Immunohistochemical study of Langerhans cells in periapical lesions; correlation with inflammatory cell infiltration and epithelial cell proliferation

Aim: The aim of this study is to determine the presence and distribution of Langerhans cells in periapical lesions, and correlate this with inflammatory cell infiltration and epithelial cell proliferation. Material and Methods: Seventy chronic dental periradicular lesions, obtained during periapical surgery from 70 patients, were included in this study, including: 46 granulomas, 18 scar tissue and 6 periradicular cysts. Immunohistochemical staining was performed using the following markers: CD3 to analyze the inflammatory infiltrate, CD1a to determine the presence of Langerhans cells and Ki67 to analyze the epithelial cell proliferation. The CD1a immunostaining density was established following Cincura (2007) criteria, being classified ranging from intense (3), moderate (2), discrete (1) or no (0) immunostaining. CD3 and Ki67 staining was evaluated following the Liapatas et al. scale, as: 0) no cells stained; 1) weak stain or few cells stained (11-25%); 2) moderate staining or some cells stained (26-75%); 3) intense staining or many cells stained (more than 76%). Results: Langerhans cells were found in 32.8% of the periapical lesions being more intense in the epithelialized lesions. CD3 immunohistochemical staining was found in all lesions, but with different values in relation to histological subtypes. Ki67 was positive in all epithelialized lesions, although with a moderate staining. Conclusions: Langerhans cells appeared to be associated with T-lymphocyte infiltration and the proliferative potential of the epithelial tissue in periapical lesions.