Activated lymphocyte subsets in adult periodontitis

The activation state of T and B lymphocytes in the peripheral blood of periodontitis patients may be a reflection of disease activity. We have utilized 2- and 3-color flow cytometric analyses using a new chromophore, peridinin chlorophyll A protein, and conventional dyes, fluorescein isothiocyanate and phycoerythrin, conjugated to monoclonal antibodies against activated lymphocyte surface markers to measure blood lymphocyte subsets from 18 periodontitis patients and 16 periodontally healthy control subjects. Two-color flow cytometric analysis demonstrated that the frequency of CD4+ and CD5+ T cells, CD20+ B cells, and CD16+ NK (natural killer) cells were increased in periodontitis patients. Of particular interest, CD4+ activated "memory" T cells, CD5+ B cells, and CD56+ NK effector cells were increased significantly in periodontitis patients (p less than 0.05). While the relationship of lymphocyte activation to periodontal disease activity remains unclear, there may be potential for using 2- and 3-color flow cytometry to subcategorize periodontitis patients into high- and moderate-risk groups.