Análise imuno-histoquímica de macrófagos M2 e citocinas IL-1β, IL-6 e TNF-α em cistos periodontais apicais

Abstract

The radicular cyst (RC) results from chronic inflammation induced by a bacterial infectious process and reveals the presence of inflammatory cells and cytokines, which are related to the cystic formation and growth. The lymphocytes are the predominant cells in the inflammatory infiltrate of periapical lesions. These cells can differentiate into cell subtypes and produce two types of cellular immune responses: T-helper type 1 (Th1) and T-helper type 2 (Th2). In the same way as lymphocytes, the macrophages can differentiate into cell subtypes. M1 and M2 macrophages play an important role in the targeting of the immune response, due to their ability to promote the differentiation of lymphocytes towards Th1 and Th2 pathways, respectively. The aim of the present study was to evaluate the presence of Th1 response and macrophages M1, through the expression of IL-1 β, TNF-α and IL-6, and Th2 response and the presence of macrophages M2 through the expression of CD163 in cystic capsule of twenty-four cases of RCs. The biomarkers were evaluated by immunohistochemical reactions, dividing the capsule thickness into superficial and deep regions. A greater expression of the cytokines IL-1β, IL-6, TNF-α and M2 macrophages in the superfcial region (p < 0.001) was observed. Absence of correlation was noted among the intensity of inflammation and CD163 in the superficial (p = 0.082, r = 0.362) and deep region (p = 0.415; r = 0.174). There was also a positive correlation among IL-1β and IL-6 and the intensity of inflammation in both regions. The correlation of IL-1β, IL-6 and TNF-α cytokines expression was positive in both regions. In relation to CD163, there was a positive correlation when correlated with TNF-α (p = 0.007, r = 0.537) and IL-6 (p = 0.018, r = 0.478) in the superficial region. Our results demonstrated the presence of the Th1 immune response and M1 macrophages in CPAs through the expression of TNF-α, IL-1β, IL-6 cytokines and Th2 immune response through the presence of M2 macrophages in these lesions. In addition, M2 cells were associated with TNF-α and IL-6 cytokines.