Presentation, diagnosis and clinical course of the spectrum of progressive-fibrosing interstitial lung diseases

The Impact of Multidisciplinary Discussion (MDD) in the Diagnosis and Management of Fibrotic Interstitial Lung Diseases

Accurate diagnosis of interstitial lung disease (ILD) is crucial for management and prognosis but can be challenging even for experienced clinicians. Expert multidisciplinary discussion (MDD) is considered the reference standard for ILD diagnosis; however, there remain concerns regarding lack of validation studies and relative limited information on the impact of MDD in real-life clinical practice. The goal of this study was to assess the effect of MDD in providing a specific ILD diagnosis, changing the diagnosis provided upon referral, and to determine how often and in which way MDD altered management. Material and Methods. Retrospective observational study in an ILD referral tertiary academic center. MDD diagnoses were categorized as specific, provisional, and unclassifiable ILD. Pre-MDD and MDD diagnoses were compared for change in diagnosis and concordance rates for specific diagnoses. Relevant change in management including initiation or change in pharmacological treatment, referral to surgical biopsy, and nonpharmacological management were recorded. Results. 126 cases were included (79M, 47F, 36–93 years, mean 70 y). Specific MDD diagnosis was provided in 62% (78/126); 12% (15/126) had provisional diagnosis, and 21% (27/126) was unclassifiable. Overall agreement for specific pre-MDD and MDD diagnosis was 41% (52/126) and 80% for idiopathic pulmonary fibrosis (IPF) diagnosis. MDD altered diagnosis in 37% (47/126) and changed management in 39% (50/126). Amongst concordant diagnoses, management was altered in 46% (24/52). In summary, MDD provided a specific diagnosis discordant with pre-MDD diagnosis in a significant proportion of cases and was particularly valuable in the diagnosis of non-IPF ILD. MDD often altered management and had relevant impact on management even in cases with concordant pre-MDD diagnosis.

Fellowship Education in Interstitial Lung Disease. A National Survey of Program Directors and Trainees

Background: Whether graduating pulmonary and critical care medicine (PCCM) fellows feel adequately trained in interstitial lung disease (ILD) remains unknown. In addition, there are no published data describing the current approach to educating trainees about ILD. Objective: To characterize the present state of ILD training during fellowship and to determine graduating PCCM fellows' perceived abilities to diagnose and manage ILD. Methods: We surveyed PCCM fellowship program directors nationwide and compared their perceptions of graduating fellows' abilities to diagnose, provide initial management to, and offer longitudinal care to patients with ILD using a series of unpaired t tests. We also inquired about existing practices for educating fellows about ILD. We then surveyed graduating PCCM fellows from 19 different preselected programs to assess comfort level with ILD in comparison with other core clinical domains. Results: Program director respondents (n = 74, 40% response rate) rated graduating fellows' abilities to establish specific ILD diagnoses and to provide initial management similarly (4.3 ± 0.8 on five-point Likert scale), whereas the ability to provide longitudinal expert care was rated significantly lower (3.8 ± 0.9, P = 0.001). Most respondents (n = 52, 70.3%) reported having dedicated outpatient ILD specialists with whom fellows could rotate, but only half required this rotation. In addition, very few (n = 17, 23.0%) reported that a majority of patients with suspected or newly diagnosed ILD were scheduled in fellow clinics, many of whom received subsequent longitudinal care from dedicated ILD specialists. Among 71 third-year fellow respondents, confidence in managing ILD was rated poorly (3.2 ± 1.0 on a five-point Likert scale) in contrast to more common diseases like chronic obstructive pulmonary disease (4.4 ± 0.7, P < 0.001) and asthma (4.2 ± 0.8, P < 0.001). Conclusion: Trainee exposure to ILD in both clinical and educational settings varied across PCCM fellowships nationwide. Fellows nearing graduation were significantly less confident in their ability to manage ILD compared with other more common pulmonary diseases.

Overlap Syndromes in Sarcoidosis: Clinical Features and Outcomes

Sarcoidosis is a multisystem inflammatory disease characterized by noncaseating granulomatous inflammation. While pulmonary sarcoidosis is most common, extrapulmonary involvement occurs in 50 to 74% of patients and can be the presenting abnormality in some patients. The diagnosis of sarcoidosis is based on a compatible clinical presentation in combination with granulomas on histology and exclusion of other causes. However, the absence of a diagnostic biomarker for sarcoidosis, in addition to the overlap of granulomatous inflammation and nonspecific clinical findings with other diseases, often results in a delayed diagnosis. Sarcoidosis overlap syndromes are typically described when sarcoidosis is diagnosed in the presence of another disease (concurrently or sequentially) with shared clinical and histologic features, or when sarcoidosis presents with clinical features typically observed in, but not diagnostic of, other diseases. Awareness of overlap syndromes is important for clinicians to avoid diagnostic errors and evaluate for concomitant diagnoses that may impact the management and outcome of sarcoidosis. This article is intended to provide an overview of these presentations and the most commonly associated diseases, with attention to their prevalence, clinical features, and reciprocal impacts on disease outcomes.

