Progressive fibrosing interstitial lung disease: prevalence and clinical outcome

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.

Progressive pulmonary fibrosis (PPF): Estimation of incidence and treatment rates in Japan using a claims database

BACKGROUND

Interstitial lung diseases (ILDs) are a heterogeneous group of disorders, a subset of which develop progressive pulmonary fibrosis (PPF). There is little information on the epidemiology and treatment of PPFs in Japan. This retrospective cohort study estimated the incidence probability of progression to PPFs in patients with fibrosing ILDs other than idiopathic pulmonary fibrosis in a real-world Japanese setting. Management procedures and treatment patterns were also quantified.

METHODS

Data were extracted from the Medical Data Vision database from 01-Jan-2012 to 28-May-2020, comprising a 6.91-year patient identification period, 1-year pre-index period, and post-index period. The primary outcome was the cumulative incidence probability of progression to PPF up to 24 months. Subgroup analyses were performed by the presence/absence of connective tissue disease-ILD and by pre-specified ILD clinical diagnosis.

RESULTS

Of the 34,960 eligible patients (mean age: 71.1 years, males: 52.5%), 14,580 (41.7%) progressed to PPF. The 24-month incidence probability of progression to PPF was 39.5%. A relatively comparable percentage of patients progressed across all ILD subtypes. Oral corticosteroids and tacrolimus were the most common therapies during the pre- and post-index periods. Treatment rates were very low in the post-index period.

CONCLUSIONS

This is the first claims database study to estimate the incidence probability of progression to PPF in Japan. Progression appeared common in patients with chronic fibrosing ILDs, with comparable percentages of patients across all subtypes developing PPF at 2 years. Future studies should assess the impact of regular monitoring and early intervention on treating fibrotic ILDs and preventing progression.

Presence of focal usual interstitial pneumonia is a key prognostic factor in progressive pulmonary fibrosis

AIMS

Progressive pulmonary fibrosis (PPF) is a newly recognised clinical phenotype of interstitial lung diseases in the 2022 interstitial pulmonary fibrosis (IPF) guidelines. This category is based entirely on clinical and radiological factors, and the background histopathology is unknown. Our objective was to investigate the histopathological characteristics of PPF and to examine the correlation between usual interstitial pneumonia (UIP) and prognosis in this new disease type. We hypothesised that the presence of UIP-like fibrosis predicts patients' survival in PPF cases.

METHODS AND RESULTS

We selected 201 cases fulfilling the clinical criteria of PPF from case archives. Cases diagnosed as IPF by a multidisciplinary team were excluded. Whole slide images were evaluated by three pathologists who were blinded to clinical and radiological data. We measured areas of UIP-like fibrosis and calculated what percentage of the total lesion area they occupied. The presence of focal UIP-like fibrosis amounting to 10% or more of the lesion area was seen in 148 (73.6%), 168 (83.6%) and 165 (82.1%) cases for each pathologist, respectively. Agreement of the recognition of UIP-like fibrosis in PPF cases was above κ = 0.6 between all pairs. Survival analysis showed that the presence of focal UIP-like fibrosis correlated with worsened survival under all parameters tested (P < 0.001).

CONCLUSIONS

The presence of UIP-like fibrosis is a core pathological feature of clinical PPF, and its presence within diseased areas is associated with poorer prognosis. This study highlights the importance of considering the presence of focal UIP-like fibrosis in the evaluation and management of PPF.

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.

A study on the prevalence and prognosis of progressive pulmonary fibrosis: A retrospective observational study

Interstitial lung disease (ILD) encompasses a heterogeneous group of more than 200 diffuse parenchymal lung diseases with various clinical courses. Disease progression is one of the most important prognostic factors, and, the definition of progressive pulmonary fibrosis (PPF) has recently been established. This study aimed to estimate the prevalence, risk factors, and prognosis of PPF among patients with non-idiopathic pulmonary fibrosis (IPF) in real-world practice. A total of 215 patients were retrospectively analyzed between January 2010 and June 2023 at the Haeundae Paik Hospital in the Republic of Korea. According to the criteria proposed in 2022 by Raghu et al, PPF defined as a condition that satisfies 2 or more of the following in the past year: worsening of respiratory symptoms, physiological evidence of disease progression, and radiological evidence of disease progression. The median age of the subjects was 67 years and 63.7% were female. A total of 40% was diagnosed with PPF and connective tissue disease-associated ILD (52.3%) was the most common type, followed by nonspecific interstitial pneumonitis (NSIP) (25.6%) and cryptogenic organizing pneumonitis (16.3%). In multivariate logistic regression for predicting PPF, both the use of steroids and immunosuppressants (OR: 2.57, 95% CI: 1.41-4.67, P = .002) and home oxygen use (OR: 25.17, 95% CI: 3.21-197.24, P = .002) were independent risk factors. During the follow-up period, the mortality rate was significantly higher in the PPF group than in the non-PPF group (24.4% vs 2.3%, P < .001). In the survival analysis using the Cox proportional hazard regression model, disease progression, older age and lower forced vital capacity (FVC) were independent risk factors for mortality. Our study demonstrated that the prevalence of PPF was 40%. Concomitant therapy of steroids with an immunosuppressants and home oxygen use are risk factors for PPF. PPF itself was significantly associated with high mortality rates. Risk factors for mortality were disease progression, older age, and lower FVC.

Molecular Hydrogen as a Promising Therapy Could Be Linked With Increased Resting Treg Cells or Decreased Fas+ T Cell Subsets in a IgG4-PF-ILD Patient: A Case Report

BACKGROUND/AIM

Progressive fibrosing interstitial lung disease (PF-ILD) refers to a group of chronic lung conditions commonly associated with immunoglobulin G4-related disorders. It is characterized by progressive scarring (fibrosis) within the pulmonary interstitium, resulting in respiratory failure and early mortality. Some patients do not respond to standard therapeutic interventions. Numerous studies have confirmed the anti-inflammatory and antioxidant properties of molecular hydrogen in various disease models.

