Experimental autotaxin inhibitors for the treatment of idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic Pulmonary Fibrosis (IPF) is a progressive, irreversible, and fatal lung disease with unmet medical needs. Autotaxin (ATX) is an extracellular enzyme involved in the generation of lysophosphatidic acid (LPA). Preclinical and clinical data have suggested the ATX-LPAR signaling axis plays an important role in the pathogenesis and the progression of IPF.

AREAS COVERED

The aim of this review is to provide an update on the available evidence on autotaxin inhibitors in IPF and further details on the ongoing clinical studies involving these molecules.

EXPERT OPINION

The development of autotaxin inhibitors as a potential therapy for idiopathic pulmonary fibrosis has gained attention due to evidence of their involvement in the disease. Preclinical and early-phase clinical studies have explored these inhibitors' efficacy and safety, offering a novel approach in treating this disease. Combining autotaxin inhibitors with existing anti-fibrotic agents is considered for enhanced therapeutic effects. Large phase III trials assessed Ziritaxestat but yielded disappointing results, highlighting the importance of long-term observation and clinical outcomes in clinical research. Patient stratification and personalized medicine are crucial, as pulmonary fibrosis is a heterogeneous disease. Ongoing research and collaboration are essential for this advancement.

An update on emerging drugs for the treatment of idiopathic pulmonary fibrosis: a look towards 2023 and beyond

INTRODUCTION

Currently approved drug treatments for idiopathic pulmonary fibrosis (IPF), pirfenidone and nintedanib, have been shown to slow lung function decline and improve clinical outcomes. Since significant advances in the understanding of pathogenetic mechanisms in IPF, novel potential agents are being tested to identify new targeted and better tolerated therapeutic strategies.

AREAS COVERED

This review describes the evidence from IPF phase II and III clinical trials that have been completed or are ongoing in recent years. The literature search was performed using Medline and Clinicaltrials.org databases. Particular attention is paid to the new inhibitor of phosphodiesterase 4B (BI 1015550), being studied in a more advanced research phase. Some emerging critical issues of the pharmacological research are highlighted considering the recent outstanding failures of several phase III trials.

EXPERT OPINION

An exponential number of randomized clinical trials are underway testing promising new molecules to increase treatment choices for patients with IPF and improve patients' quality of life. The next goals should aim at a deeper understanding of the pathogenic pathways of the disease with the challenging goal of being able not only to stabilize but also to reverse the ongoing fibrotic process in patients with IPF.

GATA1-defective immune-megakaryocytes as possible drivers of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disorder with limited therapeutic options. Insufficient understanding of driver mutations and poor fidelity of currently available animal models has limited the development of effective therapies. Since GATA1 deficient megakaryocytes sustain myelofibrosis, we hypothesized that they may also induce fibrosis in lungs. We discovered that lungs from IPF patients and Gata1low mice contain numerous GATA1negative immune-poised megakaryocytes that, in mice, have defective RNA-seq profiling and increased TGF-β1, CXCL1 and P-selectin content. With age, Gata1low mice develop fibrosis in lungs. Development of lung fibrosis in this model is prevented by P-selectin deletion and rescued by P-selectin, TGF-β1 or CXCL1 inhibition. Mechanistically, P-selectin inhibition decreases TGF-β1 and CXCL1 content and increases GATA1positive megakaryocytes while TGF-β1 or CXCL1 inhibition decreased CXCL1 only. In conclusion, Gata1low mice are a novel genetic-driven model for IPF and provide a link between abnormal immune-megakaryocytes and lung fibrosis.

An up-to-date review of approved and emerging antibody therapies for idiopathic pulmonary fibrosis

INTRODUCTION

The use of pirfenidone and nintedanib in treating Idiopathic Pulmonary Fibrosis (IPF) has shown significant slowing down of the progressive functional decline in these patients. In recent times, antibody-based therapies with precise molecular targets have also been explored as alternative treatments to IPF.

AREAS COVERED

This review aims to summarize the available updates regarding monoclonal antibodies that have been tested in IPF. The drugs describedare developed to antagonize inflammation,immunity pathways and fibrogenesis. Currently, the anti-CTGF pamrevlumab has demonstrated a significant reduction in functional decline as compared to placebo and is undergoing the last stages of phase 3 trial.

EXPERT OPINION

Although antibody-based therapies for IPF have had unsatisfactory results in most trials in the last few years, the pursuit of therapeutic development in this field should continue to deliver a more personalized treatment approach in the future, which is currently not available with existing treatment options. However, several molecules are still under study and some have shown encouraging results in the early phases of clinical trials. Future investigations need to be more carefully designed and valid predictive markers of response to treatment should be used to enhance the effectiveness of future trials.

