Interleukin gene variability and periodontal bacteria in patients with generalized aggressive form of periodontitis

Abstract

Host genetic predispositions to dysregulated immune response can influence the development of the aggressive form of periodontitis (AgP) through susceptibility to oral dysbiosis and subsequent host-microbe interaction. This case-control study aimed to perform a multilocus analysis of functional variants in selected interleukin (IL) genes in patients with the generalized form of AgP in a homogenous population. Twelve polymorphisms in IL-1 gene cluster, IL-6 and its receptor, IL-10, IL-17A, and IL-18 were determined in 91 AgP patients and 210 controls. Analysis of seven selected periodontal bacteria in subgingival sulci/pockets was performed with a commercial DNA-microarray kit in a subgroup of 76 individuals. The pilot in vitro study included stimulation of peripheral blood monocytes (PBMC) from 20 individuals with periodontal bacteria and measurement of IL-10 levels using the Luminex method. Only the unctional polymorphism IL-10–1087 A/G (rs1800896) and specific IL-10 haplotypes were associated with the development of the disease (P < 0.05, Pcorr > 0.05). Four bacterial species occurred more frequently in AgP than in controls (P < 0.01, Pcorr < 0.05). Elevated IL-10 levels were found in AgP patients, carriers of IL-10–1087GG genotype, and PBMCs stimulated by periodontal bacteria (P < 0.05, Pcorr > 0.05). We therefore conclude that a combination of genetic predisposition to the altered expression of IL-10 and the presence of specific periodontal bacteria may contribute to Th1/Th2 balance disruption and AgP development.