Irreversiblity of Remodeled Features on High-Resolution Computerized Tomography Scans of Asthmatic Patients on Conventional Therapy: A 6-Year Longitudinal Study

Abstract

Airway remodeling can be assessed using high-resolution computerized tomography (HRCT) scanning of both parenchymal-and airway abnormalities in patients with asthma. The aim of this study was to examine structural changes in large and small airways of asthmatic patients using HRCT to determine if remodeling changes had occurred after prolonged use of conventional anti-asthma therapy. HRCT scans were evaluated prospectively for evidence of the following abnormalities: bronchial wall thickening (BWT), bronchiectasis, mucoid impactions, small centrilobular opacities, thick linear opacities, focal hyperlucency, and emphysema. Fifty mild and moderate asthmatics were enrolled in the study group. These abnormalities were re-evaluated in the patients after the passage of 6 years of regular anti-asthma medication. Forty-six of the patients completed the study. The probability of finding at least one abnormality by HRCT investigation was statistically higher in the second scan than in the first (26 patients [56.5%] versus 18 patients [39.1%], p = 0.02]. Irreversibility ratios of abnormalities were 80%, 100%, 75%, 87.7%, 77.8%, and 100% for BWT, bronchiectasis, small centrilobular opacities, focal hyperlucency, thick linear opacity, and emphysema, respectively. The ratios for newly detected structural abnormalities were 25%, 2.5%, 0%, 7.9%, 8.1%, and 0% for BWT, bronchiectasis, small centrilobular opacities, focal hyperlucency, thick linear opacity, and emphysema, respectively. New occurrences and progression in BWT are associated with the duration of asthma affliction (p = 0.03). The results of our study indicate that HRCT remodeling features, once occurring, are irreversible in most of the patients, and new remodeling features also occur despite administering the standard asthma treatment.