VT20 method for Chartis assessment of collateral ventilation with flexible bronchoscopy under procedural sedation.

VT20 is applicable for Chartis assessments with conscious sedation and spontaneous ventilation or high-frequency jet ventilation, and the cut-off of ≤6 mL remains the same to distinguish between CV- and CV+ phenotypes https://bit.ly/3HG9iMQ.

Enzymatic Modulation of the Pulmonary Glycocalyx Enhances Susceptibility to Streptococcus pneumoniae.

The pulmonary epithelial glycocalyx is rich in glycosaminoglycans such as hyaluronan and heparan sulfate. Despite their presence, the importance of these glycosaminoglycans in bacterial lung infections remains elusive. To address this, we intranasally inoculated mice with Streptococcus pneumoniae in the presence or absence of enzymes targeting pulmonary hyaluronan and heparan sulfate, followed by characterization of subsequent disease pathology, pulmonary inflammation, and lung barrier dysfunction. Enzymatic degradation of hyaluronan and heparan sulfate exacerbated pneumonia in mice, as evidenced by increased disease scores and alveolar neutrophil recruitment. However, targeting epithelial hyaluronan in combination with Streptococcus pneumoniae infection further exacerbated systemic disease, indicated by elevated splenic bacterial load and plasma levels of pro-inflammatory cytokines. In contrast, enzymatic cleavage of heparan sulfate resulted in increased bronchoalveolar bacterial burden, lung damage and pulmonary inflammation in mice infected with Streptococcus pneumoniae. Accordingly, heparinase-treated mice also exhibited disrupted lung barrier integrity as evidenced by higher alveolar edema scores and vascular protein leakage into the airways. This finding was corroborated in a human alveolus-on-a-chip platform, confirming that heparinase treatment also disrupts the human lung barrier during Streptococcus pneumoniae infection. Notably, enzymatic pre-treatment with either hyaluronidase or heparinase also rendered human epithelial cells more sensitive to pneumococcal-induced barrier disruption, as determined by transepithelial electrical resistance measurements, consistent with our findings in murine pneumonia. Taken together, these findings demonstrate the importance of intact hyaluronan and heparan sulfate in limiting pneumococci-induced damage, pulmonary inflammation, and epithelial barrier function and integrity.

Frequency and clinical significance of Herpes simplex virus type 1/2 reactivation in adult patients with mild to moderately severe community-acquired pneumonia: a multicentre cohort study.

PURPOSE: This study assessed the frequency, clinical significance, and risk factors for Herpes simplex virus (HSV) reactivation in immunocompetent patients with community-acquired pneumonia (CAP). METHODS: The study included adult CAP-patients who were enrolled in the CAPNETZ study between 2007 and 2017 and had a residual sputum sample available for analysis. In addition to routine diagnostics, sputum and blood samples were tested for HSV-1/2 using PCR. Demographics, comorbidities, and CRB-65 score were compared between HSV-positive and negative patients using Fisher exact or Mann Whitney test. Logistic regression analyses investigated the influence of HSV reactivation on a modified hospital recovery scale (HRS) until day 7, divided into 3 categories (no oxygen therapy, oxygen therapy, ICU admission or death). RESULTS: Among 245 patients, HSV-1 and HSV-2 were detected in 30 patients (12.2%, 95%CI 8.7-16.9) and 0 patients, respectively. All HSV-positive patients were hospitalized, had a CRB-65 severity score of 0-2 and survived the first 28 day. In the HSV-positive group, patients had a non-significantly higher median age (70.5 versus 66 years) and a higher rate of oncological comorbidities (16.7% versus 8.8%) compared to the HSV-negative group. Distribution of co-pathogens and outcome parameters did not significantly differ between both groups. In a multivariate logistic regression model, age (AOR 1.029, p = 0.012) and CRB-65 score (AOR 1.709, p = 0.048), but not HSV-1 as single or co-pathogen were independently associated with higher HRS. CONCLUSION: Our study suggests that HSV-1 reactivation is common in CAP but might not be associated with specific risk factors or a complicated disease course.

The life-saving benefit of dexamethasone in severe COVID-19 is linked to a reversal of monocyte dysregulation.

