Density and localization of lymphocytes with natural-killer (NK) cell activity in periodontal biopsy specimens from patients with severe periodontitis.

Natural killer lymphocytes (NKL) in gingival biopsy specimens of 13 patients with advanced periodontitis and 6 normal control subjects have been evaluated by the monoclonal antibody NC 1, anti-B4 and a double immunoenzymatic labeling technique, combining the peroxidase-anti-peroxidase (PAP) method with the alkaline-phosphatase-anti-alkaline-phosphatase (APAAP) technique. Mononuclear cells with NK-activity (NKA) were mainly accumulated in the upper to middle third of the periodontal pocket. The concentration of NC-1-positive cells (CNC) of the baseline biopsy specimens was significantly increased at p = 0.05 compared to the CNC after hygiene training. The statistical difference rose to p = 0.01 following scaling, root planing and curettage therapy. The healthy gingiva of control subjects showed an average of 1-2 NKL, and no statistical difference could be found when compared to the CNC of the biopsy specimens of patients after periodontal therapy. These data support the hypothesis that antibody-dependent cytotoxic immunoreactive lymphocytes in chronic inflammatory periodontal disease can be reduced by scaling and root planing therapy.