Clinical and Prognostic Significance of p-ANCA Positivity in Idiopathic Pulmonary Fibrosis: A Retrospective Observational Study.

Perinuclear Anti Neutrophil Cytoplasmic Antibody (p-ANCA) is a serological marker of Microscopic Polyangiitis (MPA), a vasculitis associated with lung involvement potentially mimicking Idiopathic Pulmonary Fibrosis (IPF). In this study, we evaluated the role of p-ANCA in predicting clinical evolution and prognosis in a cohort of IPF patients. In this observational, retrospective, case-control study, we compared 18 patients with an IPF diagnosis and p-ANCA positivity with 36 patients with seronegative IPF, matched for age and sex. IPF patients with and without p-ANCA showed similar lung function decline during the follow-up, but IPF p-ANCA+ showed better survival. Half of IPF p-ANCA+ patients were classified as MPA for the development of renal involvement (55%) or skin signs (45%). The progression towards MPA was associated with high levels of Rheumatoid Factor (RF) at baseline. In conclusion, p-ANCA, mainly when associated with RF, could predict the evolution of Usual Interstitial Pneumonia (UIP) towards a definite vasculitis in patients, with a better prognosis compared with IPF. In this view, ANCA testing should be included in the diagnostic workup of UIP patients.

Déclaration de conflit d'intérêts

S.P. reports personal fees from Boehringer Ingelheim, Delphi International srl, and F. Hoffmann-La Roche Ltd. outside the submitted work; G.S. reports personal fees from Boehringer Ingelheim outside the submitted work; C.V. is part of the F. Hoffmann-La Roche Ltd. and Boehringer Ingelheim Scientific Board. He has received consulting fees and/or speaker fees from AstraZeneca, Boehringer Ingelheim, C.F. Hoffmann-La Roche Ltd., and Menarini. A.L., G.M., G.I., L.S., E.F., M.F., and E.G. declare no conflicts of interest.