Association of interleukin-10 gene polymorphisms with severe generalized chronic periodontitis

Background: Interleukin-10 (IL-10), an anti-inflammatory cytokine, plays a role in periodontal disease by inhibiting synthesis of proinflammatory cytokines and stimulating protective antibody production. Genetic polymorphisms in the IL-10 gene might be useful as a marker to diagnose susceptibility to periodontitis. Therefore, the aim of this study was to investigate the association between IL-10 gene polymorphisms and severe generalized chronic periodontitis (CP) in a Turkish population. Methods: Samples of venous blood and DNA were obtained from 75 patients with severe generalized CP and 73 healthy subjects. The IL-10 promoter sequences at positions -597 and -824 were amplified by polymerase chain reaction, and polymorphisms were detected by restriction enzyme cleavage. Genotype and allele frequencies were calculated, and data were analyzed using the chi(2) test. Results: There was a statistically significant difference in frequencies of genotypes (AA/CC + CA: P = 0.00007, odds ratio = 12.37, 95% confidence intervals = 2.74 to 7.77; CC/CA + AA: P = 0.001, odds ratio = 3.05, 95% confidence intervals = 1.47 to 6.33) and alleles (P = 0.0002, odds ratio = 2.61, 95% confidence intervals = 1.52 to 4.51) at position -597 C to A between patients with severe generalized CP and healthy controls, whereas there was no significant difference in genotypes and allele frequencies at position -824 C to T between patients with CP and healthy subjects. Conclusion: Within the limitations of sample selection and number, the IL-10 gene polymorphism at position -597 seems to be associated with severe generalized CP.