COVID-19 and pulmonary fibrosis: A potential role for lung epithelial cells and fibroblasts.

The COVID-19 pandemic rapidly spread around the world following the first reports in Wuhan City, China in late 2019. The disease, caused by the novel SARS-CoV-2 virus, is primarily a respiratory condition that can affect numerous other bodily systems including the cardiovascular and gastrointestinal systems. The disease ranges in severity from asymptomatic through to severe acute respiratory distress requiring intensive care treatment and mechanical ventilation, which can lead to respiratory failure and death. It has rapidly become evident that COVID-19 patients can develop features of interstitial pulmonary fibrosis, which in many cases persist for as long as we have thus far been able to follow the patients. Many questions remain about how such fibrotic changes occur within the lung of COVID-19 patients, whether the changes will persist long term or are capable of resolving, and whether post-COVID-19 pulmonary fibrosis has the potential to become progressive, as in other fibrotic lung diseases. This review brings together our existing knowledge on both COVID-19 and pulmonary fibrosis, with a particular focus on lung epithelial cells and fibroblasts, in order to discuss common pathways and processes that may be implicated as we try to answer these important questions in the months and years to come.

Rheumatoid arthritis and idiopathic pulmonary fibrosis: a bidirectional Mendelian randomisation study.

BACKGROUND: A usual interstitial pneumonia (UIP) pattern of lung injury is a key feature of idiopathic pulmonary fibrosis (IPF) and is also observed in up to 40% of individuals with rheumatoid arthritis (RA)-associated interstitial lung disease (RA-ILD). The RA-UIP phenotype could result from either a causal relationship of RA on UIP or vice versa, or from a simple co-occurrence of RA and IPF due to shared demographic, genetic or environmental risk factors. METHODS: We used two-sample bidirectional Mendelian randomisation (MR) to test the hypothesis of a causal effect of RA on UIP and of UIP on RA, using variants from genome-wide association studies (GWAS) of RA (separately for seropositive (18 019 cases and 991 604 controls) and seronegative (8515 cases and 1 015 471 controls) RA) and of IPF (4125 cases and 20 464 controls) as genetic instruments. Sensitivity analyses were conducted to assess the robustness of the results to violations of the MR assumptions. FINDINGS: IPF showed a significant causal effect on seropositive RA, with developing IPF increasing the risk of seropositive RA (OR=1.06, 95% CI: 1.04 to 1.08, p<0.001) which was robust under all models. For the MR in the other direction, seropositive RA showed a significant protective effect on IPF (OR=0.93; 95% CI: 0.87 to 0.99; p=0.032), but the effect was not significant when sensitivity analyses were applied. This was likely because of bias due to exclusion of patients with RA from among the cases in the IPF GWAS, or possibly because our genetic instruments did not fully capture the effect of the complex human leucocyte antigen region, the strongest RA genetic risk factor. INTERPRETATION: Our findings support the hypothesis that RA-UIP may be due to a cause-effect relationship between UIP and RA, rather than due to a coincidental occurrence of IPF in patients with RA. The significant causal effect of IPF on seropositive RA suggests that pathomechanisms involved in the development of UIP may promote RA, and this may help inform future guidelines on screening for ILD in patients with RA.

Adaptive multi-interventional trial platform to improve patient care for fibrotic interstitial lung diseases.

BACKGROUND: Fibrotic interstitial lung diseases (fILDs) are a heterogeneous group of lung diseases associated with significant morbidity and mortality. Despite a large increase in the number of clinical trials in the last 10 years, current regulatory-approved management approaches are limited to two therapies that prevent the progression of fibrosis. The drug development pipeline is long and there is an urgent need to accelerate this process. This manuscript introduces the concept and design of an innovative research approach to drug development in fILD: a global Randomised Embedded Multifactorial Adaptive Platform in fILD (REMAP-ILD). METHODS: Description of the REMAP-ILD concept and design: the specific terminology, design characteristics (multifactorial, adaptive features, statistical approach), target population, interventions, outcomes, mission and values, and organisational structure. RESULTS: The target population will be adult patients with fILD, and the primary outcome will be a disease progression model incorporating forced vital capacity and mortality over 12 months. Responsive adaptive randomisation, prespecified thresholds for success and futility will be used to assess the effectiveness and safety of interventions. REMAP-ILD embraces the core values of diversity, equity, and inclusion for patients and researchers, and prioritises an open-science approach to data sharing and dissemination of results. CONCLUSION: By using an innovative and efficient adaptive multi-interventional trial platform design, we aim to accelerate and improve care for patients with fILD. Through worldwide collaboration, novel analytical methodology and pragmatic trial delivery, REMAP-ILD aims to overcome major limitations associated with conventional randomised controlled trial approaches to rapidly improve the care of people living with fILD.

