Progressive Fibrosing Phenotype Research Articles

Targeting Progression in Pulmonary Fibrosis: An Overview of Underlying Mechanisms, Molecular Biomarkers, and Therapeutic Intervention.

Interstitial lung diseases comprise a heterogenous range of diffuse lung disorders, potentially resulting in pulmonary fibrosis. While idiopathic pulmonary fibrosis has been recognized as the paradigm of a progressive fibrosing interstitial lung disease, other conditions with a progressive fibrosing phenotype characterized by a significant deterioration of the lung function may lead to a burden of significant symptoms, a reduced quality of life, and increased mortality, despite treatment. There is now evidence indicating that some common underlying biological mechanisms can be shared among different chronic fibrosing disorders; therefore, different biomarkers for disease-activity monitoring and prognostic assessment are under evaluation. Thus, understanding the common pathways that induce the progression of pulmonary fibrosis, comprehending the diversity of these diseases, and identifying new molecular markers and potential therapeutic targets remain highly crucial assignments. The purpose of this review is to examine the main pathological mechanisms regulating the progression of fibrosis in interstitial lung diseases and to provide an overview of potential biomarker and therapeutic options for patients with progressive pulmonary fibrosis.

The evolution of in vitro models of lung fibrosis: promising prospects for drug discovery.

Lung fibrosis is a complex process, with unknown underlying mechanisms, involving various triggers, diseases and stimuli. Different cell types (epithelial cells, endothelial cells, fibroblasts and macrophages) interact dynamically through multiple signalling pathways, including biochemical/molecular and mechanical signals, such as stiffness, affecting cell function and differentiation. Idiopathic pulmonary fibrosis (IPF) is the most common fibrosing interstitial lung disease (fILD), characterised by a notably high mortality. Unfortunately, effective treatments for advanced fILD, and especially IPF and non-IPF progressive fibrosing phenotype ILD, are still lacking. The development of pharmacological therapies faces challenges due to limited knowledge of fibrosis pathogenesis and the absence of pre-clinical models accurately representing the complex features of the disease. To address these challenges, new model systems have been developed to enhance the translatability of preclinical drug testing and bridge the gap to human clinical trials. The use of two- and three-dimensional in vitro cultures derived from healthy or diseased individuals allows for a better understanding of the underlying mechanisms responsible for lung fibrosis. Additionally, microfluidics systems, which replicate the respiratory system's physiology ex vivo, offer promising opportunities for the development of effective therapies, especially for IPF.

Biomarkers of Progressive Fibrosing Interstitial Lung Diseases

Despite adequate therapy, interstitial lung diseases (ILD) can cause progressive scarring of lung tissue. This type of ILD is known as progressive fibrosing ILD (PF­-ILD). The challenge in diagnosing PF-­ILD lies in the lack of uniformly accepted criteria for a progressive fibrosing phenotype. Most authors use criteria based on clinical features and assessment of functional imaging and radiological findings over time. However, forced vital capacity (FVC) measurement is limited by its variability, and the follow­up lasts 1­2 years. The above diagnostic challenges prevent from prescribing early adequate therapy in patients with progressive ILD, indicting the need to search for new biomarkers of the progressive fibrosing phenotype. We review the most studied and informative biomarkers of fibrosis progression in patients with ILD.

Interstitial lung disease with and without progressive fibrosing phenotype in patients with idiopathic inflammatory myopathies: data from a large multicentric cohort

ObjectivesPatients with connective tissue diseases can develop interstitial lung disease (ILD), leading to a progressive fibrosing ILD (PF-ILD) phenotype in some cases. We aimed to investigate the occurrence of PF-ILD...

Progressive fibrotic interstitial lung disease.

