Pharmacological management of progressive-fibrosing interstitial lung diseases: a review of the current evidence

Advances in management of pulmonary fibrosis

Pulmonary fibrosis care, affecting both idiopathic pulmonary fibrosis and other forms of interstitial lung disease (ILD) characterised by fibrosis, has transformed with a range of innovations that affect the diagnosis, treatment and prognosis of this condition. Pharmacotherapeutic options have expanded, with increased indications for the application of effective antifibrotic therapy in non-IPF progressive pulmonary fibrosis as a solo treatment or combined with immunosuppression, emerging evidence for immunomodulatory therapy including biologic agents and greater access to clinical trials. The diagnostic approach to unclassifiable ILD now includes transbronchial lung cryobiopsy, a less invasive method to obtain histopathology with reduced morbidity and mortality compared to surgical lung biopsy. A multidisciplinary approach optimises the care of people with ILD and includes non-pharmacological management, addressing significant comorbidities, symptom care and advanced care planning. This review will summarise recent updates in pulmonary fibrosis management.

Pirfenidone in post-COVID-19 pulmonary fibrosis (FIBRO-COVID): a phase 2 randomised clinical trial

BACKGROUND

Patients with severe COVID-19 may develop lung fibrosis. Pirfenidone is an anti-fibrotic drug approved for idiopathic pulmonary fibrosis. The efficacy and safety of pirfenidone in patients with fibrotic interstitial lung changes after recovery from severe COVID-19 pneumonia were evaluated.

METHODS

This was a phase 2, double-blind, placebo-controlled, Spanish multicentre clinical trial. Patients were randomised to receive pirfenidone or placebo (2:1) for 24 weeks. The primary end-point was the proportion of patients that improved, considered when percentage change in forced vital capacity (FVC) was ≥10% and/or any reduction in the fibrotic score on chest high-resolution computed tomography (HRCT). Secondary end-points included health-related quality of life (HRQoL), exercise capacity and drug safety profile.

RESULTS

From 119 eligible patients, 113 were randomised and 103 were analysed (pirfenidone n=69 and placebo n=34). Most patients were male (73.5%) and were receiving low-dose prednisone; mean age was 63.7 years and mean body mass index was 29 kg·m-2. The percentage of patients that improved was similar in the pirfenidone and placebo groups (79.7% versus 82.3%, respectively). The mean predicted FVC increased by 12.74±20.6% with pirfenidone and 4.35±22.3% with placebo (p=0.071), and the HRCT (%) fibrotic score decreased by 5.44±3.69% with pirfenidone and 2.57±2.59% with placebo (p=0.52). Clinically meaningful improvement in HRQoL was not statistically different (55.2% in the pirfenidone group and 39.4% in the placebo group). Exercise capacity, adverse events and hospitalisations were similar between groups. No deaths were reported.

CONCLUSIONS

The overall improvements in lung function and HRCT fibrotic score after 6 months with pirfenidone were not significantly different than with placebo.

Interstitial lung disease in rheumatic diseases: an update of the 2018 review

INTRODUCTION

Interstitial lung disease (ILD) is a potential severe complication of various rheumatic diseases, typically connective tissue diseases (CTD), associated with significant morbidity and mortality. ILD may occur during the course of the disease but may also be its first manifestation. Several cell types are involved in ILD's pathogenesis, and if not controlled, pulmonary inflammation may lead to pulmonary fibrosis.

AREAS COVERED

We searched PubMed, Medline, and the Cochrane Library for papers published between 1995 and February 2017 in the first version, and between 2017 and April 2023 using combinations of words. The most frequent systemic rheumatic diseases associated with ILD are systemic sclerosis (SSc), rheumatoid arthritis (RA), and idiopathic inflammatory myositis. Treatment and monitoring guidelines are still lacking, and current treatment strategies have been extrapolated from the literature on SSc and established treatments for non-pulmonary systemic rheumatic manifestations.

EXPERT OPINION

Given the complexity of diagnosis and the paucity of treatment trials, managing CTD patients with ILD is challenging. It requires the skills of multidisciplinary CTD-ILD clinics including at least rheumatologists and lung specialists.

Cyclic nucleotide phosphodiesterases as drug targets

Cyclic nucleotides are synthesized by adenylyl and/or guanylyl cyclase, and downstream of this synthesis, the cyclic nucleotide phosphodiesterase families (PDEs) specifically hydrolyze cyclic nucleotides. PDEs control cyclic adenosine-3',5'monophosphate (cAMP) and cyclic guanosine-3',5'-monophosphate (cGMP) intracellular levels by mediating their quick return to the basal steady state levels. This often takes place in subcellular nanodomains. Thus, PDEs govern short-term protein phosphorylation, long-term protein expression, and even epigenetic mechanisms by modulating cyclic nucleotide levels. Consequently, their involvement in both health and disease is extensively investigated. PDE inhibition has emerged as a promising clinical intervention method, with ongoing developments aiming to enhance its efficacy and applicability. In this comprehensive review, we extensively look into the intricate landscape of PDEs biochemistry, exploring their diverse roles in various tissues. Furthermore, we outline the underlying mechanisms of PDEs in different pathophysiological conditions. Additionally, we review the application of PDE inhibition in related diseases, shedding light on current advancements and future prospects for clinical intervention. SIGNIFICANCE STATEMENT: Regulating PDEs is a critical checkpoint for numerous (patho)physiological conditions. However, despite the development of several PDE inhibitors aimed at controlling overactivated PDEs, their applicability in clinical settings poses challenges. In this context, our focus is on pharmacodynamics and the structure activity of PDEs, aiming to illustrate how selectivity and efficacy can be optimized. Additionally, this review points to current preclinical and clinical evidence that depicts various optimization efforts and indications.

Percent Predicted vs. Absolute Six-Minute Walk Distance as Predictors of Lung Transplant-Free Survival in Fibrosing Interstitial Lung Diseases

INTRODUCTION

Fibrosing interstitial lung diseases (ILDs) often progress despite treatment and become life-threatening, with lung transplant (LTx) remaining the only curative option. Six-minute walk distance (6MWD) is increasingly recognized as reliable predictor of clinical course, especially when longitudinally considered. The use of reference equations to express 6MWD as percent predicted (6MWD%) has not been previously studied in fibrosing ILDs. We sought to investigate whether the prognostic power of 6MWD% is superior to that of 6MWD expressed in meters (6MWD-m).

METHODS

A retrospective, multicenter cohort analysis was conducted on both idiopathic pulmonary (IPF) and non-IPF fibrosing ILD patients. Patients were divided into a discovery (n = 211) and a validation (n = 260) cohort. Longitudinal changes of 6MWD% and lung function parameters were simultaneously considered. LTx-free survival at 3 years from baseline was the endpoint. Competing risks of death and LTx were considered.

RESULTS

Baseline 6MWD% and its longitudinal changes were significant predictors of LTx-free survival and independent from lung function variables. In both cohorts, on multivariate cox proportional hazard regression analysis, receiver operating characteristics analysis and Kaplan-Meier estimates, 6MWD% was consistently, but only slightly superior to 6MWD-m as a predictor of LTx-free survival.

CONCLUSION

6MWD% has only a slight, yet detectable advantage over 6MWD-m as a predictor of survival in fibrosing ILDs. Utilizing 6MWD% may aid in risk stratification, treatment monitoring, and LTx timing optimization. However, available reference equations do have predicting limitations. Refined predictive equations and standardizing reporting practices are therefore needed to further enhance the clinical utility of 6MWD% in fibrosing ILDs.

