Systematic review: the relationship between interstitial lung diseases and gastro-oesophageal reflux disease

BACKGROUND A potential relationship has been suggested between gastro-oesophageal reflux disease (GERD) and interstitial lung diseases (ILDs). AIM To evaluate whether there is a causal relationship between GERD and different ILDs. METHODS We conducted a systematic search of literature published between 1980 and 2010. After a review by two independent authors, each study was assigned an evidence-based rating according to a standard scoring system. RESULTS We identified 319 publications and 22 of them met the entry criteria. Of those, the relationship between GERD and idiopathic pulmonary fibrosis (IPF) was investigated in 14 articles, pulmonary involvement in systemic sclerosis (SSc) in six articles and pulmonary involvement in mixed connective tissue disease (MCTD) in two articles. We found the prevalence of GERD and/or oesophageal dysmotility to be higher in patients with different types of ILD as compared with those without ILD [Evidence B]. Among patients with IPF, 67-76% demonstrated abnormal oesophageal acid exposure off PPI treatment. No relationship was demonstrated between severity of GERD and severity of IPF [Evidence B]. Data are scant on outcomes of antireflux treatment in patients with IPF. There is a correlation between the severity of ILD and the degree of oesophageal motor impairment in patients with SSc and MCTD [Evidence B]. CONCLUSIONS Based on the currently available data, a causal relationship between GERD and idiopathic pulmonary fibrosis cannot be established. There is scant evidence about antireflux therapy in idiopathic pulmonary fibrosis patients. There may be an association between lung and oesophageal involvement in systemic sclerosis and mixed connective tissue disease, but a causal relationship cannot be established.     

肺癌术后肺纤维化急性加重的诊疗进展

特发性肺纤维化（IPF）是一种特殊类型的间质性肺炎,以缓慢进展为特点,其病变局限在肺部,老年人多见,一部分病例会出现急性加重的过程,表现为原有肺部病变突然恶化和致死性的呼吸衰竭,并出现新的肺部阴影和弥漫性肺泡病理改变。特发性肺纤维化急性加重（AEIPF）可发生于接受肺切除术后的原发性肺癌患者,起病通常呈急性或亚急性过程,病因尚不明确,通常认为与不明原因的肺损伤相关,起病隐匿,病情进展迅速,病死率高,而且在临床缺乏常规的预防和治疗措施,成为困扰临床医生的难题。本文就肺癌术后特发性肺纤维化急性加重的病因、发生的危险因素、预测指标、预防、治疗、预后等方面做一系统综述。     

Recent advances in particulate-induced pulmonary fibrosis; for the application of possible strategy experimentally and clinically

Chronic interstitial lung diseases including pneumoconiosis have pathological characteristics which alter the lung structure and function consequent to the accumulation and activation of inflammatory cells in the lower respiratory tract. These activated cells usually secrete the inflammatory and fibrogenic mediators. Of the diffuse parenchymal lung diseases, the majority have no known etiology and idiopathic pulmonary fibrosis (IPF) is the diagnosis most frequently encountered by clinicians. Pathogenic similarities between pneumoconiosis and IPF provide a strong basis for hypothesizing that environmental agents may cause IPF. Many case-control studies have been published that provide further evidence for a number of associations between occupational and environmental exposures and IPF. Such reports support a strong evidence that IPF may be a heterogenous disorder associated with a number of environmental exposures. As a model of lung fibrosis, experimental pneumoconiosis is giving us a great information because crystalline silica is probably one of the most typical agent producing pulmonary fibrosis and the severity of its health effects and the widespread nature of exposure have been long recognized. Many papers provide evidence that particles have the potential to cause stimulation of phagocytes to release oxidants and such oxidative stress is believed to be a major factor in pulmonary inflammation followed by fibrotic change. Many kinds of cellular mediators are recognized as a implicating factor in this process including cell-to-cell interaction, enzymes, cytokines, arachidonic acid derivatives et al. Treatment of pneumoconiosis is an attractive and interesting topic. But, the mechanism of pathogenesis of pneumoconiosis is not thoroughly understood yet. Also, whether the process of fibrosis formation be retarded or not is questionable with some therapeutic trial. Therefore, a sensitive biomarker which is possible to estimate the pathological pathway in pneumoconiosis is needed. Our laboratory has studied particulate-induced pulmonary reaction for two decades consistently. This review will focus on signal transduction pathway involved in oxidative stress and some inhibitory agents with pleiotropic mechanism in pulmonary fibrosis. I will also introduce some data of animal studies with multidrug regimen as well.     

