Eur Respir J. 2021 Apr 29:2000653. doi: 10.1183/13993003.00653-2020. Online ahead of print.

ABSTRACT

INTRODUCTION: A reduction in pulmonary artery (PA) relaxation is a key event in pulmonary arterial hypertension (PAH) pathogenesis. CFTR dysfunction in airway epithelial cells plays a central role in cystic fibrosis (CF); CFTR is also expressed in PAs and has been shown to control endothelium-independent relaxation.

AIM AND OBJECTIVES: We aimed to delineate the role of CFTR in PAH pathogenesis through observational and interventional experiments in human tissues and animal models.

METHODS AND RESULTS: RT-Q-PCR, confocal imaging and electron microscopy showed that CFTR expression was reduced in PAs from patients with idiopathic PAH (iPAH) and in rats with monocrotaline-induced pulmonary hypertension (PH). Moreover, using myograph on human, pig and rat PAs, we demonstrated that CFTR activation induces PAs relaxation. CFTR-mediated PA relaxation was reduced in PAs from iPAH patients and rats with monocrotaline- or chronic hypoxia-induced PH. Long-term in vivo CFTR inhibition in rats significantly increased right ventricular systolic pressure, which was related to exaggerated pulmonary vascular cell proliferation in situ and vessel neomuscularization. Pathologic assessment of lungs from patients with severe CF (F508del-CFTR) revealed severe PA remodeling with intimal fibrosis and medial hypertrophy. Lungs from homozygous F508delCftr rats exhibited pulmonary vessel neomuscularization. The elevations in right ventricular systolic pressure and end diastolic pressure in monocrotaline-exposed rats with chronic CFTR inhibition were more prominent than those in vehicle-exposed rats.

CONCLUSIONS: CFTR expression is strongly decreased in PA smooth muscle and endothelial cells in human and animal models of PH. CFTR inhibition increases vascular cell proliferation and strongly reduces PA relaxation.

PMID:33926975 | DOI:10.1183/13993003.00653-2020

Cells. 2021 Apr 28;10(5):1045. doi: 10.3390/cells10051045.

ABSTRACT

Background: Extracellular vesicles (EVs) are secreted by cells from their membrane within circulation and body fluids. Knowledge of the involvement of EVs in pathogenesis of lung diseases is increasing. The present study aimed to evaluate the expression of exosomal surface epitopes in a cohort of idiopathic pulmonary fibrosis (IPF) patients followed in two Italian Referral Centres for Interstitial Lung Diseases, comparing them with a group of healthy volunteers. Materials and Methods: Ninety IPF patients (median age and interquartile range (IQR) 71 (66-75) years; 69 males) were selected retrospectively. Blood samples were obtained from patients before starting antifibrotic therapy. A MACSPlex Exosome Kit, human, (Miltenyi Biotec, Bergisch-Gladbach, Germany), to detect 37 exosomal surface epitopes, was used. Results: CD19, CD69, CD8, and CD86 were significantly higher in IPF patients than in controls (p = 0.0023, p = 0.0471, p = 0.0082, and p = 0.0143, respectively). CD42a was lower in IPF subjects than in controls (p = 0.0153), while CD209, Cd133/1, MCSP, and ROR1 were higher in IPF patients than in controls (p = 0.0007, p = 0.0050, p = 0.0139, and p = 0.0335, respectively). Kaplan-Meier survival analysis for IPF patients: for median values and a cut-off of 0.48 for CD25, the two subgroups showed a significant difference in survival rate (p = 0.0243, hazard ratio: 0.52 (95%CI 0.29-0.92); the same was true for CD8 (cut-off 1.53, p = 0.0309, hazard ratio: 1.39 (95%CI 0.75-2.53). Conclusion: Our multicenter study showed for the first time the expression of surface epitopes on EVs from IPF patients, providing interesting data on the communication signatures/exosomal profile in serum from IPF patients and new insights into the pathogenesis of the disease and a promising reliability in predicting mid-term survival of IPF patients.

