Treatment of idiopathic pulmonary fibrosis with etanercept: an exploratory, placebo-controlled trial

Predicting pulmonary fibrosis disease course from past trends in pulmonary function

BACKGROUND

The clinical course of idiopathic pulmonary fibrosis (IPF) is characterized by progressive decline in lung function and eventual mortality. We sought to determine if future declines in pulmonary function, mortality, or both can be predicted from prior trends in pulmonary function tests (PFTs).

METHODS

Data from 1981 to 2008 on 4,431 PFTs and mortality were analyzed from 734 subjects with IPF. The Kaplan-Meier method was used for mortality analyses. Mixed models were used to describe longitudinal pulmonary function dynamics, since PFTs were observed at varying time points from baseline.

RESULTS

During the first year of follow-up, 135 subjects (73%) had stable FVC while 50 subjects (37%) showed a decline in FVC. During months 12 to 24 (1-2 years after diagnosis), a stable FVC occurred with the same frequency among both subjects whose FVC had declined during year 1 and whose FVC had remained stable (84.0% and 80.7%, respectively; P=.59). Among subjects alive at the end of year 1, those with a stable FVC were more likely to be alive at the end of year 2 than those whose FVC declined (hazard ratio [HR], 0.91 [95% CI, 0.87-0.94] and HR, 0.71 [95% CI, 0.62-0.78], respectively).

CONCLUSIONS

PFT decline predicts early mortality, but not future declines in physiology, regardless of time since diagnosis.

G protein-coupled receptor 56 regulates matrix production and motility of lung fibroblasts

Idiopathic pulmonary fibrosis is a chronic, progressive, and fatal fibrotic lung disease with a poor prognosis, but no effective treatment is available. G protein-coupled receptor 56 (GPR56) plays a role in cell adhesion and tumor progression, but its function in fibrogenesis has not been explored. In this in vitro study, we found that GPR56 in IPF fibroblasts was lower than in normal fibroblasts. GPR56 regulated the production of fibronectin and type I collagen, and also changed the migratory and invasive capacity of lung fibroblasts. However, it was not sufficient to activate some classic markers of fibroblast and myofibroblast, such as α-smooth muscle actin and fibroblast specific protein 1. These findings demonstrate that reduced expression of GPR56 in lung fibroblasts may be an important link with pulmonary fibrosis, playing a role in regulating some important fibroblast functions.

Medical therapy of stricturing Crohn's disease: what the gut can learn from other organs - a systematic review

Crohn’s disease (CD) is a chronic remitting and relapsing disease. Fibrostenosing complications such as intestinal strictures, stenosis and ultimately obstruction are some of its most common long-term complications. Despite recent advances in the pathophysiological understanding of CD and a significant improvement of anti-inflammatory therapeutics, medical therapy for stricturing CD is still inadequate. No specific anti-fibrotic therapy exists and the incidence rate of strictures has essentially remained unchanged. Therefore, the current therapy of established fibrotic strictures comprises mainly endoscopic dilation as well as surgical approaches. However, these treatment options are associated with major complications as well as high recurrence rates. Thus, a specific anti-fibrotic therapy for CD is urgently needed. Importantly, there is now a growing body of evidence for prevention as well as effective medical treatment of fibrotic diseases of other organs such as the skin, lung, kidney and liver. In face of the similarity of molecular mechanisms of fibrogenesis across these organs, translation of therapeutic approaches from other fibrotic diseases to the intestine appears to be a promising treatment strategy. In particular transforming growth factor beta (TGF-β) neutralization, selective tyrosine kinase inhibitors, blockade of components of the renin-angiotensin system, IL-13 inhibitors and mammalian target of rapamycin (mTOR) inhibitors have emerged as potential drug candidates for anti-fibrotic therapy and may retard progression or even reverse established intestinal fibrosis. However, major challenges have to be overcome in the translation of novel anti-fibrotics into intestinal fibrosis therapy, such as the development of appropriate biomarkers that predict the development and accurately monitor therapeutic responses. Future clinical studies are a prerequisite to evaluate the optimal timing for anti-fibrotic treatment approaches, to elucidate the best routes of application, and to evaluate the potential of drug candidates to reach the ultimate goal: the prevention or reversal of established fibrosis and strictures in CD patients.

Disease progression in idiopathic pulmonary fibrosis without pulmonary function impairment

BACKGROUND AND OBJECTIVE

Despite significant recent progress in the understanding of idiopathic pulmonary fibrosis (IPF), the early phase of the disease is still poorly understood. We studied patients with IPF without pulmonary function impairment in order to determine the clinical features, natural history and key findings for physiological progression.

METHODS

Twenty-five patients without pulmonary function impairment were identified from among patients with previously diagnosed IPF who underwent surgical lung biopsies between January 1997 and December 2006 at our institutions. 'Without pulmonary function impairment' was defined as both forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLco) >80% predicted. Patients diagnosed with IPF through multidisciplinary discussion based on the new IPF guidelines were the subjects of this study.

RESULTS

Sixteen patients had a confirmed diagnosis of IPF. Eleven patients presented with chest X-ray abnormality found during an annual health examination. Seven patients were asymptomatic. Eleven patients showed physiological disease progression (median time; 19.9 ± 12.3 months) defined by a decline of at least 10% in FVC or at least 15% in DLco. Univariate analysis revealed that both usual interstitial pneumonia pattern and extent of honeycombing on high-resolution computed tomography (HRCT) were factors associated with disease progression (odds ratio 5.634, 95% confidence interval 1.364-23.278; odds ratio 2.371/5%, 95% confidence interval 1.042-5.395).

CONCLUSIONS

IPF patients without pulmonary function impairment have a progressive but slow clinical course. The existence and extent of honeycombing on HRCT are predictive of disease progression.

The treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and invariably fatal disease with a median survival of less than three years from diagnosis. The last decade has seen an exponential increase in clinical trial activity in IPF and this in turn has led to important developments in the treatment of this terrible disease. Previous therapeutic approaches based around regimens including corticosteroids and azathioprine have, when tested in randomized clinical trials, been shown to be harmful in IPF. By contrast, compounds with anti-fibrotic actions have been shown to be beneficial. Subsequently, the novel anti-fibrotic agent pirfenidone has, in many parts of the world, become the first treatment ever to be licensed for use in IPF. This exciting development, coupled with ongoing clinical trials of a range of other novel compounds, is bringing hope to patients and their clinicians and raises the prospect that, in the future, it may become possible to successfully arrest the development of progressive scarring in IPF.

[Idiopathic pulmonary fibrosis: diagnosis and treatment in 2013]

Idiopathic pulmonary fibrosis (IPF), the etiopathogeny of which is still unknown, is the most frequent and severe of idiopathic interstitial pneumonias. It progressively leads, sometimes more acutely when exacerbations occur, to a restrictive respiratory insufficiency. Its prognosis is very dark with a median survival of 3-5 years. No treatment so far has been curative. Its diagnostic and therapeutic management has been greatly improved due to the technical progress in terms of high-resolution tomodensitometry, to the availability of new drugs with a real antifibrotic potential and to the production of international recommendations. The diagnosis is reached in 2/3 of IPF patients presenting with a typical usual interstitial pneumonitis (UIP) CT-scan pattern. It requires a videothoracoscopic biopsy in the remaining patients. Multidisciplinary discussions are key to a proper diagnosis of IPF. Pirfenidone is presently the only drug with a real antifibrotic potential in mild to moderate forms of the disease (FVC>50% and DLCO>35% predicted). The other ones have proved either inefficient or toxic. It is highly recommended to include patients in innovative targeted protocols. Non-pharmacological management of these patients comprises long-term oxygen therapy, pulmonary rehabilitation and overall lung transplantation. Pulmonary hypertension, to be detected regularly during the follow-up, is associated to a dark prognosis. No specific treatment is efficient in this context. Several comorbidities, particularly frequent in IPF, should be treated when present: gastro-oesophageal reflux, obstructive sleep apnea, emphysema. The particular high frequency of bronchopulmonary cancer should be highlighted.

High-resolution CT scoring system-based grading scale predicts the clinical outcomes in patients with idiopathic pulmonary fibrosis

BACKGROUND

The 2011 idiopathic pulmonary fibrosis (IPF) guidelines are based on the diagnosis of IPF using only high-resolution computed tomography (HRCT). However, few studies have thus far reviewed the usefulness of the HRCT scoring system based on the grading scale provided in the guidelines. We retrospectively studied 98 patients with respect to assess the prognostic value of changes in HRCT findings using a new HRCT scoring system based on the grading scale published in the guidelines.

METHODS

Consecutive patients with IPF who were diagnosed using HRCT alone between January 2008 and January 2012 were evaluated. HRCT examinations and pulmonary function tests were performed at six-month intervals for the first year after diagnosis. The HRCT findings were evaluated using the new HRCT scoring system (HRCT fibrosis score) over time. The findings and survival rates were analyzed using a Kaplan-Meier analysis.

RESULTS

The HRCT fibrosis scores at six and 12 months after diagnosis were significantly increased compared to those observed at the initial diagnosis (p < 0.001). The patients with an elevated HRCT fibrosis score at six months based on a receiver operating characteristic (ROC) curves analysis had a poor prognosis (log-rank, hazard ratio [HR] 2.435, 95% CI 1.196-4.962; p = 0.0142). Furthermore, among the patients without marked changes in %FVC, those with an elevated score above the cut-off value had a poor prognosis (HR 2.192, 95% CI 1.003-4.791; p = 0.0491).

CONCLUSIONS

Our data demonstrate that the HRCT scoring system based on the grading scale is useful for predicting the clinical outcomes of IPF and identifying patients with an adverse prognosis when used in combination with spirometry.

The safety of biologic therapies in RA-associated interstitial lung disease

Interstitial lung disease (ILD) is a common extra-articular manifestation associated with increased morbidity and mortality in patients with rheumatoid arthritis (RA). Early case reports of serious respiratory adverse events (SRAEs) following treatment with anti-TNF agents have led to concerns about biologic therapy in patients with RA-associated ILD (RA-ILD), and a tendency for biologic agents targeting factors other than TNF to be prescribed in such patients. At present, the appropriateness of such decisions is not clear. Given that the therapeutic goal for RA is remission, clinicians increasingly face the challenge of choosing the optimal biologic agent in patients with RA-ILD and uncontrolled joint disease. However, no evidence-based guidelines exist to guide physicians in deciding whether to commence biologic therapy in this setting, or in selecting which drug is most appropriate. Herein, we review the evidence for the comparative pulmonary safety of anti-TNF agents and non-TNF-targeting biologic agents in RA-ILD. In addition, we propose a framework for assessment of baseline disease severity to guide treatment decisions, and for monitoring during therapy. Because of substantial gaps in the available evidence, we also describe a research agenda aimed at obtaining data that will help inform future clinical practice.

Effects of leflunomide on inflamation and fibrosis in bleomycine induced pulmonary fibrosis in wistar albino rats

PURPOSES

Pulmonary fibrosis is a rare and progressive lung disease with a high mortality rate. The treatment regimens still fail to recover the disease. Leflunomide (LEF) is an immunomodulatory agent with antiproliferative activity that is used for the treatment of rheumatoid arthritis. The purpose of the study is to investigate the potential therapeutic efficacy of LEF in bleomycin (BLM) induced pulmonary fibrosis.

