Factor XIIIa+ dendritic cells and S-100 protein+ Langerhans' cells in adult periodontitis

The purpose of this study was to evaluate the presence of factor XIIIa+ dendritic cells and S-100 protein+ Langerhans' cells in the gingival epithelium and connective tissue of periodontal pockets, before and after non-surgical periodontal therapy.

The microbial flora in periodontal pockets provokes complex immune reactions. Dendritic cells play a critical role in primary and secondary immune responses and are considered as antigen-presenting cells. Factor XIIIa positive dendritic cells and S-100 protein positive Langerhans' cells identified by immunoreactivity against factor XIIIa antigen and S-100 protein, respectively, are two distinct subpopulations of dendritic cells.

Fifty-four gingival tissue samples were obtained from periodontal pockets of initial depth 4-5 mm and > or = 6 mm. Each group was subdivided in to three subgroups. The first subgroup consisted of samples taken on baseline day and used as control. The second and third subgroups included those obtained 1 month after plaque and calculus removal, and 1 month after scaling and root planing, respectively, additionally to oral hygiene instructions. The tissues were removed from the palatal gingiva under local anaesthesia during routine periodontal surgery. Immunohistochemical staining with antibodies against factor XIIIa and S-100 protein was performed to identify dendritic cells positive and Langerhans' cells positive, respectively.

Factor XIIIa+ dendritic cell numbers decreased compared to controls after plaque and calculus removal, oral hygiene instructions and scaling and root planing in periodontal pockets of 4-5 mm, but not in those of > or = 6 mm depth. S-100+ Langerhans' cell numbers decreased after periodontal treatment in the periodontal pockets > or = 6 mm.

These results may reflect a tendency for reduction of these two distinctive subpopulations of dendritic cells after non-surgical periodontal therapy.