Respiratory system involvement in ANCA-associated systemic vasculitides

The respiratory system may be involved in all systemic vasculitides (SV), although with a variable frequency. Lung disease is a very common and important feature of the antineutrophil cytoplasmic antibodies (ANCA)-associated SV (AASV), such as Wegener's granulomatosis (WG), Churg-Strauss syndrome (CSS), and microscopic polyangiitis (MPA). The aim of the work is to review the clinical findings, as well as the radiological and pathological features of respiratory system involvement in AASV.

A detailed search via the PubMed index from the National Library of Medicine, covering the period from 1980 to December 2004, was accomplished.

In WG, almost all patients have either upper airway or lower respiratory tract disease. Solitary or multiple nodules and masses are the most common findings on chest radiograph. Asthma is a main symptom of CSS, often preceded by allergic rhinitis, frequently complicated by nasal polyposis and sinusitis. Pulmonary transient and patchy alveolar infiltrates are the most common radiographic findings. In MPA, diffuse alveolar haemorrhage (DAH) due to alveolar capillaritis is the most frequent manifestation of the respiratory involvement, clinically expressing with haemoptysis, respiratory distress and anaemia.

The involvement of the respiratory system is a very common and important feature of AASV. There is substantial overlap in many of the clinical pulmonary features of AASV. In some cases, distinguishing between these diseases on the basis of the clinical features alone is difficult and pathological assessment is needed.