Association Between Interstitial Lung Abnormalities and All-Cause Mortality

Impact of Interstitial Lung Abnormalities on Disease Expression and Outcomes in COPD or Emphysema: A Systematic Review

Background

Both COPD and interstitial lung abnormalities (ILAs) are conditions associated with smoking and age. The impact of coexistent ILAs on the manifestations and outcomes of COPD or emphysema awaits evaluation.

Methods

We searched PubMed and Embase using Medical Subject Headings terms in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

Eleven studies were included in the review. The sample size of the studies ranged from 30 to 9579. ILAs were reported in 6.5% to 25.7% of the patients with COPD/emphysema, higher than that reported in the general populations. COPD/emphysema patients with ILAs were older, mostly male, and had a higher smoking index than those without ILAs. Hospital admission and mortality were increased in COPD patients with ILAs compared to those without ILAs, whereas the frequency of COPD exacerbations was discrepant in 2 of the studies. The FEV₁ and FEV₁% predicted tended to be higher in the group with ILAs, but not significantly in most of the studies.

Conclusion

ILAs were more frequent in subjects with COPD/emphysema than in the general population. ILAs may have a negative impact on hospital admission and mortality of COPD/emphysema. The impact of ILAs on lung functions and exacerbations of COPD/emphysema was discrepant in these studies. Further prospective studies are warranted to provide high-quality evidence of the association and interaction between COPD/emphysema and ILAs.

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.

Machine learning in radiology: the new frontier in interstitial lung diseases

Challenges for the effective management of interstitial lung diseases (ILDs) include difficulties with the early detection of disease, accurate prognostication with baseline data, and accurate and precise response to therapy. The purpose of this Review is to describe the clinical and research gaps in the diagnosis and prognosis of ILD, and how machine learning can be applied to image biomarker research to close these gaps. Machine-learning algorithms can identify ILD in at-risk populations, predict the extent of lung fibrosis, correlate radiological abnormalities with lung function decline, and be used as endpoints in treatment trials, exemplifying how this technology can be used in care for people with ILD. Advances in image processing and analysis provide further opportunities to use machine learning that incorporates deep-learning-based image analysis and radiomics. Collaboration and consistency are required to develop optimal algorithms, and candidate radiological biomarkers should be validated against appropriate predictors of disease outcomes.

Quantitative Interstitial Abnormality Progression and Outcomes in the Genetic Epidemiology of COPD and Pittsburgh Lung Screening Study Cohorts

BACKGROUND

The risk factors and clinical outcomes of quantitative interstitial abnormality progression over time have not been characterized.

RESEARCH QUESTIONS

What are the associations of quantitative interstitial abnormality progression with lung function, exercise capacity, and mortality? What are the demographic and genetic risk factors for quantitative interstitial abnormality progression?

STUDY DESIGN AND METHODS

Quantitative interstitial abnormality progression between visits 1 and 2 was assessed from 4,635 participants in the Genetic Epidemiology of COPD (COPDGene) cohort and 1,307 participants in the Pittsburgh Lung Screening Study (PLuSS) cohort. We used multivariable linear regression to determine the risk factors for progression and the longitudinal associations between progression and FVC and 6-min walk distance, and Cox regression models for the association with mortality.

RESULTS

Age at enrollment, female sex, current smoking status, and the MUC5B minor allele were associated with quantitative interstitial abnormality progression. Each percent annual increase in quantitative interstitial abnormalities was associated with annual declines in FVC (COPDGene: 8.5 mL/y; 95% CI, 4.7-12.4 mL/y; P < .001; PLuSS: 9.5 mL/y; 95% CI, 3.7-15.4 mL/y; P = .001) and 6-min walk distance, and increased mortality (COPDGene: hazard ratio, 1.69; 95% CI, 1.34-2.12; P < .001; PLuSS: hazard ratio, 1.28; 95% CI, 1.10-1.49; P = .001).

INTERPRETATION

The objective, longitudinal measurement of quantitative interstitial abnormalities may help identify people at greatest risk for adverse events and most likely to benefit from early intervention.

Interstitial lung abnormalities in a large clinical lung cancer screening cohort: association with mortality and ILD diagnosis

BACKGROUND

Interstitial lung abnormalities (ILA) are CT findings suggestive of interstitial lung disease in individuals without a prior diagnosis or suspicion of ILD. Previous studies have demonstrated that ILA are associated with clinically significant outcomes including mortality. The aim of this study was to determine the prevalence of ILA in a large CT lung cancer screening program and the association with clinically significant outcomes including mortality, hospitalizations, cancer and ILD diagnosis.

METHODS

This was a retrospective study of individuals enrolled in a CT lung cancer screening program from 2012 to 2014. Baseline and longitudinal CT scans were scored for ILA per Fleischner Society guidelines. The primary analyses examined the association between baseline ILA and mortality, all-cause hospitalization, and incidence of lung cancer. Kaplan-Meier plots were generated to visualize the associations between ILA and lung cancer and all-cause mortality. Cox regression proportional hazards models were used to test for this association in both univariate and multivariable models.

RESULTS

1699 subjects met inclusion criteria. 41 (2.4%) had ILA and 101 (5.9%) had indeterminate ILA on baseline CTs. ILD was diagnosed in 10 (24.4%) of 41 with ILA on baseline CT with a mean time from baseline CT to diagnosis of 4.47 ± 2.72 years. On multivariable modeling, the presence of ILA remained a significant predictor of death, HR 3.87 (2.07, 7.21; p < 0.001) when adjusted for age, sex, BMI, pack years and active smoking, but not of lung cancer and all-cause hospital admission. Approximately 50% with baseline ILA had progression on the longitudinal scan.

CONCLUSIONS

ILA identified on baseline lung cancer screening exams are associated with all-cause mortality. In addition, a significant proportion of patients with ILA are subsequently diagnosed with ILD and have CT progression on longitudinal scans.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov; No.: NCT04503044.

TRIB3 promotes pulmonary fibrosis through inhibiting SLUG degradation by physically interacting with MDM2

Pulmonary fibrosis (PF) is the pathological structure of incurable fibroproliferative lung diseases that are attributed to the repeated lung injury-caused failure of lung alveolar regeneration (LAR). Here, we report that repetitive lung damage results in a progressive accumulation of the transcriptional repressor SLUG in alveolar epithelial type II cells (AEC2s). The abnormal increased SLUG inhibits AEC2s from self-renewal and differentiation into alveolar epithelial type I cells (AEC1s). We found that the elevated SLUG represses the expression of the phosphate transporter SLC34A2 in AEC2s, which reduces intracellular phosphate and represses the phosphorylation of JNK and P38 MAPK, two critical kinases supporting LAR, leading to LAR failure. TRIB3, a stress sensor, interacts with the E3 ligase MDM2 to suppress SLUG degradation in AEC2s by impeding MDM2-catalyzed SLUG ubiquitination. Targeting SLUG degradation by disturbing the TRIB3/MDM2 interaction using a new synthetic staple peptide restores LAR capacity and exhibits potent therapeutic efficacy against experimental PF. Our study reveals a mechanism of the TRIB3-MDM2-SLUG-SLC34A2 axis causing the LAR failure in PF, which confers a potential strategy for treating patients with fibroproliferative lung diseases.

Correlation of lung function with ultra-low-dose CT-detected lung parenchymal abnormalities: a cohort study of 1344 asbestos exposed individuals

INTRODUCTION

Deliberate exposure to medical ionising radiation should be as low as reasonably practicable but the reduction of radiation from CT should be balanced against diagnostic image quality. The ability of ultra-low-dose CT (uLDCT: similar radiation to chest X-ray) to demonstrate low contrast abnormalities (emphysema and interstitial lung abnormality (ILA)) is unclear.The aim of this cross-sectional study was to analyse the lung parenchymal findings from uLDCT scans against physiological measures of respiratory function.

METHODS

WA Asbestos Review Programme participants were eligible if they had an uLDCT scan and lung function assessment between Janary and December 2018. All scans were performed using a single CT machine and reported using a standardised, semiquantitative synoptic report which includes emphysema and linear fibrosis (ILA) scores.

RESULTS

Of 1344 participants, median (IQR) age was 72.0 (65.0-78.0) years, the majority were males (84.9%) with mixed occupational asbestos exposure (68.1%). There were 721 (53.6%) with no abnormality, 158 (11.8%) with emphysema, 465 (34.6%) with ILA. Mean radiation dose was 0.12 mSv. There was statistically significant between group differences for all physiological parameters of lung function compared with controls. For instance, the emphysema score significantly correlated with obstructive forced expiratory volume in 1 s (FEV₁)/forced vital capacity ratio (r=0.512), per cent predicted FEV₁ (r=0.24) and lower diffusion of carbon monoxide (DLCO) (r=0.337). Multivariate modelling demonstrated that increasing age, emphysema and fibrosis scores predicted reduced DLCO (adjusted R²=0.30).

