Annual Change in Pulmonary Function and Clinical Characteristics of Combined Pulmonary Fibrosis and Emphysema and Idiopathic Pulmonary Fibrosis: Over a 3-Year Follow-up

Combined Pulmonary Fibrosis and Emphysema: When Scylla and Charybdis Ally

Combined pulmonary fibrosis and emphysema (CPFE) is a recently recognized syndrome that, as its name indicates, involves the existence of both interstitial lung fibrosis and emphysema in one individual, and is often accompanied by pulmonary hypertension. This debilitating, progressive condition is most often encountered in males with an extensive smoking history, and is presented by dyspnea, preserved lung volumes, and contrastingly impaired gas exchange capacity. The diagnosis of the disease is based on computed tomography imaging, demonstrating the coexistence of emphysema and interstitial fibrosis in the lungs, which might be of various types and extents, in different areas of the lung and several relative positions to each other. CPFE bears high mortality and to date, specific and efficient treatment options do not exist. In this review, we will summarize current knowledge about the clinical attributes and manifestations of CPFE. Moreover, we will focus on pathophysiological and pathohistological lung phenomena and suspected etiological factors of this disease. Finally, since there is a paucity of preclinical research performed for this particular lung pathology, we will review existing animal studies and provide suggestions for the development of additional in vivo models of CPFE syndrome.

Syndrome of Combined Pulmonary Fibrosis and Emphysema: An Official ATS/ERS/JRS/ALAT Research Statement

Background: The presence of emphysema is relatively common in patients with fibrotic interstitial lung disease. This has been designated combined pulmonary fibrosis and emphysema (CPFE). The lack of consensus over definitions and diagnostic criteria has limited CPFE research. Goals: The objectives of this task force were to review the terminology, definition, characteristics, pathophysiology, and research priorities of CPFE and to explore whether CPFE is a syndrome. Methods: This research statement was developed by a committee including 19 pulmonologists, 5 radiologists, 3 pathologists, 2 methodologists, and 2 patient representatives. The final document was supported by a focused systematic review that identified and summarized all recent publications related to CPFE. Results: This task force identified that patients with CPFE are predominantly male, with a history of smoking, severe dyspnea, relatively preserved airflow rates and lung volumes on spirometry, severely impaired DlCO, exertional hypoxemia, frequent pulmonary hypertension, and a dismal prognosis. The committee proposes to identify CPFE as a syndrome, given the clustering of pulmonary fibrosis and emphysema, shared pathogenetic pathways, unique considerations related to disease progression, increased risk of complications (pulmonary hypertension, lung cancer, and/or mortality), and implications for clinical trial design. There are varying features of interstitial lung disease and emphysema in CPFE. The committee offers a research definition and classification criteria and proposes that studies on CPFE include a comprehensive description of radiologic and, when available, pathological patterns, including some recently described patterns such as smoking-related interstitial fibrosis. Conclusions: This statement delineates the syndrome of CPFE and highlights research priorities.

Prognosis of combined pulmonary fibrosis and emphysema: comparison with idiopathic pulmonary fibrosis alone

BACKGROUND

Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. However, whether CPFE has a higher or lower mortality than idiopathic pulmonary fibrosis (IPF) alone is still not clear. In this study we conducted a meta-analysis to assess the survival rate (SR) of CPFE versus IPF alone in clinical trials.

METHODS

We performed a systematic search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials for trials published prior to 31 March 2018. Extracts from the literature were analyzed with Review Manager version 5.3.

RESULTS

Thirteen eligible trials were included in this analysis (involving 1710 participants). Overall, the pooled results revealed that no statistically significant difference was detected in the 1-year [relative risk (RR) = 0.98, 95% confidence interval (CI): 0.94-1.03, p = 0.47], 3-year (RR = 0.83, 95% CI: 0.68-1.01, p = 0.06), and 5-year (RR = 0.80, 95% CI: 0.59-1.07, p = 0.14) SRs of CPFE versus IPF alone.

CONCLUSIONS

CPFE exhibits a very poor prognosis, similar to IPF alone. Additional studies are needed to provide more convincing data to investigate the natural history and outcome of patients with CPFE in comparison to IPF. The reviews of this paper are available via the supplemental material section.

Combined pulmonary fibrosis and emphysema as a clinicoradiologic entity: Characterization of presenting lung fibrosis and implications for survival

BACKGROUND

The prevalence of classifiable and unclassifiable causes of lung fibrosis and its implications for survival are mostly unknown in combined pulmonary fibrosis and emphysema (CPFE).

