Comparison of morphologic abnormalities in patients with asthma and COPD evaluated by endobronchial optical coherence tomography

S. Zhuquan*^a (Dr), L. Shiyue^a (Prof)

^a The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, CHINA

* py1011xiaoquan@163.com

Objective: To compare the airway structural characteristics between asthma and COPD in transverse and longitudinal section.

Methods: We performed endobronchial optical coherence tomography (EB-OCT) measurement in 19 cases with asthma, 30 with COPD and 22 control subjects. Airway wall thickness and luminal caliber from the 3^rd to 9^th generation of bronchi assessed by EB-OCT were compared, respectively. The clinical characteristics, CT scan and lung function test were collected and analyzed.

Results: There was no significant among-group difference in terms of age, gender and BMI (all P>0.05). Patients with asthma and those with COPD had significant smaller airway caliber (Ai), and greater airway wall thickening (Aw%) compared with control subjects (all P<0.05). Asthmatic patients presented notable medium-sized and small airway narrowing than COPD (Ai 5-6: 4.54±1.33 v.s. 6.00±2.10, P=0.044; Ai7-9: 2.48±0.70 v.s.3.52±1.19, P=0.006). Whereas, the magnitude of small airway remodeling/thickening (Aw%7-9), but not medium-sized airway (from the 3^rd th 6^th generation of bronchi) in patients with asthma was greater than that in COPD (51.06±5.13 v.s. 44.98±8.04, P=0.027).

Conclusion: Asthmatic airway morphological abnormalities involved medium and small airways, while airway remodeling presented more evident in small airways in COPD patients. Patients with asthma had greater magnitude of small airway remodeling than those with COPD, which might be conducive to distinguish among asthma, COPD, and further, asthma and COPD overlap.

Disclosure of funding source(s): none