Validation of Proposed Criteria for Progressive Pulmonary Fibrosis

Natural history of indolent-anti-synthetase syndrome-associated interstitial lung disease

BACKGROUND

Anti-synthetase syndrome-associated interstitial lung disease (ASS-ILD) may occur without myositis. Although a recent Japanese guide proposed a watch-and-wait approach for chronic ASS-ILD without obvious progression, the natural history of this subgroup and the appropriateness of the watch-and-wait approach remain unclear. We aimed to describe the natural history of ASS-ILD, that is sufficiently indolent to be a candidate for the watch-and-wait approach.

METHODS

Among consecutive patients with ASS-ILD, we retrospectively identified those without myositis, acute/subacute onset, and significant lung function impairment, which qualified them as indolent-ASS-ILD cases, and described their natural course. Additionally, we evaluated the risk factors for fibrosis progression on computed tomography (CT) using the Cox proportional hazards model.

RESULTS

Among 80 patients with ASS-ILD, we identified 33 with indolent-ASS-ILD, all of whom were initially followed up with a watch-and-wait approach. Among 30 patients with sufficient follow-up data, 27 (90%) showed a stable course without treatment over 24 months. Subsequently, four patients experienced ≥10% relative forced vital capacity (FVC) decline without treatment during a median follow-up duration of 81 months. Seven patients showed fibrosis progression with >10% increase in the total lung area on CT. Higher levels of Krebs von den Lungen-6 (KL-6) and surfactant protein-D (SP-D) were associated with fibrosis progression on CT.

CONCLUSION

Most patients with indolent-ASS-ILD did not experience ≥10% relative FVC decline over five years without treatment. However, fibrosis progression on CT, which seemed to precede significant FVC decline, occurred more frequently, especially in patients with higher KL-6 and SP-D levels.

Evaluation of progressive pulmonary fibrosis in non-idiopathic pulmonary fibrosis-interstitial lung diseases: a cross-sectional study

BACKGROUND

Progressive pulmonary fibrosis is the symptomatic, physiological, and radiological progression of interstitial lung diseases. The aim of this study was to examine the relationship between progressive pulmonary fibrosis and demographic characteristics and to evaluate the effect on clinical outcomes and mortality.

METHODS

This cross-sectional study included 221 patients diagnosed with non-idiopathic pulmonary fibrosis interstitial lung diseases who were followed in the last 5 years. Patient symptoms, clinical, radiological, and demographic data were examined. Risk factors for the development of progressive pulmonary fibrosis and the relationship with clinical outcomes and mortality were examined.

RESULTS

Of the patients, 33.0% (n = 73) had fibrotic idiopathic nonspecific interstitial pneumonia (iNSIP), 35.7% (n = 79) had fibrotic hypersensitivity pneumonia (HP), 18.1% (n = 40) had fibrotic connective tissue disease (CTD) interstitial lung diseases (ILD), and 13.1% (n = 29) had postinfectious fibrotic ILD. The progressive pulmonary fibrosis development rates of the subtypes were 46.5% iNSIP (n = 34), 86.0% fibrotic HP (n = 68), 42.5% fibrotic CTD-ILD (n = 17), and 20.7% postinfectious ILD (n = 6). The presence of progressive pulmonary fibrosis was associated with the development of respiratory failure and mortality (odds ratio [OR]: 2.70, 95% CI: 1.04-7.05 and OR: 2.13, 95% CI: 1.23-3.69). Progressive pulmonary fibrosis development was higher in hypersensitivity pneumonia patients with farmer's lung (OR: 5.06, 95% CI: 1.02-25.18).

CONCLUSION

Progressive pulmonary fibrosis was more prevalent in older patients. Farming was an important risk factor in the development of hypersensitivity pneumonia-progressive pulmonary fibrosis. Respiratory failure and mortality were higher in those who developed progressive pulmonary fibrosis.

Deep Learning-based Segmentation of Computed Tomography Scans Predicts Disease Progression and Mortality in Idiopathic Pulmonary Fibrosis

Rationale: Despite evidence demonstrating a prognostic role for computed tomography (CT) scans in idiopathic pulmonary fibrosis (IPF), image-based biomarkers are not routinely used in clinical practice or trials. Objectives: To develop automated imaging biomarkers using deep learning-based segmentation of CT scans. Methods: We developed segmentation processes for four anatomical biomarkers, which were applied to a unique cohort of treatment-naive patients with IPF enrolled in the PROFILE (Prospective Observation of Fibrosis in the Lung Clinical Endpoints) study and tested against a further United Kingdom cohort. The relationships among CT biomarkers, lung function, disease progression, and mortality were assessed. Measurements and Main Results: Data from 446 PROFILE patients were analyzed. Median follow-up duration was 39.1 months (interquartile range, 18.1-66.4 mo), with a cumulative incidence of death of 277 (62.1%) over 5 years. Segmentation was successful on 97.8% of all scans, across multiple imaging vendors, at slice thicknesses of 0.5-5 mm. Of four segmentations, lung volume showed the strongest correlation with FVC (r = 0.82; P < 0.001). Lung, vascular, and fibrosis volumes were consistently associated across cohorts with differential 5-year survival, which persisted after adjustment for baseline gender, age, and physiology score. Lower lung volume (hazard ratio [HR], 0.98 [95% confidence interval (CI), 0.96-0.99]; P = 0.001), increased vascular volume (HR, 1.30 [95% CI, 1.12-1.51]; P = 0.001), and increased fibrosis volume (HR, 1.17 [95% CI, 1.12-1.22]; P < 0.001) were associated with reduced 2-year progression-free survival in the pooled PROFILE cohort. Longitudinally, decreasing lung volume (HR, 3.41 [95% CI, 1.36-8.54]; P = 0.009) and increasing fibrosis volume (HR, 2.23 [95% CI, 1.22-4.08]; P = 0.009) were associated with differential survival. Conclusions: Automated models can rapidly segment IPF CT scans, providing prognostic near and long-term information, which could be used in routine clinical practice or as key trial endpoints.

Highlights on Future Treatments of IPF: Clues and Pitfalls

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease characterized by irreversible scarring of lung tissue, leading to death. Despite recent advancements in understanding its pathophysiology, IPF remains elusive, and therapeutic options are limited and non-curative. This review aims to synthesize the latest research developments, focusing on the molecular mechanisms driving the disease and on the related emerging treatments. Unfortunately, several phase 2 studies showing promising preliminary results did not meet the primary endpoints in the subsequent phase 3, underlying the complexity of the disease and the need for new integrated endpoints. IPF remains a challenging condition with a complex interplay of genetic, epigenetic, and pathophysiological factors. Ongoing research into the molecular keystones of IPF is critical for the development of targeted therapies that could potentially stop the progression of the disease. Future directions include personalized medicine approaches, artificial intelligence integration, growth in genetic insights, and novel drug targets.

