title: Idiopathic Interstitial Pneumonia Associated With Autoantibodies: A Large Case Series Followed Over 1 Year.
abstract: Some patients with autoimmune characteristics and idiopathic interstitial pneumonia, particularly usual interstitial pneumonia (UIP), do not fit neatly into the category of connective tissue disease-associated interstitial lung disease (CTD-ILD), idiopathic pulmonary fibrosis (IPF), or recently proposed yet to be validated criteria for interstitial pneumonia with autoimmune features (IPAF). Outcomes of these patients are unknown.
  
  
  
  This was a retrospective single-center study. Analyses of variance compared differences in mean change in FVC and diffusion capacity (Dlco) over 1 year among 124 well-defined patients (20 patients with positive autoantibodies with or without symptoms of connective tissue disease [AI-ILD], 15 patients with IPAF, 36 patients with CTD-ILD, and 53 patients with IPF with negative CTD serologies [Lone-IPF]).
  
  
  
  Of the patients, 75% with AI-ILD, 33% with IPAF, and 33% with CTD-ILD had UIP. Initial FVC and Dlco were similarly moderately reduced across groups. Mean change in FVC over 12 months was as follows: -60 mL (IPAF), -110 mL (AI-ILD), -10 mL (CTD-ILD), and -90 mL (Lone-IPF) (P = .52). Mean change in Dlco was as follows: 2.39 mL/mm Hg/min (IPAF), -1.15 mL/mm Hg/min (AI-ILD), -0.27 mL/mm Hg/min (CTD-ILD), and -1.05 mL/mm Hg/min (Lone-IPF) (P < .001). By pattern of disease, the mean change in FVC was as follows: -140 mL (UIP), 10 mL (nonspecific interstitial pneumonia), and 12 mL (unclassifiable/other) (P = .001).
  
  
  
  No clinically significant differences in pulmonary function to distinguish between patients with AI-ILD, IPAF, CTD-ILD, and Lone-IPF were observed after 1 year. Longer periods of follow-up are needed to understand the outcomes of these patients. It is not yet clear whether AI-ILD is a distinct phenotype or a variant of the newly proposed entity IPAF.
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA.
authors.forename: Bridget F
authors.initials: BF
authors.lastname: Collins
authors.affiliation: Institute of Translational Health Sciences, University of Washington Medical Center, Seattle, WA.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Spiekerman
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Shaw
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA.
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Ho
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hayes
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Spada
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Stamato
authors.affiliation: Center for Interstitial Lung Diseases, University of Washington Medical Center, Seattle, WA. Electronic address: graghu@uw.edu.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Raghu
mesh_terms: D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D015551:Autoimmunity / Q000276:immunology; D015331:Cohort Studies; D003240:Connective Tissue Diseases / Q000175:diagnosis / Q000503:physiopathology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology; D017563:Lung Diseases, Interstitial / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020380:Needs Assessment; D012129:Respiratory Function Tests / Q000379:methods; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods; D014861:Washington / Q000453:epidemiology
chemical_list: D001323:Autoantibodies
keywords: autoimmune interstitial lung disease; idiopathic pulmonary fibrosis; interstitial lung disease; interstitial pneumonia with autoimmune features