Lung involvement in ANCA-associated vasculitis.

Area of Science:

• Pulmonary Medicine
• Rheumatology
• Immunology

Background:

• Lung involvement is a frequent clinical manifestation in ANCA-associated vasculitides (AAV).
• Key AAV subtypes include granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA).
• Understanding diverse pulmonary presentations is crucial for effective AAV management.

Purpose of the Study:

• To review the five primary patterns of lung involvement in AAV.
• To describe the clinical, radiological, and therapeutic characteristics of each pattern.
• To discuss current challenges and future directions in managing AAV-related lung disease.

Main Methods:

• Comprehensive literature review of pulmonary manifestations in AAV.
• Analysis of clinical, radiological, and therapeutic data for each lung involvement pattern.
• Discussion of subtype-specific prevalence and defining features.

Main Results:

• Five main pulmonary presentations identified: necrotizing granulomatous inflammation, tracheobronchial inflammation, pulmonary capillaritis, interstitial lung disease (ILD), and asthma.
• Necrotizing granulomatous and tracheobronchial inflammation are characteristic of GPA.
• ILD is more common in MPA (especially MPO-ANCA positive), while asthma is typical of EGPA.

Conclusions:

• Pulmonary involvement in AAV is diverse and subtype-specific.
• Current management strategies are evolving, with ongoing research into local therapies, plasma exchange efficacy, antifibrotic agents, and anti-IL-5 therapies.
• Further research is needed to address remaining clinical questions and optimize patient outcomes.