Background: Periodontal disease is a complex pathological process involving a wide spectrum of immunological reactions. The aim of the study was to evaluate the influence of surgical periodontal treatments on peripheral blood lymphocyte subpopulations.

Methods: The study was performed in 40 generally healthy individuals diagnosed with generalized chronic periodontitis and a control group of 36 persons without periodontitis. Peripheral blood lymphocyte subpopulations were examined in both groups. Periodontal treatment was performed, using four different surgical procedures, in the study group. Peripheral blood lymphocyte subpopulations were re-evaluated again after 6 months.

Results: Periodontal treatment resulted in a significant improvement of all measured clinical parameters, regardless of the surgical procedure. When evaluated in the study group as a whole, percentages of all but CD8+ T lymphocyte subpopulations were significantly different from the control group at baseline. Values in both groups after treatment were similar. Correlation analysis suggests a connection between the presence of CD25+ cells and selected clinical parameters of periodontal disease (probing depth and clinical attachment loss).

Conclusions: Statistically significant differences in the percentages of selected lymphocyte subpopulations in the peripheral blood of patients and healthy controls were found. The results suggest a correlation between selected clinical periodontal parameters and percentage of activated cells expressing the interleukin (IL)-2 receptor. Periodontal treatment resulted in significant improvement in the measured clinical and immunological parameters. It seems that the type of surgical treatment has little effect on the normalization of quantitative disturbances of the examined peripheral blood lymphocytes. J Periodontol 2005; 76:1304-1310.