Chronic Fibrotic Lung Disease Research Articles

Comprehensive and Individualized Patient Care in Idiopathic Pulmonary Fibrosis: Refining Approaches to Diagnosis, Prognosis, and Treatment

As seen in this CME online activity (available at http://courses.elseviercme.com/chest16/647e), idiopathic pulmonary fibrosis (IPF) is a specific form of chronic progressive fibrotic lung disease of unknown cause. It is the most common form of idiopathic interstitial pneumonia in adults. Its prevalence among US Medicare beneficiaries has more than doubled in the past 14 years. With the approval of two agents that reduce functional decline and disease progression, and the 2015 update of the American Thoracic Society guidelines on the treatment of IPF, the options for appropriate clinical management of the disease have become well defined. Early diagnosis and early initiation of treatment are of critical importance for long-term clinical outcomes. The diagnostic process, which may require a multidisciplinary team of experts, is centered on excluding systemic diseases and exposures and identifying a pattern of usual interstitial pneumonia on high-resolution CT or surgical lung biopsy results. Familiarity with the 2015 American Thoracic Society guidelines is critical with respect to both the treatments that the guidelines recommend and those that they advise against. Standard immunosuppressive therapy is no longer indicated, whereas pirfenidone, nintedanib, and antacid therapy are all conditionally recommended for use. Individualizing treatment is important in light of potential improved adherence to both drug therapy and health behaviors. An early referral to an interstitial lung disease center offers the advantages of comprehensive diagnostic and disease-management expertise, potential enrollment in a clinical trial, and evaluation for transplantation.

Interstitial Lung Disease in India. Results of a Prospective Registry

Interstitial lung disease (ILD) is a heterogeneous group of acute and chronic inflammatory and fibrotic lung diseases. Existing ILD registries have had variable findings. Little is known about the clinical profile of ILDs in India. To characterize new-onset ILDs in India by creating a prospective ILD using multidisciplinary discussion (MDD) to validate diagnoses. Adult patients of Indian origin living in India with new-onset ILD (27 centers, 19 Indian cities, March 2012-June 2015) without malignancy or infection were included. All had connective tissue disease (CTD) serologies, spirometry, and high-resolution computed tomography chest. ILD pattern was defined by high-resolution computed tomography images. Three groups independently made diagnoses after review of clinical data including that from prompted case report forms: local site investigators, ILD experts at the National Data Coordinating Center (NDCC; Jaipur, India) with MDD, and experienced ILD experts at the Center for ILD (CILD; Seattle, WA) with MDD. Cohen's κ was used to assess reliability of interobserver agreement. A total of 1,084 patients were recruited. Final diagnosis: hypersensitivity pneumonitis in 47.3% (n = 513; exposure, 48.1% air coolers), CTD-ILD in 13.9%, and idiopathic pulmonary fibrosis in 13.7%. Cohen's κ: 0.351 site investigator/CILD, 0.519 site investigator/NDCC, and 0.618 NDCC/CILD. Hypersensitivity pneumonitis was the most common new-onset ILD in India, followed by CTD-ILD and idiopathic pulmonary fibrosis; diagnoses varied between site investigators and CILD experts, emphasizing the value of MDD in ILD diagnosis. Prompted case report forms including environmental exposures in prospective registries will likely provide further insight into the etiology and management of ILD worldwide.

The role of miR-497-5p in myofibroblast differentiation of LR-MSCs and pulmonary fibrogenesis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and fatal fibrotic lung disease characterized by profound changes in stem cell differentiation, epithelial cell phenotypes and fibroblast proliferation. In our study, we found that miR-497-5p was significantly upregulated both during myofibroblast differentiation of lung resident mesenchymal stem cells (LR-MSCs) and in the lung tissues of a pulmonary fibrosis model. In addition, as determined by luciferase assays and Western blot analysis, reversion-inducing cysteine-rich protein with kazal motifs (Reck) was identified to be one of the target genes of miR-497-5p, and Reck could suppress the expression of matrix metalloproteinase-2 (Mmp2) and Mmp9, which could activate latent transforming growth factor-β1 (TGF-β1). To test the potential therapeutic significance of this miRNA, we modulated the expression of miR-497-5p in LR-MSCs and relevant animal models. The results demonstrated that upregulation of miR-497-5p could induce LR-MSCs to differentiate into myofibroblasts and promote pulmonary fibrogenesis, while inhibition of its expression could effectively retard these processes. In conclusion, our work supports that controlling pulmonary fibrogenesis via inhibition of miR-497-5p expression may provide a potential therapeutic strategy for IPF.

