Evaluating disease severity in idiopathic pulmonary fibrosis

Nintedanib loaded iron (III) chelated melanin nanoparticles as an MRI-visible antifibrotic drug delivery system

Idiopathic pulmonary fibrosis (IPF) is a fatal, progressive lung disease characterized by extensive scarring and thickening of lung tissue that leads to respiratory failure. Early and accurate diagnosis is crucial for monitoring disease progression and assessing therapeutic efficacy. While imaging modalities such as radiological X-rays and high-resolution computed tomography (HRCT) are commonly employed, magnetic resonance imaging (MRI) offers significant advantages, including superior soft tissue contrast and the absence of ionizing radiation. However, in lung MRIs are hindered by short transverse relaxation times, low proton density, and motion artifacts which is addressed herein by developing theranostic platform combining MRI imaging with targeted drug delivery using melanin nanoparticles conjugated with nintedanib (MNP-NIN). Chelation with ferric ions (MNP-NIN-Fe³⁺) enhanced MRI visibility enabling non-invasive imaging and drug tracking. MNP-NIN and MNP-NIN-Fe³ ⁺ nanoparticles were built with mean diameters of 189 ± 44 nm and 182 ± 35 nm, respectively and demonstrating successful NIN conjugation. Controlled NIN release followed zero-order kinetics over 36 days. MNP conjugation reduced cytotoxicity in BEAS-2B and A549 cells improving the drug's safety. MRI experiments conducted with a 7.0 T animal scanner demonstrated enhanced imaging contrast with MNP-NIN-Fe solutions compared to saline underscoring their potential for localized visualization and tracking within lung tissues. By integrating MRI diagnostics and targeted drug delivery, the MNP-NIN-Fe³ ⁺ system offers a promising solution to overcome current challenges in IPF management. This theranostic platform addresses the limitations of conventional imaging techniques while providing an innovative strategy for reducing drug-related systemic side effects and improving therapeutic efficacy.

The role of digital health in respiratory diseases management: a narrative review of recent literature

This review provides a detailed overview of how digital health can be utilized in the management of Interstitial Lung Disease (ILD), and Chronic Obstructive Pulmonary Disease (COPD). ILD encompasses a diverse range of lung disorders characterized by inflammation and scarring of lung tissue, leading to restrictive lung physiology and impaired gas exchange, with symptoms including progressive dyspnoea, cough, and hypoxia. COPD which ranks as the third leading cause of death globally, is characterized by chronic lung inflammation causing irreversible airflow obstruction, recurrent exacerbations. While recent advances in digital health have shown promise, predicting disease progression in patients with ILD and exacerbation in patients with COPD remains challenging. This review explores the role of digital health in managing ILD and COPD, particularly focusing on telehealth and digital health technologies. Telehealth, defined broadly as the use of electronic information and telecommunications technologies in healthcare, has become increasingly relevant, especially during the COVID-19 pandemic. This review examines the role of digital health technologies in the management of ILD and COPD, with particular focus on telemedicine, and digital health tools. Remote monitoring technologies, including home spirometry and wearable devices, have demonstrated feasibility in managing respiratory diseases. However, challenges such as evidence, data reliability, varying adherence, education, and the high costs of data collection and lack of qualified clinicians present barriers for many national health systems.

Development and validation of a predictive equation for resting energy expenditure in Japanese patients with interstitial lung disease

BACKGROUND AND AIMS

This study developed a prediction equation for resting energy expenditure (REE) in patients with interstitial lung disease (ILD) using indirect calorimetry and examined the errors in the prediction equation.

METHODS

This study consisted of two key phases: Study 1 focused on developing the prediction equation for REE, whereas Study 2 evaluated the accuracy of this equation through validation and error analysis. In Study 1, REE was measured, and a regression model equation was created to predict REE using multiple regression analysis, with measured REE (mREE) as the dependent variable. In Study 2, a Bland-Altman analysis was conducted to examine the phylogenetic error and agreement between predicted REE (pREE) calculated from the prediction equations developed in Study 1 and mREE.

RESULTS

In Study 1, mREE was significantly associated with fat-free mass (FFM), and the prediction equation for REE was 456.988 + 22.539 × FFM. The addition error (0.4 ± 166.1, 95% confidence interval (CI): -55.8 to 56.6, P = 0.988) and proportional error (r = 0.223, P = 0.191) between mREE and pREE were not significantly different, with an agreement of 69.4%.

CONCLUSIONS

The mREE prediction equation developed in this study showed no systematic errors and exhibited higher agreement compared with existing prediction equations. The prediction equation for REE specific to patients with ILD obtained in this study has the potential for clinical application.

Revised Precapillary Pulmonary Hypertension Criteria and Their Prognostic Value in IPF Transplant Waitlist Survival

Idiopathic pulmonary fibrosis (IPF) is a leading indication for lung transplantation. Pulmonary hypertension (PH), a common comorbidity in IPF, has gained renewed attention following the updated ESC/ERS guidelines, which redefine diagnostic thresholds for PH. This study evaluates the impact of the revised PH criteria on transplant waitlist outcomes among IPF patients. Specifically, we assessed the prevalence of PH under the new guidelines and its association with waitlist survival. We conducted a retrospective analysis using the OPTN/SRTR database, including 14,156 IPF candidates listed for lung transplantation. Survival analyses were performed using Kaplan-Meier and multivariate models to examine the influence of revised mPAP and PVR thresholds on waitlist mortality. The prevalence of PH, defined by the revised criteria, was significantly higher compared to the prior definition. Kaplan-Meier analysis demonstrated worse waitlist survival for patients with PH under both diagnostic thresholds. However, multivariate analysis revealed that mPAP and PVR thresholds were not independently predictive of mortality. Instead, clinical parameters, including 6MWD, functional status, BMI, FVC, PaCO2, and double lung transplant preference, were significant predictors of waitlist mortality. In conclusion, while the revised PH diagnostic criteria increase PH prevalence in IPF patients, their independent prognostic utility for waitlist survival is limited. This national transplant database study underscores the importance of comprehensive clinical evaluation and timely referral for transplantation in managing IPF with PH.

Prevalence, Clinical Features, and Outcomes of Young Patients with Idiopathic Pulmonary Fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) can occur at any age; however, studies on younger IPF patients are scarce because it primarily affects the elderly. This study aimed to investigate the clinical features and outcomes of younger IPF patients.

METHODS

We analyzed the National Korean Health Insurance Review and Assessment Service (HIRA) database from 2015 to 2021. Patients with IPF were identified using the International Classification of Diseases 10th Revision (ICD-10) codes and the Rare Intractable Diseases codes and were categorized into three age groups: <50, ≥50 and <65, and ≥65 years. The risk of acute exacerbation (AE) and mortality was analyzed.

RESULTS

Among 4,243 patients with IPF, 91 were under 50. These younger patients, who were predominantly female, exhibited less comorbidities and received more systemic steroids, whereas older group received more pirfenidone. Although AE risk increased with age, it was not statistically significant. Mortality and lung transplantation risks increased notably with age from the <50 group to the ≥50 and <65 group (hazard ratio [HR]: 1.52, 95% confidence interval [CI]: 0.93-2.49) and the ≥65 group (HR: 2.44, 95% CI: 1.51-3.93). These risks were influenced by factors such as age, comorbidities, previous AEs, and steroid use. Conversely, pirfenidone treatment reduced the risk.

CONCLUSION

While younger IPF patients had a lower risk of mortality and lung transplantation, with no significant differences in the risk of AEs, they were less likely to receive antifibrotic therapy and more often treated with steroids, which may affect outcomes. Early, targeted treatment strategies, including antifibrotic use, are crucial for improving their prognosis.

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) can occur at any age; however, studies on younger IPF patients are scarce because it primarily affects the elderly. This study aimed to investigate the clinical features and outcomes of younger IPF patients.

METHODS

We analyzed the National Korean Health Insurance Review and Assessment Service (HIRA) database from 2015 to 2021. Patients with IPF were identified using the International Classification of Diseases 10th Revision (ICD-10) codes and the Rare Intractable Diseases codes and were categorized into three age groups: <50, ≥50 and <65, and ≥65 years. The risk of acute exacerbation (AE) and mortality was analyzed.

RESULTS

Among 4,243 patients with IPF, 91 were under 50. These younger patients, who were predominantly female, exhibited less comorbidities and received more systemic steroids, whereas older group received more pirfenidone. Although AE risk increased with age, it was not statistically significant. Mortality and lung transplantation risks increased notably with age from the <50 group to the ≥50 and <65 group (hazard ratio [HR]: 1.52, 95% confidence interval [CI]: 0.93-2.49) and the ≥65 group (HR: 2.44, 95% CI: 1.51-3.93). These risks were influenced by factors such as age, comorbidities, previous AEs, and steroid use. Conversely, pirfenidone treatment reduced the risk.

CONCLUSION

While younger IPF patients had a lower risk of mortality and lung transplantation, with no significant differences in the risk of AEs, they were less likely to receive antifibrotic therapy and more often treated with steroids, which may affect outcomes. Early, targeted treatment strategies, including antifibrotic use, are crucial for improving their prognosis.

Treatment patterns and patient journey in progressive pulmonary fibrosis: a cross-sectional survey

BACKGROUND

For patients with interstitial lung diseases (ILDs) presenting with a progressive pulmonary fibrosis (PPF) phenotype, current knowledge of disease characteristics at diagnosis, patient journey, and treatment is limited. This study aimed to describe demographics and clinical experiences of patients presenting with PPF in a European real-world setting.

