Background:Prevalence of anti-neutrophil cytoplasmic antibody (ANCA) in patient with idiopathic pulmonary fibrosis (IPF) ranges from 1 to 35%, mainly anti-MPO. The presence of ANCA positivity seems to be a poorer prognostic factor in patient with IPF, and some of these patients will develop clinical vasculitis (7-23%).Unfortunately, the majority of the available studies on this topic are retrospective and the real natural history of the disease remains poorly understood.Objectives:Aim of the study was to investigate the clinical, serological and radiologic features of patients with interstitial lung disease (ILD) and positivity for anti-MPO, and to evaluate the survival of this population compared with IPF patients.Methods:We retrospectively analysed 30 patients with ILD and anti-MPO antibodies, without diagnosis of vasculitis, from 3 different rheumatology-pulmonology Italian Center.For each patient, clinical, radiologic and serological data were evaluated. Treatments were also collected, both immunosuppressants or antifibrotic agents.Finally, survival of ILD-MPO patients and of 90 unselected idiopathic pulmonary fibrosis (IPF) patients was compared.Results:Thirty patients were enrolled in the study (see table for the characteristics of the patients).Fibrosing pneumonia was described in 73.3% of patients (usual interstitial pneumonia [UIP] in 19 patients), and 10 patients (33.3%) received antifibrotic drugs, all with UIP pattern. Of interest, 7 patients were treated with immunosuppressants (azathioprine, cyclophosphamide, mycophenolate mofetil), independently by the ILD pattern and 21 (70%) low dosage of steroids.After a median period of 23.5 months (range 11-111), 7 patients developed an ANCA associated vasculitis, while other 3 developed other rheumatic diseases.Finally, when compared with IPF, ILD-MPO patients had a better survival (81.2%±0.9 vs 54.7±0.7 for ILD-MPO and IPF, respectively; p=0.045)Conclusion:ILD positive for anti-MPO antibodies are still a not definite condition. We need larger population to identify possible markers for the evolution in an ANCA associated vasculitis, to define the prognosis of disease and the better therapeutic approach.References: :[1]Mohammad AJ, et al. Pulmonary Involvement in Antineutrophil Cytoplasmic Antibodies (ANCA)-associated Vasculitis: The Influence of ANCA Subtype. J Rheumatol. 2017;44:1458-67Table.Serological, clinical and radiological features of anti-MPO + interstitial lung diseaseNumber30Males/female15/15Median age (years + IQR)68 (17)Median follow-up (months + IQR)39.5 (61)Smoke36.70%ILD pattern Usual interstitial pneumonia63.30% Nonspecific interstitial pneumonia16.70% Hipersensitivity pneumonia10% Other fibrosing pneumonia10%Median FVC (% + IQR)83 (23)Median DLCO (% + IQR)53 (28)Clinical features Raynaud’s phenomenon7.70% Sicca syndrome0 Arthralgias20% Arthritis3.40%Serology Antinuclear antibodies30.80% Anti-extractable nuclear antibodies (ENA)8% Anti-SSA4% Rheumatoid factor21.40%Therapy Immusuppressants23.30% Anti-fibrotic drugs33.30%Disclosure of Interests:None declared
Histologic features suggesting connective tissue disease in idiopathic pulmonary fibrosis
