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

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.

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.

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.

Within the limitations of sample selection and number, the IL-10 gene polymorphism at position -597 seems to be associated with severe generalized CP.