Forced vital capacity trajectories and risk of lung transplant and ILD-related mortality among patients with rheumatoid arthritis-associated interstitial lung disease

We aimed to determine the prevalence and outcomes for forced vital capacity percent predicted (FVCpp) decline among patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). We identified patients with RA-ILD in the Mass General Brigham Healthcare system. RA-ILD diagnosis was determined by review of high-resolution computed tomography (HRCT) imaging by up to three thoracic radiologists. We abstracted FVCpp measurements, covariates, lung transplant, and ILD-related death from the medical record. We employed a relative FVCpp decline cutoff of > 10% within 24 months. We also used a group-based trajectory model to obtain patterns of change from RA-ILD diagnosis. We then assessed for associations of each FVC decline definition with risk of lung transplant or ILD-related death using multivariable logistic regression. We analyzed 172 patients with RA-ILD with a median of 6 FVCpp measurements per patient over 6.5 years of follow-up (mean age 62.2 years, 36% male). There were seven (4%) lung transplants and 44 (26%) ILD-related deaths. Ninety-eight (57%) patients had relative decline of FVCpp by > 10% in 24 months. We identified three trajectory groups of FVCpp change: rapidly declining (n = 24/168 [14%]), slowly declining (n = 90/168 [54%]), and stable/improving (n = 54/168 [32%]). The rapidly declining group and FVCpp > 10% had adjusted odds ratios (aOR) for lung transplant/ILD-related death of 19.2 (95%CI 4.9 to 75.5) and 2.8 (95%CI 1.3 to 6.1) respectively. Over half of patients with RA-ILD had declining FVCpp. The different trajectory patterns demonstrate the importance of FVC monitoring for identifying patients at the highest risk of poor outcomes. Key Points • Over half of patients with RA-ILD had declining FVCpp over a median of 6.5 years of follow-up. • The rapidly declining FVCpp trajectory group had stronger associations with lung transplant and ILD-related death compared to those with FVCpp decline by > 10%. • Clinicians can employ FVC monitoring to proactively treat patients who are at risk of poor outcomes.

[Interstitial lung diseases : From imaging to treatment]

BACKGROUND

The role of radiology in the diagnosis of interstitial lung diseases (ILDs) has evolved over time, in part replacing histology. Radiology now represents a pillar of diagnostics and monitoring in ILDs.

OBJECTIVE

To what extent does radiology influence diagnostics and treatment in ILDs?

MATERIALS AND METHODS

A literature review was conducted, and current findings were discussed in the context of clinical data.

RESULTS

Radiology plays a crucial role in the diagnosis of ILDs. Within the framework of the multidisciplinary conference, it provides specific CT patterns such as usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), and organizing pneumonia (OP), or helps in identifying cystic lung diseases. Multicompartment diseases can be detected, and pulmonary hypertension or extrapulmonary involvement of the respective diseases can be suspected. Progressive pulmonary fibrosis requires radiologic assessment as one of the required criteria. Interstitial lung abnormalities are usually detected by radiological studies performed for an unrelated indication.

CONCLUSION

Radiology plays an important role within the multidisciplinary conference to determine both diagnosis and treatment with antifibrotic or anti-inflammatory drugs, or a combination of both.

Use of Race-Specific Equations in Pulmonary Function Tests Impedes Potential Eligibility for Care and Treatment of Pulmonary Fibrosis

Rationale: The use of race-specific reference values to evaluate pulmonary function has long been embedded into clinical practice; however, there is a growing consensus that this practice may be inappropriate and that the use of race-neutral equations should be adopted to improve access to health care. Objectives: To evaluate whether the use of race-neutral equations to assess percent predicted forced vital capacity (FVC%pred) impacts eligibility for clinical trials, antifibrotic therapy, and referral for lung transplantation in Black, Hispanic/Latino, and White patients with interstitial lung disease (ILD). Methods: FVC%pred values for patients from the Pulmonary Fibrosis Foundation Patient Registry were calculated using race-specific (Hankinson and colleagues, 1999), race-agnostic (Global Lung Function Initiative [GLI]-2012), and race-neutral (GLI-2022 or GLI-Global) equations. Eligibility for ILD clinical trials (FVC%pred >45% and <90%), antifibrotic therapy (FVC%pred >55% and <82%), and lung transplantation referral (FVC%pred <70%) based on GLI-2022 and GLI-2012 equations were compared with those based on the Hankinson 1999 equation. Results: Baseline characteristics were available for 1,882 patients (Black, n = 104; Hispanic/Latino, n = 103; White, n = 1,675), and outcomes were evaluated in 1,531 patients with FVC%pred within ±90 days of registry enrollment (Black, n = 78; Hispanic/Latino, n = 72; White, n = 1,381). Black patients were younger at the time of consent and more likely to be female compared with Hispanic/Latino or White patients. Compared with GLI-2022, the Hankinson 1999 equation misclassified 22% of Black patients, 14% of Hispanic/Latino patients, and 12% of White patients for ILD clinical trial eligibility; 21% of Black patients, 17% of Hispanic/Latino patients, and 19% of White patients for antifibrotic therapy eligibility; and 6% of Black patients, 14% of Hispanic/Latino patients, and 12% of White patients for lung transplantation referral. Similar trends were observed when comparing the GLI-2012 and Hankinson 1999 equations. Conclusions: Misclassification of patients for critical interventions is highly prevalent when using the Hankinson 1999 equation and highlights the need to consider adopting the race-neutral GLI-2022 equation for enhanced accuracy and more equitable representation in pulmonary health care. Our results make a compelling case for reevaluating the use of race as a physiological variable and emphasize the pressing need for continuous innovation to ensure equal and optimal care for all patients regardless of their race or ethnicity. Clinical trial registered with www.clinicaltrials.gov (NCT02758808).

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Three-dimensional cultured human umbilical cord mesenchymal stem cells attenuate pulmonary fibrosis by improving the balance of mitochondrial fusion and fission

Pulmonary fibrosis is a kind of fibrotic interstitial pneumonia with poor prognosis. Aging, environmental pollution, and coronavirus disease 2019 are considered as independent risk factors for pulmonary fibrogenesis. Consequently, the morbidity and mortality striking continues to rise in recent years. However, the clinical therapeutic efficacy is very limited and unsatisfactory. So it is necessary to develop a new effective therapeutic approach for pulmonary fibrosis. Human umbilical cord mesenchymal stem cells (hucMSCs) are considered as a promising treatment for various diseases because of their multiple differentiation and immunomodulatory function. The key bottleneck in the clinical application of hucMSCs therapy is the high-quality and large-scale production. This study used FloTrix miniSpin bioreactor, a three-dimensional (3D) cell culture system, for large-scale expansion of hucMSCs in vitro, and proved 3D cultured hucMSCs inhibited the differentiation of fibroblasts into myofibroblasts and myofibroblasts proliferation and migration, leading to slow down the development of pulmonary fibrosis. Further mechanistic studies clarified that hucMSCs reduced the amount of binding between circELP2 and miR-630, resulting in blocking YAP/TAZ translocation from cytoplasm to nucleus. This condition inhibited mitochondrial fusion and promoted mitochondrial fission, and ultimately improved fusion/fission balance and cellular homeostasis. To sum up, this work clarified the anti-fibrosis and mechanism of hucMSCs cultured from the 3D FloTrix miniSpin bioreactor. We hope to provide new ideas and new methods for the clinical transformation and industrialization of hucMSCs therapy.

A multidimensional classifier to support lung transplant referral in patients with pulmonary fibrosis

BACKGROUND

Lung transplantation remains the sole curative option for patients with idiopathic pulmonary fibrosis (IPF), but donor organs remain scarce, and many eligible patients die before transplant. Tools to optimize the timing of transplant referrals are urgently needed.