PMID:33925174 | DOI:10.3390/cells10051045

Diagnostics (Basel). 2021 Apr 13;11(4):693. doi: 10.3390/diagnostics11040693.

ABSTRACT

Idiopathic interstitial pneumonia (IIP) entails a variable group of lung diseases of unknown etiology. Idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, interstitial lung diseases related to connective tissue disease (CTD-ILD), and hypersensitivity pneumonitis (HP) can manifest with similar clinical, radiological, and histopathological features. In a differential diagnosis, biomarkers can play a significant role. We assume that levels of specific cyto- or chemokines or their receptors can signal pathogenetic processes in the lungs. Eighty patients with different types of idiopathic interstitial pneumonia were enrolled in this study. Cell counts and concentrations of tumor necrosis factor (TNF)-α, interleukin-4 receptor α, proteinase-activated receptor (PAR)-2, matrix metalloproteinase (MMP)-7, and B cell-activating factor were measured in bronchoalveolar lavage fluid using commercial ELISA kits. High resolution computer tomography results were evaluated using alveolar and interstitial (IS) score scales. Levels of TNF-α were significantly higher in HP compared to fibrosing IIP (p < 0.0001) and CTD-ILD (p = 0.0381). Concentrations of IL-4Rα, PAR-2, and MMP-7 were positively correlated with IS (p = 0.0009; p = 0.0256; p = 0.0015, respectively). Since TNF-α plays a major role in inflammation, our results suggest that HP is predominantly an inflammatory disease. From the positive correlation with IS we believe that IL-4Rα, PAR-2, and MMP-7 could serve as fibroproliferative biomarkers in differential diagnosis of IIP.

PMID:33924683 | DOI:10.3390/diagnostics11040693

Biomedicines. 2021 Apr 20;9(4):442. doi: 10.3390/biomedicines9040442.

ABSTRACT

The interest in the lung microbiome and virome and their contribution to the pathogenesis, perpetuation and progression of idiopathic pulmonary fibrosis (IPF) has been increasing during the last decade. The utilization of high-throughput sequencing to detect microbial and/or viral genetic material in bronchoalveolar lavage fluid or lung tissue samples has amplified the ability to identify and quantify specific microbial and viral populations. In stable IPF, higher microbial burden is associated with worse prognosis but no specific microbe has been identified to contribute to this. Additionally, no causative relation has been established. Regarding viral infections, although in the past they have been associated with IPF, causation has not been proved. Although in the past the diagnosis of acute exacerbation of IPF (AE-IPF) was not considered in patients with overt infection, this was amended in the last few years and infection is considered a cause for exacerbation. Besides this, a higher microbial burden has been found in the lungs of patients with AE-IPF and an association with higher morbidity and mortality has been confirmed. In contrast, an association of AE-IPF with viral infection has not been established. Despite the progress during the last decade, a comprehensive knowledge of the microbiome and virome in IPF and their role in disease pathogenesis are yet elusive. Although association with disease severity, risk for progression and mortality has been established, causation has not been proven and the potential use as a biomarker or the benefits of antimicrobial therapeutic strategies are yet to be determined.

PMID:33924195 | DOI:10.3390/biomedicines9040442

Diagnostics (Basel). 2021 Apr 23;11(5):762. doi: 10.3390/diagnostics11050762.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing interstitial lung disease (ILD). This prospective observational study aimed at the evaluation of any correlation between genetic variants associated with IPF susceptibility and high-resolution computed tomography (HRCT) patterns. It also aimed at evidencing any differences in the HRTC pattern between the familial and sporadic form at diagnosis and after two years.

METHODS: A total of 65 IPF patients (mean age at diagnosis 65 ± 10) were enrolled after having given written informed consent. HRCT and genetic evaluations were performed.

RESULTS: A total of 19 familial (mean age 62 ± 15) and 46 sporadic (mean age 70 ± 9) IPF patients were enrolled. A statistically significant difference was evidenced in the HRTC pattern at diagnosis between the two groups. Sporadic IPF patients had a predominantly usual interstitial pneumonia (UIP) pattern compared with those patients with familial IPF (60.0% vs. 21.1%, respectively). Moreover, familial IPF patients had more alternative diagnoses than those with sporadic IPF (31.6% vs. 2.2%, respectively). Furthermore, there was a slight increase in the typical UIP pattern in the familial IPF group at two years from diagnosis.

