Exploring Human Periapical Lesions: A Histological and Immunohistochemical Analysis of TGF-β1 and CD68 Expression

Abstract Background: Various inflammatory and anti-inflammatory mediators, along with diverse cell types, are involved in the pathogenesis of periapical lesions. This study aimed to assess the immuno-expression of TGF-β1 and CD68 (a macrophage marker), elucidating their roles and potential correlations. Additionally, histological analysis evaluated the intensity of inflammatory infiltrates in periapical lesion samples. Methods: Tissue samples from fifty individuals with periapical lesions (25 radicular cysts (RCs) and 25 periapical granulomas (PGs) were collected, along with control samples from four healthy third molars' dental pulp. Histological examination and inflammatory infiltrate categorization were performed. Immunohistochemical analysis of TGF-β1 and CD68 markers, along with morphometric assessment, were conducted. Statistical analysis included ANOVA testing, Post Hoc Tukey HSD test, and Fisher test, with significance level set at p ≤ 0.05. Results: The control group displayed normal, inflammation-free pulp tissues, while intense inflammation was observed in PGs and RCs (Grade III; 92% and 68%, respectively; p=0.0738) dominated by macrophages, plasma cells, and lymphocytes. Immunohistochemistry showed higher TGF-β1 and CD68 expression in PGs and RCs versus control (P < 0.001). Moreover, PGs exhibited greater TGF-β1 and CD68 expression than RCs (P < 0.001). However, a negative correlation was observed between the 2 markers. Conclusions: This study highlighted varying expressions of TGF-β1 and CD68 in PGs and RCs, indicating their potential roles in lesion pathology. However, a negative correlation between these markers was observed. Moreover, their precise role in periapical tissue repair needs further investigation.