‘Interleukin-4 gene polymorphism and its relation to periodontal disease in a Brazilian population of African heritage’

Objectives. Host modifying factors, such as genetic predisposition, may increase severity of periodontitis. Genetic polymorphisms in interleukin-4 (IL-4) genes seem to influence host response to microbial challenge. Two IL-4 polymorphisms were found in association with asthma and atopy, and later with aggressive periodontitis in Caucasians. There seems to be a trend for racial differences regarding polymorphisms. Therefore, this study aimed to evaluate if these IL-4 polymorphisms were associated with periodontal disease in a Brazilian population of African heritage. Methods. Sixty patients were divided into two groups: periodontitis group (n=30) and control group (n=30). Blood samples were taken and genomic DNA was amplified by polymerase chain reaction (PCR). Identification of 70 bp repeat polymorphism in intron 2 and in the −590 position of the promoter region was performed through PCR–RFLP and electrophoresis in agarose gel. Results. No significant differences were found in the genotype frequency of the polymorphisms between control and periodontitis group. Chi square test and Mann–Whitney test were used for statistical analysis. Conclusions. We concluded that the studied IL-4 polymorphisms were not related to periodontal disease susceptibility in this African-American Brazilian population.