CONCLUSIONS: Genetic factors play a pivotal role in the risk of developing IPF. However, further studies are required to clarify how these genetic factors may guide clinical treatment decisions.

PMID:33922858 | DOI:10.3390/diagnostics11050762

Biomedicines. 2021 Apr 22;9(5):458. doi: 10.3390/biomedicines9050458.

ABSTRACT

The search for biomarkers that can help to establish an early diagnosis and prognosis of interstitial lung disease (ILD) is of potential interest. VEGF polymorphisms have been implicated in the development of several lung disorders. Consequently, we assessed, for the first time, the role of VEGF polymorphisms in the susceptibility and severity of ILD. A total of 436 Caucasian ILD patients (244 with idiopathic interstitial pneumonias (IIPs) and 192 with non-IIP) and 536 ethnically-matched healthy controls were genotyped for VEGF rs833061, rs1570360, rs2010963, rs3025020, and rs3025039 polymorphisms by TaqMan assays. Pulmonary function tests were collected from all the patients. VEGF serum levels were determined by ELISA in a subgroup of patients. No VEGF genotype, allele, carrier, or haplotype differences were found between ILD patients and controls as well as between IIP and non-IIP patients. However, an association of rs1570360 with IIP in women and also with lung function in IIP patients was found. None of the VEGF polymorphisms were associated with VEGF levels. In conclusion, our results suggest that VEGF does not seem to play a relevant role in ILD, although rs1570360 may influence the severity of ILD in women and a worse outcome in IIP patients.

PMID:33922301 | DOI:10.3390/biomedicines9050458

Metabolites. 2021 Apr 22;11(5):258. doi: 10.3390/metabo11050258.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a serious lung disease characterized by excessive collagen matrix deposition and extracellular remodeling. Signaling pathways mediated by fibrotic cytokine transforming growth factor β1 (TGF-β1) make important contributions to pulmonary fibrosis, but it remains unclear how TGF-β1 alters metabolism and modulates the activation and differentiation of pulmonary fibroblasts. We found that TGF-β1 lowers NADH and NADH/NAD levels, possibly due to changes in the TCA cycle, resulting in reductions in the ATP level and oxidative phosphorylation in pulmonary fibroblasts. In addition, we showed that butyrate (C4), a short chain fatty acid (SCFA), exhibits potent antifibrotic activity by inhibiting expression of fibrosis markers. Butyrate treatment inhibited mitochondrial elongation in TGF-β1-treated lung fibroblasts and increased the mitochondrial membrane potential (MMP). Consistent with the mitochondrial observations, butyrate significantly increased ADP, ATP, NADH, and NADH/NAD levels in TGF-β1-treated pulmonary fibroblasts. Collectively, our findings indicate that TGF-β1 induces changes in mitochondrial dynamics and energy metabolism during myofibroblast differentiation, and that these changes can be modulated by butyrate, which enhances mitochondrial function.

PMID:33922080 | DOI:10.3390/metabo11050258

Cells. 2021 Apr 14;10(4):897. doi: 10.3390/cells10040897.

ABSTRACT

Macrophages play an important role in the innate and adaptive immune responses of organ systems, including the lungs, to particles and pathogens. Cumulative results show that macrophages contribute to the development and progression of acute or chronic inflammatory responses through the secretion of inflammatory cytokines/chemokines and the activation of transcription factors in the pathogenesis of inflammatory lung diseases, such as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), ARDS related to COVID-19 (coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)), allergic asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF). This review summarizes the functions of macrophages and their associated underlying mechanisms in the development of ALI, ARDS, COVID-19-related ARDS, allergic asthma, COPD, and IPF and briefly introduces the acute and chronic experimental animal models. Thus, this review suggests an effective therapeutic approach that focuses on the regulation of macrophage function in the context of inflammatory lung diseases.