Dexamethasone is a life-saving treatment for severe COVID-19, yet its mechanism of action is unknown, and many patients deteriorate or die despite timely treatment initiation. Here, we identify dexamethasone treatment-induced cellular and molecular changes associated with improved survival in COVID-19 patients. We observed a reversal of transcriptional hallmark signatures in monocytes associated with severe COVID-19 and the induction of a monocyte substate characterized by the expression of glucocorticoid-response genes. These molecular responses to dexamethasone were detected in circulating and pulmonary monocytes, and they were directly linked to survival. Monocyte single-cell RNA sequencing (scRNA-seq)-derived signatures were enriched in whole blood transcriptomes of patients with fatal outcome in two independent cohorts, highlighting the potential for identifying non-responders refractory to dexamethasone. Our findings link the effects of dexamethasone to specific immunomodulation and reversal of monocyte dysregulation, and they highlight the potential of single-cell omics for monitoring in vivo target engagement of immunomodulatory drugs and for patient stratification for precision medicine approaches.

Single-cell-resolved interspecies comparison shows a shared inflammatory axis and a dominant neutrophil-endothelial program in severe COVID-19.

A key issue for research on COVID-19 pathogenesis is the lack of biopsies from patients and of samples at the onset of infection. To overcome these hurdles, hamsters were shown to be useful models for studying this disease. Here, we further leverage the model to molecularly survey the disease progression from time-resolved single-cell RNA sequencing data collected from healthy and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected Syrian and Roborovski hamster lungs. We compare our data to human COVID-19 studies, including bronchoalveolar lavage, nasal swab, and postmortem lung tissue, and identify a shared axis of inflammation dominated by macrophages, neutrophils, and endothelial cells, which we show to be transient in Syrian and terminal in Roborovski hamsters. Our data suggest that, following SARS-CoV-2 infection, commitment to a type 1- or type 3-biased immunity determines moderate versus severe COVID-19 outcomes, respectively.

Resurgence of common respiratory viruses in patients with community-acquired pneumonia (CAP)-A prospective multicenter study.

BACKGROUND: Community-acquired pneumonia (CAP) is a major global cause of death and hospitalization. Bacteria or community-acquired viruses (CARVs) cause CAP. COVID-19 associated restrictions effectively reduced the circulation of CARVs. OBJECTIVES: The aim of this study was to analyze the proportion of CARVs in adult patients with CAP from mid-2020 to mid-2023. Specifically, we aimed to compare the rate of influenza virus, SARS-CoV-2, and RSV detections in patients aged 18-59 years and ≥60 years. STUDY DESIGN: We analyze the proportion of 21 community-acquired respiratory viruses (CARVs) and three atypical bacteria (Bordetella pertussis, Legionella pneumophila, and Mycoplasma pneumoniae) in nasopharyngeal swab samples using molecular multiplex methods within the prospective, multicentre, multinational study of the German study Group CAPNETZ. We used stringent inclusion criteria throughout the study. RESULTS: We identified CARVs in 364/1,388 (26.2 %) patients. In detail, we detected SARS-CoV-2 in 210/1,388 (15.1 %), rhino-/enterovirus in 64/1,388 (4.6 %), influenza virus in 23/1,388 (1.6 %) and RSV in 17/1,388 (1.2 %) of all patients. We detected RSV and influenza more frequently in patients ≥60 years, especially in 22/23 compared to the previous season. None of the atypical bacteria were detected. CONCLUSIONS: Beginning in 2023, we demonstrate a re-emergence of CARVs in CAP patients. Effective vaccines or specific antiviral therapies for more than two thirds of the detected viral infections are currently available. High detection rates of vaccine-preventable viruses in older age groups support targeted vaccination campaigns.

IL-33 controls IL-22-dependent antibacterial defense by modulating the microbiota.

IL-22 plays a critical role in defending against mucosal infections, but how IL-22 production is regulated is incompletely understood. Here, we show that mice lacking IL-33 or its receptor ST2 (IL-1RL1) were more resistant to Streptococcus pneumoniae lung infection than wild-type animals and that single-nucleotide polymorphisms in IL33 and IL1RL1 were associated with pneumococcal pneumonia in humans. The effect of IL-33 on S. pneumoniae infection was mediated by negative regulation of IL-22 production in innate lymphoid cells (ILCs) but independent of ILC2s as well as IL-4 and IL-13 signaling. Moreover, IL-33's influence on IL-22-dependent antibacterial defense was dependent on housing conditions of the mice and mediated by IL-33's modulatory effect on the gut microbiota. Collectively, we provide insight into the bidirectional crosstalk between the innate immune system and the microbiota. We conclude that both genetic and environmental factors influence the gut microbiota, thereby impacting the efficacy of antibacterial immune defense and susceptibility to pneumonia.

Comparison of clinical outcomes in hospitalized patients with COVID-19 or non-COVID-19 community-acquired pneumonia in a prospective observational cohort study.