Comprehensive analysis of scRNA-Seq and bulk RNA-Seq reveals ubiquitin promotes pulmonary fibrosis in chronic pulmonary diseases

It is estimated that there are 544.9 million people suffering from chronic respiratory diseases in the world, which is the third largest chronic disease. Although there are various clinical treatment methods, there is no specific drug for chronic pulmonary diseases, including chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD) and idiopathic pulmonary fibrosis (IPF). Therefore, it is urgent to clarify the pathological mechanism and medication development. Single-cell transcriptome data of human and mouse from GEO database were integrated by "Harmony" algorithm. The data was standardized and normalized by using "Seurat" package, and "SingleR" algorithm was used for cell grouping annotation. The "Findmarker" function is used to find differentially expressed genes (DEGs), which were enriched and analyzed by using "clusterProfiler", and a protein interaction network was constructed for DEGs, and four algorithms are used to find the hub genes. The expression of hub genes were analyzed in independent human and mouse single-cell transcriptome data. Bulk RNA data were used to integrate by the "SVA" function, verify the expression levels of hub genes and build a diagnostic model. The L1000FWD platform was used to screen potential drugs. Through exploring the similarities and differences by integrated single-cell atlas, we found that the lung parenchymal cells showed abnormal oxidative stress, cell matrix adhesion and ubiquitination in COPD, corona virus disease 2019 (COVID-19), ILD and IPF. Meanwhile, the lung resident immune cells showed abnormal Toll-like receptor signals, interferon signals and ubiquitination. However, unlike acute pneumonia (COVID-19), chronic pulmonary disease shows enhanced ubiquitination. This phenomenon was confirmed in independent external human single-cell atlas, but unfortunately, it was not confirmed in mouse single-cell atlas of bleomycin-induced pulmonary fibrosis model and influenza virus-infected mouse model, which means that the model needs to be optimized. In addition, the bulk RNA-Seq data of COVID-19, ILD and IPF was integrated, and we found that the immune infiltration of lung tissue was enhanced, consistent with the single-cell level, UBA52, UBB and UBC were low expressed in COVID-19 and high expressed in ILD, and had a strong correlation with the expression of cell matrix adhesion genes. UBA52 and UBB have good diagnostic efficacy, and salermide and SSR-69071 can be used as their candidate drugs. Our study found that the disorder of protein ubiquitination in chronic pulmonary diseases is an important cause of pathological phenotype of pulmonary fibrosis by integrating scRNA-Seq and bulk RNA-Seq, which provides a new horizons for clinicopathology, diagnosis and treatment.

Ultrasonic surface acoustic wave elastography: A review of basic theories, technical developments, and medical applications

Physiological and pathological changes in tissues often cause changes in tissue mechanical properties, making tissue elastography an effective modality in medical imaging. Among the existing elastography methods, ultrasound elastography is of great interest due to the inherent advantages of ultrasound imaging technology, such as low cost, portability, safety, and wide availability. However, most current ultrasound elastography methods are based on the bulk shear wave; they can image deep tissues but cannot image superficial tissues. To address this challenge, ultrasonic elastography methods based on surface acoustic waves have been proposed. In this paper, we present a comprehensive review of ultrasound-based surface acoustic wave elastography techniques, including their theoretical foundations, technical implementations, and existing medical applications. The goal is to provide a concise summary of the state-of-the-art of this field, hoping to offer a reliable reference for the further development of these techniques and foster the expansion of their medical applications.

Interstitial lung disease: a review of classification, etiology, epidemiology, clinical diagnosis, pharmacological and non-pharmacological treatment

Interstitial lung diseases (ILDs) refer to a heterogeneous and complex group of conditions characterized by inflammation, fibrosis, or both, in the interstitium of the lungs. This results in impaired gas exchange, leading to a worsening of respiratory symptoms and a decline in lung function. While the etiology of some ILDs is unclear, most cases can be traced back to factors such as genetic predispositions, environmental exposures (including allergens, toxins, and air pollution), underlying autoimmune diseases, or the use of certain medications. There has been an increase in research and evidence aimed at identifying etiology, understanding epidemiology, improving clinical diagnosis, and developing both pharmacological and non-pharmacological treatments. This review provides a comprehensive overview of the current state of knowledge in the field of interstitial lung diseases.

Treatment of idiopathic pulmonary fibrosis and progressive pulmonary fibrosis: A position statement from the Thoracic Society of Australia and New Zealand 2023 revision

Idiopathic pulmonary fibrosis (IPF) is a progressive disease leading to significant morbidity and mortality. In 2017 the Thoracic Society of Australia and New Zealand (TSANZ) and Lung Foundation Australia (LFA) published a position statement on the treatment of IPF. Since that time, subsidized anti-fibrotic therapy in the form of pirfenidone and nintedanib is now available in both Australia and New Zealand. More recently, evidence has been published in support of nintedanib for non-IPF progressive pulmonary fibrosis (PPF). Additionally, there have been numerous publications relating to the non-pharmacologic management of IPF and PPF. This 2023 update to the position statement for treatment of IPF summarizes developments since 2017 and reaffirms the importance of a multi-faceted approach to the management of IPF and progressive pulmonary fibrosis.

iPSCs as a groundbreaking tool for the study of adverse drug reactions: A new avenue for personalized therapy

Induced pluripotent stem cells (iPSCs), obtained by reprogramming different somatic cell types, represent a promising tool for the study of drug toxicities, especially in the context of personalized medicine. Indeed, these cells retain the same genetic heritage of the donor, allowing the development of personalized models. In addition, they represent a useful tool for the study of adverse drug reactions (ADRs) in special populations, such as pediatric patients, which are often poorly represented in clinical trials due to ethical issues. Particularly, iPSCs can be differentiated into any tissue of the human body, following several protocols which use different stimuli to induce specific differentiation processes. Differentiated cells also maintain the genetic heritage of the donor, and therefore are suitable for personalized pharmacological studies; moreover, iPSC-derived differentiated cells are a valuable tool for the investigation of the mechanisms underlying the physiological differentiation processes. iPSCs-derived organoids represent another important tool for the study of ADRs. Precisely, organoids are in vitro 3D models which better represent the native organ, both from a structural and a functional point of view. Moreover, in the same way as iPSC-derived 2D models, iPSC-derived organoids are appropriate personalized models since they retain the genetic heritage of the donor. In comparison to other in vitro models, iPSC-derived organoids present advantages in terms of versatility, patient-specificity, and ethical issues. This review aims to provide an updated report of the employment of iPSCs, and 2D and 3D models derived from these, for the study of ADRs. This article is categorized under: Cancer > Stem Cells and Development.

Mechanisms and management of cough in interstitial lung disease

INTRODUCTION

Many patients with interstitial lung diseases (ILDs), especially fibrotic ILDs, experience chronic cough. It negatively impacts both physical and psychological well-being. Effective treatment options are limited.

AREAS COVERED

The pathophysiology of chronic cough in IPF is complex and involves multiple mechanisms, including mechanical distortion of airways, parenchyma, and nerve fibers. The pathophysiology of cough in other fibrosing ILDs is poorly understood and involves various pathways. The purpose of this review is to highlight mechanisms of chronic cough and to present therapeutic evidence for its management in the most commonly occurring diffuse fibrosing lung diseases including idiopathic pulmonary fibrosis (IPF), connective tissue disease-related interstitial lung disease (CTD-ILD), sarcoidosis-related ILD (Sc-ILD), chronic hypersensitivity pneumonitis-related ILD (CHP-ILD), and post-COVID-19-related interstitial lung disease (PC-ILD).

EXPERT OPINION

This review guides the management of chronic cough in fibrosing ILDs. In this era of precision medicine, chronic cough management should be individualized in each interstitial lung disease.

Fibroblast Activation Protein Alpha (FAPα) in Fibrosis: Beyond a Perspective Marker for Activated Stromal Cells?

The development of tissue fibrosis is a complex process involving the interaction of multiple cell types, which makes the search for antifibrotic agents rather challenging. So far, myofibroblasts have been considered the key cell type that mediated the development of fibrosis and thus was the main target for therapy. However, current strategies aimed at inhibiting myofibroblast function or eliminating them fail to demonstrate sufficient effectiveness in clinical practice. Therefore, today, there is an unmet need to search for more reliable cellular targets to contribute to fibrosis resolution or the inhibition of its progression. Activated stromal cells, capable of active proliferation and invasive growth into healthy tissue, appear to be such a target population due to their more accessible localization in the tissue and their high susceptibility to various regulatory signals. This subpopulation is marked by fibroblast activation protein alpha (FAPα). For a long time, FAPα was considered exclusively a marker of cancer-associated fibroblasts. However, accumulating data are emerging on the diverse functions of FAPα, which suggests that this protein is not only a marker but also plays an important role in fibrosis development and progression. This review aims to summarize the current data on the expression, regulation, and function of FAPα regarding fibrosis development and identify promising advances in the area.

Design of a phase III, double-blind, randomised, placebo-controlled trial of BI 1015550 in patients with progressive pulmonary fibrosis (FIBRONEER-ILD)

INTRODUCTION

Progressive pulmonary fibrosis (PPF) includes any diagnosis of progressive fibrotic interstitial lung disease (ILD) other than idiopathic pulmonary fibrosis (IPF). However, disease progression appears comparable between PPF and IPF, suggesting a similar underlying pathology relating to pulmonary fibrosis. Following positive results in a phase II study in IPF, this phase III study will investigate the efficacy and safety of BI 1015550 in patients with PPF (FIBRONEER-ILD).

