摘要:The aim of this study was to determine the expression intensity of PCNA and Ki-67 tissue antigens related to pathologically modified oral mucosa in OLR lesions, and to determine the reaction intensity of these antigens in individual clinical forms, i.e. lichen ruber planus (LRP) and lichen ruber erosivus (LRE) comparing the reaction intensity with the inflammation grade and the degree of hyperkeratosis in lesions of 30 patients. Control group included patients (n = 15) with oral leukoplakia simplex. Tissue antigens were observed by immunohistochemical analysis using APAAP and LSAB methods. The reaction on tested tissue antigens was focal positive and of mosaic type. The reaction of the PCNA antigen was intensely high in OLR lesions regardless on the clinical form of the lesion. The reaction intensity positively correlated with the inflammation grade and the degree of hyperkeratosis in lesions. The reaction on Ki-67 tissue antigen ranged from low to moderately high intensity. Intensely high reaction was observed in lesions of lichen ruber erosivus. The reaction positively correlated with the inflammation grade and the degree of hyperkeratosis in lesions. Observed modified reaction of analyzed tissue antigens related with individual clinical forms of OLR might be the indicator of transformed nature of these lesions.