METHODS

Least absolute shrinkage and selection operator was applied to clinical and proteomic data generated as part of a prospective cohort study of interstitial lung disease (ILD) to derive clinical, proteomic, and multidimensional logit models of near-term death or lung transplant within 18 months of blood draw. Model-fitted values were dichotomized at the point of maximal sensitivity and specificity, and decision curve analysis was used to select the best-performing classifier. We then applied this classifier to independent IPF and non-IPF ILD cohorts to determine test performance characteristics. Cohorts were restricted to patients aged ≤72 years with body mass index 18 to 32 to increase the likelihood of transplant eligibility.

RESULTS

IPF derivation, IPF validation, and non-IPF ILD validation cohorts consisted of 314, 105, and 295 patients, respectively. A multidimensional model comprising 2 clinical variables and 20 proteins outperformed stand-alone clinical and proteomic models. Following dichotomization, the multidimensional classifier predicted near-term outcome with 70% sensitivity and 92% specificity in the IPF validation cohort and 70% sensitivity and 80% specificity in the non-IPF ILD validation cohort.

CONCLUSIONS

A multidimensional classifier of near-term outcomes accurately discriminated this end-point with good test performance across independent IPF and non-IPF ILD cohorts. These findings support refinement and prospective validation of this classifier in transplant-eligible individuals.

Prevalence of Progressive Fibrosing Interstitial Lung Disease in Patients with Primary Sjogren Syndrome

BACKGROUND

Interstitial lung disease (ILD) represents a frequent cause of morbidity and mortality in primary Sjogren syndrome (pSS). However, the prevalence and behavior of pSS-ILD remains incomplete, largely based on retrospective heterogeneous studies.

AIM OF THE STUDY

To investigate the prevalence of progressive pulmonary fibrosis (PPF) in a multicentric cohort of patients with pSS-ILD. Additionally, this study explored possible correlations between PPF and clinical, demographic, and serological features of pSS.

METHODS

All consecutive patients with pSS-ILD were enrolled in a 6-month period. Clinical, demographic, and serological features of pSS, other than functional and radiological lung features, were collected. Clinical behaviors of ILD other than PPF were also investigated.

RESULTS

Seventy-two patients were enrolled. A fibrosing ILD pattern was observed in 65.3% of patients with pSS-ILD; among them, 55.3% showed a PPF. The radiologic pattern (NSIP, UIP, or others) was not associated with PPF; in particular, patients with PFF had UIP in 42.3% of cases and NSIP in 57.7%, without a significant difference with respect to the non-PPF group (p = 0.29). Shorter pSS disease duration, higher age at pSS diagnosis, and lower frequency of antinuclear antibodies were correlated with the PPF subgroup. However, multivariate analysis did not confirm these associations.

DISCUSSION

This study provides valuable insights into the prevalence and characteristics of PPF in pSS-ILD. In particular, UIP and NSIP showed a similar evolution towards PPF in patients with pSS; for NSIP, this behavior was more frequent than for other rheumatic diseases. Our results emphasize the importance of early recognition of PPF for timely intervention and careful follow-up.

CONCLUSIONS

This study provides valuable insights into the prevalence and characteristics of PPF in pSS-ILD. In particular, UIP and NSIP showed a similar evolution towards PPF in patients with pSS; for NSIP, this behavior was more frequent than for other rheumatic diseases. Our results emphasize the importance of early recognition of PPF for timely intervention and careful follow-up.

Emerging roles of ferroptosis in pulmonary fibrosis: current perspectives, opportunities and challenges

Pulmonary fibrosis (PF) is a chronic interstitial lung disorder characterized by abnormal myofibroblast activation, accumulation of extracellular matrix (ECM), and thickening of fibrotic alveolar walls, resulting in deteriorated lung function. PF is initiated by dysregulated wound healing processes triggered by factors such as excessive inflammation, oxidative stress, and coronavirus disease (COVID-19). Despite advancements in understanding the disease's pathogenesis, effective preventive and therapeutic interventions are currently lacking. Ferroptosis, an iron-dependent regulated cell death (RCD) mechanism involving lipid peroxidation and glutathione (GSH) depletion, exhibits unique features distinct from other RCD forms (e.g., apoptosis, necrosis, and pyroptosis). Imbalance between reactive oxygen species (ROS) production and detoxification leads to ferroptosis, causing cellular dysfunction through lipid peroxidation, protein modifications, and DNA damage. Emerging evidence points to the crucial role of ferroptosis in PF progression, driving macrophage polarization, fibroblast proliferation, and ECM deposition, ultimately contributing to alveolar cell death and lung tissue scarring. This review provides a comprehensive overview of the latest findings on the involvement and signaling mechanisms of ferroptosis in PF pathogenesis, emphasizing potential novel anti-fibrotic therapeutic approaches targeting ferroptosis for PF management.

Usefulness of CT Quantification-Based Assessment in Defining Progressive Pulmonary Fibrosis

RATIONALE AND OBJECTIVES

To establish a quantitative CT threshold for radiological disease progression of progressive pulmonary fibrosis (PPF) and evaluate its feasibility in patients with connective tissue disease-related interstitial lung disease (CTD-ILD).

MATERIALS AND METHODS

Between April 2007 and October 2022, patients diagnosed with CTD-ILD retrospectively evaluated. CT quantification was conducted using a commercial software by summing the percentages of ground-glass opacity, consolidation, reticular opacity, and honeycombing. The quantitative threshold for radiological progression was determined based on the highest discrimination on overall survival (OS). Two thoracic radiologists independently evaluated visual radiological progression, and the senior radiologist's assessment was used as the final result. Cox regression was used to assess prognosis of PPF based on the visual assessment and quantitative threshold.

RESULTS

97 patients were included and followed up for a median of 30.3 months (range, 4.7-198.1 months). For defining radiological disease progression, the optimal quantitative CT threshold was 4%. Using this threshold, 12 patients were diagnosed with PPF, while 14 patients were diagnosed with PPF based on the visual assessment, with an agreement rate of 97.9% (95/97). Worsening respiratory symptoms (hazard ratio [HR], 12.73; P < .001), PPF based on the visual assessment (HR, 8.86; P = .002) and based on the quantitative threshold (HR, 6.72; P = .009) were independent risk factors for poor OS.

CONCLUSION

The quantitative CT threshold for radiological disease progression (4%) was feasible in defining PPF in terms of its agreement with PPF grouping and prognostic performance when compared to visual assessment.

Proportion and predictors of FVC decline in patients with interstitial lung disease

RATIONALE

The proportion of patients who develop progressive pulmonary fibrosis (PPF), along with risk factors for progression remain poorly understood.

OBJECTIVES

To examine factors associated with an increased risk of developing PPF among patients at a referral center.

METHODS

We identified patients with a diagnosis of interstitial lung disease (ILD) seen within the Cleveland Clinic Health System. Utilizing a retrospective observational approach we estimated the risk of developing progression by diagnosis group and identified key clinical predictors using the FVC component of both the original progressive fibrotic interstitial lung disease (PFILD) and the proposed PPF (ATS) criteria.

RESULTS

We identified 5934 patients with a diagnosis of ILD. The cumulative incidence of progression over the 24 months was similar when assessed with the PFILD and PPF criteria (33.1 % and 37.9 % respectively). Of those who met the ATS criteria, 9.5 % did not meet the PFILD criteria. Conversely, 4.3 % of patients who met PFILD thresholds did not achieve the 5 % absolute FVC decline criteria. Significant differences in the rate of progression were seen based on underlying diagnosis. Steroid therapy (HR 1.46, CI 1.31-1.62) was associated with an increased risk of progressive fibrosis by both PFILD and PPF criteria.