New Insights into the Pathogenesis and Treatment of Idiopathic Pulmonary Fibrosis: A Potential Role for Stem Cells in the Lung Parenchyma and Implications for Therapy

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and often fatal form of interstitial lung disease. It is characterized by injury with loss of lung epithelial cells and abnormal tissue repair, resulting in replacement of normal functional tissue, abnormal accumulation of fibroblasts and myofibroblasts, deposition of extracellular matrix, and distortion of lung architecture which results in respiratory failure. Despite improvements in the diagnostic approach to IPF and active research in recent years, the molecular mechanisms of the disease remain poorly understood. This highly lethal lung disorder continues to pose major clinical challenges since an effective therapeutic regimen has yet to be identified and developed. For example, a treatment modality has been based on the assumption that IPF is a chronic inflammatory disease, yet most available anti-inflammatory drugs are not effective in treating it. Hence researchers are now focusing on understanding alternative underlying mechanisms involved in the pathogenesis of IPF in the hope of discovering potentially new pharmaceutical targets. This paper will focus on lung tissue repair, regeneration, remodeling, and cell types that may be important to consider in therapeutic interventions and includes a more detailed discussion of the potential targets of current therapeutic attack in pulmonary fibrosis. The discovery that adult bone marrow stem cells can contribute to the formation of differentiated cell types in other tissues, especially after injury, implies that they have the potential to participate in tissue remodeling, and perhaps regeneration. The current promise of the use of adult stem cells for tissue regeneration, and the belief that once irreversibly damaged tissue could be restored to a normal functional capacity using stem cell-based therapy, suggests a novel approach for treatment of diverse chronic diseases. However this optimism is tempered by current evidence that the pathogenesis of pulmonary fibrosis may involve the recruitment of bone marrow-derived fibroblasts, which are the key contributors to the pathogenesis of this chronic progressive disorder. Nevertheless, stem cell-related therapies are widely viewed as promising treatment options for patients suffering from various types of pulmonary diseases. Gender mismatched bone marrow or lung transplant recipients serve as natural populations in which to study the role of bone marrow-derived stem cells in recovery from pulmonary diseases. Understanding the mechanism of recruitment of stem cells to sites of injury, and their involvement in tissue repair, regeneration, and remodeling may offer a novel therapeutic target for developing more effective treatments against this fatal disorder. This article reviews the new concepts in the pathogenesis, current and future treatment options of pulmonary fibrosis, and the recent advances regarding the roles of stem cells in lung tissue repair, regeneration, and remodeling.     

Emerging drugs for idiopathic pulmonary fibrosis

Pulmonary fibrosis is often the end stage of chronic, persistent, low-level lung injury, either of known or unknown cause. The most severe form of pulmonary fibrosis is idiopathic pulmonary fibrosis (IPF), a disease process of unknown aetiology and one that often leads to respiratory failure and death. At present there are no proven or effective drug therapies for IPF. Recent advances in understanding of disease pathogenesis have focused attention on drug targeting of fibrogenic pathways, as opposed to traditional anti-inflammatory approaches. In this report, the present status of drug development of a number of emerging antifibrotic strategies and agents that may prove more effective in the therapy of this progressive, debilitating and fatal disease are reviewed.     

Emerging drugs for idiopathic pulmonary fibrosis

Pulmonary fibrosis is often the end stage of chronic, persistent, low-level lung injury, either of known or unknown cause. The most severe form of pulmonary fibrosis is idiopathic pulmonary fibrosis (IPF), a disease process of unknown aetiology and one that often leads to respiratory failure and death. At present there are no proven or effective drug therapies for IPF. Recent advances in understanding of disease pathogenesis have focused attention on drug targeting of fibrogenic pathways, as opposed to traditional anti-inflammatory approaches. In this report, the present status of drug development of a number of emerging antifibrotic strategies and agents that may prove more effective in the therapy of this progressive, debilitating and fatal disease are reviewed.     

