Acute exacerbation of idiopathic pulmonary fibrosis associated with air pollution exposure

Lag analysis of the effect of air pollution on orthopedic postoperative infection in Hebei Province and Xinjiang Uygur Autonomous Region

To investigate the population distribution characteristics of hospitalized patients with postoperative fracture infections in Hebei Province and Xinjiang Uygur Autonomous Region, and to analyze the effects of air pollutants on postoperative fracture infections within the two regions. Data on orthopedic postoperative infection cases were retrospectively collected from representative hospitals in Hebei Province and the Xinjiang Uygur Autonomous Region from 2018 to 2022. Their distribution characteristics were analyzed using descriptive epidemiological methods. The lagged effects of air pollutants on postoperative infections were also evaluated using distributed lag nonlinear modeling, combined with air quality data from the same period. The rate of postoperative infections after orthopedic surgery in the Xinjiang Uygur Autonomous Region (3.06%) was significantly higher than that in the Hebei Region (0.47%) in this study. A total of 1338 patients with postoperative infections were collected from the two regions, with a mean age of 51.41 ± 17.34 years. The most affected age group was 41-60 years (521 cases, 39%), and there was a male predominance (875 cases, 65.40%). Using the air pollutant P50 as the reference concentration, the greatest cumulative 3-day increase in the risk of postoperative infection was observed for each 0.1 mg/m3 increase in CO concentration (RR = 1.069, 95% CI 1.029, 1.110). The greatest cumulative 12-day effect was observed for each 10 μg/m3 increase in NO2 concentration (RR = 1.67, 95% CI 1.369, 2.037). CO and NO2 showed reduced effects at very low concentrations and elevated effects at very high concentrations. The rate of postoperative infections after orthopedic surgery in the Xinjiang Uygur Autonomous Region was significantly higher than that in the Hebei Region. In Xinjiang, postoperative infections were predominantly observed in males aged 41-60 years. Exposure to air pollutants such as CO and NO2 increased the risk of postoperative orthopedic infections to varying degrees, with both short-term and cumulative lagged effects.

Gaseous Air Pollutants and Lung Function in Fibrotic Interstitial Lung Disease (fILD): Evaluation of Different Spatial Analysis Approaches

Gaseous pollutants such as CO, NO2, O3, and SO2 are linked to adverse clinical outcomes in patients with fibrotic interstitial lung diseases (fILDs), particularly idiopathic pulmonary fibrosis. However, the effect of various exposure estimation methods on these findings remains unclear. This study aims to evaluate three spatial approaches─nearest neighbor (NN), inverse distance weighting (IDW), and Kriging─for estimating gaseous pollutant exposures and to assess how these methods affect health outcome estimates in fILD patients. A 10-fold cross-validation showed that Kriging had the lowest prediction error compared to NN and IDW, with RMSE for CO = 0.43 ppm (11%), O3 = 5.9 ppb (14%), SO2 = 2.7 ppb (12%), and NO2 = 7.6 ppb (9%), respectively. Kriging also excelled over other methods across wide spatial and temporal ranges, showing the highest spatial R2 for CO and O3 and the highest temporal R2 for SO2 and NO2. In a large cohort of patients with fILD, higher levels of CO, SO2, and NO2 exposure were associated with lower pulmonary function. The magnitude of association and its precision were higher in SO2 and CO estimated by the Kriging method. This study underscores Kriging as a robust method for estimating gaseous pollutant levels and offers valuable insights for future epidemiological studies.

Ozone-induced lung injury and inflammation: Pathways and therapeutic targets for pulmonary diseases caused by air pollutants

Exposure to ambient Ozone (O3) air pollution directly causes by its oxidative properties, respiratory epithelial cell injury, and cell death, which promote inflammation and hyperreactivity, posing a significant public health concern. Recent clinical and experimental studies have made strides in elucidating the mechanisms underlying O3-induced epithelial cell injury, inflammation, and airway hyperreactivity, which are discussed herein. The current data suggest that O3-induced oxidative stress is a central event-inducing oxeiptotic cell death pathway. O3-induced epithelial barrier damage and cell death, triggering the release of alarmins and damage-associated molecular patterns (DAMPs), with subsequent endogenous activation of Toll-like receptors (TLRs), DNA sensing pathways, and inflammasomes, activating interleukin-1-Myd88 inflammatory pathway with the production of a range of chemokines and cytokines. This cascade orchestrates lung tissue-resident cell activation in response to O3 in leukocyte and non-leukocyte populations, driving sterile innate immune response. Chronic inflammatory response to O3, by repeated exposures, supports a mixed phenotype combining asthma and emphysema, in which their exacerbation by other particulate pollutants potentially culminates in respiratory failure. We use data from lung single-cell transcriptomics to map genes of O3-damage sensing and signaling pathways to lung cells and thereby highlight potential hotspots of O3 responses. Deeper insights into these pathological pathways might be helpful for the identification of novel therapeutic targets and strategies.

Correlation analysis between the prevalence of common respiratory pathogens and exposure to ambient air pollutants in Central China, 2014-2022

Background

Whether ambient air pollutants affect the transmission of respiratory pathogens in central Wuhan is unknown. So, we conducted a series of statistical analyses to discover the correlation between the two.

Methods

We enrolled a total of 47,668 outpatient and hospitalized patients who underwent IgM antibody tests for nine types of respiratory pathogens, namely, Legionella pneumophila type 1 (LP1), Mycoplasma pneumoniae (MP), Q fever rickettsia (QFR), Chlamydia pneumoniae (CP), adenovirus (ADV), respiratory syncytial virus (RSV), influenza virus A (FluA), influenza virus B (FluB), and parainfluenza virus (PIVs) between January 2014 and December 2022. Monthly measurements were taken for specific air pollutants, including fine particulate matter 2.5 (PM2.5), inhalable particulate matter 10 (PM10), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) at the same periods. The association between different respiratory pathogen infections and major air pollutants was primarily analyzed using Spearman's correlation analysis.

Conclusion

MP, LP1, and FluB are correlated with respiratory infections and have been identified as potential causative agents. Elevated levels of O3 were found to augment the incidence of MP infection. We first discovered the positive correlation between SO2 and ADV infection and between CO and LP1 infection. The presence of air pollutants in Wuhan showed a significant correlation with respiratory pathogens, and elevated levels of air pollution facilitated their transmission to individuals.

The impact of climate change on respiratory health: current understanding and knowledge gaps

PURPOSE OF REVIEW

To present an overview of the impact of climate change upon human respiratory health.

RECENT FINDINGS

Climate change is directly impacting air quality. Particulate matter clearly increases mortality rates. Ozone, a longstanding suspect in climate-related injury, turns out not to have the major impact that had been projected at current levels of exposure. The key factors in global warming have been clearly identified, but while these factors collectively cause deleterious changes, a close look at the literature shows that it is unclear to what extent each factor individually is a driver of a specific process. This article summarizes some of those studies.

SUMMARY

A better understanding of which components of climate change most impact human health is needed in order to re-define environmental standards. PM 2.5 needs to be broken down by chemical composition to study the differential impacts of different sources of PM 2.5 . The detection and study of climate-related changes in respiratory infectious diseases is in a state of relative infancy.

Prevalence and Predictors of Response to Antifibrotics in Long-Term Survivors with Idiopathic Pulmonary Fibrosis

PURPOSE

The natural history of IPF remains unpredictable despite antifibrotic treatment. In addition, some patients discontinue treatment due to the occurrence of adverse events. To date, no data exist on either the effect of long-term treatment or predictors of treatment response. In the present study, we aim to evaluate the functional trajectory of IPF patients treated with antifibrotics for at least three years and to establish predictors of treatment response.

METHODS

This multicenter study enrolled long-term survivors IPF patients provided they had stopped treatment for no longer than one month during at least three-year study period. Based on the absolute decline of FVC%predicted (pred.) observed during the 3-year treatment and normalized per year, patients were defined as progressors (≥ 5%) or non-progressors (< 5%).