CONCLUSION

Regardless of the definition used, the cumulative incidence of progressive disease is high in patients with ILD in the 24 months following diagnosis. Some differences are seen in the risk of progression when assessed by PFILD and PPF criteria. Further work is needed to identify modifiable risk factors for the development of progressive fibrosis.

Overview of Rheumatoid Arthritis-Associated Interstitial Lung Disease and Its Treatment

Interstitial lung disease (ILD) is a common pulmonary complication of rheumatoid arthritis (RA), causing significant morbidity and mortality. Optimal treatment for RA-ILD is not yet well defined. Reliable prognostic indicators are largely byproducts of prior ILD progression, including low or decreasing forced vital capacity and extensive or worsening fibrosis on imaging. In the absence of validated tools to predict treatment response, decisions about whether to initiate or augment treatment are instead based on clinical judgment. In general, treatment should be initiated in patients who are symptomatic, progressing, or at high risk of poor outcomes. Retrospective data suggest that mycophenolate mofetil, azathioprine, and rituximab are likely effective therapies for RA-ILD. Abatacept is also emerging as a potential first-line treatment option for patients with RA-ILD. Further, recent data demonstrate that immunosuppression may be beneficial even in patients with a usual interstitial pneumonia (UIP) pattern on imaging, suggesting that immunosuppression should be considered irrespective of imaging pattern. Recent randomized controlled trials have shown that antifibrotic medications, such as nintedanib and likely pirfenidone, slow forced vital capacity decline in RA-ILD. Consideration can be given to antifibrotic initiation in patients progressing despite immunosuppression, particularly in patients with a UIP pattern. Future research directions include developing tools to predict which patients will remain stable from patients who will progress, discriminating patients who will respond to treatment from nonresponders, and developing algorithms for starting immunosuppression, antifibrotics, or both as first-line therapies.

Antifibrotic therapy in progressive pulmonary fibrosis: a review of recent advances

INTRODUCTION

Progressive pulmonary fibrosis (PPF) is a manifestation of a heterogenous group of underlying interstitial lung disease (ILD) diagnoses, defined as non-idiopathic pulmonary fibrosis (IPF) progressive fibrotic ILD meeting at least two of the following criteria in the previous 12 months: worsening respiratory symptoms, absolute decline in forced vital capacity (FVC) more than or equal to 5% and/or absolute decline in diffusing capacity for carbon monoxide (DLCO) more than or equal to 10% and/or radiological progression.

AREAS COVERED

The authors subjectively reviewed a synthesis of literature from PubMed to identify recent advances in the diagnosis and characterisation of PPF, treatment recommendations, and management challenges. This review provides a comprehensive summary of recent advances and highlights future directions for the diagnosis, management, and treatment of PPF.

EXPERT OPINION

Recent advances in defining the criteria for PPF diagnosis and licensing of treatment are likely to support further characterisation of the PPF patient population and improve our understanding of prevalence. The diagnosis of PPF remains challenging with the need for a specialised ILD multidisciplinary team (MDT) approach. The evidence base supports the use of immunomodulatory therapy to treat inflammatory ILDs and antifibrotic therapy where PPF develops. Treatment needs to be tailored to the specific underlying disease and determined on a case-by-case basis.

Interstitial Lung Disease: A Review

Importance

Interstitial lung disease (ILD) consists of a group of pulmonary disorders characterized by inflammation and/or fibrosis of the lung parenchyma associated with progressive dyspnea that frequently results in end-stage respiratory failure. In the US, ILD affects approximately 650 000 people and causes approximately 25 000 to 30 000 deaths per year.

Observations

The most common forms of ILD are idiopathic pulmonary fibrosis (IPF), which accounts for approximately one-third of all cases of ILD, hypersensitivity pneumonitis, accounting for 15% of ILD cases, and connective tissue disease (CTD), accounting for 25% of ILD cases. ILD typically presents with dyspnea on exertion. Approximately 30% of patients with ILD report cough. Thoracic computed tomography is approximately 91% sensitive and 71% specific for diagnosing subtypes of ILDs such as IPF. Physiologic assessment provides important prognostic information. A 5% decline in forced vital capacity (FVC) over 12 months is associated with an approximately 2-fold increase in mortality compared with no change in FVC. Antifibrotic therapy with nintedanib or pirfenidone slows annual FVC decline by approximately 44% to 57% in individuals with IPF, scleroderma associated ILD, and in those with progressive pulmonary fibrosis of any cause. For connective tissue disease-associated ILD, immunomodulatory therapy, such as tocilizumab, rituximab, and mycophenolate mofetil, may slow decline or even improve FVC at 12-month follow-up. Structured exercise therapy reduces symptoms and improves 6-minute walk test distance in individuals with dyspnea. Oxygen reduces symptoms and improves quality of life in individuals with ILD who desaturate below 88% on a 6-minute walk test. Lung transplant may improve symptoms and resolve respiratory failure in patients with end-stage ILD. After lung transplant, patients with ILD have a median survival of 5.2 to 6.7 years compared with a median survival of less than 2 years in patients with advanced ILD who do not undergo lung transplant. Up to 85% of individuals with end-stage fibrotic ILD develop pulmonary hypertension. In these patients, treatment with inhaled treprostinil improves walking distance and respiratory symptoms.

Conclusions and Relevance

Interstitial lung disease typically presents with dyspnea on exertion and can progress to respiratory failure. First-line therapy includes nintedanib or pirfenidone for IPF and mycophenolate mofetil for ILD due to connective tissue disease. Lung transplant should be considered for patients with advanced ILD. In patients with ILD, exercise training improves 6-minute walk test distance and quality of life.

Optimal clinical practice in IPF and PPF: Integrating the scientific ethos and clinical reasoning

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Radiological and histopathological features and treatment response by subtypes of interstitial pneumonia with autoimmune features: A prospective, multicentre cohort study

BACKGROUND

Patients with idiopathic interstitial pneumonia (IIP) have a favourable prognosis when they have interstitial pneumonia with autoimmune features (IPAF). However, precise IPAF-related findings from high-resolution computed tomography (HRCT) and lung histopathological specimens and the treatment response have not been fully determined. Therefore, this study was conducted to evaluate the relationship between findings on HRCT or lung histopathological specimens and the progression of interstitial pneumonia in patients with IPAF.

METHODS

This multicentre cohort study prospectively enrolled consecutive patients with IIP. At the diagnosis of IIP, we systematically evaluated 74 features suggestive of connective tissue diseases and followed them up. HRCT, lung specimens, serum antibodies, and the clinical course were also evaluated.

RESULTS

Among 222 patients with IIP, 26 (11.7%) fulfilled the IPAF criteria. During a median observation period of 36 months, patients with IPAF showed better survival than those without IPAF (p = 0.034). While histopathological findings were not related to IPAF, nonspecific interstitial pneumonia (NSIP) with organizing pneumonia (OP) overlap was the most prevalent HRCT pattern (p < 0.001) and the consolidation opacity was the most common radiological finding in IPAF (p = 0.017). Furthermore, in patients with IPAF, the diagnosis of COP or NSIP with OP overlap was associated with a higher increase in %FVC in 1 year than in those with idiopathic pulmonary fibrosis, NSIP, or unclassifiable IIP (p = 0.002).

CONCLUSIONS

This study shows the presence of consolidation opacity on HRCT and the diagnosis of COP or NSIP with OP overlap are associated with IPAF and its favourable treatment response in patients with IPAF.