Feasibility and acceptability of remotely monitoring spirometry and pulse oximetry as part of interstitial lung disease clinical care: a single arm observational study.

BACKGROUND: Remote monitoring of patient-recorded spirometry and pulse oximetry offers an alternative approach to traditional hospital-based monitoring of interstitial lung disease (ILD). Remote spirometry has been observed to reasonably reflect clinic spirometry in participants with ILD but remote monitoring has not been widely incorporated into clinical practice. We assessed the feasibility of remotely monitoring patients within a clinical ILD service. METHODS: Prospective, single-arm, open-label observational multi-centre study (NCT04850521). Inclusion criteria included ILD diagnosis, age ≥ 18 years, FVC ≥ 50% predicted. 60 participants were asked to record a single spirometry and oximetry measurement at least once daily, monitored weekly by their local clinical team. Feasibility was defined as ≥ 68% of participants with ≥ 70% adherence to study measurements and recording measurements ≥ 3 times/week throughout. RESULTS: A total of 60 participants were included in the analysis. 42/60 (70%) were male; mean age 67.8 years (± 11.2); 34/60 (56.7%) had idiopathic pulmonary fibrosis (IPF), Median ILD-GAP score was 3 (IQR 1-4.75). Spirometry adherence was achieved for ≥ 70% of study days in 46/60 participants (77%) and pulse oximetry adherence in 50/60 participants (83%). Recording ≥ 3 times/week every week was provided for spirometry in 41/60 participants (68%) and pulse oximetry in 43/60 participants (72%). Mean difference between recent clinic and baseline home spirometry was 0.31 L (± 0.72). 85.7% (IQR 63.9-92.6%) home spirometry attempts/patient were acceptable or usable according to ERS/ATS spirometry criteria. Positive correlation was observed between ILD-GAP score and adherence to spirometry and oximetry (rho 0.24 and 0.38 respectively). Adherence of weekly monitoring by clinical teams was 80.95% (IQR 64.19-95.79). All participants who responded to an experience questionnaire (n = 33) found remote measurements easy to perform and 75% wished to continue monitoring their spirometry at the conclusion of the study. CONCLUSION: Feasibility of remote monitoring within an ILD clinical service was demonstrated over 3 months for both daily home spirometry and pulse oximetry of patients. Remote monitoring may be more acceptable to participants who are older or have more advanced disease. TRIAL REGISTRATION: clinicaltrials.gov NCT04850521 registered 20th April 2021.

Combination of BAL and Computed Tomography Differentiates Progressive and Non-progressive Fibrotic Lung Diseases.

Rationale: Identifying patients with pulmonary fibrosis (PF) at risk of progression can guide management. Objectives: To explore the utility of combining baseline BAL and computed tomography (CT) in differentiating progressive and nonprogressive PF. Methods: The derivation cohort consisted of incident cases of PF for which BAL was performed as part of a diagnostic workup. A validation cohort was prospectively recruited with identical inclusion criteria. Baseline thoracic CT scans were scored for the extent of fibrosis and usual interstitial pneumonia (UIP) pattern. The BAL lymphocyte proportion was recorded. Annualized FVC decrease of >10% or death within 1 year was used to define disease progression. Multivariable logistic regression identified the determinants of the outcome. The optimum binary thresholds (maximal Wilcoxon rank statistic) at which the extent of fibrosis on CT and the BAL lymphocyte proportion could distinguish disease progression were identified. Measurements and Main Results: BAL lymphocyte proportion, UIP pattern, and fibrosis extent were significantly and independently associated with disease progression in the derivation cohort (n = 240). Binary thresholds for increased BAL lymphocyte proportion and extensive fibrosis were identified as 25% and 20%, respectively. An increased BAL lymphocyte proportion was rare in patients with a UIP pattern (8 of 135; 5.9%) or with extensive fibrosis (7 of 144; 4.9%). In the validation cohort (n = 290), an increased BAL lymphocyte proportion was associated with a significantly lower probability of disease progression in patients with nonextensive fibrosis or a non-UIP pattern. Conclusions: BAL lymphocytosis is rare in patients with extensive fibrosis or a UIP pattern on CT. In patients without a UIP pattern or with limited fibrosis, a BAL lymphocyte proportion of ⩾25% was associated with a lower likelihood of progression.

