Figures
- FIGURE 1
The Kaplan–Meier survival curve in patients with typical idiopathic pulmonary fibrosis (IPF) (solid line) (n=195) and idiopathic pleuroparenchymal fibroelastosis (IPPFE) with usual interstitial pneumonia (UIP) (dashed line) (n=64) (median survival time 62.3 months versus 34.0 months, p<0.0001).
- FIGURE 2
Change in forced vital capacity (FVC) before and after treatments with antifibrotic agents (idiopathic pleuroparenchymal fibroelastosis (IPPFE) with usual interstitial pneumonia (UIP)/typical idiopathic pulmonary fibrosis (IPF)in 32 out of 58 cases). There were no differences between the groups in FVC value 6 months before treatment with antifibrotic agents (IPPFE with UIP versus typical IPF = −0.21±0.16 L versus −0.20±0.19 L; p=0.95). However, more significantly reduced FVC values 6 months after treatment with antifibrotic agents were found in patients with IPPFE with UIP than in those with typical IPF (IPPFE with UIP versus typical IPF = −0.15±0.17 L versus −0.004±0.18 L; p=0.0002; IPPFE with UIP: before 6 months versus at the onset of treatments versus after 6 months = 1.96±0.66 L versus 1.75±0.64 L versus 1.61±0.61 L; p<0.0001, p<0.0001; typical IPF: before 6 months versus at the onset of treatments versus after 6 months = 2.25±0.61 L versus 2.05±0.62 L versus 2.05±0.64 L, p<0.0001, p=1.00). Two-way repeated measure ANOVA with Bonferroni's multiple comparison.
- FIGURE 3
Change in % predicted forced vital capacity (FVC) during follow-up. a) Linear mixed model (LMM) analysis showed that the decline in the slope of FVC during follow-up was significantly different between the two groups (p=0.0003). Patients with typical idiopathic pulmonary fibrosis (IPF) had a significantly higher baseline FVC than those with idiopathic pleuroparenchymal fibroelastosis (IPPFE) with usual interstitial pneumonia (UIP) (77.4±18.7% versus 63.9±15.7%, p<0.0001). b) Patients with IPPFE with UIP during follow-up who were treated with antifibrotic agents had a significantly lower baseline FVC and a more rapid decline in FVC compared with that in those with typical IPF treated with antifibrotic agents (p=0.0002). Patients with typical IPF had a significantly higher baseline FVC than those with IPPFE with UIP (73.8±17.8% versus 64.6±14.9%, p=0.003).
Tables
- TABLE 1
Demographic and baseline patient characteristics
Variable IPPFE with UIP Typical IPF p-value Subjects 64 195 Males/females 43/21 162/33 0.012 Age years 72.7±7.1 72.7±7.1 0.972 BMI kg·m−2 17.6±2.9 22.7±3.5 <0.0001 Current/former/never smokers 6/34/24 26/136/33 0.003 mMRC score 0/I/II/III/IV 5/25/23/6/5 22/61/60/40/12 0.248 Severity of IPF GAP stage I/II/III 28/24/12 99/68/28 0.555 Primary lung cancer 0 (0%) 12 (6.2%) 0.042 Pneumothorax 20 (31.3%) 3 (1.5%) <0.0001 Acute exacerbation 19 (29.7%) 64 (32.8%) 0.757 Nintedanib 8 (12.5%) 38 (19.4%) 0.06 Pirfenidone 26 (40.6%) 53 (27.1%) 0.06 Histological UIP diagnosis 10 (15.6%) 42 (21.5%) 0.370 Histological PPFE diagnosis 10 (15.6%) 0 (0%) <0.0001 Observation period months 30.7±19.7 38.9±34.2 0.07 Data are presented as n, mean±sd or n (%), unless otherwise stated. IPPFE: idiopathic pleuroparenchymal fibroelastosis; UIP: usual interstitial pneumonia; IPF: idiopathic pulmonary fibrosis; BMI: body mass index; mMRC: modified Medical Research Council; GAP: gender, age and lung physiology; PPFE: pleuroparenchymal fibroelastosis.