METHODS

Data were analysed from the Adelphi Real World PPF-ILD Disease Specific Programme™, a cross-sectional survey of pulmonologists and rheumatologists in five European countries (France, Germany, Italy, Spain, United Kingdom) and internal medicine specialists (France) from April to October 2022. Physicians provided data for up to 12 consecutive patients with physician-confirmed ILD with a progressive phenotype other than idiopathic pulmonary fibrosis. Analyses were descriptive.

RESULTS

Overall, 265 physicians reported on 1,335 patients. Mean (standard deviation) age at survey date was 60.4 (11.6) years, 91.2% were white, 58.1% female, 44.0% non-smokers. Most patients (63.3%) first consulted a primary care physician. There was a mean delay of 7.8 (22.7) months between first ILD symptom and healthcare professional visit, and another 7.7 (12.8) months to ILD diagnosis. At survey date, 47.7% of patients had physician-reported moderate ILD, 42.3% had mild ILD and 10.0% had severe ILD. Disease progression was reported in the 12 months prior to the survey for 19.5% of patients; of these, progression was based on worsening symptom in 27.3% and lung function decline in 25.8%. For patients experiencing symptoms prior to ILD diagnosis (72.8%), the most common symptoms were dyspnoea on exertion (80.5%) and cough (57.8%). Overall, 17.4% of patients were misdiagnosed prior to ILD diagnosis, with chronic obstructive pulmonary disease suspected in 39.2% of them. The most frequent comorbidities were anxiety (16.9%) and gastroesophageal reflux (15.5%). Although 77.8% of patients were receiving treatment for ILD at survey date, 15.6% of patients had never been prescribed treatment for ILD.

CONCLUSIONS

This real-world study expands our understanding of patients, diagnostic delays and treatment gaps experienced by patients diagnosed with PPF in Europe. There was a mean delay of 15.5 months between first ILD symptoms and ILD diagnosis. Given the progressive nature of PPF, diagnostic delay may lead to poor outcomes, including shorter survival.

TRIAL REGISTRATION

N/a.

Current challenges in the diagnosis and management of idiopathic pulmonary fibrosis in Japan

Idiopathic pulmonary fibrosis (IPF) is the archetypal interstitial lung disease. It is a chronic progressive condition that is challenging to manage as the clinical course of the disease is often difficult to predict. The prevalence of IPF is rising globally and in Japan, where it is estimated to affect 27 individuals per 100,000 of the population. Greater patient numbers and the poor prognosis associated with IPF diagnosis mean that there is a growing need for disease management approaches that can slow or even reverse disease progression and improve survival. Considerable progress has been made in recent years, with the approval of two antifibrotic therapies for IPF (pirfenidone and nintedanib), the availability of Japanese treatment guidelines, and the creation of global and Japanese disease registries. Despite this, significant unmet needs remain with respect to the diagnosis, treatment, and management of this complex disease. Each of these challenges will be discussed in this review, including making a timely and differential diagnosis of IPF, uptake and adherence to antifibrotic therapy, patient access to pulmonary rehabilitation, lung transplantation and palliative care, and optimal strategies for monitoring and staging disease progression, with a particular focus on the status in Japan. In addition, the review will reflect upon how ongoing research, clinical trials of novel therapies, and technologic advancements (including artificial intelligence, biomarkers, and genomic classification) may help address these challenges in the future.

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.

Prognostic implication of 1-year decline in diffusing capacity in newly diagnosed idiopathic pulmonary fibrosis

The progression of idiopathic pulmonary fibrosis (IPF) is assessed through serial monitoring of forced vital capacity (FVC). Currently, data regarding the clinical significance of longitudinal changes in diffusing capacity for carbon monoxide (DLCO) is lacking. We investigated the prognostic implications of a 1-year decline in DLCO in 319 patients newly diagnosed with IPF at a tertiary hospital between January 2010 and December 2020. Changes in FVC and DLCO over the first year after the initial diagnosis were reviewed; a decline in FVC ≥ 5% and DLCO ≥ 10% predicted were considered significant changes. During the first year after diagnosis, a significant decline in FVC and DLCO was observed in 101 (31.7%) and 64 (20.1%) patients, respectively. Multivariable analysis showed that a 1-year decline in FVC ≥ 5% predicted (aHR 2.74, 95% CI 1.88-4.00) and 1-year decline in DLCO ≥ 10% predicted (aHR 2.31, 95% CI 1.47-3.62) were independently associated with a higher risk of subsequent mortality. The prognostic impact of a decline in DLCO remained significant regardless of changes in FVC, presence of emphysema, or radiographic indications of pulmonary hypertension. Therefore, serial monitoring of DLCO should be recommended because it may offer additional prognostic information compared with monitoring of FVC alone.

Association between body fat decrease during the first year after diagnosis and the prognosis of idiopathic pulmonary fibrosis: CT-based body composition analysis

BACKGROUND

The prognostic role of changes in body fat in patients with idiopathic pulmonary fibrosis (IPF) remains underexplored. We investigated the association between changes in body fat during the first year post-diagnosis and outcomes in patients with IPF.

METHODS

This single-center, retrospective study included IPF patients with chest CT scan and pulmonary function test (PFT) at diagnosis and a one-year follow-up between January 2010 and December 2020. The fat area (cm2, sum of subcutaneous and visceral fat) and muscle area (cm2) at the T12-L1 level were obtained from chest CT images using a fully automatic deep learning-based software. Changes in the body composition were dichotomized using thresholds dividing the lowest quartile and others, respectively (fat area: -52.3 cm2, muscle area: -7.4 cm2). Multivariable Cox regression analyses adjusted for PFT result and IPF extent on CT images and the log-rank test were performed to assess the association between the fat area change during the first year post-diagnosis and the composite outcome of death or lung transplantation.

RESULTS

In total, 307 IPF patients (69.3 ± 8.1 years; 238 men) were included. During the first year post-diagnosis, fat area, muscle area, and body mass index (BMI) changed by -15.4 cm2, -1 cm2, and - 0.4 kg/m2, respectively. During a median follow-up of 47 months, 146 patients had the composite outcome (47.6%). In Cox regression analyses, a change in the fat area < -52.3 cm2 was associated with composite outcome incidence in models adjusted with baseline clinical variables (hazard ratio [HR], 1.566, P = .022; HR, 1.503, P = .036 in a model including gender, age, and physiology [GAP] index). This prognostic value was consistent when adjusted with one-year changes in clinical variables (HR, 1.495; P = .030). However, the change in BMI during the first year was not a significant prognostic factor (P = .941). Patients with a change in fat area exceeding this threshold experienced the composite outcome more frequently than their counterparts (58.4% vs. 43.9%; P = .007).

CONCLUSION

A ≥ 52.3 cm2 decrease in fat area, automatically measured using deep learning technique, at T12-L1 in one year post-diagnosis was an independent poor prognostic factor in IPF patients.

Betanin protects against bleomycin-induced pulmonary fibrosis by regulating the NLRP3/IL-1β/TGF-β1 pathway-mediated epithelial-to-mesenchymal transition

Idiopathic pulmonary fibrosis (IPF) is a life-threatening disease that leads to dyspnea and progressive loss of lung function. This study aimed to investigate the protective effect of betanin (BET), the major pigment in red beetroot, on pulmonary fibrosis induced by bleomycin (BLM) in rats and to assess the underlying mechanisms. In this view, total and differential cell counts and LDH activity in bronchoalveolar lavage fluid were estimated. Furthermore, MDA and GSH contents in the lungs were colorimetrically measured, while hydroxyproline, NLRP3, ASC, caspase-1, TGF-β1, and vimentin levels in lung tissue were evaluated using the ELISA technique. Moreover, IL-1β, E-cadherin, and α-SMA expressions were analyzed by immunostaining of lung specimens. BET treatment protects against pulmonary fibrosis as indicated by the reduction in total and differential cell counts, LDH activity, hydroxyproline, NLRP3, ASC, caspase-1, IL-1β, and TGF-β1 levels. MDA content was also decreased following BET administration, while GSH content was elevated. Additionally, BET suppressed the EMT process as evidenced by an increase in E-cadherin expression besides the reduction in vimentin and α-SMA expressions. To conclude, these results revealed the protective effect of BET against pulmonary fibrosis that might be attributed to the attenuation of the NLRP3/IL-1β/TGF-β1 signaling pathway and EMT process.

The effect of CALIPER-derived parameters for idiopathic pulmonary fibrosis in predicting prognosis, progression, and mortality: a systematic review

BACKGROUND

High-resolution computed tomography (HRCT), as the main tool for monitoring idiopathic pulmonary fibrosis (IPF), is characterized by subjective variability among radiologists and insensitivity to subtle changes. Recently, a few studies have aimed to decrease subjective bias by assessing the severity of IPF using computer software, i.e., Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER). However, these studies had diverse research directions. In this review, we systematically assess the effect of CALIPER in the management of IPF.

METHODS

A systematic review was conducted through a search of published studies in PubMed, Web of Science, Cochrane, Embase, Scopus, and CNKI databases from database inception through February 28, 2022. The methodological quality would be evaluated by using Methodological Index for Non-Randomized Studies (MINORS). Narrative synthesis summarized findings by participant characteristics, study design, and associations with outcomes.