METHODS AND ANALYSIS

In this phase III, double-blind, placebo-controlled trial, patients are being randomised 1:1:1 to receive BI 1015550 (9 mg or 18 mg) or placebo twice daily over at least 52 weeks, stratified by background nintedanib use. Patients must be diagnosed with pulmonary fibrosis other than IPF that is progressive, based on predefined criteria. Patients must have forced vital capacity (FVC) ≥45% predicted and haemoglobin-corrected diffusing capacity of the lung for carbon monoxide ≥25% predicted. Patients must be receiving nintedanib for at least 12 weeks, or not receiving nintedanib for at least 8 weeks, prior to screening. Patients on stable treatment with permitted immunosuppressives (eg, methotrexate, azathioprine) may continue their treatment throughout the trial. Patients with clinically significant airway obstruction or other pulmonary abnormalities, and those using immunosuppressives that may confound FVC results (cyclophosphamide, tocilizumab, mycophenolate, rituximab) or high-dose steroids will be excluded. The primary endpoint is absolute change from baseline in FVC (mL) at week 52. The key secondary endpoint is time to the first occurrence of any acute ILD exacerbation, hospitalisation for respiratory cause or death, over the duration of the trial.

ETHICS AND DISSEMINATION

The trial is being carried out in accordance with the ethical principles of the Declaration of Helsinki, the International Council on Harmonisation Guideline for Good Clinical Practice and other local ethics committees. The study results will be disseminated at scientific congresses and in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05321082.

Pharmacological approaches to pulmonary fibrosis following COVID-19

Background: In the past few years, COVID-19 became the leading cause of morbidity and mortality worldwide. Although the World Health Organization has declared an end to COVID-19 as a public health emergency, it can be expected, that the emerging new cases at the top of previous ones will result in an increasing number of patients with post-COVID-19 sequelae. Despite the fact that the majority of patients recover, severe acute lung tissue injury can in susceptible individuals progress to interstitial pulmonary involvement. Our goal is to provide an overview of various aspects associated with the Post-COVID-19 pulmonary fibrosis with a focus on its potential pharmacological treatment options. Areas covered: We discuss epidemiology, underlying pathobiological mechanisms, and possible risk and predictive factors that were found to be associated with the development of fibrotic lung tissue remodelling. Several pharmacotherapeutic approaches are currently being applied and include anti-fibrotic drugs, prolonged use or pulses of systemic corticosteroids and non-steroidal anti-inflammatory and immunosuppressive drugs. In addition, several repurposed or novel compounds are being investigated. Fortunately, clinical trials focused on pharmacological treatment regimens for post-COVID-19 pulmonary fibrosis have been either designed, completed or are already in progress. However, the results are contrasting so far. High quality randomised clinical trials are urgently needed with respect to the heterogeneity of disease behaviour, patient characteristics and treatable traits. Conclusion: The Post-COVID-19 pulmonary fibrosis contributes to the burden of chronic respiratory consequences among survivors. Currently available pharmacotherapeutic approaches mostly comprise repurposed drugs with a proven efficacy and safety profile, namely, corticosteroids, immunosuppressants and antifibrotics. The role of nintedanib and pirfenidone is promising in this area. However, we still need to verify conditions under which the potential to prevent, slow or stop progression of lung damage will be fulfilled.

Towards a Unified Approach in Autoimmune Fibrotic Signalling Pathways

Autoimmunity is a chronic process resulting in inflammation, tissue damage, and subsequent tissue remodelling and organ fibrosis. In contrast to acute inflammatory reactions, pathogenic fibrosis typically results from the chronic inflammatory reactions characterizing autoimmune diseases. Despite having obvious aetiological and clinical outcome distinctions, most chronic autoimmune fibrotic disorders have in common a persistent and sustained production of growth factors, proteolytic enzymes, angiogenic factors, and fibrogenic cytokines, which together stimulate the deposition of connective tissue elements or epithelial to mesenchymal transformation (EMT) that progressively remodels and destroys normal tissue architecture leading to organ failure. Despite its enormous impact on human health, there are currently no approved treatments that directly target the molecular mechanisms of fibrosis. The primary goal of this review is to discuss the most recent identified mechanisms of chronic autoimmune diseases characterized by a fibrotic evolution with the aim to identify possible common and unique mechanisms of fibrogenesis that might be exploited in the development of effective antifibrotic therapies.

Efficacy and Safety of Nintedanib in Patients with Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD): A Real-World Single Center Experience

Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD) is a severe and fatal manifestation of systemic autoimmune disorders. Therapies rely on immunomodulators but their efficacy in ILD progression remains uncertain. Nintedanib, an antifibrotic agent that slows pulmonary function decline, has been approved for CTD-ILD treatment. The aim of this study was to assess the effectiveness and safety of nintedanib in CTD-ILD patients in a real-world data setting. A single-center, retrospective, and descriptive analysis of CTD-ILD patients treated with nintedanib from June 2019 to November 2022 was performed. The assessment of nintedanib treatment's efficacy was judged solely on the evolution of pulmonary function tests (PFTs), which were evaluated before and after treatment. Twenty-one patients (67% females, median age 64 years (IQR = 9) with CTD-ILD (systemic sclerosis n = 9, rheumatoid arthritis n = 5, dermatomyositis n = 4, juvenile rheumatoid arthritis n = 1, undifferentiated CTD n = 1, interstitial pneumonia with autoimmune features n = 1), 18 of whom were on concomitant immunosuppressives, had a median follow-up period of 10 months (IQR = 5). PFTs before and after treatment did not significantly differ. The mean FVC% difference was +0.9 (sd = 7.6) and the mean DLco% difference was +3.4 (sd = 12.6), suggesting numerical improvement of PFTs. The average percentage change was -0.3% and +7.6% for FVC% and DLco%, respectively, indicating stabilization of lung function. Our real-world data across a broad spectrum of CTD-ILD suggest that nintedanib could be beneficial in combination with immunosuppressives in slowing the rate of lung function decline.

Occupational hypersensitivity pneumonia

Hypersensitivity pneumonitis (HP) is an immunological lung disease that affects individuals who are sensitive and susceptible to occupational and environmental exposures. While clinical and radiological findings may resemble other interstitial lung diseases, identifying the causative agents can aid in the differential diagnosis. However, this can be challenging and may result in delayed diagnosis and poor prognosis. A gold standard test for diagnosis is currently unavailable, and therefore, a multidisciplinary approach involving a clinician, radiologist, and pathologist is necessary. Avoiding exposure is the first step in treatment, with immunosuppressive therapeutics also being used. Antifibrotic agents show promise for future treatment approaches. Despite recent advancements in data and guidelines, knowledge about managing occupational HP remains limited. This review provides a summary of the epidemiological, clinical, and radiological findings, as well as diagnostic and treatment principles of occupational HP based on current literature.

A monoclonal antibody targeting nonjunctional claudin-1 inhibits fibrosis in patient-derived models by modulating cell plasticity

Tissue fibrosis is a key driver of end-stage organ failure and cancer, overall accounting for up to 45% of deaths in developed countries. There is a large unmet medical need for antifibrotic therapies. Claudin-1 (CLDN1) is a member of the tight junction protein family. Although the role of CLDN1 incorporated in tight junctions is well established, the function of nonjunctional CLDN1 (njCLDN1) is largely unknown. Using highly specific monoclonal antibodies targeting a conformation-dependent epitope of exposed njCLDN1, we show in patient-derived liver three-dimensional fibrosis and human liver chimeric mouse models that CLDN1 is a mediator and target for liver fibrosis. Targeting CLDN1 reverted inflammation-induced hepatocyte profibrogenic signaling and cell fate and suppressed the myofibroblast differentiation of hepatic stellate cells. Safety studies of a fully humanized antibody in nonhuman primates did not reveal any serious adverse events even at high steady-state concentrations. Our results provide preclinical proof of concept for CLDN1-specific monoclonal antibodies for the treatment of advanced liver fibrosis and cancer prevention. Antifibrotic effects in lung and kidney fibrosis models further indicate a role of CLDN1 as a therapeutic target for tissue fibrosis across organs. In conclusion, our data pave the way for further therapeutic exploration of CLDN1-targeting therapies for fibrotic diseases in patients.

[Latest news on RA-ILD]

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is of high clinical relevance. It not only affects the quality of life but also makes a significant contribution to the mortality rate of patients with rheumatoid arthritis. RA-ILD can present with all known radiological and histopathological patterns seen in other interstitial pneumonias. Among these pneumonias, diffuse alveolar damage (DAD), followed by usual interstitial pneumonia (UIP) has the worst prognosis. In addition, acute exacerbation of RA-ILD, which can occur at any time during the disease, is highly lethal. An algorithm for the diagnosis and treatment of RA-ILD is pending and will be addressed in the following article. In addition to immunosuppressants and disease-modifying antirheumatic drugs (DMARD), antifibrotics have recently gained importance in the therapy of RA-ILD.