CASE REPORT

In this report, we present a case study of an 85-year-old female diagnosed with suspected IgG4-related PF-ILD complicated by hospital-acquired pneumonia. On the fourth day of hydrogen-assisted therapy, a noticeable improvement in lung infiltrations was observed in chest X-rays as the patient gradually progressed towards weaning off mechanical ventilation. To assess treatment responses, we compared immune phenotypes before and after hydrogen treatment. A marked increase was observed in resting regulatory T cell levels after treatment, accompanied by a notable decrease in Fas+ helper T cell and cytotoxic T cell subtypes.

CONCLUSION

This case study highlights the effectiveness of hydrogen-assisted therapy in managing PF-ILD complicated by pneumonia, warranting further research in the future.

Progressive Pulmonary Fibrosis: Where Are We Now?

Interstitial lung diseases (ILDs) are a diverse collection of lung disorders sharing similar features, such as inflammation and fibrosis. The diagnosis and management of ILD require a multidisciplinary approach using clinical, radiological, and pathological evaluation. Progressive pulmonary fibrosis (PPF) is a distinct form of progressive and fibrotic disease, occurring in ILD cases other than in idiopathic pulmonary fibrosis (IPF). It is defined based on clinical symptoms, lung function, and chest imaging, regardless of the underlying condition. The progression to PPF must be monitored through a combination of pulmonary function tests (forced vital capacity [FVC] and diffusing capacity of the lung for carbon monoxide), an assessment of symptoms, and computed tomography scans, with regular follow-up. Although the precise mechanisms of PPF remain unclear, there is evidence of shared pathogenetic mechanisms with IPF, contributing to similar disease behavior and worse prognosis compared to non-PPF ILD. Pharmacological treatment of PPF includes immunomodulatory agents to reduce inflammation and the use of antifibrotics to target progressive fibrosis. Nintedanib, a known antifibrotic agent, was found to be effective in slowing IPF progression and reducing the annual rate of decline in FVC among patients with PPF compared to placebos. Nonpharmacological treatment, including pulmonary rehabilitation, supplemental oxygen therapy, and vaccination, also play important roles in the management of PPF, leading to comprehensive care for patients with ILD. Although there is currently no cure for PPF, there are treatments that can help slow the progression of the disease and improve quality of life.

Prediction of progressive fibrosing interstitial lung disease in patients with systemic sclerosis: insight from the CRDC cohort study

BACKGROUND

This study aims to establish a reliable prediction model of progressive fibrosing interstitial lung disease (PF-ILD) in patients with systemic sclerosis (SSc)-ILD, to achieve early risk stratification and to help better in preventing disease progression.

METHODS

304 SSc-ILD patients with no less than three pulmonary function tests within 6-24 months were included. We collected data at baseline and compared differences between SSc patients with and without PF-ILD. Least absolute shrinkage and selection operator regularisation regression and multivariable Cox regression were used to construct the prediction model, which were presented as nomogram and forest plot.

RESULTS

Among the 304 patients with SSc-ILD included, 92.1% were women, with a baseline average age of 46.7 years. Based on the 28 variables preselected by comparison between SSc patients without PF-ILD group (n=150) and patients with SSc PF-ILD group (n=154), a 9-variable prediction model was constructed, including age≥50 years (HR 1.8221, p=0.001), hyperlipidemia (HR 4.0516, p<0.001), smoking history (HR 3.8130, p<0.001), diffused cutaneous SSc subtype (HR 1.9753, p<0.001), arthritis (HR 2.0008, p<0.001), shortness of breath (HR 2.0487, p=0.012), decreased serum immunoglobulin A level (HR 2.3900, p=0.002), positive anti-Scl-70 antibody (HR 1.9573, p=0.016) and usage of cyclophosphamide/mycophenolate mofetil (HR 0.4267, p<0.001). The concordance index after enhanced bootstrap resampling adjustment was 0.874, while the optimism-corrected Brier Score was 0.144 in internal validation.

CONCLUSION

This study developed the first prediction model for PF-ILD in patients with SSc-ILD, and internal validation showed favourable accuracy and stability of the model.

Fibrotic Pulmonary Sarcoidosis

Fibrotic pulmonary sarcoidosis (fPS) affects about 20% of patients. fPS carries a significant morbidity and mortality. However, its prognosis is highly variable, depending mainly on fibrosis extent, functional impairment severity, and the development of pulmonary hypertension. Moreover, fPS outcomes are also influenced by several other complications, including acute exacerbations, and infections. fPS natural history is unknown, in particular regarding the risk of progressive self-sustaining fibrosis. The management of fPS is challenging, including anti-inflammatory treatment if granulomatous activity persists, rehabilitation, and in highly selected patients antifibrotic treatment and lung transplantation.

Developing the Lung Graph-Based Machine Learning Model for Identification of Fibrotic Interstitial Lung Diseases

Accurate detection of fibrotic interstitial lung disease (f-ILD) is conducive to early intervention. Our aim was to develop a lung graph-based machine learning model to identify f-ILD. A total of 417 HRCTs from 279 patients with confirmed ILD (156 f-ILD and 123 non-f-ILD) were included in this study. A lung graph-based machine learning model based on HRCT was developed for aiding clinician to diagnose f-ILD. In this approach, local radiomics features were extracted from an automatically generated geometric atlas of the lung and used to build a series of specific lung graph models. Encoding these lung graphs, a lung descriptor was gained and became as a characterization of global radiomics feature distribution to diagnose f-ILD. The Weighted Ensemble model showed the best predictive performance in cross-validation. The classification accuracy of the model was significantly higher than that of the three radiologists at both the CT sequence level and the patient level. At the patient level, the diagnostic accuracy of the model versus radiologists A, B, and C was 0.986 (95% CI 0.959 to 1.000), 0.918 (95% CI 0.849 to 0.973), 0.822 (95% CI 0.726 to 0.904), and 0.904 (95% CI 0.836 to 0.973), respectively. There was a statistically significant difference in AUC values between the model and 3 physicians (p < 0.05). The lung graph-based machine learning model could identify f-ILD, and the diagnostic performance exceeded radiologists which could aid clinicians to assess ILD objectively.