Challenges in the diagnosis of idiopathic pulmonary fibrosis: the importance of a multidisciplinary approach

INTRODUCTION

The diagnosis of Idiopathic pulmonary fibrosis (IPF) requires the careful exclusion of secondary causes of interstitial lung disease (ILD), and the collaboration among different specialists is considered paramount to establish a diagnosis with high diagnostic confidence. The multidisciplinary discussion (MDD) has assumed an increasing importance over the years in the different phases of the IPF diagnostic work-up.

AREAS COVERED

The role of MDD in the diagnosis and management of IPF will be described. Practical insights will be provided into how and when to perform MDD based on the available scientific evidence. Current limitations and future perspectives will be discussed.

EXPERT OPINION

In the absence of high diagnostic confidence, agreement between different specialists during MDD is recognized as a surrogate indicator of diagnostic accuracy. Often, despite a lengthy evaluation, the diagnosis remains unclassifiable in a significant percentage of patients. MDD therefore appears to be pivotal in attaining an accurate diagnosis of ILDs. The discussion among different specialists can also include other specialists, such as rheumatologists and thoracic surgeons, in addition to the core group of pulmonologists, radiologists, and pathologists. Such discussions can allow greater diagnostic accuracy and have important effects on management, pharmacologic therapies, and prognosis.

Monitoring small airway dysfunction in connective tissue disease-related interstitial lung disease: a retrospective and prospective study

BACKGROUND

Small airway dysfunction (SAD), a hallmark of early lung function abnormality, is a major component of several chronic respiratory disorders. The role of SAD in patients with connective tissue disease-related interstitial lung disease (CTD-ILD) has not been explored.

METHODS

We conducted a two-parts (retrospective and prospective) study to collect pulmonary function tests from CTD-ILD patients. SAD was defined as at least two of the three measures (MMEF, FEF 50%, and FEF 75%) must be 65% of predicted values. Spearman correlation coefficient was used to evaluate association between SAD and other pulmonary function parameters. Mixed effects regression modeling analysis was used to assess response to treatment.

RESULTS

CTD-ILD patients with SAD and without SAD were compared in this study. In the retrospective study, pulmonary function tests (PFTs) from 491 CTD-ILD patients were evaluated, SAD were identified in 233 (47.5%). CTD-ILD patients with SAD were less smokers (17.6% vs. 27.9%, p = 0.007) and more females (74.3% vs. 64.0%, p = 0.015) than those without SAD. CTD-ILD patients with SAD had lower vital capacity (% predicted FVC, 70.4 ± 18.3 vs. 80.0 ± 20.9, p < 0.001) and lower diffusion capacity (% predicted DLCO, 58.8 ± 19.7 vs. 63.8 ± 22.1, p = 0.011) than those without SAD. Among 87 CTD-ILD patients prospectively enrolled, significant improvement in % predicted FVC was observed at 12-months follow-up (6.37 ± 1.53, p < 0.001 in patients with SAD; 5.13 ± 1.53, p = 0.002 in patients without SAD), but not in diffusion capacity and SAD parameters.

CONCLUSION

In our cohort, about half of CTD-ILD patients have SAD, which is less frequent in smokers and more common in female patients. CTD-ILD patients with SAD have worse pulmonary function compared to those without SAD. Improvement of FVC but no improvement of SAD was observed in CTD-ILD patients after treatment.

BI 1015550: an investigational phosphodiesterase 4B (PDE4B) inhibitor for lung function decline in idiopathic pulmonary fibrosis (IPF)

INTRODUCTION

The two available therapies for idiopathic pulmonary fibrosis (IPF), pirfenidone and nintedanib, slow down but do not halt IPF progression. Therefore, several agents with specific molecular targets have been recently investigated to find a cure for IPF. Phosphodiesterase 4 (PDE4) inhibition is known for its anti-inflammatory and antifibrotic properties. BI 1015550, an oral preferential inhibitor of the isoform PDE4B, could express complementary activity to current therapies in IPF and other forms of progressive pulmonary fibrosis.

AREAS COVERED

In this review, we first provide an overview toof the current IPF treatment market, followed by the description of pharmacokinetics and pharmacodynamics of BI 1015550. The main preclinical and early clinical evidence on BI 1015550 is then described, as well as its potential as an IPF treatment.