CXCL12/CXCR4生物轴与特发性肺纤维化研究进展

特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是一种病因未明的肺间质性疾病,以肺泡上皮损伤、纤维细胞增殖、肌成纤维细胞形成、细胞外基质沉积为主要病理特征。CXCR4是纤维细胞主要的趋化因子受体,CXCL12是CXCR4的唯一配体。大量研究表明,在缺氧、HIF-1α、PI3K-Akt-mTOR路径的调节下,CXCL12/CXCR4生物轴(CXCL12/CX-CR4biological axis)能促进纤维细胞增殖、肌成纤维细胞形成、细胞外基质沉积,加速肺纤维化发病进程。该文将就CXCL12/CXCR4生物轴在特发性肺纤维化发病过程中的作用进行综述。     

Bosentan for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a debilitating, fatal, chronic fibrosing lung disease with no known effective therapy. Endothelin-1 may underlie the pathogenesis of lung fibrosis, therefore it was hypothesized that the oral dual endothelin receptor antagonist bosentan may have efficacy for the treatment of IPF. The BUILD-1 study evaluated the efficacy, safety and tolerability of bosentan in patients with IPF. Bosentan was associated with a trend toward delayed time to disease progression or death and improvement in quality-of-life, both of which were more pronounced in patients with a biopsy-confirmed IPF diagnosis. These observations are being investigated in the ongoing BUILD-3 trial.     

S1PR1 serves as a viable drug target against pulmonary fibrosis by increasing the integrity of the endothelial barrier of the lung

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with unclear etiology and limited treatment options. The median survival time for IPF patients is approximately 2–3 years and there is no effective intervention to treat IPF other than lung transplantation. As important components of lung tissue, endothelial cells (ECs) are associated with pulmonary diseases. However, the role of endothelial dysfunction in pulmonary fibrosis (PF) is incompletely understood. Sphingosine-1-phosphate receptor 1 (S1PR1) is a G protein-coupled receptor highly expressed in lung ECs. Its expression is markedly reduced in patients with IPF. Herein, we generated an endothelial-conditional S1pr1 knockout mouse model which exhibited inflammation and fibrosis with or without bleomycin (BLM) challenge. Selective activation of S1PR1 with an S1PR1 agonist, IMMH002, exerted a potent therapeutic effect in mice with bleomycin-induced fibrosis by protecting the integrity of the endothelial barrier. These results suggest that S1PR1 might be a promising drug target for IPF therapy.     

Interstitial lung disease in systemic sclerosis: pathophysiology, current and new advances in therapy

Systemic sclerosis is an autoimmune connective tissue disorder characterized by fibrosis of the skin and visceral organs. Interstitial lung disease (ILD) is a major complication of this disease and along with pulmonary arterial hypertension is the leading cause of mortality in scleroderma patients. The pathogenesis of pulmonary fibrosis is characterized by epithelial cell injury, activation of the coagulation pathway and inflammation, which create a profibrogenic environment in the lung in the setting of autoimmunity. The current standard of treatment for ILD in systemic sclerosis is cyclophosphamide. In view of the modest benefits in pulmonary function seen with cyclophosphamide in two recent trials and its significant toxicity, the search for alternative treatments is ongoing. With the advances in our understanding of the pathogenic mechanisms of pulmonary fibrosis, many promising therapeutic agents have come into view, but their efficacy needs to be evaluated before they can be recommended clinically. This review discusses the pathogenesis of pulmonary fibrosis with a focus on the potential target pathways, the current treatment options and recent advances in the treatment of ILD in systemic sclerosis.     

特发性肺纤维化的组学研究进展

特发性肺纤维化(IPF)是一种原因不明的以呼吸困难和肺功能进行性恶化为特征的慢性肺纤维化性疾病,预后不良。IPF的病因尚未完全阐明,与老化、遗传、环境暴露、氧化应激和微生物-宿主防御反应有关。基因突变、转录和翻译异常、表观基因调控改变及代谢紊乱均可能影响疾病的发生和发展。近年来,采用高通量技术的组学研究从多维度揭示了IPF的发病机制,为寻找生物标志物和治疗靶点提供了新视角。本文综述了应用基因组学、转录组学、表观基因组学、蛋白质组学和代谢组学技术阐明IPF发病机制、寻找生物标志物、提供治疗靶点的最新研究进展。     

氧化应激在特发性肺纤维化中的作用及其机制研究进展

特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是以弥漫性肺泡炎和成纤维细胞病理性增生最终导致肺间质纤维化为病理特征的慢性进展性疾病。IPF发病机制尚未完全明确。成肌纤维细胞(myofibroblast)增多是目前学术界认为最为重要的IPF发生致病的主要机制。同时氧化/抗氧化失衡引起的氧化应激反应是其发病重要机制之一。纠正体内氧化/抗氧化失衡能减轻肺纤维化的程度,因此有望成为治疗特发性肺纤维化的一种新方法。该文就近年来氧化应激反应在IPF中的作用及其机制研究进展作一综述。     

