Analysis of lymphocyte populations extracted from chronically inflamed human periodontal tissues. I. Identification.

Abstract

The current study was undertaken to characterize the lymphoid cell populations extracted from chronically inflamed periodontal tissues. Tissue was removed from 20 patients undergoing periodontal surgery. All patients had received repeated oral hygiene instruction and root planing prior to the surgery. The excised tissue was cut finely, digested in collagenase for 90 min, and then forced through a stainless steel grid to obtain a single cell suspension. T‐cells were identified by labelling with the monoclonal antibody UCHTI in an immunofluorescence assay. B‐cells were also identified in an immunofluorescence assay by the presence of surface membrane immunoglobulin as well as by labelling with the monoclonal antibodies FMCl, FMC4, and FMC7.Eight patients had 3 mm or less loss of attachment while 12 patients had 5 mm or more loss of attachment. UCHTI+ve cells accounted for almost 50% of the lymphocytes (a mean of 49.3 ± 1.5%), while B‐cells identified by all three of the pan B‐cell markers (Smlg, FMC1, and FMC4) accounted for over 30% of the lymphocytes. There was no statistically significant difference between each group with any of the markers used. The vast majority of B‐cells (81.4%) appeared to carry the maturation antigen identified by the FMC7 antibody. Histologically some fragments of tissues were found to contain large numbers of plasma cells. Other fragments were predominated by lymphocytes, clusters of which had the enzyme profile of T‐cells while in other foci the lymphocytes had the enzyme profile of B‐cells. This finding may reflect the presence of different disease states within the surgical field. Caution should therefore be taken before extrapolating to individual disease sites.