METHODS

A total of 21 male, adult wistar albino rats were used. The animals were divided into three groups as control, BLM and BLM plus LEF groups (n=7). In BLM group, mice were treated with intratracheal instillation of BLM (2.5 U/kg). Control group received the same volume of saline instead of BLM. In LEF group, in addition to BLM, LEF (10 mg/kg, daily) was administrated by oral gavage. The effect of LEF on pulmonary inflammation and fibrosis was studied by measurements of serum clara cell protein-16 (CC-16), thiobarbituric acid reactive substance levels (TBARS), superoxide dismutase (SOD) and advanced oxidation protein products (AOPP) levels and lung tissue contents of IL-6, TNF-α and NF-κB by immunhistochemical examinations.

RESULTS

LEF significantly increased the level of CC-16 and decreased the level of AOPP (P=0.042 and P=0.003 respectively). Lung tissue contents of IL-6, TNF-α and NF-κB significantly decreased in LEF group compared to BLM group by immunhistochemical examinations (P<0.001).

CONCLUSIONS

LEF reduces oxidative stress factors, alveolar inflammation and attenuates lung injury and fibrosis.

Hepatocyte growth factor is an attractive target for the treatment of pulmonary fibrosis

INTRODUCTION

Pulmonary fibrosis (PF) is a progressive fatal disorder and is characterized by alveolar epithelial injury, myofibroblast proliferation, and extracellular matrix remodeling, resulting in irreversible distortion of lung's architecture. Available therapies are associated with side effects and show restricted efficacy. Therefore, there is an urgent need to find a therapeutic solution to PF. Therapeutic strategies interfering myofibroblast expansion, apoptosis of epithelial and endothelial cells might be beneficial for treatment of PF. Hepatocyte growth factor (HGF), a pleiotropic growth factor, plays an important role in lung development, inflammation, repair, and regeneration. In animal model of PF, administration of recombinant HGF protein or ectopic HGF expression ameliorates fibrosis.

AREAS COVERED

The focus of this review is to highlight HGF as a promising therapeutic approach for the treatment of PF. The review discusses the currently available treatment option for PF as well as highlights the possible beneficial effect of HGF as a drug target.

EXPERT OPINION

HGF with its anti-fibrotic effect provides a promising new therapeutic approach by protecting lung from fibrotic remodeling and also promoting normal regeneration of lung. The development of HGF mimetics may provide a potential attractive therapy for treatment of this devastating and complex disease.

Human amnion epithelial cells do not abrogate pulmonary fibrosis in mice with impaired macrophage function

Since current treatments for both acute and chronic lung diseases are less than ideal, there has been recent interest in the use of cell-based therapies for inflammatory lung disease. Specifically, human amnion epithelial cells (hAECs) have been shown to reduce bleomycin-induced lung injury and prevent subsequent loss of respiratory function, primarily through modulation of the host immune response. The precise mechanisms of this effect remain unclear. We aimed to investigate the potential of hAECs to mitigate bleomycin-induced lung injury in surfactant protein C deficient (Sftpc(−/−)) mice, which are highly susceptible to pulmonary injury as a result of impairment of macrophage function. Primary hAECs were administered to wild-type (Sftpc(+/+)) and Sftpc(−/−) mice 24 h after exposure to bleomycin. Compared to Sftpc(+/+) mice receiving bleomycin alone, Sftpc(+/+) mice administered hAECs 24 h after bleomycin exposure had decreased expression of proinflammatory genes, decreased macrophage and neutrophil infiltration, fibrosis, collagen content, and α-smooth muscle actin as well as a significant improvement in lung function. Compared to Sftpc(−/−) mice given bleomycin alone, Sftpc(−/−) mice administered hAECs 24 h after bleomycin did not have a decrease in inflammatory gene expression or a reduction in macrophage pulmonary infiltration. Subsequently, Sftpc(−/−) mice did not show any decrease in pulmonary fibrosis or improvement of lung function after hAEC administration. The ability of hAECs to mitigate bleomycin-induced lung injury is abolished in Sftpc(−/−) mice, suggesting that hAECs require normal host macrophage function to exert their reparative effects.

Cytokine mediated tissue fibrosis

Acute inflammation is a recognised part of normal wound healing. However, when inflammation fails to resolve and a chronic inflammatory response is established this process can become dysregulated resulting in pathological wound repair, accumulation of permanent fibrotic scar tissue at the site of injury and the failure to return the tissue to normal function. Fibrosis can affect any organ including the lung, skin, heart, kidney and liver and it is estimated that 45% of deaths in the western world can now be attributed to diseases where fibrosis plays a major aetiological role. In this review we examine the evidence that cytokines play a vital role in the acute and chronic inflammatory responses that drive fibrosis in injured tissues. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

Always cleave up your mess: targeting collagen degradation to treat tissue fibrosis

Pulmonary fibrosis is a vexing clinical problem with no proven therapeutic options. In the normal lung there is continuous collagen synthesis and collagen degradation, and these two processes are precisely balanced to maintain normal tissue architecture. With lung injury there is an increase in the rate of both collagen production and collagen degradation. The increase in collagen degradation is critical in preventing the formation of permanent scar tissue each time the lung is exposed to injury. In pulmonary fibrosis, collagen degradation does not keep pace with collagen production, resulting in extracellular accumulation of fibrillar collagen. Collagen degradation occurs through both extracellular and intracellular pathways. The extracellular pathway involves cleavage of collagen fibrils by proteolytic enzyme including the metalloproteinases. The less-well-described intracellular pathway involves binding and uptake of collagen fragments by fibroblasts and macrophages for lysosomal degradation. The relationship between these two pathways and their relevance to the development of fibrosis is complex. Fibrosis in the lung, liver, and skin has been associated with an impaired degradative environment. Much of the current scientific effort in fibrosis is focused on understanding the pathways that regulate increased collagen production. However, recent reports suggest an important role for collagen turnover and degradation in regulating the severity of tissue fibrosis. The objective of this review is to evaluate the roles of the extracellular and intracellular collagen degradation pathways in the development of fibrosis and to examine whether pulmonary fibrosis can be viewed as a disease of impaired matrix degradation rather than a disease of increased matrix production.