Abatacept in usual and in non-specific interstitial pneumonia associated with rheumatoid arthritis

OBJECTIVE

To compare the effectiveness of abatacept (ABA) in Rheumatoid Arthritis-associated Interstitial Lung Disease (RA-ILD) according to the radiological patterns of usual (UIP) or non-specific interstitial pneumonia (NSIP).

METHODS

From an observational longitudinal multicentre study of 263 RA-ILD patients treated with ABA, those with UIP or NSIP were selected. Lung function, chest high resolution computerised tomography (HRCT) and dyspnoea were recorded and compared in both groups from baseline to the end of follow-up (progression definitions: improvement or worsening >10% of FVC or DLCO, changes in HRCT extension and 1-point change in the mMRC scale, respectively). Differences between final and baseline visits were calculated as the average difference (95% CI) through mixed effects models regression.

RESULTS

We studied 190 patients with UIP (n=106) and NSIP (n=84). General features were similar in both groups except for older age, positive rheumatoid factor, and previous sulfasalazine therapy, which were more frequent in patients with UIP. ILD duration up to ABA initiation was relatively short: median 16 [4-50] and 11 [2-36] months (p=0.36) in UIP and NSIP, respectively. Mean baseline FVC and DLCO were 82% and 63% in UIP and 89% and 65% in NSIP, respectively. Both parameters remained stable during 24 months with ABA. HRCT lesions and dyspnoea improved/stabilized in 73.1% and 90.5% and 72.9% and 94.6% of UIP and NSIP patterns, respectively.

CONCLUSION

ABA seems equally effective in stabilizing dyspnoea, lung function and radiological impairment in both UIP and NSIP patterns of RA-ILD. Early administration of ABA may prevent RA-ILD progression, regardless of the radiological pattern.

Rationale and design of the prognostic transcriptomic signature in fibrotic hypersensitivity pneumonitis (PREDICT) study

Hypersensitivity pneumonitis is an immunologically mediated form of lung disease, resulting from inhalational exposure to a large variety of antigens. A subgroup of patients with fibrotic hypersensitivity pneumonitis (FHP) develop symptomatic, functional and radiographic disease progression. Mortality occurs primarily from respiratory failure as a result of progressive and self-sustaining lung injury that often occurs despite immunosuppression and removal of the inciting antigen. The development and validation of a prognostic transcriptomic signature for FHP (PREDICT-HP) is an observational multicentre cohort study designed to explore a transcriptomic signature from peripheral blood mononuclear cells in patients with FHP that is predictive of disease progression. This article describes the design and rationale of the PREDICT-HP study. This study will enrol ∼135 patients with FHP at approximately seven academic medical sites. Participants with a confirmed diagnosis of FHP are followed over 24 months and undergo physical examinations, self-administered questionnaires, chest computed tomography, pulmonary function tests, a 6-min walk test and blood testing for transcriptomic analyses. At each 6-month follow-up visit the study will assess the participants' clinical course and clinical events including hospitalisations and respiratory exacerbations. The PREDICT study has the potential to enhance our ability to predict disease progression and fundamentally advance our understanding of the pathobiology of FHP disease progression.

Effect of Nintedanib in Patients with Progressive Pulmonary Fibrosis in Subgroups with Differing Baseline Characteristics

INTRODUCTION

In the INBUILD trial in patients with progressive pulmonary fibrosis other than idiopathic pulmonary fibrosis (IPF), nintedanib slowed the rate of decline in forced vital capacity (FVC; mL/year) over 52 weeks compared with placebo. We assessed the efficacy of nintedanib across subgroups in the INBUILD trial by baseline characteristics.

METHODS

We assessed the rate of decline in FVC over 52 weeks and time to progression of interstitial lung disease (ILD) (absolute decline from baseline in FVC % predicted > 10%) or death over the whole trial in subgroups based on sex, age, race, body mass index (BMI), time since diagnosis of ILD, FVC % predicted, diffusing capacity of the lungs for carbon monoxide (DLco) % predicted, composite physiologic index (CPI), GAP (gender, age, lung physiology) stage, use of anti-acid therapy and use of disease-modifying antirheumatic drugs (DMARDs) at baseline.

RESULTS

The effect of nintedanib versus placebo on reducing the rate of decline in FVC over 52 weeks was consistent across the subgroups by baseline characteristics analysed. Interaction p values did not indicate heterogeneity in the treatment effect between these subgroups (p > 0.05). Over the whole trial (median follow-up time ∼19 months), progression of ILD or death occurred in similar or lower proportions of patients treated with nintedanib than placebo across the subgroups analysed, with no heterogeneity detected between the subgroups.

CONCLUSIONS

In the INBUILD trial, no heterogeneity was detected in the effect of nintedanib on reducing the rate of ILD progression across subgroups based on demographics, ILD severity or use of anti-acid therapy or DMARDs. These data support the use of nintedanib as a treatment for progressive pulmonary fibrosis.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT02999178.

Fibrosing Progressive Interstitial Lung Disease in Rheumatoid Arthritis: A Multicentre Italian Study

BACKGROUND

The INBUILD study demonstrated the efficacy of nintedanib in the treatment of progressive fibrosing interstitial lung disease different to idiopathic pulmonary fibrosis, including rheumatoid arthritis (RA)-related ILD. Nevertheless, the prevalence of RA-ILD patients that may potentially benefit from nintedanib remains unknown.