MATERIALS AND METHODS

Patients with >10% involvement of both emphysema and lung fibrosis seen over 11 years at our institution were reviewed independently by expert radiologists for fibrotic and emphysematous findings and overall fibrotic CT pattern. Underlying interstitial lung disease (ILD) diagnoses and baseline demographic and clinical characteristics were collated and assessed for predictors of comparative survival.

RESULTS

In this retrospective cohort, 179 CPFE patients were identified and categorized as 58 usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) (32%), 42 secondary ILD (23%), and 79 unclassifiable ILD (44%). The most prevalent (47%) radiologic pattern was 'unclassifiable', followed by 'consistent' and 'possible' UIP pattern in 38%. Adjusted predictors of mortality for the cohort as a whole included age (HR 1.03[1.01-1.06], P = 0.002), percent predicted diffusing capacity for carbon monoxide (unit HR 0.97 [0.96-0.99], P = 0.001), honeycombing (HR 1.58 [1.02-2.43], P = 0.04), and right ventricular dysfunction (HR 2.28 [1.39-3.97], P = 0.002). Survival was similar between CPFE with secondary ILD and CPFE with UIP/IPF, while CPFE with unclassifiable ILD had better comparative survival (Log rank = 0.026).

CONCLUSIONS

Our findings suggest only about a third of CPFE patients represent suspected UIP/IPF; the majority were clinically and radiologically unclassifiable ILD whose survival was comparatively better. Identifiable or secondary causes of lung fibrosis in CPFE occurred in about a fifth of presenting patients.

Heme scavenging reduces pulmonary endoplasmic reticulum stress, fibrosis, and emphysema

Pulmonary fibrosis and emphysema are irreversible chronic events after inhalation injury. However, the mechanism(s) involved in their development remain poorly understood. Higher levels of plasma and lung heme have been recorded in acute lung injury associated with several insults. Here, we provide the molecular basis for heme-induced chronic lung injury. We found elevated plasma heme in chronic obstructive pulmonary disease (COPD) (GOLD stage 4) patients and also in a ferret model of COPD secondary to chronic cigarette smoke inhalation. Next, we developed a rodent model of chronic lung injury, where we exposed C57BL/6 mice to the halogen gas, bromine (Br2) (400 ppm, 30 minutes), and returned them to room air resulting in combined airway fibrosis and emphysematous phenotype, as indicated by high collagen deposition in the peribronchial spaces, increased lung hydroxyproline concentrations, and alveolar septal damage. These mice also had elevated pulmonary endoplasmic reticulum (ER) stress as seen in COPD patients; the pharmacological or genetic diminution of ER stress in mice attenuated Br2-induced lung changes. Finally, treating mice with the heme-scavenging protein, hemopexin, reduced plasma heme, ER stress, airway fibrosis, and emphysema. This is the first study to our knowledge to report elevated heme in COPD patients and establishes heme scavenging as a potential therapy after inhalation injury.

Effect of Emphysema Extent on Serial Lung Function in Patients with Idiopathic Pulmonary Fibrosis

RATIONALE

Patients with idiopathic pulmonary fibrosis and emphysema may have artificially preserved lung volumes.

OBJECTIVES

In this post hoc analysis, we investigated the relationship between baseline emphysema and fibrosis extents, as well as pulmonary function changes, over 48 weeks.

METHODS

Data were pooled from two phase III, randomized, double-blind, placebo-controlled trials of IFN-γ-1b in idiopathic pulmonary fibrosis (GIPF-001 [NCT00047645] and GIPF-007 [NCT00075998]). Patients with Week 48 data, baseline high-resolution computed tomographic images, and FEV₁/FVC ratios less than 0.8 or greater than 0.9 (<0.7 or >0.9 in GIPF-007), as well as randomly selected patients with ratios of 0.8-0.9 and 0.7-0.8, were included. Changes from baseline in pulmonary function at Week 48 were analyzed by emphysema extent. The relationship between emphysema and fibrosis extents and change in pulmonary function was assessed using multivariate linear regression.

