ALDH1 EXPRESSION IN LAMINA PROPRIA OF LICHEN PLANUS, LICHENOID REACTION, LEUCOPLAKIA, AND INFLAMMATORY PROCESSES

Abstract

Objective To evaluate the differences in ALDH1 expression in lamina propria of oral lichen planus (OLP), oral lichenoid reaction (OLR), leucoplakia, and the nonspecific chronic inflammatory process (NCIP). Study Design This study selected 16 samples from each group. The OLP and OLR followed van der Meij and van der Waal criteria, the leucoplakia and NCIP presented subepithelial chronic inflammatory infiltrate. The ALDH1 expression of the samples was investigated by immunohistochemistry. The percentage of positive cells in the selected fields from the lamina propria were evaluated and categorized in 1 to 3. The final score from each sample was defined as the fields' mean score. Only the cells located at the inflammatory infiltrate were considered. Results The OLP presented a higher median expression of ALDH1 in lamina propria (2.00) than RLO (1.25; p=0.012), leucoplakia (1.32; p=0.027), and NCIP (1.15; p=0.005). Moreover, in 4 RLO samples (25.0%), 6 leucoplakia (37.5%), and 5 NCIP (31.25%), all the evaluated fields showed less than 10% of the cells expressing ALDH1. In OLP, this event did not occur. Conclusion the ALDH1 expression in lamina propria was higher in OLP cases, raising the hypothesis that this protein is involved in an autoimmune response. Funding FAPEMIG To evaluate the differences in ALDH1 expression in lamina propria of oral lichen planus (OLP), oral lichenoid reaction (OLR), leucoplakia, and the nonspecific chronic inflammatory process (NCIP). This study selected 16 samples from each group. The OLP and OLR followed van der Meij and van der Waal criteria, the leucoplakia and NCIP presented subepithelial chronic inflammatory infiltrate. The ALDH1 expression of the samples was investigated by immunohistochemistry. The percentage of positive cells in the selected fields from the lamina propria were evaluated and categorized in 1 to 3. The final score from each sample was defined as the fields' mean score. Only the cells located at the inflammatory infiltrate were considered. The OLP presented a higher median expression of ALDH1 in lamina propria (2.00) than RLO (1.25; p=0.012), leucoplakia (1.32; p=0.027), and NCIP (1.15; p=0.005). Moreover, in 4 RLO samples (25.0%), 6 leucoplakia (37.5%), and 5 NCIP (31.25%), all the evaluated fields showed less than 10% of the cells expressing ALDH1. In OLP, this event did not occur. the ALDH1 expression in lamina propria was higher in OLP cases, raising the hypothesis that this protein is involved in an autoimmune response.