Association of Cytokines, High Sensitive C-Reactive Protein, VEGF and Beta-Defensin-1 Gene Polymorphisms and Their Protein Expressions with Chronic Periodontitis in the Chinese Population

Abstract

Purposes This study aimed at investigating the association between interleukin-6 (IL-6), interleukin-12 (IL-12), C-reactive protein (CRP), vascular endothelial growth factor (VEGF) and β-defensin-1 polymorphisms and the susceptibility to periodontitis in the Chinese population. Methods DNA was extracted from the blood samples of 532 healthy individuals and 122 chronic periodontitis (CP) patients enrolled in the study. The genes encoding IL-6, IL-12, CRP, VEGF and β-defensin-1 were amplified using PCR and digested with restriction enzymes. The protein expression of the abovementioned genes was determined by ELISA. Differences in the allele/genotype frequencies were assessed with the chi-square test. Results The frequencies of the C/C genotypes of IL-6, IL-12, and VEGF were higher in CP patients than healthy controls (66.3% vs 25.9%; 27.8% vs 19.9%; and 64.8% vs 52.1%, respectively). In the patients' group we also recorded frequencies of the A/A genotypes of CRP and VEGF higher than in healthy controls (63.1% vs 58.1% and 64.8% vs 35.2%, respectively). Protein production evaluated by ELISA demonstrated significant differences between CP patients and healthy controls for IL-6, IL-12, CRP, VEGF and β-defensin-1. Conclusions The genotypes of IL-6, IL-12, VEGF and β-defensin-1 and their protein productions were associated with CP in a Chinese population. Genotypes and serum levels of CRP were associated with CP, but alleles frequency showed no difference between CP patients and healthy controls.