The Influence of Interleukin Gene Polymorphism on Expression of Interleukin–1β and Tumor Necrosis Factor–α in Periodontal Tissue and Gingival Crevicular Fluid

Background: A specific composite genotype of the polymorphic interleukin‐1 (IL‐1) gene cluster has recently been associated with severe periodontitis. One polymorphism of the composite periodontitis‐associated genotype (PAG) has been functionally linked with expression of high levels of IL‐1. The purpose of this study was to test whether gingival crevicular fluid (GCF) levels of IL‐1ß and tumor necrosis factor‐alpha (TNFα), and gingival tissue levels of IL‐ 1α, IL‐1β, and TNFα correlate with PAG, and to examine the effec; of conservative periodontal therapy on these levels. Methods: Twenty‐two adults with moderate to advanced periodontal disease were enrolled. Polymerase chain reaction amplification and restriction enzymes were used to identify specific polymorphisms from peripheral blood samples. GCF samples were collected at baseline and 3 weeks following conservative treatment and analyzed by ELISA for IL‐1ß and TNFα. An interproximal gingival biopsy was collected at baseline and follow‐up and analyzed for IL‐1α, IL‐1β, and TNFα by ELISA. Results: The genotyping identified 7 as PAG(+) and 15 as PAG(–). The 2 groups were comparable in terms of existing periodontitis and age. In shallow sites (