Clinical and Functional Characteristics of Patients with Unclassifiable Interstitial Lung Disease (uILD): Long-Term Follow-Up Data from European IPF Registry (eurIPFreg)

(1) Aim of the study: In spite of extensive research, up to 20% of interstitial lung diseases (ILD) patients cannot be safely classified. We analyzed clinical features, progression factors, and outcomes of unclassifiable ILD (uILD). (2) Methods: A total of 140 uILD subjects from the University of Giessen and Marburg Lung Center (UGMLC) were recruited between 11/2009 and 01/2019 into the European Registry for idiopathic pulmonary fibrosis (eurIPFreg) and followed until 01/2020. The diagnosis of uILD was applied only when a conclusive diagnosis could not be reached with certainty. (3) Results: In 46.4% of the patients, the uILD diagnosis was due to conflicting clinical, radiological, and pathological data. By applying the diagnostic criteria of usual interstitial pneumonia (UIP) based on computed tomography (CT), published by the Fleischner Society, 22.2% of the patients displayed a typical UIP pattern. We also showed that forced vital capacity (FVC) at baseline (p = 0.008), annual FVC decline ≥10% (p < 0.0001), smoking (p = 0.033), and a diffusing capacity of the lung for carbon monoxide (DLco) ≤55% of predicted value at baseline (p < 0.0001) were significantly associated with progressive disease. (4) Conclusions: The most important prognostic factors in uILD are baseline level and decline in lung function and smoking. The use of Fleischner diagnostic criteria allows further differentiation and accurate diagnosis.

The Burden of Progressive Fibrosing Interstitial Lung Disease: A DELPHI Approach

Introduction

The term progressive fibrosing interstitial lung disease (ILD) describes patients with fibrotic ILDs who, irrespective of the aetiology of the disease, show a progressive course of their disease despite current available (and non-licensed) treatment. Besides in idiopathic pulmonary fibrosis, little is known about management and the burden of patients with fibrotic ILD, particularly those with a progressive behaviour.

Methods

Using the Delphi method, 40 European experts in ILD management delivered information on management of (progressive) fibrosing ILD and on the impact of the disease on patients’ quality of life (QoL) and healthcare resource utilisation (HCRU). Annual costs were calculated for progressive and non-/slow-progressive fibrosing ILD for diagnosis, follow-up management, exacerbation management, and end-of-life care based on the survey data.

Results

Physicians reported that progression in fibrosing ILD worsens QoL in both patients and their caregivers. Progression of fibrosing ILD was associated with a greater use of HCRU for follow-up visits and maintenance treatment compared with the non-/slow progression. The number of patients who suffered at least one acute exacerbation was reported to be more than three times higher in progressive fibrosing ILD patients than in patients with non-/slow-progressive fibrosing ILD. On average, annual estimated costs of progressive fibrosing ILD per patient were 1.8 times higher than those of the non-/slow-progressive form of the disease.

Conclusions

Progression in fibrosing ILD causes a significant impact on QoL and HCRU and costs. These survey data underline the need for safe and effective therapies to slow the disease progression.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01384-0) contains supplementary material, which is available to authorized users.

Advances in Targeted Therapy for Progressive Fibrosing Interstitial Lung Disease

Progressive fibrosing interstitial lung disease (PF-ILD) has been redefined as a new clinical syndrome that shares similar genetics, pathophysiology, and natural history to idiopathic pulmonary fibrosis (IPF). IPF is the most common form of idiopathic interstitial pneumonias, which is progressive in nature and is associated with significant mortality. Therapies targeting an inflammatory and/or immune response have not been consistently effective or well tolerated in patients with IPF. The two antifibrotic drugs approved for IPF treatment, nintedanib and pirfenidone, have been shown to reduce lung function decline in PF-ILD. Novel uses of antifibrotic therapy are emerging due to a paucity of evidence-based treatments for multiple ILD subtypes. In this review, we describe the current body of knowledge on antifibrotic therapy and immunomodulators in PF-ILD, drawing from experience in IPF where appropriate.

The Spectrum of Interstitial Lung Disease Associated with Autoimmune Diseases: Data of a 3.6-Year Prospective Study from a Referral Center of Interstitial Lung Disease and Lung Transplantation

Interstitial lung disease (ILD) may occur in patients with a rheumatic autoimmune disease (AD), increasing their risk of morbidity and mortality. However, little is known about the prevalence of AD in patients diagnosed with an ILD. In this prospective study, we determined the spectrum of ILD associated with AD (AD-ILD) among patients sent for assessment to a single clinic of ILD and lung transplantation from a referral center between May 2016 and December 2019. ILD diagnosis was made by pneumologists based on clinical and radiological findings and pulmonary function test abnormalities. All patients with ILD were also assessed by experienced rheumatologists. During the period of assessment, 338 patients were diagnosed with ILD. Among them, 32.8% fulfilled definitions for an AD. Most cases with AD-ILD had a diagnosis of rheumatoid arthritis (27.0%), systemic sclerosis (26.1%) or anti-synthetase syndrome (17.1%). Interestingly, 18% of the patients with AD-ILD were diagnosed as having an interstitial pneumonia with autoimmune features. Antinuclear antibodies and non-specific interstitial pneumonia were the most frequent positive autoantibodies and radiological pattern found in AD-ILD patients, respectively. In conclusion, our study indicates that a high number of ILD patients have a related AD. Consequently, close collaboration among rheumatologists and pneumologists is needed.

