title: Connective tissue disease related fibrotic lung disease: high resolution computed tomographic and pulmonary function indices as prognostic determinants.
abstract: OBJECTIVE
  To determine high resolution computed tomography (HRCT) patterns and pulmonary function indices which are associated with increased mortality in patients with connective tissue disease related fibrotic lung disease (CTD-FLD).
  
  
  METHODS
  HRCTs from 168 patients with CTD-FLD were scored by 2 observers for a variety of HRCT patterns and traction bronchiectasis. A radiological diagnosis of usual interstitial pneumonia (UIP), fibrotic non-specific interstitial pneumonia (NSIP) or indeterminate was also assigned. Using Cox regression analysis, associations with mortality were identified. Honeycombing and traction bronchiectasis scores were converted to binary absence/presence scores and also tested. A subgroup analysis of patients with biopsy material (n=51) was performed by classifying patients according to radiological and histopathological diagnoses, as concordant UIP, discordant UIP and fibrotic NSIP. The prognostic separation of this classification was also evaluated.
  
  
  RESULTS
  Severity of traction bronchiectasis (HR 1.10, p=0.001, 95% CIs 1.04 to 1.17), increasing extent of honeycombing (HR 1.08, p=0.021, 95% CI 1.03 to 1.13) and reduction in DLco (HR 0.97, p=0.013, 95% CI 0.95 to 0.99) were independently associated with increased mortality. Interobserver agreement and prognostic strength were higher for binary traction bronchiectasis scores (weighted κ (κw)=0.69, HR 4.00, p=0.001, 95%CI 1.19 to 13.38), than binary honeycombing scores (κw=0.50, HR 2.87, p=0.022, 95% CI 1.53 to 5.43). The radiological-histopathological classification was strongly associated with increased mortality (HR 2.74, p<0.001, 95% CI 1.57 to 4.77) and patients with discordant UIP had a better prognosis than concordant UIP but worse prognosis than fibrotic NSIP.
  
  
  CONCLUSIONS
  Severity of traction bronchiectasis, extent of honeycombing and DLco are strongly associated with mortality in CTD-FLD. Interobserver agreement for traction bronchiectasis is higher than for honeycombing. In CTD-FLD, radiological diagnosis has survival implications in biopsy proven UIP.
authors.affiliation: Department of Radiology, Royal Brompton Hospital, , London, UK.
authors.forename: Simon L F
authors.initials: SL
authors.lastname: Walsh
authors.forename: Nicola
authors.initials: N
authors.lastname: Sverzellati
authors.forename: Anand
authors.initials: A
authors.lastname: Devaraj
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Keir
authors.forename: Athol U
authors.initials: AU
authors.lastname: Wells
authors.forename: David M
authors.initials: DM
authors.lastname: Hansell
mesh_terms: D001706:Biopsy; D003240:Connective Tissue Diseases / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis; D011237:Predictive Value of Tests; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed
keywords: Connective tissue disease associated lung disease; Interstitial Fibrosis