Diagnoses and treatments for participants with interstitial lung abnormalities detected in the Yorkshire Lung Screening Trial

INTRODUCTION

Interstitial lung abnormalities (ILA) are relatively common incidental findings in participants undergoing low-dose CT screening for lung cancer. Some ILA are transient and inconsequential, but others represent interstitial lung disease (ILD). Lung cancer screening therefore offers the opportunity of earlier diagnosis and treatment of ILD for some screening participants.

METHODS

The prevalence of ILA in participants in the baseline screening round of the Yorkshire Lung Screening Trial is reported, along with the proportion referred to a regional ILD service, eventual diagnoses, outcomes and treatments.

RESULTS

Of 6650 participants undergoing screening, ILA were reported in 169 (2.5%) participants. Following review in a screening review meeting, 56 participants were referred to the ILD service for further evaluation (0.8% of all screening participants). 2 participants declined referral, 1 is currently awaiting review and the remaining 53 were confirmed as having ILD. Eventual diagnoses were idiopathic pulmonary fibrosis (n=14), respiratory bronchiolitis ILD (n=4), chronic hypersensitivity pneumonitis (n=2), connective tissue disease/rheumatoid arthritis-related ILD (n=4), asbestosis (n=1), idiopathic non-specific interstitial pneumonia (n=1), sarcoidosis (n=1) and pleuroparenchymal fibroelastosis (n=1). Twenty five patients had unclassifiable idiopathic interstitial pneumonia. Overall, 10 people received pharmacotherapy (7 antifibrotics and 3 prednisolone) representing 18% of those referred to the ILD service and 0.15% of those undergoing screening. 32 people remain under surveillance in the ILD service, some of whom may require treatment in future.

DISCUSSION

Lung cancer screening detects clinically significant cases of ILD allowing early commencement of disease-modifying treatment in a proportion of participants. This is the largest screening cohort to report eventual diagnoses and treatments and provides an estimate of the level of clinical activity to be expected by ILD services as lung cancer screening is implemented. Further research is needed to clarify the optimal management of screen-detected ILD.

TRIAL REGISTRATION NUMBER

ISRCTN42704678.

Tobacco smoking is associated with combined pulmonary fibrosis and emphysema and worse outcomes in interstitial lung disease

Tobacco smoking is an established cause of pulmonary disease whose contribution to interstitial lung disease (ILD) is incompletely characterized. We hypothesized that compared with nonsmokers, subjects who smoked tobacco would differ in their clinical phenotype and have greater mortality. We performed a retrospective cohort study of tobacco smoking in ILD. We evaluated demographic and clinical characteristics, time to clinically meaningful lung function decline (LFD), and mortality in patients stratified by tobacco smoking status (ever vs. never) within a tertiary center ILD registry (2006-2021) and replicated mortality outcomes across four nontertiary medical centers. Data were analyzed by two-sided t tests, Poisson generalized linear models, and Cox proportional hazard models adjusted for age, sex, forced vital capacity (FVC), diffusion capacity of the lung for carbon monoxide (DLCO), ILD subtype, antifibrotic therapy, and hospital center. Of 1,163 study participants, 651 were tobacco smokers. Smokers were more likely to be older, male, have idiopathic pulmonary fibrosis (IPF), coronary artery disease, CT honeycombing and emphysema, higher FVC, and lower DLCO than nonsmokers (P < 0.01). Time to LFD in smokers was shorter (19.7 ± 20 mo vs. 24.8 ± 29 mo; P = 0.038) and survival time was decreased [10.75 (10.08-11.50) yr vs. 20 (18.67-21.25) yr; adjusted mortality HR = 1.50, 95%CI 1.17-1.92; P < 0.0001] compared with nonsmokers. Smokers had 12% greater odds of death for every additional 10 pack yr of smoking (P < 0.0001). Mortality outcomes remained consistent in the nontertiary cohort (HR = 1.51, 95%CI = 1.03-2.23; P = 0.036). Tobacco smokers with ILD have a distinct clinical phenotype strongly associated with the syndrome of combined PF and emphysema, shorter time to LFD, and decreased survival. Smoking prevention may improve ILD outcomes.NEW & NOTEWORTHY Smoking in ILD is associated with combined pulmonary fibrosis and emphysema and worse clinical outcomes.