OBJECTIVES AND METHODS

The aim of the present multicentre study was to investigate the prevalence and possible associated factors of fibrosing progressive patterns in a cross-sectional cohort of RA-ILD patients.

RESULTS

One hundred and thirty-four RA-ILD patients with a diagnosis of RA-ILD, who were confirmed at high-resolution computed tomography and with a follow-up of at least 24 months, were enrolled. The patients were defined as having a progressive fibrosing ILD in case of a relative decline in forced vital capacity > 10% predicted and/or an increased extent of fibrotic changes on chest imaging in a 24-month period. Respiratory symptoms were excluded to reduce possible bias due to the retrospective interpretation of cough and dyspnea. According to radiologic features, ILD was classified as usual interstitial pneumonia (UIP) in 50.7% of patients, nonspecific interstitial pneumonia in 19.4%, and other patterns in 29.8%. Globally, a fibrosing progressive pattern was recorded in 36.6% of patients (48.5% of patients with a fibrosing pattern) with a significant association to the UIP pattern.

CONCLUSION

We observed that more than a third of RA-ILD patients showed a fibrosing progressive pattern and might benefit from antifibrotic treatment. This study shows some limitations, such as the retrospective design. The exclusion of respiratory symptoms' evaluation might underestimate the prevalence of progressive lung disease but increases the value of results.

Add-on therapy for pulmonary fibrosis, a forthcoming era with implications for practice: the BI 101550 and RELIEF trials

The therapeutic landscape for idiopathic pulmonary fibrosis (IPF) and progressive fibrosing interstitial lung disease (PFILD) is increasingly complex, with add-on antifibrotic options now in clinical trials, or available for patients progressing on first-line therapy in both conditions. Here, we review two recent trials of potential add-on therapeutic options, the BI 101550 and RELIEF trials. BI 101550 was a phase 2 randomised control trial (RCT) of a novel phosphodiesterase-4 inhibitor in patients with IPF, with a primary end-point of change in forced vital capacity (ΔFVC) (in mL) at 12 weeks. The RELIEF trial was a phase 2 RCT in patients with PFILD, with a primary end-point of ΔFVC (absolute % predicted) over 48 weeks. Whilst the BI 101550 and RELIEF trials showed positive results in their primary end-points, the strengths and weaknesses of both trials are discussed with importance for their interpretation and clinical impact. We review current clinical practice in IPF and PFILD and place the BI101550 and RELIEF trial results in context, highlighting advances and problems with antifibrotic therapies.

Commentary on

Richeldi L, et al. Trial of a preferential phosphodiesterase 4B inhibitor for idiopathic pulmonary fibrosis. N Engl J Med 2022; 386: 2178-2187.Behr J, et al. Pirfenidone in patients with progressive fibrotic interstitial lung diseases other than idiopathic pulmonary fibrosis (RELIEF): a double-blind, randomised, placebo-controlled, phase 2b trial. Lancet Respir Med 2021; 9: 476-486.

Impact of ILD-Specific Therapies on Perioperative Course in Patients with Progressive Interstitial Lung Disease Undergoing Lung Transplantation

Immunosuppressants and antifibrotics are currently used to treat patients with various interstitial lung diseases, which may undergo lung transplantation (LTx). The retrospective study aimed to evaluate the potential effects of therapeutic regimen on the perioperative course in patients with idiopathic pulmonary fibrosis (IPF) or progressive pulmonary fibrosis (PPF) undergoing LTx. All patients with IPF and PPF undergoing LTx between January 2014 and December 2021 were included. We retrospectively screened for previous use of immunosuppressants and antifibrotic therapy. We analyzed perioperative courses, short-term outcomes, and safety retrospectively. In total, 286 patients with diagnosis of IPF or PPF were analyzed. According to the treatment regimen before LTx, the study cohort was divided into four groups and compared. No differences between antifibrotic monotherapy, combined antifibrotic and immunosuppressive therapy with regard to postoperative complications were observed. Length of mechanical ventilation was shorter in patients with antifibrotics prior to LTx. Pretreatment with antifibrotic monotherapy and a combination of antifibrotic drugs with immunosuppressive therapy, lower body mass index (BMI) and lower blood loss, were independently associated with primary graft dysfunction grades 0-3 72 hours after LTx (p < 0.001). Finally, patients with antifibrotic monotherapy developed significantly less de novo donor-specific antibodies (DSA) (p = 0.009). Higher intraoperative blood loss, etiology of interstitial lung disease (ILD) and older age were independently associated with shorter survival after LTx. Use of antifibrotic monotherapy and a combination of antifibrotic drugs with immunosuppressive therapy in IPF/PPF patients undergoing LTx, proved to be safe and might lead to beneficial effects after LTx.

Clinical outcomes and risk factors of progressive pulmonary fibrosis in primary Sjögren's syndrome-associated interstitial lung disease

BACKGROUND

To investigate the clinical outcomes and risk factors associated with progressive fibrosing interstitial lung disease (PF-ILD) in patients with primary Sjögren's syndrome-associated interstitial lung disease (pSjS-ILD).

METHODS

During 2015-2021, pSjS patients with ILD were retrospectively identified. Patients were grouped into non-PF-ILD and PF-ILD. Demographics, laboratory data, pulmonary function tests (PFTs), images, survival outcomes were compared between groups.

RESULTS

153 patients with SjS-ILD were reviewed, of whom 68 having primary SjS-ILD (pSjS-ILD) were classified into non-PF-ILD (n = 34) and PF-ILD groups (n = 34). PF-ILD group had persistently lower albumin levels and a smaller decline in immunoglobulin G (IgG) levels at the 3rd month of follow-up. The multivariate logistic regression analysis revealed that persistently low albumin levels were associated with PF-ILD. At the 12th month, the PF-ILD group experienced a smaller increase in FVC and a greater decline in the diffusion capacity of carbon monoxide (DLCO) than at baseline. The 3-year overall survival rate was 91.2%, and PF-ILD group had significantly poorer 3-year overall survival rate than non-PF-ILD group (82.4% vs. 100%, p = 0.011). Poor survival was also observed among female patients with PF-ILD.