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.

Multi-scale models of lung fibrosis

The architectural complexity of the lung is crucial to its ability to function as an organ of gas exchange; the branching tree structure of the airways transforms the tracheal cross-section of only a few square centimeters to a blood-gas barrier with a surface area of tens of square meters and a thickness on the order of a micron or less. Connective tissue comprised largely of collagen and elastic fibers provides structural integrity for this intricate and delicate system. Homeostatic maintenance of this connective tissue, via a balance between catabolic and anabolic enzyme-driven processes, is crucial to life. Accordingly, when homeostasis is disrupted by the excessive production of connective tissue, lung function deteriorates rapidly with grave consequences leading to chronic lung conditions such as pulmonary fibrosis. Understanding how pulmonary fibrosis develops and alters the link between lung structure and function is crucial for diagnosis, prognosis, and therapy. Further information gained could help elaborate how the healing process breaks down leading to chronic disease. Our understanding of fibrotic disease is greatly aided by the intersection of wet lab studies and mathematical and computational modeling. In the present review we will discuss how multi-scale modeling has facilitated our understanding of pulmonary fibrotic disease as well as identified opportunities that remain open and have produced techniques that can be incorporated into this field by borrowing approaches from multi-scale models of fibrosis beyond the lung.

Diagnostic and Prognostic Biomarkers for Chronic Fibrosing Interstitial Lung Diseases With a Progressive Phenotype

Biomarkers have the potential to become central to the clinical evaluation and monitoring of patients with chronic fibrosing interstitial lung diseases (ILDs) with a progressive phenotype. Here we summarize the current understanding of putative serum, BAL fluid, and genetic biomarkers in this setting, according to their hypothesized pathobiologic mechanisms: evidence of epithelial cell dysfunction (eg, Krebs von den Lungen-6 antigen), fibroblast proliferation and extracellular matrix production or turnover (eg, matrix metalloproteinase-1), or immune dysregulation (eg, CC chemokine ligand 18). While most of the available data come from idiopathic pulmonary fibrosis (IPF), the prototypic progressive fibrosing ILD, data are available in the broader patient population of chronic fibrosing ILDs. A number of these biomarkers show promise, however, none have been validated. In this review article, we assess both the status of proposed biomarkers for chronic fibrosing lung diseases with a progressive phenotype in predicting disease risk or predisposition, diagnosis, prognosis, and treatment response and provide a direct comparison between IPF and other chronic fibrotic ILDs. We also reflect on the current clinical usefulness and future direction of research for biomarkers in the setting of chronic fibrosing ILDs with a progressive phenotype.

Approaching Clinical Trials in Childhood Interstitial Lung Disease and Pediatric Pulmonary Fibrosis

Childhood interstitial lung disease (chILD) comprises a spectrum of rare diffuse lung disorders. chILD is heterogeneous in origin, with different disease manifestations occurring in the context of ongoing lung development. The large number of disorders in chILD, in combination with the rarity of each diagnosis, has hampered scientific and clinical progress within the field. Epidemiologic and natural history data are limited. The prognosis varies depending on the etiology, with some forms progressing to lung transplant or death. There are limited treatment options for patients with chILD. Although U.S. Food and Drug Administration-approved treatments are now available for adult patients with idiopathic pulmonary fibrosis, no clinical trials have been conducted in a pediatric population using agents designed to treat lung fibrosis. This review will focus on progressive chILD disorders and on the urgent need for meaningful objective outcome measures to define, detect, and monitor fibrosis in children.

Pneumocystis jirovecii colonization and its association with pulmonary diseases: a multicenter study based on a modified loop-mediated isothermal amplification assay

Background

Pneumocystis jirovecii (P. jirovecii) is an opportunistic fungal pathogen and the role of its colonization in pulmonary diseases has become a popular focus in recent years. The aim of this study was to develop a modified loop-mediated isothermal amplification (LAMP) assay for detection of Pneumocystis jirovecii (P. jirovecii) DNA amongst non-HIV patients with various pulmonary diseases and use it to examine the prevalence and assess the association of P. jirovecii colonization with clinical characteristics of these diseases.

Methods

We modified the previously reported LAMP assay for P. jirovecii by adding real-time detection. This method was used to detect P. jirovecii colonization in pulmonary samples collected from 403 non-HIV patients with various pulmonary diseases enrolled from 5 hospitals in China. We determined the prevalence of P. jirovecii colonization in 7 types of pulmonary diseases and assessed the association of P. jirovecii colonization with clinical characteristics of these diseases.

Results

The modified LAMP assay showed no cross-reactivity with other common pulmonary microbes and was 1000 times more sensitive than that of conventional PCR. Using the modified LAMP assay, we detected P. jirovecii colonization in 281 (69.7%) of the 403 patients enrolled. P. jirovecii colonization was more common in interstitial lung diseases than in chronic obstructive pulmonary disease (COPD) (84.6% vs 64.5%, P < 0.05). Patients with acute exacerbation of COPD had a higher prevalence of P. jirovecii colonization compared to patients with stabilized COPD (67.4% vs 43.3%, P < 0.05). P. jirovecii colonization was associated with decreased pulmonary function, increased levels of 1,3-β-D-glucan and C-reactive protein, and decreased levels of CD4+ T-cell counts (P < 0.05 for each). Approximately 70% of P. jirovecii colonized patients had confections with other fungi or bacteria.

