Cyclooxygenase-2 Gene-765 single nucleotide polymorphism as a protective factor against periodontitis in Taiwanese.

AIM

Prostaglandin E(2) (PGE(2)) is considered to be an important mediator of tissue destruction in periodontitis. The cyclooxygenase (COX) catalyses the production of PGs. COX-2, which is induced in an inflammatory response, is responsible for PGs synthesis at sites of inflammation. A single nucleotide polymorphism of COX-2(-765) has been shown to alter the expression of the COX-2 gene. The purpose of the present study was to evaluate the association of the COX-2(-765) polymorphism and susceptibility to periodontitis in Taiwanese.

MATERIAL AND METHODS

Eighty-five cases of aggressive periodontitis (AgP), 343 cases of chronic periodontitis (CP) and 153 cases of healthy controls (HC) were recruited for the study. Genotypes of COX-2(-765) were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The distribution of genotypes among groups was compared by logistic regression analyses. The risk for periodontitis associated with genotypes was calculated as the odds ratio (OR).

RESULTS

The prevalence of the GC and CC genotypes was significantly lower in AgP (5%) and in CP (29%) compared with the HC (42%). The ORs for carriage of the -765C allele (GC+CC versus GG) in AgP and CP were 0.068 (95% CI=0.020-0.173, p<0.0001) and 0.571 (95% CI=0.385-0.849, p=0.006), respectively. After adjustment for age, gender and smoking status, the OR was 0.071 (95% CI=0.017-0.219) and 0.552 (95% CI=0.367-0.829) for AgP and CP, respectively.

CONCLUSIONS

The results of the study suggest that the -765G to C polymorphism of the COX-2 gene is associated with a decreased risk for periodontitis in Taiwanese, especially in AgP. However, the biological meaning needs further investigation.