EXPERT OPINION

Oral treatment with BI 1015550 was shown to stabilize lung function as compared to placebo over 12 weeks, both among patients with and without background antifibrotic use, with an acceptable safety profile in a phase 2 trial, and a phase 3 trial has been initiated. To date, this represents to date the largest effect size for an IPF investigational drug tested in a phase 2 trial with the shortest duration.

Road Toward a New Model of Care for Idiopathic Pulmonary Fibrosis in the Lazio Region

A timely, confirmed diagnosis of Idiopathic Pulmonary Fibrosis (IPF) has a significant impact on the evolution of the disease. The current model of care in the Lazio region (in Italy) was assessed on the basis of real-world data provided by the four reference centers responsible for diagnosing and treating IPF. The 5-year, population-based, retrospective longitudinal study provided the data that is at the basis of the current proposal for a new clinical and therapeutic pathway (DTCP) and has been shared with regional decision makers. A DTCP must be defined and based on four pillars: GPs, pulmonologists, IPF centers, and telemedicine. Each must play a role within a sort of hub-and-spoke model. IPF centers remain the hubs, while spokes are identified in trained GPs and pulmonologists.

Advances with pharmacotherapy for the treatment of interstitial lung disease

INTRODUCTION

In recent decades, the primary focus of pharmaceutical research in interstitial lung diseases (ILD) has been on idiopathic pulmonary fibrosis (IPF). Recently, pharmaceutical development has also focused on other forms of ILDs, including connective tissue diseases associated ILD, fibrotic hypersensitivity pneumonitis, and sarcoidosis.

AREAS COVERED

The authors summarize the advances in pharmacotherapy for the treatment of ILD. Specifically, the authors review the most recent studies and discuss the most recent research findings and future prospects.

EXPERT OPINION

Data collected over the past years have confirmed the efficacy of antifibrotic drugs on slowing disease progression in IPF. The usual strategy for CTD-ILD management is represented by the combined use of corticosteroids and immunosuppressive agents. There is an urgent need for new target therapies. The concept of progressive fibrosing ILD has emerged in the ILD community in recent years, which has led to grouping several diseases with a common disease behavior to find an effective treatment . At present, selecting the best therapy in ILDs should be reasonably performed on a case-by-case basis through a multidisciplinary team discussion in tertiary ILD centers, taking into consideration patients' symptoms, lung functional trends, and radiological changes.

COVID-related fibrosis: insights into potential drug targets

INTRODUCTION

Lung injury in severe COVID-19 pneumonia can rapidly evolve to established pulmonary fibrosis, with prognostic implications in the acute phase of the disease and long-lasting impact on the quality of life of COVID-19 survivors. This is an emerging medical need, and it has been hypothesized that antifibrotic treatments could have a role in ameliorating the fibrotic process in the lungs of these patients.

AREAS COVERED

The safety and efficacy of available antifibrotic drugs (nintedanib and pirfenidone) and novel promising agents are being assessed in several ongoing clinical trials that were performed either in critically ill patients admitted to intensive care, or in discharged patients presenting fibrotic sequalae from COVID-19. Literature search was performed using Medline and Clinicaltrials.org databases (2001-2021).

EXPERT OPINION

Despite the strong rationale support the use of antifibrotic therapies in COVID-related fibrosis, there are several uncertainties regarding the timing for their introduction and the real risks/benefits ratio of antifibrotic treatment in the acute and the chronic phases of the disease. The findings of ongoing clinical trials and the long-term observation of longitudinal cohorts will eventually clarify the best management approach for these patients.

Adjunctive corticosteroid treatment for organizing pneumonia in COVID-19 patients with persistent respiratory failure

Since the beginning of COVID-19 pandemic, clinical, radiological and histopathological features consistent with viral-induced organizing pneumonia (OP) have been reported as hallmark characteristics of the disease. Here, we describe the case of ten patients with severe COVID-19 pneumonia treated with methylprednisolone 1mg/kg for showing clinical and radiological features suggestive of OP at least 20 days after symptom onset and despite standard treatment for COVID-19.

Residual respiratory impairment after COVID-19 pneumonia

INTRODUCTION

The novel coronavirus SARS-Cov-2 can infect the respiratory tract causing a spectrum of disease varying from mild to fatal pneumonia, and known as COVID-19. Ongoing clinical research is assessing the potential for long-term respiratory sequelae in these patients. We assessed the respiratory function in a cohort of patients after recovering from SARS-Cov-2 infection, stratified according to PaO2/FiO2 (p/F) values.