DISCUSSION

uLDCT-detected parenchymal lung abnormalities correlate strongly with significant changes on lung function testing suggesting the observed CT abnormalities are of physiological and clinical significance.

Pre-Existing Interstitial Lung Abnormalities Are Independent Risk Factors for Interstitial Lung Disease during Durvalumab Treatment after Chemoradiotherapy in Patients with Locally Advanced Non-Small-Cell Lung Cancer

Introduction/Background: Chemoradiotherapy (CRT) followed by durvalumab, an immune checkpoint inhibitor, is the standard treatment for locally advanced non-small-cell lung cancer (NSCLC). Interstitial lung disease (ILD) is a life-threatening toxicity caused by these treatments; however, risk factors for the ILD have not yet been established. Interstitial lung abnormalities (ILAs) are computed tomography (CT) findings which manifest as minor interstitial shadows. We aimed to investigate whether ILAs could be risk factors for grade-two or higher ILD during durvalumab therapy. Patients and Methods: Patients with NSCLC who received durvalumab after CRT from July 2018 to June 2021 were retrospectively enrolled. We obtained patient characteristics, laboratory data, radiotherapeutic parameters, and chest CT findings before durvalumab therapy. Results: A total of 148 patients were enrolled. The prevalence of ILAs before durvalumab treatment was 37.8%. Among 148 patients, 63.5% developed ILD during durvalumab therapy. The proportion of patients with grade-two or higher ILD was 33.8%. The univariate logistic regression analysis revealed that older age, high dose-volume histogram parameters, and the presence of ILAs were significant risk factors for grade-two or higher ILD. The multivariate analysis showed that ILAs were independent risk factors for grade-two or higher ILD (odds ratio, 3.70; 95% confidence interval, 1.69−7.72; p < 0.001). Conclusions: We showed that pre-existing ILAs are risk factors for ILD during durvalumab treatment after CRT. We should pay attention to the development of grade-two or higher ILD during durvalumab treatment in patients with ILAs.

The Association between Exposures and Disease Characteristics in Familial Pulmonary Fibrosis

Rationale: Heterogeneous characteristics are observed in familial pulmonary fibrosis (FPF), suggesting that nongenetic factors contribute to disease manifestations. Objectives: To determine the relationship between environmental exposures and disease characteristics of FPF, including the morphological characteristics on chest computed tomography (CT) scan, and timing of FPF symptom onset, lung transplantation, or death. Methods: Subjects with FPF with an exposure questionnaire and chest CT were selected from a prospective cohort at Vanderbilt. Disease characteristics were defined by lung parenchymal findings on chest CT associated with fibrotic hypersensitivity pneumonitis (fHP) or usual interstitial pneumonia (UIP) and by time from birth to symptom onset or a composite of lung transplantation or death. After assessing the potential for confounding by sex or smoking, adjusted logistic or Cox proportional hazards regression models identified exposures associated with fHP or UIP CT findings. Findings were validated in a cohort of patients with sporadic pulmonary fibrosis enrolled in the LTRC (Lung Tissue Research Consortium) study. Results: Among 159 subjects with FPF, 98 (61.6%) were males and 96 (60.4%) were ever-smokers. Males were less likely to have CT features of fHP, including mosaic attenuation (FPF: adjusted [for sex and smoking] odds ratio [aOR], 0.27; 95% confidence interval [CI], 0.09-0.76; P = 0.01; LTRC: aOR, 0.35; 95% CI, 0.21-0.61; P = 0.0002). Organic exposures, however, were not consistently associated with fHP features in either cohort. Smoking was a risk factor for honeycombing in both cohorts (FPF: aOR, 2.19; 95% CI, 1.12-4.28; P = 0.02; LTRC: aOR, 1.69; 95% CI, 1.22-2.33; P = 0.002). Rock dust exposure may also be associated with honeycombing, although the association was not statistically-significant when accounting for sex and smoking (FPF: aOR, 2.27; 95% CI, 0.997-5.15; P = 0.051; LTRC: aOR, 1.51; 95% CI, 0.97-2.33; P = 0.07). In the FPF cohort, ever-smokers experienced a shorter transplant-free survival (adjusted hazard ratio, 1.64; 95% CI, 1.07-2.52; P = 0.02), whereas sex was not associated with differential survival (male adjusted hazard ratio, 0.75; 95% CI, 0.50-1.14; P = 0.18). Conclusions: In FPF, smoking contributes to shortened transplant-free survival and development of honeycombing, a finding that is also likely applicable to sporadic pulmonary fibrosis. Females are more likely to manifest CT features of fHP (mosaic attenuation), a finding that was incompletely explained by sex differences in exposures. These findings may have implications for pulmonary fibrosis classification and management.

Smoking-related interstitial lung disease

Exposure to smoke is associated with the development of diseases of the airways and lung parenchyma. Apart from chronic obstructive pulmonary disease (COPD), in some individuals, tobacco smoke can also trigger mechanisms of interstitial damage that result in various pathological changes and pulmonary fibrosis. A causal relation has been established between tobacco smoke and a group of entities that includes respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), desquamative interstitial pneumonia (DIP), Langerhans cell histiocytosis (LCH), and acute eosinophilic pneumonia (AEP). Smoking is considered a risk factor for idiopathic pulmonary fibrosis (IPF); however, the role and impact of smoking in the development of this differentiated clinical entity, which has also been called combined pulmonary fibrosis and emphysema (CPFE) as well as nonspecific interstitial pneumonia (NIP), remains to be determined. The definition of smoking-related interstitial fibrosis (SRIF) is relatively recent, with differentiated histological characteristics. The likely interconnection between the mechanisms involved in inflammation and pulmonary fibrosis in all these processes often results in an overlapping of clinical, radiological, and histological features in the same patient that can sometimes lead to radiological patterns of interstitial lung disease that are impossible to classify. For this reason, a combined approach to diagnosis is recommendable. This combined approach should be based on the joint interpretation of the histological and radiological findings while taking the clinical context into consideration. This paper aims to describe the high-resolution computed tomography (HRCT) findings in this group of disease entities in correlation with the clinical manifestations and histological changes underlying the radiological pattern.

Clinical significance of interstitial lung abnormalities and immune checkpoint inhibitor-induced interstitial lung disease in patients with non-small cell lung cancer

BACKGROUND

Interstitial lung abnormalities (ILAs) are known to be a risk of drug-induced pneumonitis. However, there are few reports on the relationship between ILAs and immune checkpoint inhibitor-related interstitial lung disease (ICI-ILD). We retrospectively investigated the clinical significance of ILAs in patients with non-small cell lung cancer (NSCLC) receiving ICIs.

METHODS

We defined ILAs as nondependent abnormalities affecting more than 5% of any lung zone, including ground-glass or diffuse centrilobular nodularities, traction bronchiectasis, honeycombing, and nonemphysematous cysts. Early-onset ICI-ILD was defined as developing within 3 months after the initiation of ICI administration.

RESULTS

Of 264 patients with advanced NSCLC, 57 patients (21.6%) had ILAs (43 fibrotic and 14 nonfibrotic ILAs). The difference between the incidence of ICI-ILD in patients with or without ILAs was not significant. Of 193 patients treated by ICI monotherapy, 18 (9.3%) developed early-onset ICI-ILD. Among patients receiving ICI monotherapy, the incidence of early-onset ICI-ILD was significantly higher in patients with than in patients without nonfibrotic ILAs.

CONCLUSION

The presence of nonfibrotic ILAs is a significant risk for early-onset ICI-ILD in patients with NSCLC undergoing ICI monotherapy. Clinicians should be aware of ILAs, especially nonfibrotic ILAs, before administering ICIs to lung cancer patients.

The HLA-DRB1*07 Allele Is Associated with Interstitial Lung Abnormalities (ILA) and Subpleural Location in a Mexican Mestizo Population

Interstitial lung abnormalities (ILA) are defined as the presence of different patterns of increased lung density, including ground glass attenuation and reticular opacities on chest high-resolution computed tomography (HRCT). In this study, we included 90 subjects with ILA and 189 healthy controls (HC) from our Aging Lung Program. We found that subjects with ILA are older, have a significant smoking history, and have worse pulmonary function than HC (p < 0.05). When we evaluated the allele frequencies of the human leukocyte antigen (HLA) system, we found that HLA-DRB1*07 was associated with a higher risk for ILA (p < 0.05, OR = 1.95, 95% CI = 1.06-3.57). When we compared subjects with subpleural ILA vs. HC, the association with HLA-DRB1*07 became stronger than the whole ILA group (p < 0.05, OR = 2.29, 95% CI = 1.24-4.25). Furthermore, subjects with subpleural ILA and central ILA display differences in allele frequencies with HLA-DRB1*14 (3.33% vs. 13.33%, p < 0.05) and *15 (3.33% vs. 20%, p < 0.05). Our findings indicate that the HLA-DRB1*07 allele contributes to the risk of ILA, especially those of subpleural locations.