Complex roles of TGF-ß signaling pathways in lung development and bronchopulmonary dysplasia.

As survival of extremely preterm infants continues to improve, there is also an associated increase in bronchopulmonary dysplasia (BPD), one of the most significant complications of preterm birth. BPD development is multifactorial resulting from exposure to multiple antenatal and postnatal stressors. BPD has both short-term health implications and long-term sequelae including increased respiratory, cardiovascular, and neurological morbidity. Transforming growth factor ß (TGF-ß) is an important signaling pathway in lung development, organ injury, and fibrosis and is implicated in the development of BPD. This review provides a detailed account on the role of TGF-ß in antenatal and postnatal lung development, the effect of known risk factors for BPD on the TGF-ß signaling pathway, and how medications currently in use or under development, for the prevention or treatment of BPD, affect TGF-ß signaling.

Parenchymal lung abnormalities following hospitalisation for COVID-19 and viral pneumonitis: a systematic review and meta-analysis.

INTRODUCTION: Persisting respiratory symptoms in COVID-19 survivors may be related to development of pulmonary fibrosis. We assessed the proportion of chest CT scans and pulmonary function tests consistent with parenchymal lung disease in the follow-up of people hospitalised with COVID-19 and viral pneumonitis. METHODS: Systematic review and random effects meta-analysis of proportions using studies of adults hospitalised with SARS-CoV-2, SARS-CoV, MERS-CoV or influenza pneumonia and followed up within 12 months. Searches performed in MEDLINE and Embase. Primary outcomes were proportion of radiological sequelae on CT scans; restrictive impairment; impaired gas transfer. Heterogeneity was explored in meta-regression. RESULTS: Ninety-five studies (98.9% observational) were included in qualitative synthesis, 70 were suitable for meta-analysis including 60 SARS-CoV-2 studies with a median follow-up of 3 months. In SARS-CoV-2, the overall estimated proportion of inflammatory sequelae was 50% during follow-up (0.50; 95% CI 0.41 to 0.58; I2=95%), fibrotic sequelae were estimated in 29% (0.29; 95% CI 0.22 to 0.37; I2=94.1%). Follow-up time was significantly associated with estimates of inflammatory sequelae (-0.036; 95% CI -0.068 to -0.004; p=0.029), associations with fibrotic sequelae did not reach significance (-0.021; 95% CI -0.051 to 0.009; p=0.176). Impaired gas transfer was estimated at 38% of lung function tests (0.38 95% CI 0.32 to 0.44; I2=92.1%), which was greater than restrictive impairment (0.17; 95% CI 0.13 to 0.23; I2=92.5%), neither were associated with follow-up time (p=0.207; p=0.864). DISCUSSION: Sequelae consistent with parenchymal lung disease were observed following COVID-19 and other viral pneumonitis. Estimates should be interpreted with caution due to high heterogeneity, differences in study casemix and initial severity. PROSPERO REGISTRATION NUMBER: CRD42020183139.