METHOD

Approximately one month after hospital discharge, 86 COVID-19 patients underwent physical examination, arterial blood gas (ABG) analysis, pulmonary function tests (PFTs), and six-minute walk test (6MWT). Patients were also asked to quantify the severity of dyspnoea and cough before, during, and after hospitalization using a visual analogic scale (VAS). Seventy-six subjects with ABG during hospitalization were stratified in three groups according to their worst p/F values: above 300 (n = 38), between 200 and 300 (n = 30) and below 200 (n = 20).

RESULTS

On PFTs, lung volumes were overall preserved yet, mean percent predicted residual volume was slightly reduced (74.8 ± 18.1%). Percent predicted diffusing capacity for carbon monoxide (DLCO) was also mildly reduced (77.2 ± 16.5%). Patients reported residual breathlessness at the time of the visit (VAS 19.8, p < 0.001). Patients with p/F below 200 during hospitalization had lower percent predicted forced vital capacity (p = 0.005), lower percent predicted total lung capacity (p = 0.012), lower DLCO (p < 0.001) and shorter 6MWT distance (p = 0.004) than patients with higher p/F.

CONCLUSION

Approximately one month after hospital discharge, patients with COVID-19 can have residual respiratory impairment, including lower exercise tolerance. The extent of this impairment seems to correlate with the severity of respiratory failure during hospitalization.

Emerging drugs for the treatment of idiopathic pulmonary fibrosis: 2020 phase II clinical trials

INTRODUCTION

The enthusiasm generated by the approval of pirfenidone and nintedanib as the first effective therapies for IPF led the IPF scientific community to investigate an increasing number of novel agents in well-designed randomized controlled trials, in the hope to find a cure for these patients.

AREAS COVERED

This reviews the evidence from IPF phase II trials that were completed or started in 2020. Literature search was performed using Medline and Clinicaltrials.org databases.

EXPERT OPINION

Randomized clinical trials revolutionized the management of IPF, leading to the discovery of the first therapies capable of slowing down functional deterioration in these patients. The recently published findings of the first successful phase II trials since pirfenidone and nintedanib will hopefully inaugurate a new era in the therapeutic scenario of IPF, where consolidated treatments of proven efficacy and novel targeted agents contribute together to reach the final goal of halting the fibrotic process of this dreadful disease.

An updated safety review of the drug treatments for idiopathic pulmonary fibrosis

INTRODUCTION

The approval of antifibrotic agents nintedanib and pirfenidone revolutionized the management of idiopathic pulmonary fibrosis (IPF). These treatments showed acceptable tolerability in randomized-clinical trials; however, they have been associated with a spectrum of potential side effects which require careful assessment of risks and benefits in the individual patient before commencing and during antifibrotic therapy.

AREAS COVERED

The accrued evidence on safety of nintedanib and pirfenidone is summarized, from the first randomized clinical trials to the open-label extension studies and post-marketing clinical experiences which helped clarify the long-term tolerability of these drugs.

EXPERT OPINION

The data collected over the last years confirmed the comparable tolerability profile of nintedanib and pirfenidone. The physician's assessment of expected side effects may help decide the optimal first-line therapy for the individual patient. Patient's counseling during treatment remains essential to manage emerging adverse events and eventually inform the decision of drug discontinuation.

Role of Stenotrophomonas maltophilia isolation in patients with non-CF bronchiectasis

INTRODUCTION

Stenotrophomonas maltophilia is a bacteria whose role in patients with cystic fibrosis (CF) bronchiectasis has been previously studied; little is known about its role in non-CF bronchiectasis.

MATERIALS AND METHODS

Aim of our study is to investigate the risk factors for S. maltophilia acquisition and its clinical impact on bronchiectasis patients. A retrospective observational cohort study enrolling patients attending the Bronchiectasis Clinic at the Royal Infirmary of Edinburgh, Scotland, UK. A total of 167 bronchiectasis patients undergoing intravenous (IV) antibiotic therapy were selected and divided according to single or chronic S. maltophilia isolation in sputum. The risk factors and prognostic impact were studied.

RESULTS

Single isolation was independently associated with lower baseline % predicted forced expiratory volume in 1 s [odds ratio (OR) 0.98; 95% confidence interval (CI) 0.970-1.044; P = 0.025] and with less radiological involvement (OR 0.379; 95% CI 0.175-0.819; P = 0.01). Chronic isolation was associated with the number of IV antibiotic courses in the year before and after the first isolation (OR 1.2; 95% CI 1.053-1.398; P = 0.007) and with the absence of Pseudomonas aeruginosa colonization (OR 0.207; 95% CI 0.056-0.764; P = 0.02). In the chronic isolation group, there were more exacerbations and more need of IV antibiotics in the year after the first isolation.