Interstitial lung disease with and without progressive fibrosing phenotype in patients with idiopathic inflammatory myopathies: data from a large multicentric cohort

OBJECTIVES

Patients with connective tissue diseases can develop interstitial lung disease (ILD), leading to a progressive fibrosing ILD (PF-ILD) phenotype in some cases. We aimed to investigate the occurrence of PF-ILD in idiopathic inflammatory myopathies (IIMs), and factors potentially predicting this phenotype. Secondary aims were to assess the radiological pattern and factors associated with IIMs-ILD.

METHODS

Patients with IIMs from our multicentric prospective cohort were retrospectively evaluated. Data were recorded at IIMs and ILD diagnosis, and during follow-up. Patients with ILD were classified according to the predominant high-resolution CT (HRCT) pattern: non-specific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP) and organising pneumonia (OP). PF-ILD was defined according to the 2022 American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS) and Latin American Thoracic Society (ALAT) guidelines. Univariate and multivariate analyses were performed to identify factors associated to ILD and to PF-ILD.

RESULTS

Of 253 patients with IIMs, 125 (49%) had ILD: 99 (78%) at IIMs diagnosis and 26 (22%) during follow-up (21/26 within 5 years). Multivariate analysis identified anti-Jo-1, anti-MDA5, anti-Ro52, high score on manual muscle test, mechanic's hands and Raynaud's phenomenon as independently associated with ILD. The predominant HRCT pattern was NSIP (50% of patients), followed by UIP (28%) and OP (22%). At 1-year follow-up, PF-ILD occurred in 18% of IIMs-ILD. PF-ILD was predicted by anti-MDA5, heliotropic rash, xerostomia and xerophthalmia at univariate but not at multivariate analysis.

CONCLUSION

Patients with IIM should be carefully screened for ILD at IIMs diagnosis and yearly during follow-up. All patients with IIMs-ILD should be carefully monitored to capture ILD progression since a consistent proportion of them are expected to develop PF-ILD.

SARS-CoV-2 accessory proteins involvement in inflammatory and profibrotic processes through IL11 signaling

SARS-CoV-2, the cause of the COVID-19 pandemic, possesses eleven accessory proteins encoded in its genome. Their roles during infection are still not completely understood. In this study, transcriptomics analysis revealed that both WNT5A and IL11 were significantly up-regulated in A549 cells expressing individual accessory proteins ORF6, ORF8, ORF9b or ORF9c from SARS-CoV-2 (Wuhan-Hu-1 isolate). IL11 is a member of the IL6 family of cytokines. IL11 signaling-related genes were also differentially expressed. Bioinformatics analysis disclosed that both WNT5A and IL11 were involved in pulmonary fibrosis idiopathic disease and functional assays confirmed their association with profibrotic cell responses. Subsequently, data comparison with lung cell lines infected with SARS-CoV-2 or lung biopsies from patients with COVID-19, evidenced altered profibrotic gene expression that matched those obtained in this study. Our results show ORF6, ORF8, ORF9b and ORF9c involvement in inflammatory and profibrotic responses. Thus, these accessory proteins could be targeted by new therapies against COVID-19 disease.

Reply: Confounding in Mendelian randomisation studies

We thank J.J. Lawrence and R. Kumar for their comments, which express concerns regarding our findings of a causal effect of gastro-oesophageal reflux disease (GORD) on idiopathic pulmonary fibrosis (IPF) [1], as this gives us the opportunity to further discuss the issue of confounding in Mendelian randomisation (MR).