Discovery of a novel DDRs kinase inhibitor XBLJ-13 for the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic fatal lung disease characterized by destruction of lung parenchyma and deposition of extracellular matrix in interstitial and alveolar spaces. But known drugs for IPF are far from meeting clinical demands, validation of drug targets against pulmonary fibrosis is in urgent demand. Tyrosine kinase receptor DDRs has been considered as a potential therapeutic target for pulmonary fibrosis due to its pathological collagen binding property and the roles in regulating extracellular matrix remodeling. In this study we designed and synthesized a new indazole derivative XBLJ-13, and identified XBLJ-13 as a highly specific and potent DDRs inhibitor with anti-inflammation and anti-fibrosis activities. We first demonstrated that DDR1/2 was highly expressed in the lung tissues of IPF patients. Then we showed that XBLJ-13 potently inhibited DDR1 and DDR2 kinases with IC₅₀ values of 17.18 nM and 15.13 nM, respectively. Among a panel of 34 kinases tested, XBLJ-13 displayed relatively high selectivity for DDRs with minimal inhibitory effect on PDGFR family and FGFR1, as well as Abl kinase that had high homology with DDRs. Extensive profiling of XBLJ-13 revealed that the new inhibitor had much lower toxicity than nintedanib and better pharmacokinetic properties in mice. Furthermore, pharmacodynamic evaluation conducted in bleomycin-induced pulmonary fibrosis mice showed that administration of XBLJ-13 (30, 60, 90 mg·kg^-1·d^-1, i.g.) for 12 days significantly and dose-dependently ameliorated lung inflammation and fibrosis. Together, this study confirms that DDRs kinase is a potential target for PF, Particularly, compound XBLJ-13 is a highly potent and specific DDRs inhibitor, along with good pharmacokinetics profiles, and preferable in vivo efficacy, suggesting that it is a potential candidate for the treatment of PF.

BI 1015550 is a PDE4B Inhibitor and a Clinical Drug Candidate for the Oral Treatment of Idiopathic Pulmonary Fibrosis

The anti-inflammatory and immunomodulatory abilities of oral selective phosphodiesterase 4 (PDE4) inhibitors enabled the approval of roflumilast and apremilast for use in chronic obstructive pulmonary disease and psoriasis/psoriatic arthritis, respectively. However, the antifibrotic potential of PDE4 inhibitors has not yet been explored clinically. BI 1015550 is a novel PDE4 inhibitor showing a preferential enzymatic inhibition of PDE4B. In vitro, BI 1015550 inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) and phytohemagglutinin-induced interleukin-2 synthesis in human peripheral blood mononuclear cells, as well as LPS-induced TNF-α synthesis in human and rat whole blood. In vivo, oral BI 1015550 shows potent anti-inflammatory activity in mice by inhibiting LPS-induced TNF-α synthesis ex vivo and in Suncus murinus by inhibiting neutrophil influx into bronchoalveolar lavage fluid stimulated by nebulized LPS. In Suncus murinus, PDE4 inhibitors induce emesis, a well-known gastrointestinal side effect limiting the use of PDE4 inhibitors in humans, and the therapeutic ratio of BI 1015550 appeared to be substantially improved compared with roflumilast. Oral BI 1015550 was also tested in two well-known mouse models of lung fibrosis (induced by either bleomycin or silica) under therapeutic conditions, and appeared to be effective by modulating various model-specific parameters. To better understand the antifibrotic potential of BI 1015550 in vivo, its direct effect on human fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) was investigated in vitro. BI 1015550 inhibited transforming growth factor-β-stimulated myofibroblast transformation and the mRNA expression of various extracellular matrix proteins, as well as basic fibroblast growth factor plus interleukin-1β-induced cell proliferation. Nintedanib overall was unremarkable in these assays, but interestingly, the inhibition of proliferation was synergistic when it was combined with BI 1015550, leading to a roughly 10-fold shift of the concentration–response curve to the left. In summary, the unique preferential inhibition of PDE4B by BI 1015550 and its anticipated improved tolerability in humans, plus its anti-inflammatory and antifibrotic potential, suggest BI 1015550 to be a promising oral clinical candidate for the treatment of IPF and other fibro-proliferative diseases.

Nintedanib in Progressive Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

Background: To inform an American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax clinical practice guideline, this systematic review evaluated existing interstitial lung disease (ILD) literature to determine whether patients with progressive pulmonary fibrosis (PPF) should be treated with the antifibrotic nintedanib. Methods: A literature search was conducted across MEDLINE, EMBASE, and Cochrane databases through December 2020 for studies using nintedanib to treat patients with PPF. Mortality, disease progression, and adverse event data were extracted, and meta-analyses performed when possible. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group approach was used to assess the quality of evidence. Results: Two relevant studies were selected. The annual decline in FVC was less in the nintedanib arm in the overall study population [mean difference (MD) 107 milliliters (mL)/year (yr) (95% CI 65.4-148.5 mL/yr)] and in the subgroups with usual interstitial pneumonia (UIP) pattern of pulmonary fibrosis [MD 128.2 mL/yr (95% CI 70.8-185.6 mL/yr)], non-UIP patterns of pulmonary fibrosis [MD 75.3 mL/yr (95% CI 15.5-135.0 mL/yr)], fibrotic connective tissue disease-related ILD [MD 106.2 mL/yr (95% CI 10.6-201.9 mL/yr)], fibrotic idiopathic non-specific interstitial pneumonia [MD 141.7 mL/yr (95% CI 46.0-237.4 mL/yr)], and fibrotic occupational ILD [MD 252.8 mL/yr (95% CI 79.2-426.5 mL/yr)], but not fibrotic hypersensitivity pneumonitis [MD 72.9 mL/yr (95% CI -8.9-154.7 mL/yr)], fibrotic sarcoidosis [MD -20.5 mL/yr (95% CI -337.1-296.1 mL/yr)], or unclassified fibrotic ILD [MD 68.5 mL/yr (95% CI -31.3-168.4 mL/yr)] when compared to placebo. Gastrointestinal (GI) side effects were common. Quality of evidence for the outcomes ranged from very low to moderate GRADE. Conclusions: Nintedanib use in patients with PPF is associated with a statistically significant decrease in disease progression but increase in GI side effects regardless of the radiographic pattern of pulmonary fibrosis. However, limitations in the available evidence lead to low certainty in these effect estimates and make definitive conclusions about the differential effects by subtype of ILD difficult to determine.

Pirfenidone in Progressive Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

Background: To inform an American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax clinical practice guideline, this systematic review evaluated existing interstitial lung disease literature to determine whether patients with progressive pulmonary fibrosis (PPF) should be treated with the antifibrotic pirfenidone. Methods: A literature search was conducted across MEDLINE, EMBASE, and Cochrane databases through December 2020 for studies using pirfenidone to treat patients with PPF. Mortality, disease progression, lung function, and adverse event data were extracted, and meta-analyses performed when possible. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Working Group approach was used to assess the quality of evidence. Results: Two studies met inclusion criteria. Meta-analyses revealed changes in FVC % predicted [mean difference (MD) 2.3% (95% CI 0.5-4.1)], FVC in mL [MD 100.0 mL (95% CI 98.1-101.9)], and 6MWD in meters [MD 25.2 m (95% CI 8.3-42.1)] all favored pirfenidone to placebo. Change in DLCO in mmol/kPa/min [MD 0.40 mmol/kPa/min (95% CI 0.10-0.70)] and risk of DLCO declining more than 15% [relative risk (RR) 0.27 (95% CI 0.08-0.95)] also favored pirfenidone. The risks of gastrointestinal discomfort [RR 1.83 (95% CI 1.29-2.60)] and photosensitivity [RR 4.88 (95% CI 1.09-21.83)] were higher with pirfenidone. The quality of evidence was low or very low GRADE, depending on the outcome. Conclusions: Pirfenidone use in patients with PPF is associated with statistically significant decrease in disease progression and protection in lung function. However, there is very low certainty in the estimated effects due to limitations in the available evidence.