RESULTS

We identify 172 IPF patients who completed three years of antifibrotic treatment with no interruption. The 27% of these IPF patients progressed despite complete adherence to treatment. Progressors were more likely to be non-smokers compared to non-progressors, with higher occurrence of diarrhea and with a more preserved lung function at diagnosis. FVC %pred. and liters at diagnosis, a greater FVC decline in the 1-st year of follow up, being non-smokers, and complaining of diarrhea over treatment are independent predictors of progression.

CONCLUSION

Almost one third of IPF patients adherent to three years of antifibrotics experience progression. A functional decline at first year of treatment despite preserved lung function at diagnosis, non-smoking status, and occurrence of diarrhea over treatment are independent predictors of disease progression.

Pathophysiology of small airways in idiopathic pulmonary fibrosis (IPF): the silent zone

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease characterized by distorted alveolar structure and reduced lung compliance, and impaired ventilation-perfusion. Small airway disease (SAD) is  often termed a 'quietzone' due to its asymptomatic nature. Around 30-40% of IPF patients exhibit SAD, which is associated with worse prognosis, higher fibrosis and emphysema scores, and elevated mortality risk. We used PubMed and Google Scholar for literature search.

AREAS COVERED

This review explores the pathophysiology of small airways in IPF, focusing on 1. Risk factors, including age, gender, smoking and occupational dust exposure, and ozone. 2. Diagnostic challenges: SAD is difficult to detect through traditional spirometry or high-resolution computed tomography  imaging due to resolution limitations.  3. Early physiological changes of small airways include airway wall thickening, lumen distortion, and reduced terminal bronchioles, preceding microscopic fibrosis, occurs in the early process of IPF. 4. Pathological mechanisms: The review examines the underlying mechanisms driving small airway disease in IPF.

EXPERT OPINION

A comprehensive approach is essential to improve the understanding and management of SAD in IPF. Priorities include identifying therapeutic targets, advanced imaging and functional assessments. Forced oscillation technique should be introduced for early detection for small airway abnormalities in IPF.

The potential lipid biomarker 5-HETE for acute exacerbation identified by metabolomics in patients with idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVE

Acute exacerbation (AE) is often the fatal complication of idiopathic pulmonary fibrosis (IPF). Emerging evidence indicates that metabolic reprogramming and dysregulation of lipid metabolism are distinctive characteristics of IPF. However, the lipid metabolic mechanisms that underlie the pathophysiology of AE-IPF remain elusive.

METHODS

Serum samples for pilot study were collected from 34 Controls, 37 stable IPF (S-IPF) cases and 41 AE-IPF patients. UHPLC-MS/MS was utilized to investigate metabolic variations and identify lipid biomarkers in serum. ELISA, quantitative PCR and western blot were employed to validate the identified biomarkers.

RESULTS

There were 32 lipid metabolites and 5 lipid metabolism pathways enriched in all IPF patients compared to Controls. In AE-IPF versus S-IPF, 19 lipid metabolites and 12 pathways were identified, with 5-hydroxyeicosatetraenoic Acid (5-HETE) significantly elevated in AE-IPF. Both in internal and external validation cohorts, the serum levels of 5-HETE were significantly elevated in AE-IPF patients compared to S-IPF subjects. Consequently, the indicators related to 5-HETE in lipid metabolic pathway were significantly changed in AE-IPF patients compared with S-IPF cases in the lung tissues. The serum level of 5-HETE was significantly correlated with the disease severity (CT score and PaO2/FiO2 ratio) and survival time. Importantly, the receiver operating characteristic (ROC) curve, Kaplan-Meier analysis and Multivariate Cox regression analysis demonstrated that 5-HETE represents a promising lipid biomarker for the diagnosis and prognosis of AE-IPF.

CONCLUSION

Our study highlights lipid reprogramming as a novel therapeutic approach for IPF, and 5-HETE may be a potential biomarker of AE-IPF patients.

Progressive lung fibrosis: reprogramming a genetically vulnerable bronchoalveolar epithelium

Idiopathic pulmonary fibrosis (IPF) is etiologically complex, with well-documented genetic and nongenetic origins. In this Review, we speculate that the development of IPF requires two hits: the first establishes a vulnerable bronchoalveolar epithelium, and the second triggers mechanisms that reprogram distal epithelia to initiate and perpetuate a profibrotic phenotype. While vulnerability of the bronchoalveolar epithelia is most often driven by common or rare genetic variants, subsequent injury of the bronchoalveolar epithelia results in persistent changes in cell biology that disrupt tissue homeostasis and activate fibroblasts. The dynamic biology of IPF can best be contextualized etiologically and temporally, including stages of vulnerability, early disease, and persistent and progressive lung fibrosis. These dimensions of IPF highlight critical mechanisms that adversely disrupt epithelial function, activate fibroblasts, and lead to lung remodeling. Together with better recognition of early disease, this conceptual approach should lead to the development of novel therapeutics directed at the etiologic and temporal drivers of lung fibrosis that will ultimately transform the care of patients with IPF from palliative to curative.

Air Pollution and Interstitial Lung Disease

This review article explores the multifaceted relationship between air pollution and interstitial lung diseases (ILDs), particularly focusing on idiopathic pulmonary fibrosis, the most severe form of fibrotic ILD. Air pollutants are mainly composed of particulate matter, ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO), and sulfur dioxide (SO2). They are recognized as risk factors for several respiratory diseases. However, their specific effects on ILDs and related mechanisms have not been thoroughly studied yet. Emerging evidence suggests that air pollutants may contribute to the development and acute exacerbation of ILDs. Longitudinal studies have indicated that air pollution can adversely affect the prognosis of disease by decreasing lung function and increasing mortality. Lots of in vitro, in vivo , and epidemiologic studies have proposed possible mechanisms linking ILDs to air pollution, including inflammation and oxidative stress induced by exposure to air pollutants, which may induce mitochondrial dysfunction, promote cellular senescence, and disrupt normal epithelial repair processes. Despite these findings, effective interventions to mitigate effects of air pollution on ILD are not well established yet. This review emphasizes the urgent need to address air pollution as a key environmental risk factor for ILDs and calls for further studies to clarify its effects and develop preventive and therapeutic strategies.

Pathology of idiopathic pulmonary fibrosis with particular focus on vascular endothelium and epithelial injury and their therapeutic potential

Idiopathic pulmonary fibrosis (IPF) remains a challenging disease with no drugs available to change the trajectory. It is a condition associated with excessive and highly progressive scarring of the lungs with remodelling and extracellular matrix deposition. It is a highly "destructive" disease of the lungs. The diagnosis of IPF is challenging due to continuous evolution of the disease, which also makes early interventions very difficult. The role of vascular endothelial cells has not been explored in IPF in great detail. We do not know much about their contribution to arterial or vascular remodelling, extracellular matrix changes and contribution to pulmonary hypertension and lung fibrosis in general. Endothelial to mesenchymal transition appears to be central to such changes in IPF. Similarly, for epithelial changes, the process of epithelial to mesenchymal transition seem to be the key both for airway epithelial cells and type-2 pneumocytes. We focus here on endothelial and epithelial cell changes and its contributions to IPF. In this review we revisit the pathology of IPF, mechanistic signalling pathways, clinical definition, update on diagnosis and new advances made in treatment of this disease. We discuss ongoing clinical trials with mode of action. A multidisciplinary collaborative approach is needed to understand this treacherous disease for new therapeutic targets.

The immune mechanisms of acute exacerbations of idiopathic pulmonary fibrosis

Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) are the leading cause of mortality among patients with IPF. There is still a lack of effective treatments for AE-IPF, resulting in a hospitalization mortality rate as high as 70%-80%. To reveal the complicated mechanism of AE-IPF, more attention has been paid to its disturbed immune environment, as patients with IPF exhibit deficiencies in pathogen defense due to local immune dysregulation. During the development of AE-IPF, the classical stimulatory signals in adaptive immunity are inhibited, while the nonclassical immune reactions (Th17) are activated, attracting numerous neutrophils and monocytes to lung tissues. However, there is limited information about the specific changes in the immune response of AE-IPF. We summarized the immune mechanisms of AE-IPF in this review.