Conclusions

We developed a modified LAMP assay for detecting P. jirovecii. Our multi-center study of 403 patients supports that P. jirovecii colonization is a risk factor for the development of pulmonary diseases and highlights the need to further study the pathogenesis and transmission of P. jirovecii colonization in pulmonary diseases.

Current Diagnosis and Management of Hypersensitivity Pneumonitis

Hypersensitivity Pneumonitis (HP) one of the most common interstitial lung diseases (ILDs) is characterized by exposure to an inhaled inciting antigen that leads to a host immunologic reaction determining interstitial inflammation and architectural distortion. The underlying pathogenetic mechanisms are unclear. The absence of international shared diagnostic guidelines and the lack of a "gold-standard" test for HP combined with the presence of several clinical and radiologic overlapping features makes it particularly challenging to differentiate HP from other ILDs, also in expert contests. Radiology is playing a more crucial role in this process; recently the headcheese sign was recognized as a more specific for chronic-HP than the extensive mosaic attenuation. Several classification proposals and diagnostic models have been advanced by different groups, with no prospective validation. Therapeutic options for HP have been limited to antigen avoidance and immunosuppressant drugs over the last decades. Several questions about this condition remain unanswered and there is a need for more studies.

Influence of MUC5B gene on antisynthetase syndrome

MUC5B rs35705950 (G/T) is strongly associated with idiopathic pulmonary fibrosis (IPF) and also contributes to the risk of interstitial lung disease (ILD) in rheumatoid arthritis (RA-ILD) and chronic hypersensitivity pneumonitis (CHP). Due to this, we evaluated the implication of MUC5B rs35705950 in antisynthetase syndrome (ASSD), a pathology characterised by a high ILD incidence. 160 patients with ASSD (142 with ILD associated with ASSD [ASSD-ILD+]), 232 with ILD unrelated to ASSD (comprising 161 IPF, 27 RA-ILD and 44 CHP) and 534 healthy controls were genotyped. MUC5B rs35705950 frequency did not significantly differ between ASSD-ILD+ patients and healthy controls nor when ASSD patients were stratified according to the presence/absence of anti Jo-1 antibodies or ILD. No significant differences in MUC5B rs35705950 were also observed in ASSD-ILD+ patients with a usual interstitial pneumonia (UIP) pattern when compared to those with a non-UIP pattern. However, a statistically significant decrease of MUC5B rs35705950 GT, TT and T frequencies in ASSD-ILD+ patients compared to patients with ILD unrelated to ASSD was observed. In summary, our study does not support a role of MUC5B rs35705950 in ASSD. It also indicates that there are genetic differences between ILD associated with and that unrelated to ASSD.

Progression of fibrosing interstitial lung disease

Fibrotic interstitial lung diseases (ILDs) are often challenging to diagnose and classify, but an accurate diagnosis has significant implications for both treatment and prognosis. A subset of patients with fibrotic ILD experience progressive deterioration in lung function, physical performance, and quality of life. Several risk factors for ILD progression have been reported, such as male sex, older age, lower baseline pulmonary function, and a radiological or pathological pattern of usual interstitial pneumonia. Morphological similarities, common underlying pathobiologic mechanisms, and the consistently progressive worsening of these patients support the concept of a progressive fibrosing (PF)-ILD phenotype that can be applied to a variety of ILD subtypes. The conventional approach has been to use antifibrotic medications in patients with idiopathic pulmonary fibrosis (IPF) and immunosuppressive medications in patients with other fibrotic ILD subtypes; however, recent clinical trials have suggested a favourable treatment response to antifibrotic therapy in a wider variety of fibrotic ILDs. This review summarizes the literature on the evaluation and management of patients with PF-ILD, and discusses questions relevant to applying recent clinicial trial findings to real-world practice.

The value of serum precipitins against specific antigens in patients diagnosed with hypersensitivity pneumonitis - retrospective study

INTRODUCTION

Hypersensitivity pneumonitis (HP) is the third most common interstitial lung disease, and is often under-recognized, especially in patients who are not aware of their occupational or environmental contact with organic antigens. The aim of the present study was to assess the results of serum specific IgG antibodies (ssIgG) in HP patients and their correlation with clinical data.

MATERIAL AND METHODS

128 HP patients, median age 53 years, participated in the study. The control group consisted of 102 patients with interstitial lung diseases (ILDs) other than HP. Assessment of pretreatment ssIgG to thermophilic actinomycetes and protein antigens from bird droppings (pigeons, hens, ducks, parrots, turkeys) was performed by double diffusion in agar gel according to Ouchterlony method.

RESULTS

Positive precipitins were obtained in 57% of all HP patients and in 61% of those exposed to above mentioned antigens. Positive results in the control group were obtained in 7% of patients. Sensitivity of ssIgG in HP group was 0.57 and specificity 0.93. Precipitins to at least one bird antigen was confirmed in 64% of HP patients exposed to birds. Precipitins to thermophilic bacteria were found in 29% of HP patients exposed to hay or hay products.