Mendelian randomisation (MR) overcomes classical confounding issues that beset observational studies. “Horizontal” but not “vertical” pleiotropy can bias MR study findings but we found no evidence that it was present in our MR analysis of GORD on IPF. https://bit.ly/3Jn7aeq

Gait speed in idiopathic pulmonary fibrosis: Quickly stepping in the right direction

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Inhibition of Fatty Acid Amide Hydrolase (FAAH) Regulates NF-kb Pathways Reducing Bleomycin-Induced Chronic Lung Inflammation and Pulmonary Fibrosis

The deadly interstitial lung condition known as idiopathic pulmonary fibrosis (IPF) worsens over time and for no apparent reason. The traditional therapy approaches for IPF, which include corticosteroids and immunomodulatory drugs, are often ineffective and can have noticeable side effects. The endocannabinoids are hydrolyzed by a membrane protein called fatty acid amide hydrolase (FAAH). Increasing endogenous levels of endocannabinoid by pharmacologically inhibiting FAAH results in numerous analgesic advantages in a variety of experimental models for pre-clinical pain and inflammation. In our study, we mimicked IPF by administering intratracheal bleomycin, and we administered oral URB878 at a dose of 5 mg/kg. The histological changes, cell infiltration, pro-inflammatory cytokine production, inflammation, and nitrosative stress caused by bleomycin were all reduced by URB878. Our data clearly demonstrate for the first time that the inhibition of FAAH activity was able to counteract not only the histological alteration bleomycin-induced but also the cascade of related inflammatory events.

Serum antibodies to peptidylarginine deiminase-4 in rheumatoid arthritis associated-interstitial lung disease are associated with decreased lung fibrosis and improved survival

OBJECTIVE

Interstitial lung disease (ILD) is a leading cause of mortality in rheumatoid arthritis (RA), particularly in those with the usual interstitial pneumonia subtype (RA-UIP). Serum antibodies to peptidylarginine deiminase type 4 (anti-PAD4), particularly a subset that cross-react with PAD3 (PAD3/4XR), have been associated with imaging evidence of ILD. We aimed to determine the specificity of anti-PAD4 antibodies in RA-ILD and to examine associations with markers of ILD severity.

METHODS

48 RA-ILD and 31 idiopathic pulmonary fibrosis (IPF) patients were identified from the National Jewish Health Biobank. RA-ILD subtype was defined by imaging pattern on high-resolution chest computed tomography (CT), and serum was tested for anti-PAD4 and anti-PAD3/4XR antibodies. Antibody prevalence, measures of ILD severity (% predicted forced vital capacity, FVC; % predicted diffusion capacity carbon monoxide, DLCO; quantitative CT fibrosis) and mortality were compared between groups.

RESULTS

Anti-PAD4 antibodies were present in 9/48 (19%) subjects with RA-ILD and no subjects with IPF. Within RA-ILD, anti-PAD4 antibodies were found almost exclusively in RA-UIP (89%). Within RA-UIP subjects, % predicted FVC was higher in anti-PAD4+ subjects, and this finding was most strongly associated with anti-PAD3/4XR antibodies. In addition, quantitative CT fibrosis score was lower in anti-PAD4+ RA-UIP subjects, including those with mono-reactive anti-PAD4 antibodies and anti-PAD3/4XR antibodies. Anti-PAD4+ RA-UIP subjects also exhibited decreased mortality.

CONCLUSIONS

We demonstrate the presence of serum anti-PAD4 antibodies in a subset of patients with RA-UIP that were notably associated with better lung function, less fibrosis and decreased mortality.

PCSK6 and Survival in Idiopathic Pulmonary Fibrosis

Rationale: Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by limited treatment options and high mortality. A better understanding of the molecular drivers of IPF progression is needed. Objectives: To identify and validate molecular determinants of IPF survival. Methods: A staged genome-wide association study was performed using paired genomic and survival data. Stage I cases were drawn from centers across the United States and Europe and stage II cases from Vanderbilt University. Cox proportional hazards regression was used to identify gene variants associated with differential transplantation-free survival (TFS). Stage I variants with nominal significance (P < 5 × 10-5) were advanced for stage II testing and meta-analyzed to identify those reaching genome-wide significance (P < 5 × 10-8). Downstream analyses were performed for genes and proteins associated with variants reaching genome-wide significance. Measurements and Main Results: After quality controls, 1,481 stage I cases and 397 stage II cases were included in the analysis. After filtering, 9,075,629 variants were tested in stage I, with 158 meeting advancement criteria. Four variants associated with TFS with consistent effect direction were identified in stage II, including one in an intron of PCSK6 (proprotein convertase subtilisin/kexin type 6) reaching genome-wide significance (hazard ratio, 4.11 [95% confidence interval, 2.54-6.67]; P = 9.45 × 10-9). PCSK6 protein was highly expressed in IPF lung parenchyma. PCSK6 lung staining intensity, peripheral blood gene expression, and plasma concentration were associated with reduced TFS. Conclusions: We identified four novel variants associated with IPF survival, including one in PCSK6 that reached genome-wide significance. Downstream analyses suggested that PCSK6 protein plays a potentially important role in IPF progression.