CONCLUSIONS

Poor lung function is the main independent risk factor for single isolation of S. maltophilia. For chronic colonization, the main independent risk factor is the number of IV antibiotic courses and the absence of P. aeruginosa chronic colonization. Only when chronically present, S. maltophilia had a clinical impact with more exacerbations.

Mediastinal lymph node enlargement in idiopathic pulmonary fibrosis: relationships with disease progression and pulmonary function trends

BACKGROUND AND OBJECTIVES

Evidence of mediastinal Lymph Node Enlargement (LNE) on CT scan is a common finding in idiopathic pulmonary fibrosis (IPF). We sought to investigate whether the involvement of mediastinal lymph nodes is associated with accelerated disease progression, and explored the changes occurring in mediastinal lymph nodes during the radiological follow up of these patients.

METHODS

This retrospective study included IPF patients referred to a single ILD centre in Italy. A consensus-based assessment of mediastinal LNE on chest CT scan was performed by two thoracic radiologists. Kaplan-Meier curves and multivariate Cox proportional hazards regression were used to assess hazard ratios for mortality and disease progression (defined as categorical FVC decline ≥10%). The annualized rates of change in functional parameters for each patient were calculated using mixed linear models.

RESULTS

The study population consisted of 152 IPF patients, of whom 135 (89%) received antifibrotic treatment for IPF during the study follow up. Patients having evidence of 3 or more enlarged mediastinal lymph nodes on baseline CT scan showed increased rates of mortality (HR 5.03, 95% CI 1.86-13.62, p ≤ 0.001) and significant disease progression (HR 2.99, 95% CI 1.22-7.33, p = 0.17) as compared to patients without LNE, after adjusting for GAP stage. Among 62 patients with LNE who underwent a follow up CT scan of the chest and received antifibrotic treatment, 57 (92%) maintained evidence mediastinal LNE over time.

CONCLUSIONS

Diffuse mediastinal lymph node involvement predicts clinically meaningful functional deterioration in patients with IPF.

Restless legs syndrome: A new comorbidity in idiopathic pulmonary fibrosis

OBJECTIVE

Sleep disorders have a high prevalence among patients with idiopathic pulmonary fibrosis (IPF). The prevalence of restless legs syndrome (RLS) is not known in these patients, neither is its clinical impact as a comorbidity. We investigated the association of RLS with IPF and characterized the clinical features of RLS in a cohort of IPF patients.

METHODS

Fifty patients with diagnosis of IPF were prospectively enrolled. RLS was diagnosed using the validated 5-item RLS criteria. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index. The prevalence of RLS in the IPF group was compared to that observed in a group of 293 patients referred for suspect of sleep disorders. The relationships between RLS and clinical parameters were determined using multivariate logistic regression.

RESULTS

Prevalence of RLS in the IPF group was significantly higher than in the control population of patients referred for sleep disorders (IPF: 24%, controls 10%: χ² 6.49, p = 0.011). Higher PSQI score confirmed to be associated with RLS after adjusting for demographics and clinical parameters of disease severity (OR = 1.38, 95%CI 1.08-1.76; p = 0.01).

CONCLUSIONS

RLS is highly prevalent in IPF and significantly worsen sleep quality in these patients. The benefit/risk ratio of a specific therapeutic intervention for RLS in IPF should be assessed in further prospective research.

Pamrevlumab for the treatment of idiopathic pulmonary fibrosis

INTRODUCTION

The two available therapies for idiopathic pulmonary fibrosis (IPF), pirfenidone and nintedanib, slow down but do not halt IPF progression. As such, in the last few years several agents with specific molecular targets have been investigated to find a cure forIPF. Pamrevlumab, a recombinant human antibody that binds to connective tissue growth factor (CTGF) has emerged as a potential therapy for IPF and has advanced to phase 3 clinical trials.

AREAS COVERED

The authors offer a backdrop to the current IPF treatment market and describe the chemistry, pharmacokinetics and pharmacodynamics of pamrevlumab. They summarize the preclinical and early clinical evidence on pamrevlumab and propose ways of progressing this agent further as a potential IPF treatment.

EXPERT OPINION

Pamrevlumab was effective and safe in patients in a placebo-controlled phase 2 trial, demonstrating its potential to become an alternative therapeutic option for IPF; however, the feasibility of intravenous administration in clinical practice may be a hurdle to its use as a first-line treatment. Further studies are necessary to assess its effects when administered with pirfenidone or nintedanib and this could open up a new era of combined therapeutic approaches for IPF.