Inhalation exposure to chemicals, microbiota dysbiosis and adverse effects on humans

As revealed by culture-independent methodologies, disruption of the normal lung microbiota (LM) configuration (LM dysbiosis) is a potential mediator of adverse effects from inhaled chemicals. LM, which consists of microbiota in the upper and lower respiratory tract, is influenced by various factors, including inter alia environmental exposures. LM dysbiosis has been associated with multiple respiratory pathologies such as asthma, lung cancer, idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). Chemically-induced LM dysbiosis appears to play significant roles in human respiratory diseases, as has been shown for some air pollutants, cigarette smoke and some inhalable chemical antibiotics. Lung microbiota are also linked with the central nervous system (CNS) in the so-called lung-brain axis. Inhaled chemicals that undergo mucociliary clearance may be linked to respiratory conditions through gut microbiota (GM) dysbiosis in the so-called Gut-Lung axis. However, current linkages of various disease states to LM appears to be associative, with causal linkages requiring further studies using more robust approaches, methods and techniques that are different from those applied in studies involving (GM). Most importantly, the sampling techniques determine the level of risk of cross contamination. Furthermore, the development of continuous or semi-continuous systems designed to replicate the lung microbiome will go a long way to further LM dysbiosis studies. These challenges notwithstanding, the preponderance of evidence points to the significant role of LM-mediated chemical toxicity in human disease and conditions.

Impact of environmental air pollution on respiratory health and function

Environmental air pollution presents a considerable risk to global respiratory health. If critical levels are exceeded, inhaled pollutants can lead to the development of respiratory dysfunction and provoke exacerbation in those with pre-existing chronic respiratory disease. Over 90% of the global population currently reside in areas where environmental air pollution is considered excessive-with adverse effects ranging from acute airway irritation to complex immunomodulatory alterations. This narrative review provides an up-to-date perspective concerning the impact of environmental air pollution on respiratory health and function and describes the underpinning mechanisms that contribute to the development and progression of chronic respiratory disease.

Association between high levels of nitrogen dioxide and increased cumulative incidence of lung cancer in patients with idiopathic pulmonary fibrosis

BACKGROUND

Lung cancer is a fatal complication of idiopathic pulmonary fibrosis (IPF) with a poor prognosis. However, the association between individual exposure to air pollutants and lung cancer development in patients with IPF is unknown. This study aimed to assess the effect of individual exposure to nitrogen dioxide (NO2) on lung cancer development in patients with IPF.

METHODS

We enrolled 1085 patients from an IPF cohort in the Republic of Korea (mean age 65.6 years, males 80.6%). We estimated individual-level long-term exposures to NO2 at the patients' residential addresses using a national-scale exposure prediction model based on data from air quality regulatory monitoring stations. To evaluate the association between NO2 levels and lung cancer development in IPF, we used an individual- and area-level covariates adjusted model as our primary model.

RESULTS

The estimated average annual NO2 concentration was 23.1 ppb. During a median follow-up of 4.3 years, 86 patients (7.9%) developed lung cancer. NO2 concentration was associated with lung cancer development in an unadjusted model (HR 1.219; p=0.042), while a marginal association was found in the primary model (HR 1.280; p=0.084). When NO2 concentration was stratified by the median value (21.0 ppb), exposure to high NO2 levels (≥21.0 ppb) was associated with a 2.0-fold increase in the risk of lung cancer development (HR 2.023; p=0.047) in the primary model.

CONCLUSION

Individual exposure to high NO2 levels may increase the risk of lung cancer development in patients with IPF.

Ambient Ultrafine Particulate Matter and Clinical Outcomes in Fibrotic Interstitial Lung Disease

Rationale: Particulate matter with an aerodynamic diameter ⩽2.5 μm is associated with adverse outcomes in fibrotic interstitial lung disease (fILD), but the impact of ultrafine particulates (UFPs; aerodynamic diameter ⩽100 nm) remains unknown. Objective: To evaluate UFP associations with clinical outcomes in fILD. Methods: We conducted a multicenter, prospective cohort study enrolling patients with fILD from the University of Pittsburgh Dorothy P. and Richard P. Simmons Center and the Pulmonary Fibrosis Foundation Patient Registry (PFF-PR). Using a national-scale UFP model, we linked exposures using three approaches in the Simmons cohort (residential address geocoordinates, ZIP code centroid geocoordinates, and ZIP code average) and two in the PFF-PR for which only five-digit ZIP code was available (ZIP code centroid and ZIP code average). We tested UFP associations with transplantation-free survival using multivariable Cox proportional-hazards models, baseline percentage predicted FVC and DlCO using multivariable linear regressions, and decline in FVC and DlCO using linear mixed models adjusting for age, sex, smoking, race, socioeconomic status, site, particulate matter with an aerodynamic diameter ⩽2.5, and nitrogen dioxide. Measurements and Main Results: Annual mean outdoor UFP concentrations for 2017 were estimated for 1,416 Simmons and 1,919 PFF-PR patients. Increased UFP concentration was associated with transplantation-free survival in fully adjusted Simmons residential address models (hazard ratio, 1.08 per 1,000 particles/cm3 [95% confidence interval, 1.01-1.15]; P = 0.02) but not PFF-PR models, which used less precise linkage approaches. Higher UFP exposure was associated with lower baseline FVC and more rapid FVC decline in the Simmons registry. Conclusions: Increased UFP exposure was associated with transplantation-free survival and lung function in the cohort with precise residential location linkage. This work highlights the need for more robust regulatory networks to study the health effects of UFPs nationwide.

Pazopanib attenuated bleomycin-induced pulmonary fibrosis via suppressing TGF-β1 signaling pathway

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial lung disease with a high mortality rate and limited treatment efficacy. Nintedanib, a tyrosine kinase inhibitor, is clinically used to treat pulmonary fibrosis. At present, only nintedanib is on the market for the treatment of pulmonary fibrosis. Pazopanib is a drug for the treatment of renal cell carcinoma and advanced soft tissue sarcoma.

Methods

In this study, we explored whether pazopanib can attenuate bleomycin (BLM)-induced pulmonary fibrosis and explored its antifibrotic mechanism. In vivo and in vitro investigations were carried out to investigate the efficacy and mechanism of action of pazopanib in pulmonary fibrosis.

Results

In vivo experiments showed that pazopanib can alleviate pulmonary fibrosis caused by BLM, reduce the degree of collagen deposition and improve lung function. In vitro experiments showed that pazopanib suppressed transforming growth factor-β1 (TGF-β1)-induced myofibroblast activation and promoted apoptosis and autophagy in myofibroblasts. Further mechanistic studies demonstrated that pazopanib inhibited the TGF-β1/Smad and non-Smad signaling pathways during fibroblast activation.

Conclusions

In conclusion, pazopanib attenuated BLM-induced pulmonary fibrosis by suppressing the TGF-β1 signaling pathway. Pazopanib inhibits myofibroblast activation, migration, autophagy, apoptosis, and extracellular matrix (ECM) buildup by downregulating the TGF-β1/Smad signal route and the TGF-β1/non-Smad signal pathway. It has the same target as nintedanib and is a tyrosine kinase inhibitor.

Interstitial lung disease: a review of classification, etiology, epidemiology, clinical diagnosis, pharmacological and non-pharmacological treatment

Interstitial lung diseases (ILDs) refer to a heterogeneous and complex group of conditions characterized by inflammation, fibrosis, or both, in the interstitium of the lungs. This results in impaired gas exchange, leading to a worsening of respiratory symptoms and a decline in lung function. While the etiology of some ILDs is unclear, most cases can be traced back to factors such as genetic predispositions, environmental exposures (including allergens, toxins, and air pollution), underlying autoimmune diseases, or the use of certain medications. There has been an increase in research and evidence aimed at identifying etiology, understanding epidemiology, improving clinical diagnosis, and developing both pharmacological and non-pharmacological treatments. This review provides a comprehensive overview of the current state of knowledge in the field of interstitial lung diseases.