Many interstitial lung diseases (ILDs) share mechanisms that result in a progressive fibrosing phenotype. In Brazil, the most common progressive fibrosing interstitial lung diseases (PF-ILDs) are chronic hypersensitivity pneumonitis, idiopathic pulmonary fibrosis, unclassified ILD, and connective tissue diseases. PF-ILD is seen in approximately 30% of patients with ILD. Because PF-ILD is characterized by disease progression after initiation of appropriate treatment, a diagnosis of the disease resulting in fibrosis is critical. Different criteria have been proposed to define progressive disease, including worsening respiratory symptoms, lung function decline, and radiological evidence of disease progression. Although the time elapsed between diagnosis and progression varies, progression can occur at any time after diagnosis. Several factors indicate an increased risk of progression and death. In the last few years, antifibrotic drugs used in patients with idiopathic pulmonary fibrosis have been tested in patients with PF-ILD. The effects of nintedanib and placebo have been compared in patients with PF-ILD, a mean difference of 107.0 mL/year being observed, favoring nintedanib. The U.S. Food and Drug Administration and the Brazilian Health Regulatory Agency have approved the use of nintedanib in such patients on the basis of this finding. Pirfenidone has been evaluated in patients with unclassified ILD and in patients with other ILDs, the results being similar to those for nintedanib. More studies are needed in order to identify markers of increased risk of progression in patients with ILD and determine the likelihood of response to treatment with standard or new drugs.

Real world experience with nintedanib in connective tissue disease-related interstitial lung disease: a retrospective cohort study.

Various connective tissue diseases tend to affect specific organs, lungs being the organ with the most serious repercussions and consequences. The diagnosis of interstitial lung disease makes the treatment more difficult and worsens long-term prognosis and overall survival. Positive results from the registration studies of nintedanib led to approval of the drug for the treatment of idiopathic pulmonary fibrosis and chronic fibrosing interstitial lung diseases in connective tissue diseases. After registration, real-world data on the use of nintedanib are being collected in everyday clinical practise.The objective of the study was to collect and analyse real world experience gathered after the registration of nintedanib for the treatment of CTD-ILD and to show if the positive results collected from a homogeneous and "representative" study population can be applied to everyday clinical practice.We are presenting a retrospective observational case-series study of patients treated with nintedanib from the three largest Croatian centers specialised in the treatment of connective tissue diseases with interstitial lung diseases.Stabilisation or improved of lung function tests was reported in 68% of patients when changes in predicted FVC were observed and in 72% of patients when changes in DLco were analysed. Almost all of the reported patients (98%) were treated with nintedanib as an add-on drug to immunosuppressants. The most common side-effects were gastrointestinal symptoms and abnormal liver function tests in less extent.Our real-world data confirm the tolerability, efficacy and similar side-effects of nintedanib as reported in pivotal trials. Key Points • Interstitial lung disease is a common manifestation of several connective tissue diseases and its progressive fibrosing phenotype contributes to high mortality rate and many unmet needs regarding the treatment remain. • Registration studies of nintedanib obtained sufficient data and positive results to support approval of the drug. • Real-world evidence from our CTD-ILD centres confirm the clinical trial data regarding efficacy, tolerability and safety of nintedanib.

Prognostic biomarkers of progressive pulmonary fibrosis in patients with interstitial lung diseases

A high proportion of patients with various interstitial lung diseases (ILD) develop progressive pulmonary fibrosis (PLF) associated with a deterioration in the quality of life, a decrease in functional status and early mortality. PLF is diagnosed in patients with ILD of known or unknown etiology other than idiopathic pulmonary fibrosis (ILF), who have radiological signs of pulmonary fibrosis, and at least two of the three criteria for progression, including clinical, functional and radiological indicators that have arisen over the past year in the absence of alternative causes of deterioration. Subtypes of ILD that are at risk of developing a progressive fibrosing phenotype include ILD associated with connective tissue diseases, such as rheumatoid arthritis and systemic scleroderma; sarcoidosis; hypersensitive pneumonitis, occupational lung diseases. In 2022, new criteria for the diagnosis of PLF appeared. The existing evidence of common pathogenesis mechanisms leading to progressive pulmonary fibrosis suggests the presence of uniform biomarkers of disease activity for a wide range of diseases. Pulmonary fibrosis is initiated by microinjuries of the alveolar epithelium of various etiologies, in the future its progression includes similar pathophysiological mechanisms, which suggests the presence of uniform biomarkers of disease activity for a wide range of diseases. Biomarkers can help not only identify patients at risk of progression, but also allow monitoring the early response to treatment. Biomarker research to date has identified a number of molecular markers that predict the presence of the disease, prognosis and/or response to treatment. The creation of national and international registries allows for long-term monitoring of patients with PLF, to answer questions about the long-term effectiveness of treatment. To date, a number of molecular factors that claim to be predictors are being discussed, allowing to verify the diagnosis, determine the prognosis and response to therapy.

