Outcomes of patients with progressive fibrosing interstitial lung disease (PF-ILD) - data from a prospective ILD registry

Background: Real life data on outcome of patients with PF-ILD are scant. Method: The prospective German EXCITING registry was evaluated for patients with PF-ILD, defined as either decline in vital capacity (VC) ≥ 10 % or respiratory hospitalisation within 24 months. Only patients with ≥2 VC measures in 24 months were analysed. Results: Out of 601 patients, 128 patients with PF-ILD were identified. Baseline characteristics were 47% male, age 69 years, 47% ex-/smokers, mean VC 75%, DLCO 40%, 6MWD 371 m, GAP index I 45%, II 31%, III 20%. Patients had non-specific interstitial pneumonia (16%), unclassifiable ILD (15%), hypersensitivity pneumonitis (31%), ILD in connective tissue diseases (21%), asbestos (5%), other ILDs (12%). 5-year survival rates for PF-ILD were 78%, compared to 65% for IPF (n=152, 76% male, 74 years, VC 72%, DLCO 46%) and 85% for non-PF ILD (n=45; 58% male, 67 years, VC 68%, DLCO 49%) (fig.). In a cox regression model (comparator IPF), hazard ratios for death were 0.62 (0.42-0.9) for PF-ILD (p=0.013) and 0.29 (0.13-0.64) for non-PF-ILD (p=0.002). In a supervised learning approach age ≥55 years and BMI < 34 were predictors of PF. An alternative PF definition (VC decline ≥ 5 % in 24 months) was discrepant in patient assignment in 17%. Conclusions: PF-ILD is associated with a significantly impaired survival compared to non-PF ILD patients, but better than IPF.