Idiopathic pulmonary fibrosis: pathogenesis and therapeutic approaches

Idiopathic pulmonary fibrosis (IPF), also termed cryptogenic fibrosing alveolitis, is a clinicopathological syndrome characterised by cough, exertional dyspneoa, basilar crackles, a restrictive defect on pulmonary function tests, honeycombing on high-resolution, thin-section computed tomographic scans and the histological diagnosis of usual interstitial pneumonia on lung biopsy. The course is usually indolent but inexorable. Most patients die of progressive respiratory failure within 3-8 years of the onset of symptoms. Current therapies are of unproven benefit. Although the pathogenesis of IPF has not been elucidated, early concepts focused on lung injury leading to a cycle of chronic alveolar inflammation eventuating in fibrosis and destruction of the lung architecture. Anti-inflammatory therapies employing corticosteroids or immunosuppressive or cytotoxic agents have been disappointing. More recent hypotheses acknowledge that sequential alveolar epithelial cell injury is likely to be a key event in the pathogenesis of IPF, but the cardinal event is an aberrant host response to wound healing. In this context, abnormal epithelial-mesenchymal interactions, altered fibroblast phenotypes, exaggerated fibroblast proliferation, and excessive deposition of collagen and extracellular matrix are pivotal to the fibrotic process. Several clinical trials are currently underway or in the planning stages, and include drugs such as interferon-gamma 1b, pirfenidone, acetylcysteine, etanercept (a tumor necrosis factor-alpha antagonist), bosentan (an endothelin-1 receptor antagonist) and zileuton (a 5-lypoxygenase inhibitor). Future therapeutic strategies should be focused on alveolar epithelial cells aimed at enhancing re-epithelialisation and on fibroblastic/myofibroblastic foci, which play an essential role in the development of IPF. Stem cell progenitors of the alveolar epithelial cells and genetic and epigenetic therapies are attractive future approaches for this and other fibrotic lung disorders.     

Surfactant protein A--from genes to human lung diseases

Surfactant associated protein-A (SP-A) is the most abundant pulmonary surfactant protein and belongs to the family of innate host defense proteins termed collectins. Besides pulmonary host defense, SP-A is also involved in the formation of pulmonary surfactant, as it is essential for the structure of tubular myelin. The human SP-A gene locus includes two functional genes, SFTPA1 and SFTPA2 which are expressed independently, and a pseudo gene. The largest amount of SP-A1 proteins assemble to larger molecular complexes, whereas SP-A2 forms mainly dimers and trimers. SP-A polymorphisms play a role in respiratory distress syndrome, allergic bronchopulmonary aspergillosis and idiopathic pulmonary fibrosis. The levels of SP-A are decreased in the lungs of patients with cystic fibrosis, respiratory distress syndrome and further chronic lung diseases. Future areas for clinical research include disease specific SP-A expression pattern and their functional consequences, the differential roles of SP-A1 and SP-A2 in human lung diseases, and therapeutical approaches to correct altered SP-A levels.     

自噬调节与特发性肺纤维化药物治疗研究进展

特发性肺纤维化（idiopathic pulmonary fibrosis，IPF）是一种病因复杂、与年龄相关的肺纤维化疾病，其发病过程表现出进行性与不可逆性，最终导致患者呼吸系统衰竭而死亡。近些年的研究证实自噬参与了IPF的发生发展。本文回顾总结了自噬和IPF相关的临床研究、动物和细胞模型研究以及基于自噬的药物治疗研究，希望对阐明IPF的病理机制和药物研发有所帮助。     

厄洛替尼致间质性肺疾病的特点、机制及防治简

厄洛替尼为表皮生长因子受体酪氨酸激酶抑制剂（EGFR—TKI）,临床用于治疗非小细胞肺癌。问质性肺疾病（ILD）是厄洛替尼严重而少见的不良反应,发生率为0．1％～4．8％,病死率为0．8％～2．4％。厄洛替尼引起ILD的中位时间为用药22d,临床表现为干咳、低热、呼吸困难等,影像学检查可见双肺弥漫性磨玻璃样阴影,实验室检查显示低氧血症。男性、高龄、有基础肺部病变及吸烟等为危险因素。厄洛替尼致ILD的主要机制为免疫介导和药物的直接毒性。避免对高危患者用药、使用低剂量、避免与其他化疗药物和／或放射治疗同步应用、加强呼吸功能监测是预防厄洛替尼致ILD的有效措施。一旦发生ILD应立即停用厄洛替尼,换用其他EGFR—TKI。厄洛替尼致ILD的治疗以抑制炎症反应及防止肺纤维化为主要目的,主要措施包括吸氧、应用糖皮质激素,预防感染和对症治疗。     