Interstitial Lung Abnormalities in Patients With Locally Advanced Esophageal Cancer: Prevalence, Risk Factors, and Clinical Implications

PURPOSE

Interstitial lung abnormalities (ILAs) represent nondependent abnormalities on chest computed tomography (CT) indicating lung parenchymal damages due to inflammation and fibrosis. Interstitial lung abnormalities have been studied as a predictor of clinical outcome in lung cancer, but not in other thoracic malignancies. The present study investigated the prevalence of ILA in patients with esophageal cancer and identified risk factors and clinical implications of ILA in these patients.

METHODS

The study included 208 patients with locally advanced esophageal cancer (median age, 65.6 years; 166 males, 42 females). Interstitial lung abnormality was scored on baseline CT scans before treatment using a 3-point scale (0 = no evidence of ILA, 1 = equivocal for ILA, 2 = ILA). Clinical characteristics and overall survival were compared in patients with ILA (score 2) and others.

RESULTS

An ILA was present in 14 of 208 patients (7%) with esophageal cancer on pretreatment chest CT. Patients with ILA were significantly older (median age, 69 vs 65, respectively; P = 0.011), had a higher number of pack-years of smoking ( P = 0.02), and more commonly had T4 stage disease ( P = 0.026) than patients with ILA score of 1 or 0. Interstitial lung abnormality on baseline scan was associated with a lack of surgical resection after chemoradiotherapy (7/14, 50% vs 39/194, 20% respectively; P = 0.016). Interstitial lung abnormality was not associated with overall survival (log-rank P = 0.75, Cox P = 0.613).

CONCLUSIONS

An ILA was present in 7% of esophageal cancer patients, which is similar to the prevalence in general population and in smokers. Interstitial lung abnormality was strongly associated with a lack of surgical resection after chemoradiotherapy, indicating an implication of ILA in treatment selection in these patients, which can be further studied in larger cohorts.

Interstitial Lung Abnormalities at CT: Subtypes, Clinical Significance, and Associations with Lung Cancer

Interstitial lung abnormality (ILA) is defined as an interstitial change detected incidentally on CT images. It is seen in 4%-9% of smokers and 2%-7% of nonsmokers. ILA has a tendency to progress with time and is associated with respiratory symptoms, decreased exercise capability, reduced pulmonary function, and increased mortality. ILAs can be classified into three subcategories: nonsubpleural, subpleural nonfibrotic, and subpleural fibrotic. In cases of ILA, clinically significant interstitial lung disease should be identified and requires clinically driven management by a pulmonologist. Risk factors for the progression of ILA include clinical elements (ie, inhalation exposures, medication use, radiation therapy, thoracic surgery, physiologic findings, and gas exchange findings) and radiologic elements (ie, basal and peripheral predominance and fibrotic findings). It is recommended that individuals with one or more clinical or radiologic risk factors for progression of ILA be actively monitored with pulmonary function testing and CT. To avoid overcalling ILA at CT, radiologists must recognize the imaging pitfalls, including centrilobular nodularity, dependent abnormality, suboptimal inspiration, osteophyte-related lesions, apical cap and pleuroparenchymal fibroelastosis-like lesions, aspiration, and infection. There is a close association between ILA and lung cancer, and many studies have reported an increased incidence of lung cancer, worse prognoses, and/or increased pulmonary complications in relation to cancer treatment in patients with ILA. ILA is considered to be an important comorbidity in patients with lung cancer. Accordingly, all radiologists involved with body CT must have sound knowledge of ILAs owing to the high prevalence and potential clinical significance of these anomalies. An overview of ILAs, including a literature review of the associations between ILAs and lung cancer, is presented. ©RSNA, 2022.

High Mortality in an Older Japanese Population with Low Forced Vital Capacity and Gender-Dependent Potential Impact of Muscle Strength: Longitudinal Cohort Study

Generally, weak muscle power is associated with high mortality. We aimed to evaluate the unknown association between % predicted value forced vital capacity (FVC% predicted) and mortality in asymptomatic older people, and the impact of muscle power on this association. We analyzed the Tsurugaya cohort that enrolled Japanese people aged ≥70 for 15 years with Cox proportional hazards model. Exposure variables were FVC% predicted and leg power. The outcome was all-cause mortality. The subjects were divided into quartiles by FVC% predicted or leg power, or into two groups by 80% for FVC% predicted or by the strongest 25% for leg power. Across 985 subjects, 262 died. The males with lower FVC% predicted exhibited higher mortality risks. The hazard ratio (HR) was 2.03 (95% CI 1.30−3.18) at the lowest relative to the highest groups. The addition of leg power reduced the HR to 1.78 (95% CI 1.12−2.80). In females, FVC% predicted under 80% was a risk factor and the HR was 1.67 (95% CI 1.05−2.64) without the effect of leg power. In FVC% predicted <80% males HRs were 2.44 (95% CI 1.48−4.02) in weak and 1.38 (95% CI 0.52−3.64) in strong leg power males, relative to ≥80% and strong leg power males. Low FVC% predicted was associated with high mortality with potential unfavorable effects of weak leg power in males.

Traction Bronchiectasis/Bronchiolectasis on CT Scans in Relationship to Clinical Outcomes and Mortality: The COPDGene Study

Background The clinical impact of interstitial lung abnormalities (ILAs) on poor prognosis has been reported in many studies, but risk stratification in ILA will contribute to clinical practice. Purpose To investigate the association of traction bronchiectasis/bronchiolectasis index (TBI) with mortality and clinical outcomes in individuals with ILA by using the COPDGene cohort. Materials and Methods This study was a secondary analysis of prospectively collected data. Chest CT scans of participants with ILA for traction bronchiectasis/bronchiolectasis were evaluated and outcomes were compared with participants without ILA from the COPDGene study (January 2008 to June 2011). TBI was classified as follows: TBI-0, ILA without traction bronchiectasis/bronchiolectasis; TBI-1, ILA with bronchiolectasis but without bronchiectasis or architectural distortion; TBI-2, ILA with mild to moderate traction bronchiectasis; and TBI-3, ILA with severe traction bronchiectasis and/or honeycombing. Clinical outcomes and overall survival were compared among the TBI groups and the non-ILA group by using multivariable linear regression model and Cox proportional hazards model, respectively. Results Overall, 5295 participants (median age, 59 years; IQR, 52-66 years; 2779 men) were included, and 582 participants with ILA and 4713 participants without ILA were identified. TBI groups were associated with poorer clinical outcomes such as quality of life scores in the multivariable linear regression model (TBI-0: coefficient, 3.2 [95% CI: 0.6, 5.7; P = .01]; TBI-1: coefficient, 3.3 [95% CI: 1.1, 5.6; P = .003]; TBI-2: coefficient, 7.6 [95% CI: 4.0, 11; P < .001]; TBI-3: coefficient, 32 [95% CI: 17, 48; P < .001]). The multivariable Cox model demonstrated that ILA without traction bronchiectasis (TBI-0-1) and with traction bronchiectasis (TBI-2-3) were associated with shorter overall survival (TBI-0-1: hazard ratio [HR], 1.4 [95% CI: 1.0, 1.9; P = .049]; TBI-2-3: HR, 3.8 [95% CI: 2.6, 5.6; P < .001]). Conclusion Traction bronchiectasis/bronchiolectasis was associated with poorer clinical outcomes compared with the group without interstitial lung abnormalities; TBI-2 and 3 were associated with shorter survival. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Lee and Im in this issue.

Syndrome of Combined Pulmonary Fibrosis and Emphysema: An Official ATS/ERS/JRS/ALAT Research Statement

Background: The presence of emphysema is relatively common in patients with fibrotic interstitial lung disease. This has been designated combined pulmonary fibrosis and emphysema (CPFE). The lack of consensus over definitions and diagnostic criteria has limited CPFE research. Goals: The objectives of this task force were to review the terminology, definition, characteristics, pathophysiology, and research priorities of CPFE and to explore whether CPFE is a syndrome. Methods: This research statement was developed by a committee including 19 pulmonologists, 5 radiologists, 3 pathologists, 2 methodologists, and 2 patient representatives. The final document was supported by a focused systematic review that identified and summarized all recent publications related to CPFE. Results: This task force identified that patients with CPFE are predominantly male, with a history of smoking, severe dyspnea, relatively preserved airflow rates and lung volumes on spirometry, severely impaired DlCO, exertional hypoxemia, frequent pulmonary hypertension, and a dismal prognosis. The committee proposes to identify CPFE as a syndrome, given the clustering of pulmonary fibrosis and emphysema, shared pathogenetic pathways, unique considerations related to disease progression, increased risk of complications (pulmonary hypertension, lung cancer, and/or mortality), and implications for clinical trial design. There are varying features of interstitial lung disease and emphysema in CPFE. The committee offers a research definition and classification criteria and proposes that studies on CPFE include a comprehensive description of radiologic and, when available, pathological patterns, including some recently described patterns such as smoking-related interstitial fibrosis. Conclusions: This statement delineates the syndrome of CPFE and highlights research priorities.

