The factors that determine fibrosis progression or normal tissue repair are largely unknown. We previously demonstrated that autophagy inhibition-mediated epithelial–mesenchymal transition (EMT) in human alveolar epithelial type II (ATII) cells augments local myofibroblast differentiation in pulmonary fibrosis by paracrine signaling. Here, we report that liver kinase B1 (LKB1) inactivation in ATII cells inhibits autophagy and induces EMT as a consequence. In IPF lungs, this is caused by the down-regulation of CAB39L, a key subunit within the LKB1 complex. 3D co-cultures of ATII cells and MRC5 lung fibroblasts coupled with RNA sequencing (RNA-seq) confirmed that paracrine signaling between LKB1-depleted ATII cells and fibroblasts augmented myofibroblast differentiation. Together, these data suggest that reduced autophagy caused by LKB1 inhibition can induce EMT in ATII cells and contribute to fibrosis via aberrant epithelial–fibroblast crosstalk.

Exercise training is recommended for patients with idiopathic pulmonary fibrosis (IPF); however, the mechanism(s) underlying its physiological benefits remain unclear. We investigated the effects of an individualised aerobic interval training programme on exercise capacity and redox status in IPF patients. IPF patients were recruited prospectively to an 8-week, twice-weekly cardiopulmonary exercise test (CPET)-derived structured responsive exercise training programme (SRETP). Systemic redox status was assessed pre- and post-CPET at baseline and following SRETP completion. An age- and sex-matched non-IPF control cohort was recruited for baseline comparison only. At baseline, IPF patients (n = 15) had evidence of increased oxidative stress compared with the controls as judged by; the plasma reduced/oxidised glutathione ratio (median, control 1856 vs. IPF 736 p = 0.046). Eleven IPF patients completed the SRETP (median adherence 88%). Following SRETP completion, there was a significant improvement in exercise capacity assessed via the constant work-rate endurance time (+82%, p = 0.003). This was accompanied by an improvement in post-exercise redox status (in favour of antioxidants) assessed via serum total free thiols (median increase, +0.26 μmol/g protein p = 0.005) and total glutathione concentration (+0.73 μM p = 0.03), as well as a decrease in post-exercise lipid peroxidation products (−1.20 μM p = 0.02). Following SRETP completion, post-exercise circulating nitrite concentrations were significantly lower compared with baseline (−0.39 μM p = 0.04), suggestive of exercise-induced nitrite utilisation. The SRETP increased both endurance time and systemic antioxidant capacity in IPF patients. The observed reduction in nitrite concentrations provides a mechanistic rationale to investigate nitrite/nitrate supplementation in IPF patients.

Background Computer quantification of baseline computed tomography (CT) radiological pleuroparenchymal fibroelastosis (PPFE) associates with mortality in idiopathic pulmonary fibrosis (IPF). We examined mortality associations of longitudinal change in computer-quantified PPFE-like lesions in IPF and fibrotic hypersensitivity pneumonitis (FHP). Methods Two CT scans 6–36 months apart were retrospectively examined in one IPF (n=414) and one FHP population (n=98). Annualised change in computerised upper-zone pleural surface area comprising radiological PPFE-like lesions (Δ-PPFE) was calculated. Δ-PPFE >1.25% defined progressive PPFE above scan noise. Mixed-effects models evaluated Δ-PPFE against change in visual CT interstitial lung disease (ILD) extent and annualised forced vital capacity (FVC) decline. Multivariable models were adjusted for age, sex, smoking history, baseline emphysema presence, antifibrotic use and diffusion capacity of the lung for carbon monoxide. Mortality analyses further adjusted for baseline presence of clinically important PPFE-like lesions and ILD change. Results Δ-PPFE associated weakly with ILD and FVC change. 22–26% of IPF and FHP cohorts demonstrated progressive PPFE-like lesions which independently associated with mortality in the IPF cohort (hazard ratio 1.25, 95% CI 1.16–1.34, p<0.0001) and the FHP cohort (hazard ratio 1.16, 95% CI 1.00–1.35, p=0.045). Interpretation Progression of PPFE-like lesions independently associates with mortality in IPF and FHP but does not associate strongly with measures of fibrosis progression.