Pathogenesis, current treatments and future directions for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease (ILD) of unknown origin characterized by epithelial cell dysfunctions, accumulation of fibroblasts and myofibroblasts and relentless deposition of extracellular matrix (ECM). Improved diagnostic accuracy and better trial design have provided important insights from recent clinical trials. Perhaps the most important insight was the realization that 'standard therapy' was actually harmful! This review summarizes the current understanding of the cell types that are altered in IPF and the pathogenic mechanisms that have been identified. It also reviews recent clinical trial results and interpretations. Finally, we highlight attractive biologic targets and therapies in development with recommendations for future therapeutic avenues.

Evolving therapies for liver fibrosis

Fibrosis is an intrinsic response to chronic injury, maintaining organ integrity when extensive necrosis or apoptosis occurs. With protracted damage, fibrosis can progress toward excessive scarring and organ failure, as in liver cirrhosis. To date, antifibrotic treatment of fibrosis represents an unconquered area for drug development, with enormous potential but also high risks. Preclinical research has yielded numerous targets for antifibrotic agents, some of which have entered early-phase clinical studies, but progress has been hampered due to the relative lack of sensitive and specific biomarkers to measure fibrosis progression or reversal. Here we focus on antifibrotic approaches for liver that address specific cell types and functional units that orchestrate fibrotic wound healing responses and have a sound preclinical database or antifibrotic activity in early clinical trials. We also touch upon relevant clinical study endpoints, optimal study design, and developments in fibrosis imaging and biomarkers.

The current position of surgical lung biopsy in the diagnosis of idiopathic pulmonary fibrosis

A new international statement defines usual interstitial pneumonia (UIP) which is a histological and radiological form of idiopathic pulmonary fibrosis (IPF) more precisely than previously. In the diagnosis of IPF, either in high resolution computed tomography (HRCT) a UIP pattern must be present or alternatively specific combinations of HRCT and surgical lung biopsy findings can be accepted. In about two third of the cases IPF can be diagnosed by clinical and radiological criteria. Thus surgical lung biopsy is needed in about one third of cases to achieve the ultimate diagnosis, which requires multidisciplinary cooperation. In large clinical trials conducted during the last decade, lung biopsy was performed in about 30-60% of the cases. The most serious complication of lung biopsy is mortality within 30 days after the procedure, with a frequency of about 3-4% reported in most studies. Because of the histological variability, surgical lung biopsy should be taken from a minimum of two lobes. The number of fibroblast foci in surgical lung biopsy has been shown to correlate with survival in several studies.

Acute exacerbation of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive and ultimately fatal disease, the clinical course of which in individual patients is highly variable. Sudden deterioration of a patient's respiratory condition during a stable course is not uncommon. Many cases of uncertain etiology have been called acute exacerbation (AEx) of IPF, under the assumption of sudden acceleration of the underlying disease process. In recent years, several studies have reported the clinical significance of AEx-IPF. In 2007 Collard and colleagues created a Consensus Perspective, which proposed consensus definition and standard diagnostic criteria. This review primarily discusses studies performed after this Consensus Perspective.

A review of current and novel therapies for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressively fibrotic interstitial lung disease that is associated with a median survival of 2-3 years from initial diagnosis. To date, there is no treatment approved for IPF in the United States, and only one pharmacological agent has been approved outside of the United States. Nevertheless, research over the past 10 years has provided us with a wealth of information on its histopathology, diagnostic work-up, and a greater understanding of its pathophysiology. Specifically, IPF is no longer thought to be a predominantly pro-inflammatory disorder. Rather, the fibrosis in IPF is increasingly understood to be the result of a fibroproliferative and aberrant wound healing cascade. The development of therapeutic targets has shifted in accord with this paradigm change. This review highlights the current understanding of IPF, and the recent as well as novel therapeutics being explored in clinical trials for the treatment of this devastating disease.

Patient-reported outcomes in idiopathic pulmonary fibrosis research

Patient-reported outcomes (PROs) include questionnaires or surveys that ask patients for their perceptions about things like symptoms they are experiencing or quality of life. For incurable, morbid, life-shortening conditions like idiopathic pulmonary fibrosis (IPF), PROs are particularly germane: They elucidate for clinicians and researchers what it is like for patients to live with such a disease, and they may detect important treatment effects not captured by other metrics (eg, pulmonary physiology). However, a relative paucity of research on PROs in IPF has left significant knowledge gaps in this area and contributed to the timidity investigators have about using PROs as prominent outcomes in IPF drug trials. Additional research on existing instruments is needed to establish or bolster their basic psychometric properties in IPF. When PROs are used as end points in therapeutic trials, analyzing PRO response data can be challenging, but these challenges can be overcome with a transparent, thoughtful, and sophisticated statistical approach. In this article, we discuss some of the basics of PRO assessment, existing knowledge gaps in IPF-related PRO research, and the potential usefulness of using PROs in IPF trials and conclude by offering specific recommendations for an approach to analyzing repeated-measures PRO data from IPF trials.