The Proteomic Profile of Interstitial Lung Abnormalities

Rationale: Knowledge on biomarkers of interstitial lung disease is incomplete. Interstitial lung abnormalities (ILAs) are radiologic changes that may present in its early stages. Objectives: To uncover blood proteins associated with ILAs using large-scale proteomics methods. Methods: Data from two prospective cohort studies, the AGES-Reykjavik (Age, Gene/Environment Susceptibility-Reykjavik) study (N = 5,259) for biomarker discovery and the COPDGene (Genetic Epidemiology of COPD) study (N = 4,899) for replication, were used. Blood proteins were measured using DNA aptamers, targeting more than 4,700 protein analytes. The association of proteins with ILAs and ILA progression was assessed with regression modeling, as were associations with genetic risk factors. Adaptive Least Absolute Shrinkage and Selection Operator models were applied to bootstrap data samples to discover sets of proteins predictive of ILAs and their progression. Measurements and Main Results: Of 287 associations, SFTPB (surfactant protein B) (odds ratio [OR], 3.71 [95% confidence interval (CI), 3.20-4.30]; P = 4.28 × 10^-67), SCGB3A1 (Secretoglobin family 3A member 1) (OR, 2.43 [95% CI, 2.13-2.77]; P = 8.01 × 10^-40), and WFDC2 (WAP four-disulfide core domain protein 2) (OR, 2.42 [95% CI, 2.11-2.78]; P = 4.01 × 10^-36) were most significantly associated with ILA in AGES-Reykjavik and were replicated in COPDGene. In AGES-Reykjavik, concentrations of SFTPB were associated with the rs35705950 MUC5B (mucin 5B) promoter polymorphism, and SFTPB and WFDC2 had the strongest associations with ILA progression. Multivariate models of ILAs in AGES-Reykjavik, ILAs in COPDGene, and ILA progression in AGES-Reykjavik had validated areas under the receiver operating characteristic curve of 0.880, 0.826, and 0.824, respectively. Conclusions: Novel, replicated associations of ILA, its progression, and genetic risk factors with numerous blood proteins are demonstrated as well as machine-learning-based models with favorable predictive potential. Several proteins are revealed as potential markers of early fibrotic lung disease.

Interstitial lung abnormalities are associated with decreased mean telomere length

BACKGROUND

Interstitial lung abnormalities (ILA) share many features with idiopathic pulmonary fibrosis; however, it is not known if ILA are associated with decreased mean telomere length (MTL).

METHODS

Telomere length was measured with quantitative PCR in the Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) and Age Gene/Environment Susceptibility Reykjavik (AGES-Reykjavik) cohorts and Southern blot analysis was used in the Framingham Heart Study (FHS). Logistic and linear regression were used to assess the association between ILA and MTL; Cox proportional hazards models were used to assess the association between MTL and mortality.

RESULTS

In all three cohorts, ILA were associated with decreased MTL. In the COPDGene and AGES-Reykjavik cohorts, after adjustment there was greater than twofold increase in the odds of ILA when comparing the shortest quartile of telomere length to the longest quartile (OR 2.2, 95% CI 1.5-3.4, p=0.0001, and OR 2.6, 95% CI 1.4-4.9, p=0.003, respectively). In the FHS, those with ILA had shorter telomeres than those without ILA (-767 bp, 95% CI 76-1584 bp, p=0.03). Although decreased MTL was associated with chronic obstructive pulmonary disease (OR 1.3, 95% CI 1.1-1.6, p=0.01) in COPDGene, the effect estimate was less than that noted with ILA. There was no consistent association between MTL and risk of death when comparing the shortest quartile of telomere length in COPDGene and AGES-Reykjavik (HR 0.82, 95% CI 0.4-1.7, p=0.6, and HR 1.2, 95% CI 0.6-2.2, p=0.5, respectively).

CONCLUSION

ILA are associated with decreased MTL.

Association of Pulmonary Function With Late-Life Cardiac Function and Heart Failure Risk: The ARIC Study

Background Pulmonary and cardiac functions decline with age, but the associations of pulmonary dysfunction with cardiac function and heart failure (HF) risk in late life is not known. We aimed to determine the associations of percent predicted forced vital capacity (ppFVC) and the ratio of forced expired volume in 1 second (FEV₁) to forced vital capacity (FVC; FEV₁/FVC) with cardiac function and incident HF with preserved or reduced ejection fraction in late life. Methods and Results Among 3854 HF-free participants in the ARIC (Atherosclerosis Risk in Communities) cohort study who underwent echocardiography and spirometry at the fifth study visit (2011-2013), associations of FEV₁/FVC and ppFVC with echocardiographic measures, cardiac biomarkers, and risk of HF, HF with preserved ejection fraction, and HF with reduced ejection fraction were assessed. Multivariable linear and Cox regression models adjusted for demographics, body mass index, coronary disease, atrial fibrillation, hypertension, and diabetes. Mean age was 75±5 years, 40% were men, 19% were Black, and 61% were ever smokers. Mean FEV₁/FVC was 72±8%, and ppFVC was 98±17%. In adjusted analyses, lower FEV₁/FVC and ppFVC were associated with higher NT-proBNP (N-terminal pro-B-type natriuretic peptide; both P<0.001) and pulmonary artery pressure (P<0.004). Lower ppFVC was also associated with higher left ventricular mass, left ventricular filling pressure, and high-sensitivity C-reactive protein (all P<0.01). Lower FEV₁/FVC was associated with a trend toward higher risk of incident HF with preserved ejection fraction (hazard ratio [HR] per 10-point decrease, 1.31; 95% CI, 0.98-1.74; P=0.07) and HF with reduced ejection fraction (HR per 10-point decrease, 1.24; 95% CI, 0.91-1.70; P=0.18), but these associations did not reach statistical significance. Lower ppFVC was associated with incident HF with preserved ejection fraction (HR per 10-unit decrease, 1.21; 95% CI, 1.04-1.41; P=0.013) but not with HF with reduced ejection fraction (HR per 10-unit decrease, 0.90; 95% CI, 0.76-1.07; P=0.24). Conclusions Subclinical reductions in FEV₁/FVC and ppFVC differentially associate with cardiac function and HF risk in late life.

The relationship between interstitial lung abnormalities, mortality, and multimorbidity: a cohort study

BACKGROUND

Interstitial lung abnormalities (ILAs) are associated with increased mortality. It is unclear whether multimorbidity accounts for the mortality association or how strongly ILA is associated with mortality relative to other common age-associated diseases. We determined the association of ILA with all-cause mortality adjusted for multimorbidity, compared mortality associated with ILA and prevalent cardiovascular disease (CVD), diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease and cancer and also determined the association between ILA and these diseases.

METHODS

We measured ILA (none, indeterminant, definite) using blinded reads of CT images, prevalent chronic diseases and potential confounders in two observational cohorts, the Framingham Heart Study (FHS) (n=2449) and Age, Gene/Environment Susceptibility - Reykjavik Study (AGES-Reykjavik) (n=5180). We determined associations with mortality using Cox proportional hazards models and between ILA and diseases with multinomial logistic regression.

RESULTS

Over a median (IQR) follow-up of 8.8 (1.4) years in FHS and 12.0 (7.7) years in AGES-Reykjavik, in adjusted models, ILAs were significantly associated with increased mortality (HR, 95% CI 1.95, 1.23 to 3.08, p=0.0042, in FHS; HR 1.60, 1.41 to 1.82, p<0.0001, in AGES-Reykjavik) adjusted for multimorbidity. In both cohorts, the association of ILA with mortality was of similar magnitude to the association of most other diseases. In adjusted models, ILAs were associated only with prevalent kidney disease (OR, 95% CI 1.90, 1.01 to 3.57, p=0.0452) in FHS and with prevalent CVD (OR 1.42, 1.12 to 1.81, p=0.0040) in AGES-Reykjavik.

CONCLUSIONS

ILAs were associated with mortality adjusted for multimorbidity and were similarly associated with increased mortality compared with several common chronic diseases. ILAs were not consistently associated with the prevalence of these diseases themselves.

Incidental discovery of interstitial lung disease: diagnostic approach, surveillance and perspectives

The incidental discovery of pre-clinical interstitial lung disease (ILD) has led to the designation of interstitial lung abnormalities (ILA), a radiological entity defined as the incidental finding of computed tomography (CT) abnormalities affecting more than 5% of any lung zone. Two recent documents have redefined the borders of this entity and made the recommendation to monitor patients with ILA at risk of progression. In this narrative review, we will focus on some of the limits of the current approach, underlying the potential for progression to full-blown ILD of some patients with ILA and the numerous links between subpleural fibrotic ILA and idiopathic pulmonary fibrosis (IPF). Considering the large prevalence of ILA in the general population (7%), restricting monitoring only to cases considered at risk of progression appears a reasonable approach. However, this suggestion should not prevent pulmonary physicians from pursuing an early diagnosis of ILD and timely treatment where appropriate. In cases of suspected ILD, whether found incidentally or not, the pulmonary physician is still required to make a correct ILD diagnosis according to current guidelines, and eventually treat the patient accordingly.

