Connective tissue disease related fibrotic lung disease: high resolution computed tomographic and pulmonary function indices as prognostic determinants

• Published in: Thorax Vol. 69; no. 3; p. 216
• Main Authors: Walsh, Simon L F, Sverzellati, Nicola, Devaraj, Anand, Keir, Gregory J, Wells, Athol U, Hansell, David M
• Format: Journal Article
• Language: English
• Published: England 01-03-2014
• Subjects: Biopsy; Connective Tissue Diseases - complications; Connective Tissue Diseases - diagnosis; Connective Tissue Diseases - diagnostic imaging; Connective Tissue Diseases - mortality; Connective Tissue Diseases - physiopathology; Humans; Idiopathic Pulmonary Fibrosis - diagnosis; Predictive Value of Tests; Prognosis; Pulmonary Fibrosis - complications; Pulmonary Fibrosis - diagnosis; Pulmonary Fibrosis - diagnostic imaging; Pulmonary Fibrosis - mortality; Pulmonary Fibrosis - physiopathology; Respiratory Function Tests; Sensitivity and Specificity; Severity of Illness Index; Tomography, X-Ray Computed; Connective tissue disease associated lung disease; Interstitial Fibrosis
• ISSN: 1468-3296
• DOI: 10.1136/thoraxjnl-2013-203843

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).
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.
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.
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.