Monitoring of nonsteroidal immunosuppressive drugs in patients with lung disease and lung transplant recipients: American College of Chest Physicians evidence-based clinical practice guidelines

OBJECTIVES

Immunosuppressive pharmacologic agents prescribed to patients with diffuse interstitial and inflammatory lung disease and lung transplant recipients are associated with potential risks for adverse reactions. Strategies for minimizing such risks include administering these drugs according to established, safe protocols; monitoring to detect manifestations of toxicity; and patient education. Hence, an evidence-based guideline for physicians can improve safety and optimize the likelihood of a successful outcome. To maximize the likelihood that these agents will be used safely, the American College of Chest Physicians established a committee to examine the clinical evidence for the administration and monitoring of immunosuppressive drugs (with the exception of corticosteroids) to identify associated toxicities associated with each drug and appropriate protocols for monitoring these agents.

METHODS

Committee members developed and refined a series of questions about toxicities of immunosuppressives and current approaches to administration and monitoring. A systematic review was carried out by the American College of Chest Physicians. Committee members were supplied with this information and created this evidence-based guideline.

CONCLUSIONS

It is hoped that these guidelines will improve patient safety when immunosuppressive drugs are given to lung transplant recipients and to patients with diffuse interstitial lung disease.

Pirfenidone: significant treatment effects in idiopathic pulmonary fibrosis

Pirfenidone has been shown in three recently published trials to slow down the progression of the devastating interstitial lung disease, idiopathic pulmonary fibrosis (IPF). The precise mechanisms that initiate and perpetuate the histopathological process leading to lung fibrosis in IPF are still uncertain, but increased concentrations of reactive oxidative species and fibrogenetic factors have been observed in the pulmonary tissue of patients. Although the exact mechanisms of its action are unknown, pirfenidone is a small molecule with antifibrotic and some hydroxyl scavenger properties that has recently been approved in Europe and elsewhere for the treatment of IPF. Along with the new ATS/ERS/JRS/ALAT 2011 statement for 'Evidence Based Guidelines for Diagnosis and Management', there is now a more profound basis for offering IPF patients an evidence-based evaluation and treatment. This review summarizes the background to the recommended use of pirfenidone for the treatment of IPF.

Host responses in tissue repair and fibrosis

Myofibroblasts accumulate in the spaces between organ structures and produce extracellular matrix (ECM) proteins, including collagen I. They are the primary "effector" cells in tissue remodeling and fibrosis. Previously, leukocyte progenitors termed fibrocytes and myofibroblasts generated from epithelial cells through epithelial-to-mesenchymal transition (EMT) were considered the primary sources of ECM-producing myofibroblasts in injured tissues. However, genetic fate mapping experiments suggest that mesenchyme-derived cells, known as resident fibroblasts, and pericytes are the primary precursors of scar-forming myofibroblasts, whereas epithelial cells, endothelial cells, and myeloid leukocytes contribute to fibrogenesis predominantly by producing key fibrogenic cytokines and by promoting cell-to-cell communication. Numerous cytokines derived from T cells, macrophages, and other myeloid cell populations are important drivers of myofibroblast differentiation. Monocyte-derived cell populations are key regulators of the fibrotic process: They act as a brake on the processes driving fibrogenesis, and they dismantle and degrade established fibrosis. We discuss the origins, modes of activation, and fate of myofibroblasts in various important fibrotic diseases and describe how manipulation of macrophage activation could help ameliorate fibrosis.

Adverse events of pirfenidone for the treatment of pulmonary fibrosis: a meta-analysis of randomized controlled trials

Background

Pirfenidone (PFD) is a novel antifibrotic agent approved for patients with pulmonary fibrosis. However, there are concerns regarding toxicity of the drug. In this meta-analysis, we analyzed the adverse events (AEs) of PFD for the treatment of pulmonary fibrosis.

Methods

We performed a systematic search of PubMed, Embase, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials for trials published between January 1999 and October 2011. Data extracted from literature were analyzed with Review manager 5.0.24.

Results

The results of six randomized controlled trials (1073 participants) revealed that the number of individuals who discontinued PFD therapy was significantly higher than patients receiving placebo. The PFD group had a significantly higher rate of gastrointestinal (nausea, dyspepsia, diarrhea, and anorexia), neurological (dizziness and fatigue), and dermatological (photosensitivity and rash) AEs compared to the placebo group.

Conclusions

PFD used for the treatment of pulmonary fibrosis is not so safe or well-tolerated. Notably, gastrointestinal, neurological and dermatological adverse effects were more common in patients receiving PFD therapy, and therefore appropriate precaution is needed.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease of unknown cause characterized by progressive scarring of the lung parenchyma and relentless loss of lung function. The diagnosis depends on close collaboration between clinicians, radiologists, and pathologists. No therapies approved by the Food and Drug Administration are available for IPF, and an analysis of completed clinical trials has demonstrated that the clinical course of IPF is largely unpredictable. Until therapies that improve survival become available, measures to preserve function and quality of life should be considered, and gastroesophageal reflux should be treated aggressively.

Molecular and cellular mechanisms of pulmonary fibrosis

Pulmonary fibrosis is a chronic lung disease characterized by excessive accumulation of extracellular matrix (ECM) and remodeling of the lung architecture. Idiopathic pulmonary fibrosis is considered the most common and severe form of the disease, with a median survival of approximately three years and no proven effective therapy. Despite the fact that effective treatments are absent and the precise mechanisms that drive fibrosis in most patients remain incompletely understood, an extensive body of scientific literature regarding pulmonary fibrosis has accumulated over the past 35 years. In this review, we discuss three broad areas which have been explored that may be responsible for the combination of altered lung fibroblasts, loss of alveolar epithelial cells, and excessive accumulation of ECM: inflammation and immune mechanisms, oxidative stress and oxidative signaling, and procoagulant mechanisms. We discuss each of these processes separately to facilitate clarity, but certainly significant interplay will occur amongst these pathways in patients with this disease.

