of autoimmune and infectious diseases and proposed to be risk factors for LAgP. Our aim was to investigate IL-1 alpha (+4845), IL-1 beta (+3954), and TNF-alpha (-308) gene polymorphisms in Turkish LAgP patients. We genotyped 31 LAgP patients and 31 healthy controls for IL-1alpha(+4845), IL-1beta(+3954), and TNF-alpha(-308) using standard PCR amplification followed by restriction enzyme digestion and gel electrophoresis. Higher prevalence of heterozygosity for IL-1alpha(+4845) was found in cases (65%) when compared to controls (35%) (P < 0.05). While homozygous allele 1 of IL-1beta(+3954) was the most frequent genotype in cases (62%), no controls were homozygous for this allele (P < 0.001). Homozygous allele 1 was the most common TNF-alpha genotype in both groups, however no significant difference in TNF-alpha genotypes was found between groups. In conclusion, in this Turkish population, susceptibility to LAgP is increased by heterozygosity for allele 1 of IL-1alpha(+4845) or homozygosity for allele 1 of IL-1beta(R+3954). Moreover, IL-1 gene polymorphisms appear to have a role in susceptibility to LAgP, and the above-mentioned genotypes could be an important risk factor for LAgP in the Turkish population.