RESULTS

Ten studies were included. They evaluated the relationship between CALIPER-derived parameters and pulmonary function test (PFT) and mortality. CALIPER-derived parameters showed a significant correlation with PFT and mortality. Two studies reported that CALIPER could be used to stratify outcomes.

CONCLUSION

CALIPER-derived parameters can be used to evaluate prognosis and mortality. CALIPER-derived parameters combined with composite physiologic index (CPI) or Gender-Age-Physiology (GAP) could help clinicians implement targeted management by refining prognostic stratification. However, research has been constrained by small number of retrospective investigations and sample sizes. Therefore, it is essential to design prospective controlled studies and establish the staging system by CALIPER-derived parameters and combining them with CPI, FVC, or GAP.

CLINICAL RELEVANCE STATEMENT

It is beneficial for clinic to provide objective, sensitive, and accurate indicators of disease progression. It also helps the clinic to develop individualized treatment plans based on the stage of disease progression and provides evaluation of efficacy in drug trials.

KEY POINTS

• Computer-Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) is a quantitative CT analysis software that can be used to evaluate the progression of disease on CT. • The CALIPER-derived vessel-related structure shows great performance in the management of idiopathic pulmonary fibrosis. • CALIPER-derived parameters combined with composite physiologic index or Gender-Age-Physiology can be used to refine prognostic stratification.

Efficacy and Safety of Pirfenidone in Advanced Versus Non-Advanced Idiopathic Pulmonary Fibrosis: Post-Hoc Analysis of Six Clinical Studies

INTRODUCTION

In the European Union (EU), the indication for the antifibrotic pirfenidone prior to April 2023 did not include patients with advanced idiopathic pulmonary fibrosis (IPF). This analysis compared the efficacy and safety of pirfenidone in advanced IPF versus non-advanced IPF.

METHODS

Data were included from the following studies of pirfenidone: ASCEND (NCT01366209); CAPACITY (004 [NCT00287716] and 006 [NCT00287729]); RECAP (NCT00662038; advanced IPF defined as percent predicted forced vital capacity [%FVC] < 50% and/or percent predicted carbon monoxide diffusing capacity [%DLco] < 35% at baseline); PASSPORT (NCT02699879; advanced IPF defined as baseline %FVC < 50%); and SP-IPF (NCT02951429; patients with advanced IPF [defined as %DLco ≤ 40% at screening] at risk of group 3 pulmonary hypertension).

RESULTS

In the pooled ASCEND/CAPACITY studies, the annual mean rate of FVC decline from baseline to Week 52 was significantly lower for pirfenidone versus placebo in advanced (p = 0.0035) and non-advanced IPF (p = 0.0001). Rate of all-cause mortality over 52 weeks was numerically lower for pirfenidone versus placebo in advanced and non-advanced IPF. In RECAP, the mean annual rate of FVC decline from baseline to Week 180 of pirfenidone treatment was similar in patients with advanced (- 141.5 mL) and non-advanced IPF (- 153.5 mL). In SP-IPF, the mean annual rate of FVC decline and rate of all-cause mortality from baseline to Week 52 in patients treated with placebo + pirfenidone were - 93.0 mL and 20.2%, respectively. No new safety signals were identified, and the safety profile of pirfenidone in patients with advanced IPF was generally consistent with that of non-advanced IPF.

CONCLUSIONS

These results highlight the benefit of pirfenidone treatment in patients with advanced and non-advanced IPF. As such, the indication for pirfenidone in the EU has now been updated to include the treatment of adult patients with advanced IPF.

TRIAL REGISTRATIONS

ASCEND (NCT01366209), CAPACITY 004 (NCT00287716), CAPACITY 006 (NCT00287729), RECAP (NCT00662038), PASSPORT (NCT02699879), and SP-IPF (NCT02951429).

A role for the terminal C5-C9 complement pathway in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by damage to the alveolar epithelium, leading to fibrosis and excessive accumulation of extracellular matrix in the interstitium of the lung. In the present study we performed high-resolution proteomic profiling of bronchoalveolar lavage (BAL) from IPF patients and controls, and found that the complement pathway was highly upregulated in IPF. The proteins C5, C6, C7, C8, and C9, all of which are part of the complement end product, TCC, were all upregulated. We also found that TCC levels were increased in plasma among IPF patients compared to controls, after adjustment for age, sex and BMI [mean (SD) 0.62 (0.24) vs. 0.33 (0.10), p = 0.031]. These findings suggest a role for the complement system in the pathogenesis of IPF.

Effects of short-term air pollution exposure on symptoms development in the course of idiopathic pulmonary fibrosis

BACKGROUND

Lately a potential detrimental effect of air pollution to idiopathic pulmonary fibrosis emerged. We aimed to assess the effects of short-term air pollution exposure to the clinical course of IPF.

RESEARCH DESIGN AND METHODS

IPF patients were followed intensively for four nonconsecutive study periods between 13 July 2020 and 5 September 2021. Short-term exposure to O3, NO2 and PM10 concentrations was estimated using spatio-temporal land use regression models. Associations among symptoms, lung function, oxygen saturation, and short-term personal air pollutant exposure were assessed through multiple mixed effects logistic regression models.

RESULTS

Data for up to 24 IPF patients (mean age: 72.2 ± 7.6 years) were analyzed. We detected positive significant associations between cough and a 10 μg/m3 increase in same day mean level of NO2 (OR = 1.59, 95%CI: 1.00-2.53), PM10 (OR = 2.42, 95%CI: 1.54-3.79), and O3 (OR = 1.63, 95%CI: 1.14-2.32). A 10 μg/m3 increase in same day mean level of NO2 was also associated with the risk of appearance of wheezing (OR = 3.01, 95%CI: 1.00-9.04), while exposure to O3 was associated with common cold (OR = 6.30, 95%CI: 3.59-11.07). No significant associations were detected between short-term exposure to air pollutants and forced vital capacity or saturation of oxygen.

CONCLUSIONS

Short-term exposure to increased concentrations of air pollutants is an independent risk factor for IPF symptoms' aggravation.

Clinical Utility of Bronchoalveolar Lavage Neutrophilia and Biomarkers for Evaluating Severity of Chronic Fibrosing Interstitial Lung Diseases

Introduction It is hypothesized that bronchoalveolar lavage (BAL) neutrophilia, Krebs von den Lungen-6 (KL-6), and C-reactive protein (CRP) predict the severity of chronic fibrosing interstitial lung diseases (CF-ILDs). Methods This cross-sectional study enrolled 30 CF-ILD patients. Using Pearson's correlation analysis, BAL neutrophils, KL-6, and CRP were correlated with forced vital capacity (FVC), diffusing lung capacity for carbon monoxide (DLCO), six-minute walk distance (6MWD), partial pressure of oxygen (PaO2), computed tomography fibrosis score (CTFS), and pulmonary artery systolic pressure (PASP). Using the receiver operator characteristic (ROC) curve, BAL KL-6 and CRP were evaluated against FVC% and DLCO% in isolation and combination with BAL neutrophilia for predicting the severity of CF-ILDs. Results BAL neutrophilia significantly correlated only with FVC% (r = -0.38, P = 0.04) and DLCO% (r = -0.43, P = 0.03). BAL KL-6 showed a good correlation with FVC% (r = -0.44, P < 0.05) and DLCO% (r = -0.50, P = 0.02), while BAL CRP poorly correlated with all parameters (r = 0.0-0.2). Subset analysis of BAL CRP in patients with CTFS ≤ 15 showed a better association with FVC% (r = -0.28, P = 0.05) and DLCO% (r = -0.36, P = 0.04). BAL KL-6 cut-off ≥ 72.32 U/ml and BAL CRP ≥ 14.55 mg/L predicted severe disease with area under the curve (AUC) values of 0.77 and 0.71, respectively. The combination of BAL neutrophilia, KL-6, and CRP predicted severity with an AUC value of 0.89. Conclusion The combination of BAL neutrophilia, KL-6, and CRP facilitates the severity stratification of CF-ILDs complementing existing severity parameters.

Plasma Wnt7b protein in rheumatoid arthritis: Detection of interstitial lung disease

OBJECTIVE

To determine the plasma level of Wingless-related integration site 7b (Wnt7b) protein in rheumatoid arthritis (RA) patients (with and without interstitial lung disease (ILD)) and in idiopathic pulmonary fibrosis (IPF) patients and its relationship with RA disease activity and/or severity of pulmonary fibrosis. To assess the validity of plasma Wnt7b for the detection of ILD among RA patients.

METHOD

This case-control study included 128 subjects (32 RA-ILD, 32 RA, 32 IPF, and 32 healthy controls). RA and RA-ILD Patients were evaluated for disease activity by DAS28 and disease activity grades were recorded according to DAS28 grades. Laboratory parameters as Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Rheumatoid Factor (RF), Anti-citrullinated peptide (Anti-CCP) were recorded. Plasma Wnt7b levels were measured by ELISA. Diagnosis of pulmonary fibrosis (for RA-ILD and IPF patients) was done by high resolution computed tomography (HRCT) and its severity was assessed mainly by pulmonary function test using forced vital capacity (FVC) grading.