Monitoring of Sarcoidosis

This article focuses on the monitoring of pulmonary sarcoidosis. The monitoring of sarcoidosis is, in part, focused on serial change in major organ involvement but also includes diagnostic re-evaluation and review of change in quality of life. Recent criteria for progression of fibrotic interstitial lung disease are adapted to pulmonary sarcoidosis. The frequency and nature of monitoring are discussed, integrating baseline risk stratification and strategic treatment goals. Individual variables used to identify changes in pulmonary disease severity are discussed with a focus on their flaws and the need for a multidimensional approach. Other key monitoring issues are covered briefly.

C-reactive protein as a candidate biomarker in fibrotic interstitial lung disease

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Pulmonary Fibrosis Stakeholder Summit: A Joint NHLBI, Three Lakes Foundation, and Pulmonary Fibrosis Foundation Workshop Report

Despite progress in elucidation of disease mechanisms, identification of risk factors, biomarker discovery, and the approval of two medications to slow lung function decline in idiopathic pulmonary fibrosis and one medication to slow lung function decline in progressive pulmonary fibrosis, pulmonary fibrosis remains a disease with a high morbidity and mortality. In recognition of the need to catalyze ongoing advances and collaboration in the field of pulmonary fibrosis, the NHLBI, the Three Lakes Foundation, and the Pulmonary Fibrosis Foundation hosted the Pulmonary Fibrosis Stakeholder Summit on November 8-9, 2022. This workshop was held virtually and was organized into three topic areas: 1) novel models and research tools to better study pulmonary fibrosis and uncover new therapies, 2) early disease risk factors and methods to improve diagnosis, and 3) innovative approaches toward clinical trial design for pulmonary fibrosis. In this workshop report, we summarize the content of the presentations and discussions, enumerating research opportunities for advancing our understanding of the pathogenesis, treatment, and outcomes of pulmonary fibrosis.

Risk factors for progression of pulmonary fibrosis: a single-centered, retrospective study

Objective

This study aimed to identify clinical characteristics associated with the prevalence of progressive pulmonary fibrosis (PPF) in interstitial lung disease (ILD) and to develop a prognostic nomogram model for clinical use.

Methods

In this single-centered, retrospective study, we enrolled ILD patients with relatively comprehensive clinical data and assessed the incidence of PPF within a year using collected demographics, laboratory data, high-resolution computed tomography (HRCT), and pulmonary function test (PFT) results. We used a training cohort of ILD patients to identify early predictors of PPF and then validated them in an internal validation cohort and subsets of ILD patients using a multivariable logistic regression analysis. A prognostic nomogram was formulated based on these predictors, and the accuracy and efficiency were evaluated using the area under the receiver operating characteristic curve (AUC), calibration plot, and decision curve analysis (DCA).

Results

Among the enrolled patients, 120 (39.09%) cases had connective tissue disease-associated interstitial lung disease (CTD-ILD), 115 (37.46%) had non-idiopathic pulmonary fibrosis idiopathic interstitial pneumonia (non-IPF IIP), and 35 (11.4%) had hypersensitivity pneumonitis (HP). Overall, 118 (38.4%) cases experienced pulmonary fibrosis progression. We found that baseline DLco% pred (OR 0.92; 95% CI, 8.93-0.95) was a protective factor for ILD progression, whereas combined pneumonia (OR 4.57; 95% CI, 1.24-18.43), modified Medical Research Council dyspnea score (mMRC) (OR 4.9; 95% CI, 2.8-9.5), and high-resolution computed tomography (HRCT) score (OR 1.22; 95% CI, 1.07-1.42) were independent risk factors for PPF. The AUC of the proposed nomogram in the development cohort was 0.96 (95% CI, 0.94, 0.98), and the calibration plot showed good agreement between the predicted and observed incidence of PPF (Hosmer-Lemeshow test: P = 0.86).

Conclusion

ILD patients with combined pneumonia, low baseline DLco% pred, high mMRC marks, and high HRCT scores were at higher risk of progression. This nomogram demonstrated good discrimination and calibration, indicating its potential utility for clinical practice.

A Deep Learning-Based Radiomic Classifier for Usual Interstitial Pneumonia

BACKGROUND

Because chest CT scan has largely supplanted surgical lung biopsy for diagnosing most cases of interstitial lung disease (ILD), tools to standardize CT scan interpretation are urgently needed.

RESEARCH QUESTION

Does a deep learning (DL)-based classifier for usual interstitial pneumonia (UIP) derived using CT scan features accurately discriminate radiologist-determined visual UIP?

STUDY DESIGN AND METHODS

A retrospective cohort study was performed. Chest CT scans acquired in individuals with and without ILD were drawn from a variety of public and private data sources. Using radiologist-determined visual UIP as ground truth, a convolutional neural network was used to learn discrete CT scan features of UIP, with outputs used to predict the likelihood of UIP using a linear support vector machine. Test performance characteristics were assessed in an independent performance cohort and multicenter ILD clinical cohort. Transplant-free survival was compared between UIP classification approaches using the Kaplan-Meier estimator and Cox proportional hazards regression.

RESULTS

A total of 2,907 chest CT scans were included in the training (n = 1,934), validation (n = 408), and performance (n = 565) data sets. The prevalence of radiologist-determined visual UIP was 12.4% and 37.1% in the performance and ILD clinical cohorts, respectively. The DL-based UIP classifier predicted visual UIP in the performance cohort with sensitivity and specificity of 93% and 86%, respectively, and in the multicenter ILD clinical cohort with 81% and 77%, respectively. DL-based and visual UIP classification similarly discriminated survival, and outcomes were consistent among cases with positive DL-based UIP classification irrespective of visual classification.

INTERPRETATION

A DL-based classifier for UIP demonstrated good test performance across a wide range of UIP prevalence and similarly discriminated survival when compared with radiologist-determined UIP. This automated tool could efficiently screen for UIP in patients undergoing chest CT scan and identify a high-risk phenotype among those with known ILD.

Thin-Section CT in the Categorization and Management of Pulmonary Fibrosis including Recently Defined Progressive Pulmonary Fibrosis

While idiopathic pulmonary fibrosis (IPF) is the most common type of fibrotic lung disease, there are numerous other causes of pulmonary fibrosis that are often characterized by lung injury and inflammation. Although often gradually progressive and responsive to immune modulation, some cases may progress rapidly with reduced survival rates (similar to IPF) and with imaging features that overlap with IPF, including usual interstitial pneumonia (UIP)-pattern disease characterized by peripheral and basilar predominant reticulation, honeycombing, and traction bronchiectasis or bronchiolectasis. Recently, the term progressive pulmonary fibrosis has been used to describe non-IPF lung disease that over the course of a year demonstrates clinical, physiologic, and/or radiologic progression and may be treated with antifibrotic therapy. As such, appropriate categorization of the patient with fibrosis has implications for therapy and prognosis and may be facilitated by considering the following categories: (a) radiologic UIP pattern and IPF diagnosis, (b) radiologic UIP pattern and non-IPF diagnosis, and (c) radiologic non-UIP pattern and non-IPF diagnosis. By noting increasing fibrosis, the radiologist contributes to the selection of patients in which therapy with antifibrotics can improve survival. As the radiologist may be first to identify developing fibrosis and overall progression, this article reviews imaging features of pulmonary fibrosis and their significance in non-IPF-pattern fibrosis, progressive pulmonary fibrosis, and implications for therapy. Keywords: Idiopathic Pulmonary Fibrosis, Progressive Pulmonary Fibrosis, Thin-Section CT, Usual Interstitial Pneumonia © RSNA, 2024.

