Blastogenic responses by lymphocytes from periodontally healthy populations induced by periodontitis-associated bacteria.

Studies of blastogenic responsiveness induced in peripheral blood lymphocytes (PBL) from periodontally healthy subjects by periodontal bacteria have conflicted. This study was undertaken to examine the blastogenic response of periodontally healthy subjects under experimental conditions which provide improved control of laboratory variables. By using cryopreserved PBL the responses of all subjects in an experiment were determined on the same day under identical conditions. The periodontally healthy populations consisted of subjects of the same age range and sex matched to three distinct groups of periodontally diseased subjects (i.e., juvenile (JP), severe (SP), and moderate (MP) periodontitis). The bacterial stimulants tested were chosen on the basis of known association with and isolation from persons fitting the disease classifications. If PBL response differences between periodontally healthy and diseased subjects exist they should be most obvious in response to predominant organisms associated with the disease states. PBL cultures were harvested after a 4 hour pulse with 3H-thymidine on days 4 and 6 of culture. Three separate experiments were conducted comparing one healthy group and one diseased group. In all three experiments subjects in the healthy group responded as frequently as did those in the diseased group, the dose-response distribution was indistinguishable, and the magnitude of the responses was not substantially different between groups. These results suggest nonspecific activation as the major determinant in the blastogenic response, rather than specific sensitization occurring during initiation or progression of periodontitis.