title: Progression and mortality of interstitial lung disease in mixed connective tissue disease: a long-term observational nationwide cohort study.
abstract: To assess the prevalence, extent, progression, functional impact and mortality of interstitial lung disease (ILD) in a nationwide unselected MCTD cohort.
  
  
  
  The study cohort included patients with high-resolution CT lung scans available at baseline (n = 135) and at follow-up (n = 119). The extent of disease was expressed as percentage of total lung volume (TLV).
  
  
  
  ILD was present in 41% of MCTD patients at follow-up. Median (interquartile) extent (% of TLV) was 5 (8) at baseline and 7 (17) at follow-up, mean length 6.4 years later. The lung disease progressed in 19% of patients across the observation period. Predictors of ILD progression were elevated anti-RNP titre [hazard ratio (HR) 1.5, 95% CI: 1.1, 2.0; P = 0.008], presence of anti-ro52 antibodies (HR = 3.5, 95% CI: 1.2, 10.2; P = 0.023), absence of arthritis (HR = 0.2, 95% CI: 0.1, 0.6; P = 0.004) and male gender (HR = 4.0, 95% CI: 1.4, 11.5; P = 0.011) after age and baseline disease adjustments. The risk of death increased by 2.9 (95% CI: 1.1, 7.9; P = 0.038) in patients where disease involved ⩾5% of TLV.
  
  
  
  Lung disease extent and progression in MCTD are modest. Yet, the extension continues several years after MCTD diagnosis causing lung function decline and increasing the risk of mortality. The study identified male gender, elevated anti-RNP titre, presence of anti-ro52 antibodies and absence of arthritis as the strongest predictors of ILD progression.
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Norway.|Department of Rheumatology, Dermatology and Infectious Diseases, Oslo University Hospital, Rikshospitalet, Norway.
authors.forename: Silje
authors.initials: S
authors.lastname: Reiseter
authors.affiliation: Department of Rheumatology, Dermatology and Infectious Diseases, Oslo University Hospital, Rikshospitalet, Norway.
authors.forename: Ragnar
authors.initials: R
authors.lastname: Gunnarsson
authors.affiliation: Department of Radiology and Nuclear Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway.
authors.forename: Trond
authors.initials: T
authors.lastname: Mogens Aaløkken
authors.affiliation: Department of Respiratory Medicine, Oslo University Hospital, Norway.
authors.forename: May Brit
authors.initials: MB
authors.lastname: Lund
authors.affiliation: Department of Radiology and Nuclear Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway.
authors.forename: Georg
authors.initials: G
authors.lastname: Mynarek
authors.affiliation: Faculty of Medicine, Biostatistics, University of Oslo, Norway.
authors.forename: Jukka
authors.initials: J
authors.lastname: Corander
authors.affiliation: Department of Rheumatology, Vestre Viken Hospital, Drammen, Norway.
authors.forename: Joanna
authors.initials: J
authors.lastname: Haydon
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Norway.|Department of Rheumatology, Dermatology and Infectious Diseases, Oslo University Hospital, Rikshospitalet, Norway.
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Molberg
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood; D001323:Autoantibodies / Q000097:blood; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000503:physiopathology; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging / Q000209:etiology / Q000276:immunology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000097:blood / Q000150:complications* / Q000276:immunology; D015995:Prevalence; D016016:Proportional Hazards Models; D012261:Ribonucleoproteins / Q000276:immunology; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D012261:Ribonucleoproteins
keywords: anti-ribonucleoprotein antibodies; interstitial lung disease; mixed connective tissue disease; mortality; pulmonary fibrosis