CONCLUSIONS

Among patients with pSjS-ILD, the PF-ILD group had poorer 3-year survival outcomes. Persistent lower albumin level might be the risk factor of PF-ILD. Early lung function tests could be helpful for the early detection of PF-ILD.

Nationwide epidemiologic study for fibrosing interstitial lung disease (F-ILD) in South Korea: a population-based study

BACKGROUND

Fibrosing interstitial lung disease (F-ILD) is a major public health concern due to its poor prognosis. Recent clinical evidence shows that antifibrotic approaches such as pirfenidone and nintedanib provide better clinical outcome prediction in idiopathic pulmonary fibrosis (IPF) as well as selected progressive fibrosing ILD (PF-ILD) patients. Having epidemiologic insight into these diseases will be essential for the efficient utilization of these therapeutic resources. This study aimed to estimate the current prevalence, incidence, and mortality of F-ILD classified as idiopathic pulmonary fibrosis (IPF), PF-ILD other than IPF, and non-progressive F-ILD and their temporal trend in Korea.

METHODS

Population-based retrospective cohort study was conducted using the Korean Health Insurance Review and Assessment (HIRA) database (2011-2018). Patients with IPF were identified using ICD-10 code, RID code, and differential diagnosis approach. By leveraging medical records available from claim data and referencing those used in clinical trials, rigorous diagnostic criteria for PF-ILD detection were implemented.

RESULTS

For the past eight years, the prevalence of IPF and PF-ILD has progressively increased, while non-progressive F-ILD has remained stable. IPF, PF-ILD, and non-progressive F-ILD prevalence per 100,000 in 2018 were 16.9, 10.4, and 11.7, respectively. The incidence of IPF in 2018 was more than twice that of 2012. The incidence of PF-ILD in 2018 was 1.5 times higher than that in 2012. In 2018, the mortalites were 10.3% and 12.2% for IPF and PF-ILD, respectively. The mortality rate of PF-ILD was greater than that of IPF in all years. Unclassifiable PF-ILD and rheumatoid arthritis-PF-ILD had the highest proportion and mortality among the PF-ILD subtypes.

CONCLUSION

The prevalence and incidence of IPF and PF-ILD have been steadily increasing in recent years. The mortality rate of PF-ILD remained consistently high and exceeded those of IPF in all years.

Correlation of monocyte counts with clinical outcomes in idiopathic nonspecific interstitial pneumonia

Higher blood monocyte counts are related to worse survival in idiopathic pulmonary fibrosis. However, studies evaluating the association between blood monocyte counts and clinical outcomes of idiopathic nonspecific interstitial pneumonia (iNSIP) are lacking. We evaluated the impact of monocyte counts on iNSIP prognosis. iNSIP patients (n = 126; median age, 60 years; female, n = 64 [50.8%]) diagnosed by surgical lung biopsy were enrolled and categorized into low (monocyte < 600/µL) and high (monocyte ≥ 600/µL) monocyte groups. The median follow-up duration was 53.0 months. After adjusting for age, sex, and smoking history, the annual decline in forced vital capacity (FVC) showed differences between the monocyte groups (P_interaction = 0.006) (low vs. high; - 28.49 mL/year vs. - 65.76 mL/year). The high-monocyte group showed a worse survival rate (P = 0.01) compared to low monocyte group. The 5-year survival rates were 83% and 72% in the low- and high-monocyte groups, respectively. In the Cox-proportional hazard analysis, older age, male sex, low baseline FVC, and diffusing capacity of the lung for carbon monoxide were independent risk factors for mortality. However, monocyte count (Hazard ratio 1.61, P = 0.126) was not an independent prognostic factor. Although high monocyte count might be associated with faster lung function decline, it could not independently predict survival in iNSIP.

The roles of long noncoding RNA-mediated macrophage polarization in respiratory diseases

Macrophages play an essential role in maintaining the normal function of the innate and adaptive immune responses during host defence. Macrophages acquire diverse functional phenotypes in response to various microenvironmental stimuli, and are mainly classified into classically activated macrophages (M1) and alternatively activated macrophages (M2). Macrophage polarization participates in the inflammatory, fibrotic, and oncogenic processes of diverse respiratory diseases by changing phenotype and function. In recent decades, with the advent of broad-range profiling methods such as microarrays and next-generation sequencing, the discovery of RNA transcripts that do not encode proteins termed "noncoding RNAs (ncRNAs)" has become more easily accessible. As one major member of the regulatory ncRNA family, long noncoding RNAs (lncRNAs, transcripts >200 nucleotides) participate in multiple pathophysiological processes, including cell proliferation, differentiation, and apoptosis, and vary with different stimulants and cell types. Emerging evidence suggests that lncRNAs account for the regulation of macrophage polarization and subsequent effects on respiratory diseases. In this review, we summarize the current published literature from the PubMed database concerning lncRNAs relevant to macrophage polarization and the underlying molecular mechanisms during the occurrence and development of respiratory diseases. These differentially expressed lncRNAs are expected to be biomarkers and targets for the therapeutic regulation of macrophage polarization during disease development.