Phosphodiesterase 5 inhibitor treatment and survival in interstitial lung disease pulmonary hypertension: A Bayesian retrospective observational cohort study.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension is a life-limiting complication of interstitial lung disease (ILD-PH). We investigated whether treatment with phosphodiesterase 5 inhibitors (PDE5i) in patients with ILD-PH was associated with improved survival. METHODS: Consecutive incident patients with ILD-PH and right heart catheterisation, echocardiography and spirometry data were followed from diagnosis to death, transplantation or censoring with all follow-up and survival data modelled by Bayesian methods. RESULTS: The diagnoses in 128 patients were idiopathic pulmonary fibrosis (n = 74, 58%), hypersensitivity pneumonitis (n = 17, 13%), non-specific interstitial pneumonia (n = 12, 9%), undifferentiated ILD (n = 8, 6%) and other lung diseases (n = 17, 13%). Final outcomes were death (n = 106, 83%), transplantation (n = 9, 7%) and censoring (n = 13, 10%). Patients treated with PDE5i (n = 50, 39%) had higher mean pulmonary artery pressure (median 38 mm Hg [interquartile range, IQR: 34, 43] vs. 35 mm Hg [IQR: 31, 38], p = 0.07) and percentage predicted forced vital capacity (FVC; median 57% [IQR: 51, 73] vs. 52% [IQR: 45, 66], p=0.08) though differences did not reach significance. Patients treated with PDE5i survived longer than untreated patients (median 2.18 years [95% CI: 1.43, 3.04] vs. 0.94 years [0.69, 1.51], p = 0.003) independent of all other prognostic markers by Bayesian joint-modelling (HR 0.39, 95% CI: 0.23, 0.59, p < 0.001) and propensity-matched analyses (HR 0.38, 95% CI: 0.22, 0.58, p < 0.001). Survival difference with treatment was significantly larger if right ventricular function was normal, rather than abnormal, at presentation (+2.55 years, 95% CI: -0.03, +3.97 vs. +0.98 years, 95% CI: +0.47, +2.00, p = 0.04). CONCLUSION: PDE5i treatment in ILD-PH should be investigated by a prospective randomized trial.

Lysyl oxidase like 2 is increased in asthma and contributes to asthmatic airway remodelling.

BACKGROUND: Airway smooth muscle (ASM) cells are fundamental to asthma pathogenesis, influencing bronchoconstriction, airway hyperresponsiveness and airway remodelling. The extracellular matrix (ECM) can influence tissue remodelling pathways; however, to date no study has investigated the effect of ASM ECM stiffness and cross-linking on the development of asthmatic airway remodelling. We hypothesised that transforming growth factor-ß (TGF-ß) activation by ASM cells is influenced by ECM in asthma and sought to investigate the mechanisms involved. METHODS: This study combines in vitro and in vivo approaches: human ASM cells were used in vitro to investigate basal TGF-ß activation and expression of ECM cross-linking enzymes. Human bronchial biopsies from asthmatic and nonasthmatic donors were used to confirm lysyl oxidase like 2 (LOXL2) expression in ASM. A chronic ovalbumin (OVA) model of asthma was used to study the effect of LOXL2 inhibition on airway remodelling. RESULTS: We found that asthmatic ASM cells activated more TGF-ß basally than nonasthmatic controls and that diseased cell-derived ECM influences levels of TGF-ß activated. Our data demonstrate that the ECM cross-linking enzyme LOXL2 is increased in asthmatic ASM cells and in bronchial biopsies. Crucially, we show that LOXL2 inhibition reduces ECM stiffness and TGF-ß activation in vitro, and can reduce subepithelial collagen deposition and ASM thickness, two features of airway remodelling, in an OVA mouse model of asthma. CONCLUSION: These data are the first to highlight a role for LOXL2 in the development of asthmatic airway remodelling and suggest that LOXL2 inhibition warrants further investigation as a potential therapy to reduce remodelling of the airways in severe asthma.

Short-term lung function changes predict mortality in patients with fibrotic hypersensitivity pneumonitis.

