Health-related quality of life in idiopathic pulmonary fibrosis: Data from the Australian IPF Registry.

BACKGROUND AND OBJECTIVE: Studies analysing the effect of worsening pulmonary physiological impairment in idiopathic pulmonary fibrosis (IPF) with respect to quality of life have been limited to single centres or highly selected trial populations. The aim of this study was to determine the principal determinants of baseline and longitudinal health-related quality of life (HRQoL) in a large unselected IPF population. METHODS: We used the Australian IPF Registry to examine the relationship between HRQoL, measured using the St George Respiratory Questionnaire (SGRQ), and demographic features, physiological features, co-morbidities and symptoms. Linear regression analysis was performed to identify predictors of baseline HRQoL, linear mixed model analysis to determine the effect of time and forced vital capacity (FVC) on SGRQ and Cox proportional hazards regression to examine the relationship between HRQoL and all-cause mortality. RESULTS: Baseline data from 516 patients were available (347 males; mean (SD) age: 71.3 ± 8.6 years). Univariate analysis showed significant associations between HRQoL and demographic, clinical and physiological features. However, multivariate analysis demonstrated independent associations only between SGRQ and dyspnoea (University of California San Diego Shortness of Breathlessness Questionnaire (UCSD-SOBQ); R2 = 0.71, P < 0.0001), cough severity (visual analogue scale; R2 = 0.06, P < 0.0001) and depression (Hospital Anxiety and Depression Scale; R2 = 0.04, P < 0.0001). Linear mixed-effects modelling of combined baseline and longitudinal data confirmed these associations, as well as for FVC% predicted (P = 0.005). Multivariate Cox proportionate-proportional hazards regression analysis demonstrated no association between HRQoL and risk of mortality. CONCLUSION: Cough, dyspnoea and depression are major symptomatic determinants of HRQoL in IPF. FVC decline is associated with worsening HRQoL.

Accuracy of individual variables in the monitoring of long-term change in pulmonary sarcoidosis as judged by serial high-resolution CT scan data.

BACKGROUND: In pulmonary sarcoidosis, the optimal means of quantifying change is uncertain. The comparative usefulness of simple lung function trends and chest radiography remains unclear. We aimed to explore and contrast the disease-monitoring strategies of serial pulmonary function tests (PFTs) and chest radiography compared against morphologic change on high-resolution CT (HRCT) scan. METHODS: Seventy-three patients with sarcoidosis were identified who had two HRCT scans with concurrent chest radiography and PFTs. Chest radiography and HRCT scans were assessed by two radiologists for change in disease extent. Concordance between the scoring systems, as well as agreement between PFT trends (% change from baseline in FEV, FVC, and diffusing capacity of the lung for carbon monoxide [Dlco]), chest radiography, and chest HRCT scan change, were examined using the weighted κ coefficient of variation (Kw). RESULTS: There was fair agreement between change in extent of disease on chest radiograph and significant PFT trends (Kw = 0.35, P < .001) and moderate agreement between change in extent of disease on serial HRCT scan and significant PFT trends (Kw = 0.64, P < .0001). The integration of Dlco trends did not improve concordance between change on HRCT scan and PFT change. Change in gas transfer coefficient (ie, Dlco/alveolar volume) displayed no overall linkage with change in disease extent on chest radiograph (Kw = 0.07, P = .27) and only poor agreement with change in disease extent on HRCT scan (Kw = 0.17, P = .07). CONCLUSIONS: Significant PFT trends correlate better with morphologic change as defined by serial HRCT scan than extent of disease on radiograph. Isolated change in gas transfer coefficient is more frequently discordant with change in disease extent on chest radiograph and HRCT scan and may suggest a pulmonary vascular component.

Serum interleukin 6 is predictive of early functional decline and mortality in interstitial lung disease associated with systemic sclerosis.

OBJECTIVE: Biomarkers of progression of interstitial lung disease (ILD) are needed to allow early therapeutic intervention in patients with scleroderma-associated disease (SSc-ILD). METHODS: A panel of 8 serum cytokines [interleukin 6 (IL-6), IL-8, IL-10, CCL2, CXCL10, vascular endothelial growth factor, fibroblast growth factor 2, and CX3CL1] was assessed by Luminex bead technology in exploratory cohorts of 74 patients with SSc and 58 patients with idiopathic pulmonary fibrosis (IPF). Mortality and significant lung function decline [forced vital capacity (FVC) ≥ 10%; DLCO ≥ 15%] from date of serum collection were evaluated by proportional hazards analysis. Based on these findings, the prognostic value of serum IL-6, evaluated by ELISA, was assessed in a larger test cohort of 212 patients with SSc-ILD. RESULTS: In the exploratory cohort, only serum IL-6 was an independent predictor of DLCO decline in both IPF and SSc-ILD. The IL-6 threshold level most predictive of DLCO decline within a year was 7.67 pg/ml. In the larger test cohort, serum IL-6 > 7.67 pg/ml was predictive of decline in FVC (HR 2.58 ± 0.98, p = 0.01) and in DLCO (HR 3.2 ± 1.7, p = 0.02) within the first year, and predictive of death within the first 30 months (HR 2.69 ± 0.96, p = 0.005). When stratified according to severity (FVC < 70%), serum IL-6 > 7.67 pg/ml was predictive of functional decline or death within the first year in patients with milder disease (OR 3.1, 95% CI 1.4-7.2, p = 0.007), but not in those with severe ILD. CONCLUSION: In SSc-ILD, serum IL-6 levels appear to be predictive of early disease progression in patients with mild ILD, and could be used to target treatment in this group, if confirmed by prospective studies.