PMID:33919784 | DOI:10.3390/cells10040897

J Clin Med. 2021 Apr 1;10(7):1427. doi: 10.3390/jcm10071427.

ABSTRACT

Identification of prognostic and predictive biomarkers in idiopathic pulmonary fibrosis (IPF) could aid assessment of disease severity and prediction of progression and response to treatment. This analysis examined reference ranges for neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) in IPF, and the relationship between NLR or PLR changes and clinical outcomes over 12 months. This post hoc analysis included patients with IPF from the Phase III, double-blind trials of pirfenidone, ASCEND (NCT01366209) and CAPACITY (NCT00287716 and NCT00287729). The relationship between change from baseline to Month 12 in NLR or PLR (divided into quartiles (Q1-Q4)) and outcomes (mortality, respiratory hospitalization, declines in lung function, exercise capacity and quality of life) was assessed. Estimated reference ranges at baseline for all patients analyzed (n = 1334) were 1.1-6.4 for NLR and 56.8-250.5 for PLR. Significant trends were observed across NLR and PLR quartiles for all outcomes in placebo-treated patients, with patients manifesting the greatest NLR or PLR changes experiencing the worst outcomes. These results suggest that the greatest NLR or PLR changes over 12 months were associated with worse clinical outcomes. Further research is needed to determine the utility of NLR and PLR as prognostic biomarkers in IPF.

PMID:33916077 | DOI:10.3390/jcm10071427

FASEB J. 2021 May;35(5):e21599. doi: 10.1096/fj.202002686RR.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease of unknown etiology with minimal treatment options. Repetitive alveolar epithelial injury has been suggested as one of the causative mechanisms of this disease. Type 2 alveolar epithelial cells (AEC2) play a crucial role during fibrosis by functioning as stem cells able to repair epithelial damage. The DNA demethylase Tet methylcytosine dioxygenase 2 (TET2) regulates the stemness of multiple types of stem cells, but whether it also affects the stemness of AEC2 during fibrosis remains elusive. To study the role of TET2 in AEC2 during fibrosis, we first determined TET2 protein levels in the lungs of IPF patients and compared TET2 expression in AEC2 of IPF patients and controls using publicly available data sets. Subsequently, pulmonary fibrosis was induced by the intranasal administration of bleomycin to wild-type and AEC2-specific TET2 knockout mice to determine the role of TET2 in vivo. Fibrosis was assessed by hydroxyproline analysis and fibrotic gene expression. Additionally, macrophage recruitment and activation, and epithelial injury were analyzed. TET2 protein levels and gene expression were downregulated in IPF lungs and AEC2, respectively. Bleomycin inoculation induced a robust fibrotic response as indicated by increased hydroxyproline levels and increased expression of pro-fibrotic genes. Additionally, increased macrophage recruitment and both M1 and M2 activation were observed. None of these parameters were, however, affected by AEC2-specific TET2 deficiency. TET2 expression is reduced in IPF, but the absence of TET2 in AEC2 cells does not affect the development of bleomycin-induced pulmonary fibrosis.

PMID:33913570 | DOI:10.1096/fj.202002686RR

Respirology. 2021 Apr 28. doi: 10.1111/resp.14063. Online ahead of print.

ABSTRACT

The year 2020 was one like no other, as we witnessed the far-reaching impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) global pandemic. Yet despite an unprecedented and challenging year, global research in interstitial lung disease (ILD) continued to break new grounds. Research progress has led to an improved understanding in new diagnostic tools and potential biomarkers for ILD. Studies on the role of antifibrotic therapies, newer therapeutic agents, supportive care strategies and the impact of coronavirus disease 2019 (COVID-19) continue to reshape the management landscape of ILD. In this concise review, we aim to summarize the key studies published in 2020, highlighting their impact on the various aspects of ILD.

PMID:33913200 | DOI:10.1111/resp.14063

Front Pharmacol. 2021 Apr 12;12:639574. doi: 10.3389/fphar.2021.639574. eCollection 2021.