Reply: Promise and Limitations of Relaxin-based Therapies in Chronic Fibrotic Lung Diseases.

Reply: Promise and Limitations of Relaxin-based Therapies in Chronic Fibrotic Lung Diseases.

Promise and Limitations of Relaxin-based Therapies in Chronic Fibrotic Lung Diseases.

Promise and Limitations of Relaxin-based Therapies in Chronic Fibrotic Lung Diseases.

Recent Advances and Future Needs in Interstitial Lung Diseases.

Interstitial lung diseases (ILDs) are a diverse range of conditions affecting the lung interstitium. The prototypic ILD, idiopathic pulmonary fibrosis (IPF), is a chronic progressive fibrotic lung disease with a median survival of only 3 years from the time of diagnosis. Recently significant progress has been made in both our understanding of the pathogenesis and of the therapeutic targeting of IPF. This culminated in the worldwide approval of the first antifibrotic therapies nintedanib and pirfenidone. While an important first step, patients continue to progress and better therapies are urgently required. The aim of this article is to highlight some of the recent advances that have been made in our understanding of genetics, disease classification, clinical trial design, and novel antifibrotic therapy in IPF. It discusses future priorities if we are to continue to increase the length and quality of life of patients with IPF, and considers possible approaches to translate the progress made in IPF to other progressive fibrotic lung diseases where our understanding remains limited.

Follistatin-like 1 Aggravates Silica-Induced Mouse Lung Injury and Is a Potential Biomarker of Chronic Fibrotic Lung Diseases

Follistatin-like 1 Aggravates Silica-Induced Mouse Lung Injury and Is a Potential Biomarker of Chronic Fibrotic Lung Diseases

All-case post-marketing surveillance of 1371 patients treated with pirfenidone for idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrotic lung disease with a median survival of 2-5 years and limited treatment options. In 2008, pirfenidone became the first drug to be approved for IPF treatment in Japan. The aim of this study was to assess the safety of pirfenidone for IPF treatment in a clinical setting. We conducted a safety-oriented post-marketing surveillance of all patients with IPF who were administered pirfenidone in the first year after its launch in Japan. This was a prospective, non-interventional, observational study. Case report forms were used to collect survey data, comprising adverse events, acute exacerbations, patient demographics, concomitant drug use, and concurrent treatment data. Of the 1371 patients available for safety evaluation, two-thirds had stage III-IV disease. The incidence of total adverse drug reactions (ADRs) was 64.6%. ADRs with an incidence of ≥3% were decreased appetite, photosensitivity reaction, nausea, abdominal discomfort, malaise, somnolence, and hepatic function abnormal. This safety profile was consistent with the findings in phase II and III trials in Japan. The discontinuation rates due to adverse events at 12 months for each disease stage were similar; however, discontinuation caused by disease progression increased with disease severity. Treatment with pirfenidone stabilized both vital capacity and subjective symptoms in most patients (70-80%) treated for at least 6 months. This post-marketing surveillance in Japan showed that pirfenidone was generally well tolerated in patients with IPF, including those with severe lung function impairment.

Developments in the management of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF), a chronic progressive fibrotic interstitial lung disease (ILD) of unknown origin,1 has seen significant change in its management over the last 15 years.2 In addition, two...