Pulmonary vascular disease, environmental pollution, and climate change

Pollution and climate change constitute a combined, grave and pervasive threat to humans and to the life-support systems on which they depend. Evidence shows a strong association between pollution and climate change on cardiovascular and respiratory diseases, and pulmonary vascular disease (PVD) is no exception. An increasing number of studies has documented the impact of environmental pollution and extreme temperatures on pulmonary circulation and the right heart, on the severity and outcomes of patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (PH), on the incidence of pulmonary embolism, and the prevalence and severity of diseases associated with PH. Furthermore, the downstream consequences of climate change impair health care systems' accessibility, which could pose unique obstacles in the case of PVD patients, who require a complex and sophisticated network of health interventions. Patients, caretakers and health care professionals should thus be included in the design of policies aimed at adaptation to and mitigation of current challenges, and prevention of further climate change. The purpose of this review is to summarize the available evidence concerning the impact of environmental pollution and climate change on the pulmonary circulation, and to propose measures at the individual, healthcare and community levels directed at protecting patients with PVD.

PM10 increases mortality risk in rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

The effect of air pollution on the prognosis of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) remains poorly understood. We aimed to evaluate the effect of long-term exposure to particulate matter with an aerodynamic diameter of ≤10 µm (PM10) and nitrogen dioxide (NO2) on mortality in patients with RA-ILD.

METHODS

We included 309 patients (mean age, 61.7 years; male, 44.3%) with RA-ILD. Individual-level long-term exposures to PM10 and NO2 at their residential addresses were estimated using a national-scale exposure prediction model. The effect of the two air pollutants on mortality was estimated using a Cox-proportional hazards model adjusted for individual-level and area-level characteristics.

RESULTS

The median follow-up period was 4.8 years, and 40.8% of patients died or underwent lung transplantation. The annual average concentrations of PM10 and NO2 were 56.3 μg/m3 and 22.4 ppb, respectively. When air pollutant levels were stratified by quartiles, no association was observed between air pollutant concentration and mortality in patients with RA-ILD. However, when stratified by two groups (high exposure (top 25th percentile) vs low exposure (bottom 75th percentile)), we observed a significant association between high PM10 exposure and mortality (HR 1.68; 95% CI 1.11 to 2.52; p=0.013) but no association between NO2 exposure and mortality. In the subgroup analyses, the effect of high PM10 exposure on mortality was significant in patients aged <65 years (HR 1.98; 95% CI 1.02 to 3.85; p=0.045).

CONCLUSIONS

Our results indicated that high PM10 exposure may be associated with mortality in patients with RA-ILD.

Effects of indoor air pollution on clinical outcomes in patients with interstitial lung disease: protocol of a multicentre prospective observational study

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrosing interstitial lung disease with a poor prognosis. While there is evidence suggesting that outdoor air pollution affects the clinical course of IPF, the impact of indoor air pollution on patients with IPF has not been extensively studied. Therefore, this prospective multicentre observational study aims to investigate the association between indoor air pollution and clinical outcomes in patients with IPF.

METHODS AND ANALYSIS

This study enrolled 140 patients with IPF from 12 medical institutes in the Seoul and Metropolitan areas of the Republic of Korea. Over the course of 1 year, participants visited the institutes every 3 months, during which their clinical data and blood samples were collected. Additionally, indoor exposure to particulate matter ≤2.5 µm (PM2.5) was measured using MicroPEM (RTI International, Research Triangle Park, North Carolina, USA) in each participant's house for 5 days every 3 months. Lung function was assessed using both site spirometry at each institution and portable spirometry at each participant's house every 3 months. The study will analyse the impact of indoor PM2.5 on clinical outcomes, including mortality, acute exacerbation, changes in lung function and health-related quality of life, in the participants. This study represents the first attempt to evaluate the influence of indoor air pollution on the prognosis of patients with IPF.

ETHICS AND DISSEMINATION

This study has received approval from the institutional review board of all participating institutions, including Asan Medical Center, Seoul, Republic of Korea (2021-0072).

TRIAL REGISTRATION NUMBER

KCT0006217.

The impact of air pollution on interstitial lung disease: a systematic review and meta-analysis

Introduction

There is a growing body of evidence suggesting a causal relationship between interstitial lung disease (ILD) and air pollution, both for the development of the disease, and driving disease progression. We aim to provide a comprehensive literature review of the association between air pollution, and ILD, including idiopathic pulmonary fibrosis (IPF).

Methods

We systematically searched from six online database. Two independent authors (DL and CF) selected studies and critically appraised the risk of bias using the Newcastle-Ottawa Scale (NOS). Findings are presented through a narrative synthesis and meta-analysis. Meta-analyses were performed exclusively when there was a minimum of three studies examining identical pollutant-health outcome pairs, all evaluating equivalent increments in pollutant concentration, using a random effects model.

Results

24 observational studies conducted in 13 countries or regions were identified. Pollutants under investigation encompassed ozone (O3), nitrogen dioxide (NO2), Particulate matter with diameters of 10 micrometers or less (PM10) and 2.5 micrometers or less (PM2.5), sulfur dioxide (SO2), carbon monoxide (CO), nitric oxide (NO) and nitrogen oxides (NOx). We conducted meta-analyses to assess the estimated Risk Ratios (RRs) for acute exacerbations (AE)-IPF in relation to exposure to every 10 μg/m3 increment in air pollutant concentrations, including O3, NO2, PM10, and PM2.5. The meta-analysis revealed a significant association between the increased risk of AE-IPF in PM2.5, yielding RR 1.94 (95% CI 1.30-2.90; p = 0.001). Findings across all the included studies suggest that increased exposure to air pollutants may be linked to a range of health issues in individuals with ILDs.

Conclusion

A scarcity of available studies on the air pollutants and ILD relationship underscores the imperative for further comprehensive research in this domain. The available data suggest that reducing levels of PM2.5 in the atmosphere could potentially reduce AE frequency and severity in ILD patients.

Air pollution exposure and its effects on idiopathic pulmonary fibrosis: clinical worsening, lung function decline, and radiological deterioration

Introduction

Major urban pollutants have a considerable influence on the natural history of lung disease. However, this effect is not well known in idiopathic pulmonary fibrosis (IPF).

Aim

This study aimed to investigate the effects of air pollution on clinical worsening, lung function, and radiological deterioration in patients with IPF.

Methods

This exploratory retrospective cohort study included 69 patients with IPF, monitored from 2011 to 2020. Data on air pollution levels, including carbon monoxide (CO), nitrogen dioxide (NO2), particulate matter ≤ 2.5 μM (PM2.5), ozone (O3), and nitrogen oxides (NOx), were collected from the nearest air quality monitoring stations (<3.5 km from the patients' homes). Patient outcomes such as clinical worsening, lung function decline, and radiological deterioration were assessed over various exposure periods (1, 3, 6, 12, and 36 months). The statistical analyses were adjusted for various factors, including age, sex, smoking status, and treatment.

Results

There was an association between higher O3 levels and an increased likelihood of clinical worsening over 6 and 36 months of exposure (odds ratio [OR] and 95% confidence interval [CI] = 1.16 [1.01-1.33] and OR and 95% CI = 1.80 [1.07-3.01], respectively). Increased CO levels were linked to lung function decline over 12-month exposure periods (OR and 95% CI 1.63 = [1.01-2.63]). Lastly, radiological deterioration was significantly associated with higher CO, NO2, and NOx levels over 6-month exposure periods (OR and 95% CI = 2.14 [1.33-3.44], OR and 95% CI = 1.76 [1.15-2.66] and OR and 95% CI = 1.16 [1.03-1.3], respectively).