ABSTRACT

Idiopathic pulmonary fibrosis is a progressive lung disease with high mortality and limited therapy that is characterized by epithelial cell damage and fibroblast activation. Ellagic acid is a natural polyphenol compound widely found in fruits and nuts that has multiple pharmacological activities. In this study, we explored the potential effects and mechanisms of Ellagic acid on pulmonary fibrosis in vivo and in vitro. In vivo studies showed that Ellagic acid significantly alleviated bleomycin (BLM)-induced pulmonary fibrosis in mice. In vitro experiments indicated that Ellagic acid could suppress Wnt signaling and attenuate Wnt3a-induced myofibroblast activation and the phosphorylation of Erk2 and Akt. Further studies showed that Ellagic acid could induce autophagy formation in myofibroblasts mainly by suppressing mTOR signaling and promoting apoptosis of myofibroblasts. In vivo experiments revealed that Ellagic acid significantly inhibited myofibroblast activation and promoted autophagy formation. Taken together, our results show that Ellagic acid effectively attenuates BLM-induced pulmonary fibrosis in mice by suppressing myofibroblast activation and promoting autophagy and apoptosis of myofibroblasts by inhibiting the Wnt signaling pathway.

PMID:33912053 | PMC:PMC8072668 | DOI:10.3389/fphar.2021.639574

Front Med. 2021 Apr;15(2):313-329. doi: 10.1007/s11684-020-0737-1. Epub 2021 Apr 27.

ABSTRACT

The medical fungus Hirsutella sinensis has been used as a Chinese folk health supplement because of its immunomodulatory properties. Our previous studies established the antifibrotic action of Hirsutella sinensis mycelium (HSM) in the lung. The epithelial-mesenchymal transition (EMT) is involved in the pathogenesis of idiopathic pulmonary fibrosis. The present study investigates the role of HSM in mediating EMT during the development of pulmonary fibrosis. HSM significantly inhibits bleomycin (BLM)-induced pulmonary fibrosis by blocking the EMT. In addition, the expression levels of midkine are increased in the lungs of the BLM-induced group. Further analysis of the results indicates that the mRNA level of midkine correlated positively with EMT. HSM markedly abrogates the transforming growth factor β-induced EMT-like phenotype and behavior in vitro. The activation of midkine related signaling pathway is ameliorated following HSM treatment, whereas this extract also caused an effective attenuation of the induction of EMT (caused by midkine overexpression) in vitro. Results further confirm that oral medication of HSM disrupted the midkine pathway in vivo. Overall, findings suggest that the midkine pathway and the regulation of the EMT may be considered novel candidate therapeutic targets for the antifibrotic effects caused by HSM.

PMID:33908025 | DOI:10.1007/s11684-020-0737-1

Sci Rep. 2021 Apr 27;11(1):9120. doi: 10.1038/s41598-021-88718-2.

ABSTRACT

Acute exacerbation (AE) in idiopathic pulmonary fibrosis (IPF) is a major prognostic determinant. However, evidence for its prognostic strength is mainly based on the results of small cohort studies with statistical limitations. This retrospective study, which included 108 patients with a first episode of AE-IPF, aimed to identify prognostic factors and to develop prognostic classification models. Multivariate Cox regression analysis revealed that a lower percent-predicted forced vital capacity within 12 months before AE onset (baseline %FVC) and a lower PaO2/FiO2 ratio at AE onset were independent mortality predictors. If the value of each predictor was lower than the cutoff determined by receiver-operating characteristic analysis, 1 point was assigned. Classification of patients into mild, moderate, and severe groups based on total score showed post-AE 90-day cumulative survival rates of 83.3%, 66.2%, and 22.2%, respectively (model 1: C-index 0.702). Moreover, a decision tree-based model was created with the recursive partitioning method using baseline %FVC and PaO2/FiO2 ratio at AE onset from among multivariable; accordingly, patients were classified into 3 groups with post-AE 90-day cumulative survival rates of 84.1%, 64.3%, and 24.0%, respectively (model 2: C-index 0.735). These models can guide clinicians in determining therapeutic strategies and help design future studies on AE-IPF.