Emerging drugs for idiopathic pulmonary fibrosis

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and usually lethal lung disorder of unknown etiology. The disease is characterized by alveolar epithelial cell injury, formation of activated fibroblasts/myofibroblasts foci and finally by the exaggerated accumulation of extracellular matrix with the subsequent destruction of the lung architecture. The long-term survival is distinctly poor, with only a 20-30% survival 5 years after the time of diagnosis. Actually, regardless of extensive research, no current therapy has been shown to either reverse or stop the progression of this disease. AREAS COVERED: The authors searched the Medline database from January 1990 to December 2010 using search terms 'pulmonary fibrosis', 'fibrosing alveolitis' and 'usual interstitial pneumonia'. Several subsets were included: definition and epidemiology, risk factors, clinical behavior, pathogenesis and therapy. For the section of IPF treatment, the authors examined all relevant studies including randomized controlled trials, cohort studies, case-control studies and cross-sectional studies. In this review, the authors describe the current therapeutic approaches, the ongoing clinical trials and some future options based on stem cells, lung bioengineering and microRNAs. EXPERT OPINION: The treatment of IPF represents one of the greatest challenges confronting respiratory medicine and, currently, there is no effective therapeutic option for IPF. Perhaps some of the drugs that are under evaluation in clinical trials will slow the decline of the pulmonary function tests or hopefully stabilize some patients. Nonetheless, it appears clear that new therapeutic approaches are urgently needed.     

Precision medicine in idiopathic pulmonary fibrosis therapy: From translational research to patient-centered care

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible fibrotic chronic lung disease affecting predominantly older adults, with a history of smoking. The current model of disease natural course is that recurrent injury of the alveolar epithelium in the context of advanced aging/cellular senescence is followed by defective re-epithelialization and scar tissue formation. Currently, two drugs, nintedanib and pirfenidone, that modify disease progression have been approved worldwide for the treatment of IPF. However, despite treatment, patients with IPF are not cured, and eventually, disease advances in most treated patients. Enhancing biogenomic and metabolic research output, its translation into clinical precision and optimal service delivery through patient-centeredness are key elements to support effective IPF care. In this review, we summarize therapeutic options currently investigated for IPF based on the major pathogenetic pathways and molecular targets that drive pulmonary fibrosis.     

Interferon-gamma 1b: impact of new indications (idiopathic pulmonary fibrosis)

Idiopathic pulmonary fibrosis (IPF) is a relentlessly progressive disease with inadequate response to conventional treatment with corticosteroids and/or immunosuppressive agents in most patients. Interferon-gamma (IFN-gamma), an antifibrotic agent, has been proposed as a novel therapeutic approach. Several investigators have shown a relative decrease in systemic and pulmonary IFN-gamma activity in patients with IPF. Experimental evidence from animal and human studies also suggests that IFN-gamma administration may ameliorate lung fibrosis. Clinical experience is, however, limited to a single clinical trial that showed objective functional improvement in a small number of patients treated with IFN-gamma and low-dose corticosteroids. Further research is needed to characterise the efficacy, safety and optimum route of administration of this agent before it can be recommended for use in routine clinical practice.     

Interferon-γ 1b: impact of new indications (idiopathic pulmonary fibrosis)

Idiopathic pulmonary fibrosis (IPF) is a relentlessly progressive disease with inadequate response to conventional treatment with corticosteroids and/or immunosuppressive agents in most patients. Interferon-γ (IFN-γ), an antifibrotic agent, has been proposed as a novel therapeutic approach. Several investigators have shown a relative decrease in systemic and pulmonary IFN-γ activity in patients with IPF. Experimental evidence from animal and human studies also suggests that IFN-γ administration may ameliorate lung fibrosis. Clinical experience is, however, limited to a single clinical trial that showed objective functional improvement in a small number of patients treated with IFN-γ and low-dose corticosteroids. Further research is needed to characterise the efficacy, safety and optimum route of administration of this agent before it can be recommended for use in routine clinical practice.