Extracellular matrix (ECM) stiffening with downstream activation of mechanosensitive pathways is strongly implicated in fibrosis. We previously reported that altered collagen nanoarchitecture is a key determinant of pathogenetic ECM structure-function in human fibrosis (Jones et al., 2018). Here, through human tissue, bioinformatic and ex vivo studies we provide evidence that hypoxia-inducible factor (HIF) pathway activation is a critical pathway for this process regardless of the oxygen status (pseudohypoxia). Whilst TGFβ increased the rate of fibrillar collagen synthesis, HIF pathway activation was required to dysregulate post-translational modification of fibrillar collagen, promoting pyridinoline cross-linking, altering collagen nanostructure, and increasing tissue stiffness. In vitro, knockdown of Factor Inhibiting HIF (FIH), which modulates HIF activity, or oxidative stress caused pseudohypoxic HIF activation in the normal fibroblasts. By contrast, endogenous FIH activity was reduced in fibroblasts from patients with lung fibrosis in association with significantly increased normoxic HIF pathway activation. In human lung fibrosis tissue, HIF-mediated signalling was increased at sites of active fibrogenesis whilst subpopulations of human lung fibrosis mesenchymal cells had increases in both HIF and oxidative stress scores. Our data demonstrate that oxidative stress can drive pseudohypoxic HIF pathway activation which is a critical regulator of pathogenetic collagen structure-function in fibrosis.

Background Routine follow-up of patients hospitalised with COVID-19 is recommended, however due to the ongoing high number of infections this is not without significant health resource and economic burden. In a previous study we investigated the prevalence of, and risk factors for, persistent chest radiograph (CXR) abnormalities post-hospitalisation with COVID-19 and identified a 5-point composite score that strongly predicted risk of persistent CXR abnormality at 12-weeks. Here we sought to validate and refine our findings in an independent cohort of patients. Methodology A single-centre prospective study of consecutive patients attending a virtual post-hospitalisation COVID-19 clinic and CXR as part of their standard clinical care between 2nd March – 22nd June 2021. Inpatient and follow-up CXRs were scored by the assessing clinician for extent of pulmonary infiltrates (0–4 in each lung) with complete resolution defined as a follow-up score of zero. Results 182 consecutive patients were identified of which 31% had persistent CXR abnormality at 12-weeks. Patients with persistent CXR abnormality were significantly older (p < 0.001), had a longer hospital length of stay (p = 0.005), and had a higher incidence of both level 2 or 3 facility admission (level 2/3 care) (p = 0.003) and ever-smoking history (p = 0.038). Testing our composite score in the present cohort we found it predicted persistent CXR abnormality with reasonable accuracy (area under the receiver operator curve [AUROC 0.64]). Refining this score replacing obesity with Age ≥ 50 years, we identify the SHADE-750 score (1-point each for; Smoking history, Higher-level care (level 2/3 admission), Age ≥ 50 years, Duration of admission ≥ 15 days and Enzyme-lactate dehydrogenase (LDH ≥ 750U/L), that accurately predicted risk of persistent CXR abnormality, both in the present cohort (AUROC 0.73) and when retrospectively applied to our 1st cohort (AUROC 0.79). Applied to both cohorts combined (n = 213) it again performed strongly (AUROC 0.75) with all patients with a score of zero (n = 18) having complete CXR resolution at 12-weeks. Conclusions In two independent cohorts of patients hospitalised with COVID-19, we identify a 5-point score which accurately predicts patients at risk of persistent CXR abnormality at 12-weeks. This tool could be used by clinicians to identify patients in which radiological follow-up may not be required.

