Estudo dos mastócitos entre lesões orais de natureza reativa: granuloma piogênico e hiperplasia fibrosa inflamatória, no humano

Abstract

Introduction: Nonneoplastic proliferative lesions, such as pyogenic granuloma (GP) and inflammatory fibrous hyperplasia (HFI), are due to inflammatory processes. Several cells of the immune system are involved in promoting the inflammatory responses of these reactive lesions. Among them, we highlight the mast cells (MCs), which are smaller in number when compared to the number of lymphocytes and neutrophils. Objective: To identify and compare the presence of MCs in GP and HFI, through tryptase immunoexpression, as well as to investigate if there is relationship between these cells and the intensity of the inflammatory infiltrate present in the studied lesions. Material and methods: Thirty cases of GP and 30 cases of HFI were selected, all fixed in 10% formaldehyde and embedded in paraffin. The material was stained by the Hematoxylin / Eosin (HE) technique and also submitted to the immunoperoxidase method using the Tryptase antibody, clone AA1 (DAKO). Lesions were analyzed for inflammatory infiltrate intensity, being classified as: mild, moderate and intense. And each case was categorized according to the presence of mast cells in the connective tissue: absent, mild, moderate and intense. To verify possible associations between the variables, Pearson's chi-square (X²) and Fisher's exact tests were performed. Results: GP presented a higher prevalence of intense inflammatory infiltrate when compared to HFI. In both lesions analyzed, there was tryptase immunopositivity, but there was no statistically significant difference in the presence of mast cells between GP and HFI. When associating tryptase immunoexpression in mast cells with the intensity of the inflammatory infiltrate, both in HFI and in GP showed absence of statistically significant differences. Conclusion: The intensity of the inflammatory infiltrate is related to the type of lesion studied. However, establishing a more reliable relationship between the presence of mast cells and the inflammatory infiltrate in these entities, and the association between tryptase immunoexpression and the type of lesion studied, it is necessary to perform a quantitative analysis of the mast cells.