CONCLUSIONS

The results of the study indicate that ssIgG against birds' allergens were the valuable diagnostic tool in HP patients. Low-rate of confirmation of ssIgG to thermophilic bacteria in patients exposed to hay or hay products indicate that other microorganisms, most likely molds, could be responsible for the disease development.

The circadian clock protein REVERBα inhibits pulmonary fibrosis development

Pulmonary inflammatory responses lie under circadian control; however, the importance of circadian mechanisms in the underlying fibrotic phenotype is not understood. Here, we identify a striking change to these mechanisms resulting in a gain of amplitude and lack of synchrony within pulmonary fibrotic tissue. These changes result from an infiltration of mesenchymal cells, an important cell type in the pathogenesis of pulmonary fibrosis. Mutation of the core clock protein REVERBα in these cells exacerbated the development of bleomycin-induced fibrosis, whereas mutation of REVERBα in club or myeloid cells had no effect on the bleomycin phenotype. Knockdown of REVERBα revealed regulation of the little-understood transcription factor TBPL1. Both REVERBα and TBPL1 altered integrinβ1 focal-adhesion formation, resulting in increased myofibroblast activation. The translational importance of our findings was established through analysis of 2 human cohorts. In the UK Biobank, circadian strain markers (sleep length, chronotype, and shift work) are associated with pulmonary fibrosis, making them risk factors. In a separate cohort, REVERBα expression was increased in human idiopathic pulmonary fibrosis (IPF) lung tissue. Pharmacological targeting of REVERBα inhibited myofibroblast activation in IPF fibroblasts and collagen secretion in organotypic cultures from IPF patients, thus suggesting that targeting of REVERBα could be a viable therapeutic approach.

Ongoing challenges in pulmonary fibrosis and insights from the nintedanib clinical programme

The approvals of nintedanib and pirfenidone changed the treatment paradigm in idiopathic pulmonary fibrosis (IPF), and increased our understanding of the underlying disease mechanisms. Nonetheless, many challenges and unmet needs remain in the management of patients with IPF and other progressive fibrosing interstitial lung diseases.This review describes how the nintedanib clinical programme has helped to address some of these challenges. Data from this programme have informed changes to the IPF diagnostic guidelines, the timing of treatment initiation, and the assessment of disease progression. The use of nintedanib to treat patients with advanced lung function impairment, concomitant emphysema, patients awaiting lung transplantation and patients with IPF and lung cancer is discussed. The long-term use of nintedanib and an up-to-date summary of nintedanib in clinical practice are discussed. Directions for future research, namely emerging therapeutic options, precision medicine and other progressive fibrosing interstitial lung diseases, are described.Further developments in these areas should continue to improve patient outcomes.

Nintedanib: New indication for systemic sclerosis-associated interstitial lung disease

Nintedanib (Ofev™), an oral triple kinase inhibitor targeting pro-fibrotic pathways, has been used for treatment of idiopathic pulmonary fibrosis (IPF). Based on positive results from phase III, placebo-controlled, randomized comparative clinical trial conducted in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD), nintedanib received marketing approval in the United States and Japan for the treatment of SSc-ILD. Nintedanib significantly reduced the annual rate of decline in forced vital capacity over 52 weeks compared with placebo. The safety profiles observed in this trial were consistent with those reported in IPF patients, and the most common adverse events were gastrointestinal disorders, including diarrhea, nausea, and vomiting, which sometimes lead to discontinuation or permanent dose reduction of nintedanib. In contrast, serious adverse events were infrequent and were related mostly to worsening of cardiopulmonary involvement of SSc. This review summarizes the milestones in development of nintedanib leading to the approval for the treatment of SSc-ILD, and covers mechanisms of action, efficacy results and safety profiles, and future perspectives of nintedanib.

Predictive factors of mortality in rheumatoid arthritis-associated interstitial lung disease analysed by modified HRCT classification of idiopathic pulmonary fibrosis according to the 2018 ATS/ERS/JRS/ALAT criteria

Background

Interstitial lung disease (ILD) is associated with high morbidity and mortality in rheumatoid arthritis (RA). Although usual interstitial pneumonia (UIP) pattern was reported as a poor prognostic factor, in clinical practice, we often cannot classify high-resolution computed tomography (HRCT) patterns specifically as UIP or nonspecific interstitial pneumonia (NSIP). This study of RA-ILD aimed to elucidate prognosis by using our modified HRCT pattern classification according to the latest guideline on idiopathic pulmonary fibrosis (IPF).

Methods

We analysed the medical records of 96 consecutive patients diagnosed as having RA-ILD. The modified HRCT classifications were defined as definite UIP, probable UIP, indeterminate for UIP (i.e., early UIP or NSIP/UIP), NSIP, organizing pneumonia (OP), NSIP+OP, and unclassifiable. Predictors of prognosis were determined using Cox regression models.

Results

Our RA-ILD cohort included definite UIP (21%), probable UIP (20%), indeterminate for UIP (30%) including NSIP/UIP (27%), alternative diagnosis (29%) including NSIP (14%), and other patterns. Interrater agreement for HRCT pattern was good (κ=0.75). Multivariate analysis showed that older age, history of acute exacerbation, and radiological honeycombing were negative prognostic factors of mortality.

