A Comparative Immunohistochemical Analysis of Langerhans Cells in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

OBJECTIVES: The present study was to compare the number, distribution and their expression of staining Langerhans cells by CD1a and S-100 antibody with different grades of Oral epithelial dysplasia and Oral squamous cell carcinoma and also to know whether Langerhans cells play any role in local immune response to these diseases. STUDY DESIGN: This study included fifty specimens of paraffin embedded tissue blocks of clinically diagnosed and histopathologically confirmed 25 cases of Oral epithelial dysplasia (10 cases- Mild dysplasia,10 cases –Moderate dysplasia,5 cases –Severe dysplasia) and 25 cases of Oral squamous cell carcinoma (15 cases – Well differentiated,10 cases – Moderately differentiated).Cases selected were clinically and histological diagnosed with back ground of Oral sub mucous fibrosis (OSMF) and histological diagnosis were confirmed by Haematoxylin and Eosin (H & E) stained slides. Control slides are obtained from biopsied mucocele, fibroma, and fibrous epulis cases. RESULTS: The present study shows statistically significant increased in LCs observed from normal mucosa to oral epithelial dysplasia is consistently observed in both S-100 and CD1a positive LCs. However, intra group comparison among the dysplastic groups is found to be statistically insignificant due to fluctuating greater reaction observed in the basal layers of epithelium of S-100 Positive LCs and also its ability to stain cells other than Langerhans cells, but it is statistically significant in CD1a positive LCs. The diminished immune response of LCs in tumour stroma of squamous cell carcinoma is statistically significant in both S-100 and CD1a positive LCs even though CD1a fail to express LCs in advancing grades of carcinoma due to its lack of antigen recognition. CONCLUSION: This is one among the few studies that compares Langerhans cells number, distribution and expression using S-100 and CD1a antibody. The analysis of effective staining of S-100 positive LCs in different grades of dysplasia and carcinoma suggests that sensitivity of S-100 positive LCs found to be greater because of its ability to stain melanocytes other than Langerhans cells.Furthur, this study also concluded that CD1a is a specific marker for Langerhans cells but its specificity is lost when it stains melanocytes in advancing grades of carcinoma. Although, in squamous cell carcinoma irrespective of their differentiation and maturation aspect the mere suppression of Langerhans cells demonstrates significant compromise in tumour immunity.