Peri-implant disease and chronic periodontitis: is interleukin-6 gene promoter polymorphism the common risk factor in a Brazilian population?

• Published in: The International journal of oral and maxillofacial implants Vol. 28; no. 1; p. 35
• Main Authors: Casado, Priscila Ladeira, Villas-Boas, Ricardo, de Mello, Wallace, Duarte, Maria Eugenia Leite, Granjeiro, José Mauro
• Format: Journal Article
• Language: English
• Published: United States 01-01-2013
• Subjects: Adult; Alleles; Brazil; Case-Control Studies; Chi-Square Distribution; Chronic Periodontitis - genetics; Female; Gene Frequency; Genetic Predisposition to Disease - genetics; Genotype; Humans; Interleukin-6 - genetics; Male; Middle Aged; Odds Ratio; Peri-Implantitis - genetics; Polymorphism, Genetic - genetics; Polymorphism, Restriction Fragment Length; Risk Factors; Stomatitis - genetics; Brazil
• ISSN: 1942-4434
• DOI: 10.11607/jomi.2867

To investigate the association between interleukin-6 (IL-6) G174C polymorphism and susceptibility to peri-implant disease (PID) and/or chronic periodontitis (CP), in Brazilian subjects.
A total of 103 Brazilian patients were submitted to peri-implant and periodontal examination. According to their peri-implant characteristics, patients were divided into: group A (healthy, n = 52), group B (peri-implant mucositis, n = 20), and group C (peri-implantitis, n = 31). All patients (n = 103) were also characterized as healthy periodontium patients without CP (HP, n = 60) or CP patients (CP, n = 43). DNA was extracted from buccal cells, and the IL-6 G174C polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism. Differences in the prevalence of genotypes and alleles between healthy and ill patients were analyzed by chi-square test (P < .05), considering PID, CP, and PID+CP.
Results considered the presence of PID and/or CP in all patients. The CC genotype was the least common in all groups. The chi-square test showed no significant correlation between genotypes. However, the odds ratio showed that individuals with GG genotype and allele G were 1.53 and 1.43 times more susceptible to PID, respectively. The risk of presenting CP was increased in patients with GG genotype and allele G 1.35 and 1.24 times, respectively. When both diseases were evaluated together, patients with GG genotypes and allele G were 1.75 and 1.50 times more likely to present PID and CP together. When PID was evaluated without CP, patients with allele G were 2.08 times more susceptible to PID.
The frequency of the genotype IL-6 174GG and allele G was different between healthy and ill groups. Therefore, this genotype may be a common risk factor for both CP and PID in Brazilian populations.