Suspected Interstitial Lung Disease in COPDGene Study

Rationale: Although interstitial lung abnormalities (ILA), specific patterns of incidentally-detected abnormal density on computed tomography, have been associated with abnormal lung function and increased mortality, it is unclear if a subset with incidental interstitial lung disease (ILD) accounts for these adverse consequences. Objectives: To define the prevalence and risk factors of suspected ILD and assess outcomes. Methods: Suspected ILD was evaluated in the COPDGene (Chronic Obstructive Pulmonary Disease Genetic Epidemiology) study, defined as ILA and at least one additional criterion: definite fibrosis on computed tomography, FVC less than 80% predicted, or DLCO less than 70% predicted. Multivariable linear, longitudinal, and Cox proportional hazards regression models were used to assess associations with St. George's Respiratory Questionnaire, 6-minute-walk test, supplemental oxygen use, respiratory exacerbations, and mortality. Measurements and Main Results: Of 4,361 participants with available data, 239 (5%) had evidence for suspected ILD, whereas 204 (5%) had ILA without suspected ILD. In multivariable analyses, suspected ILD was associated with increased St. George's Respiratory Questionnaire score (mean difference [MD], 3.9 points; 95% confidence interval [CI], 0.6-7.1; P = 0.02), reduced 6-minute-walk test (MD, -35 m; 95% CI, -56 m to -13 m; P = 0.002), greater supplemental oxygen use (odds ratio [OR], 2.3; 95% CI, 1.1-5.1; P = 0.03) and severe respiratory exacerbations (OR, 2.9; 95% CI, 1.1-7.5; P = 0.03), and higher mortality (hazard ratio, 2.4; 95% CI, 1.2-4.6; P = 0.01) compared with ILA without suspected ILD. Risk factors associated with suspected ILD included self-identified Black race (OR, 2.0; 95% CI, 1.1-3.3; P = 0.01) and pack-years smoking history (OR, 1.2; 95% CI, 1.1-1.3; P = 0.0005). Conclusions: Suspected ILD is present in half of those with ILA in COPDGene and is associated with exercise decrements and increased symptoms, supplemental oxygen use, severe respiratory exacerbations, and mortality.

Frequency, proportion of PF-ILD, and prognostic factors in patients with acute exacerbation of ILD related to systemic autoimmune diseases

BACKGROUND

Acute exacerbation (AE) of systemic autoimmune disease-related interstitial lung diseases (SAID-ILD) is less common than AE of idiopathic pulmonary fibrosis (IPF) and the details of AE-SAID-ILD have not been elucidated, but the prognosis is similarly devastating. This study was undertaken to determine the incidences of AE-ILD in each SAID and to elucidate the proportion of progressive fibrosing (PF)-ILD in AE-SAID-ILD.

METHODS

We retrospectively analysed data for patients with SAID-ILD who were diagnosed and observed at our hospital between 1999 and 2020.

RESULTS

Two hundred and thirty-two patients with SAID-ILD were enrolled, with a mean observation period of 100.2 months. AE-SAID-ILD was found in 25 patients (10.78%), mainly in patients with RA (17 patients, 68%) and elderly male patients with a smoking history. The overall incidence of AE-SAID-ILD was 1.29%/person-year, and the incidence for each SAID was as follows: RA 2.193, microscopic polyarteritis (MPA) 3.203, systemic sclerosis (SSc) 2.277, primary Sjögren syndrome 0.426, and polymyositis/dermatomyositis 0.222. The incidence of AE of RA/MPA/SSc-ILD was significantly higher than that of other AE-SAID-ILD (p < 0.001). Five of 25 patients (20%) fulfilled the criteria for PF-ILD. The 90-day survival rate was 48.0%, and a higher neutrophil count at AE (HR 13.27, 95%CI 2.447-246, p = 0.001) and early commencement of long-duration direct haemoperfusion with a polymyxin B-immobilised fibre column (HR 0.105, 95%CI 0.005-0.858, p = 0.035) were significant prognostic factors.

CONCLUSIONS

The incidence of AE-SAID-ILD was significantly higher in patients with RA, MPA, or SSc than in patients with other SAID. Furthermore, even in patients with AE-SAID-ILD, the proportion of PF-ILD just before AE was not high (20%).

The significance of elevated tumor markers among patients with interstitial lung diseases

The clinical implication of using serum tumor markers in patients with interstitial lung disease (ILD) is inconclusive. In this retrospective study, we analyzed the data of 1176 subjects (294 with ILDs and 882 healthy controls). Eligible patients were who had at least one or more available tumor marker results [carbohydrate antigen (CA) 19-9, CA 125, and carcinoembryonic antigen (CEA)] with no evidence of malignancies or other benign diseases that could be related to the increasing concentration of the values. The healthy controls selected from a health screening program were also screened for the presence of active cancer, and matched at a ratio of 1:3 with age and sex. The proportion of patients with abnormal values in the ILD group (121, idiopathic pulmonary fibrosis (IPF); 173, non-IPF-ILDs) was higher than in the matched control group (CEA, 21.5% vs. 5.5%; CA 19-9, 27.9% vs. 4.0%; CA 125, 36.4% vs. 2.0%). In the multivariable analysis, higher CEA levels were associated with shorter survival after adjusting for age, sex, lung function, and ILD subtypes (hazard ratio: 2.323, 95% confidence interval: 1.271–4.248, P = 0.006). In subgroup analysis, CEA remained a prognostic factor in patients with non-IPF-ILDs, but not in those with IPF.

Guidelines of the Polish Respiratory Society on the Diagnosis and Treatment of Progressive Fibrosing Interstitial Lung Diseases Other than Idiopathic Pulmonary Fibrosis

The recommendations were developed as answers to previously formulated questions concerning everyday diagnostic and therapeutic challenges. They were developed based on a review of the current literature using the GRADE methodology. The experts suggest that PF-ILD be diagnosed based on a combination of different criteria, such as the aggravation of symptoms, progression of radiological lesions, and worsening of lung function test parameters. The experts recommend a precise diagnosis of an underlying disease, with serological testing for an autoimmune disease always being included. The final diagnosis should be worked out by a multidisciplinary team (MDT). Patients with an interstitial lung disease other than IPF who do not meet the criteria for the progressive fibrosis phenotype should be monitored for progression, and those with systemic autoimmune diseases should be regularly monitored for signs of interstitial lung disease. In managing patients with interstitial lung disease associated with autoimmune diseases, an opinion of an MDT should be considered. Nintedanib rather than pirfenidon should be introduced in the event of the ineffectiveness of the therapy recommended for the treatment of the underlying disease, but in some instances, it is possible to start antifibrotic treatment without earlier immunomodulatory therapy. It is also admissible to use immunomodulatory and antifibrotic drugs simultaneously. No recommendations were made for or against termination of anti-fibrotic therapy in the case of noted progression during treatment of a PF-ILD other than IPF. The experts recommend that the same principles of non-pharmacological and palliative treatment and eligibility for lung transplantation should be applied to patients with an interstitial lung disease other than IPF with progressive fibrosis as in patients with IPF.