Sex- and Race-Based Differences in the Treatment of Interstitial Lung Diseases in North America and Australasia

BACKGROUND

Biological sex, gender, and race are important considerations in patients with interstitial lung diseases (ILDs).

RESEARCH QUESTION

Does a patient's sex assigned at birth, and race, influence ILD treatment initiation?

STUDY DESIGN AND METHODS

Patients with ILD from three longitudinal prospective registries were compared in this observational study. ILD-related medications included antifibrotics and immunomodulating medications. Race was dichotomized as "White" vs "non-White." Time to treatment initiation was determined from the date of the initial ILD registry visit to the date of first medication initiation. Proportions of treated patients were compared between groups by χ2 test. Cox proportional analysis was used to determine how sex and race were associated with time to treatment initiation stratified by ILD diagnosis.

RESULTS

A total of 4,572 patients were included across all cohorts. The proportion of men who received treatment was higher than for women in the Canadian cohort (47% vs 40%; P < .001), and the proportion of White patients who received treatment was also higher compared with non-White patients (46% vs 36%; P < .001). In contrast, the proportion of treated men in the Chicago cohort was lower compared with women (56% vs 64%; P = .005), and that of White patients was lower compared with non-White patients (56% vs 69%; P < .001). No sex- or race-based differences in proportions of patients treated were found in the Australasian cohort. White race was significantly associated with earlier treatment initiation compared with non-White race across diagnoses in the Canadian cohort, whereas the opposite association was found in the Australasian cohort.

INTERPRETATION

Sex- and race-based differences exist in the initiation of ILD treatment, with variability across different cohorts in different countries. Reasons for these differences need to be further explored in future studies.

Tanreqing injection protects against bleomycin-induced pulmonary fibrosis via inhibiting STING-mediated endoplasmic reticulum stress signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Idiopathic pulmonary fibrosis (IPF), characterized by excessive collagen deposition, is a progressive and typically fatal lung disease without effective therapeutic methods. Tanreqing injection (TRQ), a Traditional Chinese Patent Medicine, has been widely used to treat inflammatory respiratory diseases clinically.

AIM OF THE STUDY

The present work aims to elucidate the therapeutic effects and the possible mechanism of TRQ against pulmonary fibrosis.

METHODS

The pulmonary fibrosis murine model were constructed by the intratracheal injection of bleomycin (BLM). 7 days later, TRQ-L (2.6 ml/kg) and TRQ-H (5.2 ml/kg) were administered via intraperitoneal injection respectively for 21 days. The efficacy and underlying molecular mechanism of TRQ were investigated.

RESULTS

Here, we showed that TRQ significantly inhibited BLM-induced lung edema and pulmonary function. TRQ markedly reduced BLM-promoted inflammatory cell infiltration in BALF and inflammatory cytokines release (TNF-α, IL-6, and IL-1β) in serum and lung tissues. Meanwhile, TRQ also alleviated BLM-induced collagen synthesis and deposition. Simultaneously, TRQ attenuated BLM-induced pulmonary fibrosis through regulating the expression of fibrotic hallmarks, manifested by down-regulated α-SMA and up-regulated E-cadherin. Moreover, we found that TRQ significantly prevented STING, p-P65, BIP, p-PERK, p-eIF2α, and ATF4 expression in lung fibrosis mice.

CONCLUSIONS

Taken together, our results indicated that TRQ positively affects inflammatory responses and lung fibrosis by regulating STING-mediated endoplasmic reticulum stress (ERS) signal pathway.

