Increased number of Langerhans cells in oral lichen planus and oral lichenoid lesions

Objective. The aim of this study was to quantify the presence of Langerhans cells (LC) in oral lichen planus (OLP) and oral lichenoid lesions (OLL), comparing them with normal epithelium. Study Design. Thirty-six patients with biopsy-proven OLP or OLL were selected for the study, as well as 23 control subjects free of inflammatory conditions. Immunohistochemical reactions were performed using the streptavidin-biotin peroxidase complex method with CD1a and CD83 primary antibodies. Densities were compared between groups and correlated with microscopic findings. Results. Patients with lichenoid conditions (OLP + OLL) presented higher densities of CD1a(+) cells than the control subjects (P = .03). Higher densities of CD1a were associated with a thinner layer of inflammatory cells (P = .02). Conclusions. This study indicates that OLP and OLL are characterized by the recruitment of LC, which may play a significant role on its pathogenesis. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:661-666)