Care patterns of patients with chronic fibrosing interstitial lung disease (ILD) with a progressive phenotype

Background

Interstitial lung diseases (ILDs) include a variety of parenchymal lung diseases. The most common types of ILDs are idiopathic pulmonary fibrosis (IPF), autoimmune ILDs and hypersensitivity pneumonitis (HP). There is limited real world data on care patterns of patients with chronic fibrosing ILDs with a progressive phenotype other than IPF. Therefore, the aim of this study is to describe care patterns in these patients.

Methods

This retrospective cohort study used claims data from 2015 to 2019 from the Optum Research Database. The study population included adults (≥ 18 years old) with at least two diagnosis codes for fibrosing ILD during the identification period (1OCT2016 to 31DEC2018). A claim-based algorithm for disease progression was used to identify patients likely to have a progressive fibrotic phenotype using progression proxies during the identification period. Index date was the first day of progression proxy identification after fibrosing ILD diagnosis. Patients were required to have continuous enrollment for 12 months before (baseline) and after (follow-up) index date. Patients with an IPF diagnosis were excluded. Descriptive statistics were used to describe the patient population and care patterns.

Results

11,204 patients were included in the study. Mean age of the patient population was 72.7 years, and 54.5% were female. Unclassified ILDs (48.0%), HP (25.2%) and autoimmune ILDs (16.0%) were the most common ILD types. Other respiratory conditions were prevalent among patients including chronic obstructive pulmonary disease (COPD) (58.9%), obstructive sleep apnea (OSA) (25.0%) and pulmonary hypertension (9.8%). During baseline, 65.3% of all patients had at least one pulmonology visit, this proportion was higher during follow-up, at 70.6%. Baseline and follow-up use for HRCT were 39.9% and 48.8%, and for pulmonary function tests were 43.7% and 48.5% respectively. Use of adrenal corticosteroids was higher during follow-up than during baseline (62.5% vs. 58.0%). Anti-inflammatory and immunosuppressive medication classes were filled by a higher percentage of patients during follow-up than during baseline.

Conclusions

Comprehensive testing is essential for diagnosis of a progressive phenotype condition, but diagnostic tests were underutilized. Patients with this condition frequently were prescribed anti-inflammatory and immunosuppressive medications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01953-9.

Impact of Palliative Care in End-of-Life of Fibrotic Interstitial Lung Disease Patients

Background: Interstitial lung disease (ILD) is associated with poor quality of life (QoL) and high symptom burden. Studies evaluating the benefits of palliative care examined mainly idiopathic pulmonary fibrosis (IPF) patients. We aim to examine the impact of palliative care on a broader group of fibrotic ILD patients. Methods: Single center retrospective cohort study comparing deceased ILD patients who received outpatient palliative care services (palliative-intervention group) against a usual care group. Results: Of 63 subjects, 26 (41%) were in the palliative-intervention group and 37 (59%) in the usual care group. Median time to palliative care referral was 8.6 (IQR .3-21.2) months. Dyspnea-related disability was greater in the palliative-intervention group [mMRC dyspnea score 3.5(IQR 2-4) vs 2(IQR 2-4), P = .039], with more patients requiring long term oxygen therapy (70% vs 30%, P < .001). There was no difference in the median number of hospitalizations or length of stay in the last 6 months of life. Patients in the palliative-intervention group had a higher uptake of advance care planning (ACP) (39% vs 11%, P = .014), lower frequency of intensive care unit (ICU) admissions (5% vs 19%, P = .102) and were prescribed more opioids (96% vs 27%, P < .001) and benzodiazepines (39% vs 14%, P = .022). The palliative-intervention group experienced a longer median survival of 23.9 months (95% confidence interval [CI] 14.1-33.7) compared to the usual group (11.4 months [95% CI 5.4-17.3] (log-rank test: P = .023). Male gender was a strong predictor of 1-year mortality. Conclusions: The palliative-intervention group received earlier pharmacologic intervention for symptom relief. Healthcare utilization was not increased despite greater dyspnea-related disability.

Healthcare Resource Utilization and Related Costs in Chronic Fibrosing Interstitial Lung Diseases with a Progressive Phenotype: A US Claims Database Analysis

INTRODUCTION

We aimed to describe healthcare resource utilization (HCRU) patterns and costs in patients with fibrosing interstitial lung disease (ILD) and those with a progressive phenotype of fibrosing ILD in a US claims database.

METHODS

Data from the IBM^® MarketScan^® databases (1 October 2011-30 September 2015) were used. Diagnosis codes documented on medical claims on two occasions (without any claims during the 12 months prior) identified patients with incident fibrosing ILD. Patients with chronic fibrosing ILD with a progressive phenotype were identified by proxies for progression. Patients aged ≥ 18 years with 365 days of continuous coverage before the index date were eligible for inclusion. Data were analyzed for 12 months prior to identification of fibrosing ILD/progressive phenotype (baseline) and 12 months after (follow-up). Outcomes included treatment patterns, outpatient and inpatient claims, and costs.

RESULTS

We identified 23,577 patients with incident fibrosing ILD and 14,722 with the progressive phenotype. Follow-up data were available for 9986 and 5840 patients, respectively. The most frequent ILD-related medications during baseline were corticosteroids (49.4% and 56.6%). Mean (± standard deviation [SD]) annualized number of outpatient claims was 30.0 (± 26.4) and 34.1 (± 27.7) in the baseline period and 36.2 (± 28.6) and 41.9 (± 30.2) in the follow-up in fibrosing ILD and with a progressive phenotype, respectively. Mean (SD) number of all-cause hospitalizations was 0.5 (± 1.1) and 0.7 (± 1.2) during baseline and 0.6 (± 1.1) and 0.7 (± 1.2) during follow-up. Mean (SD) total costs were $40,907 (± 92,496) and $49,561 (± 98,647) during baseline and $46,157 (± 102,858) and $54,215 (± 116,833) during follow-up. Inpatient mortality during follow-up was 53.50 and 77.44 per 1000 patient-years.

CONCLUSION

HCRU and costs were high in patients with chronic fibrosing ILD with a progressive phenotype, likely reflecting the disease severity and the need for close monitoring and acute care. Outpatient claims accounted for a substantial proportion of the total costs.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Acute exacerbation is a major cause of morbidity and mortality in patients with idiopathic pulmonary fibrosis. Although the real nature of it is still not clear and there is no proven effective therapy, progress has been made since the consensus definition and diagnostic criteria were proposed. The trial results of several new innovative therapies in idiopathic pulmonary fibrosis have suggested a potential for benefit in acute exacerbation of idiopathic pulmonary fibrosis, leading to double blind randomized clinical trials in this area. This article reviews the present knowledge on acute exacerbation of idiopathic pulmonary fibrosis, focusing on the triggering factors and treatment.

Effect of anti-reflux therapy on pulmonary function in idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

Current guideline conditionally recommends regular use of anti-reflux medication in idiopathic pulmonary fibrosis (IPF). However, the effect of anti-reflux therapy in this group remains controversial. We systematically reviewed literatures to evaluate whether anti-reflux therapy could ameliorate pulmonary function in IPF.

Methods

We performed electronic search in PubMed, Embase and CENTRAL (Cochrane Central Register of Controlled Trials) to identify original articles published in English language. We included randomized controlled trials (RCTs) and observational studies regarding anti-reflux therapy on pulmonary function in IPF. Qualitative and quantitative analyses were conducted. In quantitative analysis, the inverse-variance method with fixed-effect model was used to analyze pooled data.

Results

Fifteen studies (2 RCTs and 13 observational studies) including 3,891 patients with IPF were included. Pooled analysis suggested that anti-reflux therapy did not improve forced vital capacity (FVC)% predicted [mean difference (MD) =0.88, 95% confidence interval (CI): −0.22 to 1.98, P=0.12, I² =0%, 8 studies, n=3,076], diffusing capacity of the lung for carbon monoxide (DLCO) % predicted (MD =0.75, 95% CI: −0.13 to 1.62, P=0.10, I² =0%, 8 studies, n=3,073), and FVC decline (MD =0.02, 95% CI: −0.01 to 0.04, P=0.29, I² =17%, 5 studies, n=1,586) in IPF.

Discussion

Anti-reflux therapy may not ameliorate pulmonary function in IPF. However, adequately powered studies are warranted to validate the present findings.

The psychometric properties of the King's Brief Interstitial Lung Disease questionnaire and thresholds for meaningful treatment response in patients with progressive fibrosing interstitial lung diseases

Background

There is a lack of fully validated patient-reported outcome measures for progressive fibrosing interstitial lung disease (ILD). We aimed to validate the King's Brief Interstitial Lung Disease (K-BILD) questionnaire for measuring health-related quality of life (HRQoL) in these patients. We also aimed to estimate the meaningful change threshold for interpreting stabilisation of HRQoL as a clinical end-point in progressive fibrosing ILD, where the current goal of treatment is disease stability and slowing progression.