RESULTS

Comparison of Wnt7b plasma levels showed a significant difference between the studied groups with the P-value < 0.018 (RA-ILD had the highest levels). Post hoc analysis revealed a significant difference in Wnt7b plasma levels between RA-ILD and IPF groups (P = 0.008). Also, RA-ILD and control groups had a significant difference (P = 0.039). However, there was a non-significant relationship between Wnt7b plasma levels and RA disease activity as well as the severity of pulmonary fibrosis. ROC curve analysis for the plasma Wnt7b levels revealed that a level  ≥285.1 pg/ml had a sensitivity of 87.5% and a specificity of 43.8% for the detection of ILD in RA patients with positive likelihood ratio of 1.56 and negative likelihood ratio of 0.29.

CONCLUSION

RA-ILD patients had significantly higher plasma Wnt7b levels than the controls and IPF patients. These data suggest that the Wnt7b secretion is augmented by the concomitant presence of RA with pulmonary fibrosis. In addition, plasma Wnt7b may be used as a highly sensitive test for the detection of immunologically induced fibrotic changes in lung tissue among RA patients.

External validation and longitudinal application of the DO-GAP index to individualise survival prediction in idiopathic pulmonary fibrosis

Background

The Distance-Oxygen-Gender-Age-Physiology (DO-GAP) index has been shown to improve prognostication in idiopathic pulmonary fibrosis (IPF) compared to the Gender-Age-Physiology (GAP) score. We sought to externally validate the DO-GAP index compared to the GAP index for baseline risk assessment in patients with IPF. Additionally, we evaluated the utility of serial change in the DO-GAP index in predicting survival.

Methods

We performed an analysis of patients with IPF from the Pulmonary Fibrosis Foundation-Patient Registry (PFF-PR). Discrimination and calibration of the two models were assessed to predict transplant-free survival and IPF-related mortality. Joint longitudinal time-to-event modelling was utilised to individualise survival prediction based on DO-GAP index trajectory.

Results

There were 516 patients with IPF from the PFF-PR with available demographics, pulmonary function tests, 6-min walk test data and outcomes included in this analysis. The DO-GAP index (C-statistic: 0.73) demonstrated improved discrimination in discerning transplant-free survival compared to the GAP index (C-statistic: 0.67). DO-GAP index calibration was adequate, and the model retained predictive accuracy to identify IPF-related mortality (C-statistic: 0.74). The DO-GAP index was similarly accurate in the subset of patients taking antifibrotic medications. Serial change in the DO-GAP index improved model discrimination (cross-validated area under the curve: 0.83) enabling the personalised prediction of disease trajectory in individual patients.

Conclusion

The DO-GAP index is a simple, validated, multidimensional score that accurately predicts transplant-free survival in patients with IPF and can be adapted longitudinally in individual patients. The DO-GAP may also find use in studies of IPF to risk stratify patients and possibly as a clinical trial end-point.

Derivation and validation of a simple multidimensional index incorporating exercise capacity parameters for survival prediction in idiopathic pulmonary fibrosis

INTRODUCTION

The gender-age-physiology (GAP) index is an easy-to-use baseline mortality prediction model in idiopathic pulmonary fibrosis (IPF). The GAP index does not incorporate exercise capacity parameters such as 6 min walk distance (6MWD) or exertional hypoxia. We evaluated if the addition of 6MWD and exertional hypoxia to the GAP index improves survival prediction in IPF.

METHODS

Patients with IPF were identified at a tertiary care referral centre. Discrimination and calibration of the original GAP index were assessed. The cohort was then randomly divided into a derivation and validation set and performance of the GAP index with the addition of 6MWD and exertional hypoxia was evaluated. A final model was selected based on improvement in discrimination. Application of this model was then evaluated in a geographically distinct external cohort.

RESULTS

There were 562 patients with IPF identified in the internal cohort. Discrimination of the original GAP index was measured by a C-statistic of 0.676 (95% CI 0.635 to 0.717) and overestimated observed risk. 6MWD and exertional hypoxia were strongly predictive of mortality. The addition of these variables to the GAP index significantly improved model discrimination. A revised index incorporating exercise capacity parameters was constructed and performed well in the internal validation set (C-statistic: 0.752; 95% CI 0.701 to 0.802, difference in C-statistic compared with the refit GAP index: 0.050; 95% CI 0.004 to 0.097) and external validation set (N=108 (C-statistic: 0.780; 95% CI 0.682 to 0.877)).

CONCLUSION

A simple point-based baseline-risk prediction model incorporating exercise capacity predictors into the original GAP index may improve prognostication in patients with IPF.

A Systematic Review of the Prognostic Significance of the Body Mass Index in Idiopathic Pulmonary Fibrosis

The identification of novel prognostic biomarkers might enhance individualized management strategies in patients with idiopathic pulmonary fibrosis (IPF). Although several patient characteristics are currently used to predict outcomes, the prognostic significance of the body mass index (BMI), a surrogate measure of excess fat mass, has not been specifically investigated until recently. We systematically searched PubMed, Web of Science, and Scopus, from inception to July 2022, for studies investigating associations between the BMI and clinical endpoints in IPF. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias. The PRISMA 2020 statement on the reporting of systematic reviews was followed. Thirty-six studies were identified (9958 IPF patients, low risk of bias in 20), of which 26 were published over the last five years. Significant associations between lower BMI values and adverse outcomes were reported in 10 out of 21 studies on mortality, four out of six studies on disease progression or hospitalization, and two out of three studies on nintedanib tolerability. In contrast, 10 out of 11 studies did not report any significant association between the BMI and disease exacerbation. Our systematic review suggests that the BMI might be useful to predict mortality, disease progression, hospitalization, and treatment-related toxicity in IPF (PROSPERO registration number: CRD42022353363).

Hyperpolarized 129Xe MR Spectroscopy in the Lung Shows 1-year Reduced Function in Idiopathic Pulmonary Fibrosis

Background Idiopathic pulmonary fibrosis (IPF) is a temporally and spatially heterogeneous lung disease. Identifying whether IPF in a patient is progressive or stable is crucial for treatment regimens. Purpose To assess the role of hyperpolarized (HP) xenon 129 (129Xe) MRI measures of ventilation and gas transfer in IPF generally and as an early signature of future IPF progression. Materials and Methods In a prospective study, healthy volunteers and participants with IPF were consecutively recruited between December 2015 and August 2019 and underwent baseline HP 129Xe MRI and chest CT. Participants with IPF were followed up with forced vital capacity percent predicted (FVC%p), diffusing capacity of the lungs for carbon monoxide percent predicted (DLco%p), and clinical outcome at 1 year. IPF progression was defined as reduction in FVC%p by at least 10%, reduction in DLco%p by at least 15%, or admission to hospice care. CT and MRI were spatially coregistered and a measure of pulmonary gas transfer (red blood cell [RBC]-to-barrier ratio) and high-ventilation percentage of lung volume were compared across groups and across fibrotic versus normal-appearing regions at CT by using Wilcoxon signed rank tests. Results Sixteen healthy volunteers (mean age, 57 years ± 14 [SD]; 10 women) and 22 participants with IPF (mean age, 71 years ± 9; 15 men) were evaluated, as follows: nine IPF progressors (mean age, 72 years ± 7; five women) and 13 nonprogressors (mean age, 70 years ± 10; 11 men). Reduction of high-ventilation percent (13% ± 6.1 vs 8.2% ± 5.9; P = .03) and RBC-to-barrier ratio (0.26 ± 0.06 vs 0.20 ± 0.06; P = .03) at baseline were associated with progression of IPF. Participants with progressive disease had reduced RBC-to-barrier ratio in structurally normal-appearing lung at CT (0.21 ± 0.07 vs 0.28 ± 0.05; P = .01) but not in fibrotic regions of the lung (0.15 ± 0.09 vs 0.14 ± 0.04; P = .62) relative to the nonprogressive group. Conclusion In this preliminary study, functional measures of gas transfer and ventilation measured with xenon 129 MRI and the extent of fibrotic structure at CT were associated with idiopathic pulmonary fibrosis disease progression. Differences in gas transfer were found in regions of nonfibrotic lung. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gleeson and Fraser in this issue.

Changes in serum metabolomics in idiopathic pulmonary fibrosis and effect of approved antifibrotic medication

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with significant mortality and morbidity. Approval of antifibrotic therapy has ameliorated disease progression, but therapy response is heterogeneous and to date, adequate biomarkers predicting therapy response are lacking. In recent years metabolomic technology has improved and is broadly applied in cancer research thus enabling its use in other fields. Recently both aberrant metabolic and lipidomic pathways have been described to influence profibrotic responses. We thus aimed to characterize the metabolomic and lipidomic changes between IPF and healthy volunteers (HV) and analyze metabolomic changes following treatment with nintedanib and pirfenidone. We collected serial serum samples from two IPF cohorts from Germany (n = 122) and Spain (n = 21) and additionally age-matched healthy volunteers (n = 16). Metabolomic analysis of 630 metabolites covering 14 small molecule and 12 different lipid classes was carried out using flow injection analysis tandem mass spectrometry for lipids and liquid chromatography tandem mass spectrometry for small molecules. Levels were correlated with survival and disease severity. We identified 109 deregulated analytes in IPF compared to HV in cohort 1 and 112 deregulated analytes in cohort 2. Metabolites which were up-regulated in both cohorts were mainly triglycerides while the main class of down-regulated metabolites were phosphatidylcholines. Only a minority of de-regulated analytes were small molecules. Triglyceride subclasses were inversely correlated with baseline disease severity (GAP-score) and a clinical compound endpoint of lung function decline or death. No changes in the metabolic profiles were observed following treatment with pirfenidone. Nintedanib treatment induced up-regulation of triglycerides and phosphatidylcholines. Patients in whom an increase in these metabolites was observed showed a trend towards better survival using the 2-years composite endpoint (HR 2.46, p = 0.06). In conclusion, we report major changes in metabolites in two independent cohorts testing a large number of patients. Specific lipidic metabolite signatures may serve as biomarkers for disease progression or favorable treatment response to nintedanib.

