Utility of lung ultrasound in ANCA-associated vasculitis with lung involvement

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are forms of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). AAV most commonly affects the upper and lower respiratory tract as well as the kidneys. The first symptoms are often nonspecific, requiring careful differential diagnosis with infections and malignancies. We analyzed the clinical and radiological data of 38 patients (20 females and 18 males) diagnosed with ANCA-associated vasculitis. Lung involvement was observed in 29 cases. Lung ultrasound (LUS) was performed on 21 patients from the study group and compared to chest CT. For 7 patients the examination was conducted repeatedly. In total, 35 LUS and CT examinations were performed, revealing the following lesions: nodules, infiltrates with and without features of disintegration, caves (n = 17), diffuse alveolar hemorrhage (n = 3), and features of interstitial lung disease (ILD) with pulmonary fibrosis (PF) (n = 11). In 2 cases LUS and CT were negative. In 4 cases LUS was negative, despite a positive CT result. Both in CT and LUS, images of pulmonary lesions were consistent though highly variable. Therefore, further studies are required for a larger group of patients.