Methods

This analysis evaluated data from 663 patients with progressive fibrosing ILD other than idiopathic pulmonary fibrosis from the INBUILD trial. Validation of the measurement properties was assessed for internal consistency, test–retest reliability, construct validity, known-groups validity and responsiveness. We calculated meaningful change thresholds for treatment response using anchor-based (within-patient) and distribution-based methods.

Results

K-BILD had strong internal consistency (Cronbach's α was 0.94 for total score, 0.88 for breathlessness and activities, 0.91 for psychological, and 0.79 for chest symptoms). The test–retest reliability intraclass correlation coefficient was 0.74 for K-BILD total score. K-BILD demonstrated weak correlations with forced vital capacity (FVC) percent predicted. Known-groups validity showed significant differences in K-BILD scores for patient groups with different disease severity based on use of supplemental oxygen or baseline FVC % pred (≤70% or >70%). We estimated a meaningful change threshold of ≥ –2 units for K-BILD total score for defining patients who remain stable/improved versus those with progressive deterioration.

Conclusions

Our results validate K-BILD as a tool for assessing HRQoL in patients with progressive fibrosing ILD and set a meaningful change threshold of ≥ –2 units for K-BILD total score.

The King's Brief Interstitial Lung Disease (K-BILD) questionnaire is a valid tool for measuring health-related quality of life in patients with progressive fibrosing ILD. The meaningful change threshold for K-BILD total score is ≥ −2 units.https://bit.ly/3v9rU0M

IPF-Fibroblast Erk1/2 Activity Is Independent from microRNA Cluster 17-92 but Can Be Inhibited by Treprostinil through DUSP1

Idiopathic pulmonary fibrosis (IPF) is a progressive terminal lung disease, and therapies aim to block fibrosis. Fibroblast proliferation is controlled by C/EBP-β, microRNA cluster 17-92 (miR17-92), and Erk1/2 mitogen-activated protein kinase. This study assessed the role of miR17-92 in IPF-fibroblast proliferation and its modification by treprostinil. Fibroblasts were isolated from eight IPF patients, five interstitial lung fibrosis patients, and seven control lungs. Fibroblasts were stimulated with TGF-β1 over 24 h. The miR17-92 expression was analyzed by RT-qPCR, and protein expression by Western blotting. TGF-β1 upregulated C/EBP-β in all fibroblasts, which was reduced by treprostinil in control-fibroblasts, but not in IPF-fibroblasts. Compared to controls, the guide strands miR-19a-3p, miR-19b-3p, miR-20a-5p, and miR-92a-3p, as well as the passenger strands miR-17-3p, miR-18-3p, miR-19a-1-5p, and miR-92a-5p were significantly increased in IPF-fibroblasts. In controls, TGF-β1 and treprostinil significantly reduced specific miR17-92 members. IPF-fibroblast proliferation was inhibited by treprostinil through increased expression of the Erk1/2 inhibitor DUSP1. These data suggest that proliferation control via miR17-92 and C/EBP-β is disrupted in IPF-fibroblasts. Therefore, the inhibition of early stages of signaling cascades or specific mitogen receptors might be less effective. However, the increased proliferation is sensitive to Erk1/2 inhibition by treprostinil-induced DUSP1.

Progressive Fibrosing Interstitial Lung Diseases: A Current Perspective

Interstitial lung diseases (ILDs) are a large and diverse group of rare and chronic respiratory disorders, with idiopathic pulmonary fibrosis (IPF) being the most common and best-studied member. Increasing interest in fibrosis as a therapeutic target and the appreciation that fibrotic mechanisms may be a treatable target of IPF prompted the development and subsequent approval of the antifibrotics, pirfenidone and nintedanib. The management of ILDs has changed considerably following an understanding that IPF and some ILDs share similar disease behavior of progressive fibrosis, termed “progressive fibrosing phenotype”. Indeed, antifibrotic treatment has shown to be beneficial in ILDs characterized by the progressive fibrosing phenotype. This narrative review summarizes current knowledge in the field of progressive fibrosing ILDs. Here, we discuss the clinical characteristics and pathogenesis of lung fibrosis and highlight relevant literature concerning the mechanisms underlying progressive fibrosing ILDs. We also summarize current diagnostic approaches and the available treatments of progressive fibrosing ILDs and address the optimization of treating progressive fibrosing ILDs with antifibrotics in clinical practice.

Care Delivery Models and Interstitial Lung Disease: The Role of the Specialized Center

Comprehensive interstitial lung disease (ILD) care delivery models have several key components including diagnosis, treatment, monitoring, coordination with other health care providers, patient support/advocacy, education, and research. ILD is rapidly evolving, and specialized centers with ILD-specific expertise have emerged as ways to care for complex patients. The role of the specialized center in care delivery is multifaceted and aimed at improving patient care and advancing the field of ILD. Widespread access to specialized centers is a barrier to ILD care delivery worldwide. Creative and innovative strategies that leverage technology are needed to bridge gaps in ILD care.

Expert Perspective: Management of Refractory Inflammatory Myopathy

The idiopathic inflammatory myopathies (IIMs) are chronic disorders characterized by inflammation in skeletal muscle but also in other organs such as the skin, lungs, joints, gastrointestinal tract, and heart. The effect of immunosuppressive treatment varies between individual patients and between organ manifestations within the same individual. Many patients respond poorly to first-line treatment with glucocorticoids and other immunosuppressive agents such as methotrexate or azathioprine, with symptoms persisting in the muscles, skin, and lungs, leading to refractory disease. Management of refractory IIM is a clinical challenge, and a systematic approach is proposed to better understand the lack of treatment response, in order to guide disease management. The first step in the management of refractory IIM is to recognize whether remaining symptoms are caused by persistent inflammation in the affected tissue or whether the symptoms may be attributable to damage preceding inflammation. Thus, a second diagnostic examination is recommended. Second, in particular for patients with remaining muscle weakness, it is important to ascertain whether the diagnosis of myositis is correct or whether another underlying muscle disorder could explain the symptoms. Third, with confirmation of remaining inflammation in the tissues, a strategy to change treatment needs to be undertaken. Few controlled trials are available to guide our treatment strategies. Furthermore, different subgroups of patients may benefit from different therapies, and different organ manifestations may respond to different therapies. In this context, subgrouping of patients with IIM based on autoantibody profile may be helpful, as there are emerging data from open studies and case series to support the notion of a varying treatment response in different autoantibody-defined subgroups of IIM patients.

Importance of chest HRCT in the diagnostic evaluation of fibrosing interstitial lung diseases

Many conditions result in chronic interstitial lung disease (ILD), being classified as fibrosing ILDs, including idiopathic pulmonary fibrosis, connective tissue diseases, sarcoidosis, and fibrotic hypersensitivity pneumonitis. HRCT plays an important role in the clinical evaluation of fibrosing ILDs. Current treatment perspectives are encouraging and reinforce the need for HRCT scans of adequate technical quality for early detection of fibrosing ILD. Despite efforts in this regard, the significance and management of imaging findings of early interstitial lung abnormalities have yet to be clarified. After identification of CT findings consistent with fibrosing ILD, radiologists must be able to identify characteristic morphological patterns and, in some cases, features of specific clinical entities. In cases in which HRCT features are not sufficiently specific for a definitive diagnosis, HRCT can aid in selecting the best site for surgical lung biopsy. CT follow-up is useful for identifying progressive fibrosing ILDs and detecting complications unrelated to the underlying disease, including infections, acute exacerbations, and neoplasms. Automated quantification tools have clinical applicability and are likely to be available for use in imaging analysis in the near future. In addition, incorporation of CT evaluation into scoring systems based on clinical and functional parameters for staging fibrosing disease is likely to become valuable in determining prognosis. Knowledge of the clinical applications of CT evaluation is essential for specialists managing patients with fibrosing ILD and can have a positive impact on the clinical course of the disease.

Antifibrotic Therapy: Is There a Role in Myositis-Interstitial Lung Disease?

Interstitial lung disease (ILD) is a cause of substantial morbidity and mortality amongst autoimmune diseases, including myositis. Despite first-line therapy with immunosuppression, many inflammatory ILDs advance to a fibrotic stage. In such patients, progressive fibrosis may be amenable to treatment with antifibrotic medications, which were initially studied and approved for the treatment of idiopathic pulmonary fibrosis. We here review the available data that support the use of antifibrotics in connective tissue diseases and progressive fibrosing ILDs. There is now a growing body of evidence in both large randomized clinical trials and on the evolving pathophysiologic pathways to support the use of antifibrotics in select patients with autoimmune ILD and a fibrotic phenotype. Further study of antifibrotics in combination with immunosuppressive medications, and in the myositis-ILD population, is needed.

