comparative study of number and distribution of s+100, cd+4 and cd+8 cells in oral lichen planus and oral lichenoid lesions by immunohistochemical staining

introduction: oral lichen planus (olp) is a common mucocutanous disorder with unknown etiology. while current data suggest that oral lichen planus is a cell-mediated autoimmune disease, it might be associated to s+100, cd+4 and cd+8 cells. because of differential diagnosis of olp and oral lichenoid lesion (oll) is usually difficult this study was designed to compare any probable immunohistochemical differences between these lesions. methods and materials: formalin-fixed, paraffin- embedded tissue sections of 30 oral lichen planus and 60 oral lichenoid lesions were immunohistochemically analyzed for number and distribution of s+100, cd+4 and cd+8 cells. a standard biotin-strerptavidin procedure after antigen retrieval was used. spss-13 software and mann-whitney test were applied in data analysis. results: we could not find any significant differences in number and distribution of cd+4, cd+8 cells and distribution of s+100 cells between two groups but numbers of s100+ cells were higher in epithelium of olp. conclusion: the number of s+100 cells in oral lichen planus was different from lichenoid lesions. in spite of similarities betweem these two groups, it seems they may have different pathogenesis. further studies about mentioned cells with follow up of patients are recommended.