Conclusion

This study suggests that air pollution, specifically O3, CO, NO2, and NOx, could affect clinical worsening, lung function, and radiological outcomes in patients with IPF. These findings highlight the potential role of air pollution in the progression of IPF, emphasizing the need for further research and air quality control measures to mitigate its effects on respiratory health.

Current pharmacotherapies for advanced lung cancer with pre-existing interstitial lung disease : A literature review and future perspectives

Patients with interstitial lung disease (ILD), especially those with idiopathic pulmonary fibrosis, are at increased risk of developing lung cancer (LC). Pharmacotherapy for advanced LC has dramatically progressed in recent years;however, management of LC with pre-existing ILD (LC-ILD) is challenging due to serious concerns about the risk of acute exacerbation of ILD (AE-ILD). As patients with LC-ILD have been excluded from most prospective clinical trials of advanced LC, optimal pharmacotherapy remains to be elucidated. Although the antitumor activity of first-line platinum-based cytotoxic chemotherapy appears to be similar in advanced LC patients with or without ILD, its impact on the survival of patients with LC-ILD is limited. Immune checkpoint inhibitors may hold promise for long-term survival, but many challenges remain, including safety and appropriate patient selection. Further understanding the predictive factors for AE-ILD after receiving pharmacotherapy in LC-ILD may lead to appropriate patient selection and lower treatment risk. The aim of this review was to summarize the current evidence related to pharmacotherapy for advanced LC-ILD and discuss emerging areas of research. J. Med. Invest. 71 : 9-22, February, 2024.

Promotion of myofibroblast differentiation through repeated treatment of fibroblasts to low concentrations of PM2.5

Exposure to particulate matter ≤ 2.5 µm (PM2.5) is a risk factor for many lung diseases. Although the toxicologic effects of PM2.5 on airway epithelium are well-described, the effects of PM2.5 on fibroblasts in the lung are less studied. Here, we sought to examine the effects of PM2.5 on the differentiation of fibroblasts into myofibroblasts. Although a single treatment of fibroblasts did not result in a change in collagen or the myofibroblast marker α-SMA, exposing fibroblasts to sequential treatments with PM2.5 at low concentrations caused a robust increase in these proteins. Treatment of fibroblasts with IMD0354, an inhibitor to nuclear factor κB, but not with an antagonist to aryl hydrocarbon receptor, abolished the ability of PM2.5 to induce myofibroblast differentiation. These data demonstrate that potential impact of PM2.5 to fibroblast activation and fibrosis and support the importance of utilizing low concentrations and varying exposure protocols to toxicologic studies.

Clinical impact of pre-existing acute exacerbation in patients with interstitial lung disease who underwent lung transplantation

BACKGROUND

Acute exacerbation of interstitial lung disease (AE-ILD) significantly impacts prognosis, leading to high mortality rates. Although lung transplantation is a life-saving treatment for selected patients with ILD, its outcomes in those presenting with AE-ILD have yielded conflicting results compared with those with stable ILD. This study aims to investigate the impact of pre-existing AE on the prognosis of ILD patients who underwent lung transplantation.

METHOD

We conducted a single-center retrospective study by reviewing the medical records of 108 patients who underwent lung transplantation for predisposing ILD at Asan Medical Center, Seoul, South Korea, between 2008 and 2022. The primary objective was to compare the survival of patients with AE-ILD at the time of transplantation with those without AE-ILD.

RESULTS

Among the 108 patients, 52 (48.1%) experienced AE-ILD at the time of lung transplantation, and 81 (75.0%) required pre-transplant mechanical ventilation. Although the type of ILD (IPF vs. non-IPF ILD) did not affect clinical outcomes after transplantation, AE-ILD was associated with worse survival outcomes. The survival probabilities at 90 days, 1 year, and 3 years post-transplant for patients with AE-ILD were 86.5%, 73.1%, and 60.1%, respectively, while those for patients without AE-ILD were higher, at 92.9%, 83.9%, and 79.6% (p = 0.032). In the multivariable analysis, pre-existing AE was an independent prognostic factor for mortality in ILD patients who underwent lung transplantation.

CONCLUSIONS

Although lung transplantation remains an effective treatment option for ILD patients with pre-existing AE, careful consideration is needed, especially in patients requiring pre-transplant mechanical respiratory support.

Myeloid Heterogeneity Mediates Acute Exacerbations of Pulmonary Fibrosis

Epidemiological evidence indicates that exposure to particulate matter is linked to the development of idiopathic pulmonary fibrosis (IPF) and increases the incidence of acute exacerbations of IPF. In addition to accelerating the rate of lung function decline, exposure to fine particulate matter (particulate matter smaller than 2.5 μm [PM2.5]) is a risk factor for increased mortality in subjects with IPF. In this article, we show that exposure to PM2.5 mediates monocyte recruitment and fibrotic progression in mice with established fibrosis. In mice with established fibrosis, bronchoalveolar lavage cells showed monocyte/macrophage heterogeneity after exposure to PM2.5. These cells had a significant inflammatory and anti-inflammatory signature. The mixed heterogeneity of cells contributed to the proinflammatory and anti-inflammatory response. Although monocyte-derived macrophages were recruited to the lung in bleomycin-injured mice treated with PM2.5, recruitment of monocytes expressing Ly6Chi to the lung promoted progression of fibrosis, reduced lung aeration on computed tomography, and impacted lung compliance. Ly6Chi monocytes isolated from PM2.5-exposed fibrotic mice showed enhanced expression of proinflammatory markers compared with fibrotic mice exposed to vehicle. Moreover, IPF bronchoalveolar lavage cells treated ex vivo with PM2.5 showed an exaggerated inflammatory response. Targeting Ly6Chi monocyte recruitment inhibited fibrotic progression in mice. Moreover, the adoptive transfer of Ly6Chi monocytes exacerbated established fibrosis. These observations suggest that enhanced recruitment of Ly6Chi monocytes with a proinflammatory phenotype mediates acute exacerbations of pulmonary fibrosis, and targeting these cells may provide a potential novel therapeutic target to protect against acute exacerbations of IPF.

Animal models of acute exacerbation of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive scarring interstitial lung disease with an unknown cause. Some patients may experience acute exacerbations (AE), which result in severe lung damage visible on imaging or through examination of tissue samples, often leading to high mortality rates. However, the etiology and pathogenesis of AE-IPF remain unclear. AE-IPF patients exhibit diffuse lung damage, apoptosis of type II alveolar epithelial cells, and an excessive inflammatory response. Establishing a reliable animal model of AE is critical for investigating the pathogenesis. Recent studies have reported a variety of animal models for AE-IPF, each with its own advantages and disadvantages. These models are usually established in mice with bleomycin-induced pulmonary fibrosis, using viruses, bacteria, small peptides, or specific drugs. In this review, we present an overview of different AE models, hoping to provide a useful resource for exploring the mechanisms and targeted therapies for AE-IPF.

Environmental Causes of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), the most common and severe of the idiopathic interstitial pneumonias, is a chronic and relentlessly progressive disease, which occurs mostly in middle-aged and elderly males. Although IPF is by definition "idiopathic", multiple factors have been reported to increase disease risk, aging being the most prominent one. Several occupational and environmental exposures, including metal dust, wood dust and air pollution, as well as various lifestyle variables, including smoking and diet, have also been associated with an increased risk of IPF, probably through interaction with genetic factors. Many of the predisposing factors appear to act also as trigger for acute exacerbations of the disease, which herald a poor prognosis. The more recent literature on inhalation injuries has focused on the first responders in the World Trade Center attacks and military exposure. In this review, we present an overview of the environmental and occupational causes of IPF and its pathogenesis. While our list is not comprehensive, we have selected specific exposures to highlight based on their overall disease burden.