PMID:33907284 | DOI:10.1038/s41598-021-88718-2

Medicine (Baltimore). 2021 Apr 30;100(17):e25631. doi: 10.1097/MD.0000000000025631.

ABSTRACT

BACKGROUND: Interstitial lung disease (ILD) has a poor prognosis and lacks specific biomarkers for early diagnosis, assessment of disease severity, and prognosis. YKL-40 levels were found to be elevated in patients with ILD, but these results are inconsistent. Therefore, we conducted a systematic review and meta-analysis to accurately study the relation between YKL-40 and ILD.

METHODS: We performed a systematic literature search in many databases (PubMed, Embase, the China National Knowledge Infrastructure, and Wanfang databases) and commercial Internet search engines to identify studies involving the role of YKL-40 in patients with ILD. The weighted mean difference with its 95% confidence interval were used to investigate the effect sizes. If obvious heterogeneity was found in the meta-analysis, the level of YKL-40 was directly compared by the Mann-Whitney test.

RESULTS: Sixteen eligible articles were finally identified. The results showed that the serum YKL-40 levels of patients with idiopathic pulmonary fibrosis, connective tissue-related ILD, sarcoidosis, cryptogenic tissue pneumonia, asbestosis-ILD, and idiopathic nonspecific interstitial pneumonia were higher than those in controls, but there was no increase in patients with pulmonary alveolar proteinosis. We also found that there are certain differences in the serum YKL-40 levels in patients with different types of ILD. The results showed that the bronchoalveolar lavage fluid YKL-40 levels of patients with idiopathic pulmonary fibrosis were significantly higher than that in controls. A systematic review indicated that there were correlations between the serum YKL-40 levels and lung function in patients with different ILD. In addition, YKL-40 may be used as a valuable biomarker for survival, with risk ratios ranging from 1.006 to 10.9.

CONCLUSIONS: This study suggests that YKL-40 may be a useful biomarker for the diagnosis and prognosis of ILD.

PMID:33907118 | DOI:10.1097/MD.0000000000025631

Chest. 2021 Apr 24:S0012-3692(21)00762-5. doi: 10.1016/j.chest.2021.04.037. Online ahead of print.

ABSTRACT

BACKGROUND: Hypoxemia is a cardinal feature of fibrotic interstitial lung disease (ILD). The incidence, progression, and prognostic significance of hypoxemia in patients with fibrotic ILD is currently unknown.

RESEARCH QUESTION: What are the epidemiology of hypoxemia and its additive prognostic value in current risk prediction model in fibrotic ILD?

METHODS: We identified 848 patients with fibrotic ILD (258 with idiopathic pulmonary fibrosis (IPF)) in five prospective ILD registries from Australia, Canada, and Switzerland. Cumulative incidence of exertional and resting hypoxemia from the time of diagnosis was estimated at 1-year intervals in patients with baseline 6-minute walk tests, adjusted for competing risks of death and lung transplantation. Likelihood ratio tests were used to determine the prognostic significance of exertional and resting hypoxemia for 1-year mortality/transplantation when added to the ILD-GAP model. The cohort was divided into derivation and validation subsets to evaluate performance characteristics of the extended model (the "ILD-GAP-O2" model), which included oxygenation status as a predictor.

RESULTS: The 1-, 2-, and 5-year overall cumulative incidence was 6.1%, 17.3%, and 40.1% for exertional hypoxemia, and 2.4%, 5.6%, and 16.5% for resting hypoxemia, which were significantly higher in IPF patients compared to non-IPF patients (p<0.001 for both). Addition of exertional or resting hypoxemia to the ILD-GAP model improved 1-year mortality/transplantation prediction (p<0.001 for both). The ILD-GAP-O2 model had improved discrimination (C-index of 0.80 vs 0.75) and model fit (Akaike information criteria of 400 vs 422) in the validation cohort, with comparable calibration.

INTERPRETATION: IPF patients have higher cumulative incidence of exertional and resting hypoxemia than non-IPF patients. The extended ILD-GAP-O2 model provides additional risk stratification for 1-year prognosis in fibrotic ILD.