Filtration-histogram based texture analysis and CALIPER based pattern analysis as quantitative CT techniques in idiopathic pulmonary fibrosis: head-to-head comparison

OBJECTIVE

To assess the prognostic performance of two quantitative CT (qCT) techniques in idiopathic pulmonary fibrosis (IPF) compared to established clinical measures of disease severity (GAP index).

METHODS

Retrospective analysis of high-resolution CT scans for 59 patients (age 70.5 ± 8.8 years) with two qCT methods. Computer-aided lung informatics for pathology evaluation and ratings based analysis classified the lung parenchyma into six different patterns: normal, ground glass, reticulation, hyperlucent, honeycombing and pulmonary vessels. Filtration histogram-based texture analysis extracted texture features: mean intensity, standard deviation (SD), entropy, mean of positive pixels (MPPs), skewness and kurtosis at different spatial scale filters. Univariate Kaplan-Meier survival analysis assessed the different qCT parameters' performance to predict patient outcome and refine the standard GAP staging system. Multivariate cox regression analysis assessed the independence of the significant univariate predictors of patient outcome.

RESULTS

The predominant parenchymal lung pattern was reticulation (16.6% ± 13.9), with pulmonary vessel percentage being the most predictive of worse patient outcome (p = 0.009). Higher SD, entropy and MPP, in addition to lower skewness and kurtosis at fine texture scale (SSF2), were the most significant predictors of worse outcome (p < 0.001). Multivariate cox regression analysis demonstrated that SD (SSF2) was the only independent predictor of survival (p < 0.001). Better patient outcome prediction was achieved after adding total vessel percentage and SD (SSF2) to the GAP staging system (p = 0.006).

CONCLUSION

Filtration-histogram texture analysis can be an independent predictor of patient mortality in IPF patients.

ADVANCES IN KNOWLEDGE

qCT analysis can help in risk stratifying IPF patients in addition to clinical markers.

Pulmonary vascular volume is associated with DLCO and fibrotic score in idiopathic pulmonary fibrosis: an observational study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a disease that primarily occurs in elderly individuals. However, it is difficult to diagnose and has a complex disease course. High-resolution computed tomography (HRCT) and lung function testing are crucial for its diagnosis and follow-up. However, the correlation of HRCT findings with lung function test results has not been extensively investigated.

METHODS

This study retrospectively analysed the medical records and images of patients with IPF. Patients with evident emphysema and lung cancer were excluded. The diagnosis of all the included cases was confirmed following a discussion among specialists from multiple disciplines. The correlation of HRCT findings, including fibrotic score, HRCT lung volume, pulmonary artery trunk (PA) diameter and pulmonary vascular volume (PVV), with lung function test parameters, such as forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO), was analysed.

RESULTS

A total of 32 patients were included. Higher fibrotic and PVV scores were significantly correlated with lower DLCO (r =  - 0.59, p = 0.01; r =  - 0.43, p = 0.03, respectively) but not with FVC. Higher PVV score significantly correlated with higher fibrotic score (r = 0.59, p < 0.01) and PA diameter (r = 0.47, p = 0.006).

CONCLUSION

Our study demonstrated the structural and functional correlation of IPF. The extent of lung fibrosis (fibrotic score) and PVV score were associated with DLCO but not with FVC. The PA diameter, which reflects the pulmonary artery pressure, was found to be associated with the PVV score.

Real-life prevalence of progressive fibrosing interstitial lung diseases

The concept of progressive fibrosing interstitial lung disease (PF-ILD) has recently emerged. However, real-life proportion of PF-ILDs outside IPF is still hard to evaluate. Therefore, we sought to estimate the proportion of PF-ILD in our ILD cohort. We also determined the proportion of ILD subtypes within PF-ILD and investigated factors associated with PF-ILDs. Finally, we quantified interobserver agreement between radiologists for the assessment of fibrosis. We reviewed the files of ILD patients discussed in multidisciplinary discussion between January 1st 2017 and December 31st 2019. Clinical data, pulmonary function tests (PFTs) and high-resolution computed tomography (HRCTs) were centrally reviewed. Fibrosis was defined as the presence of traction bronchiectasis, reticulations with/out honeycombing. Progression was defined as a relative forced vital capacity (FVC) decline of ≥ 10% in ≤ 24 months or 5% < FVC decline < 10% and progression of fibrosis on HRCT in ≤ 24 months. 464 consecutive ILD patients were included. 105 had a diagnosis of IPF (23%). Most frequent non-IPF ILD were connective tissue disease (CTD)-associated ILD (22%), hypersensitivity pneumonitis (13%), unclassifiable ILD (10%) and sarcoidosis (8%). Features of fibrosis were common (82% of CTD-ILD, 81% of HP, 95% of uILD). After review of HRCTs and PFTs, 68 patients (19% of non-IPF ILD) had a PF-ILD according to our criteria. Interobserver agreement for fibrosis between radiologists was excellent (Cohen’s kappa 0.86). The main diagnosis among PF-ILD were CTD-ILD (36%), HP (22%) and uILD (20%). PF-ILD patients were significantly older than non-F-ILD (P = 0.0005). PF-ILDs represent about 20% of ILDs outside IPF. This provides an estimation of the proportion of patients who might benefit from antifibrotics. Interobserver agreement between radiologists for the diagnosis of fibrotic ILD is excellent.

Icariin attenuates bleomycin-induced pulmonary fibrosis by targeting Hippo/YAP pathway

Pulmonary fibrosis is a manifestation of the progression of interstitial pulmonary disease. Icariin (ICA) has been found to exhibit protective effects on multiple chronic diseases like diabetes, liver, heart, and renal fibrosis. Here, a systemic pharmacological study was designed to investigate whether ICA treatment alleviates bleomycin (BLM)-induced pulmonary fibrosis. The rat pulmonary fibrosis model was constructed by non-invasive endotracheal intubation instillation of BLM to observe the intervention effects of ICA on pulmonary fibrosis in the whole process of inflammation and fibrosis. ICA reduced the collagen deposition and inflammation induced by BLM in rat. The comparative RNA-sequencing was conducted to analyze the lung gene expression profiles in rat. KEGG analysis indicated that most of the genes were enriched in Hippo pathway, NF-κB pathway, and B-cell receptor signaling pathway, etc. Immunohistochemistry staining showed that the expression of YAP was significantly elevated in the model group and decreased in the ICA treatment group. Taken together, the anti-fibrotic effect of ICA appears to be mediated by its inhibitory of YAP, which is the core transcriptional regulator of Hippo pathway.

ACR Appropriateness Criteria® Diffuse Lung Disease

Diffuse lung disease, frequently referred to as interstitial lung disease, encompasses numerous disorders affecting the lung parenchyma. The potential etiologies of diffuse lung disease are broad with several hundred established clinical syndromes and pathologies currently identified. Imaging plays a critical role in diagnosis and follow-up of many of these diseases, although multidisciplinary discussion is the current standard for diagnosis of several DLDs. This document aims to establish guidelines for evaluation of diffuse lung diseases for 1) initial imaging of suspected diffuse lung disease, 2) initial imaging of suspected acute exacerbation or acute deterioration in cases of confirmed diffuse lung disease, and 3) clinically indicated routine follow-up of confirmed diffuse lung disease without acute deterioration. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Surgical Lung Biopsy for Interstitial Lung Disease. Safety and Feasibility at a Tertiary Referral Center

Rationale: Video-assisted thoracoscopic surgery (VATS) remains the gold standard for interstitial lung disease (ILD) characterization when histology is deemed necessary. There is diminishing use of VATS owing to increased reliance on high-resolution computed tomographic patterns, as well as concerns regarding the potential morbidity and mortality of the procedure.Objectives: The goal of this study was to evaluate the safety and tolerability of VATS among a broad group of patients with ILD referred to a tertiary care center.Methods: Data for all patients with ILD who underwent VATS lung biopsies at Inova Fairfax hospital for the period from December 2012 to September 2019 were collected. Clinical, physiologic, and functional parameters as well as postoperative outcomes including any complications, hospital length of stay, and mortality were collated.Results: There were 268 diagnostic VATS biopsies performed during the period. The mean age of the cohort was 63 ± 13 years, 54% were male, and 25% were ultimately diagnosed with idiopathic pulmonary fibrosis. Two hundred twenty-nine patients were scheduled (85%, Elective VATS group) whereas 39 were inpatients (15%). In the elective group, the 1-month complication rate was 8%, whereas 4% had a severe complication, and there were no deaths. The only mortalities were in the group who were hospitalized before the VATS (4/39 = 10%). Complications were less frequent when VATS was requested by the tertiary referral ILD team. Of the elective group, 87% patients were discharged the same day.Conclusions: This report demonstrates the safety, tolerability, and feasibility of VATS lung biopsy as a same-day procedure in the modern era, especially if patients are first vetted by a team with expertise in the field of ILD. These results support a lower threshold to pursue a VATS biopsy when histology is required for an ILD diagnosis.

