ASSESSMENT OF INTERLEUKIN-6 IN THE PATHOGENESIS OF PERIODONTAL-DISEASE

THIS STUDY WAS PERFORMED TO INVESTIGATE the aspects of interleukin-6 ( IL-6) production in both the gingival tissue and the peripheral blood of patients with periodontal disease and of periodontally healthy subj ects. In addition, IL-6 expression in human gingival tissues was studi ed by reverse transcription-polymerase chain reaction analysis and by immunoperoxidase staining with anti-IL-6 monoclonal antibody. The leve ls of IL-6 in the culture supernatants from peripheral blood mononucle ar cells (PBMC) stimulated with lipopolysaccharide and in serum were e xamined by bioassay. We detected IL-6 mRNA expression in all inflamed gingival tissues (17/17) examined and in 2/4 in healthy gingival tissu es. IL-6 protein was detected mainly in endothelial cells, fibroblasts , and macrophages but not in the area containing T or B cells in the i nflamed gingival tissues, and was not detected at all in healthy gingi val tissues. There was no significant difference between the subjects with periodontal disease and those with healthy gingival tissues eithe r in serum IL-6 levels or in the amount of IL-6 produced by PBMC. Thes e results suggest that non-lymphoid cells in inflamed gingival tissue may contribute to the pathogenesis of periodontal disease via IL-6 pro duction, and that the IL-6 produced in gingival tissue may not reflect the IL-6 levels in peripheral blood. 3.