Imaging biomarkers derived from medical images play an important role in diagnosis, prognosis, and therapy response assessment. Developing prognostic imaging biomarkers which can achieve reliable survival prediction is essential for prognostication across various diseases and imaging modalities. In this work, we propose a method for discovering patch-level imaging patterns which we then use to predict mortality risk and identify prognostic biomarkers. Specifically, a contrastive learning model is first trained on patches to learn patch representations, followed by a clustering method to group similar underlying imaging patterns. The entire medical image can be thus represented by a long sequence of patch representations and their cluster assignments. Then a memory-efficient clustering Vision Transformer is proposed to aggregate all the patches to predict mortality risk of patients and identify high-risk patterns. To demonstrate the effectiveness and generalizability of our model, we test the survival prediction performance of our method on two sets of patients with idiopathic pulmonary fibrosis (IPF), a chronic, progressive, and life-threatening interstitial pneumonia of unknown etiology. Moreover, by comparing the high-risk imaging patterns extracted by our model with existing imaging patterns utilised in clinical practice, we can identify a novel biomarker that may help clinicians improve risk stratification of IPF patients.

In two separate cohorts of patients with idiopathic pulmonary fibrosis, mediastinal adenopathy was common and an increase in the size of lymphadenopathy independently predicts mortalityhttps://bit.ly/32vEMnX

Idiopathic pulmonary fibrosis (IPF) is the prototypic progressive fibrotic lung disease with a median survival of 2 to 4 years. Injury to and/or dysfunction of the alveolar epithelium is strongly implicated in IPF disease initiation, but the factors that determine whether fibrosis progresses rather than normal tissue repair occurs remain poorly understood. We previously demonstrated that zinc finger E-box-binding homeobox 1-mediated epithelial-mesenchymal transition in human alveolar epithelial type II (ATII) cells augments transforming growth factor-β-induced profibrogenic responses in underlying lung fibroblasts via paracrine signaling. Here, we investigated bidirectional epithelial-mesenchymal crosstalk and its potential to drive fibrosis progression. RNA-Seq of lung fibroblasts exposed to conditioned media from ATII cells undergoing RAS-induced epithelial-mesenchymal transition identified many differentially expressed genes including those involved in cell migration and extracellular matrix regulation. We confirmed that paracrine signaling between RAS-activated ATII cells and fibroblasts augmented fibroblast recruitment and demonstrated that this involved a zinc finger E-box-binding homeobox 1-tissue plasminogen activator axis. In a reciprocal fashion, paracrine signaling from transforming growth factor-β-activated lung fibroblasts or IPF fibroblasts induced RAS activation in ATII cells, at least partially through the secreted protein acidic and rich in cysteine, which may signal via the epithelial growth factor receptor via epithelial growth factor-like repeats. Together, these data identify that aberrant bidirectional epithelial-mesenchymal crosstalk in IPF drives a chronic feedback loop that maintains a wound-healing phenotype and provides self-sustaining profibrotic signals.

Redox dysregulation and oxidative stress have been implicated in asthma pathogenesis. Exercise interventions improve symptoms and reduce inflammation in asthma patients, but the underlying mechanisms remain unclear. We hypothesized that a personalised exercise intervention would improve asthma control by reducing lung inflammation through modulation of local and systemic reactive species interactions, thereby increasing antioxidant capacity. We combined deep redox metabolomic profiling with clinical assessment in an exploratory cohort of six female patients with symptomatic asthma and studied their responses to a metabolically targeted exercise intervention over 12 weeks. Plasma antioxidant capacity and circulating nitrite levels increased following the intervention (p = 0.028) and lowered the ratio of reduced to oxidised glutathione (p = 0.029); this was accompanied by improvements in physical fitness (p = 0.046), symptoms scores (p = 0.020), quality of life (p = 0.046), lung function (p = 0.028), airway hyperreactivity (p = 0.043), and eosinophilic inflammation (p = 0.007). Increased physical fitness correlated with improved plasma antioxidant capacity (p = 0.019), peak oxygen uptake and nitrite changes (p = 0.005), the latter also associated with reductions in peripheral blood eosinophil counts (p = 0.038). Thus, increases in "redox resilience" may underpin the clinical benefits of exercise in asthma. An improved understanding of exercise-induced alterations in redox regulation offers opportunities for greater treatment personalisation and identification of new treatment targets.

