Center for Environmental Medicine, Asthma, and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Clin Exp Allergy. 2011 Dec;41(12):1719-28. doi: 10.1111/j.1365-2222.2011.03814.x. Epub 2011 Jul 5.
Acute exacerbations in allergic asthmatics may lead to impaired ability to clear mucus from the airways, a key factor in asthma morbidity.
The purpose of this study was to determine the effect of inhaled house dust mite challenge on the regional deposition of inhaled particles and mucociliary clearance (MCC) in allergic asthmatics.
We used gamma scintigraphy (inhalation of (99m) Tc -sulphur colloid particles) to measure the regional particle deposition and MCC in allergic asthmatics (n=12) 4 h following an inhaled dust mite allergen challenge (Dermatophagoides farinae extract; PD(max) =fall in forced expiratory volume in 1 s of 10%) for comparison with baseline non-challenge measures.
In responders (n=9 PD(max) dose), lung function returned to pre-challenge values by 3 h but was significantly decreased at 6 and 24 h in three of the responders (i.e. late-phase response) and induced sputum eosinophils were increased at 24 h post-challenge (P<0.05). Responders showed enhanced bronchial airway deposition of inhaled particles (P<0.05) and slowed clearance from the central lung zone (P<0.01) at 4 h post-challenge compared with the baseline (no allergen challenge) that was predicted by the PD(max) allergen concentration (r=-0.70, P<0.05). The decline in lung function at 24 h post-challenge correlated with reduced MCC from the central lung zone (r=-0.78, P<0.02) and PD(max) . Non-responders (n=3) showed no change in lung function, regional deposition or MCC post-challenge vs. baseline.
These data suggest that regional deposition and clearance of inhaled particles may be sensitive for detecting mild airway obstruction associated with early- and late-phase allergen-induced effects on mucus secretions. The study was listed on clinicaltrials.gov (NCT00448851).
变应性哮喘患者的急性加重可能导致气道清除粘液能力受损，这是哮喘发病率的一个关键因素。
本研究旨在确定吸入屋尘螨挑战对变应性哮喘患者吸入颗粒的区域性沉积和粘液清除（MCC）的影响。
我们使用伽马闪烁成像（吸入（99m）Tc-硫胶体颗粒）来测量变应性哮喘患者（n=12）在吸入尘螨过敏原挑战（粉尘螨提取物；PD（max）= 用力呼气量在 1 秒内下降 10%）后 4 小时的区域性颗粒沉积和 MCC，与基线非挑战测量值进行比较。
在反应者（n=9 PD（max）剂量）中，肺功能在 3 小时内恢复到挑战前水平，但在 6 和 24 小时时，有 3 名反应者（即晚期反应）的肺功能显著下降，且诱导痰中的嗜酸性粒细胞在挑战后 24 小时增加（P<0.05）。与基线（无过敏原挑战）相比，反应者在挑战后 4 小时显示出吸入颗粒在支气管气道中的沉积增加（P<0.05），且中央肺区的清除速度减慢（P<0.01），这与 PD（max）过敏原浓度相关（r=-0.70，P<0.05）。挑战后 24 小时的肺功能下降与中央肺区 MCC 的降低相关（r=-0.78，P<0.02）和 PD（max）。非反应者（n=3）在挑战后与基线相比，肺功能、区域性沉积或 MCC 无变化。
这些数据表明，吸入颗粒的区域性沉积和清除可能对检测与早期和晚期过敏原诱导的粘液分泌相关的轻度气道阻塞敏感。该研究已在 clinicaltrials.gov 上注册（NCT00448851）。