Treatment of idiopathic pulmonary fibrosis with losartan: a pilot project

BACKGROUND

Idiopathic pulmonary fibrosis is a progressive interstitial lung disease with no current effective therapies. Treatment has focused on antifibrotic agents to stop proliferation of fibroblasts and collagen deposition in the lung. We present the first clinical trial data on the use of losartan, an antifibrotic agent, to treat idiopathic pulmonary fibrosis. The primary objective was to evaluate the effect of losartan on progression of idiopathic pulmonary fibrosis measured by the change in percentage of predicted forced vital capacity (%FVC) after 12 months. Secondary outcomes included the change in forced expiratory volume at 1 second, diffusing capacity of carbon monoxide, 6-minute walk test distance, and baseline/transition dyspnea index.

METHODS

Patients with idiopathic pulmonary fibrosis and a baseline %FVC of ≥50 % were treated with losartan 50 mg by mouth daily for 12 months. Pulmonary function testing, 6-minute walk, and breathlessness indices were measured every 3 months.

RESULTS

Twenty participants with idiopathic pulmonary fibrosis were enrolled and 17 patients were evaluable for response. Twelve patients had a stable or improved %FVC at study month 12. Similar findings were observed in secondary end-point measures, including 58, 71, and 65 % of patients with stable or improved forced expiratory volume at 1 second, diffusing capacity for carbon monoxide, and 6-minute walk test distance, respectively. No treatment-related adverse events that resulted in early study discontinuation were reported.

CONCLUSION

Losartan stabilized lung function in patients with idiopathic pulmonary fibrosis over 12 months. Losartan is a promising agent for the treatment of idiopathic pulmonary fibrosis and has a low toxicity profile.

Mechanisms of fibrosis: therapeutic translation for fibrotic disease

Fibrosis is a pathological feature of most chronic inflammatory diseases. Fibrosis, or scarring, is defined by the accumulation of excess extracellular matrix components. If highly progressive, the fibrotic process eventually leads to organ malfunction and death. Fibrosis affects nearly every tissue in the body. Here we discuss how key components of the innate and adaptive immune response contribute to the pathogenesis of fibrosis. We also describe how cell-intrinsic changes in important structural cells can perpetuate the fibrotic response by regulating the differentiation, recruitment, proliferation and activation of extracellular matrix-producing myofibroblasts. Finally, we highlight some of the key mechanisms and pathways of fibrosis that are being targeted as potential therapies for a variety of important human diseases.

Mechanisms of fibrosis: therapeutic translation for fibrotic disease

Fibrosis is a pathological feature of most chronic inflammatory diseases. Fibrosis, or scarring, is defined by the accumulation of excess extracellular matrix components. If highly progressive, the fibrotic process eventually leads to organ malfunction and death. Fibrosis affects nearly every tissue in the body. Here we discuss how key components of the innate and adaptive immune response contribute to the pathogenesis of fibrosis. We also describe how cell-intrinsic changes in important structural cells can perpetuate the fibrotic response by regulating the differentiation, recruitment, proliferation and activation of extracellular matrix-producing myofibroblasts. Finally, we highlight some of the key mechanisms and pathways of fibrosis that are being targeted as potential therapies for a variety of important human diseases.

Fibrocytes and the pathogenesis of diffuse parenchymal lung disease

Fibrosis is fundamental to the pathogenesis of many chronic lung diseases, including some lung infections, airway diseases such as bronchiectasis and asthma, and most of the diffuse parenchymal lung diseases. Idiopathic pulmonary fibrosis, the prototypical fibrotic lung disease, is amongst the most common diffuse parenchymal lung diseases and is characterized by progressive decline in lung function and premature death from respiratory failure. The clinical management of patients with this illness is hampered by our current inability to predict clinical deterioration and lack of an effective therapy. Fibrocytes are a population of bone marrow-derived circulating progenitor cells that home to injured tissues and differentiate into fibroblasts and myofibroblasts, thus contributing to scar formation. We summarize the evidence supporting the role of these cells in the pathogenesis of fibrotic lung diseases.

Health-related quality of life and 6 min walk distance in patients with idiopathic pulmonary fibrosis

BACKGROUND

Few studies have investigated the relationship between physiological outcomes and quality of life in patients with idiopathic pulmonary fibrosis (IPF). Health-related quality of life (HRQL) data may provide a valuable patient-centred outcome for the evaluation of interventions. Determination of which physiological and functional variables are associated with HRQL may facilitate interpretation of disease progression and impacts of therapy.

OBJECTIVES

To determine whether an association between Medical Outcomes Short-Form 36 and St George's Respiratory Questionnaire scores and other markers of disease severity exist, and to identify which physiological and functional variables are independently associated with HRQL.

METHODS

In a cross-sectional study, 137 patients with IPF completed HRQL surveys and underwent clinical assessment. Multiple linear regression analysis was used to determine the relationship between age, forced vital capacity, diffusing capacity of carbon monoxide, 6 min walk distance (6MWD) and oxygen requirement, and HRQL scores.

RESULTS

6MWD was the only functional measure of disease severity significantly associated with all domain scores of the St George's Respiratory Questionnaire and the Medical Outcomes Short-Form 36 physical component summary score.

CONCLUSIONS

6MWD was associated with HRQL among patients with IPF. This highlights the importance of 6MWD not only as a prognostic indicator in IPF, but also a predictor of HRQL and a meaningful outcome for patients.