Prediction of progressive pulmonary fibrosis in patients with anti-synthetase syndrome-associated interstitial lung disease

ObjectiveInterstitial lung disease (ILD) is a common extramuscular manifestation of the anti-synthetase syndrome (ASS). Patients with ASS-ILD are at risk in developing a progressive fibrosing phenotype despite appropriate treatments. This study investigated the risk factors and the predictive value of multiple risk factors for progressive pulmonary fibrosis (PPF) in patients with ASS-ILD.MethodsNinety patients with a diagnosis of ASS and evidence of ILD on high-resolution computed tomography (HRCT) were recruited. Among them, 72 participants completed follow-up for more than 12 months. These patients were further divided into a PPF-ASS group (n = 18) and a non-PPF-ASS group (n = 54). Logistic regression analysis was performed to investigate the risk factors for PPF. The predictive value of the combined risk factors for predicting PPF were analyzed by a ROC curve.ResultsThe PPF-ASS group had a higher rate of positive non-Jo-1 antibodies, a significantly higher neutrophil-to-lymphocyte ratio (NLR) and serum lactate dehydrogenase (LDH), and a significantly lower PaO2/FiO2 ratio and diffusing capacity for carbon monoxide (DLCO%pred) than the non-PPF-ASS group. In addition, elevated serum Krebs von den Lungen-6 (KL-6) level and reticular opacities were significantly more common, and corticosteroid monotherapy at onset was administered more frequently in the PPF-ASS group. The median duration of follow-up was 37.4 months, survival was poorer in the PPF-ASS group, and the overall survival was 88.9%. Multivariate regression analysis further revealed that positive non-Jo-1 antibodies, NLR, and KL-6 were independent risk factors for PPF. These combined indexes had good accuracy (area under the curve = 0.874) in predicting PPF in patients with ASS-ILD.ConclusionPositive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors for PPF in patients with ASS-ILD. Monitoring these markers can potentially predict PPF in this group of patients.Key Points• Positive non-Jo-1 antibodies, NLR, and serum KL-6 are independent risk factors associated with PPF in patients with ASS-ILD.• Monitoring non-Jo-1 antibodies, NLR, and serum KL-6 can potentially predict PPF in patients with ASS-ILD.

Phosphodiesterase 4B inhibition: a potential novel strategy for treating pulmonary fibrosis.

Patients with interstitial lung disease can develop a progressive fibrosing phenotype characterised by an irreversible, progressive decline in lung function despite treatment. Current therapies slow, but do not reverse or stop, disease progression and are associated with side-effects that can cause treatment delay or discontinuation. Most crucially, mortality remains high. There is an unmet need for more efficacious and better-tolerated and -targeted treatments for pulmonary fibrosis. Pan-phosphodiesterase 4 (PDE4) inhibitors have been investigated in respiratory conditions. However, the use of oral inhibitors can be complicated due to class-related systemic adverse events, including diarrhoea and headaches. The PDE4B subtype, which has an important role in inflammation and fibrosis, has been identified in the lungs. Preferentially targeting PDE4B has the potential to drive anti-inflammatory and antifibrotic effects via a subsequent increase in cAMP, but with improved tolerability. Phase I and II trials of a novel PDE4B inhibitor in patients with idiopathic pulmonary fibrosis have shown promising results, stabilising pulmonary function measured by change in forced vital capacity from baseline, while maintaining an acceptable safety profile. Further research into the efficacy and safety of PDE4B inhibitors in larger patient populations and for a longer treatment period is needed.

Interstitial Macrophages Lead Early Stages of Bleomycin-Induced Lung Fibrosis and Induce Fibroblasts Activation.

