AUTHOR=Tomassetti Sara , Ravaglia Claudia , Puglisi Silvia , Wells Athol U. , Ryu Jay H. , Bosi Marcello , Dubini Alessandra , Piciucchi Sara , Girelli Francesco , Parronchi Paola , Lavorini Federico , Rosi Elisabetta , Luzzi Valentina , Cerinic Marco Matucci , Poletti Venerino 

TITLE=Clinical implications of interstitial pneumonia with autoimmune features diagnostic criteria in idiopathic pulmonary fibrosis: A case control study

JOURNAL=Frontiers in Medicine

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1087485

DOI=10.3389/fmed.2023.1087485

ISSN=2296-858X

ABSTRACT=<sec><title>Background</title><p>A subgroup of IPF patients can meet IPAF criteria (features suggesting an underlying autoimmune process without fulfilling established criteria for a CTD). This study was aimed to evaluate whether IPAF/IPF patients compared to IPF patients differ in clinical profile, prognosis and disease course.</p></sec><sec><title>Methods</title><p>This is a retrospective, single center, case–control study. We evaluated 360 consecutive IPF patients (Forlì Hospital, between 1/1/2002 and 28/12/2016) and compared characteristics and outcome of IPAF/IPF to IPF.</p></sec><sec><title>Results</title><p>Twenty-two (6%) patients met IPAF criteria. IPAF/IPF patients compared to IPF were <bold>more frequently females</bold> (<italic>N</italic> = 9/22, 40.9% vs. <italic>N</italic> = 68/338, 20.1%, <italic>p</italic> = 0.02), suffered more frequently from gastroesophageal reflux (54.5% vs. 28.4%, <italic>p</italic> = 0.01), and showed a higher prevalence of <bold>arthralgias</bold> (86.4% vs. 4.8%, <italic>p</italic> &lt; 0.0001), <bold>myalgias</bold> (14.3% vs. 0.3%, <italic>p</italic> = 0.001) and <bold>fever</bold> (18.2% vs. 1.9%, <italic>p</italic> = 0.002). The serologic domain was detected in all cases (the most frequent were ANA in 17 and RF in nine cases) and morphologic domain (histology features) was positive in 6 out of 10 lung biopsies (lymphoid aggregates). Only patients with IPAF/IPF evolved to CTD at follow-up (10/22, 45.5%; six rheumatoid arthritis, one Sjögren’s and three scleroderma). The presence of IPAF was a positive prognostic determinant (HR 0.22, 95% CI 0.08–0.61, <italic>p</italic> = 0.003), whereas the isolated presence of circulating autoantibody did not impact prognosis (HR 1.00, 95% CI 0.67–1.49, <italic>p</italic> = 0.99).</p></sec><sec><title>Conclusion</title><p>The presence of IPAF criteria in IPF has a major clinical impact correlating with the risk of evolution to full blown-CTD during follow-up and identifying a subgroup of patients with a better prognosis.</p></sec>