Profibrotic function of pulmonary group 2 innate lymphoid cells is controlled by regnase-1

Regnase-1 is an RNase critical for post-transcriptional control of pulmonary immune homeostasis in mice by degrading immune-related mRNAs. However, little is known about the cell types Regnase-1 controls in the lung, and its relevance to human pulmonary diseases.Regnase-1-dependent changes in lung immune cell types were examined by a competitive bone marrow transfer mouse model, and group 2 innate lymphoid cells (ILC2s) were identified. Then the associations between Regnase-1 in ILC2s and human diseases were investigated by transcriptome analysis and a bleomycin-induced pulmonary fibrosis mouse model. The clinical significance of Regnase-1 in ILC2s was further assessed using patient-derived cells.Regnase-1-deficiency resulted in the spontaneous proliferation and activation of ILC2s in the lung. Intriguingly, genes associated with pulmonary fibrosis were highly upregulated in Regnase-1-deficient ILC2s compared with wild-type, and supplementation of Regnase-1-deficient ILC2s augmented bleomycin-induced pulmonary fibrosis in mice. Regnase-1 suppresses mRNAs encoding transcription factors Gata3 and Egr1, which are potent to regulate fibrosis-associated genes. Clinically, Regnase-1 protein levels in ILC2 negatively correlated with the ILC2 population in bronchoalveolar lavage fluid. Furthermore, idiopathic pulmonary fibrosis (IPF) patients with ILC2s >1500 cells·mL^-1 peripheral blood exhibited poorer prognosis than patients with lower numbers, implying the contribution of Regnase-1 in ILC2s for the progression of IPF.Collectively, Regnase-1 was identified as a critical post-transcriptional regulator of the profibrotic function of ILC2s both in mouse and human, suggesting that Regnase-1 may be a novel therapeutic target for IPF.

Current monitoring and treatment of progressive fibrosing interstitial lung disease: a survey of physicians in Japan, the United States, and the European Union

OBJECTIVE

To understand assumptions about and approaches to interstitial lung disease (ILD), including those of the progressive phenotype (progressive fibrosing ILD), this multinational survey assessed physicians' attitudes toward, knowledge of, and management strategies for progressive fibrosing ILD.

METHODS

This internet-based survey of physicians was conducted between November 2018 and February 2019. Practical management strategies for progressive fibrosing ILD, and current approaches to the assessment and treatment of ILD, were compared between countries/regions (Japan vs. United States and European Union) and specialties (pulmonologists vs. rheumatologists).

RESULTS

The survey was completed by 574 respondents. Compared with Western countries, the progressive fibrosing phenotype concept was not widely understood by Japanese respondents, with no notable differences in the understanding of this phenotype between pulmonologists and rheumatologists. Across all regions, pulmonary function tests, diffusing capacity of the lungs for carbon monoxide assessments, and pulse oximeter measurements were commonly performed at intervals of ≤6 months. In general, physicians in the United States and European Union preferred physiologic approaches for follow-up, while those in Japan preferred imaging and blood monitoring. Compared with rheumatologists, pulmonologists performed more frequent monitoring of autoimmune ILDs, and the differences between specialties were most pronounced in Japan. Regional differences in treatment approaches were observed, probably reflecting the local availability of agents and healthcare environments.

CONCLUSIONS

Awareness and management of progressive fibrosing ILD varied between specialties and regions, highlighting an unmet need for standardized diagnosis, treatment guidelines, and specialist education in this area.

Mechanisms of progressive fibrosis in connective tissue disease (CTD)-associated interstitial lung diseases (ILDs)

Interstitial lung diseases (ILDs), which can arise from a broad spectrum of distinct aetiologies, can manifest as a pulmonary complication of an underlying autoimmune and connective tissue disease (CTD-ILD), such as rheumatoid arthritis-ILD and systemic sclerosis (SSc-ILD). Patients with clinically distinct ILDs, whether CTD-related or not, can exhibit a pattern of common clinical disease behaviour (declining lung function, worsening respiratory symptoms and higher mortality), attributable to progressive fibrosis in the lungs. In recent years, the tyrosine kinase inhibitor nintedanib has demonstrated efficacy and safety in idiopathic pulmonary fibrosis (IPF), SSc-ILD and a broad range of other fibrosing ILDs with a progressive phenotype, including those associated with CTDs. Data from phase II studies also suggest that pirfenidone, which has a different-yet largely unknown-mechanism of action, may also have activity in other fibrosing ILDs with a progressive phenotype, in addition to its known efficacy in IPF. Collectively, these studies add weight to the hypothesis that, irrespective of the original clinical diagnosis of ILD, a progressive fibrosing phenotype may arise from common, underlying pathophysiological mechanisms of fibrosis involving pathways associated with the targets of nintedanib and, potentially, pirfenidone. However, despite the early proof of concept provided by these clinical studies, very little is known about the mechanistic commonalities and differences between ILDs with a progressive phenotype. In this review, we explore the biological and genetic mechanisms that drive fibrosis, and identify the missing evidence needed to provide the rationale for further studies that use the progressive phenotype as a target population.

Progressive fibrosing interstitial lung diseases: A new concept and indication of nintedanib

Many interstitial lung diseases (ILDs) are characterized by chronic progressive fibrosis. The antifibrotic agents may prevent disease progression of these diseases. Nintedanib is a triple tyrosine kinase inhibitor and has an antifibrotic effect. The proven beneficial effects of nintedanib in idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc)-associated ILD, nintedanib was intended for use in many other fibrotic lung diseases consistent with the concept described below. With this trial, the concept and definition of progressive fibrosing ILD (PF-ILD) were created, a type of fibrosing diseases that progresses with fibrosis measured in forced vital capacity and high-resolution CT findings and worsening of respiratory symptoms at a certain rate or faster. PF-ILDs are composed of idiopathic interstial pneumonias such as non-specific interstitial pneumonia and unclassifiable interstitial pneumonia and inhalation lung diseases such as chronic hypersensitivity pneumonia and connective tissue disease-associated ILD such as rheumatoid arthritis-related ILD and SSc-related ILD and sarcoidosis and so on. Nintedanib significantly reduced the annual rate of decline in forced vital capacity over 52 weeks compared with placebo. Nintedanib received marketing approval in the United States and Japan for the treatment of PF-ILDs. This review summarizes the new concept of PF-ILDs and effectiveness of nintedanib to PF-ILDs and discussion points to be solved in the future when using nintedanib for PF-ILDs.

Idiopathic pulmonary fibrosis and pulmonary hypertension: Heracles meets the Hydra

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease where the additional presence of pulmonary hypertension (PH) reduces survival. In particular, the presence of coexistent pulmonary vascular disease in patients with advanced lung parenchymal disease results in worse outcomes than either diagnosis alone. This is true with respect to the natural histories of these diseases, outcomes with medical therapies, and even outcomes following lung transplantation. Consequently, there is a striking need for improved treatments for PH in the setting of IPF. In this review, we summarize existing therapies from the perspective of molecular mechanisms underlying lung fibrosis and vasoconstriction/vascular remodelling and discuss potential future targets for pharmacotherapy. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Progressive Fibrosing Interstitial Lung Diseases: Prevalence and Characterization in Two Italian Referral Centers

<b><i>Background:</i></b> The prevalence and natural history of progressive fibrosing interstitial lung diseases (PF-ILDs), and their response to commonly used treatments in real life are largely unknown. <b><i>Objectives:</i></b> The aim of the study was to describe the prevalence, clinical characteristics, management, and outcomes of PF-ILD patients attending 2 Italian referral centers (San Gerardo Hospital, Monza, and San Giuseppe Hospital, Milan) from January 1, 2011, to July 31, 2019. <b><i>Methods:</i></b> From a cohort of non-idiopathic pulmonary fibrosis fibrosing ILD patients with at least 2-year follow-up, we selected only those with progressive disease, defined as per the INBUILD trial, collecting their demographical, clinical, and functional data. <b><i>Results:</i></b> Out of the 245 fibrosing ILD patients, 75 (31%) were classified as PF-ILDs (median age 66 years, 60% males), most frequently idiopathic non-specific interstitial pneumonia (28%), followed by connective tissue disease-associated ILD (20%), chronic hypersensitivity pneumonitis, and sarcoidosis (17% each). Most patients (81%) were categorized as PF-ILDs because of forced vital capacity (FVC) decline ≥10%, while 19% experienced a marginal FVC decline (between 5 and 10%) associated with worsening respiratory symptoms or increasing extent of fibrotic changes on high-resolution computed tomography. Disease progression occurred after a median of 18 months from ILD diagnosis. The vast majority (93%) of PF-ILD patients received prednisolone, alone (40%) or associated with steroid-sparing agents (52%), and 35% of treated patients developed treatment-related adverse events. After ILD progression, the median survival was 3 (interquartile range (IQR) 2–5) years, with a 2- and 3-year mortality rate of 4 and 20%, respectively. <b><i>Conclusions:</i></b> In a real-life setting, approximately one-third of the fibrosing ILD patients showed a progressive course despite treatment. Studies aimed to better phenotype this subgroup of patients are needed.