Hesperidin inhibits lung fibroblast senescence via IL-6/STAT3 signaling pathway to suppress pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal lung disease with obscure pathogenesis. Increasing evidence suggests that cellular senescence is an important mechanism underlying in IPF. Clinical treatment with drugs, such as pirfenidone and nintedanib, reduces the risk of acute exacerbation and delays the decline of pulmonary function in patients with mild to moderate pulmonary fibrosis, and with adverse reactions. Hesperidin was previously shown to alleviate pulmonary fibrosis in rats by attenuating the inflammation response. Our previous research indicated that the Citrus alkaline extracts, hesperidin as the main active ingredient, could exert anti-pulmonary fibrosis effects by inhibiting the senescence of lung fibroblasts. However, whether hesperidin could ameliorate pulmonary fibrosis by inhibiting fibroblast senescence needed further study.

PURPOSE

This work aimed to investigate whether and how hesperidin can inhibit lung fibroblast senescence and thereby alleviate pulmonary fibrosis METHODS: Bleomycin was used to establish a mouse model of pulmonary fibrosis and doxorubicin was used to establish a model of cellular senescence in MRC-5 cells in vitro. The therapeutic effects of hesperidin on pulmonary fibrosis using haematoxylin-eosin staining, Masson staining, enzyme-linked immunosorbent assay, immunohistochemistry, western blotting and quantitative Real-Time PCR. The anti-senescent effect of hesperidin in vivo and in vitro was assessed by western blotting, quantitative Real-Time PCR and senescence-associated β-galactosidase RESULTS: We demonstrated that hesperidin could alleviate bleomycin-induced pulmonary fibrosis in mice. The expression level of senescence marker proteins p53, p21, and p16 was were downregulated, along with the myofibroblast marker α-SMA. The number of senescence-associated β-galactosidase-positive cells was significantly reduced by hesperidin intervention in vivo and in vitro. In addition, hesperidin could inhibit the IL6/STAT3 signaling pathway. Furthermore, suppression of the IL-6/STAT3 signaling pathway by pretreatment with the IL-6 inhibitor LMT-28 attenuating effect of hesperidin on fibroblast senescence in vitro.

CONCLUSIONS

These data illustrated that hesperidin may be potentially used in the treatment of IPF based on its ability to inhibit lung fibroblast senescence.

Pulmonary vessel volume in idiopathic pulmonary fibrosis compared with healthy controls aged > 50 years

Idiopathic pulmonary fibrosis (IPF) is characterised by progressive fibrosing interstitial pneumonia with an associated irreversible decline in lung function and quality of life. IPF prevalence increases with age, appearing most frequently in patients aged > 50 years. Pulmonary vessel-like volume (PVV) has been found to be an independent predictor of mortality in IPF and other interstitial lung diseases, however its estimation can be impacted by artefacts associated with image segmentation methods and can be confounded by adjacent fibrosis. This study compares PVV in IPF patients (N = 21) with PVV from a healthy cohort aged > 50 years (N = 59). The analysis includes a connected graph-based approach that aims to minimise artefacts contributing to calculation of PVV. We show that despite a relatively low extent of fibrosis in the IPF cohort (20% of the lung volume), PVV is 2-3 times higher than in controls. This suggests that a standardised method to calculate PVV that accounts for tree connectivity could provide a promising tool to provide early diagnostic or prognostic information in IPF patients and other interstitial lung disease.

A novel prognostic index based on the analysis of glycolysis-related genes in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a lung disease that is both chronic and progressive and is characterized by glycolysis. However, glycolysis's function and its clinical significance in IPF are still not well understood. We accessed the Gene Expression Omnibus database to retrieve mRNA expression information for lung tissue and other samples. We identified genes associated with glycolysis that had differential expression levels between IPF and controls. In this work, we conducted a comprehensive bioinformatic analysis to systematically examine the glycolysis-associated genes with differential expression and subsequently investigated the possible prognostic significance of these genes. Additionally, the expression profiles of the associated prognostic genes were further investigated via quantitative real-time polymerase chain reaction in our cohort. In this investigation, we found that the expression of 16 genes involved in glycolysis was differentially expressed. Among them, 12 were upregulated and 4 were downregulated. We found that 3 glycolysis-related genes (stanniocalcin 2, transketolase like 1, artemin) might serve as hub genes for anticipating patient prognosis. The data from these genes were used to generate the prognostic models. The findings confirmed that high-risk IPF patients recorded a shorter overall survival relative to low-risk patients. This prognostic model yielded 1-, 2-, and 3-year survival rates of 0.666, 0.651, and 0.717, correspondingly, based on the area under the curve of the survival-dependent receiver operating characteristic. The GSE27957 and GSE70866 cohorts validated these findings, indicating the model has a good predictive performance. All 3 glycolysis-associated genes were validated to be expressed in our cohort. Finally, we used mRNA levels from 3 genes to produce a nomogram to quantitatively predict the prognosis of IPF individuals. As possible indicators for the prognosis of IPF, the glycolysis-related genes stanniocalcin 2, transketolase like 1, and artemin were shown to be promising candidate markers.

