Immunohistochemical Evaluation of CD86 Expression in Ero-sive Oral Lichen Planus

Lichen planus is an inflammatory autoimmune mucocutaneous disease. Stimulation of T cells and antigen-presenting cells (APCs), such as dendritic cells, mediates apoptosis of keratinocytes and basement membrane destruction. The aim of this study was to investigate the expression of one of the immune cell markers (CD86) in erosive oral lichen planus. In this paired analytical cross-sectional study, 22 patients with erosive oral lichen planus were included. Biopsies from oral lesions of these pa-tients were obtained. The surrounding normal marginal mucosa around these lesions served as controls. To visualize CD86-expressing cells, immunohistochemistry (IHC) pro-cesses were used. Data were transferred to SPSS 11.0 software and were analyzed us-ing marginal homogeneity test. This study showed an increased number of CD86-expressing cells in erosive lichen planus lesions, while in normal mucosa, no cells were found to express CD86. Marginal homogeneity test revealed that the difference in positivity and negativity between the groups was significant (P<0.001). A high expression of CD86 in erosive lichen planus lesions shows an increased activation of APCs, while these cells are inactive in normal mucosa.