Walking the path of treatable traits in interstitial lung diseases

Interstitial lung diseases (ILDs) are complex and heterogeneous diseases. The use of traditional diagnostic classification in ILD can lead to suboptimal management, which is worsened by not considering the molecular pathways, biological complexity, and disease phenotypes. The identification of specific "treatable traits" in ILDs, which are clinically relevant and modifiable disease characteristics, may improve patient's outcomes. Treatable traits in ILDs may be classified into four different domains (pulmonary, aetiological, comorbidities, and lifestyle), which will facilitate identification of related assessment tools, treatment options, and expected benefits. A multidisciplinary care team model is a potential way to implement a "treatable traits" strategy into clinical practice with the aim of improving patients' outcomes. Multidisciplinary models of care, international registries, and the use of artificial intelligence may facilitate the implementation of the "treatable traits" approach into clinical practice. Prospective studies are needed to test potential therapies for a variety of treatable traits to further advance care of patients with ILD.

Impact of outdoor air pollution on severity and mortality in COVID-19 pneumonia

The relationship between exposure to air pollution and the severity of coronavirus disease 2019 (COVID-19) pneumonia and other outcomes is poorly understood. Beyond age and comorbidity, risk factors for adverse outcomes including death have been poorly studied. The main objective of our study was to examine the relationship between exposure to outdoor air pollution and the risk of death in patients with COVID-19 pneumonia using individual-level data. The secondary objective was to investigate the impact of air pollutants on gas exchange and systemic inflammation in this disease. This cohort study included 1548 patients hospitalised for COVID-19 pneumonia between February and May 2020 in one of four hospitals. Local agencies supplied daily data on environmental air pollutants (PM10, PM2.5, O3, NO2, NO and NOX) and meteorological conditions (temperature and humidity) in the year before hospital admission (from January 2019 to December 2019). Daily exposure to pollution and meteorological conditions by individual postcode of residence was estimated using geospatial Bayesian generalised additive models. The influence of air pollution on pneumonia severity was studied using generalised additive models which included: age, sex, Charlson comorbidity index, hospital, average income, air temperature and humidity, and exposure to each pollutant. Additionally, generalised additive models were generated for exploring the effect of air pollution on C-reactive protein (CRP) level and SpO2/FiO2 at admission. According to our results, both risk of COVID-19 death and CRP level increased significantly with median exposure to PM10, NO2, NO and NOX, while higher exposure to NO2, NO and NOX was associated with lower SpO2/FiO2 ratios. In conclusion, after controlling for socioeconomic, demographic and health-related variables, we found evidence of a significant positive relationship between air pollution and mortality in patients hospitalised for COVID-19 pneumonia. Additionally, inflammation (CRP) and gas exchange (SpO2/FiO2) in these patients were significantly related to exposure to air pollution.

Where you live matters: Roadways, air pollution and lung function in patients with idiopathic pulmonary fibrosis

See related article

Long-term exposure to low concentrations of air pollution and decline in lung function in people with idiopathic pulmonary fibrosis: Evidence from Australia

BACKGROUND AND OBJECTIVE

Little is known about the association between ambient air pollution and idiopathic pulmonary fibrosis (IPF) in areas with lower levels of exposure. We aimed to investigate the impact of air pollution on lung function and rapid progression of IPF in Australia.

METHODS

Participants were recruited from the Australian IPF Registry (n = 570). The impact of air pollution on changes in lung function was assessed using linear mixed models and Cox regression was used to investigate the association with rapid progression.

RESULTS

Median (25th-75th percentiles) annual fine particulate matter (<2.5 μm, PM2.5 ) and nitrogen dioxide (NO2 ) were 6.8 (5.7, 7.9) μg/m3 and 6.7 (4.9, 8.2) ppb, respectively. Compared to living more than 100 m from a major road, living within 100 m was associated with a 1.3% predicted/year (95% confidence interval [CI] -2.4 to -0.3) faster annual decline in diffusing capacity of the lungs for carbon monoxide (DLco). Each interquartile range (IQR) of 2.2 μg/m3 increase in PM2.5 was associated with a 0.9% predicted/year (95% CI -1.6 to -0.3) faster annual decline in DLco, while there was no association observed with NO2 . There was also no association between air pollution and rapid progression of IPF.

CONCLUSION

Living near a major road and increased PM2.5 were both associated with an increased rate of annual decline in DLco. This study adds to the evidence supporting the negative effects of air pollution on lung function decline in people with IPF living at low-level concentrations of exposure.

Re-hospitalisation predicts poor prognosis after acute exacerbation of interstitial lung disease

BACKGROUND

Several markers have been identified to increase the risk for acute exacerbation of interstitial lung disease (AE-ILD) or mortality related to AE-ILD. However, less is known about the risk predictors of ILD patients who have survived AE. The aim of the study was to characterise AE-ILD survivors and investigate prognostic factors in this subpopulation.

METHODS

All AE-ILD patients (n = 95) who had been discharged alive from two hospitals located in Northern Finland were selected from a population of 128 AE-ILD patients. Clinical data related to the hospital treatment and six-month follow-up visit were collected retrospectively from medical records.

RESULTS

Fifty-three patients with idiopathic pulmonary fibrosis (IPF) and 42 patients with other ILD were identified. Two thirds of the patients had been treated without invasive or non-invasive ventilation support. The clinical features of six-month survivors (n = 65) and non-survivors (n = 30) did not differ in terms of medical treatment or oxygen requirements. Of the patients, 82.5% used corticosteroids at the six-month follow-up visit. Fifty-two patients experienced at least one non-elective respiratory re-hospitalisation before the six-month follow-up visit. In a univariate model, IPF diagnosis, high age and a non-elective respiratory re-hospitalisation increased the risk of death, although re-hospitalisation was the only independent risk factor in a multivariate model. In six-month survivors, there was no statistically significant decrease in pulmonary function test results (PFT) examined at the follow-up visit compared with earlier PFT examined near the time of AE-ILD.

CONCLUSIONS

The AE-ILD survivors were a heterogeneous group of patients both clinically and in terms of their outcome. A non-elective respiratory re-hospitalisation was identified as a marker of poor prognosis among AE-ILD survivors.

Role of the internet of medical things in care for patients with interstitial lung disease

PURPOSE OF REVIEW

Online technologies play an increasing role in facilitating care for patients with interstitial lung disease (ILD). In this review, we will give an overview of different applications of the internet of medical things (IoMT) for patients with ILD.

RECENT FINDINGS

Various applications of the IoMT, including teleconsultations, virtual MDTs, digital information, and online peer support, are now used in daily care of patients with ILD. Several studies showed that other IoMT applications, such as online home monitoring and telerehabilitation, seem feasible and reliable, but widespread implementation in clinical practice is lacking. The use of artificial intelligence algorithms and online data clouds in ILD is still in its infancy, but has the potential to improve remote, outpatient clinic, and in-hospital care processes. Further studies in large real-world cohorts to confirm and clinically validate results from previous studies are needed.

SUMMARY

We believe that in the near future innovative technologies, facilitated by the IoMT, will further enhance individually targeted treatment for patients with ILD by interlinking and combining data from various sources.

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.

Acute exacerbation of interstitial lung disease in the intensive care unit: Principles of diagnostic evaluation and management

Interstitial lung disease (ILD) is typically managed on an outpatient basis. Critical care physicians manage patients with ILD in the setting of an acute exacerbation (ILD flare) causing severe hypoxia. The principles of management of acute exacerbation of ILD are different from those used to manage patients with acute respiratory distress syndrome from sepsis, etc. Selected patients may be candidates for aggressive measures like extracorporeal membrane oxygenation and lung transplantation, while almost all patients will benefit from early palliative care. This review focused on the types of ILD, diagnosis, and management pathways for this challenging condition.

The association between air pollution and the severity at diagnosis and progression of systemic sclerosis-associated interstitial lung disease: results from the retrospective ScleroPol study

OBJECTIVE

To investigate the association of air pollution exposure with the severity of interstitial lung disease (ILD) at diagnosis and ILD progression among patients with systemic sclerosis (SSc)-associated ILD.

