Phenotypic analyses of mononuclear cells recovered from healthy and diseased human periodontal tissues.

Mononuclear cells were recovered from the gingival tissues of normal individuals and from patients with periodontal disease. Lymphocyte phenotypic markers were identified by immunofluorescence after reaction with monoclonal antibodies to T-cell subset markers. The normal tissues exhibited T4/T8 ratios almost identical to those in the peripheral blood. The diseased tissue cell ratios were significantly reduced, in both the adult periodontitis and the juvenile periodontitis groups (P less than 0.01 and P less than 0.02, respectively), indicating alterations in the T-cell subset distribution in these tissues. Each diseased patient showed a much decreased T4/T8 ratio in the gingival lymphocytes when these were compared with the peripheral blood ratio from the same patient. The T4/T8 ratios of the more severe sites were significantly lower than those of the less severe sites in the same disease category. The decreases in subset ratios could be attributed to statistically significant reductions in T4+-lymphocyte recoveries relative to peripheral blood and also to slight relative increases in T8+ lymphocytes. A highly significant (P less than 0.001) correlation between the average probeable periodontal pocket depth and the T4/T8 ratio of each disease category was demonstrated. The relative recoveries of B cells from the various tissues did not differ between diseased and normal tissues. It is suggested that T-cell regulatory expression in gingival tissues is distinct from peripheral blood regulatory expression and that there is a local immunoregulatory imbalance in periodontal disease.