In patients with interstitial lung abnormalities (ILA), monitoring of those at risk of progression is currently recommended, and pulmonary physicians should pursue an early diagnosis when ILA become clinically significant to facilitate timely treatment https://bit.ly/3HKOQc8

Blood gene expression risk profiles and interstitial lung abnormalities: COPDGene and ECLIPSE cohort studies

BACKGROUND

Interstitial lung abnormalities (ILA) are radiologic findings that may progress to idiopathic pulmonary fibrosis (IPF). Blood gene expression profiles can predict IPF mortality, but whether these same genes associate with ILA and ILA outcomes is unknown. This study evaluated if a previously described blood gene expression profile associated with IPF mortality is associated with ILA and all-cause mortality.

METHODS

In COPDGene and ECLIPSE study participants with visual scoring of ILA and gene expression data, we evaluated the association of a previously described IPF mortality score with ILA and mortality. We also trained a new ILA score, derived using genes from the IPF score, in a subset of COPDGene. We tested the association with ILA and mortality on the remainder of COPDGene and ECLIPSE.

RESULTS

In 1469 COPDGene (training n = 734; testing n = 735) and 571 ECLIPSE participants, the IPF score was not associated with ILA or mortality. However, an ILA score derived from IPF score genes was associated with ILA (meta-analysis of test datasets OR 1.4 [95% CI: 1.2-1.6]) and mortality (HR 1.25 [95% CI: 1.12-1.41]). Six of the 11 genes in the ILA score had discordant directions of effects compared to the IPF score. The ILA score partially mediated the effects of age on mortality (11.8% proportion mediated).

CONCLUSIONS

An ILA gene expression score, derived from IPF mortality-associated genes, identified genes with concordant and discordant effects on IPF mortality and ILA. These results suggest shared, and unique biologic processes, amongst those with ILA, IPF, aging, and death.

Increased monocyte level is a risk factor for radiological progression in patients with early fibrotic interstitial lung abnormality

Background

Interstitial lung abnormalities (ILA) are specific spatial patterns on computed tomography (CT) scan potentially compatible with early interstitial lung disease. A proportion will progress; management involves risk stratification and surveillance. Elevated blood monocyte levels have been shown to associate with progression of idiopathic pulmonary fibrosis. The aims of the present study were: 1) to estimate the proportion of “early fibrotic” (EF)-ILAs (reticular±ground-glass opacities, excluding traction bronchiectasis and honeycombing) on CT scans of patients attending all-indications thoracic CTs, and proportion demonstrating radiological progression; and 2) to explore association between peripheral blood leukocyte levels and ILA progression.

Methods

We analysed all thoracic CT reports in individuals aged 45–75 years performed between January 2015 and December 2020 in one large teaching hospital (Oxford, UK) to identify patient CT reports consistent with EF-ILA. CT-contemporaneous blood leukocyte counts were examined to explore contribution to progression and all-cause mortality, using multivariate Cox regression.

Results

40 711 patients underwent thoracic CT imaging during this period. 1259 (3.1%) demonstrated the EF-ILA pattern (mean±sd age 65.4±7.32 years; 735 (47.8%) male). EF-ILA was significantly associated with all-cause mortality (hazard ratio 1.87, 95% CI 1.25–2.78; p=0.002). 362 cases underwent at least one follow-on CT. Radiological progression was observed in 157 (43.4%) cases: increase in reticulation n=51, new traction bronchiectasis n=84, honeycombing n=22. Monocyte count, neutrophil count, monocyte:lymphocyte ratio, neutrophil:lymphocyte ratio and “systemic inflammatory response index” were significantly associated with radiological progression.

Conclusion

3.1% of subjects requiring thoracic CT during a 6-year period demonstrated EF-ILA. Monocyte levels and blood leukocyte-derived indexes were associated with radiological progression and could indicate which patients may require closer follow-up.

Monocyte levels are associated with radiological progression of early fibrotic ILA to established interstitial lung disease and could indicate which patients might require closer follow-uphttps://bit.ly/3LlS2ff

Incidental chest findings on coronary CT angiography: a pictorial essay and management proposal

Many health systems have been using coronary CT angiography (CCTA) as a first-line examination for ischaemic heart disease patients in various countries. The rising number of CCTA examinations has led to a significant increase in the number of reported incidental extracardiac findings, mainly in the chest. Pulmonary nodules are the most common incidental findings on CCTA scans, as there is a substantial overlap of risk factors between the population seeking to exclude ischaemic heart disease and those at risk of developing lung cancer (i.e., advanced age and smoking habits). However, most incidental findings are clinically insignificant and actively pursuing them could be cost-prohibitive and submit the patient to unnecessary and potentially harmful examinations. Furthermore, there is little consensus regarding when to report or actively exclude these findings and how to manage them, that is, when to trigger an alert or to immediately refer the patient to a pulmonologist, a thoracic surgeon or a multidisciplinary team. This pictorial essay discusses the current literature on this topic and is illustrated with a review of CCTA scans. We also propose a checklist organised by organ and system, recommending actions to raise awareness of pulmonologists, thoracic surgeons, cardiologists and radiologists regarding the most significant and actionable incidental findings on CCTA scans.

Interstitial lung abnormalities and interstitial lung diseases associated with cigarette smoking in a rural cohort undergoing surgical resection

Background

Cigarette smoking is a risk factor for interstitial lung abnormalities (ILAs) and interstitial lung diseases (ILDs). Investigation defining the relationships between ILAs/ILDs and clinical, radiographic, and pathologic findings in smokers have been incomplete. Employing a cohort undergoing surgical resection for lung nodules/masses, we (1) define the prevalence of ILAs/ILDs, (2) delineate their clinical, radiographic and pathologic predictors, and (3) determine their associations with mortality.

Methods

Patients undergoing resection of lung nodules/masses between 2017 and 2020 at a rural Appalachian, tertiary medical center were retrospectively investigated. Predictors for ILAs/ILDs and mortality were assessed using multivariate logistic regression analysis.

Results

In the total study cohort of 352 patients, radiographic ILAs and ILDs were observed in 35.2% and 17.6%, respectively. Among ILA patterns, subpleural reticular changes (14.8%), non-emphysematous cysts, centrilobular (CL) ground glass opacities (GGOs) (8% each), and mixed CL-GGO and subpleural reticular changes (7.4%) were common. ILD patterns included combined pulmonary fibrosis emphysema (CPFE) (3.1%), respiratory bronchiolitis (RB)-ILD (3.1%), organizing pneumonitis (2.8%) and unclassifiable (4.8%). The group with radiographic ILAs/ILDs had a significantly higher proportion of ever smokers (49% vs. 39.9%), pack years of smoking (44.57 ± 36.21 vs. 34.96 ± 26.22), clinical comorbidities of COPD (35% vs. 26.5%) and mildly reduced diffusion capacity (% predicated 66.29 ± 20.55 vs. 71.84 ± 23). Radiographic centrilobular and paraseptal emphysema (40% vs. 22.2% and 17.6% vs. 9.6%, respectively) and isolated traction bronchiectasis (10.2% vs. 4.2%) were associated with ILAs/ILDs. Pathological variables of emphysema (34.9% vs. 18.5%), any fibrosis (15.9% vs. 4.6%), peribronchiolar metaplasia (PBM, 8% vs. 1.1%), RB (10.3% vs. 2.5%), and anthracosis (21.6% vs. 14.5%) were associated with ILAs/ILDs. Histologic emphysema showed positive correlations with any fibrosis, RB, anthracosis and ≥ 30 pack year of smoking. The group with ILAs/ILDs had significantly higher mortality (9.1% vs. 2.2%, OR 4.13, [95% CI of 1.84–9.25]).

Conclusions

In a rural cohort undergoing surgical resection, radiographic subclinical ILAs/ILDs patterns were highly prevalent and associated with ever smoking and intensity of smoking. The presence of radiographic ILA/ILD patterns and isolated honeycomb changes were associated with increased mortality. Subclinical ILAs/ILDs and histologic fibrosis correlated with clinical COPD as well as radiographic and pathologic emphysema emphasizing the co-existence of these pulmonary injuries in a heavily smoking population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01961-9.

Incidental Findings on Low-Dose CT Scan Lung Cancer Screenings and Deaths From Respiratory Diseases

BACKGROUND

Incidental respiratory disease-related findings are frequently observed on low-dose CT (LDCT) lung cancer screenings. This study analyzed data from the National Lung Screening Trial (NLST) to assess the relationship between such findings and respiratory disease mortality (RDM), excluding lung cancer.

RESEARCH QUESTION

Are incidental respiratory findings on LDCT scanning associated with increased RDM?