Diagnostic Classification of Interstitial Lung Disease in Clinical Practice

Interstitial lung diseases (ILDs) are challenging to diagnose, requiring integration of multiple complex features that are often difficult to interpret. This article reviews a pragmatic approach to ILD diagnosis and classification, focusing on diagnostic tools and strategies that are used to separate different subtypes and identify the most appropriate management. We discuss the evolution of ILD classification and the contemporary approach that integrates routinely used diagnostic tools in a multidisciplinary discussion. We highlight the increasing importance of taking a multipronged approach to ILD classification that reflects the recent emphasis on disease behavior while also considering etiopathogenesis and morphologic features.

Identification and Validation of Potential Biomarkers and Pathways for Idiopathic Pulmonary Fibrosis by Comprehensive Bioinformatics Analysis

Objective

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, irreversible, high-mortality lung disease, but its pathogenesis is still unclear. Our purpose was to explore potential genes and molecular mechanisms underlying IPF.

Methods

IPF-related data were obtained from the GSE99621 dataset. Differentially expressed genes (DEGs) were identified between IPF and controls. Their biological functions were analyzed. The relationships between DEGs and microRNAs (miRNAs) were predicted. DEGs and pathways were validated in a microarray dataset. A protein-protein interaction (PPI) network was constructed based on these common DEGs. Western blot was used to validate hub genes in IPF cell models by western blot.

Results

DEGs were identified for IPF than controls in the RNA-seq dataset. Functional enrichment analysis showed that these DEGs were mainly enriched in immune and inflammatory response, chemokine-mediated signaling pathway, cell adhesion, and other biological processes. In the miRNA-target network based on RNA-seq dataset, we found several miRNA targets among all DEGs, like RAB11FIP1, TGFBR3, and SPP1. We identified 304 upregulated genes and 282 downregulated genes in IPF compared to controls both in the microarray and RNA-seq datasets. These common DEGs were mainly involved in cell adhesion, extracellular matrix organization, oxidation-reduction process, and lung vasculature development. In the PPI network, 3 upregulated and 4 downregulated genes could be considered hub genes, which were confirmed in the IPF cell models.

Conclusion

Our study identified several IPF-related DEGs that could become potential biomarkers for IPF. Large-scale multicentric studies are eagerly needed to confirm the utility of these biomarkers.

The role of osteoprotegerin (OPG) in fibrosis: its potential as a biomarker and/or biological target for the treatment of fibrotic diseases

Fibrosis is defined by excessive formation and accumulation of extracellular matrix proteins, produced by myofibroblasts, that supersedes normal wound healing responses to injury and results in progressive architectural remodelling. Fibrosis is often detected in advanced disease stages when an organ is already severely damaged and can no longer function properly. Therefore, there is an urgent need for reliable and easily detectable markers to identify and monitor fibrosis onset and progression as early as possible; this will greatly facilitate the development of novel therapeutic strategies. Osteoprotegerin (OPG), a well-known regulator of bone extracellular matrix and most studied for its role in regulating bone mass, is expressed in various organs and functions as a decoy for receptor activator of nuclear factor kappa-B ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Recently, OPG has been linked to fibrosis and fibrogenesis, and has been included in a panel of markers to diagnose liver fibrosis. Multiple studies now suggest that OPG may be a general biomarker suitable for detection of fibrosis and/or monitoring the impact of fibrosis treatment. This review summarizes our current understanding of the role of OPG in fibrosis and will discuss its potential as a biomarker and/or novel therapeutic target for fibrosis.

Longitudinal Changes in Clinical Features, Management, and Outcomes of Idiopathic Pulmonary Fibrosis. A Nationwide Cohort Study

Rationale: In recent decades, diagnosis and treatment recommendations for idiopathic pulmonary fibrosis (IPF) have changed. In Korea, the average life expectancy has increased, unmet healthcare needs have been reduced, and the number of computed tomographic examinations performed has nearly doubled. The Korean Interstitial Lung Disease Study Group conducted a nationwide cohort study for idiopathic interstitial pneumonia, including IPF, and established a registry for IPF.Objectives: Using study data collected by the study group, this study aimed to evaluate longitudinal changes in clinical features, diagnosis, treatment, and mortality and analyze the extent to which changes in medication usage affected IPF-associated mortality.Methods: The study population included newly diagnosed patients with IPF from a cohort study (January 2002 to September 2008, n = 1,839, 2008 group) and prospective registry (January 2012 to August 2018, n = 1,345, 2018 group). Survival curves were estimated using the Kaplan-Meier method, and Cox regression models were used to identify mortality-associated risk factors in each group.Results: The 2018 group was younger, had fewer symptoms, had less honeycombing, underwent more serologic autoimmune marker and pulmonary function tests, had higher oxygen partial pressure and lower carbon dioxide partial pressure values, was less frequently diagnosed by surgical biopsy, and had better survival than the 2008 group. Steroid use and conservative care declined, whereas N-acetylcysteine use increased in this group. Antifibrotic agents were used in only the 2018 group. In the 2008 group, N-acetylcysteine was associated with lower mortality, whereas conservative care was associated with higher mortality. In the 2018 group, the use of antifibrotic agents was associated with lower mortality, and steroid use was associated with higher mortality. The survival rates in the 2008 and 2018 non-antifibrotic agent subgroups were similar.Conclusions: This study analyzed national IPF cohort data spanning 17 years. In clinical practice, the IPF diagnosis was made earlier, steroid and immunosuppressive agent use was reduced, and antifibrotic agents were administered. The survival of patients with IPF has improved over the decades, and antifibrotic use was consistently associated with improved survival.Clinical trial registered with clinicaltrials.gov (NCT04160715).

Radiomics-based assessment of idiopathic pulmonary fibrosis is associated with genetic mutations and patient survival

Purpose: The purpose of our study was to combine differences in radiomic features extracted from lung regions in the computed tomography (CT) scans of patients diagnosed with idiopathic pulmonary fibrosis (IPF) to identify associations with genetic variations and patient survival. Approach: A database of CT scans and genomic data from 169 patients diagnosed with IPF was collected retrospectively. Six region-of-interest pairs (three per lung, positioned posteriorly, anteriorly, and laterally) were placed in each of three axial CT sections for each patient. Thirty-one features were used in logistic regression to classify patients' genetic mutation status; classification performance was evaluated through the area under the receiver operating characteristic (ROC) curve [average area under the ROC curve (AUC)]. Kaplan-Meier (KM) survival curve models quantified the ability of each feature to differentiate between survival curves based on feature-specific thresholds. Results: Nine first-order texture features and one fractal feature were correlated with TOLLIP-1 (rs4963062) mutations (AUC: 0.54 to 0.74), and five Laws' filter features were correlated with TOLLIP-2 (rs5743905) mutations (AUC: 0.53 to 0.70). None of the features analyzed were found to be correlated with MUC5B mutations. First-order and fractal features demonstrated the greatest discrimination between KM curves. Conclusions: A radiomics approach for the correlation of patient genetic mutations with image texture features has potential as a biomarker. These features also may serve as prognostic indicators using a survival curve modeling approach in which the combination of radiomic features and genetic mutations provides an enhanced understanding of the interaction between imaging phenotype and patient genotype on the progression and treatment of IPF.

Fully Automated Segmentation of Pulmonary Fibrosis Using Different Software Tools

OBJECTIVE

Evaluation of software tools for segmentation, quantification, and characterization of fibrotic pulmonary parenchyma changes will strengthen the role of CT as biomarkers of disease extent, evolution, and response to therapy in idiopathic pulmonary fibrosis (IPF) patients.

METHODS

418 nonenhanced thin-section MDCTs of 127 IPF patients and 78 MDCTs of 78 healthy individuals were analyzed through 3 fully automated, completely different software tools: YACTA, LUFIT, and IMBIO. The agreement between YACTA and LUFIT on segmented lung volume and 80th (reflecting fibrosis) and 40th (reflecting ground-glass opacity) percentile of the lung density histogram was analyzed using Bland-Altman plots. The fibrosis and ground-glass opacity segmented by IMBIO (lung texture analysis software tool) were included in specific regression analyses.

RESULTS

In the IPF-group, LUFIT outperformed YACTA by segmenting more lung volume (mean difference 242 mL, 95% limits of agreement -54 to 539 mL), as well as quantifying higher 80th (76 HU, -6 to 158 HU) and 40th percentiles (9 HU, -73 to 90 HU). No relevant differences were revealed in the control group. The 80th/40th percentile as quantified by LUFIT correlated positively with the percentage of fibrosis/ground-glass opacity calculated by IMBIO (r = 0.78/r = 0.92).

CONCLUSIONS

In terms of segmentation of pulmonary fibrosis, LUFIT as a shape model-based segmentation software tool is superior to the threshold-based YACTA, tool, since the density of (severe) fibrosis is similar to that of the surrounding soft tissues. Therefore, shape modeling as used in LUFIT may serve as a valid tool in the quantification of IPF, since this mainly affects the subpleural space.

A Physician's Guide for Workers' Return to Work During COVID-19 Pandemic

OBJECTIVE

Higher probability of developing severe COVID-19 has been associated with health risk factors and medical conditions which are common among workers globally. For at risk workers, return to work may require additional protective policies and procedures.

METHODS

A review of the medical literature was conducted on health risk factors and medical conditions associated with increased COVID-19 morbidity and mortality, standardized measures for community COVID transmission, and occupation-specific risk.

RESULTS

The relative risk of acquiring and the severity of COVID-19 for workers is associated with three pillars: individual risk, workplace risk, and community risk. Matrices were developed to determine a worker's individual risk based on these three pillars.

