Respiratory Bronchiolitis-Associated Interstitial Lung Disease

• Patients with RB-ILD are typically asymptomatic with some patients experiencing a subclinical decline in lung function³
• In cases where patients are symptomatic, they typically present with mild dyspnea and cough⁷
• Bibasilar end-inspiratory crackles are one of the most common signs of RB-ILD although they are not observed in all patients⁵

• In patients with moderate symptoms there may be a mild to moderate reduction in DL_CO²
• For patients with more severe disease, features of both airway obstruction and restriction may be observed due to concomitant emphysema²

• Features: Ground-glass opacities and centrilobular nodules with bronchial wall thickening^1,6
• Distribution: Diffuse or upper lung predominance⁶

• Smoker's macrophages and absence of lymphocytosis¹

Surgical lung biopsy is not needed if HRCT and bronchoalveolar lavage (BAL) criteria are met.¹

• Pattern of bronchiocentric accumulation of macrophages containing brown particles with mild bronchiolar fibrosis⁶

There is histologic overlap between respiratory bronchiolitis (RB), desquamative interstitial pneumonia (DIP), bronchiolitis and NSIP with RB and DIP representing either end of the spectrum.²

The most common findings on chest HRCT are thickening of the walls of central or peripheral bronchi and ground-glass opacity.²