IMMUNOHISTOLOGICAL CHARACTERISTICS OF PERIODONTAL LESIONS ASSOCIATED WITH PORPHYROMONAS-GINGIVALIS AND ACTINOBACILLUS-ACTINOMYCETEMCOMITANSINFECTIONS

In this study, various phenotypes of infiltrating cells in the periodo ntium adjacent to pockets harboring Porphyromonas gingivalis and Actin obacillus actinomycetemcomitans were evaluated. Furthermore, the patte rn of Class II antigen expression in the periodontal tissues was deter mined. Eight lesions were associated with the presence of P. gingivali s and 12 with A. actinomycetemcomitans. Predominant cells in the infla mmatory infiltrate were T- and B-cells. In most biopsies T-cells domin ated over B-cells. The proportion of P. gingivalis, but not of A. acti nomycetemcomitans, was positively correlated to the total number of in filtrating cells in the tissue. A. actinomycetemcomitans sites demonst rated somewhat lower proportions of CD3+, CD4+ and CD19+ cells than P. gingivalis sites, However, the tendency of decreasing CD4+/CD8+ ratio with increasing number of A. actinomycetemcomitans indicates a local imbalance in immunoregulation. The frequency of class II antigen expre ssion of both mononuclear and epithelial cells, a sign of immunologica l activation, was generally high.