Avaliação imunoistoquímica de CD34 e triptase em cistos odontogênicos radiculares e cistos dentígeros inflamados / Immunohistochemical evaluation of CD34 and tryptase in root odontogenic cysts and inflamed dentigerous cysts

RESUMO

Dentre os cistos odontogênicos comumente encontrados na prática clínica odontológica, os cistos radiculares (CRs) e os cistos dentígeros (CDs) representam conjuntamente os mais frequentes cistos dos ossos gnáticos. Os cistos odontogênicos possuem origem inflamatória ou de desenvolvimento. No entanto, alterações inflamatórias secundárias podem ser vistas nos últimos. Alguns estudos têm identificado os mastócitos nessas lesões císticas e sua possível relação com a angiogênese. Nesta perspectiva, a presente pesquisa objetivou avaliar e comparar a expressão imunoistoquímica do CD34 e da triptase em CDs inflamados e CRs e verificar se os mastócitos influenciam na angiogênese destas lesões. Para tanto, foram selecionados 20 casos de CDs inflamados e 20 casos de CRs para serem submetidos à análise morfológica e imunoistoquímica. A imunomarcação de cada caso foi avaliada de forma quantitativa. Após a identificação das áreas de maior imunorreatividade, foram analisadas a densidade microvascular (DMV), a área microvascular (AMV) e o perímetro microvascular (PMV) mensurados através da imunoexpressão do CD34 e a densidade dos mastócitos (DMC) mensurada por meio da imunoexpressão da triptase, realizadas nas mesmas áreas dos consecutivos campos representativos de cada caso.

ABSTRACT

Among the odontogenic cysts commonly found in dental clinical practice, radicular cysts (RCs) and dentigerous cysts (DCs) together represent the most common cysts of gnathic bones. Odontogenic cysts feature inflammatory or developmental origin. However, secondary inflammatory changes can be seen in the latest. Some studies have identified mast cells in these cystic lesions and its possible relation to angiogenesis. From this perspective, the present study aimed to evaluate and compare the immunohistochemical expression of CD34 and tryptase in inflamed RCs and DCs and to verify if mast cells influence the angiogenesis of these lesions. For this purpose, we selected 20 cases of inflamed DCs and 20 cases of RCs to undergo morphological and immunohistochemical analysis. Immunostaining of each case was evaluated quantitatively. After identifying the areas of greatest immunoreactivity, we analyzed microvessel density (MVD), microvessel area (MVA) and microvascular perimeter (MVP), measured by CD34 immunostaining, and the density of mast cells (DMC), measured by tryptase immunostaining, which were held in the same representative areas of consecutive fields for each case. Statistical analysis was performed using the Mann-Whitney, Chi-square and Fisher's exact tests, and Spearman's correlation (r). Significance level was set at 5% (p < 0.05). The results showed statistically significant differences between the abovementioned cystic lesions regarding DMC evaluation, being higher in CR (p < 0.001). Furthermore, MVD analysis revealed statistically significant differences between cystic lesions (p = 0.007) being greater in CR and also in regard to intensity of the inflammatory infiltrate with a predominance of lesions classified as intense infiltration (p = 0.021). Finally, we observed in cases of inflamed DCs, moderate positive correlation between DMC and MVA (r = 0.660; p = 0.002) and moderate positive correlation between DMC and MVP (r = 0.634; p = 0.003). Given the above, it can be concluded that mast cells participate in different stages of inflammation-associated angiogenesis in RCs and DCs. (AU)