Proteomic profiling of formalin-fixed paraffine-embedded tissue reveals key proteins related to lung dysfunction in idiopathic pulmonary fibrosis

Introduction

Idiopathic pulmonary fibrosis (IPF) severely affects the lung leading to aberrant deposition of extracellular matrix and parenchymal stiffness with progressive functional derangement. The limited availability of fresh tissues represents one of the major limitations to study the molecular profiling of IPF lung tissue. The primary aim of this study was to explore the proteomic profiling yield of archived formalin-fixed paraffin-embedded (FFPE) specimens of IPF lung tissues.

Methods

We further determined the protein expression according to respiratory functional decline at the time of biopsy. The total proteins isolated from 11 FFPE samples of IPF patients compared to 3 FFPE samples from a non-fibrotic lung defined as controls, were subjected to label-free quantitative proteomic analysis by liquid chromatography-mass spectrometry (LC-MS/MS) and resulted in the detection of about 400 proteins.

Results

After the pairwise comparison between controls and IPF, functional enrichment analysis identified differentially expressed proteins that were involved in extracellular matrix signaling pathways, focal adhesion and transforming growth factor β (TGF-β) signaling pathways strongly associated with IPF onset and progression. Five proteins were significantly over- expressed in the lung of IPF patients with either advanced disease stage (Stage II) or impaired pulmonary function (FVC<75, DLCO<55) compared to controls; these were lymphocyte cytosolic protein 1 (LCP1), peroxiredoxin-2 (PRDX2), transgelin 2 (TAGLN2), lumican (LUM) and mimecan (OGN) that might play a key role in the fibrogenic processes.

Discussion

Our work showed that the analysis of FFPE samples was able to identify key proteins that might be crucial for the IPF pathogenesis. These proteins are correlated with lung carcinogenesis or involved in the immune landscape of lung cancer, thus making possible common mechanisms between lung carcinogenesis and fibrosis progression, two pathological conditions at risk for each other in the real life.

Key learnings from the INBUILD trial in patients with progressive pulmonary fibrosis

In a patient with interstitial lung disease (ILD) of known or unknown etiology other than idiopathic pulmonary fibrosis (IPF), progressive pulmonary fibrosis (PPF) is defined by worsening lung fibrosis on high-resolution computed tomography (HRCT), decline in lung function, and/or deterioration in symptoms. The INBUILD trial involved 663 patients with PPF who were randomized to receive nintedanib or placebo. The median exposure to trial medication was approximately 19 months. The INBUILD trial provided valuable learnings about the course of PPF and the efficacy and safety of nintedanib. The relative effect of nintedanib on reducing the rate of forced vital capacity decline was consistent across subgroups based on ILD diagnosis, HRCT pattern, and disease severity at baseline, and between patients who were and were not taking glucocorticoids or disease-modifying anti-rheumatic drugs and/or glucocorticoids at baseline. The adverse events most frequently associated with nintedanib were gastrointestinal, particularly diarrhea, but nintedanib was discontinued in only a minority of cases. The results of the INBUILD trial highlight the importance of prompt detection and treatment of PPF and the utility of nintedanib as a treatment option.

Biogenesis and Function of circRNAs in Pulmonary Fibrosis

Pulmonary fibrosis is a class of fibrosing interstitial lung diseases caused by many pathogenic factors inside and outside the lung, with unknown mechanisms and without effective treatment. Therefore, a comprehensive understanding of the molecular mechanism implicated in pulmonary fibrosis pathogenesis is urgently needed to develop new and effective measures. Although circRNAs have been widely acknowledged as new contributors to the occurrence and development of diseases, only a small number of circRNAs have been functionally characterized in pulmonary fibrosis. Here, we systematically review the biogenesis and functions of circRNAs and focus on how circRNAs participate in pulmonary fibrogenesis by influencing various cell fates. Meanwhile, we analyze the current exploration of circRNAs as a diagnostic biomarker, vaccine, and therapeutic target in pulmonary fibrosis and objectively discuss the challenges of circRNA- based therapy for pulmonary fibrosis. We hope that the review of the implication of circRNAs will provide new insights into the development circRNA-based approaches to treat pulmonary fibrosis.

Radiologic approach and progressive exploration of connective tissue disease-related interstitial lung disease: meeting the curiosity of rheumatologists

Interstitial lung disease (ILD) is often observed in connective tissue diseases (CTDs), frequently in rheumatoid arthritis, systemic sclerosis, primary Sjögren's syndrome, and inflammatory myositis. Early detection of ILDs secondary to rheumatic diseases is important as timely initiation of proper management affects the prognosis. Among many imaging modalities, high-resuloution computed tomography (HRCT) serves the gold standard for finding early lung inflammatory and fibrotic changes as well as monitoring afterwards because of its superior spatial resolution. Additionally, lung ultrasound (LUS) and magnetic resonance imaging (MRI) are the rising free-radiation imaging tools that can get images of lungs of CTD-ILD. In this review article, we present the subtypes of ILD images found in each CTD acquired by HRCT as well as some images taken by LUS and MRI with comparative HRCT scans. It is expected that this discussion would be helpful in discussing recent advances in imaging modalities for CTD-ILD and raising critical points for diagnosis and tracing of the images from the perspective of rheumatologists.

One-year lung function decline in sarcoidosis

BACKGROUND

The definition of progressive pulmonary fibrosis is based on a 1-year lung function decline.

OBJECTIVES

To evaluate the epidemiology and clinical relevance of 1-year lung function decline in sarcoidosis.

METHODS

A retrospective observational study at a general sarcoidosis clinic.

RESULTS

Of the 198 patients, 42 (18.4 %) had a 1-year lung function decline (absolute 12-month decline in percentage predicted forced vital capacity [%FVC] of ≥5 % or percentage predicted diffusion capacity for carbon monoxide [%DLCO] of ≥10 %). A 1-year lung function decline was associated with a 2-year lung function decline (a relative 24-month decline in %FVC of ≥10 % or %DLCO of ≥15 %), which occurred in 13 (7.4 %) of the 175 patients with 24-month follow-up results. A 1-year lung function decline was not associated with survival; a 2-year lung function decline predicted mortality.

CONCLUSIONS

Compared with a 24-month decline, a 12-month decline in lung function did not predict worse survival in sarcoidosis.

Systemic sclerosis associated myopathy: how to treat

Purpose of review

Systemic sclerosis (SSc) and myositis are two different entities that may coexist as an overlap syndrome. Immunological biomarkers such as anti-PM/Scl or anti-Ku reinforce the syndrome. This review is focused on the treatment of different and characteristic manifestations of this syndrome.

Recent findings

Among the different phenotypes of muscle involvement in patients with SSc, the fibrotic pattern and the sporadic inclusion body myositis must be identified early to avoid a futile immunosuppressive treatment. Other forms such as dermatomyositis, non-specific myositis and immune-mediated necrotizing myopathy need to receive conventional immunosuppressive therapy considering that high dose of glucocorticoids may induce a scleroderma renal crisis in patients with SSc. Physicians must be aware of the existence of a "double trouble" association of hereditary myopathy with an autoimmune phenomenon. Several autoantibodies, mainly anti-PM/Scl and anti-Ku may help to define specific phenotypes with characteristic clinical manifestations that need a more specific therapy. Vasculopathy is one of the underlying mechanisms that link SSc and myositis. Recent advances in this topic are reviewed.