MEASUREMENTS AND MAIN RESULTS

Emphysema was identified in 38% of patients. A negative correlation was observed between fibrosis and emphysema extents (r = -0.232; P < 0.001). In quartile analysis, patients with the greatest emphysema extent (28 to 65%) showed the smallest FVC decline, with a difference of 3.32% at Week 48 versus patients with no emphysema (P = 0.047). In multivariate analyses, emphysema extent greater than or equal to 15% was associated with significantly reduced FVC decline over 48 weeks versus no emphysema or emphysema less than 15%. No such association was observed for diffusing capacity of the lung for carbon monoxide or composite physiologic index.

CONCLUSIONS

FVC measurements may not be appropriate for monitoring disease progression in patients with idiopathic pulmonary fibrosis and emphysema extent greater than or equal to 15%.

Severe pulmonary hypertension due to combined pulmonary fibrosis and emphysema: another cause of death among smokers

In 2005, the combined pulmonary fibrosis and emphysema (CPFE) was first defined as a distinct entity, which comprised centrilobular or paraseptal emphysema in the upper pulmonary lobes, and fibrosis in the lower lobes accompanied by reduced diffused capacity of the lungs for carbon monoxide (DLCO). Recently, the fibrosis associated with the connective tissue disease was also included in the diagnosis of CPFE, although the exposure to tobacco, coal, welding, agrochemical compounds, and tire manufacturing are the most frequent causative agents. This entity characteristically presents reduced DLCO with preserved lung volumes and severe pulmonary hypertension, which is not observed in emphysema and fibrosis alone. We present the case of a 63-year-old woman with a history of heavy tobacco smoking abuse, who developed progressive dyspnea, severe pulmonary hypertension, and cor pulmonale over a 2-year period. She attended the emergency facility several times complaining of worsening dyspnea that was treated as decompensate chronic obstructive pulmonary disease (COPD). The imaging examination showed paraseptal emphysema in the upper pulmonary lobes and fibrosis in the middle and lower lobes. The echo Doppler cardiogram revealed the dilation of the right cardiac chambers and pulmonary hypertension, which was confirmed by pulmonary trunk artery pressure measurement by catheterization. During this period, she was progressively restricted to the minimal activities of daily life and dependent on caregivers. She was brought to the hospital neurologically obtunded, presenting anasarca, and respiratory failure, which led her to death. The autopsy showed signs of pulmonary hypertension and findings of fibrosis and emphysema in the histological examination of the lungs. The authors highlight the importance of the recognition of this entity in case of COPD associated with severe pulmonary hypertension of unknown cause.

Body Mass Index and arterial blood oxygenation as prognostic factors in patients with idiopathic pleuroparenchymal fibroelastosis

Background: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) was recently proposed as an entity to be included among rare idiopathic interstitial pneumonias (IIPs). However, the cause, clinical features and prognosis of this rare entity have not been elucidated. Objectives: We aimed to examine the clinical features, outcomes and prognostic factors for IPPFE in comparison to those of idiopathic pulmonary fibrosis (IPF). Methods: We retrospectively analyzed 20 patients with IPPFE and 71 with IPF. We compared clinical features, blood examination data, and respiratory functions at the time of diagnosis. Results: The IPPFE group had a significantly lower body mass index (BMI), percent forced vital capacity (%FVC), total lung capacity (%TLC) and expiratory reserve volume (%ERV), as well as a higher residual volume to TLC (RV/TLC) ratio than the IPF group. The annual FVC changes in the IPPFE group (-326ml/year) were significantly larger than those in the IPF group (-142ml/year). Survival was significantly poorer in the IPPFE than in the IPF group (P = 0.021). BMI and the partial pressure of oxygen in arterial blood (PaO₂) were significantly related to the outcome of IPPFE. Conclusions: Our present results indicate the prognosis of IPPFE patients to be poorer than that of IPF patients. We advocate that BMI and arterial blood PaO₂ be determined at the first visit as these parameters are closely related to patients' outcomes. Prospective evaluation of IPPFE starting in the subclinical phase is necessary to assure that appropriate measures are taken before progression. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 35-40).