METHODS

We conducted a retrospective two-center study of patients with SSc-associated ILD diagnosed between 2006 and 2019. Exposure to the air pollutants particulate matter of up to 10 and 2.5 µm in diameter (PM₁₀, PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃) was assessed at the geolocalization coordinates of the patients' residential address. Logistic regression models were used to evaluate the association between air pollution and severity at diagnosis according to the Goh staging algorithm, and progression at 12 and 24 months.

RESULTS

We included 181 patients, 80% of whom were women; 44% had diffuse cutaneous scleroderma, and 56% had anti-topoisomerase I antibodies. ILD was extensive, according to the Goh staging algorithm, in 29% of patients. O₃ exposure was associated with the presence of extensive ILD at diagnosis (adjusted OR: 1.12, 95% CI 1.05-1.21; p value = 0.002). At 12 and 24 months, progression was noted in 27/105 (26%) and 48/113 (43%) patients, respectively. O₃ exposure was associated with progression at 24 months (adjusted OR: 1.10, 95% CI 1.02-1.19; p value = 0.02). We found no association between exposure to other air pollutants and severity at diagnosis and progression.

CONCLUSION

Our findings suggest that high levels of O₃ exposure are associated with more severe SSc-associated ILD at diagnosis, and progression at 24 months.

PM2.5 promotes pulmonary fibrosis by mitochondrial dysfunction

Pulmonary fibrosis is known as an incurable lung disorder with irreversible progression of chronic injury, myofibroblast proliferation, extracellular matrix (ECM) accumulation, and tissue scarring. Atmospheric particulate matter 2.5 (PM_2.5 ) is implicated as a risk factor of several diseases, especially lung diseases such as pulmonary fibrosis. The molecular mechanism which participates PM_2.5 -induced pulmonary fibrosis in type II alveolar cells (AEII) has yet to be determined. Our results proved that short- and long-term exposure to PM_2.5 significantly stimulated epithelial-mesenchymal transition (EMT) activity in AEII cells, according to, changes in gene signature analyzed by RNA-seq and cell morphology. Furthermore, Gene Ontology (GO) enrichment analysis also suggested that mitochondrial dysfunction was related to progression of pulmonary fibrosis in AEII after PM_2.5 exposure. We observed a marked decline in mitochondria membrane potential (MMP), as well as fragmented mitochondria, in AEII cells exposed to PM_2.5 , which suggests that energy metabolism is suppressed after PM_2.5 exposure. We also confirmed that PM_2.5 exposure could influence the expression levels of Mfn1, Mfn2, and Drp1 in AEII. Pretreatment of mitochondrial fusion promoter M1 was able to reverse mitochondrial dysfunction as well as EMT in AEII. These data suggested the key role of mitochondrial fragmentation in AEII, which was induced by PM_2.5 exposure, and participated pathogenesis of pulmonary fibrosis. Finally, we investigated the response of lung tissue exposed to PM_2.5 in vivo. The data indicated that the lung tissue exposed to PM_2.5 obviously induced collagen accumulation. Moreover, IHC results revealed that PM_2.5 enhanced Drp1 expression but suppressed Mfn1 and Mfn2 expression in lung tissue. The current study provides novel insight of pulmonary fibrosis caused by PM_2.5 exposure.

A Systematic Review and Meta-analysis of Clinical, Respiratory, and Biochemical Risk Factors for Acute Exacerbation of idiopathic Pulmonary Fibrosis

BACKGROUND

A better capacity to identify patients with idiopathic pulmonary fibrosis (IPF) at risk of acute exacerbation (AEIPF) might improve outcomes and reduce healthcare costs.

AIMS

We critically appraised the available evidence of the differences in clinical, respiratory, and biochemical parameters between AEIPF and IPF patients with stable disease (SIPF) by conducting a systematic review and meta-analysis.

METHODS

PubMed, Web of Science and Scopus were reviewed up until August 1, 2022, for studies reporting differences in clinical, respiratory, and biochemical parameters (including investigational biomarkers) between AEIPF and SIPF patients. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias.

RESULTS

Twenty-nine cross-sectional studies published between 2010 and 2022 were identified (all with a low risk of bias). Of the 32 meta-analysed parameters, significant differences were observed between groups, assessed through standard mean differences or relative ratios, with age, forced vital capacity, vital capacity, carbon monoxide diffusion capacity, total lung capacity, oxygen partial pressure, alveolar-arterial oxygen gradient, P/F ratio, 6 min walk test distance, C-reactive protein, lactate dehydrogenase, white blood cell count, albumin, Krebs von den Lungen 6, surfactant protein D, high mobility group box 1 protein, and interleukin-1β, 6, and 8.

CONCLUSIONS

We identified significant differences between AEIPF and SIPF patients in age and specific parameters of respiratory function, inflammation, and epithelial lung damage. Prospective studies are warranted to determine the capacity of these parameters to predict AEIPF more accurately (PROSPERO registration number: CRD42022356640).

MitoQ ameliorates PM2.5-induced pulmonary fibrosis through regulating the mitochondria DNA homeostasis

Pulmonary fibrosis is a severe pulmonary disease, and may related to PM_2.5 exposure. Our study aims to explore the pathogenesis of PM_2.5-induced pulmonary fibrosis, and MitoQ protective effect in this process. Our results find that inflammatory cells aggregation and pulmonary fibrosis in mice lung after PM_2.5 exposure. Moreover, Collagen I/III overproduction, EMT and TGF-β1/Smad2 pathway activation in mice lung and BEAS-2B after PM_2.5 exposure. Fortunately, these changes were partially ameliorated after MitoQ treatment. Meanwhile, severe oxidative stress, mitochondrial homeostasis imbalance, overproduction of 8-oxoG (7,8-dihydro-8-oxoguanine), as well as the inhibition of SIRT3/OGG1 pathway have founded in mice lung or BEAS-2B after PM_2.5 exposure, which were alleviated by MitoQ treatment. Collectively, our study found that oxidative stress, especially mitochondrial oxidative stress participates in the PM_2.5-induced pulmonary fibrosis, and MitoQ intervention had a protective effect on this progress. Moreover, mitochondrial DNA homeostasis might participate in the pulmonary fibrosis caused by PM_2.5 exposure. Our study provides a novel pathogenesis of PM_2.5-caused pulmonary fibrosis and a possible targeted therapy for the pulmonary diseases triggered by PM_2.5.

Pathogenesis, clinical features, and phenotypes of pulmonary hypertension associated with interstitial lung disease: A consensus statement from the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative - Group 3 Pulmonary Hypertension

Pulmonary hypertension (PH) is a frequent complication of interstitial lung disease (ILD). Although PH has mostly been described in idiopathic pulmonary fibrosis, it can manifest in association with many other forms of ILD. Associated pathogenetic mechanisms are complex and incompletely understood but there is evidence of disruption of molecular and genetic pathways, with panvascular histopathologic changes, multiple pathophysiologic sequelae, and profound clinical ramifications. While there are some recognized clinical phenotypes such as combined pulmonary fibrosis and emphysema and some possible phenotypes such as connective tissue disease associated with ILD and PH, the identification of further phenotypes of PH in ILD has thus far proven elusive. This statement reviews the current evidence on the pathogenesis, recognized patterns, and useful diagnostic tools to detect phenotypes of PH in ILD. Distinct phenotypes warrant recognition if they are characterized through either a distinct presentation, clinical course, or treatment response. Furthermore, we propose a set of recommendations for future studies that might enable the recognition of new phenotypes.

Relationship between air pollution exposure and the progression of idiopathic pulmonary fibrosis in Madrid: Chronic respiratory failure, hospitalizations, and mortality. A retrospective study

Introduction

Air pollution has a significant impact on the morbidity and mortality of various respiratory diseases. However, this has not been widely studied in diffuse interstitial lung diseases, specifically in idiopathic pulmonary fibrosis.

Objective

In this study we aimed to assess the relationship between four major air pollutants individually [carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and nitrogen oxides (NOx)] and the development of chronic respiratory failure, hospitalization due to respiratory causes and mortality in patients with idiopathic pulmonary fibrosis.

