Pulmonary manifestations of granulomatosis with polyangiitis and microscopic polyangiitis

ANCA-associated vasculitis (AAV) can have several pulmonary manifestations. There is limited knowledge of the epidemiology and complications of pulmonary manifestations in AAV, despite their association with increased mortality and reduced health-related quality of life.

This study retrospectively analyzed a large, multicentre longitudinal cohort of individuals with AAV followed between 2006 and 2023. Data included diagnosis, demographics, comorbidities, time of disease onset, and pulmonary manifestations of disease. Measures of both disease activity and damage were recorded. Results were summarized across disease sub-types and manifestations.

Data from 1026 individuals were analyzed, including 860 with granulomatosis with polyangiitis (GPA) and 166 with microscopic polyangiitis (MPA). Pulmonary manifestations were seen at any time in the disease course within 81.3% of individuals: 711 (82.7%) with GPA and 123 (74.1%) with MPA. Pulmonary manifestations were reported in 644 (62.7%) at disease onset and 456 (44.4%) individuals during follow-up. Nodules and cavities, diffuse alveolar hemorrhage, and inflammatory infiltrates were the three most common manifestations across the cohort. Nodules and cavities were the most frequent manifestation seen in GPA and diffuse alveolar hemorrhage in MPA. Multiple pulmonary manifestations were seen within 51.9% of individuals with pulmonary manifestations. Pulmonary manifestations were seen in 41.4% of episodes of relapse. 17.4% of those with pulmonary manifestations sustained pulmonary damage from their disease.

Pulmonary manifestations are common in AAV and are associated with permanent damage. Systematic assessments of individuals with AAV for pulmonary involvement will likely improve detection of these manifestations.