Conclusions

NSIP/UIP pattern of indeterminate for UIP was the major pattern in RA-ILD. Although classifications of HRCT patterns were not related to survival, the presence of radiological honeycombing could be a useful predictor of poor prognosis, and acute exacerbation of ILD can seriously impact patient survival regardless of the presence of a UIP or indeterminate for UIP pattern. Our modified HRCT classification based on the latest IPF guideline might be useful to assess appropriate strategies of diagnosis in future RA-ILD studies, and radiological honeycombing could better predict poor prognosis rather than HRCT pattern.

Endotype-phenotyping may predict a treatment response in progressive fibrosing interstitial lung disease

BACKGROUND

Some interstitial lung disease (ILD) patients develop a progressive fibrosing-ILD phenotype (PF-ILD), with similar persistent lung function decline suggesting common molecular pathways involved. Nintedanib, a tyrosine kinase inhibitor targeting the PDGF, FGF, VEGF and M-CSF pathways, has shown comparable efficacy in idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated ILD (SSc-ILD). We hypothesize that Nintedanib targeted molecular pathways will be augmented to a similar degree across PF-ILD regardless of aetiology.

METHODS

We collected explanted lung tissue at the time of lung transplantation from 130 PF-ILD patients (99 (76%) IPF, 14 (11%) SSc-ILD, 17 (13%) other PF-ILD), and wedge biopsies from 200 donor lungs and measured PDGF, FGF, VEGF and M-CSF concentrations by Luminex.

FINDINGS

The concentrations of PDGF-AA, PDGF-BB, FGF-2, VEGF and M-CSF were significantly increased in PF-ILD lungs compared to donor lungs (PDGF-AA 93·0 pg/ml [±97·2] vs. 37·5 pg/ml [±35·4], p < 0·001; PDGF-BB 102·5 pg/ml [±78·8] vs. 61·9 pg/ml [±47·0], p < 0·001; FGF-2 1442·4 pg/ml [±426·6] vs. 1201·7 pg/ml [±535·2], p = 0·009; VEGF 40·6 pg/ml [±20·1] vs. 24·9 pg/ml [±29·5], p < 0·001; and M-CSF 25526 pg/ml [±24,799] vs. 6120 pg/ml [±7245], p < 0·001). There were no significant differences in these growth factor/angiogenic molecules/cytokine concentrations when segregated by IPF, SSc-ILD and other PF-ILDs.

INTERPRETATION

Nintedanib specific targeted molecular pathways are augmented to a similar magnitude in all PF-ILD lung tissue as compared to controls, suggesting that Nintedanib treatment may be efficacious in PF-ILD regardless of aetiology. We speculate that clinical trials using Nintedanib for PF-ILD with or without IPF or SSc-ILD should show a similar relative reduction in FVC decline as seen in IPF and SSc-ILD (∼45-50%).

FUNDING

Health Grant P01-HL108793 (JAB), South-Eastern Norway Regional Health Authority Grant 2018072 (AMHV).

[Treatment of systemic sclerosis-associated interstitial lung disease]

BACKGROUND

Systemic sclerosis (SSc) is a fibrosing autoimmune disease of the connective tissue. In addition to skin fibrosis, pulmonary involvement and interstitial lung disease (ILD) in particular are the most common and severe manifestations of SSc. The disease is associated with a substantial risk of morbidity and mortality, especially in progressive ILD. In the last 5 years new treatment concepts for SSc-ILD have been investigated in numerous clinical studies.

MATERIAL AND METHODS

This review is based on a literature search in PubMed, focusing on the most relevant papers published up to the end of 2018 with the keywords "SSc" and "treatment".

RESULTS

The treatment of SSc-ILD has changed over the last few years due to the results of many clinical studies. The updated guidelines of the European League Against Rheumatism (EULAR) recommend the use of cyclophosphamide or hematopoietic stem cell transplantation. Data for a positive influence on SSc-ILD are also available for mycophenolate, tocilizumab and anabasum. Because of the pathophysiological similarities to idiopathic pulmonary fibrosis, the use of the antifibrotic agents nintedanib and pirfenidone is currently being investigated in randomized, multicenter clinical trials and could be a novel and promising therapeutic strategy.

CONCLUSION

Current drug studies may provide innovative therapeutic perspectives for SSc-ILD and could significantly improve the prognosis of affected patients in the future.

Possible value of antifibrotic drugs in patients with progressive fibrosing non-IPF interstitial lung diseases

BACKGROUND

Fibrosing, non-idiopathic pulmonary fibrosis (non-IPF) interstitial lung diseases (fILDs) are a heterogeneous group of diseases characterized by a different amount of inflammation and fibrosis. Therapy is currently based on corticosteroids and/or immunomodulators. However, response to these therapies is highly variable, sometimes without meaningful improvement, especially in more fibrosing forms. Pirfenidone and nintedanib have recently demonstrated to reduce functional decline in patients with IPF. However, their antifibrotic mechanism makes these two drugs an interesting approach for treatment of fibrosing ILDs other than IPF.

OBJECTIVES

We here report our experience with antifibrotic drugs in fibrosing non-IPF ILDs patients having a progressive phenotype during immunosuppressive therapy.