BACKGROUND AND OBJECTIVE: A proportion of patients with fibrotic hypersensitivity pneumonitis (fHP) follow a progressive disease course despite immunosuppressive treatment. Little is known about predictors of mortality in fHP. We aimed to investigate the impact of short-term lung function changes in fHP on mortality. METHODS: Baseline demographics for 145 consecutive patients with a multi-disciplinary team diagnosis of fHP, as well as baseline and 1-year follow-up of lung function, baseline echocardiographic findings, bronchoalveolar lavage (BAL) cellularity and all-cause mortality were recorded. Changes in forced vital capacity (FVC) ≥ 5% and ≥10%, and diffusion capacity of the lung for carbon monoxide (DLCO) ≥ 10% and ≥15% at 1 year were calculated. Cox proportional hazards analysis was performed to test for associations with mortality. RESULTS: Baseline lung function severity, age, presence of honeycombing on computed tomography (CT) and echocardiographic pulmonary arterial systolic pressure (PASP) ≥ 40 mm Hg were associated with early mortality, while BAL lymphocytosis was associated with improved survival. A decline in FVC ≥ 5% (hazard ratio [HR]: 3.10, 95% CI: 2.00-4.81, p < 0.001), FVC ≥ 10% (HR: 3.11, 95% CI: 1.94-4.99, p < 0.001), DLCO ≥ 10% (HR: 2.80, 95% CI: 1.78-4.42, p < 0.001) and DLCO ≥ 15% (HR: 2.92, 95% CI: 1.18-4.72, p < 0.001) at 1 year was associated with markedly reduced survival on univariable and multivariable analyses after correcting for demographic variables, disease severity, honeycombing on CT and treatment, as well as BAL lymphocytosis and PASP ≥ 40 mm Hg on echocardiography, in separate models. CONCLUSION: Worsening in FVC and DLCO at 1 year, including a marginal decline in FVC ≥ 5% and DLCO ≥ 10%, is predictive of markedly reduced survival in fHP.

Systematic review and meta-analysis of anakinra, sarilumab, siltuximab and tocilizumab for COVID-19.

BACKGROUND: There is accumulating evidence for an overly activated immune response in severe COVID-19, with several studies exploring the therapeutic role of immunomodulation. Through systematic review and meta-analysis, we assess the effectiveness of specific interleukin inhibitors for the treatment of COVID-19. METHODS: Electronic databases were searched on 7 January 2021 to identify studies of immunomodulatory agents (anakinra, sarilumab, siltuximab and tocilizumab) for the treatment of COVID-19. The primary outcomes were severity on an Ordinal Scale measured at day 15 from intervention and days to hospital discharge. Key secondary endpoints included overall mortality. RESULTS: 71 studies totalling 22 058 patients were included, 6 were randomised trials. Most studies explored outcomes in patients who received tocilizumab (60/71). In prospective studies, tocilizumab was associated with improved unadjusted survival (risk ratio 0.83, 95% CI 0.72 to 0.96, I2=0.0%), but conclusive benefit was not demonstrated for other outcomes. In retrospective studies, tocilizumab was associated with less severe outcomes on an Ordinal Scale (generalised OR 1.34, 95% CI 1.10 to 1.64, I2=98%) and adjusted mortality risk (HR 0.52, 95% CI 0.41 to 0.66, I2=76.6%). The mean difference in duration of hospitalisation was 0.36 days (95% CI -0.07 to 0.80, I2=93.8%). There was substantial heterogeneity in retrospective studies, and estimates should be interpreted cautiously. Other immunomodulatory agents showed similar effects to tocilizumab, but insufficient data precluded meta-analysis by agent. CONCLUSION: Tocilizumab was associated with a lower relative risk of mortality in prospective studies, but effects were inconclusive for other outcomes. Current evidence for the efficacy of anakinra, siltuximab or sarilumab in COVID-19 is insufficient, with further studies urgently needed for conclusive findings. PROSPERO REGISTRATION NUMBER: CRD42020176375.

Gene expression and in situ protein profiling of candidate SARS-CoV-2 receptors in human airway epithelial cells and lung tissue.