Epidemiology and real-life experience in progressive pulmonary fibrosis

PURPOSE OF REVIEW

Idiopathic pulmonary fibrosis (IPF), characterized by relentless disease progression from the time of diagnosis, is part of a larger group of chronic fibrosing interstitial lung diseases (ILDs). A proportion of patients with non-IPF ILDs may develop, despite conventional treatment, a progressive pulmonary fibrosis (PPF), also referred to as ILD with a progressive fibrosing phenotype (PF-ILD). These patients experience worsening of respiratory symptoms, decline in lung function, and early mortality. The goal of this review is to describe the epidemiology and recent real-life cohorts of PF-ILD, with implications for management.

RECENT FINDINGS

The relatively new concept of PF-ILD has aroused active clinical research over the past years. To understand risk factors for progression and the real burden of the disease is crucial to improve management. In the last 2 years, different cohort studies have addressed these questions. They showed that almost one-third of the non-IPF fibrotic ILD patients develop PF-ILD or PPF.

SUMMARY

Emerging data show similarities in prognosis between patients with IPF or with non-IPF PF-ILD patients. Early detection and appropriate treatment of this group of patients is a priority. Further research is needed to identify risk factors of progression, to clarify the assessment of progression in clinical practice, for a better management of patients with PF-ILD in a real-world setting.

Reticulation pattern without honeycombing on high-resolution CT is associated with the risk of disease progression in interstitial lung diseases

Background

The disease course of idiopathic pulmonary fibrosis (IPF) is progressive and occasionally, other types of interstitial lung disease (ILD) may progress similarly to IPF. This study aimed to evaluate risk factors for disease progression within 24 months in patients with various ILDs.

Methods

This prospective study obtained 97 patients with a suspected ILD who underwent a transbronchial lung cryobiopsy. The extent of several high-resolution computed tomography (HRCT) patterns was assessed. Due to the inclusion criteria the study population presented a low extent of honeycombing and definite usual interstitial pneumonia (UIP) pattern on HRCT suggesting an early stage of ILD. Disease progression within 24 months despite treatment was defined as a relative decline of ≥ 10% in forced vital capacity (FVC), or a relative decline in FVC of ≥ 5% and one of the three additional criteria: (1) a decline in diffusion capacity to carbon monoxide (DLCO) ≥ 15%; (2) increased fibrosis on HRCT; (3) progressive symptoms, or progressive symptoms and increased fibrosis on HRCT. The same definition was utilized in patients with IPF and other ILDs. Risk factors for disease progression were evaluated in a multivariable logistic regression model.

Results

Disease progression was revealed in 52% of the patients with ILD, 51% of the patients with IPF, and 53% of the patients with other types of ILD. A high extent of reticulation on HRCT (Odds ratio [OR] 3.11, 95% Confidence interval [CI] 1.21–7.98, P = 0.019) and never smoking (OR 3.11, CI 1.12–8.63, P = 0.029) were associated with disease progression whereas platelet count (OR 2.06 per 100 units increase, CI 0.96–4.45, P = 0.065) did not quite reach statistical significance.

Conclusion

Higher extent of reticulation on HRCT and never smoking appeared to associate with the risk of disease progression within 24 months in ILD patients without honeycombing. Approximately half of the patients with ILD revealed disease progression, and similar proportions were observed in patients with IPF and in other types of ILD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02105-9.

Current perspective of progressive-fibrosing interstitial lung disease

Interstitial lung disease (ILD) is a parenchymal lung disease and restrictive disorder that presents as diffuse infiltrative shadows. The initial diagnosis of ILD is important because management strategies depend on the disease pathogenesis. Connective-tissue disease (CTD)-associated ILD including rheumatoid arthritis (RA), systemic sclerosis (SSc) requires a thorough evaluation of chronic respiratory symptoms such as non-productive cough and exertional dyspnea, as well as physical findings. Moreover, myeloperoxidase-positive anti-neutrophilic cytoplasmic antibody (MPO-ANCA)-associated vasculitis with ILD also shows disease progression. In CTD-associated ILD, the first-line treatment is anti-inflammatory drugs such as prednisolone or immunosuppressants. In hypersensitivity pneumonitis (HP), detailed environmental history-taking is crucial. Therefore, systematic standardized questionnaires are needed. However, the causative antigens are often not identified in daily clinical practice. When an antigen is identified or suspected, the first action is avoidance. If antigen avoidance does not contribute to clinical improvement, anti-inflammatory drugs such as prednisolone might be introduced. Regarding sarcoidosis, while most patients do not require treatment for lung involvement, some need anti-inflammatory drugs or immunosuppressants. Additionally, steroid treatment should be considered for the critical status of extrapulmonary sarcoidosis including cardiac, neurogenic and ocular sarcoidosis. Once starting treatment for ILD, multi-dimensional approaches are applied, including symptom tracking, chest imaging, pulmonary function test (PFT), and 6-min walking test. Recently, the concept of progressive-fibrosing interstitial lung disease (PF-ILD) has been proposed as a new disease entity. The definition of PF-ILD includes symptom progression, PFT decline, and extension of chest high-resolution computed tomography (HRCT) findings. This mini-review describes the background, definition, clinical characteristics, management, and challenges of PF-ILD.

