Influence of cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms in periodontitis

Abstract

Aim: Persistent host inflammatory immune response against the pathogens results in the destruction of periodontal tissues. Cytotoxic T lymphocyte antigen 4 (CTLA-4) is a particularly important molecule in down-regulating T-cell expansion and cytokine production. This study aimed to assess three functional SNPs within CTLA-4 gene, -1722 T/C, -318 C/T, and +49 A/G in patients with aggressive or chronic periodontitis.

Materials and methods: A total of 197 patients with periodontitis (71 aggressive and 126 chronic periodontitis) and 218 healthy controls were recruited. All samples were genotyped for CTLA-4 gene polymorphisms by polymerase chain reaction-amplification refractory mutation system (PCR-ARMS).

Results: The allelic and genotype frequencies of only +49 A/G SNP were more prominence in patients with chronic periodontitis (CP) than that controls (0.0005 and 0.001, respectively). Multivariate logistic regression analysis was demonstrated that homozygosity in +49 G/G had profoundly increased susceptibility for CP, OR=3.7 (95% CI; 1.6-8.5, P=0.001). In addition, comparison of CTLA-4 SNPs between patients with CP and aggressive periodontitis (AgP) revealed that heterozygosity in -1722 T/C polymorphism of CTLA-4 gene had a significantly higher risk for CP compared with AgP with a calculated odds ratio of 2.18 (95% CI; 1.17-4.06, P=0.01).

Conclusion: These results suggest that CTLA-4 gene variants might be associated to susceptibility to specific form of periodontitis and participate in the CP development.