STUDY DESIGN AND METHODS

Subjects in the NLST LDCT arm received three annual screens. Trial radiologists noted findings related to possible lung cancer, as well as respiratory-related incidental findings. Demographic characteristics, smoking history, and medical history were captured in a baseline questionnaire. Kaplan-Meier curves were used to assess cumulative RDM. Multivariate proportional hazards models were used to assess risk factors for RDM; in addition to incidental CT scan findings, variables included respiratory disease history (COPD/emphysema, and asthma), smoking history, and demographic factors (age, race, sex, and BMI).

RESULTS

Of 26,722 subjects in the NLST LDCT arm, 25,002 received the baseline screen and a subsequent LDCT screen. Overall, 59% were male, 26.5% were aged ≥ 65 years at baseline, and 10.6% reported a history of COPD/emphysema. Emphysema on LDCT scanning was reported in 30.7% of subjects at baseline and in 44.2% at any screen. Of those with emphysema on baseline LDCT scanning, 18% reported a history of COPD/emphysema. Median mortality follow-up was 10.3 years. There were 3,639 deaths, and 708 were from respiratory diseases. Among subjects with no history of COPD/emphysema, 10-year cumulative RDM ranged from 3.9% for subjects with emphysema and reticular opacities to 1.1% for those with neither condition; the corresponding range among subjects with a COPD/emphysema history was 17.3% (both) to 3.7% (neither). Emphysema on LDCT imaging was associated with a significantly elevated RDM hazard ratio (2.27; 95% CI, 1.92-2.7) in the multivariate model. Reticular opacities (including honeycombing/fibrosis/scar) also had a significantly elevated hazard ratio (1.39; 95% CI, 1.19-1.62).

INTERPRETATION

Incidental respiratory disease-related findings observed on NLST LDCT screens were frequent and associated with increased mortality from respiratory diseases.

Associations of sleep duration and sleep-wake rhythm with lung parenchymal abnormalities on computed tomography: The MESA study

Impairment of the circadian rhythm promotes lung inflammation and fibrosis in pre-clinical models. We aimed to examine whether short and/or long sleep duration and other markers of sleep-wake patterns are associated with a greater burden of lung parenchymal abnormalities on computed tomography among adults. We cross-sectionally examined associations of sleep duration captured by actigraphy with interstitial lung abnormalities (n = 1111) and high attenuation areas (n = 1416) on computed tomography scan in the Multi-Ethnic Study of Atherosclerosis at Exam 5 (2010-2013). We adjusted for potential confounders in logistic and linear regression models for interstitial lung abnormalities and high attenuation area, respectively. High attenuation area models were also adjusted for study site, lung volume imaged, radiation dose and stratified by body mass index. Secondary exposures were self-reported sleep duration, sleep fragmentation index, sleep midpoint and chronotype. The mean age of those with longer sleep duration (≥ 8 hr) was 70 years and the prevalence of interstitial lung abnormalities was 14%. Increasing actigraphy-based sleep duration among participants with ≥ 8 hr of sleep was associated with a higher adjusted odds of interstitial lung abnormalities (odds ratio of 2.66 per 1-hr increment, 95% confidence interval 1.42-4.99). Longer sleep duration and higher sleep fragmentation index were associated with greater high attenuation area on computed tomography among participants with a body mass index < 25 kg m-2 (p-value for interaction < 0.02). Self-reported sleep duration, later sleep midpoint and evening chronotype were not associated with outcomes. Actigraphy-based longer sleep duration and sleep fragmentation were associated with a greater burden of lung abnormalities on computed tomography scan.

Associations of Monocyte Count and Other Immune Cell Types with Interstitial Lung Abnormalities

Rationale: Higher blood monocyte counts are associated with worse survival in adults with clinically diagnosed pulmonary fibrosis. Their association with the development and progression of interstitial lung abnormalities (ILA) in humans is unknown. Objectives: We evaluated the associations of blood monocyte count, and other immune cell types, with ILA, high-attenuation areas, and FVC in four independent cohorts. Methods: We included participants with measured monocyte counts and computed tomographic (CT) imaging enrolled in MESA (Multi-Ethnic Study of Atherosclerosis, n = 484), AGES-Reykjavik (Age/Gene Environment Susceptibility Study, n = 3,547), COPDGene (Genetic Epidemiology of COPD, n = 2,719), and the ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points, n = 646). Measurements and Main Results: After adjustment for covariates, a 1-SD increment in blood monocyte count was associated with ILA in MESA (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.0-1.8), AGES-Reykjavik (OR, 1.2; 95% CI, 1.1-1.3), COPDGene (OR, 1.3; 95% CI, 1.2-1.4), and ECLIPSE (OR, 1.2; 95% CI, 1.0-1.4). A higher monocyte count was associated with ILA progression over 5 years in AGES-Reykjavik (OR, 1.2; 95% CI, 1.0-1.3). Compared with participants without ILA, there was a higher percentage of activated monocytes among those with ILA in MESA. Higher monocyte count was associated with greater high-attenuation areas in MESA and lower FVC in MESA and COPDGene. Associations of other immune cell types were less consistent. Conclusions: Higher blood monocyte counts were associated with the presence and progression of interstitial lung abnormalities and lower FVC.

Survival after surgery for clinical stage I non-small-cell lung cancer with interstitial pneumonia

OBJECTIVES

To evaluate the surgical outcomes after surgery in patients with stage I lung cancer and idiopathic interstitial pneumonia (IIP).

MATERIAL AND METHODS

This retrospective cohort study was conducted in 2131 patients with clinical stage I non-small-cell lung cancer (NSCLC) who underwent pulmonary resection between 2009 and 2018. Based on computed tomography (CT) findings, 233 patients had IIP. Lobectomy was performed in 180 patients with IIP and 1227 patients without IIP. Surgical outcomes, recurrence sites, and cause of death were investigated. In addition, we measured the distance between the tumor and hilum in patients with IIP and assessed the feasibility of sublobar resection.

RESULTS

The overall survival and cancer-specific survival of patients with IIP were significantly poorer than those of non-IIP patients. The five-year overall survival rates of patients with clinical stage IA/IB lung cancer with and without IIP were 58.1%/47.3% and 88.8%/68.9%, respectively. Furthermore, 9.4% of patients with IIP and 0.9% of patients without IIP died from respiratory-related causes within 2 years after surgery. Multivariate analyses revealed that volume capacity <80% (odds ratio: 3.259), usual interstitial pneumonia pattern by CT finding (odds ratio: 1.891), and nodal metastasis (odds ratio: 3.304) were prognostic factors for overall survival in patients with IIP. Unexpected nodal metastases were observed in 22.3% of patients with IIP. By CT judgment, sublobar resection was not feasible in 68% of patients with IIP who underwent lobectomy.

CONCLUSIONS

The overall survival of patients with early NSCLC after pulmonary resection with IIP was poor; this is related to the high prevalence of cancer-specific and respiratory-related deaths. Sublobar resection is not always feasible, the procedure on patients with IIP should be selected carefully according to the characteristics of each case. Nodal dissection should be performed to evaluate for metastasis, regardless of the extent of lung resection.

Chest CT-assessed comorbidities and all-cause mortality risk in COPD patients in the BODE cohort

BACKGROUND AND OBJECTIVE

The availability of chest computed tomography (CT) imaging can help diagnose comorbidities associated with chronic obstructive pulmonary disease (COPD). Their systematic identification and relationship with all-cause mortality have not been explored. Furthermore, whether their CT-detected prevalence differs from clinical diagnosis is unknown.

METHODS

The prevalence of 10 CT-assessed comorbidities was retrospectively determined at baseline in 379 patients (71% men) with mild to severe COPD attending pulmonary clinics. Anthropometrics, smoking history, dyspnoea, lung function, exercise capacity, BODE (BMI, Obstruction, Dyspnoea and Exercise capacity) index and exacerbations rate were recorded. The prevalence of CT-determined comorbidities was compared with that recorded clinically. Over a median of 78 months of observation, the independent association with all-cause mortality was analysed. A 'CT-comorbidome' graphically expressed the strength of their association with mortality risk.

RESULTS

Coronary artery calcification, emphysema and bronchiectasis were the most prevalent comorbidities (79.8%, 62.7% and 33.9%, respectively). All were underdiagnosed before CT. Coronary artery calcium (hazard ratio [HR] 2.09; 95% CI 1.03-4.26, p = 0.042), bronchiectasis (HR 2.12; 95% CI 1.05-4.26, p = 0.036) and low psoas muscle density (HR 2.61; 95% CI 1.23-5.57, p = 0.010) were independently associated with all-cause mortality and helped define the 'CT-comorbidome'.

CONCLUSION

This study of COPD patients shows that systematic detection of 10 CT-diagnosed comorbidities, most of which were not detected clinically, provides information of potential use to patients and clinicians caring for them.