- TABLE 2
Comparison of pulmonary function tests, serum markers and chest computed tomography (CT) findings between patients with idiopathic pleuroparenchymal fibroelastosis (IPPFE) with usual interstitial pneumonia (UIP) and typical idiopathic pulmonary fibrosis (IPF)
Variable IPPFE with UIP Typical IPF p-value Subjects n 64 195 FVC % predicted 66.7±16.9 78.5±18.8 0.0001 FEV1 % predicted 86.1±24.9 97.2±47.3 0.073 TLC % predicted 74.4±15.7 77.9±16.6 0.153 RV % predicted 90.6±27.3 82.9±21.9 0.026 DLCO % predicted 66.2±25.2 60.3±20.4 0.072 CPI 41.5±18.2 43.0±21.7 0.621 KL-6 U·mL−1 823±485 1123±743 0.003 SP-D ng·mL−1 283±162 293±234 0.742 PaO2 mmHg 84.1±13.4 80.8±13.1 0.087 PaCO2 mmHg 43.6±5.8 39.4±3.9 <0.0001 Fibrosis score 1.7±0.7 1.6±0.6 0.953 Extent of bronchiectasis 1.8±0.8 1.6±0.7 0.106 CT pattern: UIP/possible UIP/inconsistent with UIP 169/22/4 Data are presented as mean±sd unless otherwise stated. FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; TLC: total lung capacity; RV: residual volume; DLCO: diffusing capacity of the lung for carbon monoxide; CPI: composite physiological index; KL-6: Krebs von den Lungen-6; SP-D: surfactant protein D; PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension.
- TABLE 3
Fine–Gray univariable and multivariable competing risks models demonstrating prognostic factors for survival in patients with idiopathic pleuroparenchymal fibroelastosis (IPPFE) with usual interstitial pneumonia (UIP) (n=64)
Variable Univariate Multivariate SHR (95% CI) p-value SHR (95% CI) p-value Age 1.000 (0.945–1.058) 0.991 Female sex 1.659 (0.753–3.651) 0.209 BMI 0.757 (0.632–0.907) 0.003 0.806 (0.659–0.987) 0.037 Ever-smokers 0.754 (0.350–1.625) 0.472 mMRC score 0.996 (0.687–1.445) 0.985 SpO2 <90% 1.284 (0.601–2.742) 0.518 FVC % predicted 0.955 (0.929–0.982) 0.001 0.971 (0.946–0.995) 0.019 Prednisolone use 0.502 (0.223–1.132) 0.097 0.228 (0.072–0.727) 0.012 Pneumothorax 3.029 (1.366–6.714) 0.006 SHR: subdistribution hazard ratio; BMI: body mass index; mMRC: modified Medical Research Council; SpO2: peripheral oxygen saturation; FVC: forced vital capacity.
- TABLE 4
Comparison of causes of death between idiopathic pleuroparenchymal fibroelastosis (IPPFE) with usual interstitial pneumonia (UIP) and typical idiopathic pulmonary fibrosis (IPF)
Variable IPPFE with UIP Typical IPF p-value Subjects n 64 195 Lung cancer 0 (0%) 6 (3.0%) 0.341 Pneumonia 12 (18.7%) 16 (8.2%) 0.034 Acute exacerbation 9 (14.0%) 32 (16.4%) 0.843 Chronic deterioration 20 (31.2%) 15 (7.6%) <0.0001 Others 3 (4.6%) 11 (5.6%) 1.000 Unknown 4 (6.2%) 2 (1.0%) 0.034 Data are presented as n (%) unless otherwise stated.
- TABLE 5
Multivariate logistic regression analysis of predictive factors for efficacy of antifibrotic agents (n=125)
Variable OR (95% CI) p-value Age 1.013 (0.948–1.086) 0.699 Male sex 0.799 (0.268–2.587) 0.697 BMI 1.079 (0.918–1.277) 0.354 GAP stage 1.644 (0.845–3.218) 0.142 IPPFE with UIP 7.096 (2.018–28.270) 0.002 BMI: body mass index; GAP: gender, age and lung physiology; IPPFE: idiopathic pleuroparenchymal fibroelastosis; UIP: usual interstitial pneumonia.