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.

Incidence and Progression of Fibrotic Lung Disease in an At-Risk Cohort

Rationale: Relatives of patients with familial interstitial pneumonia (FIP) are at increased risk for pulmonary fibrosis and develop preclinical pulmonary fibrosis (PrePF). Objectives: We defined the incidence and progression of new-onset PrePF and its relationship to survival among first-degree relatives of families with FIP. Methods: This is a cohort study of family members with FIP who were initially screened with a health questionnaire and chest high-resolution computed tomography (HRCT) scan, and approximately 4 years later, the evaluation was repeated. A total of 493 asymptomatic first-degree relatives of patients with FIP were evaluated at baseline, and 296 (60%) of the original subjects participated in the subsequent evaluation. Measurements and Main Results: The median interval between HRCTs was 3.9 years (interquartile range, 3.5-4.4 yr). A total of 252 subjects who agreed to repeat evaluation were originally determined not to have PrePF at baseline; 16 developed PrePF. A conservative estimate of the annual incidence of PrePF is 1,023 per 100,000 person-years (95% confidence interval, 511-1,831 per 100,000 person-years). Of 44 subjects with PrePF at baseline, 38.4% subjects had worsening dyspnea compared with 15.4% of those without PrePF (P = 0.002). Usual interstitial pneumonia by HRCT (P < 0.0002) and baseline quantitative fibrosis score (P < 0.001) are also associated with worsening dyspnea. PrePF at the initial screen is associated with decreased survival (P < 0.001). Conclusions: The incidence of PrePF in this at-risk population is at least 100-fold higher than that reported for sporadic idiopathic pulmonary fibrosis (IPF). Although PrePF and IPF represent distinct entities, our study demonstrates that PrePF, like IPF, is progressive and associated with decreased survival.

Combination of computed tomography imaging pattern and severity of respiratory failure as factors associated with prognosis for acute exacerbation of idiopathic chronic fibrosing interstitial pneumonia

BACKGROUND AND OBJECTIVES

The prognosis of idiopathic chronic fibrotic interstitial pneumonitis (CFIP) in patients with acute exacerbation (AE) is variable. We examined whether the imaging pattern on thoracic computed tomography (CT) or the severity of respiratory failure with AE-CFIP is associated with short-term prognosis.

METHODS

Patients admitted to two university hospitals were retrospectively analyzed and divided into derivation and validation cohorts. The distribution of newly appearing parenchymal abnormalities on thoracic CT was classified into peripheral, multifocal, and diffuse patterns. Respiratory failure was defined as severe if a fraction of inspired oxygen ≥ 0.5 was required to maintain percutaneous oxygen saturation ≥ 90% on admission. Factors associated with 90 day-mortality were analyzed using univariate and Cox proportional hazard regression.

RESULTS

In 59 patients with AE-CFIP of the derivation cohort, diffuse pattern on CT was associated with higher mortality within 90 days (43%) than peripheral/multifocal pattern (17%, p = 0.03). Additionally, compared with non-severe failure, severe respiratory failure was associated with higher mortality (47% vs. 21%, p = 0.06). Cox proportional hazard regression analysis demonstrated that a combination of diffuse pattern on CT and severe respiratory failure was associated with the poorest prognosis (hazard ratio [HR] 3.51 [interquartile range 1.26-9.80], p = 0.016) in the derivation cohort, which was confirmed in the validation cohort (n = 31, HR 4.30 [interquartile range 1.51-12.2], p = 0.006).

CONCLUSION

The combination of imaging pattern on thoracic CT and severity of respiratory failure was associated with the prognosis of idiopathic AE-CFIP.