In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged, causing the coronavirus disease 2019 (COVID-19) pandemic. SARS-CoV, the agent responsible for the 2003 SARS outbreak, utilises angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) host molecules for viral entry. ACE2 and TMPRSS2 have recently been implicated in SARS-CoV-2 viral infection. Additional host molecules including ADAM17, cathepsin L, CD147 and GRP78 may also function as receptors for SARS-CoV-2.To determine the expression and in situ localisation of candidate SARS-CoV-2 receptors in the respiratory mucosa, we analysed gene expression datasets from airway epithelial cells of 515 healthy subjects, gene promoter activity analysis using the FANTOM5 dataset containing 120 distinct sample types, single cell RNA sequencing (scRNAseq) of 10 healthy subjects, proteomic datasets, immunoblots on multiple airway epithelial cell types, and immunohistochemistry on 98 human lung samples.We demonstrate absent to low ACE2 promoter activity in a variety of lung epithelial cell samples and low ACE2 gene expression in both microarray and scRNAseq datasets of epithelial cell populations. Consistent with gene expression, rare ACE2 protein expression was observed in the airway epithelium and alveoli of human lung, confirmed with proteomics. We present confirmatory evidence for the presence of TMPRSS2, CD147 and GRP78 protein in vitro in airway epithelial cells and confirm broad in situ protein expression of CD147 and GRP78 in the respiratory mucosa.Collectively, our data suggest the presence of a mechanism dynamically regulating ACE2 expression in human lung, perhaps in periods of SARS-CoV-2 infection, and also suggest that alternative receptors for SARS-CoV-2 exist to facilitate initial host cell infection.

Clinical quantification of the integrin αvß6 by [18F]FB-A20FMDV2 positron emission tomography in healthy and fibrotic human lung (PETAL Study).

PURPOSE: The RGD-integrin, αvß6, plays a role in the pathogenesis of pulmonary fibrosis through activation of transforming growth factor beta (TGFß). This study sought to quantify expression of αvß6 in the lungs of healthy humans and subjects with pulmonary fibrosis using the αvß6-selective [18F]FB-A20FMDV2 PET ligand. METHODS: [18F]FB-A20FMDV2 PET/CT scans were performed in healthy subjects and those with fibrotic lung disease. Standard uptake values (SUV) and volume of distribution (VT) were used to quantify αvß6 expression. In subjects with fibrotic lung disease, qualitative assessment of the relationship between αvß6 expression and the distribution of fibrosis on high resolution computed tomography was conducted. RESULTS: A total of 15 participants (6 healthy, 7 with idiopathic pulmonary fibrosis (IPF) and 2 with connective tissue disease (CTD) associated PF) were enrolled. VT and SUV of [18F]FB-A20FMDV2 were increased in the lungs of subjects with pulmonary fibrosis (PF) compared with healthy subjects. Geometric mean VT (95% CI) was 0.88 (0.60, 1.29) mL/cm3 for healthy subjects, and 1.40 (1.22, 1.61) mL/cm3 for subjects with IPF; and SUV was 0.54 (0.36, 0.81) g/mL for healthy subjects and 1.03 (0.86, 1.22) g/mL for subjects with IPF. The IPF/healthy VT ratio (geometric mean, (95% CI of ratio)) was 1.59 (1.09, 2.32) (probability ratio > 1 = 0.988)) and the SUV ratio was 1.91 (1.27, 2.87) (probability ratio > 1 = 0.996). Increased uptake of [18F]FB-A20FMDV2 in PF was predominantly confined to fibrotic areas. [18F]FB-A20FMDV2 measurements were reproducible at an interval of 2 weeks. [18F]FB-A20FMDV2 was safe and well tolerated. CONCLUSIONS: Lung uptake of [18F]FB-A20FMDV2, a measure of expression of the integrin αvß6, was markedly increased in subjects with PF compared with healthy subjects.

ß6 -integrin serves as a novel serum tumor marker for colorectal carcinoma.