Molecular classification of idiopathic pulmonary fibrosis: personalized medicine, genetics and biomarkers.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic lung disease associated with high morbidity and poor survival. Characterized by substantial disease heterogeneity, the diagnostic considerations, clinical course and treatment response in individual patients can be variable. In the past decade, with the advent of high-throughput proteomic and genomic technologies, our understanding of the pathogenesis of IPF has greatly improved and has led to the recognition of novel treatment targets and numerous putative biomarkers. Molecular biomarkers with mechanistic plausibility are highly desired in IPF, where they have the potential to accelerate drug development, facilitate early detection in susceptible individuals, improve prognostic accuracy and inform treatment recommendations. Although the search for candidate biomarkers remains in its infancy, attractive targets such as MUC5B and MPP7 have already been validated in large cohorts and have demonstrated their potential to improve clinical predictors beyond that of routine clinical practices. The discovery and implementation of future biomarkers will face many challenges, but with strong collaborative efforts among scientists, clinicians and the industry the ultimate goal of personalized medicine may be realized.

Hyperoxia downregulates angiotensin-converting enzyme-2 in human fetal lung fibroblasts.

Background:Angiotensin (ANG) II is involved in experimental hyperoxia-induced lung fibrosis. Angiotensin-converting enzyme-2 (ACE-2) degrades ANG II and is thus protective, but is downregulated in adult human and experimental lung fibrosis. Hyperoxia is a known cause of chronic fibrotic lung disease in neonates, but the role of ACE-2 in neonatal lung fibrosis is unknown. We hypothesized that ACE-2 in human fetal lung cells might be downregulated by hyperoxic gas.Methods:Fetal human lung fibroblast IMR90 cells were exposed to hyperoxic (95% O2/5% CO2) or normoxic (21% O2/5% CO2) gas in vitro. Cells and culture media were recovered separately for assays of ACE-2 enzymatic activity, mRNA, and immunoreactive protein.Results:Hyperoxia decreased ACE-2 immunoreactive protein and enzyme activity in IMR90 cells (both P < 0.01), but did not change ACE-2 mRNA. ACE-2 protein was increased in the cell supernatant, suggesting protease-mediated ectodomain shedding. TAPI-2, an inhibitor of TNF-α−converting enzyme (TACE/ADAM17), prevented both the decrease in cellular ACE-2 and the increase in soluble ACE-2 (both P < 0.05).Conclusion:These data show that ACE-2 is expressed in fetal human lung fibroblasts but is significantly decreased by hyperoxic gas. They also suggest that hyperoxia decreases ACE-2 through a shedding mechanism mediated by ADAM17/TACE.Supplementary informationThe online version of this article (doi:10.1038/pr.2015.27) contains supplementary material, which is available to authorized users.

IPF Care: a support program for patients with idiopathic pulmonary fibrosis treated with pirfenidone in Europe.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible fibrotic lung disease that requires long-term treatment. Given the importance of adherence to treatment and management of adverse events (AEs), patients with IPF need long-term, high-quality support in living with their condition, and adhering to therapy so they can derive maximum benefit. The IPF Care Patient Support Program (IPF Care) provides support, education, and empowerment to patients receiving pirfenidone for the treatment of IPF in Europe, through the provision of frequent, patient-managed discussions with specialist IPF nurses. In this review, we describe the structure of IPF Care in the United Kingdom (UK) and Austria, two of the longest-running IPF Care programs to date, and describe the benefits that these programs provide to patients with IPF. Analysis of results demonstrates a low rate of discontinuation from the program, and provides insight into the questions and concerns that patients express, not only with respect to pirfenidone (the only approved treatment for IPF at the time of analysis), but also in relation to other aspects of living with IPF. Pirfenidone dose modifications are common in patients in IPF Care and AEs most commonly occur early in treatment, with the majority of affected patients continuing on a stable maintenance dose. This highlights the value of the advice and support that patients receive in IPF Care regarding management of AEs and staying on treatment. Patient satisfaction was high in a survey of the UK program, with patients reporting high scores regarding ‘feeling in control of their condition’, ‘knowing what to expect from treatment’, and ‘feeling confident about how their disease is managed’. IPF Care in Europe will continue to evolve over time, striving to provide individually tailored support and patient-friendly information to improve treatment outcomes and quality of life for patients living with IPF.Electronic supplementary materialThe online version of this article (doi:10.1007/s12325-015-0183-7) contains supplementary material, which is available to authorized users.