AbstractWhile Idiopathic pulmonary fibrosis (IPF) remains the exemplar progressive fibrotic lung disease, there remains a cohort of non-IPF fibrotic lung diseases (fILD) which adopt a similar clinical behaviour to IPF despite therap. This phenotypically related group of conditions, where progression of disease is similar to that seen in IPF, have recently been described as Progressive Fibrotic Interstitial Lung diseases (PF-ILD). Previous estimates suggest that between 18 to 40% of all fILD will develop progressive disease, however, the exact burden remains unknown. This retrospective, observational study therefore aimed to estimate the incidence of PF-ILD across England.All new referrals seen across nine UK centres for their first outpatient clinic appointment between 1st August 2017 and 31st January 2018 were assessed against the diagnostic criteria for PF-ILD laid out in the INBUILD trial. A total of 1749 patients with fILD were assessed. In this cohort of patients at risk of developing PF-ILD the INBUILD criteria were met in 14.5% (253/1749) of all new non-IPF fILD referrals. The average time from referral to specialist centre to diagnosis of progressive phenotype was 311 days. Of the progression events the majority were driven by a measured drop in FVC, with more than half of patients experiencing a drop of 10%. Almost one quarter of patients (24.1%) were diagnosed with progressive disease on the basis of radiological and symptomatic progression alone without a spirometric deterioration.This study represents a fair and balanced approach to assessing the incidence of objectively measurable and treatable PF-ILDs in the UK. A rate of 14.5% of new referrals with non-IPF ILD is less than that reported in previous studies however our methodology is likely to give a more accurate result than estimates based on extrapolation from general disease statistics, from physician-reported estimates prone to significant biases, or insurance claim processes also substantially prone to bias. This information has implication for workforce planning and the funding of anti-fibrotic therapy in the UK and beyond.

Introduction: Exercise training is recommended for IPF patients but the optimum program and the mechanisms underlying improvements in exercise capacity are unknown. We tested feasibility of a HIIT in IPF. Methods: A single-centre study of IPF patients. An 8-week twice-weekly cycle-ergometer based HIIT was personalised using participants volume of oxygen consumption at anaerobic threshold (VO2AT) and peak (VO2peak) assessed by incremental CPET. Primary outcome was endurance time on constant load test at 75% VO2peak. Ethical approval obtained (REC 17/SC/0342). Results: Interim analysis of 11 patients. Baseline demographics as follows; males 82% with mean (SD) age 73.5years (6.8), FVC% 76.5 (13.4) and DLCO% 50.1 (15.8). Participants had significantly impaired exercise capacity at baseline with mean (SD) VO2peak of 12.3ml/kg/min (3.3) and VO2AT 8.3ml/kg/min (1.3). Participants had good adherence to HITT with mean of 15/16 sessions attended with no serious adverse events. HITT led to clinically meaningful improvement in mean endurance time [pre 8.3min vs post 16.8min difference 8.5min (95%CI 4.2-12.8) p<0.01] and 6min walk [pre 374m vs post 409m difference 35m (95%CI 0.6-69.4) p<0.05]. Significant increase was also observed in mean peak minute ventilation (peakVE) [pre 60.2L/min vs post 69.3L/min p=0.02]. However no change was observed in either VO2peak or VO2AT following HITT. Conclusion: A CPET derived HIIT was feasible in this cohort of IPF patients and led to significant improvement in endurance time and 6min walk. Increased peakVE following HITT suggests improved ventilatory mechanics may in part account for increased exercise test performance.