PURPOSE: Coronavirus disease 2019 (COVID-19) and non-COVID-19 community-acquired pneumonia (NC-CAP) often result in hospitalization with considerable risks of mortality, ICU treatment, and long-term morbidity. A comparative analysis of clinical outcomes in COVID-19 CAP (C-CAP) and NC-CAP may improve clinical management. METHODS: Using prospectively collected CAPNETZ study data (January 2017 to June 2021, 35 study centers), we conducted a comprehensive analysis of clinical outcomes including in-hospital death, ICU treatment, length of hospital stay (LOHS), 180-day survival, and post-discharge re-hospitalization rate. Logistic regression models were used to examine group differences between C-CAP and NC-CAP patients and associations with patient demography, recruitment period, comorbidity, and treatment. RESULTS: Among 1368 patients (C-CAP: n = 344; NC-CAP: n = 1024), C-CAP showed elevated adjusted probabilities for in-hospital death (aOR 4.48 [95% CI 2.38-8.53]) and ICU treatment (aOR 8.08 [95% CI 5.31-12.52]) compared to NC-CAP. C-CAP patients were at increased risk of LOHS over seven days (aOR 1.88 [95% CI 1.47-2.42]). Although ICU patients had similar in-hospital mortality risk, C-CAP was associated with length of ICU stay over seven days (aOR 3.59 [95% CI 1.65-8.38]). Recruitment period influenced outcomes in C-CAP but not in NC-CAP. During follow-up, C-CAP was linked to a reduced risk of re-hospitalization and mortality post-discharge (aOR 0.43 [95% CI 0.27-0.70]). CONCLUSION: Distinct clinical trajectories of C-CAP and NC-CAP underscore the need for adapted management to avoid acute and long-term morbidity and mortality amid the evolving landscape of CAP pathogens.

Soluble ACE2 correlates with severe COVID-19 and can impair antibody responses.

Identifying immune modulators that impact neutralizing antibody responses against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is of great relevance. We postulated that high serum concentrations of soluble angiotensin-converting enzyme 2 (sACE2) might mask the spike and interfere with antibody maturation toward the SARS-CoV-2-receptor-binding motif (RBM). We tested 717 longitudinal samples from 295 COVID-19 patients and showed a 2- to 10-fold increase of enzymatically active sACE2 (a-sACE2), with up to 1 µg/mL total sACE2 in moderate and severe patients. Fifty percent of COVID-19 sera inhibited ACE2 activity, in contrast to 1.3% of healthy donors and 4% of non-COVID-19 pneumonia patients. A mild inverse correlation of a-sACE2 with RBM-directed serum antibodies was observed. In silico, we show that sACE2 concentrations measured in COVID-19 sera can disrupt germinal center formation and inhibit timely production of high-affinity antibodies. We suggest that sACE2 is a biomarker for COVID-19 and that soluble receptors may contribute to immune suppression informing vaccine design.

Clinically used broad-spectrum antibiotics compromise inflammatory monocyte-dependent antibacterial defense in the lung.

Hospital-acquired pneumonia (HAP) is associated with high mortality and costs, and frequently caused by multidrug-resistant (MDR) bacteria. Although prior antimicrobial therapy is a major risk factor for HAP, the underlying mechanism remains incompletely understood. Here, we demonstrate that antibiotic therapy in hospitalized patients is associated with decreased diversity of the gut microbiome and depletion of short-chain fatty acid (SCFA) producers. Infection experiments with mice transplanted with patient fecal material reveal that these antibiotic-induced microbiota perturbations impair pulmonary defense against MDR Klebsiella pneumoniae. This is dependent on inflammatory monocytes (IMs), whose fatty acid receptor (FFAR)2/3-controlled and phagolysosome-dependent antibacterial activity is compromized in mice transplanted with antibiotic-associated patient microbiota. Collectively, we characterize how clinically relevant antibiotics affect antimicrobial defense in the context of human microbiota, and reveal a critical impairment of IM´s antimicrobial activity. Our study provides additional arguments for the rational use of antibiotics and offers mechanistic insights for the development of novel prophylactic strategies to protect high-risk patients from HAP.

Activin A levels are raised during human tuberculosis and blockade of the activin signaling axis influences murine responses to M. tuberculosis infection.