PMID:33905679 | DOI:10.1016/j.chest.2021.04.037

Chest. 2021 Apr 24:S0012-3692(21)00760-1. doi: 10.1016/j.chest.2021.04.035. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with unknown etiology. A limited number of small studies showed an effect of tobacco smoking on risk for IPF, but second-hand smoking has not been examined.

RESEARCH QUESTION: Are smoking-related exposures associated with risk for IPF, and is there any interaction between them?

STUDY DESIGN AND METHODS: We designed a prospective cohort study in UK Biobank, including 437,453 non-related men and women of white ethnic background (aged 40 to 69 at baseline). We assessed the effect of tobacco smoking-related exposures on risk for IPF using Cox regression adjusted for age, sex, Townsend deprivation index, and home area population density. We also examined for potential additive and multiplicative interaction between these exposures. Multiple imputation with chained equations was used to deal with missing data.

RESULTS: We identified 802 incident IPF cases. We showed an association between smoking status (HR, 2.12; 95% CI, 1.81-2.47), maternal smoking (HR, 1.38; 95% CI, 1.18-1.62) and smoking in household (HR, 1.26; 95% CI, 1.02-1.57) with risk for IPF in the multivariable model. In ever smokers, a dose-response relationship was observed between pack-years of smoking and risk of IPF (HR per 1 pack-year increase, 1.013; 95% CI, 1.009-1.016). Furthermore, an additive and multiplicative interaction was observed between maternal smoking and smoking status with a relative excess risk due to interaction of 1.00 (95% CI, 0.45-1.54) and a ratio of HR of 1.50 (95% CI, 1.05-2.14).

INTERPRETATION: Active and passive tobacco smoking have an independent detrimental effect on risk of IPF and work synergistically. Also, intensity of smoking presents a dose-response association with IPF, strengthening the hypothesis for a potentially causal association.

PMID:33905677 | DOI:10.1016/j.chest.2021.04.035

PLoS One. 2021 Apr 27;16(4):e0250109. doi: 10.1371/journal.pone.0250109. eCollection 2021.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) and lung cancer share common risk factors, epigenetic and genetic alterations, the activation of similar signaling pathways and poor survival. The aim of this study was to examine the gene expression profiles of stromal cells from patients with IPF and lung adenocarcinoma (ADC) as well as from normal lung. The gene expression levels of cultured stromal cells derived from non-smoking patients with ADC from the tumor (n = 4) and the corresponding normal lung (n = 4) as well as from patients with IPF (n = 4) were investigated with Affymetrix microarrays. The expression of collagen type IV alpha 1 chain, periostin as well as matrix metalloproteinase-1 and -3 in stromal cells and lung tissues were examined with quantitative real-time reverse transcriptase polymerase chain reaction and immunohistochemistry, respectively. Twenty genes were similarly up- or down-regulated in IPF and ADC compared to control, while most of the altered genes in IPF and ADC were differently expressed, including several extracellular matrix genes. Collagen type IV alpha 1 chain as well as matrix metalloproteinases-1 and -3 were differentially expressed in IPF compared to ADC. Periostin was up-regulated in both IPF and ADC in comparison to control. All studied factors were localized by immunohistochemistry in stromal cells within fibroblast foci in IPF and stroma of ADC. Despite the similarities found in gene expressions of IPF and ADC, several differences were also detected, suggesting that the molecular changes occurring in these two lung illnesses are somewhat different.

PMID:33905434 | DOI:10.1371/journal.pone.0250109

Respir Res. 2021 Apr 26;22(1):125. doi: 10.1186/s12931-021-01695-y.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) predominantly affects individuals aged > 60 years who have several comorbidities. Nintedanib is an approved treatment for IPF, which reduces the rate of decline in forced vital capacity (FVC). We assessed the efficacy and safety of nintedanib in patients with IPF who were elderly and who had multiple comorbidities.

METHODS: Data were pooled from five clinical trials in which patients were randomised to receive nintedanib 150 mg twice daily or placebo. We assessed outcomes in subgroups by age < 75 versus ≥ 75 years, by < 5 and ≥ 5 comorbidities, and by Charlson Comorbidity Index (CCI) ≤ 3 and > 3 at baseline.