CONCLUSIONS

A practical decision tool is proposed for physicians evaluating and managing individual worker COVID-19 risk in the context of returning to work.

Performance of semi-quantitative lung ultrasound in the assessment of disease severity in interstitial lung disease

BACKGROUND:

Accurate staging of disease severity and its serial monitoring thus is central to the effective management protocols of interstitial lung disease (ILD).

PURPOSE:

The aim is to evaluate the effectiveness of semi-quantitative parameters of lung ultrasound (LUS) in patients of ILD as a means of staging disease severity.

MATERIALS AND METHODS:

LUS of 47 patients of ILD and 20 age-matched controls was performed, and findings such as B-line distance, pleural thickening, subpleural changes, decreased lung sliding, and fragmented pleural lining were charted, and an LUS score was done using these parameters. Findings were compared with the Modified Medical Research Council (MMRC) dyspnea grade and spirometry parameters.

RESULTS:

The presence of B-lines and fragmented pleural lining were the most common findings observed in patients of ILD. Predicted forced vital capacity (FVC) and predicted forced expiratory volume in 1 s (FEV1) showed a good correlation with all the LUS parameters. B-line distance was the most significant LUS parameter to predict the variability in predicted FEVI, FVC, and MMRC dyspnea score. LUS severity score also showed good negative correlation with predicted FEV1 (r = −0.674, P < 0.001) and predicted FVC (r = −0.65, P < 0.001). LUS severity score of 4 or more predicted MMRC dyspnea score of > 3 with 82% sensitivity and 70% specificity.

CONCLUSION:

Semi-quantitative LUS score and B-line distance can provide a simple but effective estimate of disease severity in ILD.

Quantitative Evaluation of Fibrosis in IPF Patients: Meaning of Diffuse Pulmonary Ossification

To investigate the role of diffuse pulmonary ossification (DPO) in disease severity in a population of Idiopathic Pulmonary Fibrosis (IPF) patients. This retrospective study was carried out on 95 IPF patients-44 with DPO on high resolution computed tomography (HRCT) and 51 with no calcifications detected on HRCT. Pulmonary Function Tests (PFTs) acquired nearest to the HRCT were collected. Images were analyzed by two radiologists using a qualitative method, based on HRCT fibrosis visual score, and using a quantitative method, based on histogram-based analysis. The Spearman's rank correlation coefficient was used to measure the strength and direction of the linear relationship between HRCT fibrosis score and PFTs; in addition, Spearman's rank correlation coefficient was used to explore the relationships between HRCT fibrosis score and quantitative index and between quantitative indexes and PFTs. A weak correlation between HRCT fibrosis score and PFTs was proven (r =-0.014 and p = 0.9347 for FVC (Forced Vital Capacity), r = -0.379 and p = 0.0174 for DLCO (Carbon monoxide diffusing capacity)). We found a moderate negative correlation between HRCT fibrosis score and kurtosis (r = -0.448, p = 0.004272) and skewness (r = -0.463, p = 0.003019) and a weak positive correlation with High Attenuation Area (HAA)% (r = 0.362, p = 0.0235). Moreover, a moderate linear correlation between Quantitative Indexes and FVC (r = 0.577, p = 0.000051 for kurtosis and FVC, r = 0.598, p = 0.000023 for skewness and FVC, r = -0.519, p = 0.0000364 for HAA% and FVC) and between quantitative indexes and DLCO (r = 0.469, p = 0.001508 for kurtosis, and DLCO, r = 0.474, p = 0.001309 for skewness and DLCO, r = -0.412, p = 0.005996 for HAA% and DLCO) was revealed. To better investigate the influence of DPO in disease progression, a longitudinal evaluation should be performed.

Idiopathic pulmonary fibrosis patients with severe physiologic impairment: characteristics and outcomes

RESEARCH QUESTION

There is no widely accepted grading system for IPF disease severity, although physiologic impairment based on pulmonary function testing is frequently employed. We sought to describe clinical and functional characteristics as well as outcomes of patients with severe physiologic impairment.

PATIENTS AND METHODS

IPF patients with severe physiologic impairment defined by FVC ≤ 50% and/or DLco ≤ 30% predicted evaluated in the Inova Advanced Lung Disease Program between 2011 and 2019 were included. Demographic, physiologic, functional treatment and outcome data were collated.

RESULTS

There were 531 patients with IPF evaluated of whom 242 (46%) had severe physiologic impairment. Mean age was 72 ± 8 years; baseline FVC was 53 ± 17% and DL_CO 28 ± 9% of predicted. The mean 6 min walks test (6MWT) distance was 304 ± 121 m with 59% of the patients requiring supplemental oxygen ([Formula: see text] group). There was a poor correlation between the 6MWT distance and both FVC% and DLco%. Patients in the 6MWT_RA group had a better transplant-free survival than the [Formula: see text] group (p = 0.002). Patients managed before October 2014 and not receiving antifibrotic therapy had worse outcomes with reduced transplant-free survival compared with patients presenting after this date who did receive antifibrotic therapy (n = 113) (log rank p < 0.0001).

CONCLUSION

IPF patients often present with severe physiologic impairment which may be poorly correlated with their functional status. Assessment of IPF disease severity should not be based on physiologic impairment alone, but should also encompass functional status as well as need for supplemental oxygen. Antifibrotic therapy in patients with severe physiologic impairment is associated with improved outcomes.

What parameters can be used to identify early idiopathic pulmonary fibrosis?

Elucidating the disease process of early idiopathic pulmonary fibrosis (IPF) will help clinicians in addressing the contentious issues of when and in which patients, therapeutic intervention should be initiated. Here, we discuss several possible parameters for diagnosing early IPF and their clinical impacts. Physiologically, early IPF can be considered as IPF with normal or mild impairment in pulmonary function. Radiologically, early IPF can be considered as IPF with a small extent and/or early features of fibrosis. Symptomatically, early IPF can be considered as asymptomatic or less symptomatic IPF. IPF at Gender-Age-Physiology index stage I can be considered early IPF. Interstitial lung abnormalities are defined as parenchymal abnormalities in more than 5% of the lung in patients with no prior history of interstitial lung disease, and in some cases, this seems to be equivalent to early IPF. Previous clinical trials showed the effect of antifibrotic therapies in early IPF, but the effects of therapy are uncertain in early IPF outside of clinical trials, such as in cases of IPF with normal pulmonary function, IPF without honeycombing or traction bronchiectasis, and asymptomatic IPF. Moreover, little has been reported on disease progression in such conditions. Because the conceptual framework of early IPF may vary depending on its definition, not only is a diagnosis of early IPF important but prediction of disease progression is also crucial. Further investigations are needed to identify biomarkers that can detect patients who may experience greater degrees of disease progression and require treatment even with those forms of early IPF.

Oscillometry and computed tomography findings in patients with idiopathic pulmonary fibrosis

Although the utility of oscillometry for predicting disease severity in idiopathic pulmonary fibrosis (IPF) had been researched, little has been reported on the mechanism of why respiratory impedance reflects disease severity. In addition, traction bronchiectasis has been considered to reduce respiratory resistance and correlate negatively with airflow obstruction, but this hypothesis has not been validated. The present study aimed to investigate the correlations between oscillometric parameters and fibrosis-related lung abnormalities in IPF and to assess the utility of oscillometry as a surrogate marker for traction bronchiectasis and airflow obstruction.

Eighty Japanese patients with IPF underwent high-resolution computed tomography (HRCT), spirometry, and oscillometry and were retrospectively investigated. Fibrosis-related HRCT findings were scored regarding airspace consolidation, honeycombing, architectural distortion, traction bronchiectasis, and fibrosis. Correlations between the HRCT scores, spirometric parameters, and oscillometric parameters were analysed.

Respiratory reactance correlated positively with all fibrosis-related HRCT scores. Vital capacity and forced vital capacity (FVC) correlated negatively with oscillometric parameters and HRCT scores, reflecting the severity of restrictive ventilatory deficiency. Respiratory resistance was not related to any of the HRCT scores or forced expiratory volume in 1 s/FVC. However, forced expiratory volume in 1 s/FVC correlated positively with HRCT scores, which showed that airflow obstruction became milder as the disease progressed.

In conclusion, respiratory reactance reflects fibrosis and restrictive ventilatory deficiency in IPF. Moreover, respiratory resistance is independent of traction bronchiectasis and airflow obstruction in patients with IPF, which implies that respiratory resistance might reflect different properties of the airways.

Respiratory reactance measured by oscillometry correlates with fibrosis-related computed tomography findings in idiopathic pulmonary fibrosis (IPF). Respiratory resistance is independent of traction bronchiectasis and airflow obstruction in IPF.https://bit.ly/36zoGtf

Visual and quantitative assessment of HRCT pulmonary changes in idiopathic interstitial pneumonia with PFT correlation

Background

Our study was designed to correlate the degree of parenchymal affection in idiopathic interstitial pneumonia using visual and semi-quantitative HRCT assessment with pulmonary function test results.

The study involved 50 patients diagnosed as idiopathic interstitial pneumonia. They were referred from a chest outpatient clinic to the Radiology Department in the Faculty of Medicine, Cairo University for HRCT assessment in the period from January 2017 to March 2019. Variable lung parenchymal affection was studied using HRCT and variable post acquisition processing (multi-planar reconstruction, volumetric assessment, 3D color-coded images).