Low-Dose of Intrapulmonary Pirfenidone Improves Human Transforming Growth Factorβ1-Driven Lung Fibrosis

Idiopathic pulmonary fibrosis is a chronic, progressive, and lethal lung disease of unknown etiology. Antifibrotic drugs, including pirfenidone, are currently used for the treatment of the disease. The oral administration of pirfenidone is an effective therapy, as demonstrated by several clinical trials, although it causes severe adverse events in some patients. We hypothesized that low-dose intrapulmonary delivery of pirfenidone is effective in human transforming growth factorβ1-driven pulmonary fibrosis. To demonstrate our hypothesis, we compared the therapeutic efficacy of varying doses of pirfenidone administered by oral and intranasal routes in a human transforming growth factor-β1 transgenic mouse with established pulmonary fibrosis. We found similar amelioration of lung cell infiltration, inflammatory and fibrotic cytokines, lung fibrosis score, and hydroxyproline content in mice with human transforming growth factor-β1-mediated pulmonary fibrosis treated with low-dose intranasal pirfenidone and high-dose oral pirfenidone. This study showed that pirfenidone is a potent inhibitor of human transforming growth factor-β1-driven lung fibrosis and that intrapulmonary delivery of low-dose pirfenidone produces therapeutic responses equivalent to high-dose of oral pirfenidone.

Identification of a Missense Mutation in the Surfactant Protein A2 Gene in a Chinese Family with Interstitial Lung Disease

Interstitial lung disease (ILD) is a large group of disorders, most of which lead to progressive scarring of lung tissue. The scarring associated with ILD eventually affects your ability to breathe and get enough oxygen into your bloodstream. The typical symptoms of ILD are shortness of breath at rest or aggravated by exertion and dry cough. In this study, we enrolled a family with ILDs from central south region of China. Three patients suffered from repeated cough and shortness of breath. The high resolution computed tomography (HRCT) testing further confirmed the diagnosis of interstitial lung lesions. Whole exome sequencing (WES) and Sanger sequencing were applied to detect the genetic lesion of the family. By employing WES, a novel heterozygous mutation (NM_001098668: c.554C>T/p.A185V) of surfactant protein A2 (SFTPA2) was identified in the affected individuals and absent in the healthy members. Bioinformatics analysis predicted that this mutation is disease-causing mutation and located in an evolutionarily conserved site of SFTPA2 protein. The novel mutation may disrupt the stability of SFTPA2 protein and induce endoplasmic reticulum stress, finally leading to ILD under the influence of microorganisms. Our study not only expands the spectrum of SFTPA2 mutations but also helps the family members to mitigate ILD risk factors. The study also supplements and improves genetic testing strategies and ILD risk estimation methodologies for China.

Assessment and Management of Occupational Hypersensitivity Pneumonitis

The diagnosis and treatment of occupational hypersensitivity pneumonitis (OHP) remain complex and challenging in the absence of diagnostic gold standards or clinical guidelines. This review provides an update of the recent literature regarding the different presentations of OHP and the diagnostic yield and value of the diagnostic tests currently available, which include occupational and medical history, laboratory tests (serum-specific immunoglobulins, environmental sampling), imaging, bronchoalveolar lavage, transbronchial biopsy, transbronchial cryobiopsy, surgical lung biopsy, and specific inhalation challenges. These tools provide a precise differential diagnosis within the framework of interstitial lung diseases. However, among the chronic fibrotic forms, distinguishing OHP from sarcoidosis, nonspecific interstitial pneumonia and idiopathic pulmonary fibrosis remains a diagnostic challenge. Avoidance of exposure is pivotal for OHP management, whereas corticosteroids are fundamental in the pharmacological approach to this disease. In addition, studies describing the long-term benefits of immunosuppressive and antifibrotic agents have increased the use of these treatments in OHP.

Time taken from primary care referral to a specialist centre diagnosis of idiopathic pulmonary fibrosis: an opportunity to improve patient outcomes?

The care of patients with idiopathic pulmonary fibrosis (IPF) has been transformed by the widespread approval of antifibrotic therapies [1]. Within primary care-based healthcare systems, the diagnosis of IPF and commencement of antifibrotic therapy typically requires a patient referral from a primary care physician to a respiratory physician in secondary care, with referral then made to a specialist interstitial lung disease (ILD) centre [2]. Following ILD centre review and multidisciplinary team (MDT) discussion, a diagnosis of IPF is made and antifibrotic therapy may be commenced.

For patients with IPF, length of time in healthcare systems prior to review in an ILD clinic reflects disease severity and may impact upon patient outcomehttps://bit.ly/2TkO26r

Delayed contrast dynamics as marker of regional impairment in pulmonary fibrosis using 5D MRI - a pilot study

OBJECTIVE

To analyse delayed contrast dynamics of fibrotic lesions in interstitial lung disease (ILD) using five dimensional (5D) MRI and to correlate contrast dynamics with disease severity.

METHODS

20 patients (mean age: 71 years; M:F, 13:7), with chronic fibrosing ILD: n = 12 idiopathic pulmonary fibrosis (IPF) and n = 8 non-IPF, underwent thin-section multislice CT as part of the standard diagnostic workup and additionally MRI of the lung. 2 min after contrast injection, a radial gradient echo sequence with golden-angle spacing was acquired during 5 min of free-breathing, followed by 5D image reconstruction. Disease was categorized as severe or non-severe according to CT morphological regional severity. For each patient, 10 lesions were analysed.

RESULTS

IPF lesions showed later peak enhancement compared to non-IPF (severe: p = 0.01, non-severe: p = 0.003). Severe lesions showed later peak enhancement compared to non-severe lesions, in non-IPF (p = 0.04), but not in IPF (p = 0.35). There was a tendency towards higher accumulation and washout rates in IPF compared to non-IPF in non-severe disease. Severe lesions had lower washout rate than non-severe ones in both IPF (p = 0.003) and non-IPF (p = 0.005). Continuous contrast agent accumulation, without washout, was found only in IPF lesions.

CONCLUSIONS

Contrast agent dynamics are influenced by type and severity of pulmonary fibrosis, which might enable a more thorough characterisation of disease burden. The regional impairment is of particular interest in the context of antifibrotic treatments and was characterised using a non-invasive, non-irradiating, free-breathing method.

ADVANCES IN KNOWLEDGE

Delayed contrast enhancement patterns allow the assessment of regional lung impairment which could represent different disease stages or phenotypes in ILD.

The extended utility of antifibrotic therapy in progressive fibrosing interstitial lung disease

INTRODUCTION

The approval of two antifibrotic treatment agents for delaying disease progression in idiopathic pulmonary fibrosis (IPF), has prompted researchers to look at expanding the role of antifibrotic therapy to other fibrosing interstitial lung disease (ILD). Similarities in the pathological mechanisms that lead to the development of IPF have been implicated in other progressive fibrosing ILD (PF-ILD) such as chronic hypersensitivity pneumonitis, connective tissues disease associated ILD, sarcoidosis, occupational ILD and idiopathic non-specific interstitial pneumonia (iNSIP). This has prompted the rationale to use antifibrotic therapy to target similar molecular pathways in these diseases.

AREAS COVERED

This review will summarise the available evidence from randomised controlled trials that have evaluated the use of antifibrotic therapy in PF-ILD outside the realm of IPF.

EXPERT OPINION

There is promising data for antifibrotic therapy as a therapeutic option for non IPF PF-ILD. The new therapy option does provide some challenges that need to be addressed such as timing of initiation of therapy, clarifying the strategy for overlap or combination with existing immunosuppressive therapies and potential drug interactions. There is an unmet need to determine accurate predictors of disease progression to allow early intervention for the preservation of lung function and mortality reduction.