Interleukin 1 beta-secreting cells in inflamed gingival tissue of adult periodontitis patients

Interleukin 1 beta (IL-1 beta) is a cytokine with a wide range of biologica l activities. It is produced by various cell types including macrophages, f ibroblasts, and neutrophils. The inflammatory responses mediated by IL-1 be ta play an important role in periodontal tissue destruction. The purposes o f this study were: (1) to determine the location of IL-1 beta in inflamed h uman gingival tissues by the immunofluorescence method; and (2) to correlat e this location to the concomitant presence of macrophage or neutrophils by immunohistochemistry. Five patients with moderate to advanced adult period ontitis receiving periodontal phase I therapy were included in this study. One month after phase I therapy, 15 sites with a probing pocket depth 25 mm and gingivitis index greater than or equal to 1 were arranged for modified Widman flap operation. Another three sites with a probing pocket depth les s than or equal to 3 mm and gingivitis indes=0 from two gingival healthy su bjects who received crown-lengthening operation were also chosen as a contr ol group. After clinical parameter recording, a biopsy of gingival tissues from all sites was obtained during the operation. The gingival specimens we re frozen immediately for further immunofluorescent examination of IL-1 bet a and immunocytochemical localization of macrophages and neutrophils. The m acrophages were found to be widely distributed in inflamed gingival connect ive tissue and near-by pocket wall tissue. The neutrophils were aggregated in pocket wall and were sparsely seen in connective tissue. IL-1 beta immun ofluorescent reaction was detected with high intensity in gingival connecti ve tissue especially at the subepithelial region. IL-1 beta immunofluoresce nce with low intensity was only occasionally seen in pocket wall tissue. Th ere was a strong association between the presence of macrophages and IL-1 b eta expression. Similarly, there was a positive association between neutrop hils and IL-1 beta immunofluorecence. These results suggested that large am ounts of IL-1 beta are present in inflamed gingival tissues, and that both macrophages and neutrophils are predominate in IL-1 beta production in infl amed gingival tissues. (C) 1999 Academic Press.