Assessment of Airway Remodeling Using Endobronchial Ultrasound in Asthma-COPD Overlap

Karolina Górka; Iwona Gross-Sondej; Jacek Górka; Tomasz Stachura; Kamil Polok; Natalia Celejewska-Wójcik; Sławomir Mikrut; Anna Andrychiewicz; Krzysztof Sładek; Jerzy Soja

doi:10.2147/JAA.S306421

Assessment of Airway Remodeling Using Endobronchial Ultrasound in Asthma-COPD Overlap

J Asthma Allergy. 2021 Jun 14:14:663-674. doi: 10.2147/JAA.S306421. eCollection 2021.

Authors

Karolina Górka^{1

2}, Iwona Gross-Sondej^{1

2}, Jacek Górka³, Tomasz Stachura^{1

2}, Kamil Polok^{1

3}, Natalia Celejewska-Wójcik^{1

2}, Sławomir Mikrut⁴, Anna Andrychiewicz⁵, Krzysztof Sładek^#^{1

2}, Jerzy Soja^#^{1

2}

Affiliations

¹ Department of Pulmonology and Allergology, University Hospital, Kraków, Poland.
² 2nd Department of Internal Medicine, Jagiellonian University Medical College, Kraków, Poland.
³ Centre for Intensive Care and Perioperative Medicine, Jagiellonian University Medical College, Kraków, Poland.
⁴ Faculty of Mining Surveying and Environmental Engineering, AGH University of Science and Technology, Kraków, Poland.
⁵ Department of Endoscopy, University Hospital, Kraków, Poland.

^# Contributed equally.

Abstract

Purpose: The aim of this study was to evaluate the structural changes of the airways using the endobronchial ultrasound (EBUS) in ACO patients compared to severe asthma and COPD patients.

Patients and methods: The study included 17 patients with ACO, 17 patients with COPD and 33 patients with severe asthma. Detailed clinical data were obtained from all participants. Basic laboratory tests were performed, including measurement of eosinophil counts in blood and serum immunoglobulin E (IgE) concentrations. All patients underwent spirometry and bronchoscopy with EBUS (a 20‑MHz ultrasound probe) to measure the total thicknesses of the bronchial walls and their particular layers in segmental bronchi of the right lower lobe. EBUS allows to distinguish five layers of the bronchial wall. Layer 1 (L₁) and layer 2 (L₂) were analyzed separately, while the outer layers (layers 3-5 [L_3-5]) that correspond to cartilage were assessed together.

Results: In patients with ACO the thicknesses of the L₁ and L₂ layers, which are mainly responsible for remodeling, were significantly greater than in patients with COPD and significantly smaller than in patients with severe asthma (median L₁= 0.17 mm vs 0.16 mm vs 0.18 mm, p<0.001; median L₂= 0.18 mm vs 0.17 mm vs 0.20 mm, p<0.001, respectively). The thicknesses of the total bronchial walls (L₁+L₂+L_3-5) and L_3-5 were significantly smaller in ACO and COPD patients compared to asthma patients (median L₁+L₂+L_3-5= 1.2 mm vs 1.14 mm vs 1.31 mm, p<0.001; median L_3-5= 0.85 mm vs, 0.81 mm vs 0.92 mm, p=0.001, respectively).

Conclusion: The process of structural changes in the airways assessed by EBUS is more advanced in individuals with ACO compared to patients with COPD, and less pronounced compared to patients with severe asthma. It seems that EBUS may provide useful information about differences in airway remodeling between ACO, COPD and severe asthma.

Keywords: airway remodeling; asthma-COPD overlap; bronchial wall layers; endobronchial ultrasound; total bronchial wall.

Grants and funding

This work was supported by the National Science Centre grant (UMO-2015/19/N/NZ5/00268).