Variation in the composition of gingival inflammatory cell infiltrates

Biopsy specimens were taken at gingivectomy from 18 adult patients undergoing treatment for chronic marginal periodontitis. They were embedded so that the cut surface of the gingiva was parallel to the top of the block to obtain a comprehensive view in a transversal plane of the inflammatory cell infiltrate near the bottom of the pocket. Sections were stained with HES or with toluidine blue for histological description, and acid alpha-naphthyl acetate esterase (ANAE) was used to differentially stain T lymphocytes, plasma cells and monocytes/macrophages. Sections stained with HES showed that the density and size of the cell infiltrates varied along the circumference of a tooth over very short distances and on various surfaces on neighbouring teeth. Differential counts of cells stained for ANAE demonstrated great variation in the composition of the cell infiltrates, particularly along the pocket epithelium. The predominating ANAE positive cell type in this area was T lymphocytes, while in the central connective tissue, plasma cells predominated. There was no systematic covariation between the localization of the gingiva (i.e. mesial, facial, etc.) and the composition of the cell infiltrates. The local variation in the composition of the cellular infiltrate most likely reflects local variability in the noxious substances (i.e. plaque composition) within the periodontal pocket, and in the resulting local inflammatory response.