METHODS

Patients with a multidisciplinary team diagnosis of fibrosing non-IPF ILDs experiencing a progressive phenotype during treatment with corticosteroids and/or immunomodulators between October-2014 and January-2018 at our tertiary referral Center for ILDs were retrospectively analyzed. Antifibrotic therapy was administered after application with the respective health insurance company and after consent by the patient. Pulmonary-function-tests and follow-up visits were performed every 6 ± 1 months.

RESULTS

Eleven patients were treated with antifibrotic drugs (8 males, mean age 62 ± 12.8 years, mean FVC% 62.8 ± 22.3, mean DLCO% 35.5 ± 10.7, median follow-up under antifibrotic treatment 11.1 months). Patients had a diagnosis of unclassifiable ILD in 6 cases, pleuroparenchymal fibroelastosis in 2 cases, idiopathic-NSIP in 1 case, asbestos-related ILD in 1 case and Hermansky-Pudlak syndrome in 1 case. Treatment before antifibrotics consisted of corticosteroids in all patients: 5 combined with Azathioprin, 1 with either methotrexate or cyclophosphamide (i.v.). Ten patients were treated with pirfenidone (2403 mg/die) and 1 with nintedanib (300 mg/die). Median FVC was 56, 56, 50%, at time points - 24, - 12, - 6 before initiation, 44% at time of initiation and 46.5% at 6 months after initiation of antifibrotic treatment. Antifibrotic treatment was generally well tolerated with a need of dose reduction in 2 cases (rash and nausea) and early termination in 3 cases.

CONCLUSIONS

Antifibrotic treatment may be a valuable treatment option in patients with progressive fibrosing non-IPF ILD if currently no other treatment options exist. However, prospective, randomized clinical trials are urgently needed to assess the real impact of antifibrotic therapy in these patients.

Idiopathic and immune-related pulmonary fibrosis: diagnostic and therapeutic challenges

Interstitial lung disease (ILD) encompasses a large group of pulmonary conditions sharing common clinical, radiological and histopathological features as a consequence of fibrosis of the lung interstitium. The majority of ILDs are idiopathic in nature with possible genetic predisposition, but is also well recognised as a complication of connective tissue disease or with certain environmental, occupational or drug exposures. In recent years, a concerted international effort has been made to standardise the diagnostic criteria in ILD subtypes, formalise multidisciplinary pathways and standardise treatment recommendations. In this review, we discuss some of the current challenges around ILD diagnostics, the role of serological testing, especially, in light of the new classification of Interstitial Pneumonia with Autoimmune Features (IPAF) and discuss the evidence for therapies targeted at idiopathic and immune-related pulmonary fibrosis.

Antifibrotic therapy for fibrotic lung disease beyond idiopathic pulmonary fibrosis

Two antifibrotic medications (nintedanib and pirfenidone) were recommended (conditionally) for the treatment of patients with idiopathic pulmonary fibrosis (IPF) in the 2015 IPF evidence-based guidelines. These medications have been shown to reduce the rate of decline in forced vital capacity among patients with IPF over time and are the only two disease-modulating pharmacological agents approved by regulatory agencies and available for clinical use worldwide. With the evolved standard of care for interstitial lung disease evaluation including routine use of high-resolution computed tomography, fibrotic lung diseases other than IPF are increasingly recognised. In addition, it is becoming evident that genetic and pathophysiological mechanisms as well as disease behaviour in patients manifesting other "non-IPF progressive fibrotic interstitial lung diseases" (non-IPF-PF) may be similar to those in patients with IPF. Thus, it is biologically plausible that pharmacological agents with antifibrotic properties may be efficacious in non-IPF-PF. Indeed, studies are underway or planned to assess the safety and efficacy of nintedanib or pirfenidone among patients with several non-IPF fibrotic lung diseases. In this review, we briefly summarise the use of pirfenidone and nintedanib in IPF as well as the rationale and potential for use of these medications in non-IPF-PF that are being investigated in ongoing and upcoming clinical trials.

Prediction of idiopathic pulmonary fibrosis progression using early quantitative changes on CT imaging for a short term of clinical 18-24-month follow-ups

OBJECTIVE

High-resolution computed tomography (HRCT) plays an indispensable role in the diagnosis of idiopathic pulmonary fibrosis (IPF). Due to unpredictability in progression and the short median survival of 2-5 years, it is critical to delineate the patients with rapid progression. The aim is to evaluate the predictability of IPF progression using the early quantitative changes.

METHODS

Automated texture-based quantitative lung fibrosis (QLF) was calculated from the anonymized HRCT. Two datasets were collected retrospectively: (1) a pilot study of 35 subjects with three sequential scans (baseline and 6 and 12 months) to obtain a threshold, where visual assessments were stable at 6 months but worsened at 12 months; (2) 157 independent subjects to test the threshold. Landmark Cox regressions were used to compare the progression-free survival (PFS) defined by pulmonary function using the threshold from the early changes in QLF. C-indexes were reported as estimations of the concordance of prediction.

RESULTS

A threshold of 4% QLF change at 6 months corresponded to the mean change that worsened on HRCT visually at 12 months from the pilot study. Using the threshold, significant differences were found in the independent dataset (hazard ratio (HZ) = 5.92, p = 0.001 by Cox model, C-index = 0.71 at the most severe lobe; and HZ = 3.22, p = 0.012, C-index = 0.68 in the whole lung). Median PFS was 11.9 months for subjects with ≥ 4% changes, whereas median PFS was greater than 18 months for subjects with < 4% changes at the most severe lobe.

