RESUMO
BACKGROUND: Nasal polyposis (NP) is frequently associated with asthma. In this disease, asymptomatic bronchial hyperresponsiveness (BHR) is thought to precede the development of asthma. IL-9 and its receptor have been reported as candidate genes for asthma and to be associated with BHR. OBJECTIVE: The objective of this study was to assess the contribution of 11-9 to the pathogenesis of BHR in NP by comparing the expression of IL-9 and its receptor in bronchial biopsy specimens from three groups of patients with NP: NP without BHR, NP with asymptomatic BHR, and NP with BHR and asthma. METHODS: Bronchial biopsy specimens were examined in terms of cellular infiltration and in terms of expression of IL-9 protein and mRNA as well as of its receptor by using immunohistochemistry and in situ hybridization. RESULTS: Patients with NP with asthma as compared with the two other groups exhibited an increased bronchial infiltration of basophils, eosinophils, and T cells that correlated with the asthma score. The two groups of patients with NP with BHR showed an increased expression in IL-9 protein and mRNA as well as an increase in the expression of IL-9R mRNA at the epithelial level. These modifications were inversely correlated with the airway responsiveness to methacholine, producing a 20% fall in FEV1. There was a close association between IL-9+ cells, IL-5 mRNA expression, and eosinophil infiltration that correlated with each other. CONCLUSIONS: These results suggest an important role for IL-9 in the pathogenesis of BHR and a causal relation between IL-9 and the development of bronchial eosinophilia in asthma.
Assuntos
Interleucina-9/metabolismo , Pólipos Nasais/imunologia , Adulto , Asma/etiologia , Asma/genética , Asma/imunologia , Asma/patologia , Basófilos/imunologia , Basófilos/patologia , Brônquios/imunologia , Brônquios/patologia , Hiper-Reatividade Brônquica/etiologia , Hiper-Reatividade Brônquica/genética , Hiper-Reatividade Brônquica/imunologia , Eosinofilia/etiologia , Eosinofilia/genética , Eosinofilia/imunologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Interleucina-5/genética , Interleucina-9/genética , Masculino , Pessoa de Meia-Idade , Pólipos Nasais/complicações , Pólipos Nasais/genética , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Interleucina/genética , Receptores de Interleucina/metabolismo , Receptores de Interleucina-9 , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
L'asthme peut se presenter sous diverses formes cliniques, non seulement quant a son caractere evolutif, mais aussi quant a son aspect etiologique. Ainsi, la plupart de temps les crises d'asthme... (AU)