Summary

Current treatment of SSc associated myopathy must be tailored to specific organs involved. Identifying the specific clinical, pathological, and immunological phenotypes may help to take the correct therapeutic decisions.

Diagnosis of interstitial lung disease (ILD) secondary to systemic sclerosis (SSc) and rheumatoid arthritis (RA) and identification of 'progressive pulmonary fibrosis' using chest CT: a narrative review

Interstitial lung disease (ILD) is a frequent manifestation of connective tissue diseases (CTDs), with incidence and prevalence variously assessed in the literature but reported in up to 30% of patients, with higher frequency in rheumatoid arthritis (RA) and systemic sclerosis (SSc). Recent years have seen a growing interest in the pulmonary manifestations of ILD-CTDs, mainly due to the widening of the use of anti-fibrotic drugs initially introduced exclusively for IPF, and radiologists play a key role because the lung biopsy is very rarely used in these patients where the morphological assessment is essentially left to imaging and especially HRCT. In this narrative review we will discuss, from the radiologist's point of view, the most recent findings in the field of ILD secondary to SSc and RA, with a special focus about the progression of disease and in particular about the 'progressive pulmonary fibrosis' (PPF) phenotype, and we will try to address two main issues: How to predict a possible evolution and therefore a worse prognosis when diagnosing a new case of ILD-CTDs and how to assess the progression of an already diagnosed ILD-CTDs.

Clinical effect of progressive pulmonary fibrosis on patients with connective tissue disease-associated interstitial lung disease: a single center retrospective cohort study

The concept of progressive pulmonary fibrosis (PPF) has been introduced to predict the diverse prognosis of interstitial lung disease (ILD). However, the incidence and effect of PPF on outcomes in patients with connective tissue disease-associated interstitial lung disease (CTD-ILD) need to be elucidated. This study reviewed 197 patients with CTD-ILD. Symptomatic worsening, pulmonary function decline, and radiological deterioration were investigated to assess the fulfillment of PPF diagnostic criteria. Clinical outcomes, including mortality, were compared based on the presence or absence of PPF. The median follow-up duration was 17.4 months. The mean age of the patients was 64.0 years, and 60.9% were female. Among the underlying CTDs, rheumatoid arthritis (42.1%), inflammatory myositis (19.8%), and systemic sclerosis (13.2%) were the most common. Of the 197 patients, 37 (18.8%) met the diagnostic criteria for PPF during the follow-up period. Even after adjusting for other significant risk factors, PPF was independently associated with mortality [hazard ratio (HR) 3.856; 95% confidence interval (CI) 1.387-10.715; P = 0.010] and baseline albumin was marginally significantly associated with mortality (HR 0.549; CI 0.298-1.010; P = 0.054). The median survival was also significantly shorter in the PPF group than in the non-PPF group (72.3 ± 12.9 vs. 126.8 ± 15.5 months, P < 0.001). Baseline KL-6 ≥ 1000 (U/mL) was a significant risk factor for PPF (HR 2.885; CI 1.165-7.144; P = 0.022). In addition to increased mortality, the PPF group had significantly higher rates of respiratory-related hospitalizations, pneumonia, acute exacerbations, and weight loss than the non-PPF group. PPF is a significant prognostic indicator in patients with CTD-ILD. Thus, healthcare professionals should know that patients with CTD-ILD are at risk of PPF.

Combination of BAL and Computed Tomography Differentiates Progressive and Non-progressive Fibrotic Lung Diseases

Rationale: Identifying patients with pulmonary fibrosis (PF) at risk of progression can guide management. Objectives: To explore the utility of combining baseline BAL and computed tomography (CT) in differentiating progressive and nonprogressive PF. Methods: The derivation cohort consisted of incident cases of PF for which BAL was performed as part of a diagnostic workup. A validation cohort was prospectively recruited with identical inclusion criteria. Baseline thoracic CT scans were scored for the extent of fibrosis and usual interstitial pneumonia (UIP) pattern. The BAL lymphocyte proportion was recorded. Annualized FVC decrease of >10% or death within 1 year was used to define disease progression. Multivariable logistic regression identified the determinants of the outcome. The optimum binary thresholds (maximal Wilcoxon rank statistic) at which the extent of fibrosis on CT and the BAL lymphocyte proportion could distinguish disease progression were identified. Measurements and Main Results: BAL lymphocyte proportion, UIP pattern, and fibrosis extent were significantly and independently associated with disease progression in the derivation cohort (n = 240). Binary thresholds for increased BAL lymphocyte proportion and extensive fibrosis were identified as 25% and 20%, respectively. An increased BAL lymphocyte proportion was rare in patients with a UIP pattern (8 of 135; 5.9%) or with extensive fibrosis (7 of 144; 4.9%). In the validation cohort (n = 290), an increased BAL lymphocyte proportion was associated with a significantly lower probability of disease progression in patients with nonextensive fibrosis or a non-UIP pattern. Conclusions: BAL lymphocytosis is rare in patients with extensive fibrosis or a UIP pattern on CT. In patients without a UIP pattern or with limited fibrosis, a BAL lymphocyte proportion of ⩾25% was associated with a lower likelihood of progression.

Triptolide attenuates pulmonary fibrosis by inhibiting fibrotic extracellular matrix remodeling mediated by MMPs/LOX/integrin

BACKGROUND

Fibrotic extracellular matrix (ECM) remodeling characterized different types of pulmonary fibrosis, and its regulation could be a potential shared treatment strategy for pulmonary fibrosis.

PURPOSE

We aimed to investigate the effect of triptolide on pulmonary fibrosis through the inhibition of several important aspects of fibrotic ECM remodeling.

METHODS

Bleomycin-induced pulmonary fibrosis mice and TGF-β1-induced primary lung fibroblasts were used. The effect of triptolide on pulmonary fibrosis was detected using histopathology, immunostaining, RT-qPCR, western blotting, ELISA, and protein activity assay.

RESULTS

Triptolide significantly alleviated bleomycin-induced pulmonary fibrosis in mice. It inhibited the expression of fibrotic genes α-SMA, collagen I, fibronectin, and vimentin and blocked the TGF-β-SMAD signaling pathway both in vivo and in vitro. In addition, triptolide regulated the expression and activity of MMPs during fibrosis. Interestingly, it suppressed the expression of lysyl oxidase, which was responsible for matrix cross-linking and elevated ECM stiffness. Furthermore, triptolide blocked the biomechanical stress transduction pathway integrin-β1-FAK-YAP signaling and attenuated the pro-fibrotic feedback of fibrotic ECM on fibroblasts via integrin inhibition.

CONCLUSION

These findings show that triptolide prevents the key linkages of fibrotic ECM remodeling, including deposition, degradation, cross-linking, and pro-fibrotic feedback and, therefore, has potential therapeutic value for pulmonary fibrosis.

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.