A progressive fibrosing phenotype is critical in several lung diseases. It is irreversible and associated with early patient mortality. Growing evidence has revealed pulmonary macrophages' role as modulators of the fibrotic processes. The proportion, phenotype, and function of alveolar (AM) and interstitial macrophages (IM) at the early stages of bleomycin-induced pulmonary fibrosis have not been clearly described. In this way, our study aimed to characterize these macrophage populations and investigate the effect on fibroblast activation. C57BL/6 mice were intratracheally injected with bleomycin and were sacrificed at day 3, 5, and 7 for the performance of flow cytometry and fluorescent-activated cell sorting analysis for protein and gene expression quantification. After bleomycin administration, the proportion of IM was significantly higher than that of AM, which showed a decay during the inflammatory phase, and peaked at day 7. At day 7 of the inflammatory phase, AM started shifting their phenotype from M1-like towards M2, while IM showed a M2-like phenotype. Conditioned medium derived from IM sorted at day 7 induced fibroblast activation and differentiation in myofibroblasts in vitro. Our findings indicate that IM are the largest macrophage population at the early stages of experimental pulmonary fibrosis and are secreted mediators able to activate fibroblasts, pointing to macrophage modulation as a potential therapeutic strategy to restrain progressive fibrosing lung disorders.

Criteria for progressive fibrotic hypersensitivity pneumonitis in a Portuguese patient cohort.

Hypersensitivity pneumonitis (HP) is a syndrome caused by sensitisation to inhaled antigens that leads to an abnormal immune response in the airways and lung parenchyma. Some patients previously diagnosed with certain types of fibrotic interstitial lung diseases (f-ILDs), including fibrotic HP (f-HP), are susceptible to develop a progressive fibrosing phenotype (PF-ILD), despite initial state-of-the-art management. To characterise a cohort of patients with a multidisciplinary diagnosis (MTD) of chronic f-HP, who were followed up in an ILD outpatient clinic of a hospital in Portugal, and to assess the prevalence of PF-ILD criteria in these patients. Data were collected from all patients with a definite or provisional diagnosis of f-HP after a multidisciplinary team discussion. Patients were followed up between December 2014 and July 2019. Data included clinical characteristics, high-resolution chest tomography (HRCT) disease patterns, lung function tests, bronchoalveolar lavage and further immunological work-up, biopsy reports (conventional transbronchial lung biopsy, transbronchial lung cryobiopsy or surgical video-assisted thoracoscopic lung biopsy), all ILD multidisciplinary team records and diagnostic confidence levels. Patients were assessed according to PF-ILD criteria as defined in the INBUILD trial. We identified 83 patients with an MTD of HP, who had been followed up for at least 12 months. Of these, 63 (75.9%) were diagnosed with f-HP. Of the 63 f-HP patients, 33.3% (n=21) fulfilled the predefined criteria for PF-HP: 66.7% had a relative decline of ≥10% forced vital capacity (FVC); 5% a relative decline of 5 - 9% FVC, with worsening symptoms or increased fibrosis on HRCT; and 23.8% had worsening respiratory symptoms with radiological progression. This single-centre cohort study demonstrated that a third of f-HP patients presented with PF-ILD, as determined by progression during initial standard-of-care treatment. A usual interstitial pneumonia (UIP)/UIP-like pattern was present in >70% of patients with f-HP, and two-thirds of these patients had an FVC decline of ≥10%. PF-HP patients were also more exacerbation prone. According to recent trial data, this segment of patients can be considered possible candidates for antifibrotic treatment, with a reasonable prospect of effectiveness. Further efforts should focus on refining knowledge of longitudinal behaviour of large multicentric cohorts of f-HP patients, establishing a consensual and uniform definition of progression for use in clinical practice, as well as developing prognostic prediction tools to better (and early) inform the disease course.

