Wang Dan, Luo Jian, Du Wen, Zhang Lan-Lan, He Li-Xiu, Liu Chun-Tao
Department of Respiratory and Critical Care Medicine, West China School of Medicine and West China Hospital, Sichuan University, Chengdu 610041, China.
J Thorac Dis. 2016 Oct;8(10):2697-2708. doi: 10.21037/jtd.2016.09.36.
Airway structure changes, termed as airway remodeling, are common in asthma patients due to chronic inflammation, which can be assessed by high-resolution computed tomography (HRCT). Considering the controversial conclusions in the correlation of morphologic abnormalities with clinical feature and outcome, we aimed to further specify and evaluate the structural abnormalities of Chinese asthmatics by HRCT.
From August 2012 to February 2015, outpatients with asthma were recruited consecutively in the Asthma Center of West China Hospital, Sichuan University. Standard HRCT and pulmonary function test (PFT) were performed to collect information of bronchial wall thickening, bronchial dilatation, mucus impaction, emphysema, mosaic perfusion, atelectasis, and spirometric parameters. We reported the incidence of each structural abnormality in HRCT and compared it among different asthmatic severities.
A total of 123 asthmatics were enrolled, among which 84 (68.3%) were female and 39 (31.7%) were male. At least one structural abnormality was detected by HRCT in 85.4% asthmatics, and the incidence of bronchial wall thickening, bronchial dilatation, mucus impaction, emphysema, mosaic perfusion, and atelectasis was 57.7%, 51.2%, 22%, 24.4%, 5.7% and 1.6%, respectively. The incidences of bronchial wall thickening, bronchial dilation and emphysema were significantly increased by asthma severity (P<0.05), while incidences of mucus impaction (26/27, 96.30%), mosaic perfusion (6/7, 85.71%) and atelectasis (2/2, 100%) were mainly found in severe asthma. We found a longer asthma history (28.13±18.55 years, P<0.001, P=0.003), older age (51.30±10.70 years, P=0.022, P=0.006) and lower predicted percentage of forced expiratory volume in one second (FEV%) (41.97±15.19, P<0.001, P<0.001) and ratio of forced expiratory volume to forced vital capacity (FEV/FVC) (48.01±9.55, P<0.001, P<0.001) in patients with severe bronchial dilation compared with those in none and mild bronchial dilation. A negative correlation was also found between the extent of bronchial dilation and FEV% as well as FEV/FVC (r=-0.359, P=0.004; r=-0.266, P=0.035, respectively).
The incidences of structural abnormalities detected by HRCT are fairly high in Chinese asthma populations, especially the bronchial wall thickening and bronchial dilation, which are significantly increased in severe asthma, and are potential risk factors of pulmonary function decline in asthmatics.
气道结构改变，即气道重塑，在哮喘患者中因慢性炎症很常见，可通过高分辨率计算机断层扫描（HRCT）进行评估。鉴于形态学异常与临床特征及预后相关性的结论存在争议，我们旨在通过HRCT进一步明确和评估中国哮喘患者的结构异常。
2012年8月至2015年2月，四川大学华西医院哮喘中心连续招募哮喘门诊患者。进行标准HRCT和肺功能测试（PFT）以收集支气管壁增厚、支气管扩张、黏液嵌塞、肺气肿、马赛克灌注、肺不张及肺量计参数等信息。我们报告了HRCT中每种结构异常的发生率，并比较了不同哮喘严重程度患者的发生率。
共纳入123例哮喘患者，其中女性84例（68.3%），男性39例（31.7%）。85.4%的哮喘患者通过HRCT检测到至少一种结构异常，支气管壁增厚、支气管扩张、黏液嵌塞、肺气肿、马赛克灌注和肺不张的发生率分别为57.7%、51.2%、22%、24.4%、5.7%和1.6%。支气管壁增厚、支气管扩张和肺气肿的发生率随哮喘严重程度显著增加（P<0.05），而黏液嵌塞（26/27，96.30%）、马赛克灌注（6/7，85.71%）和肺不张（2/2，100%）的发生率主要见于重度哮喘。我们发现，与无支气管扩张及轻度支气管扩张的患者相比，重度支气管扩张患者的哮喘病史更长（28.13±18.55年，P<0.001，P=0.003）、年龄更大（51.30±10.70岁，P=0.022，P=0.006），且一秒用力呼气容积（FEV%）预测值百分比更低（41.97±15.19，P<0.001，P<0.001）以及用力呼气容积与用力肺活量比值（FEV/FVC）更低（48.01±9.55，P<0.001，P<0.001）。支气管扩张程度与FEV%以及FEV/FVC之间也存在负相关（r=-0.359，P=0.004；r=-0.266，P=0.035）。
在中国哮喘人群中，HRCT检测到的结构异常发生率相当高，尤其是支气管壁增厚和支气管扩张，在重度哮喘中显著增加，是哮喘患者肺功能下降的潜在危险因素。
