Tanabe Naoya, Sato Susumu, Oguma Tsuyoshi, Shima Hiroshi, Kubo Takeshi, Kozawa Satoshi, Koizumi Koji, Sato Atsuyasu, Togashi Kaori, Matsumoto Hisako, Hirai Toyohiro
Departments of Respiratory Medicine.
Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University.
J Thorac Imaging. 2021 Jul 1;36(4):224-230. doi: 10.1097/RTI.0000000000000568.
Asthma onset before the age of 40 years is associated with distinct clinical manifestations in chronic obstructive pulmonary disease (COPD) patients, but its morphologic features remain unestablished. This study aimed to explore airway morphology in COPD patients with asthma onset before 40 years of age using ultra-high-resolution computed tomography (U-HRCT), which allows a more accurate quantitation of the lumen and the wall in smaller airways than using conventional CT.
Clinical data of 500 consecutive patients undergoing full inspiratory U-HRCT (1024×1024 matrix and 0.25 mm slice thickness) were retrospectively analyzed. COPD patients without asthma, COPD patients with asthma onset at age below or 40 years and above, and non-COPD smoker controls (N=137, 29, 34, and 22, respectively) were enrolled. The length, lumen area (LA), wall thickness and area (WA), and wall area percent (WA%) of the segmental (third-generation) to sub-subsegmental (fifth-generation) bronchus and the low attenuation volume percent (LAV%) were measured.
LA and WA were smaller in the fourth and fifth generation in COPD patients than in non-COPD controls, regardless of the age of asthma onset. LA was smaller and WA% was larger in the fourth-generation and fifth-generation airways in COPD with asthma onset before 40 years than COPD without asthma, whereas WA did not differ between them. In multivariate analyses, asthma onset before 40 years was associated with smaller LA in COPD patients independent of demographics, use of inhaled corticosteroids and long-acting bronchodilators, airflow limitation, and LAV%.
Asthma onset before 40 years of age could be associated with greater lumen narrowing of the airways in COPD.
40岁之前发病的哮喘与慢性阻塞性肺疾病（COPD）患者的不同临床表现相关，但其形态学特征尚未明确。本研究旨在使用超高分辨率计算机断层扫描（U-HRCT）探索40岁之前发病的COPD患者的气道形态，与传统CT相比，U-HRCT能够更准确地定量较小气道的管腔和管壁。
回顾性分析500例接受全吸气U-HRCT（1024×1024矩阵和0.25毫米层厚）的连续患者的临床资料。纳入无哮喘的COPD患者、40岁及以下或40岁及以上发病的哮喘COPD患者以及非COPD吸烟者对照（分别为N = 137、29、34和22）。测量节段性（第三代）至亚亚节段性（第五代）支气管的长度、管腔面积（LA）、壁厚和面积（WA）、壁面积百分比（WA%）以及低衰减体积百分比（LAV%）。
无论哮喘发病年龄如何，COPD患者第四代和第五代的LA和WA均小于非COPD对照。40岁之前发病的哮喘COPD患者第四代和第五代气道的LA较小且WA%较大，而无哮喘的COPD患者之间的WA无差异。在多变量分析中，40岁之前发病的哮喘与COPD患者较小的LA相关，与人口统计学、吸入性糖皮质激素和长效支气管扩张剂的使用、气流受限以及LAV%无关。
40岁之前发病的哮喘可能与COPD患者气道管腔狭窄更严重有关。
