Relative proportions of mononuclear cell types in periodontal lesions analyzed by immunohistochemistry

In this study, we investigated the relative proportions of infiltrating mononuclear inflammatory cells in sections of granulation tissue from periodontitis lesions in both adult periodontitis (AP) and early onset periodontitis (EOP) patients. We utilised a set of cluster of differentiation (CD) antigen-specific monoclonal antibodies to detect different cell types within the tissues. These included anti-CD 20 (B cells), anti-CD 3 (pan T cells) and anti-CD 45RO (memory T cells), anti-CD 4 (helper T cells) anti-CD 8 (suppressor T cells) and anti-CD 68 (monocyte/macrophage). Biopsies of granulation tissue were obtained from 9 patients with adult periodontitis (AP), from 10 patients with early onset periodontitis (EOP) and for comparative purposes, biopsies of gingival tissue from 4 patients with AP. A significantly greater number of T cells (p < 0.05) were observed in EOP and gingival sections than in AP sections. In addition, a greater number of B cells were observed in the granulation tissues than in the gingiva (p < 0.05). The relative numbers of B cells (CD 20). T cells (CD 3) and macrophages (CD 68) were expressed as a percentage of their combined total for each of the patient groups and indicated that the proportion of B lymphocytes was greater in AP sections than in EOP or gingival sections (p < 0.02). The proportion of T cells was lower in the AP periodontitis sections than in the EOP periodontitis sections (p < 0.05). There were no significant differences in the proportion of macrophages between the 3 categories of tissue specimens. The relative ratios of B cells (CD 20) to T cells (CD 3) and B cells (CD 20) to memory T cells (CD 45RO) and macrophages (CD 68) to T cells (CD 3) and memory T cells (CD 45RO) were analyzed and indicated that there was a significant increase in the B to T cell ratio in AP sections compared to EOP and gingival sections (p < 0.02). There was also a significant increase in the macrophage to T cell ratio in AP sections as indicated by CD 68 to CD 3 ratios (p < 0.05). There were no differences regarding the relative proportions of memory T cells or in the ratios of CD 4+ to CD 8+ T cells in the different disease categories. In conclusion, these differences in the relative proportions of B cells, T cells and macrophages may reflect a difference in the immunopathology of AP and EOP.