Understanding COPD-overlap syndromes

INTRODUCTION

Chronic obstructive pulmonary disease accounts for a large burden of lung disease. It can 'overlap' with other respiratory diseases including bronchiectasis, fibrosis and obstructive sleep apnea (OSA). While COPD alone confers morbidity and mortality, common features with contrasting clinical outcomes can occur in COPD 'overlap syndromes'. Areas covered: Given the large degree of heterogeneity in COPD, individual variation to treatment is adopted based on its observed phenotype, which in turn overlaps with features of other respiratory disease states such as asthma. This is coined asthma-COPD overlap syndrome ('ACOS'). Other examples of such overlapping clinical states include bronchiectasis-COPD ('BCOS'), fibrosis-COPD ('FCOS') and OSA-COPD ('OCOS'). The objective of this review is to highlight similarities and differences between the COPD-overlap syndromes in terms of risk factors, pathophysiology, diagnosis and potential treatment differences. Expert commentary: As a consequence of COPD overlap syndromes, a transition from the traditional 'one size fits all' treatment approach is necessary. Greater treatment stratification according to clinical phenotype using a precision medicine approach is now required. In this light, it is important to recognize and differentiate COPD overlap syndromes as distinct disease states compared to individual diseases such as asthma, COPD, fibrosis or bronchiectasis.

Combined pulmonary fibrosis and emphysema: The many aspects of a cohabitation contract

Combined pulmonary fibrosis and emphysema (CPFE) is a clinical entity characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. Patients with this condition experience severe dyspnea and impaired gas exchange with preserved lung volumes. The diagnosis of the CPFE syndrome is based on HRCT imaging, showing the coexistence of emphysema and pulmonary fibrosis both in varying extent and locations within the lung parenchyma. Individual genetic background seem to predispose to the development of the disease. The risk of the development of pulmonary hypertension in patients with CPFE is high and related to poor prognosis. CPFE patients also present a high risk of lung cancer. Mortality is significant in patients with CPFE and median survival is reported between 2.1 and 8.5 years. Currently, no specific recommendations are available regarding the management of patients with CPFE. In this review we provide information on the existing knowledge on CPFE regarding the pathophysiology, clinical manifestations, imaging, complications, possible therapeutic interventions and prognosis of the disease.

Development of novel agents for idiopathic pulmonary fibrosis: progress in target selection and clinical trial design

Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disease. Until recently, the standard therapy for this disease has been essentially supportive, with the exception of a minority of patients who were eligible for lung transplantation. The development pathway for novel medications for IPF has been complicated. There have been several challenges, including an incomplete understanding of the pathogenesis, unpredictable clinical course, lack of validated biomarkers, the low clinical predictive value of animal models of lung injury, and the need to commit to large clinical trials of long duration to obtain initial evidence of clinical efficacy. Despite these challenges, the combination of recent advances in translational medicine and the unprecedented increase in clinical data accumulated from recent large clinical trials has stimulated an increase in the number of clinical development programs for IPF. Clinical programs are increasingly characterized by rational target selection, preclinical optimization of therapeutic molecules, and an emphasis on efficient clinical trial design. A lower rate of functional decline in patients treated with pirfenidone and nintedanib was demonstrated in large clinical trials. In October 2014, these two drugs became the first agents to be approved by the US Food and Drug Administration for the treatment of IPF. (Pirfenidone had already been approved in several countries outside the United States.) In November 2014, the European Medicines Agency approved the use of nintedanib for IPF. The landscape for management of IPF has markedly changed with the advent of approved therapeutic options for IPF. In this article, we review the strategies that are being used to increase the likelihood of success in clinical development programs of novel disease-modifying agents in IPF.

Combined pulmonary fibrosis and emphysema (CPFE): an entity different from emphysema or pulmonary fibrosis alone

Chronic obstructive pulmonary disease (COPD) and idiopathic interstitial pneumonias (IIP), with different radiological, pathological, functional and prognostic characteristics, have been regarded as separate entities for a long time. However, there is an increasing recognition of the coexistence of emphysema and pulmonary fibrosis in individuals. The association was first described as a syndrome by Cottin in 2005, named "combined pulmonary fibrosis and emphysema (CPFE)", which is characterized by exertional dyspnea, upper-lobe emphysema and lower-lobe fibrosis, preserved lung volume and severely diminished capacity of gas exchange. CPFE is frequently complicated by pulmonary hypertension, acute lung injury and lung cancer and prognosis of it is poor. Treatments for CPFE patients with severe pulmonary hypertension are less effective other than lung transplantation. However, CPFE has not yet attracted wide attention of clinicians and there is no research systematically contrasting the differences among CPFE, emphysema/COPD and IIP at the same time. The authors will review the existing knowledge of CPFE and compare them to either entity alone for the first time, with the purpose of improving the awareness of this syndrome and exploring novel effective therapeutic strategies in clinical practice.