Detection and Early Referral of Patients With Interstitial Lung Abnormalities: An Expert Survey Initiative

BACKGROUND

Interstitial lung abnormalities (ILA) may represent undiagnosed early-stage or subclinical interstitial lung disease (ILD). ILA are often observed incidentally in patients who subsequently develop clinically overt ILD. There is limited information on consensus definitions for, and the appropriate evaluation of, ILA. Early recognition of patients with ILD remains challenging, yet critically important. Expert consensus could inform early recognition and referral.

RESEARCH QUESTION

Can consensus-based expert recommendations be identified to guide clinicians in the recognition, referral, and follow-up of patients with or at risk of developing early ILDs?

STUDY DESIGN AND METHODS

Pulmonologists and radiologists with expertise in ILD participated in two iterative rounds of surveys. The surveys aimed to establish consensus regarding ILA reporting, identification of patients with ILA, and identification of populations that might benefit from screening for ILD. Recommended referral criteria and follow-up processes were also addressed. Threshold for consensus was defined a priori as ≥ 75% agreement or disagreement.

RESULTS

Fifty-five experts were invited and 44 participated; consensus was reached on 39 of 85 questions. The following clinically important statements achieved consensus: honeycombing and traction bronchiectasis or bronchiolectasis indicate potentially progressive ILD; honeycombing detected during lung cancer screening should be reported as potentially significant (eg, with the Lung CT Screening Reporting and Data System "S-modifier" [Lung-RADS; which indicates clinically significant or potentially significant noncancer findings]), recommending referral to a pulmonologist in the radiology report; high-resolution CT imaging and full pulmonary function tests should be ordered if nondependent subpleural reticulation, traction bronchiectasis, honeycombing, centrilobular ground-glass nodules, or patchy ground-glass opacity are observed on CT imaging; patients with honeycombing or traction bronchiectasis should be referred to a pulmonologist irrespective of diffusion capacity values; and patients with systemic sclerosis should be screened with pulmonary function tests for early-stage ILD.

INTERPRETATION

Guidance was established for identifying clinically relevant ILA, subsequent referral, and follow-up. These results lay the foundation for developing practical guidance on managing patients with ILA.

Artificial Intelligence for Interstitial Lung Disease Analysis on Chest Computed Tomography: A Systematic Review

RATIONALE AND OBJECTIVES

High-resolution computed tomography (HRCT) is paramount in the assessment of interstitial lung disease (ILD). Yet, HRCT interpretation of ILDs may be hampered by inter- and intra-observer variability. Recently, artificial intelligence (AI) has revolutionized medical image analysis. This technology has the potential to advance patient care in ILD. We aimed to systematically evaluate the application of AI for the analysis of ILD in HRCT.

MATERIALS AND METHODS

We searched MEDLINE/PubMed databases for original publications of deep learning for ILD analysis on chest CT. The search included studies published up to March 1, 2021. The risk of bias evaluation included tailored Quality Assessment of Diagnostic Accuracy Studies and the modified Joanna Briggs Institute Critical Appraisal checklist.

RESULTS

Data was extracted from 19 retrospective studies. Deep learning techniques included detection, segmentation, and classification of ILD on HRCT. Most studies focused on the classification of ILD into different morphological patterns. Accuracies of 78%-91% were achieved. Two studies demonstrated near-expert performance for the diagnosis of idiopathic pulmonary fibrosis (IPF). The Quality Assessment of Diagnostic Accuracy Studies tool identified a high risk of bias in 15/19 (78.9%) of the studies.

CONCLUSION

AI has the potential to contribute to the radiologic diagnosis and classification of ILD. However, the accuracy performance is still not satisfactory, and research is limited by a small number of retrospective studies. Hence, the existing published data may not be sufficiently reliable. Only well-designed prospective controlled studies can accurately assess the value of existing AI tools for ILD evaluation.

Radiologic-pathologic correlation of interstitial lung abnormalities and predictors for progression and survival

OBJECTIVES

To evaluate radiologic and histologic correlations for interstitial lung abnormalities (ILAs) and to investigate radiologic or pathologic features contributing to disease progression and mortality.

METHODS

From 268 patients who underwent surgical lung biopsy between January 2004 and April 2019, 45 patients with incidentally detected ILA and normal pulmonary function were retrospectively included. CT features were classified as subpleural fibrotic or non-fibrotic, and changes in ILA over at least 2 years of follow-up were evaluated. Histologic findings were categorized as definite, probable, indeterminate, or alternative diagnosis for usual interstitial pneumonia (UIP) patterns. Overall and progression-free survival were calculated using the Kaplan-Meier method, and the Cox proportional hazard method was used to examine predictors for ILA progression and survival.

RESULTS

Among 36 subpleural fibrotic ILA subjects, 25 (69%) showed definite or probable UIP patterns, and 89% (8/9) of subpleural non-fibrotic ILA subjects showed an indeterminate or alternative diagnosis for UIP pattern on histopathology. On the radiologic-pathologic correlation, reticular opacity of fibrotic ILA was correlated with patchy involvement of fibrosis, and ground-glass attenuation of non-fibrotic ILA corresponded to diffuse interstitial thickening. The median progression time of ILA was 54 months, and fibrotic ILA increased the likelihood of progression (hazard ratio, 2.42; p = 0.017). The median survival time of ILA subjects was 123 months, and fibrotic ILA was associated with an increased risk of death (hazard ratio, 9.22; p = 0.025).

CONCLUSIONS

Subpleural fibrotic ILAs are associated with pathologic UIP patterns, and it is important to recognize subpleural fibrotic ILA on CT to predict disease progression and mortality.

KEY POINTS

• In total, 69% of subpleural fibrotic ILA showed definite or probable UIP patterns, while 11% of subpleural non-fibrotic ILA showed definite or probable UIP patterns. • Subpleural fibrotic ILA was associated with an increased rate of progression (hazard ratio, 2.42; p = 0.017), and the median progression-free time was 40 months. • Subpleural fibrotic ILA had an increased risk of death (hazard ratio, 9.22; p = 0.025), and the median survival time was 86 months.

Association Between Preserved Ratio Impaired Spirometry and Clinical Outcomes in US Adults

Importance

Chronic lung diseases are a leading cause of morbidity and mortality. Unlike chronic obstructive pulmonary disease, clinical outcomes associated with proportional reductions in expiratory lung volumes without obstruction, otherwise known as preserved ratio impaired spirometry (PRISm), are poorly understood.

Objective

To examine the prevalence, correlates, and clinical outcomes associated with PRISm in US adults.

Design, Setting, and Participants

The National Heart, Lung, and Blood Institute (NHLBI) Pooled Cohorts Study was a retrospective study with harmonized pooled data from 9 US general population-based cohorts (enrollment, 65 251 participants aged 18 to 102 years of whom 53 701 participants had valid baseline lung function) conducted from 1971-2011 (final follow-up, December 2018).

Exposures

Participants were categorized into mutually exclusive groups by baseline lung function. PRISm was defined as the ratio of forced expiratory volume in the first second to forced vital capacity (FEV1:FVC) greater than or equal to 0.70 and FEV1 less than 80% predicted; obstructive spirometry FEV1:FVC ratio of less than 0.70; and normal spirometry FEV1:FVC ratio greater than or equal to 0.7 and FEV1 greater than or equal to 80% predicted.

Main Outcomes and Measures

Main outcomes were all-cause mortality, respiratory-related mortality, coronary heart disease (CHD)-related mortality, respiratory-related events (hospitalizations and mortality), and CHD-related events (hospitalizations and mortality) classified by adjudication or validated administrative criteria. Absolute risks were adjusted for age and smoking status. Poisson and Cox proportional hazards models comparing PRISm vs normal spirometry were adjusted for age, sex, race and ethnicity, education, body mass index, smoking status, cohort, and comorbidities.

Results

Among all participants (mean [SD] age, 53.2 [15.8] years, 56.4% women, 48.5% never-smokers), 4582 (8.5%) had PRISm. The presence of PRISm relative to normal spirometry was significantly associated with obesity (prevalence, 48.3% vs 31.4%; prevalence ratio [PR], 1.68 [95% CI, 1.55-1.82]), underweight (prevalence, 1.4% vs 1.0%; PR, 2.20 [95% CI, 1.72-2.82]), female sex (prevalence, 60.3% vs 59.0%; PR, 1.07 [95% CI, 1.01-1.13]), and current smoking (prevalence, 25.2% vs 17.5%; PR, 1.33 [95% CI, 1.22-1.45]). PRISm, compared with normal spirometry, was significantly associated with greater all-cause mortality (29.6/1000 person-years vs 18.0/1000 person-years; difference, 11.6/1000 person-years [95% CI, 10.0-13.1]; adjusted hazard ratio [HR], 1.50 [95% CI, 1.42-1.59]), respiratory-related mortality (2.1/1000 person-years vs 1.0/1000 person-years; difference, 1.1/1000 person-years [95% CI, 0.7-1.6]; adjusted HR, 1.95 [95% CI, 1.54-2.48]), CHD-related mortality (5.4/1000 person-years vs 2.6/1000 person-years; difference, 2.7/1000 person-years [95% CI, 2.1-3.4]; adjusted HR, 1.55 [95% CI, 1.36-1.77]), respiratory-related events (12.2/1000 person-years vs 6.0/1000 person-years; difference, 6.2/1000 person-years [95% CI, 4.9-7.5]; adjusted HR, 1.90 [95% CI, 1.69-2.14]), and CHD-related events (11.7/1000 person-years vs 7.0/1000 person-years; difference, 4.7/1000 person-years [95% CI, 3.7-5.8]; adjusted HR, 1.30 [95% CI, 1.18-1.42]).