Characteristics of gastro-esophageal reflux in patients with idiopathic pulmonary fibrosis

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic fibrotic lung disease with a median survival rate ranging from 2 to 3years from diagnosis. Recent data have illustrated the role of gastro-esophageal reflux (GER) in the pathogenesis and potential management of IPF patients. Although it is recognized that GER is increased among IPF patients, its prevalence and characteristics had been poorly defined. Patients and methodsForty patients were recruited; 20 with a diagnosis of IPF and the other, 20 with interstitial lung disease other than IPF (non IPF patients). All patients underwent pulmonary high-resolution computed tomography (HRCT) scan and impedance-pH monitoring while off antisecretory therapy. The presence of pulmonary fibrosis was assessed using validated HRCT scores. Reflux features included distal esophageal acid exposure, number of acid/weakly acidic reflux episodes and their proximal migration. ResultsSeventeen (85%) patients out of 20 with IPF had an abnormal distal acid exposure, compared with 7 (35%) out of 20 non IPF patients (p=0.003). Percentage total acid exposure time (AET) with pH<4 was significantly higher in IPF compared with non IPF patients (median (range) 10.1 (5.1–16.3) versus 3 (1.2–8.3), respectively; p<0.0001). In IPF patients the total (both acid and weakly acidic) numbers of reflux episodes [80 (45–99)], acid reflux [46 (25–57)] and weakly acidic reflux [35 (20–45)] were significantly higher than those of non IPF patients (45 (29–70), 28 (18–40) and 19 (10–30), respectively; p<0.0001). Also, more reflux episodes reached the proximal esophagus [54 (28–69)] in IPF patients than non-IPF patients [18 (8–32); p<0.0001]. In IPF patients there was a significant positive correlation between degree of pulmonary fibrosis (HRCT score) and total number of reflux episodes in both the distal (r2=0.57, p=0.008) and proximal (r2=0.61, p=0.004) esophagus. In contrast, in non IPF patients a non significant correlation was found between degree of pulmonary fibrosis and total number of reflux episodes in both the distal (r2=0.17, p=0.48) and proximal (r2=0.23, p=0.34) esophagus. ConclusionIPF patients have greater GER rate compared to non IPF ones. Not only acid reflux, but also weakly acidic reflux is significantly increased among IPF patients.

The Antifibrotic Effects and Mechanisms of MicroRNA-26a Action in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and high-lethality fibrotic lung disease characterized by excessive fibroblast proliferation, extracellular matrix accumulation, and, ultimately, loss of lung function. Although dysregulation of some microRNAs (miRs) has been shown to play important roles in the pathophysiological processes of IPF, the role of miRs in fibrotic lung diseases is not well understood. In this study, we found downregulation of miR-26a in the lungs of mice with experimental pulmonary fibrosis and in IPF, which resulted in posttranscriptional derepression of connective tissue growth factor (CTGF), and induced collagen production. More importantly, inhibition of miR-26a in the lungs caused pulmonary fibrosis in vivo, whereas overexpression of miR-26a repressed transforming growth factor (TGF)-β1-induced fibrogenesis in MRC-5 cells and attenuated experimental pulmonary fibrosis in mice. Our study showed that miR-26a was downregulated by TGF-β1-mediated phosphorylation of Smad3. Moreover, miR-26a inhibited the nuclear translocation of p-Smad3 through directly targeting Smad4, which determines the nuclear translocation of p-Smad2/Smad3. Taken together, our experiments demonstrated the antifibrotic effects of miR-26a in fibrotic lung diseases and suggested a new strategy for the prevention and treatment of IPF using miR-26a. The current study also uncovered a novel positive feedback loop between miR-26a and p-Smad3, which is involved in pulmonary fibrosis.