RESULTS: The data set comprised 1690 patients. Nintedanib reduced the rate of decline in FVC (mL/year) over 52 weeks versus placebo in patients aged ≥ 75 years (difference: 105.3 [95% CI 39.3, 171.2]) (n = 326) and < 75 years (difference 125.2 [90.1, 160.4]) (n = 1364) (p = 0.60 for treatment-by-time-by-subgroup interaction), in patients with < 5 comorbidities (difference: 107.9 [95% CI 65.0, 150.9]) (n = 843) and ≥ 5 comorbidities (difference 139.3 [93.8, 184.8]) (n = 847) (p = 0.41 for treatment-by-time-by-subgroup interaction) and in patients with CCI score ≤ 3 (difference: 106.4 [95% CI 70.4, 142.4]) (n = 1330) and CCI score > 3 (difference: 129.5 [57.6, 201.4]) (n = 360) (p = 0.57 for treatment-by-time-by-subgroup interaction). The adverse event profile of nintedanib was generally similar across subgroups. The proportion of patients with adverse events leading to treatment discontinuation was greater in patients aged ≥ 75 years than < 75 years in both the nintedanib (26.4% versus 16.0%) and placebo (12.2% versus 10.8%) groups. Similarly the proportion of patients with adverse events leading to treatment discontinuation was greater in patients with ≥ 5 than < 5 comorbidities (nintedanib: 20.5% versus 15.7%; placebo: 12.1% versus 10.0%).

CONCLUSIONS: Our findings suggest that the effect of nintedanib on reducing the rate of FVC decline is consistent across subgroups based on age and comorbidity burden. Proactive management of adverse events is important to reduce the impact of adverse events and help patients remain on therapy.

TRIAL REGISTRATION: ClinicalTrials.gov NCT00514683, NCT01335464, NCT01335477, NCT02788474, NCT01979952.

PMID:33902584 | DOI:10.1186/s12931-021-01695-y

Respir Res. 2021 Apr 26;22(1):124. doi: 10.1186/s12931-021-01670-7.

ABSTRACT

BACKGROUND: Accurate diagnosis of idiopathic pulmonary fibrosis (IPF) is essential to inform prognosis and treatment. In 2018, the ATS/ERS/JRS/ALAT and Fleischner Society released new diagnostic guidelines for usual interstitial pneumonitis (UIP)/IPF, adding Probable UIP as a CT category based on prior studies demonstrating this category had relatively high positive predictive value (PPV) for histopathologic UIP/Probable UIP. This study applies the 2018 ATS/ERS/JRS/ALAT and Fleischner Society guidelines to determine test characteristics of CT categories in academic clinical practice.

METHODS: CT and histopathology were evaluated by three thoracic radiologists and two thoracic pathologists. Comparison of consensus categorization by the 2018 ATS and Fleischner Society guidelines by CT and histopathology was performed.

RESULTS: Of patients with CT UIP, 87% (PPV, 95% CI: 60-98%) had histopathologic UIP with 97% (CI: 90-100%) specificity. Of patients with CT Probable UIP, 38% (PPV, CI: 14-68%) had histopathologic UIP and 46% (PPV, CI: 19-75%) had either histopathologic UIP or Probable UIP, with 88% (CI: 77-95%) specificity. Patients with CT Indeterminate and Alternative Diagnosis had histopathologic UIP in 27% (PPV, CI: 6-61%) and 21% (PPV, CI: 11-33%) of cases with specificities of 90% (CI: 80-96%) and 25% (CI: 16-37%). Interobserver variability (kappa) between radiologists ranged 0.32-0.81.

CONCLUSIONS: CT UIP and Probable UIP have high specificity for histopathologic UIP, and CT UIP has high PPV for histopathologic UIP. PPV of CT Probable UIP was 46% for combined histopathologic UIP/Probable UIP. Our results indicate that additional studies are needed to further assess and refine the guideline criteria to improve classification performance.

PMID:33902572 | DOI:10.1186/s12931-021-01670-7