Conclusions and Relevance

In a large, population-based sample of US adults, baseline PRISm, compared with normal spirometry, was associated with a small but statistically significant increased risk for mortality and adverse cardiovascular and respiratory outcomes. Further research is needed to explore whether this association is causal.

Screening for preclinical parenchymal lung disease in rheumatoid arthritis

OBJECTIVES

Pulmonary disease is a common extraarticular manifestation of RA associated with increased morbidity and mortality. No current strategies exist for screening this at-risk population for parenchymal lung disease, including emphysema and interstitial lung disease (ILD).

METHODS

RA patients without a diagnosis of ILD or chronic obstructive pulmonary disease underwent prospective and comprehensive clinical, laboratory, functional and radiological evaluations. High resolution CT (HRCT) scans were scored for preclinical emphysema and preclinical ILD and evaluated for other abnormalities.

RESULTS

Pulmonary imaging and/or functional abnormalities were identified in 78 (74%) of 106 subjects; 45% had preclinical parenchymal lung disease. These individuals were older with lower diffusion capacity but had similar smoking histories compared with no disease. Preclinical emphysema (36%), the most commonly detected abnormality, was associated with older age, higher anti-cyclic citrullinated peptide antibody titres and diffusion abnormalities. A significant proportion of preclinical emphysema occurred among never smokers (47%) with a predominantly panlobular pattern. Preclinical ILD (15%) was not associated with clinical, laboratory or functional measures.

CONCLUSION

We identified a high prevalence of undiagnosed preclinical parenchymal lung disease in RA driven primarily by isolated emphysema, suggesting that it may be a prevalent and previously unrecognized pulmonary manifestation of RA, even among never smokers. As clinical, laboratory and functional evaluations did not adequately identify preclinical parenchymal abnormalities, HRCT may be the most effective screening modality currently available for patients with RA.

Monocyte and neutrophil levels are potentially linked to progression to IPF for patients with indeterminate UIP CT pattern

RATIONALE

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with poor prognosis. Identifying patients early may allow intervention which could limit progression. The 'indeterminate for usual interstitial pneumonia' (iUIP) CT pattern, defined in the 2018 IPF guidelines, could be a precursor to IPF but there is limited data on how patients with iUIP progress over time.

OBJECTIVE

To evaluate the radiological progression of iUIP and explore factors linked to progression to IPF.

METHODS

We performed a retrospective analysis of a lung fibrosis clinic cohort (n=230) seen between 2013 and 2017. Cases with iUIP were identified; first ever CTs for each patient found and categorised as 'non-progressor' or 'progressors' (the latter defined as increase in extent of disease or to 'definite' or 'probable' UIP CT pattern) during their follow-up. Lung function trends, haematological data and patient demographics were examined to explore disease evolution and potential contribution to progression.

RESULTS

48 cases with iUIP CT pattern were identified. Of these, 32 had follow-up CT scans, of which 23 demonstrated progression. 17 patients in this cohort were diagnosed with IPF over a mean (SD) period of 3.9 (±1.9) years. Monocyte (HR: 23, 95% CI: 1.6 to 340, p=0.03) and neutrophil levels (HR: 1.8, 95% CI: 1.3 to 2.3, p<0.001), obtained around the time of initial CT, were associated with progression to IPF using Cox proportional hazard modelling.

CONCLUSION

53% of our evaluable patients with iUIP progressed to IPF over a mean of 4 years. Monocyte and neutrophil levels at initial CT were significantly associated with progression in disease. These data provide a single-centre analysis of the evolution of patients with iUIP CT pattern, and first signal for potential factors associated with progression to IPF.

Interstitial lung abnormalities - current knowledge and future directions

Efforts to grasp the significance of radiologic changes similar to interstitial lung disease (ILD) in undiagnosed individuals have intensified in the recent decade. The term interstitial lung abnormalities (ILA) is an emerging definition of such changes, defined by visual examination of computed tomography scans. Substantial insights have been made in the origins and clinical consequences of these changes, as well as automated measures of early lung fibrosis, which will likely lead to increased recognition of early fibrotic lung changes among clinicians and researchers alike.

Interstitial lung abnormalities have an estimated prevalence of 7–10% in elderly populations. They correlate with many ILD risk factors, both epidemiologic and genetic. Additionally, histopathological similarities with IPF exist in those with ILA. While no established blood biomarker of ILA exists, several have been suggested. Distinct imaging patterns indicating advanced fibrosis correlate with worse clinical outcomes. ILA are also linked with adverse clinical outcomes such as increased mortality and risk of lung cancer.

Progression of ILA has been noted in a significant portion of those with ILA and is associated with many of the same features as ILD, including advanced fibrosis. Those with ILA progression are at risk of accelerated FVC decline and increased mortality. Radiologic changes resembling ILD have also been attained by automated measures. Such measures associate with some, but not all the same factors as ILA.

ILA and similar radiologic changes are in many ways analogous to ILD and likely represent a precursor of ILD in some cases. While warranting an evaluation for ILD, they are associated with poor clinical outcomes beyond possible ILD development and thus are by themselves a significant finding. Among the present objectives of this field are the stratification of patients with regards to progression and the discovery of biomarkers with predictive value for clinical outcomes.

Interstitial Lung Abnormalities, Emphysema and Spirometry in Smokers

BACKGROUND

Most pulmonary conditions reduce forced vital capacity (FVC), but studies of patients with combined pulmonary fibrosis and emphysema demonstrate that reductions in FVC are less than expected when these two conditions coexist clinically.

RESEARCH QUESTION

Do interstitial lung abnormalities (ILA), chest computed tomography (CT) imaging findings that may suggest an early stage of pulmonary fibrosis in undiagnosed individuals, affect the association between emphysema and FVC?

STUDY DESIGN AND METHODS

Measures of ILA and emphysema were available in 9579 and 5277 participants from phases 1 (2007-2011) and 2 (2012-2016) of COPDGene, respectively. ILA were defined by Fleischner Society guidelines. Adjusted linear regression models were used to assess the associations and interactions between ILA, emphysema, measures of spirometry and lung function.

RESULTS

ILA were present in 528 (6%), and 580 (11%), of participants in phases 1 and 2 of COPDGene, respectively. ILA modified the association between emphysema and FVC (P<0.0001 for interaction) in both phases. In phase 1, in those without ILA, a 5% increase in emphysema was associated with a reduction in FVC (-110 cc, 95% confidence interval [CI] -121, -100; P<0.0001) however, in those with ILA it was not (-11cc, 95% CI -53,31; P=0.59). In contrast, there was no interaction between ILA and emphysema on total lung capacity (TLC) nor on diffusing capacity of carbon monoxide (DLCO).

INTERPRETATION

The presence of ILA attenuates the reduction in FVC associated with emphysema.

Familial Pulmonary Fibrosis: Genetic Features and Clinical Implications

Pulmonary fibrosis comprises a wide range of fibrotic lung diseases with unknown pathogenesis and poor prognosis. Familial pulmonary fibrosis (FPF) represents a unique subgroup of patients in which at least one other relative is also affected. Patients with FPF exhibit a wide range of pulmonary fibrosis phenotypes, although idiopathic pulmonary fibrosis is the most common subtype. Despite variable disease manifestations, patients with FPF experience worse survival compared with their counterparts with the sporadic disease form. Therefore, ascertaining a positive family history not only provides prognostic value but should also raise suspicion for the inheritance of an underlying causative genetic variant within kindreds. By focusing on FPF kindreds, rare variants within surfactant metabolism and telomere maintenance genes have been discovered. However, such genetic variation is not solely restricted to FPF, as similar rare variants are found in patients with seemingly sporadic pulmonary fibrosis, further supporting the idea of genetic susceptibility underlying pulmonary fibrosis as a whole. Researchers are beginning to show how the presence of rare variants may inform clinical management, such as informing predisposition risk for yet unaffected relatives as well as informing prognosis and therapeutic strategy for those already affected. Despite these advances, rare variants in surfactant and telomere-related genes only explain the genetic basis in about one-quarter of FPF kindreds. Therefore, research is needed to identify the missing genetic contributors of pulmonary fibrosis, which would not only improve our understanding of disease pathobiology but may offer additional opportunities to improve the health of patients.