Introduction: A proportion of patients with ILD remain unclassified after multidisciplinary discussion (MDD). Without a definitive diagnosis there is currently a lack of licensed treatment options for this group. We aimed to review outcomes in this cohort of patients. Method: UK single centre retrospective review of all patients with unclassified ILD diagnosis following ILD MDD between 12/11/2012 and 19/6/2017 with a minimum 2 year follow up. Data extracted from electronic records. Ethical approval obtained. Results: 145 patients included with a mean (SD) follow-up period of 3.9 years (1.2). Baseline demographics were as follows: males 62.1% with mean (SD); age 70.7 years (9.2), FVC% 81.4 (21.4) and DLCO% 55.4 (17.1). At censor, 40.7% of patients had been reclassified to an alternative diagnosis. The median time taken to re-classify patients was 90 days with a wide range (16-2052 days). Common review diagnosis were (n); idiopathic pulmonary fibrosis (29), hypersensitivity pneumonitis (10) and connective tissue disease related ILD (3). Repeat CT and MDD re-discussion led to re-classification in 23% of patients. 15% of patients had a surgical lung biopsy and this led to subsequent re-classification of ILD in 82% of people biopsied. In patients with serial FVC% (n=101), 25% had a >10% decline over a mean interval of 2.5 years. 40% of patients with >10% FVC decline remained unclassified. No baseline characteristics were found to predict progression. Conclusion: These results highlight the importance of MDD follow up of patients with unclassified ILD over time to both review diagnosis and monitor for disease progression to enable appropriate disease targeted therapy.

Rationale: The impact of coronavirus disease (COVID-19) on patients with interstitial lung disease (ILD) has not been established. Objectives: To assess outcomes in patients with ILD hospitalized for COVID-19 versus those without ILD in a contemporaneous age-, sex-, and comorbidity-matched population. Methods: An international multicenter audit of patients with a prior diagnosis of ILD admitted to the hospital with COVID-19 between March 1 and May 1, 2020, was undertaken and compared with patients without ILD, obtained from the ISARIC4C (International Severe Acute Respiratory and Emerging Infection Consortium Coronavirus Clinical Characterisation Consortium) cohort, admitted with COVID-19 over the same period. The primary outcome was survival. Secondary analysis distinguished idiopathic pulmonary fibrosis from non-idiopathic pulmonary fibrosis ILD and used lung function to determine the greatest risks of death. Measurements and Main Results: Data from 349 patients with ILD across Europe were included, of whom 161 were admitted to the hospital with laboratory or clinical evidence of COVID-19 and eligible for propensity score matching. Overall mortality was 49% (79/161) in patients with ILD with COVID-19. After matching, patients with ILD with COVID-19 had significantly poorer survival (hazard ratio [HR], 1.60; confidence interval, 1.17-2.18; P = 0.003) than age-, sex-, and comorbidity-matched controls without ILD. Patients with an FVC of <80% had an increased risk of death versus patients with FVC >= 80% (HR, 1.72; 1.05-2.83). Furthermore, obese patients with ILD had an elevated risk of death (HR, 2.27; 1.39-3.71). Conclusions: Patients with ILD are at increased risk of death from COVID-19, particularly those with poor lung function and obesity. Stringent precautions should be taken to avoid COVID-19 in patients with ILD.

Introduction: We have found that bronchoalveolar lavage recovery is significantly reduced in severe asthma, with group mean BAL recovery in severe asthma (n= 67, 36.4%) being less than that in health (n=65, 51.2%, p<.005) and mild steroid-naïve asthma (n=87, 52.0%, p<.001). We have thus prospectively investigated the relationship between spirometric and oscillometric measures of lung function and BAL recovery in severe asthma. Method: Patients (n=23) within the WATCH Difficult Asthma Cohort had measures of post-bronchodilator forced oscillometry and spirometry prior to bronchoscopy with BAL. All bronchoscopies used 120mL BAL, introduced in 20mL aliquots, followed after a 10s dwell time by gentle suction. The data is presented as mean ±SD for normally distributed and median [IQR] for non-normally distributed. The results were analysed using Spearman’s correlation, with significance of p<.05. Results: This cohort was 52% male, with a mean age of 58.2 years ±12.9, and impaired spirometry (FEV1 81.6% pred ±17.2, FEV1/FVC 69.5% ±12.8, FVC 94.5% pred ±18.5, MEF25-75 64.9% pred ±34.7) and oscillometry (R5 109.4% pred [66.69-152.11], Fres 131.5% pred [81.7-181.3], AX 213.2% pred [-67.8-494.2], R5-20 z-score 0.9 [-0.65-2.45]). BAL return (35.6mL [±19.6]) was very strongly correlated with FEV1/FVC ratio (r=.761, p<.001) and MEF25-75 (r=.740, p<.001), and strongly correlated with R5% pred (r=-.518, p.011), Fres% pred (r=-.474, p.022), AX% pred (r=-.422, p.045) and R5-20 z-score (r=-.568, p.005). Conclusions: In severe asthma BAL return correlates with lung function and our findings suggest that return is related not only to airflow obstruction but also to diminished elastic recoil affecting peripheral airways.

