Gene Polymorphisms of TNF-α and IL-1β Are Not Associated with Generalized Aggressive Periodontitis in an Iranian Subpopulation

Cytokines play a part in pathogenesis of periodontitis via inflammation phenomenon. Aggressive periodontitis (AgP) is a multifactorial disease resulting in rapid tooth loss due to severe destruction of tooth supporting apparatus. Recently, researchers have focused on genetic susceptibility of periodontitis through investigating the gene variations of cytokines and other components of immune response. In this study we analyzed single nucleotide polymorphism (SNP) of two cytokines in association with AgP in an Iranian-Khorasani population; Interleukin-1 beta (IL-1β) +3954 C/T and Tumor Necrosis Factor alpha (TNF-α) -308 G/A. From arm vein of patients (n=58) and periodontally healthy individuals (n=60) blood sample was obtained and the DNA was extracted. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) procedure was performed to recognize the SNPs. X2 test was used to determine the statistically significant differences between the two groups. The frequency of genotypes and alleles had no significant differences between patients and control groups. The distributions were as follows. IL-1β +3954: CT, CC and TT genotypes in patients were 39.6%, 60.4% and 0.0% and in controls were 41.7%, 50% and 8.3%, respectively. TNF-α -308: GA, GG and AA genotypes in patients were 44.8%, 41.4% and 13.8% and in controls were 46.7%, 50% and 3.3%, respectively. This investigation do not substantiates the role of IL-1β +3954 and TNF-α -308 polymorphisms, separately, as risk determinants for AgP in Iranian population. Further research based on all components of immune response, is needed to corroborate the genetic susceptibility of AgP.