Quantitative morphological analysis of Langerhans cells in healthy and diseased human gingiva

Langerhans cells (LC) are implicated in the initiation and maintenance of i nflammatory periodontal diseases. The purpose of this immunohistological st udy using morphometric and automated image analysis was to determine the mo rphological features of CD1a + LC in healthy and inflammatory gingiva accor ding to their localisation in the upper epithelium or the basal layer. The study was on gingival samples from 11 healthy controls (C), eight patients with gingivitis (G) and 12 patients with severe chronic adult periodontitis (P). The results show that in the basal layer of all experimental groups, the perimeter, surface and equivalent diameter of CD1a + LC were significan tly decreased (P < 0.005) when compared with those in the upper epithelium of the same group. Furthermore, CD1a + LC had become more rounded, reflecte d by a significant increase in form factor (Pe 0.005), when located close t o the epithelial basal membrane. In the upper epithelium of group P, the pe rimeter, surface and equivalent diameter of CD1a + LC were significantly de creased (P < 0.05) and the form factor significantly increased (P < 0.05) w hen compared with the upper epithelium of group C. This work provides evide nce for important morphological variations in CD1a + LC according to their location within the epithelium and the severity of the periodontal disease. The observed morphological changes may reflect a cellular adaptation durin g the epithelial transmigration and could eventually be involved in immune stimulation during periodontitis. (C) 2000 Elsevier Science Ltd. All rights reserved.