Fibrotic Hypersensitivity Pneumonitis: Diagnosis and Management

Fibrotic hypersensitivity pneumonitis is a complex interstitial lung disease that is not entirely understood. In its chronic and fibrotic form, hypersensitivity pneumonitis is one of the main mimickers of idiopathic pulmonary fibrosis (IPF). Distinguishing between these two conditions is challenging but is of particular clinical relevance. Two approved therapies are available for IPF, and a considerable number of clinical trials are now exploring newer pharmacological options. This impressive research effort is a consequence of new pathogenetic understanding, updated diagnostic criteria and a long history of pharmacological trials. Conversely, current knowledge gaps on pathogenesis of chronic hypersensitivity pneumonitis, coupled with lack of validated diagnostic criteria, make the management of this disease an unsolved clinical challenge. This also reflects the paucity of therapeutic clinical trials in this field. In this review, we describe the current evidence and the possible future options to approach this complex disease.

Antibody-based therapies for idiopathic pulmonary fibrosis

INTRODUCTION

Pirfenidone and nintedanib have been the first agents demonstrating to slow down the progressive functional decline in patients with Idiopathic Pulmonary Fibrosis (IPF). Antibody-based therapies with precise molecular targets have been largely investigated over the last decade in IPF as alternative or complementary treatments, in the hope to ameliorate the relentless fibrotic process of IPF.

AREAS COVERED

In this review, we summarize the available evidence on two groups of monoclonal antibodies tested in IPF: those directed against known fibrogenic factors and matrix components, and those developed to antagonize the inflammation and immunity pathways. While the latter have failed to demonstrate any clinical efficacy in IPF so far, the anti-CTGF pamrevlumab has been recently proved to be capable of slowing down functional decline as compared to placebo, prompting further investigation.

EXPERT OPINION

Despite most trials on antibody-based therapies in IPF provided so far unsatisfying results, the therapeutic development in this field should continue to be pursued to deliver a more personalized treatment approach in the future, which is not currently offered by available treatment options. A more careful trial designing and the use of valid predictive markers of response to treatment are required to enhance effectiveness of future trials.

X-ray Micro-Computed Tomography for Nondestructive Three-Dimensional (3D) X-ray Histology

Historically, micro-computed tomography (μCT) has been considered unsuitable for histologic analysis of unstained formalin-fixed, paraffin-embedded soft tissue biopsy specimens because of a lack of image contrast between the tissue and the paraffin. However, we recently demonstrated that μCT can successfully resolve microstructural detail in routinely prepared tissue specimens. Herein, we illustrate how μCT imaging of standard formalin-fixed, paraffin-embedded biopsy specimens can be seamlessly integrated into conventional histology workflows, enabling nondestructive three-dimensional (3D) X-ray histology, the use and benefits of which we showcase for the exemplar of human lung biopsy specimens. This technology advancement was achieved through manufacturing a first-of-kind μCT scanner for X-ray histology and developing optimized imaging protocols, which do not require any additional sample preparation. 3D X-ray histology allows for nondestructive 3D imaging of tissue microstructure, resolving structural connectivity and heterogeneity of complex tissue networks, such as the vascular network or the respiratory tract. We also demonstrate that 3D X-ray histology can yield consistent and reproducible image quality, enabling quantitative assessment of a tissue's 3D microstructures, which is inaccessible to conventional two-dimensional histology. Being nondestructive, the technique does not interfere with histology workflows, permitting subsequent tissue characterization by means of conventional light microscopy-based histology, immunohistochemistry, and immunofluorescence. 3D X-ray histology can be readily applied to a plethora of archival materials, yielding unprecedented opportunities in diagnosis and research of disease.

"Velcro-type" crackles predict specific radiologic features of fibrotic interstitial lung disease

BACKGROUND

"Velcro-type" crackles on chest auscultation are considered a typical acoustic finding of Fibrotic Interstitial Lung Disease (FILD), however whether they may have a role in the early detection of these disorders has been unknown. This study investigated how "Velcro-type" crackles correlate with the presence of distinct patterns of FILD and individual radiologic features of pulmonary fibrosis on High Resolution Computed Tomography (HRCT).

METHODS

Lung sounds were digitally recorded from subjects immediately prior to undergoing clinically indicated chest HRCT. Audio files were independently assessed by two chest physicians and both full volume and single HRCT sections corresponding to the recording sites were extracted. The relationships between audible "Velcro-type" crackles and radiologic HRCT patterns and individual features of pulmonary fibrosis were investigated using multivariate regression models.

