Abstract
Pulmonary fibrosis is observed in a substantial number of patients with ANCA-associated
vasculitis (AAV), 15% in a recent German series, and may be more frequent in Asian
populations. ANCA are usually of anti-MPO specificity and microscopic polyangiitis
is the most frequent vasculitis. Pulmonary fibrosis may increase the risk of death
in patients with AAV. Treatment for AAV in patients with lung fibrosis should follow
the international guidelines for vasculitis. The role of anti-fibrotic drugs (pirfenidone,
nintedanib) in this condition is still unknown. Pulmonary fibrosis precedes the diagnosis
of AAV or is diagnosed concomitantly in most of the cases. Interestingly, 4% to 35%
of patients with pulmonary fibrosis are ANCA-positive, but only 7% to 23% of the patients
with pulmonary fibrosis and anti-MPO will develop AAV during follow-up. ANCA positivity
may be detected in idiopathic or non idiopathic pulmonary fibrosis. In the absence
of vasculitis, the detection of ANCA does not influence the diagnostic work-up of
patients with lung fibrosis. If an Idiopathic Pulmonary Fibrosis diagnosis is considered,
an anti-fibrotic therapy should be considered, according to local and international
guidelines.
Keywords
idiopathic pulmonary fibrosis - STING - COPA - usual interstitial pneumonia - microscopic
polyangiitis - myeloperoxidase
