Expression of Cluster of Differentiation 1a-Positive Langerhans Cells in Oral Lichen Planus.

Background/Purpose: Lichen planus is a T-cell-mediated mucocutaneous disorder characterized histopathologically by a band of chronic inflammatory cells in the subepithelial zone and degeneration of basal layer. The present study was aimed to evaluate the distribution and quantitative assessment of cluster of differentiation 1a (CD1a)-positive Langerhans cells (LCs) in oral lichen planus (OLP), thus to determine the role of LCs pertaining to the changes occurring in OLP.

Materials and Methods: Five cases of normal oral mucosa and 20 cases of OLP were immunostained with CD1a antibody; the positive cells were counted manually in the photomicrographs and statistically analyzed using t -test, Mann-Whitney test, and Wilcoxon signed-rank test.

Results: The average percentage of CD1a-positive LCs in normal subjects was 0.9%, and in the OLP cases higher percentage was observed (3.93%). The statistical comparison of these two parameters was significant ( P =0.018). The degree of basal cell degeneration and density of subepithelial infiltrate on statistical comparison with the concentration of CD1a-positive LCs showed significant results.

Conclusion: LCs play a pivotal role in the recruitment of CD4+ and CD8+ cells to the subepithelial region and basal keratinocytes apoptosis. A small number of study subjects, assessment of only CD1a molecule and LCs in the epidermis only were a few of the drawbacks of the study.