Exploring computer-based imaging analysis in interstitial lung disease: opportunities and challenges

The advent of quantitative computed tomography (QCT) and artificial intelligence (AI) using high-resolution computed tomography data has revolutionised the way interstitial diseases are studied. These quantitative methods provide more accurate and precise results compared to prior semiquantitative methods, which were limited by human error such as interobserver disagreement or low reproducibility. The integration of QCT and AI and the development of digital biomarkers has facilitated not only diagnosis but also prognostication and prediction of disease behaviour, not just in idiopathic pulmonary fibrosis in which they were initially studied, but also in other fibrotic lung diseases. These tools provide reproducible, objective prognostic information which may facilitate clinical decision-making. However, despite the benefits of QCT and AI, there are still obstacles that need to be addressed. Important issues include optimal data management, data sharing and maintenance of data privacy. In addition, the development of explainable AI will be essential to develop trust within the medical community and facilitate implementation in routine clinical practice.

Treatable traits: a comprehensive precision medicine approach in interstitial lung disease

Interstitial lung disease (ILD) is a diverse group of inflammatory and fibrotic lung conditions causing significant morbidity and mortality. A multitude of factors beyond the lungs influence symptoms, health-related quality of life, disease progression and survival in patients with ILD. Despite an increasing emphasis on multidisciplinary management in ILD, the absence of a framework for assessment and delivery of comprehensive patient care poses challenges in clinical practice. The treatable traits approach is a precision medicine care model that operates on the premise of individualised multidimensional assessment for distinct traits that can be targeted by specific interventions. The potential utility of this approach has been described in airway diseases, but has not been adequately considered in ILD. Given the similar disease heterogeneity and complexity between ILD and airway diseases, we explore the concept and potential application of the treatable traits approach in ILD. A framework of aetiological, pulmonary, extrapulmonary and behavioural and lifestyle treatable traits relevant to clinical care and outcomes for patients with ILD is proposed. We further describe key research directions to evaluate the application of the treatable traits approach towards advancing patient care and health outcomes in ILD.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Idiopathic Pulmonary Fibrosis and Progressive Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), a common interstitial lung disease (ILD), is a chronic, progressive fibrosing interstitial pneumonia, with an unknown cause. IPF has been linked to several genetic and environmental risk factors. Disease progression is common and associated with worse outcomes. Management often encompasses pharmacotherapy, supportive interventions, addressing comorbidities when present, and treating hypoxia with ambulatory O2. Consideration for antifibrotic therapy and lung transplantation evaluation should occur early. Patients with ILD other than IPF, and who have radiological evidence of pulmonary fibrosis, may have progressive pulmonary fibrosis.

The influence of immortal time bias in observational studies examining associations of antifibrotic therapy with survival in idiopathic pulmonary fibrosis: A simulation study

Background

Immortal time bias (ITB) has been overlooked in idiopathic pulmonary fibrosis (IPF). We aimed to identify the presence of ITB in observational studies examining associations between antifibrotic therapy and survival in patients with IPF and illustrate how ITB may affect effect size estimates of those associations.

Methods

Immortal time bias was identified in observational studies using the ITB Study Assessment Checklist. We used a simulation study to illustrate how ITB may affect effect size estimates of antifibrotic therapy on survival in patients with IPF based on four statistical techniques including time-fixed, exclusion, time-dependent and landmark methods.

Results

Of the 16 included IPF studies, ITB was detected in 14 studies, while there were insufficient data for assessment in two others. Our simulation study showed that use of time-fixed [hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.47-0.64] and exclusion methods (HR 0.79, 95% CI 0.67-0.92) overestimated the effectiveness of antifibrotic therapy on survival in simulated subjects with IPF, in comparison of the time-dependent method (HR 0.93, 95% CI 0.79-1.09). The influence of ITB was mitigated using the 1 year landmark method (HR 0.69, 95% CI 0.58-0.81), compared to the time-fixed method.

Conclusion

The effectiveness of antifibrotic therapy on survival in IPF can be overestimated in observational studies, if ITB is mishandled. This study adds to the evidence for addressing the influence of ITB in IPF and provides several recommendations to minimize ITB. Identifying the presence of ITB should be routinely considered in future IPF studies, with the time-dependent method being an optimal approach to minimize ITB.

Genetics in Idiopathic Pulmonary Fibrosis: A Clinical Perspective

BACKGROUND

Unraveling the genetic background in a significant proportion of patients with both sporadic and familial IPF provided new insights into the pathogenic pathways of pulmonary fibrosis.

AIM

The aim of the present study is to overview the clinical significance of genetics in IPF.

PERSPECTIVE

It is fascinating to realize the so-far underestimated but dynamically increasing impact that genetics has on aspects related to the pathophysiology, accurate and early diagnosis, and treatment and prevention of this devastating disease. Genetics in IPF have contributed as no other in unchaining the disease from the dogma of a "a sporadic entity of the elderly, limited to the lungs" and allowed all scientists, but mostly clinicians, all over the world to consider its many aspects and "faces" in all age groups, including its co-existence with several extra pulmonary conditions from cutaneous albinism to bone-marrow and liver failure.

CONCLUSION

By providing additional evidence for unsuspected characteristics such as immunodeficiency, impaired mucus, and surfactant and telomere maintenance that very often co-exist through the interaction of common and rare genetic variants in the same patient, genetics have created a generous and pluralistic yet unifying platform that could lead to the understanding of the injurious and pro-fibrotic effects of many seemingly unrelated extrinsic and intrinsic offending factors. The same platform constantly instructs us about our limitations as well as about the heritability, the knowledge and the wisdom that is still missing.

Clinical, imaging, and blood biomarkers to assess 1-year progression risk in fibrotic interstitial lung diseases-Development and validation of the honeycombing, traction bronchiectasis, and monocyte (HTM)-score

Introduction

Progression of fibrotic interstitial lung disease (ILD) leads to irreversible loss of lung function and increased mortality. Based on an institutional ILD registry, we aimed to evaluate biomarkers derived from baseline patient characteristics, computed tomography (CT), and peripheral blood for prognosis of disease progression in fibrotic ILD patients.

Methods

Of 209 subsequent ILD-board patients enregistered, 142 had complete follow-up information and were classified fibrotic ILD as defined by presence of reticulation or honeycombing using a standardized semi-quantitative CT evaluation, adding up typical ILD findings in 0-6 defined lung fields. Progression at 1 year was defined as relative loss of ≥10% in forced vital capacity, of ≥15% in diffusion capacity for carbon monoxide, death, or lung transplant. Two-thirds of the patients were randomly assigned to a derivation cohort evaluated for the impact of age, sex, baseline lung function, CT finding scores, and blood biomarkers on disease progression. Significant variables were included into a regression model, its results were used to derive a progression-risk score which was then applied to the validation cohort.

Results

In the derivation cohort, age, monocyte count ≥0.65 G/L, honeycombing and traction bronchiectasis extent had significant impact. Multivariate analyses revealed the variables monocyte count ≥0.65 G/L (1 point) and combined honeycombing or traction bronchiectasis score [0 vs. 1-4 (1 point) vs. 5-6 lung fields (2 points)] as significant, so these were used for score development. In the derivation cohort, resulting scores of 0, 1, 2, and 3 accounted for 1-year progression rates of 20, 25, 46.9, and 88.9%, respectively. Similarly, in the validation cohort, progression at 1 year occurred in 0, 23.8, 53.9, and 62.5%, respectively. A score ≥2 showed 70.6% sensitivity and 67.9% specificity, receiver operating characteristic analysis for the scoring model had an area under the curve of 71.7%.

Conclusion

The extent of honeycombing and traction bronchiectasis, as well as elevated blood monocyte count predicted progression within 1 year in fibrotic ILD patients.