Abstract

Abstract BACKGROUND:The clinical manifestations of r bronchial remodelling in asthma and the potential impact of this process on lung function remain unclear..ObjectivesWe aimed to determine whether the presence of pathological features of airway remodelling in asthma patients was associated with steroid responsiveness in the short term..MethodsSixty-three consecutive severe asthma patients with chronic airflow impairment (post bronchodilator FEV1s < 80% predicted values) were recruited, clinically characterised, and had an initial bronchoscopy where endobronchial biopsy and bronchoalveolar lavage were i performed. BAL cellular content was reported and Reticular Basement Membrane (RBM) thickness was measured by validated repeated measures. Patients were then treated with directly administered intravenous one mg/kg/day of methyl prednisone for 10 days. A threshold of 15% FEV1s improvement was used to discriminate responsive (group 1) and refractory patients (group 2).ResultsThirty-eight patients had a steroid responsiveness greater than 15% (group 1) and a thinner RBM at the biopsy level (5.78 ± 2.0 vs. 7.60 ± 2.2 μm, p .001) compared to non-steroid responsive group 2 patients as defined. No long-term treatment with oral steroids and increased RBM thickness were the best predictors for being unresponsive. The associated ROC curve indicated that RBM thickness could predict steroid responsiveness below 15% with an AUC of 0.747 (p 0.0002) at a threshold of 7 μm.Conclusion and clinical relevanceFeatures of airway remodelling are associated with limited short-term steroid responsiveness in severe asthma.