RESULTS

148 subjects were enrolled: bilateral "Velcro-type" crackles predicted the presence of FILD at HRCT (OR 13.46, 95% CI 5.85-30.96, p < 0.001) and most strongly the Usual Interstitial Pneumonia (UIP) pattern (OR 19.8, 95% CI 5.28-74.25, p < 0.001). Extent of isolated reticulation (OR 2.04, 95% CI 1.62-2.57, p < 0.001), honeycombing (OR 1.88, 95% CI 1.24-2.83, < 0.01), ground glass opacities (OR 1.74, 95% CI 1.29-2.32, p < 0.001) and traction bronchiectasis (OR 1.55, 95% CI 1.03-2.32, p < 0.05) were all independently associated with the presence of "Velcro-type" crackles.

CONCLUSIONS

"Velcro-type" crackles predict the presence of FILD and directly correlate with the extent of distinct radiologic features of pulmonary fibrosis. Such evidence provides grounds for further investigation of lung sounds as an early identification tool in FILD.

Idiopathic pulmonary fibrosis: pathogenesis and management

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease characterized by the aberrant accumulation of fibrotic tissue in the lungs parenchyma, associated with significant morbidity and poor prognosis. This review will present the substantial advances achieved in the understanding of IPF pathogenesis and in the therapeutic options that can be offered to patients, and will address the issues regarding diagnosis and management that are still open.

Main body

Over the last two decades much has been clarified about the pathogenic pathways underlying the development and progression of the lung scarring in IPF. Sustained alveolar epithelial micro-injury and activation has been recognised as the trigger of several biological events of disordered repair occurring in genetically susceptible ageing individuals. Despite multidisciplinary team discussion has demonstrated to increase diagnostic accuracy, patients can still remain unclassified when the current diagnostic criteria are strictly applied, requiring the identification of a Usual Interstitial Pattern either on high-resolution computed tomography scan or lung biopsy.

Outstanding achievements have been made in the management of these patients, as nintedanib and pirfenidone consistently proved to reduce the rate of progression of the fibrotic process. However, many uncertainties still lie in the correct use of these drugs, ranging from the initial choice of the drug, the appropriate timing for treatment and the benefit-risk ratio of a combined treatment regimen. Several novel compounds are being developed in the perspective of a more targeted therapeutic approach; in the meantime, the supportive care of these patients and their carers should be appropriately prioritized, and greater efforts should be made toward the prompt identification and management of relevant comorbidities.

Conclusions

Building on the advances in the understanding of IPF pathobiology, the further investigation of the role of gene variants, epigenetic alterations and other molecular biomarkers reflecting disease activity and behaviour will hopefully enable earlier and more confident diagnosis, improve disease phenotyping and support the development of novel agents for personalized treatment of IPF.

Occurrence of idiopathic pulmonary fibrosis during immunosuppressive treatment: a case report

Background

Immunosuppressive therapy has been—until the recent release of new guidelines on diagnosis and management—the recommended treatment for idiopathic pulmonary fibrosis. However, its efficacy in patients with idiopathic pulmonary fibrosis has always been a matter of debate.

Case presentation

We report the occurrence of idiopathic pulmonary fibrosis in a white man receiving chronic immunosuppressive treatment following a heart transplant.

Conclusions

This case report suggests that the immune mechanisms targeted by azathioprine and cyclosporine do not play a role in the pathogenesis of idiopathic pulmonary fibrosis.

Three-dimensional characterization of fibroblast foci in idiopathic pulmonary fibrosis

In idiopathic pulmonary fibrosis (IPF), the fibroblast focus is a key histological feature representing active fibroproliferation. On standard 2D pathologic examination, fibroblast foci are considered small, distinct lesions, although they have been proposed to form a highly interconnected reticulum as the leading edge of a “wave” of fibrosis. Here, we characterized fibroblast focus morphology and interrelationships in 3D using an integrated micro-CT and histological methodology. In 3D, fibroblast foci were morphologically complex structures, with large variations in shape and volume (range, 1.3 × 10⁴ to 9.9 × 10⁷ μm³). Within each tissue sample numerous multiform foci were present, ranging from a minimum of 0.9 per mm³ of lung tissue to a maximum of 11.1 per mm³ of lung tissue. Each focus was an independent structure, and no interconnections were observed. Together, our data indicate that in 3D fibroblast foci form a constellation of heterogeneous structures with large variations in shape and volume, suggesting previously unrecognized plasticity. No evidence of interconnectivity was identified, consistent with the concept that foci represent discrete sites of lung injury and repair.

Integrated histological and microCT analyses reveal that 3D fibroblast foci are discrete structures with marked variations in shape and volume, suggesting previously unrecognized plasticity.