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide and the need for novel biomarkers and therapeutic strategies to improve diagnosis and surveillance is obvious. This study aims to identify ß6 -integrin (ITGB6) as a novel serum tumor marker for diagnosis, prognosis, and surveillance of CRC. ITGB6 serum levels were validated in retro- and prospective CRC patient cohorts. ITGB6 serum levels were analyzed by ELISA. Using an initial cohort of 60 CRC patients, we found that ITGB6 is present in the serum of CRC, but not in non-CRC control patients. A cut-off of ≥2 ng/mL ITGB6 reveals 100% specificity for the presence of metastatic CRC. In an enlarged study cohort of 269 CRC patients, ITGB6 predicted the onset of metastatic disease and was associated with poor prognosis. Those data were confirmed in an independent, prospective cohort consisting of 40 CRC patients. To investigate whether ITGB6 can also be used for tumor surveillance, serum ITGB6-levels were assessed in 26 CRC patients, pre- and post-surgery, as well as during follow-up visits. After complete tumor resection, ITGB6 serum levels declined completely. During follow-up, a new rise in ITGB6 serum levels indicated tumor recurrence or the onset of new metastasis as confirmed by CT scan. ITGB6 was more accurate for prognosis of advanced CRC and for tumor surveillance as the established marker carcinoembryonic antigen (CEA). Our findings identify ITGB6 as a novel serum marker for diagnosis, prognosis, and surveillance of advanced CRC. This might essentially contribute to an optimized patient care.

Review of the British Thoracic Society Winter Meeting 2018, 5-7 December 2018, London, UK.

INTRODUCTION: The Winter Meeting of the British Thoracic Society (BTS) is a platform for the latest clinical and scientific research in respiratory medicine. This review summarises some key symposia and presentations from the BTS Winter Meeting 2018. METHODS: Key symposia and research presentations from the BTS Winter Meeting 2018 were attended and reviewed by the authors. RESULTS: The seminal messages from the latest clinical and scientific research covering a range of respiratory diseases, including asthma, interstitial lung disease, infection, cystic fibrosis, pulmonary vascular disease, pleural disease and occupational lung disease were summarised in this review. DISCUSSION: The BTS Winter Meeting 2018 brought the very best of respiratory research to an audience of scientists, physicians, nurses and allied health professionals. The Winter Meeting continues to be a highlight of the UK respiratory research calendar, and we look forward to the next meeting in December 2019.

Patient-reported distress can aid clinical decision-making in idiopathic pulmonary fibrosis: analysis of the PROFILE cohort.

Idiopathic pulmonary fibrosis is a progressive and fatal interstitial lung disease. We aimed to determine if patient response to a palliative assessment survey could predict disease progression or death.We undertook a cross-sectional study in a UK clinical cohort of incident cases. Rasch-based methodology provided a disease distress value from an abridged 11-item model of the original 45-item survey. Distress values were compared with measures of lung function. Disease progression or mortality alone was predicted at 12 months from survey completion, with risk of death assessed at 3, 6 and 12 months.Disease distress values were negatively correlated with lung function (r=-0.275 for the percentage predicted diffusing capacity of the lung for carbon monoxide). Expected survey scores computed from distress values could distinguish disease progression (n=8.8, p=0.004) and death (n=10.2, p=0.002) from no disease progression (n=6.9). Actual survey scores predicted disease progression and death with an area under the curve of 0.60 and 0.64, respectively. Each point increment in actual score increased risk of 12-month mortality by 10%; almost 43% of people scoring above 18 did not survive beyond 105 days.We define a short questionnaire that can score disease distress and predict prognosis, thus assisting clinical decision-making in progressive fibrosis.

Interplay between EZH2 and G9a Regulates CXCL10 Gene Repression in Idiopathic Pulmonary Fibrosis.

