Effect of initial treatment of chronic inflammatory periodontal disease on the frequency of peripheral blood T-lymphocytes specific to periodontopathic bacteria.

Limit dilution analysis (LDA) was used to determine the effect of initial treatment of chronic inflammatory periodontal disease on the frequency of periodontopathic bacteria‐specific T‐cells in peripheral blood. Eleven marginal gingivitis (MG) and 8 adult periodontitis (AP) subjects took part in the study. The proliferative T‐lymphocyte precursor (PTL‐P) frequencies to Porphyromonas gingivalis and Actinomyces viscosus were determined using LDA and Poisson statistics both before and after treatment. Tetanus toxoid was used as a control antigen. Treatment resulted in a significant reduction in clinical disease parameters in both groups. The median peak PTL‐P frequency for P. gingivalis was significantly higher in the AP group compared with the MG group before treatment. This was not the case after treatment nor with A. viscosus. In the MG group the median peak PTL‐P frequency with both P. gingivalis and A. viscosus declined as a result of treatment. Although this decline was not statistically significant it may indicate an antigen‐specific response in this group. In the AP group the median peak PTL‐P frequency with P. gingivalis before treatment was 83.76 × 10 (approximately 1 in 12,000) and after treatment it was 36.17 × 10 (approximately 1 in 28,000). Dose‐response relationships showed at each concentration of organisms/ well this trend for a decline in PTL‐P frequency after treatment, suggesting that any increased responsiveness to this organism in this group may be largely antigen‐specific. However, there was no difference in this group in the median peak PTL‐P frequency with A. viscosus before and after treatment. This, together with the low PTL‐P frequency to A. viscosus, suggests that any increased responsiveness to this organism in this group may be non‐specific. Copyrigh