CD-1a immunoexpression in oral lichen planus and oral lichenoid reaction

Oral lichen planus (OLP) is an immunologically mediated mucocutaneous diseases. Langerhans cells (LCs) are antigen presenting cells resident within oral mucosa which, together with intraepithelial lymphocytes, play a role in mucosal defense. The aim of present study was to determine the immunohistochemical expression of LC in oral lichenoid reaction  (OLR) and OLP compared with normal oral mucosa (NOM).

In this cross-sectional study, 61 oral mucosal specimens diagnosed histopathologically as OLP (n=31) and OLR (n=30) and 11 NOM were used to study the immunohistochemical expression of CD1a. The CD1a positive LCs in three regions (basal, suprabasal, and connective tissue) were counted in six randomly selected fields. Data were analyzed using the SPSS 24, T-test, ANOVA, LSD, Games-Howell tests. P<.05 was considered significant.

CD1a expression in OLP and OLR was significantly higher compared to NOM (P<0.001). CD1a expression in OLP was also significantly higher than OLR (P=0.009). There was a statistically significant difference between the three groups in basal, suprabasal and connective tissue regions (P<0.001).  The mean of CD1a positive cells in the basal, suprabasal and connective tissue regions was significantly higher in the OLP group than OLR and NOM. Also, in comparison between OLR and NOM, the OLR group had significantly more CD1a positive cells (P<0.05).

Increasing the number of CD1a in OLP and OLR compared with the NOM indicates the role of LC in the pathogenesis of these diseases.