Comparison of NK-cell (Leu-7+ and Leu-11b+) populations in clinically healthy gingiva, chronic gingivitis and chronic adult periodontitis.

Various investigations have reported the presence of cytotoxic lymphocyte activity in inflammatory periodontal disease. The collective evidence indicates that the inflammatory infiltrates of gingivitis and periodontitis should feature a major component of large granular lymphocytes (NK-cells) possessing cytotoxic potential. Thus, the purpose of this study was to determine and compare, by use of immunohistochemical methods, the numbers of NK-cells in biopsies of clinically healthy gingiva, chronic gingivitis and chronic adult periodontitis and their relationship, if any, to the T- and B-lymphocyte populations. Gingival biopsies were obtained from 8 patients in each of three disease groups selected on the basis of predetermined clinical criteria. Using the avidin-biotin immunoperoxidase technique, four consecutive serial sections from each biopsy specimen were stained with a panel of antihuman monoclonal antibodies for T-lymphocytes (UCHL-1) B-lymphocytes (CD-45R), and NK-cells (Leu-7 and Leu-11b). Analyses of variance yielded a statistically significant main effect for each cell immunophenotype. The Newman-Keuls Sequential Range Test showed statistically significant differences for all but two mean comparisons (p less than 0.01). The comparisons for UCHL-1 and Leu-7 between chronic gingivitis and periodontitis specimens did not demonstrate significance. Although T- and B-lymphocyte populations increased approximately 20 x progressing from healthy to gingivitis to periodontitis specimens, the NK-cell population showed only a 3 x increase which represented 19%, 6.6% and 7% of the total of all positively stained lymphocytes across biopsy groups.