Prednisone, azathioprine, and N-acetylcysteine for pulmonary fibrosis

BACKGROUND

A combination of prednisone, azathioprine, and N-acetylcysteine (NAC) has been widely used as a treatment for idiopathic pulmonary fibrosis. The safety and efficacy of this three-drug regimen is unknown.

METHODS

In this randomized, double-blind, placebo-controlled trial, we assigned patients with idiopathic pulmonary fibrosis who had mild-to-moderate lung-function impairment to one of three groups -- receiving a combination of prednisone, azathioprine, and NAC (combination therapy), NAC alone, or placebo -- in a 1:1:1 ratio. The primary outcome was the change in longitudinal measurements of forced vital capacity during a 60-week treatment period.

RESULTS

When approximately 50% of data had been collected (with 77 patients in the combination-therapy group and 78 in the placebo group), a planned interim analysis revealed that patients in the combination-therapy group, as compared with the placebo group, had an increased rate of death (8 vs. 1, P=0.01) and hospitalization (23 vs. 7, P<0.001). These observations, coupled with no evidence of physiological or clinical benefit for combination therapy, prompted the independent data and safety monitoring board to recommend termination of the combination-therapy group at a mean follow-up of 32 weeks. Data from the ongoing comparison of the NAC-only group and the placebo group are not reported here.

CONCLUSIONS

Increased risks of death and hospitalization were observed in patients with idiopathic pulmonary fibrosis who were treated with a combination of prednisone, azathioprine, and NAC, as compared with placebo. These findings provide evidence against the use of this combination in such patients. (Funded by the National Heart, Lung, and Blood Institute and the Cowlin Family Fund; ClinicalTrials.gov number, NCT00650091.).

[Treatment of pulmonary fibrosis. New substances and new interventions]

Idiopathic pulmonary fibrosis is a chronic progressive lung disease with poor prognosis. The IFIGENIA trial showed that antioxidative therapy with N-acetylcysteine versus placebo for patients under treatment with prednisone plus azathioprine significantly slowed the deterioration of pulmonary function after 12 months. A number of other drugs have recently been evaluated in large multicenter placebo-controlled trials. Etanercept, interferon-γ, bosentan, ambrisentan, imatinib, and sildenafil did not show efficacy. The antifibrotic active ingredient pirfenidone is the first drug approved for the treatment of adult patients with mild to moderate idiopathic pulmonary fibrosis in the European Union. Approval was based on the results of 4 randomized, placebo-controlled clinical trials including more than 1,100 patients. Pirfenidone slowed the decline in lung function and reduced the risk of disease progression. Side effects include gastrointestinal discomfort, skin reactions, including photosensitivity, and rarely increased liver enzymes.

Idiopathic pulmonary fibrosis is associated with circulating antiepithelial antibodies

PURPOSE

Idiopathic pulmonary fibrosis (IPF) is a restrictive fibrotic lung disease of uncertain etiology. Alveolar epithelial injury may be one of the inciting triggers in the pathogenesis of this disorder. We hypothesized that circulating antibodies to alveolar epithelial and endothelial cells may be involved in the pathogenesis of IPF.

METHODS

Antibodies to alveolar epithelial and endothelial cells were analyzed by indirect immunofluorescence using alveolar epithelial cells (A549) and human umbilical vein endothelial cells respectively. IgG and IgM antibodies in patients' serum were evaluated. Patterns of immunofluorescence, including membranous, cytoplasmic, and nuclear staining, were analyzed by fluorescence microscopy. The severity of immunofluorescence was divided into mild, moderate, and severe categories. Fifty-six patients (IPF = 28, non-IPF ILD = 9, non-ILD control = 19) were evaluated for antiepithelial antibodies, and 28 patients (IPF = 12, non-IPF ILD = 3, non-ILD control = 13) were studied for antiendothelial antibodies.

RESULTS

Compared with control subjects, serum from IPF patients displayed significantly higher IgG binding to alveolar epithelial cells (P = 0.041) with a membranous pattern of immunofluorescence. However, there was no significant difference in immunofluorescence with IgG on endothelial cells (P = 0.165). In terms of IgM antibodies, there was no differential fluorescence observed for either epithelial or endothelial cells.

CONCLUSIONS

There is evidence of increased IgG antibodies directed against alveolar epithelium in IPF. These antibodies may play a significant role in the pathogenesis of this fibrotic disorder. The findings of this study suggest further evaluation of the role of immune mediated alveolar epithelial injury in IPF.

Dyspnea in idiopathic pulmonary fibrosis: a systematic review

CONTEXT

Little is known about the treatment and correlates of dyspnea in idiopathic pulmonary fibrosis (IPF).

OBJECTIVES

The objective of this systematic review was to summarize the literature regarding the treatment and correlates of dyspnea in IPF.

METHODS

MEDLINE, EMBASE, and all Evidence-Based Medicine Reviews were searched for publications that evaluated treatment or correlates of dyspnea in IPF. Reference lists and recent review articles also were searched.

RESULTS

The heterogeneity of included studies did not permit meta-analysis. Dyspnea improved in studies of sildenafil, pulmonary rehabilitation, and prednisone with colchicine. Additional studies of these three treatments, however, found discordant results. One study suggested that assisted ventilation delivered by facemask improved exertional dyspnea. Oxygen and opioids improve dyspnea in other chronic lung diseases, but data in IPF are limited. Correlates of dyspnea included functional and physiological measures and comorbid diseases.

CONCLUSION

Sildenafil and pulmonary rehabilitation should be considered as potential therapies for dyspnea in selected patients with IPF. Supplemental oxygen and opioids may be additional potential therapies; however, the evidence supporting their use is weak. Additional research should focus on the management of functional status and comorbidities as potential treatments for dyspnea.