Methods

We conducted an exploratory retrospective panel study from 2011 to 2020 in 69 patients with idiopathic pulmonary fibrosis from the pulmonary medicine department of a tertiary hospital. Based on their geocoded residential address, levels of each pollutant were estimated 1, 3, 6, 12, and 36 months prior to each event (chronic respiratory failure, hospital admission and mortality). Data was collected from the air quality monitoring stations of the Community of Madrid located &lt;3.5 km (2.2 miles) from each patient's home.

Results

The increase in average values of CO [OR 1.62 (1.11–2.36) and OR 1.84 (1.1–3.06)], NO2 [OR 1.64 (1.01–2.66)], and NOx [OR 1.11 (1–1.23) and OR 1.19 (1.03–1.38)] were significantly associated with the probability of developing chronic respiratory failure in different periods. In addition, the averages of NO2, O3, and NOx were significantly associated with the probability of hospital admissions due to respiratory causes and mortality in these patients.

Conclusion

Air pollution is associated with an increase in the probability of developing chronic respiratory failure, hospitalization due to respiratory causes and mortality in patients with idiopathic pulmonary fibrosis.

Nitrogen dioxide increases the risk of disease progression in idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVE

Air pollution affects clinical course and prognosis of idiopathic pulmonary fibrosis (IPF). However, the effect of individual exposure to air pollutants on disease progression is unclear. We aimed to identify the effect of individual exposure to nitrogen dioxide (NO₂ ) and particulate matter (aerodynamic diameter ≤ 10 μm [PM₁₀ ]) on disease progression in patients with IPF.

METHODS

The serial lung function data of 946 IPF patients (mean age: 65.4 years, male: 80.9%) were analysed. Individual-level long-term exposures to NO₂ and PM₁₀ at the residential addresses of patients were estimated using a national-scale exposure prediction model, constructed based on air quality regulatory monitoring data. Progression was defined as a relative decline (≥10%) in forced vital capacity. Individual- and area-level covariates were adjusted in the primary analysis model.

RESULTS

Overall, 547 patients (57.8%) experienced progression during a median follow-up of 1.0 year (interquartile range: 0.4-2.6 years). In the primary model, a 10-ppb increase in NO₂ concentration was associated with a 10.5% increase in the risk of progression (hazard ratio [HR] = 1.105; 95% CI = 1.000-1.219) in patients with IPF. There was also an increasing trend of progression in patients with IPF according to the second to fourth quartiles of NO₂ (Q2 [HR = 1.299; 95% CI = 0.972-1.735], Q3 [1.409; 1.001-1.984], Q4 [1.598; 1.106-2.310]) compared to the first quartile. We found no association between PM₁₀ and progression in IPF patients.

CONCLUSION

Our data suggest that increased individual exposure to NO₂ can increase the risk of progression in patients with IPF.

PM2.5 and constituent component impacts on global DNA methylation in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease (ILD) whose outcomes are worsened with air pollution exposures. DNA methylation (DNAm) patterns are altered in lungs and blood from patients with IPF, but the relationship between air pollution exposures and DNAm patterns in IPF remains unexplored. This study aimed to evaluate the association of PM_2.5 and constituent components with global DNAm in patients with IPF. Patients enrolled in either the University of Pittsburgh Simmons Center for ILD Registry (Simmons) or the U.S.-wide Pulmonary Fibrosis Foundation (PFF) Patient Registry with peripheral blood DNA samples were included. The averages of monthly exposures to PM_2.5 and constituents over 1-year and 3-months pre-blood collection were matched to patient residential coordinates using satellite-derived hybrid models. Global DNAm percentage (%5 mC) was determined using the ELISA-based MethylFlash assay. Associations of pollutants with %5 mC were assessed using beta-regression, Cox models for mortality, and linear regression for baseline lung function. Mediation proportion was determined for models where pollutant-mortality and pollutant-%5 mC associations were significant. Inclusion criteria were met by 313 Simmons and 746 PFF patients with IPF. Higher PM_2.5 3-month exposures prior to blood collection were associated with higher %5 mC in Simmons (β = 0.02, 95%CI 0.0003-0.05, p = 0.047), with trends in the same direction in the 1-year period in both cohorts. Higher exposures to sulfate, nitrate, ammonium, and black carbon constituents were associated with higher %5 mC in multiple models. Percent 5 mC was not associated with IPF mortality or lung function, but was found to mediate between 2 and 5% of the associations of PM_2.5, sulfate, and ammonium with mortality. In conclusion, we found that higher global DNAm is a novel biomarker for increased PM_2.5 and anthropogenic constituent exposure in patients with IPF. Mechanistic research is needed to determine if DNAm has pathogenic relevance in mediating associations between pollutants and mortality in IPF.

Air pollutants, genetic susceptibility and risk of incident idiopathic pulmonary fibrosis

BACKGROUND

Air pollutants are considered as non-negligible risk factors of idiopathic pulmonary fibrosis (IPF). However, the relationship between long-term air pollution and the incidence of IPF is unknown. Our objective was to explore the associations of air pollutants with IPF risk and further assess the modification effect of genetic susceptibility.

METHODS

We used land-use regression model estimated concentrations of nitrogen dioxide (NO₂), nitrogen oxides (NO _x ) and particulate matter (fine particulate matter with diameter <2.5 μm (PM_2.5) and particulate matter with diameter <10 μm (PM₁₀)). The polygenic risk score (PRS) was constructed using 13 independent single nucleotide polymorphisms. Cox proportional hazard models were used to evaluate the associations of air pollutants with IPF risk and further investigate the modification effect of genetic susceptibility. Additionally, absolute risk was calculated.

RESULTS

Among 433 738 participants from the UK Biobank, the incidence of IPF was 27.45 per 100 000 person-years during a median follow-up of 11.78 years. The adjusted hazard ratios of IPF for each interquartile range increase in NO₂, NO _x and PM_2.5 were 1.11 (95% CI 1.03-1.19), 1.07 (95% CI 1.01-1.13) and 1.09 (95% CI 1.02-1.17), respectively. PM_2.5 had the highest population attribution risk, followed by NO _x and NO₂. There were additive interactions between NO₂, NO _x and PM_2.5 and genetic susceptibility. Participants with a high PRS and high air pollution had the highest risk of incident IPF compared with those with a low PRS and low air pollution (adjusted hazard ratio: NO₂ 3.94 (95% CI 2.77-5.60), NO _x 3.08 (95% CI 2.21-4.27), PM_2.5 3.65 (95% CI 2.60-5.13) and PM₁₀ 3.23 (95% CI 2.32-4.50)).

CONCLUSION

Long-term exposures to air pollutants may elevate the risk of incident IPF. There are additive effects of air pollutants and genetic susceptibility on IPF risk.

Prognosis and Survival in Idiopathic Pulmonary Fibrosis in the Era of Antifibrotic Therapy in Italy: Evidence from a Longitudinal Population Study Based on Healthcare Utilization Databases

The aim was to evaluate the determinants of acute exacerbation (AE) and death in new cases of idiopathic pulmonary fibrosis (IPF) using administrative databases in the Marche Region. Adults at their first prescription of antifibrotics or hospitalization with a diagnosis of IPF occurring in 2014-2019 were considered as new cases. Multiple Cox regression was used to estimate the risk of AE and of all-cause mortality adjusted by demographic and clinical characteristics, stratifying patients according to antifibrotic treatment. Overall, 676 new cases of IPF were identified and 276 deaths and 248 AE events occurred. In never-treated patients, the risk of AE was higher in patients with poor health conditions at diagnosis; the risk of death was higher in males, in patients aged ≥75 and in those with poor health conditions at baseline. The increasing number of AEs increased the risk of death in treated and never-treated patients. Within the limits of an observational study based on secondary data, the combined use of healthcare administrative databases allows the accurate analysis of progression and survival of IPF from the beginning of the antifibrotic therapy era, suggesting that timely and early diagnosis is critical to prescribing the most suitable treatment to increase survival and maintain a healthy life expectancy.