Factors associated with interstitial lung disease and the progressive fibrosing phenotype in rheumatoid arthritis–related interstitial lung disease

BackgroundThe risk factors for interstitial lung disease (ILD) in rheumatoid arthritis (RA) are inconsistent among previous studies. Furthermore, the factors associated with the emergence of the recently defined progressive fibrosing (PF) phenotype are unknown. Herein, we analyze the risk factors for ILD in RA. We also analyze the factors associated with a PF phenotype. MethodsWe collected the clinical and laboratory details of subjects with RA with (cases) or without (controls) ILD. Scoring of high-resolution computed tomography (HRCT) features of ILD was performed. We identified the subgroup that developed the PF phenotype during follow-up. We analyzed the factors associated with ILD using logistic regression (primary objective). We also compared the characteristics of ILD subjects with or without the PF phenotype (secondary objective). ResultsWe included 60 subjects (30 cases, 30 controls). Subjects with ILD had higher age, lower body mass index, longer duration of RA, and poorer lung function than the controls. Age (p = 0.007) and the duration of RA (p = 0.049) were the only significant predictors of ILD on univariate and multivariate analysis, respectively. Six (20%) subjects with RA-ILD developed a PF phenotype. These subjects were older, had greater frequency of honeycombing, and higher HRCT scores for honeycombing and aggregate fibrosis than those without the PF phenotype. Among subjects with honeycombing, 41.7% developed the PF phenotype. ConclusionsRA-ILD was associated with the duration of RA and age. Subjects with the PF phenotype were older and had higher honeycombing and fibrosis scores on HRCT chest.

Definition, evaluation and therapy of progressive fibrosing interstitial lung disease associated with rheumatic diseases - a consensus paper of the Romanian Society of Rheumatology and Romanian Society of Pneumology

Interstitial lung diseases (ILD), of which the most well-known is idiopathic pulmonary fibrosis (IPF), are a heterogeneous group of diseases, with similar, inflammatory and/or fibrosing mechanisms, which lead to the rapid decline of lung function and implicitly to a high degree of morbidity and mortality. Besides IPF, other interstitial lung diseases, such as those associated with connective tissue diseases, the most common being rheumatoid arthritis and systemic sclerosis, can develop a progressive fibrosing phenotype. Thus, because they have similar pathogenic mechanisms and clinical manifestations, all these diseases are described under the term of progressive fibrosing interstitial lung disease (PF-ILD). It is recommended that the diagnosis, clinical and paraclinical evaluation of ILD be made through a standardized management, within a multidisciplinary team that must include a pulmonologist, radiologist and rheumatologist, evaluation after which the subsequent treatment will be decided. Early diagnosis leads to an effective therapeutic intervention and decreased mortality. The progressive character has been defined if the progression occurs despite the current optimal management and treatment, which includes glucocorticoids and immunosuppressive therapy, at which point the indication of the antifibrotic treatment appears. The complete evaluation of ILD involves a rigorous anamnesis and clinical examination to identify environmental and professional risk factors, the patient’s chronic medication, family and personal history, the onset of the disease, as well as the identification by auscultation of bilateral basal crackles. From the paraclinical examination, the most important is the imaging studies (standard chest X-rays and mandatory HR-CT) which provide information about the anatomy, pattern, evolution in time or clues related to the underlying disease. The progressive character has been defined if the progression occurs despite the current optimal management and treatment, which includes glucocorticoids and immunosuppressive therapy, at which point the indication of the antifibrotic treatment appears. Evaluation of lung function is very important to complete the patient picture with PF-ILD, and the gold standard is the combination of spirometry, body plethysmography with diffusing capacity for carbon monoxide (DLCO), gasometry and an exercise test. Using this information, the optimal treatment will be led by the same multidisciplinary team that established the diagnosis, taking into account many aspects related to the characteristics of the disease, the cause, the safety profile and it will be monitored according to the existing protocols.

