Background: Associations between different gene polymorphisms and severe chronic periodontitis have been demonstrated. However, the influence of such genetic variations on the production of related proteins needs to be clarified. The aim of the present investigation was to study the local expression of interleukin (IL)-10 and membrane-bound CD14 (mCD14) in relation to the -1087 IL-10 and -159 CD14 gene polymorphisms in subjects with chronic periodontitis.
Methods: Fifty-three white subjects with generalized and severe chronic periodontitis volunteered. Twenty milliliters of blood was collected by venipuncture from each subject. DNA was isolated, and genotype analysis of the -1087 IL-10 and -159 CD14 gene polymorphisms was performed using polymerase chain reaction and restriction endonuclease mapping techniques. A gingival biopsy from one randomly selected diseased proximal site was also obtained from each subject. The biopsies were embedded, snap frozen, and prepared for immunohistochemical analysis. The inflammatory lesion was identified in the sections, and the proportions of IL-10+ and CD14+ cells were determined.
Results: The proportion of IL-10+ cells in the peripheral area of the periodontitis lesions was significantly larger in subjects with the -1087 IL-10 GG genotype than in subjects with the AG or AA genotype. However, the local expression of the mCD14 receptor did not vary between subjects with different -159 CD14 genotypes.
Conclusions: It is suggested that IL-10 expression in chronic periodontitis lesions is associated with a distinct genotype. The observation adds to our understanding of interactions between genetic and environmental factors in the development of human diseases.