CONCLUSION

Early structural changes on HRCT using a quantitative score can predict progression in lung function.

KEY POINTS

• Changes on HRCT using quantitative texture-based scores can play a pivotal role for providing information and an aid tool for timely management decision for patients with IPF. • Quantitative changes on HRCT of 4% or more, which matched 6-month prior changes with visual assessment of worsening, can play a pivotal role for providing prediction of clinical progression by 3-5 folds higher in the next incidence, compared with those of subjects with less than 4% changes. • Early structural changes of 4% or more in a paired HRCT scans derived by quantitative scores can predict the progression in lung function in 1-2 years in subjects with IPF, which is critical information for timely management decision for subjects with IPF where the median survival is 2 to 5 years.

DROSHA-Dependent AIM2 Inflammasome Activation Contributes to Lung Inflammation during Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) has been linked to chronic lung inflammation. Drosha ribonuclease III (DROSHA), a class 2 ribonuclease III enzyme, plays a key role in microRNA (miRNA) biogenesis. However, the mechanisms by which DROSHA affects the lung inflammation during idiopathic pulmonary fibrosis (IPF) remain unclear. Here, we demonstrate that DROSHA regulates the absent in melanoma 2 (AIM2) inflammasome activation during idiopathic pulmonary fibrosis (IPF). Both DROSHA and AIM2 protein expression were elevated in alveolar macrophages of patients with IPF. We also found that DROSHA and AIM2 protein expression were increased in alveolar macrophages of lung tissues in a mouse model of bleomycin-induced pulmonary fibrosis. DROSHA deficiency suppressed AIM2 inflammasome-dependent caspase-1 activation and interleukin (IL)-1β and IL-18 secretion in primary mouse alveolar macrophages and bone marrow-derived macrophages (BMDMs). Transduction of microRNA (miRNA) increased the formation of the adaptor apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks, which is required for AIM2 inflammasome activation in BMDMs. Our results suggest that DROSHA promotes AIM2 inflammasome activation-dependent lung inflammation during IPF.

Healthcare utilisation and costs in the diagnosis and treatment of progressive-fibrosing interstitial lung diseases

There are over 200 interstitial lung diseases (ILDs). In addition to patients with idiopathic pulmonary fibrosis (IPF), a percentage of patients with other ILDs also develop progressive fibrosis of the lung during their disease course. Patients with progressive-fibrosing ILDs may show limited response to immunomodulatory therapy, worsening symptoms and lung function and, ultimately, early mortality. There are few data for ILDs that may present a progressive fibrosing phenotype specifically, but we believe the burden and healthcare costs associated with these conditions may be comparable to those reported in IPF. This review discusses the burden of ILDs that may present a progressive fibrosing phenotype and the factors impacting healthcare utilisation.

Role of imaging in progressive-fibrosing interstitial lung diseases

Imaging techniques are an essential component of the diagnostic process for interstitial lung diseases (ILDs). Chest radiography is frequently the initial indicator of an ILD, and comparison of radiographs taken at different time points can show the rate of disease progression. However, radiography provides only limited specificity and sensitivity and is primarily used to rule out other diseases, such as left heart failure. High-resolution computed tomography (HRCT) is a more sensitive method and is considered central in the diagnosis of ILDs. Abnormalities observed on HRCT can help identify specific ILDs. HRCT also can be used to evaluate the patient's prognosis, while disease progression can be assessed through serial imaging. Other imaging techniques such as positron emission tomography-computed tomography and magnetic resonance imaging have been investigated, but they are not commonly used to assess patients with ILDs. Disease severity may potentially be estimated using quantitative methods, as well as visual analysis of images. For example, comprehensive assessment of disease staging and progression in patients with ILDs requires visual analysis of pulmonary features that can be performed in parallel with quantitative analysis of the extent of fibrosis. New approaches to image analysis, including the application of machine learning, are being developed.

Imaging techniques, particularly HRCT, are the cornerstone for ILD diagnosis and new approaches to analysing HRCT images, including machine-learning technology, are being developedhttp://ow.ly/1R1e30mOqhn

The epidemiology of idiopathic pulmonary fibrosis and interstitial lung diseases at risk of a progressive-fibrosing phenotype

The availability of epidemiological data relating to interstitial lung diseases (ILDs) has increased over recent years, but information on the prevalence and incidence of ILDs of different aetiologies remains limited. Despite global distribution, the proportion of patients who develop a progressive phenotype across different ILDs is not well known. Disease behaviour is well documented in idiopathic pulmonary fibrosis but idiosyncratic in other ILDs that may present a progressive fibrosing phenotype. Possible reasons may include the heterogeneous nature of the aetiology, the complexity of diagnosis (and subsequent documentation of cases) and the methods employed to retrospectively analyse patient databases. This review presents a broad overview of the epidemiological data available for ILDs that may present a progressive-fibrosing phenotype, collectively and stratified according to clinical classification. We also note where further data are needed in comparison to the well-studied IPF indication.