Epidemiology and real-life experience in progressive pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF), characterized by relentless disease progression from the time of diagnosis, is part of a larger group of chronic fibrosing interstitial lung diseases (ILDs). A proportion of patients with non-IPF ILDs may develop, despite conventional treatment, a progressive pulmonary fibrosis (PPF), also referred to as ILD with a progressive fibrosing phenotype (PF-ILD). These patients experience worsening of respiratory symptoms, decline in lung function, and early mortality. The goal of this review is to describe the epidemiology and recent real-life cohorts of PF-ILD, with implications for management. The relatively new concept of PF-ILD has aroused active clinical research over the past years. To understand risk factors for progression and the real burden of the disease is crucial to improve management. In the last 2 years, different cohort studies have addressed these questions. They showed that almost one-third of the non-IPF fibrotic ILD patients develop PF-ILD or PPF. Emerging data show similarities in prognosis between patients with IPF or with non-IPF PF-ILD patients. Early detection and appropriate treatment of this group of patients is a priority. Further research is needed to identify risk factors of progression, to clarify the assessment of progression in clinical practice, for a better management of patients with PF-ILD in a real-world setting.

Chronic fibrosing interstitial lung diseases according to the register of Irkutsk (Russia)

The Interstitial lung diseases (ILD) are a wide heterogeneous group of disorders, different in many parameters, however having similar pathophysiological mechanisms. Idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia (NSIP), chronic hypersensitivity pneumonitis (CHP), ILD associated with autoimmune disorders (predominantly systemic sclerosis (SSc ILD) and rheumatoid arthritis (RA ILD), and other diseases may be accompanied by the formation of pulmonary fibrosis. Currently there are no generally accepted criteria for the fibrosing and progressive fibrosing ILD, and the information on the frequency of these conditions is limited.The study aims to research the structure of fibrosing ILD and the frequency of the progressive fibrosing phenotype (PFP) according to the register of patients with ILD in Irkutsk, Russia.Methods. At the first stage information letters were sent to all medical institutions of Irkutsk with recommendations on all referral patients with ILD for further examination. At the second stage, each ILD case was verified collegially (n = 270). All patients’ data were analysed in terms of clinical, functional, radiological and histological aspects. A register of ILD patients was formed based on this analysis. The follow-up period was 1 to 5 years.Results. According to the results of a comprehensive assessment, HRCT signs of pulmonary fibrosis were detected by 104 patients (38.5%). fibrosing course was observed in 100% IPF and SSc ILD, in 90.9% of CHP, 71.4% of NSIP and 60% of RA ILD. 61 patients (22.6% of all ILD cases, 58.6% of fibrosing ILD) was diagnosed with PFP. The 5-year mortality for PFP ILD was 55.5%.Conclusion. In the case of a PFP development, the evolution of ILD loses its nosological specificity, acquiring similarity with IPF. Due to the high mortality rate, it is necessary to actively identify the progressive fibrosing course of a wide range of ILD and to prescribe an antifibrotic therapy in a timely manner.

Antifibrotics effects of nintedanib on lung fibroblasts derived from patients with progressive fibrosing intertitial lung diseases

A larger group of patients with differing clinical interstitial lung diseases (ILD) develop a progressive fibrosing (PF-ILD) phenotype during the course of their disease despite immunosuppressive therapy. The kinase inhibitor nintedanib is approved for the treatment of the most agressive fibrosing ILD, idiopathic pulmonary fibrosis (IPF), and was recently reported to exert positives effects on patients with PF-ILD. In order to highlight the in vitro anti-fibrotic properties of nintedanib in non-IFP PF-ILD, we investigated its effects on main functions of human lung fibroblasts (HLFs) isolated from patients with progressive-fibrosing phenotype like chronic fibrotic hypersensitivity pneumonitis, sarcoidosis, idiopathic nonspecific interstitial pneumonia and unclassifiable ILD. PF-ILD HLFs were pre-treated with nintedanib (0.01–1 μM) and stimulated with PDGF-BB (25–50 ng/ml) or TGF-β1 (1 ng/ml). PDGF receptor and ERK activation, proliferation, migration and differentiation of cells were assessed. Nintedanib in a range of 0.01 to 1 μM strongly blocked the phosphorylation of PDGF receptor and decreased ERK1/2 phosphorylation induced by PDGF-BB. The pro-proliferative and pro-migratory phenotype driven by PDGF-BB were also significantly reduced by nintedanib from 0.03 μM without affected the cell viability. Moreover, the drug also decreased, in a concentration dependant manner, TGF-β1-induced myofibroblastic differentiation by down-regulating mRNA and protein expression level of collagen, fibronectin, α-Smooth muscle actin and the phosphorylation of SMAD2/3 signalling pathway. Our data demonstrates that nintedanib, as described in IPF, counteracts the detrimental functions of PF-ILD fibroblasts and are in favor of the management of PF-ILD with this drug.