Danger-associated molecular patterns and danger signals in idiopathic pulmonary fibrosis.

The chronic debilitating lung disease, idiopathic pulmonary fibrosis (IPF), is characterized by a progressive decline in lung function, with a median mortality rate of 2-3 years after diagnosis. IPF is a disease of unknown cause and progression, and multiple pathways have been demonstrated to be activated in the lungs of these patients. A recent genome-wide association study of more than 1,000 patients with IPF identified genes linked to host defense, cell-cell adhesion, and DNA repair being altered due to fibrosis (Fingerlin, et al. Nat Genet 2013;45:613-620). Further emerging data suggest that the respiratory system may not be a truly sterile environment, and it exhibits an altered microbiome during fibrotic disease (Molyneaux and Maher. Eur Respir Rev 2013;22:376-381). These altered host defense mechanisms might explain the increased susceptibility of patients with IPF to microbial- and viral-induced exacerbations. Moreover, chronic epithelial injury and apoptosis are key features in IPF, which might be mediated, in part, by both pathogen-associated (PA) and danger-associated molecular patterns (MPs). Emerging data indicate that both PAMPs and danger-associated MPs contribute to apoptosis, but not necessarily in a manner that allows for the removal of dying cells, without further exacerbating inflammation. In contrast, both types of MPs drive cellular necrosis, leading to an exacerbation of lung injury and/or infection as the debris promotes a proinflammatory response. Thus, this Review focuses on the impact of MPs resulting from infection-driven apoptosis and necrosis during chronic fibrotic lung disease.

Efficacy and safety of pirfenidone for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating chronic fibrotic lung disease. Although the precise cause of the disease is still unknown, recent studies have shown that the pathogenesis of pulmonary fibrosis involves multiple mechanisms, with abnormal behavior of alveolar epithelial cells considered a primary event. Pirfenidone is a multifunctional, orally available small molecule with anti-fibrotic, anti-inflammatory, and antioxidative activities, and has been shown to be a modulator of cytokines and growth factors, including TGF-β1, TNF-α, bFGF, IFN-γ, IL-1β, and IL-18 in animal models. Although its precise mechanism of action is not currently clear, pirfenidone is considered to exert inhibitory effects on multiple pathways involved in the pathogenesis of IPF. Two randomized placebo-controlled clinical trials in Japan demonstrated that pirfenidone significantly reduced the rate of decline of vital capacity in IPF patients. A Phase III study showed a significant increase in progression-free survival of patients in pirfenidone-treated groups compared to the placebo group. These results paved the way for the approval of pirfenidone for the treatment of IPF patients in Japan in 2008. The promising results of the Phase II study in Japan led to a larger international Phase III trial (CAPACITY). Subsequently, pirfenidone has also been approved in the European Union, South Korea, and Canada to date. Pirfenidone treatment is generally tolerated. Major adverse events are gastrointestinal symptoms, including decreased appetite, abdominal discomfort and nausea, photosensitivity, and fatigue, but many of these are mild and manageable. Clinical experience has shown that reduction in pirfenidone dose and the supportive use of gastrointestinal drugs are effective ways to manage these symptoms. Thus, pirfenidone treatment provides a means of intervention in the clinical course of IPF, and is a promising candidate for improving patient prognosis. For future development, it is important to establish the appropriate modality of treatment with pirfenidone and/or novel potential drugs.

Idiopathic Pulmonary Fibrosis – Diagnosis and Treatment

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive irreversible fibrotic lung disease of unknown cause. It occurs in older patients and is limited to the lungs. The prognosis is dismal with a median survival of 3-5 years after diagnosis. The diagnosis is based on a definite pattern of usual interstitial pneumonia on high resolution computed tomography or specific combinations of radiological and histopathological patterns. Early diagnosis and referrral is recommended as anti-fibrotic treatment with pirfenidone or nintedanib that can slow down progression has become available. All patients should be evaluated for lung transplantation.

