T cells and T-cell subsets in periodontal diseases.

Acetone-fixed cryostat gingival tissue sections from marginal gingivitis (MG), juvenile periodontitis (JP), adult periodontitis (AP) patients and clinically healthy subjects (H) were immunohistochemically stained with monoclonal antibodies to aid in identification and quantification of T cells and T-cell subsets in the inflammatory infiltrates. T cells were present in all specimens studied. The number of T cells in the connective tissue (CT) zone of AP was much greater than in any other groups. The amounts of T cells in oral epithelium and sulcular (pocket) epithelium zones of diseased groups were larger than in the healthy group. There was a significant positive correlation between the number of T cells and the percentage of infiltrated connective tissue. While there were no significant differences between the mean ratios of T-helper/T-suppressor cells from diseased and healthy tissues, large individual variance existed in the three diseased groups. The existence of a high or low T4/T8 ratio in inflamed gingiva might be related to an abnormal immunoregulation.