Department of Veterinary Clinical Sciences, Université de Montréal, Saint-Hyacinthe, Quebec, Canada.
Am J Respir Cell Mol Biol. 2012 Nov;47(5):589-96. doi: 10.1165/rcmb.2011-0363OC. Epub 2012 Jun 21.
Recent studies suggest that airway smooth muscle remodeling is an early event in the course of asthma. Little is known of the effects of long-term antigen avoidance and inhaled corticosteroids on chronically established airway remodeling. We sought to measure the effects of inhaled corticosteroids and antigen avoidance on airway remodeling in the peripheral airways of horses with heaves, a naturally occurring asthma-like disease. Heaves-affected adult horses with ongoing airway inflammation and bronchoconstriction were treated with fluticasone propionate (with and without concurrent antigen avoidance) (n = 6) or with antigen avoidance alone (n = 5). Lung function and bronchoalveolar lavage were performed at multiple time points, and peripheral lung biopsies were collected before and after 6 and 12 months of treatment. Lung function improved more quickly with inhaled corticosteroids, but eventually normalized in both groups. Inflammation was better controlled with antigen avoidance. During the study period, corrected smooth muscle mass decreased from 12.1 ± 2.8 × 10(-3) and 11.3 ± 1.2 × 10(-3) to 8.3 ± 1.4 × 10(-3) and 7.9 ± 1.0 × 10(-3) in the antigen avoidance and fluticasone groups, respectively (P = 0.03). At 6 months, smooth muscle mass was significantly smaller compared with baseline only in the fluticasone-treated animals. The subepithelial collagen area was lower at 12 months than at baseline in both groups. During the study period, airway smooth muscle remodeling decreased by approximately 30% in both groups, although the decrease was faster in horses receiving inhaled corticosteroids. Inhaled corticosteroids may accelerate the reversal of smooth muscle remodeling, even if airway inflammation is better controlled with antigen avoidance.
最近的研究表明，气道平滑肌重塑是哮喘进程中的早期事件。关于长期避免抗原和吸入皮质类固醇对慢性气道重塑的影响知之甚少。我们试图测量吸入皮质类固醇和避免抗原对马气喘（一种自然发生的哮喘样疾病）外周气道重塑的影响。患有气喘的成年马有持续的气道炎症和支气管收缩，用丙酸氟替卡松（有和没有同时避免抗原）（n = 6）或单独避免抗原（n = 5）进行治疗。在多个时间点进行肺功能和支气管肺泡灌洗，并在治疗 6 和 12 个月前后收集外周肺活检。肺功能改善更快与吸入皮质类固醇，但最终在两组都正常化。炎症更好地控制与抗原避免。在研究期间，校正平滑肌质量从 12.1 ± 2.8 × 10（-3）和 11.3 ± 1.2 × 10（-3）减少到 8.3 ± 1.4 × 10（-3）和 7.9 ± 1.0 × 10（-3）在抗原避免和丙酸氟替卡松组，分别（P = 0.03）。在 6 个月时，只有在接受丙酸氟替卡松治疗的动物中，平滑肌质量与基线相比显著较小。在两组中，基底膜下胶原面积在 12 个月时均低于基线。在研究期间，两组的气道平滑肌重塑均减少约 30%，尽管接受吸入皮质类固醇的马减少更快。即使通过避免抗原更好地控制气道炎症，吸入皮质类固醇也可能加速平滑肌重塑的逆转。