Selective repression of the antifibrotic gene CXCL10 contributes to tissue remodeling in idiopathic pulmonary fibrosis (IPF). We have previously reported that histone deacetylation and histone H3 lysine 9 (H3K9) methylation are involved in CXCL10 repression. In this study, we explored the role of H3K27 methylation and the interplay between the two histone lysine methyltransferases enhancer of zest homolog 2 (EZH2) and G9a in CXCL10 repression in IPF. By applying chromatin immunoprecipitation, Re-ChIP, and proximity ligation assays, we demonstrated that, like G9a-mediated H3K9 methylation, EZH2-mediated histone H3 lysine 27 trimethylation (H3K27me3) was significantly enriched at the CXCL10 promoter in fibroblasts from IPF lungs (F-IPF) compared with fibroblasts from nonfibrotic lungs, and we also found that EZH2 and G9a physically interacted with each other. EZH2 knockdown reduced not only EZH2 and H3K27me3 but also G9a and H3K9me3, and G9a knockdown reduced not only G9 and H3K9me3 but also EZH2 and H3K27me3. Depletion and inhibition of EZH2 and G9a also reversed histone deacetylation and restored CXCL10 expression in F-IPF. Furthermore, treatment of fibroblasts from nonfibrotic lungs with the profibrotic cytokine transforming growth factor-ß1 increased EZH2, G9a, H3K27me3, H3K9me3, and histone deacetylation at the CXCL10 promoter, similar to that observed in F-IPF, which was correlated with CXCL10 repression and was prevented by EZH2 and G9a knockdown. These findings suggest that a novel and functionally interdependent interplay between EZH2 and G9a regulates histone methylation-mediated epigenetic repression of the antifibrotic CXCL10 gene in IPF. This interdependent interplay may prove to be a target for epigenetic intervention to restore the expression of CXCL10 and other antifibrotic genes in IPF.

Extracellular Matrix Cross-Linking Enhances Fibroblast Growth and Protects against Matrix Proteolysis in Lung Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterized by accumulation of extracellular matrix (ECM) proteins and fibroblast proliferation. ECM cross-linking enzymes have been implicated in fibrotic diseases, and we hypothesized that the ECM in IPF is abnormally cross-linked, which enhances fibroblast growth and resistance to normal ECM turnover. We used a combination of in vitro ECM preparations and in vivo assays to examine the expression of cross-linking enzymes and the effect of their inhibitors on fibroblast growth and ECM turnover. Lysyl oxidase-like 1 (LOXL1), LOXL2, LOXL3, and LOXL4 were expressed equally in control and IPF-derived fibroblasts. Transglutaminase 2 was more strongly expressed in IPF fibroblasts. LOXL2-, transglutaminase 2-, and transglutaminase-generated cross-links were strongly expressed in IPF lung tissue. Fibroblasts grown on IPF ECM had higher LOXL3 protein expression and transglutaminase activity than those grown on control ECM. IPF-derived ECM also enhanced fibroblast adhesion and proliferation compared with control ECM. Inhibition of lysyl oxidase and transglutaminase activity during ECM formation affected ECM structure as visualized by electron microscopy, and it reduced the enhanced fibroblast adhesion and proliferation of IPF ECM to control levels. Inhibition of transglutaminase, but not of lysyl oxidase, activity enhanced the turnover of ECM in vitro. In bleomycin-treated mice, during the postinflammatory fibrotic phase, inhibition of transglutaminases was associated with a reduction in whole-lung collagen. Our findings suggest that the ECM in IPF may enhance pathological cross-linking, which contributes to increased fibroblast growth and resistance to normal ECM turnover to drive lung fibrosis.

Review of the British Thoracic Society Winter Meeting 2017, 6-8 December 2017, London, UK.

This article reviews the British Thoracic Society Winter Meeting 2017 and summarises the new developments in scientific and clinical research across the breadth of respiratory medicine. The article discusses a number of symposia and selected abstract presentations from the meeting.

Optimising experimental research in respiratory diseases: an ERS statement.

Experimental models are critical for the understanding of lung health and disease and are indispensable for drug development. However, the pathogenetic and clinical relevance of the models is often unclear. Further, the use of animals in biomedical research is controversial from an ethical perspective.The objective of this task force was to issue a statement with research recommendations about lung disease models by facilitating in-depth discussions between respiratory scientists, and to provide an overview of the literature on the available models. Focus was put on their specific benefits and limitations. This will result in more efficient use of resources and greater reduction in the numbers of animals employed, thereby enhancing the ethical standards and translational capacity of experimental research.The task force statement addresses general issues of experimental research (ethics, species, sex, age, ex vivo and in vitro models, gene editing). The statement also includes research recommendations on modelling asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, lung infections, acute lung injury and pulmonary hypertension.The task force stressed the importance of using multiple models to strengthen validity of results, the need to increase the availability of human tissues and the importance of standard operating procedures and data quality.