Progressive fibrosing interstitial lung disease: prevalence and clinical outcome

BackgroundThe progressive fibrosing (PF) phenotype of interstitial lung disease (ILD) is characterised by worsening respiratory symptoms, lung function, and extent of fibrosis on high-resolution computed tomography. We aimed to investigate the prevalence and clinical outcomes of PF-ILD in a real-world cohort and assess the prognostic significance of the PF-ILD diagnostic criteria.MethodsClinical data of patients with fibrosing ILD other than idiopathic pulmonary fibrosis (IPF) consecutively diagnosed at a single centre were retrospectively reviewed. A PF phenotype was defined based on the criteria used in the INBUILD trial.ResultsThe median follow-up duration was 62.7 months. Of the total of 396 patients, the mean age was 58.1 years, 39.9% were men, and rheumatoid arthritis-ILD was the most common (42.4%). A PF phenotype was identified in 135 patients (34.1%). The PF-ILD group showed lower forced vital capacity and total lung capacity (TLC) than the non-PF-ILD group. The PF-ILD group also showed poorer survival (median survival, 91.2 months vs. not reached; P < 0.001) than the non-PF-ILD group. In multivariable Cox analysis adjusted for age, DLCO, HRCT pattern, and specific diagnosis, PF phenotype was independent prognostic factor (hazard ratio, 3.053; P < 0.001) in patients with fibrosing ILD. Each criterion of PF-ILD showed similar survival outcomes.ConclusionsOur results showed that approximately 34% of patients with non-IPF fibrosing ILD showed a progressive phenotype and a poor outcome similar to that of IPF, regardless of the diagnostic criteria used.

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.

Chronic fibrosing progressing interstitial lung disease: a decision of Multidisciplinary Expert Board

Introduction. The natural course of some interstitial lung diseases (ILD) is characterized by progressive fibrosing phenotype resembling idiopathic pulmonary fibrosis (IPF). Until recently, the antifibrotic drug nintedanib was approved for treatment of the only fibrosing ILD which was IPF. A new indication for this drug which has been registered in Russian Federation in 2021 includes other fibrosing ILDs with progressive phenotype (PF-ILDs) and ILD associated with systemic scleroderma (SS-ILD).The aim of this publication is to describe general considerations of the decision of Multidisciplinary Expert Board on diagnosis and treatment of PF-ILDs including SS-ILD.Results. According to the extension in nintedanib use mentioned above, the Expert Board created an algorithm for diagnosis and treatment of patients with PF-ILDs and criteria for nuntedanib administration in PF-ILDs.Conclusion. Antifibrotic therapy is needed for patients with PF-ILDs with the failure of the stanrard therapy. In those patients antifibrotic treatment should be initiated as early as possible to better preserve the lung function.

Harnessing the Role of HDAC6 in Idiopathic Pulmonary Fibrosis: Design, Synthesis, Structural Analysis, and Biological Evaluation of Potent Inhibitors.

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by a progressive-fibrosing phenotype. IPF has been associated with aberrant HDAC activities confirmed by our immunohistochemistry studies on HDAC6 overexpression in IPF lung tissues. We herein developed a series of novel hHDAC6 inhibitors, having low inhibitory potency over hHDAC1 and hHDAC8, as potential pharmacological tools for IPF treatment. Their inhibitory potency was combined with low in vitro and in vivo toxicity. Structural analysis of 6h and structure-activity relationship studies contributed to the optimization of the binding mode of the new molecules. The best-performing analogues were tested for their efficacy in inhibiting fibrotic sphere formation and cell viability, proving their capability in reverting the IPF phenotype. The efficacy of analogue 6h was also determined in a validated human lung model of TGF-β1-dependent fibrogenesis. The results highlighted in this manuscript may pave the way for the identification of first-in-class molecules for the treatment of IPF.