New insights into the pathogenesis and treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common and lethal of the idiopathic interstitial pneumonias. There are currently no effective pharmacological therapies approved for the treatment of IPF. Despite the focus on targeting fibrogenic pathways, recent clinical trials have been largely disappointing. Progress is being made in elucidating key cellular processes and molecular pathways critical to IPF pathogenesis, and this should facilitate the development of more effective therapeutics for this recalcitrant disease. Emerging pathobiological concepts include the role of aging and cellular senescence, oxidative stress, endoplasmic reticulum stress, cellular plasticity, microRNAs and mechanotransduction. Therapeutic approaches that target molecular pathways to modulate aberrant cellular phenotypes and promote tissue homeostasis in the lung must be developed. Heterogeneity in biological and clinical phenotypes of IPF warrants a personalized medicine approach to diagnosis and treatment of this lung disorder.

Newer modes of treating interstitial lung disease

PURPOSE OF REVIEW

This review critically discusses recent advances in the treatment of idiopathic pulmonary fibrosis (IPF). Moreover, it also focuses on the practical approach of a patient diagnosed with IPF and uncovers challenges for the future.

RECENT FINDINGS

Treatment can be divided into three major parts. Firstly, many new agents have been tested, but only the combination of N-acetylcysteine with corticosteroids, azathioprine and pirfenidone was able to show some significant effects. In the mean time, many second-generation agents are under development. Lung transplantation has made some major progress by introducing an appropriate allocation system. Finally, as part of best supportive care, several studies show that pulmonary rehabilitation might induce some important effects on quality of life.

SUMMARY

So, it is clear that major progress has been made in the treatment of IPF, but we are convinced that an orchestrated effort will lead to a better understanding and treatment of this devastating condition.

Biological treatments and connective tissue disease associated interstitial lung disease

PURPOSE OF REVIEW

There is no specific therapy for interstitial lung disease associated with connective tissue diseases (CTDs-ILD), a potentially fatal condition for some of these patients. This article reviews currently available information on the effects on CTDs-ILD of biological treatments that are increasingly used with considerable success in various systemic diseases.

RECENT FINDINGS

A beneficial effect of antitumor necrosis factor (TNF) agents on CTDs-ILD has been described in sporadic patients with rheumatoid arthritis (RA), systemic sclerosis (SSc) and systemic lupus erythematosus (SLE). However, and despite the fact that there was no clear evidence of pulmonary toxicity of these agents in randomized-controlled trials comprising thousands of patients with RA and spondylarthropathies, new onset or exacerbation of preexisting ILD with high mortality rates has so far been observed in 144 RA patients following anti-TNF treatment in clinical practice. Likewise, administration of the B-cell depleting anti-CD20 antibody rituximab was beneficial for ILD in SSc patients but associated with new-onset ILD in isolated patients with RA and SLE. Pertinent information on other biological treatments is currently lacking.

SUMMARY

Data on the therapeutic role of biological agents in CTDs-ILD is preliminary and controversial. Although preexisting ILD is not a contraindication for these agents, until more information is available their administration should be stopped when new pulmonary symptoms occur.

Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a specific clinicopathologic ­syndrome presenting in older adults with the predominant features: dyspnea, dry cough, restrictive defect on pulmonary function tests (PFTs), hypoxemia, characteristic abnormalities on high-resolution thin section computed tomographic (HRCT) scans, usual interstitial pneumonitis (UIP) pattern on lung biopsy. Surgical lung biopsy is the gold standard of diagnosis, but the diagnosis can be established in some cases by HRCT, provided the clinical features are consistent. The cause of IPF is unknown. However, IPF is more common in adults >60 years old, smokers (current or ex), and patients with specific occupational or noxious exposures. Familial IPF, associated with several distinct genetic mutations, accounts for 1.5–3% of cases. Unfortunately, the prognosis is poor, and most patients die of respiratory failure within 3–6 years of diagnosis. However, the course is highly variable. In some patients, the disease is fulminant, progressing to lethal respiratory failure within months, whereas the course may be indolent, spanning >5 years in some patients. Therapy has not been proven to alter the course of the disease or influence mortality, but recent studies with pirfenidone and tyrosine kinase inhibitors are promising. Lung transplantation is the best therapeutic option, but is limited to selected patients with severe, life-threatening disease and no contraindications to transplant.

Management of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a deadly progressive lung disease without an effective standard treatment approach. Because of the complexity and uncertainties of IPF treatment, therapeutic decisions need to be tailored to the individual patient, after discussing the potential benefits and pitfalls. Pirfenidone has been approved for the treatment of IPF in many countries, but is not recommended as a first-choice therapy by current guidelines because of the lack of a definite efficacy. Randomized controlled trials represent a valid choice for patients with IPF, and their completion is important in improving both survival and quality of life.

Pirfenidone in idiopathic pulmonary fibrosis: the CAPACITY program

Idiopathic pulmonary fibrosis is the most lethal form of diffuse lung fibrosis, killing approximately half of those affected within 2-3 years of diagnosis. Until recently, no therapies had been shown to have an impact on disease progression. The Clinical Studies Assessing Pirfenidone (Esbriet(®)) in IPF: Research of Efficacy and Safety Outcomes (CAPACITY) program comprised two almost identical double-blind placebo-controlled studies assessing the effects of pirfenidone on change in forced vital capacity, the primary end point, over a 72-week period. One of these studies was positive, matching in magnitude the benefit seen in two previous positive Japanese studies. The other study did not meet its primary end point but positive trends were consistent in this and a number of secondary end point indices. Safety was acceptable, comprising mainly problems of tolerability rather than toxicity. It is likely that pirfenidone will be utilised in many countries as first-line therapy and will also be included in studies of combination therapy for this attritional disease.