Results

Usual interstitial pneumonia was the most common type of IP, found in approximately 40 patients (80% of cases) followed by nonspecific interstitial pneumonia found in 5 patients (10% of cases) and lymphocytic interstitial pneumonia found in 3 patients (6% of cases), and desquamative interstitial pneumonia was the least common type of IP, found only in 2 patients (4% of cases).

Honeycombing was significantly correlated with FVC%, FEV1%, and FEV1/FVC% (p = 0.013, p = <0.001, p = 0.002 respectively). Also, reticular was significantly correlated with FVC% (p = 0.041).

Conclusion

Semi-quantitative image analysis, including the use of machine learning, provides a great deal of promise in the ILD field; such methods may be used together with visual analysis to obtain the most accurate diagnostic and prognostic information.

Summary/keywords

HRCT is most sensitive in the detection of ILD than chest radiography or conventional chest computed tomography (CT). Advances in HRCT scanning and interpretation have facilitated and improved accuracy for use in diagnosing idiopathic pulmonary fibrosis (IPF), eliminating the need for a surgical biopsy in many patients. Consequently, HRCT scans became sufficient to allow a confident IPF diagnosis

It is important to note that there are potential differences in interpretation of HRCT patterns between thoracic radiologists. However, these differences seem to be in general within a clinically acceptable range of observer variation and can be partially mitigated by review of difficult cases at ILD referral centers.

Semi-quantitative CT assessment is increasingly being used in ILD to identify pulmonary abnormalities and diagnose specific ILDs; recent studies showed that outcomes of computer-assisted imaging can be correlated with lung function tests and degree of dyspnea and functional disability

This study was designed to correlate the degree of parenchymal affection in IP using visual and semi-quantitative HRCT assessment with PFT results. Semi-quantitative imaging, including color-coded images (HU related), is a new and promising approach in the field of ILD diagnosis and prognosis.

Computer-aided analysis in evaluation and grading of interstitial lung diseases in correlation with CT-based visual scoring and pulmonary function tests

Background

Interstitial lung diseases (ILDs) represent a large group of more than 200 different entities. High resolution computed tomography (HRCT) is accepted as the gold standard imaging modality in the diagnosis of ILD. The visual-based scoring offers an advantage in finding a specific type of ILD. Computer-aided CT attenuation histogram is another way of characterizing and quantifying diffuse lung disease. The histogram analysis (HIST) consists of calculating skewness, kurtosis, and mean lung density to quantify lung disease and monitor progression. The aim of our study was to investigate the value of computer-aided analysis of HRCT for interstitial lung diseases in correlation with scoring and pulmonary function tests.

Results

This prospective study included 50 patients with suspected ILD. The mean age of patients was 46.7 years ± 12.5. Mean forced expiratory volume FEV1 was 63.6 ± 20.9. HRCT examination was done for all patients followed by CT-based visual scaling. Most of the studied patients (43.3%) had a CT visual semi-quantitative scoring ranged between 40 and 64. CT-based lung density histograms (LDH) were obtained for all patients using the 3D Slicer Software (Chest Imaging Platform). There was a significant difference between patient’s groups of different (mild, moderate, and severe) grades of ILD according to FEV1 regarding MLD, skewness, and kurtosis of corresponding CT-based density histograms (p values < 0.001). More significant and higher correlation was observed between computerized aided CT quantified mean lung densities (MLD) and (FEV1) (p value < 0.001 and r = − 0.570). The ROC curve analysis demonstrated good performance for CT visual scoring with PFT (AUC = 0.71); a cutoff scoring 15 or higher was associated with best sensitivity (75%) and specificity (100%). Meanwhile, ROC curve analysis for MLD and FEV1 demonstrated an excellent performance for computer-based CT quantification (AUC = 0.85) with a value of − 769 HU which increased sensitivity to 65% and specificity to 100%.

Conclusion

Visual-based scoring techniques offer an advantage in finding a specific type of ILD. Computer-based quantification system could be a means for accurately monitoring the disease progression or response to therapy.

AI-driven quantification, staging and outcome prediction of COVID-19 pneumonia

Coronavirus disease 2019 (COVID-19) emerged in 2019 and disseminated around the world rapidly. Computed tomography (CT) imaging has been proven to be an important tool for screening, disease quantification and staging. The latter is of extreme importance for organizational anticipation (availability of intensive care unit beds, patient management planning) as well as to accelerate drug development through rapid, reproducible and quantified assessment of treatment response. Even if currently there are no specific guidelines for the staging of the patients, CT together with some clinical and biological biomarkers are used. In this study, we collected a multi-center cohort and we investigated the use of medical imaging and artificial intelligence for disease quantification, staging and outcome prediction. Our approach relies on automatic deep learning-based disease quantification using an ensemble of architectures, and a data-driven consensus for the staging and outcome prediction of the patients fusing imaging biomarkers with clinical and biological attributes. Highly promising results on multiple external/independent evaluation cohorts as well as comparisons with expert human readers demonstrate the potentials of our approach.

Perioperative risk factors in patients with idiopathic pulmonary fibrosis: a historical cohort study

PURPOSE

Perioperative complications of patients with idiopathic pulmonary fibrosis (IPF) are not well described. The aim of this study was to identify risk factors associated with adverse postoperative outcomes in IPF patients.

METHODS

We performed a single-centre historical cohort study of adult patients with IPF who underwent surgery between 2008 and 2018. We analyzed the prognostic utility of select perioperative factors for postoperative acute exacerbation of IPF (AE-IPF), acute respiratory worsening (ARW), pneumonia, and 30-day and one-year mortality using univariable and multivariable regression analyses. To adjust for multiple interactions, the false discovery rate (Q value) was utilized to appropriately adjust P values and a Q value < 0.05 was considered to be significant.

RESULTS

Two hundred and eighty-two patients were identified. After excluding emergency cases and bronchoscopies performed for active pneumonia, 14.2% of the cohort developed ARW that persisted > 24 hr after surgery, 5.0% had AE-IPF, and 9.2% were diagnosed with postoperative pneumonia within 30 days of surgery. The 30-day mortality was 6.0% and the one-year mortality was 14.9%. Preoperative home oxygen use (relative risk [RR], 2.70; 95% confidence interval [CI], 1.50 to 4.86; P < 0.001) and increasing surgical time (per 60 min) (RR, 1.03; 95% CI, 1.02 to 1.05; P < 0.001) were identified as independent risk factors for postoperative ARW.

CONCLUSIONS

In IPF patients, preoperative home oxygen requirement and increasing surgical time showed a strong relationship with postoperative ARW and may be useful markers for perioperative risk stratification. Facteurs de risque périopératoires des patients atteints de fibrose pulmonaire idiopathique : une étude de cohorte historique.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Lung transplantation for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is characterized by relentlessly progressive lung function impairment that is consistently fatal in the absence of lung transplantation, as no curative pharmacological treatment exists. The pace of progression varies across patients, and acute life-threatening exacerbations occur unpredictably, causing further sharp drops in lung function. Recently introduced antifibrotic agents slow the pace of disease progression and may improve survival but fail to stop the fibrotic process. Moreover, the magnitude and kinetics of the response to these drugs cannot be predicted in the individual patient. These characteristics require that lung transplantation be considered early in the course of the disease. However, given the shortage of donor lungs, lung transplantation must be carefully targeted to those patients most likely to benefit. Current guidelines for lung transplantation listing may need reappraisal in the light of recent treatment advances. Patients with IPF often have multiple comorbidities such as coronary heart disease, frailty, and gastro-oesophageal reflux disease (GERD). Consequently, extensive screening for and effective treatment of concomitant conditions is crucial to appropriate candidate selection and outcome optimisation. A multidisciplinary approach is mandatory. Pulmonologists with expertise in IPF must work closely with lung transplant teams. Careful consideration must be given to preoperative optimisation, surgical technique, and pulmonary rehabilitation to produce the best post-transplantation outcomes.

Bacterial burden in the lower airways predicts disease progression in idiopathic pulmonary fibrosis and is independent of radiological disease extent

Increasing bacterial burden in the lower airways of patients with idiopathic pulmonary fibrosis confers an increased risk of disease progression and mortality. However, it remains unclear whether this increased bacterial burden directly influences progression of fibrosis or simply reflects the magnitude of the underlying disease extent or severity.We prospectively recruited 193 patients who underwent bronchoscopy and received a multidisciplinary diagnosis of idiopathic pulmonary fibrosis. Quantification of the total bacterial burden in bronchoalveolar lavage fluid was performed by 16S rRNA gene qPCR. Imaging was independently evaluated by two readers assigning quantitative scores for extent, severity and topography of radiographic changes and relationship of these features with bacterial burden was assessed.Increased bacterial burden significantly associated with disease progression (HR 2.1; 95% CI 1.287-3.474; p=0.0028). Multivariate stepwise regression demonstrated no relationship between bacterial burden and radiological features or extent of disease. When specifically considering patients with definite or probable usual interstitial pneumonia there was no difference in bacterial burden between these two groups. Despite a postulated association between pleuroparenchymal fibroelastosis and clinical infection, there was no relationship between either the presence or extent of pleuroparenchymal fibroelastosis and bacterial burden.We demonstrate that bacterial burden in the lower airways is not simply secondary to the extent of the underlying architectural destruction of the lung parenchyma seen in idiopathic pulmonary fibrosis. The independent nature of this association supports a relationship with the underlying pathogenic mechanisms and highlights the urgent need for functional studies.