For patients with IPF, length of time in healthcare systems prior to review in an ILD clinic reflects disease severity and may impact upon patient outcome https://bit.ly/2TkO26r.

Background: Anti-fibrotic therapies have transformed the care of patients with Idiopathic Pulmonary Fibrosis (IPF). Within the United Kingdom, prescribing criteria set by NICE (National Institute for Health and Care Excellence) restrict anti-fibrotic prescription to patients with an FVC of 50-80% predicted, potentially excluding a significant proportion of patients with IPF from receiving anti-fibrotic treatment. Aims and Objectives: To investigate the proportion of patients with IPF that do not meet UK NICE prescribing criteria for anti-fibrotic treatment. Methods: This is a retrospective specialist centre cohort study. Consecutive patients with an MDT diagnosis of IPF and a minimum of 12 months follow up were included in the analysis. Results: 194 patients with IPF were identified. 150 (77%) were male and 120 (62%) were ex-smokers. Mean age at diagnosis was 73 years (SD=8 years). The most common comorbidity was GORD (n=73, 38%) while 36 (19%) had a background of ischaemic heart disease. At diagnosis mean FVC was 75% predicted (SD=20%) and mean TLCO was 47% predicted (SD=16%). 150 patients (77%) were eligible for anti-fibrotic treatment on diagnosis. 29 (15%) patients were not eligible for anti-fibrotics when assessed by NICE criteria, with 20 having an FVC>80% predicted while 9 had an FVC<50% predicted. To date, 5 of the 20 patients with an FVC>80% have subsequently received anti-fibrotic treatment following FVC decline. Conclusions: 15% of patients with IPF referred for specialist centre care were ineligible for anti-fibrotic treatment as a consequence of the NICE FVC prescribing criteria.

Introduction: Exercise intervention may modulate the inflammatory basis for asthma, offering clinical benefit beyond functional improvement. Interval training is tolerated in asthmatics, and may improve symptom control. Aims and Objectives: This proof of concept study has recruited poorly controlled asthmatics to a 12-week Interval Training Programme to ascertain if it is feasible and safe, improves symptom control, airway and systemic inflammation, and physical fitness. Methods: Participants were sampled at baseline and 3, 6 and 12 weeks of training. Results: Early results (n=7) suggest safety and tolerability, with improvement between baseline and week 3. Wilcoxon signed rank showed that Asthma Control Questionnaire score improved significantly (mdn=2 [IQR=1.8,2.3] vs mdn=1.63 [IQR=1.37,1.96], p=0.028). Asthma Quality of Life Questionnaire score improved significantly (mdn=4.97 [IQR=4.46,5.3] vs median 5.5 [IQR=5.09,5.84] p=0.018), but was not associated with improved physical fitness, assessed by VO2 at anaerobic threshold (mdn=10.1 [IQR=9.25,11.35] vs 9.7ml/kg/min [IQR=8.6,14]; p=0.46) and VO2peak (mdn= 21.30 [IQR=12.80,25.40] vs 22.8ml/kg/min [IQR=13.80,28.80]; p=0.86). There were no statistically significant improvements in FeNO (median=37.75 [IQR=27.63,66] vs median=36 [IQR=20,82], p=0.39) or peripheral blood eosinophilia (mdn=0.2 [IQR=0.2,0.38] vs mdn=0.3 [IQR=0.2,0.4], p=0.57). Conclusion: These interim data suggests even a short exercise intervention in poorly controlled asthma is tolerated and beneficial for symptom control, which may precede improvement in markers of inflammation. Prescribed training programmes may provide a cost-effective treatment adjunct in poorly controlled asthma.