Prognostic Predictive Characteristics in Patients With Fibrosing Interstitial Lung Disease: A Retrospective Cohort Study

Background: Limited data are available regarding the entire spectrum of interstitial lung disease with a progressive fibrosing feature. We investigated the prevalence and prognostic predictive characteristics in patients with PF-ILD.

Methods: This retrospective cohort study included patients with fibrosing ILD who were investigated between 1 January 2015 and 30 April 2021. We recorded clinical features and outcomes to identify the possible risk factors for fibrosing progression as well as mortality.

Results: Of the 579 patients with fibrosing ILD, 227 (39.21%) met the criteria for progression. Clubbing of fingers [odds ratio (OR) 1.52, 95% confidence interval (CI) 1.03 to 2.24, p = 0.035] and a high-resolution computed tomography (HRCT)-documented usual interstitial pneumonia (UIP)-like fibrotic pattern (OR 1.95, 95% CI 1.33 to 2.86, p = 0.001) were risk factors for fibrosis progression. The mortality was worse in patients with PF with hypoxemia [hazard ratio (HR) 2.08, 95% CI 1.31 to 3.32, p = 0.002], in those with baseline diffusion capacity of the lung for carbon monoxide (DLCO) % predicted &lt;50% (HR 2.25, 95% CI 1.45 to 3.50, p &lt; 0.001), or in those with UIP-like fibrotic pattern (HR 1.68, 95% CI 1.04 to 2.71, p &lt; 0.001).

Conclusion: Clubbing of fingers and an HRCT-documented UIP-like fibrotic pattern were more likely to be associated with progressive fibrosing with varied prevalence based on the specific diagnosis. Among patients with progressive fibrosing, those with hypoxemia, lower baseline DLCO% predicted, or UIP-like fibrotic pattern showed poor mortality.

Pulmonary fibrosis associated with rheumatoid arthritis: from pathophysiology to treatment strategies

INTRODUCTION

Rheumatoid arthritis (RA) is the most common inflammatory autoimmune disease, characterised by symmetric destructive arthritis and synovitis. Lung involvement is frequent, including in the form of interstitial lung disease (ILD). RA-ILD often presents with a radiologic and pathologic pattern of usual interstitial pneumonia, similar to idiopathic pulmonary fibrosis, highlighting the similarities between the two diseases, but other patterns and pathological associations are described.

AREAS COVERED

This article reviews the pathogenesis of pulmonary fibrosis in the setting of rheumatoid arthritis as well as the current and future therapeutic options.

EXPERT OPINION

Pulmonary fibrosis in the setting of RA-ILD is an example of genotype-environment interaction and involves multiple mechanisms including autoimmunity, inflammation and fibrogenesis. Despite that ILD conveys most of the exceeding mortality in RA patients, there are no official guidelines for the management of RA-ILD. Attention should be paid to potential lung toxicity of RA treatment even though some of them might help stabilise the ILD. Current standard of care is often composed of glucocorticoids that may be associated with immunosuppressive therapy. Following the approval of antifibrotic therapy for ILDs with a progressive fibrosing phenotype, current works are evaluating the benefit of such treatment in RA-ILD.

Prevalence and prognosis of chronic fibrosing interstitial lung diseases with a progressive phenotype

BACKGROUND AND OBJECTIVE

The development of clinically progressive fibrosis complicates a wide array of interstitial lung diseases (ILDs). However, there are limited data regarding its prevalence and prognosis.

METHODS

We analysed consecutive patients seen for initial evaluation of a fibrosing form of ILD (FILD). Patients were evaluated for evidence of progressive fibrosis over the first 24 months of follow-up. We defined a progressive phenotype as the presence of at least one of the following: a relative decline in forced vital capacity (FVC) of ≥10%; a relative decline in FVC of ≥5%-<10% with a relative decline in diffusing capacity of the lung for carbon monoxide of ≥15%, increased fibrosis on HRCT or progressive symptoms.

RESULTS

Eight hundred and forty-four patients (397 with idiopathic pulmonary fibrosis [IPF] and 447 non-IPF FILD) made up the final analysis cohort. Three hundred and fifty-five patients (42.1%) met the progressive phenotype criteria (59.4% of IPF patients and 26.6% of non-IPF FILD patients, p <0.01). In both IPF and non-IPF FILD, transplantation-free survival differed between patients with a progressive phenotype and those without (p <0.01). Multivariable analysis showed that a progressive phenotype was an independent predictor of transplantation-free survival (hazard ratio [HR]: 3.36, 95% CI: 2.68-4.23, p <0.01). Transplantation-free survival did not differ between non-IPF FILD with a progressive phenotype and IPF (HR: 1.12, 95% CI: 0.85-1.48, p = 0.42).

CONCLUSION

Over one-fourth of non-IPF FILD patients develop a progressive phenotype compared to approximately 60% of IPF patients. The survival of non-IPF FILD patients with a progressive phenotype is similar to IPF.

Molecular Mechanisms and Cellular Contribution from Lung Fibrosis to Lung Cancer Development

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease (ILD) of unknown aetiology, with a median survival of 2-4 years from the time of diagnosis. Although IPF has unknown aetiology by definition, there have been identified several risks factors increasing the probability of the onset and progression of the disease in IPF patients such as cigarette smoking and environmental risk factors associated with domestic and occupational exposure. Among them, cigarette smoking together with concomitant emphysema might predispose IPF patients to lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer development. To this purpose, IPF and LC share several cellular and molecular processes driving the progression of both pathologies such as fibroblast transition proliferation and activation, endoplasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target molecular pathway. In this review our aim is to describe the updated studies on common cellular and molecular mechanisms between IPF and lung cancer, knowledge of which might help to find novel therapeutic targets for this disease combination.