RESUMO
The oral lichen planus (OLP) is a chronic inflammatory disease, probably autoimmune, with different clinical forms. The most common types are the reticular and the erosive ones. Apoptosis participates in the destruction of basal keratinocytes, but its role in the perpetuation of the subepithelial lymphocytic infiltrates was not yet investigated. To evaluate the involvement of apoptosis in the epithelium and in subepithelial lymphocytic infiltrates, 15 samples of reticular and erosive OLP and 10 samples of healthy oral mucosa were collected and processed histologically. Apoptosis was quantified in the epithelium and in inflammatory cell infiltrates. TUNEL reaction was used to measure apoptosis in the infiltrates. Erosive OLP showed more intense epithelial apoptosis than reticular OLP and controls. In contrast, apoptosis in the inflammatory cell infiltrates was more frequent in reticular than in erosive OLP. Lymphocytes were the predominant cells within the inflammatory cell infiltrates and were more frequent in erosive OLP than in reticular type. These results suggest that different apoptotic levels are involved in the erosive/reticular switch in OLP, determining different clinical presentations. In conclusion, decreased apoptosis in inflammatory infiltrates may contribute to the persistence of T lymphocytes, worsening the attack to the epithelium in erosive OLP.
O líquen plano oral (LPO) é uma doença crônica inflamatória, provavelmente auto-imune, com diferentes formas clínicas. Os tipos mais comuns são o reticular e o erosivo. A apoptose participa da destruição dos ceratinócitos basais, no entanto o seu papel na perpetuação do infiltrado linfocitário subepitelial ainda não foi investigado. Para avaliar o envolvimento da apoptose no epitélio e no infiltrado linfocitário subepitelial, quinze amostras de LPO reticular, quinze de LPO erosivo e dez amostras de mucosa oral saudável foram coletadas e processadas histologicamente. A apoptose foi quantificada no epitélio e nas células do infiltrado inflamatório. A reação de TUNEL foi usada para mensurar a apoptose no infiltrado. A intensidade da apoptose no epitélio mostrou ser maior no LPO erosivo que no LPO reticular e estes foram maiores que no controle. Em contraste, a apoptose nas células do infiltrado inflamatório foi mais freqüente no LPO reticular que no LPO erosivo. Os linfócitos foram as células predominantes dentro do infiltrado inflamatório e foram mais freqüentes no tipo erosivo de LPO que no tipo reticular. Estes resultados sugerem que diferentes níveis de apoptose estão envolvidos no tipo erosivo e reticular de LPO, determinando as diferenças nas apresentações clínicas. Em conclusão, a diminuição da apoptose no infiltrado inflamatório pode contribuir para a persistência dos linfócitos T, piorando o ataque ao epitélio no LPO erosivo.
Assuntos
Humanos , Apoptose/fisiologia , Células Epiteliais/fisiologia , Líquen Plano Bucal/fisiopatologia , Linfócitos/fisiologia , Mucosa Bucal/fisiopatologia , Marcação In Situ das Extremidades CortadasRESUMO
The oral lichen planus (OLP) is a chronic inflammatory disease, probably autoimmune, with different clinical forms. The most common types are the reticular and the erosive ones. Apoptosis participates in the destruction of basal keratinocytes, but its role in the perpetuation of the subepithelial lymphocytic infiltrates was not yet investigated. To evaluate the involvement of apoptosis in the epithelium and in subepithelial lymphocytic infiltrates, 15 samples of reticular and erosive OLP and 10 samples of healthy oral mucosa were collected and processed histologically. Apoptosis was quantified in the epithelium and in inflammatory cell infiltrates. TUNEL reaction was used to measure apoptosis in the infiltrates. Erosive OLP showed more intense epithelial apoptosis than reticular OLP and controls. In contrast, apoptosis in the inflammatory cell infiltrates was more frequent in reticular than in erosive OLP. Lymphocytes were the predominant cells within the inflammatory cell infiltrates and were more frequent in erosive OLP than in reticular type. These results suggest that different apoptotic levels are involved in the erosive/reticular switch in OLP, determining different clinical presentations. In conclusion, decreased apoptosis in inflammatory infiltrates may contribute to the persistence of T lymphocytes, worsening the attack to the epithelium in erosive OLP.