Matrix regulation of idiopathic pulmonary fibrosis: the role of enzymes

Repairing damaged tissues is an essential homeostatic mechanism that enables clearance of dead or damaged cells after injury, and the maintenance of tissue integrity. However, exaggeration of this process in the lung can lead to the development of fibrotic scar tissue. This is characterized by excessive accumulation of extracellular matrix (ECM) components such as fibronectin, proteoglycans, hyaluronic acid, and interstitial collagens. After tissue injury, or a breakdown of tissue integrity, a cascade of events unfolds to maintain normal tissue homeostasis. Inflammatory mediators are released from injured epithelium, leading to both platelet activation and inflammatory cell migration. Inflammatory cells are capable of releasing multiple pro-inflammatory and fibrogenic mediators such as transforming growth factor (TGF)β and interleukin (IL)-13, which can trigger myofibroblast proliferation and recruitment. The myofibroblast population is also expanded as a result of epithelial cells undergoing epithelial-to-mesenchymal transition and of the activation of resident fibroblasts, leading to ECM deposition and tissue remodeling. In the healthy lung, wound healing then proceeds to restore the normal architecture of the lung; however, fibrosis can develop when the wound is severe, the tissue injury persists, or the repair process becomes dysregulated. Understanding the processes regulating aberrant wound healing and the matrix in the chronic fibrotic lung disease idiopathic pulmonary fibrosis (IPF), is key to identifying new treatments for this chronic debilitating disease. This review focuses primarily on the emerging role of enzymes in the lungs of patients with IPF. Elevated expression of a number of enzymes that can directly modulate the ECM has been reported, and recent data indicates that modulating the activity of these enzymes can have a downstream effect on fibrotic tissue remodeling.

Evidence for a Functional Thymic Stromal Lymphopoietin Signaling Axis in Fibrotic Lung Disease

Thymic stromal lymphopoietin (TSLP) recently has emerged as a key cytokine in the development of type 2 immune responses. Although traditionally associated with allergic inflammation, type 2 responses are also recognized to contribute to the pathogenesis of tissue fibrosis. However, the role of TSLP in the development of non-allergen-driven diseases, characterized by profibrotic type 2 immune phenotypes and excessive fibroblast activation, remains underexplored. Fibroblasts represent the key effector cells responsible for extracellular matrix production but additionally play important immunoregulatory roles, including choreographing immune cell recruitment through chemokine regulation. The aim of this study was to examine whether TSLP may be involved in the pathogenesis of a proto-typical fibrotic disease, idiopathic pulmonary fibrosis (IPF). We combined the immunohistochemical analysis of human IPF biopsy material with signaling studies by using cultured primary human lung fibroblasts and report for the first time, to our knowledge, that TSLP and its receptor (TSLPR) are highly upregulated in IPF. We further show that lung fibroblasts represent both a novel cellular source and target of TSLP and that TSLP induces fibroblast CCL2 release (via STAT3) and subsequent monocyte chemotaxis. These studies extend our understanding of TSLP as a master regulator of type 2 immune responses beyond that of allergic inflammatory conditions and suggest a novel role for TSLP in the context of chronic fibrotic lung disease.

Epidemiology of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a chronic fibrotic lung disease of unknown cause that occurs in adults and has a poor prognosis. Its epidemiology has been difficult to study because of its rarity and evolution in diagnostic and coding practices. Though uncommon, it is likely underappreciated both in terms of its occurrence (ie, incidence, prevalence) and public health impact (ie, health care costs and resource utilization). Incidence and mortality appear to be on the rise, and prevalence is expected to increase with the aging population. Potential risk factors include occupational and environmental exposures, tobacco smoking, gastroesophageal reflux, and genetic factors. An accurate understanding of its epidemiology is important, especially as novel therapies are emerging.