Novel drug targets for idiopathic pulmonary fibrosis

Idiopathic Pulmonary Fibrosis (IPF) is a progressive, fatal lung disorder of unknown cause with a highly variable and unpredictable clinical course. The advances made in deciphering IPF pathobiology over the last decades have led to the approval of two anti-fibrotic molecules, pirfenidone and nintedanib, that showed to be effective in significantly reducing the rate of progression of the disease. Such pharmacological breakthroughs represent a dramatic change in the management of these patients and are reflected in updated international guidelines. However, the need to find a cure for this devastating disease remains unmet and the development of novel therapeutic agents remains hurdled by several factors. Here, we review the latest insights into therapeutic approaches for IPF and the available evidence for the most promising novel compounds currently under development, and discuss the challenges and evolution of IPF clinical research over the next few years.

Levels of circulating endothelial cells are low in idiopathic pulmonary fibrosis and are further reduced by anti-fibrotic treatments

BACKGROUND

It has been suggested that circulating fibrocytes and endothelial cells actively participate in the intense remodelling of the pulmonary vasculature in patients with idiopathic pulmonary fibrosis (IPF). Indeed, fibrotic areas exist that have fewer blood vessels, whereas adjacent non-fibrotic tissue is highly vascularized. The number of circulating endothelial cells (CEC) and endothelial progenitor cells (EPC) might reflect the balance between vascular injury and repair. Thus, fibrocytes as well as endothelial cells could potentially be used as biomarkers of disease progression and treatment outcome.

METHODS

Peripheral blood samples were collected from 67 patients with a multidisciplinary diagnosis of IPF and from 45 age-matched and sex-matched healthy volunteers. Buffy coat was isolated according to standard procedures and at least 20 million cells were stained with different monoclonal antibodies for the detection of CEC, EPC and circulating fibrocytes. For the detection of CEC and EPC, cells were stained with anti-CD45, anti-CD34, anti-CD133, anti-CD14, anti-CD309 and with the viability probe Far-Red LIVE/DEAD. For the detection of circulating fibrocytes, cells were first stained with LIVE/DEAD and the following monoclonal antibodies: anti-CD3, anti-CD19, anti-CD45, anti-CD34 and anti-CD14, then cells were fixed, permeabilized and stained with fluorochrome-conjugated anti-collagen I monoclonal antibodies.

RESULTS

Patients with IPF displayed almost undetectable levels of circulating fibrocytes, low levels of CEC, and normal levels of EPC. Patients treated with nintedanib displayed higher levels of CEC, but lower levels of endothelial cells expressing CD309 (the type II receptor for vascular endothelial growth factor). Treatment with both nintedanib and pirfenidone reduced the percentage of CEC and circulating fibrocytes.

CONCLUSIONS

Levels of CEC were reduced in patients with IPF as compared to healthy individuals. The anti-fibrotic treatments nintedanib and pirfenidone further reduced CEC levels. These findings might help explain the mechanism of action of these drugs and should be explored as predictive biomarkers in IPF.

Mindfulness-based stress reduction in patients with interstitial lung diseases: a pilot, single-centre observational study on safety and efficacy

Background

Chronic, progressive respiratory symptoms are associated with great psychological and emotional impact in patients suffering from interstitial lung disease (ILD). This single-centre pilot study evaluated for the first time the safety, feasibility and efficacy of a Mindfulness Based Stress Reduction Program (MBSR) in a group of patients with ILD.

Methods

Prospective observational study set in a university hospital ILD outpatient clinic. Nineteen patients with different ILDs were recruited 2 months prior to the start of the 8-week MBSR program and followed up for 12 months. Primary outcomes were program safety and feasibility, while secondary outcomes were changes in moods and stress (assessed by Profile Of Mood State (POMS) and Perceived Stress Scale (PSS) questionnaires), symptoms (Shortness Of Breath (SOB) and Cough And Sputum Assessment (CASA-Q) questionnaires), lung function and exercise tolerance at 12 months.

Results

Two patients (10.5%) dropped out in the observational period before the start of the MBSR intervention because of non-respiratory causes. All 17 patients who entered the 8-week MBSR program managed to complete it with an adherence average of eight sessions of nine. No adverse events related to the mindfulness training were reported. Statistically significant improvements in the POMS total score and in several individual items of POMS and PSS were observed throughout the study. However, respiratory questionnaire scores, lung function and exercise tolerance did not show a significant difference over time.

Conclusions

An MBSR program appears to be safe and feasible in patients with ILD, and might affect perceived moods and stress producing a positive and lasting improvement in several stress-related negative domains. These findings pave the way to larger (possibly multicentre), randomised, controlled confirmatory trials.