Activin A strongly influences immune responses; yet, few studies have examined its role in infectious diseases. We measured serum activin A levels in two independent tuberculosis (TB) patient cohorts and in patients with pneumonia and sarcoidosis. Serum activin A levels were increased in TB patients compared to healthy controls, including those with positive tuberculin skin tests, and paralleled severity of disease, assessed by X-ray scores. In pneumonia patients, serum activin A levels were also raised, but in sarcoidosis patients, levels were lower. To determine whether blockade of the activin A signaling axis could play a functional role in TB, we harnessed a soluble activin type IIB receptor fused to human IgG1 Fc, ActRIIB-Fc, as a ligand trap in a murine TB model. The administration of ActRIIB-Fc to Mycobacterium tuberculosis-infected mice resulted in decreased bacterial loads and increased numbers of CD4 effector T cells and tissue-resident memory T cells in the lung. Increased frequencies of tissue-resident memory T cells corresponded with downregulated T-bet expression in lung CD4 and CD8 T cells. Altogether, the results suggest a disease-exacerbating role of ActRIIB signaling pathways. Serum activin A may be useful as a biomarker for diagnostic triage of active TB or monitoring of anti-tuberculosis therapy. IMPORTANCE: Tuberculosis remains the leading cause of death by a bacterial pathogen. The etiologic agent of tuberculosis, Mycobacterium tuberculosis, can remain dormant in the infected host for years before causing disease. Significant effort has been made to identify biomarkers that can discriminate between latently infected and actively diseased individuals. We found that serum levels of the cytokine activin A were associated with increased lung pathology and could discriminate between active tuberculosis and tuberculin skin-test-positive healthy controls. Activin A signals through the ActRIIB receptor, which can be blocked by administration of the ligand trap ActRIIB-Fc, a soluble activin type IIB receptor fused to human IgG1 Fc. In a murine model of tuberculosis, we found that ActRIIB-Fc treatment reduced mycobacterial loads. Strikingly, ActRIIB-Fc treatment significantly increased the number of tissue-resident memory T cells. These results suggest a role for ActRIIB signaling pathways in host responses to Mycobacterium tuberculosis and activin A as a biomarker of ongoing disease.

Characterization of Commercially Available Human Primary Alveolar Epithelial Cells.

In vitro lung research requires appropriate cell culture models that adequately mimic in vivo structure and function. Previously, researchers extensively used commercially available and easily expandable A549 and NCI-H441 cells, which replicate some but not all features of alveolar epithelial cells. Specifically, these cells are often restricted by terminally altered expression while lacking important alveolar epithelial characteristics. Of late, human primary alveolar epithelial cells (hPAEpCs) have become commercially available but are so far poorly specified. Here, we applied a comprehensive set of technologies to characterize their morphology, surface marker expression, transcriptomic profile, and functional properties. At optimized seeding numbers of 7,500 cells per square centimeter and growth at a gas-liquid interface, hPAEpCs formed regular monolayers with tight junctions and amiloride-sensitive transepithelial ion transport. Electron microscopy revealed lamellar body and microvilli formation characteristic for alveolar type II cells. Protein and single-cell transcriptomic analyses revealed expression of alveolar type I and type II cell markers; yet, transcriptomic data failed to detect NKX2-1, an important transcriptional regulator of alveolar cell differentiation. With increasing passage number, hPAEpCs transdifferentiated toward alveolar-basal intermediates characterized as SFTPC-, KRT8high, and KRT5- cells. In spite of marked changes in the transcriptome as a function of passaging, Uniform Manifold Approximation and Projection plots did not reveal major shifts in cell clusters, and epithelial permeability was unaffected. The present work delineates optimized culture conditions, cellular characteristics, and functional properties of commercially available hPAEpCs. hPAEpCs may provide a useful model system for studies on drug delivery, barrier function, and transepithelial ion transport in vitro.

Pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH) in the German CAPNETZ-Cohort.

OBJECTIVES: The objective of this study was to identify the pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH), and to compare it with a matched HIV negative group in order to reassess therapeutic strategies for PLWH. METHODS: Seventy-three (n = 73) PLWH (median CD4 3-6 months before CAP: 515/µl; SD 309) with community acquired pneumonia (CAP) were matched with 218 HIV-negative CAP controls in a prospective study design. Pathogen identifications used blood culture, samples from the upper and lower respiratory tract (culture and multiplex PCR) and urinary pneumococcal and legionella antigen test. RESULTS: Although the vaccination rate among PLWH with CAP was significantly higher (pneumococcal vaccination: 27.4 vs. 8.3%, p < 0.001; influenza vaccination: 34.2 vs. 17.4%, p = 0.009), pneumococci were found most frequently as pathogen among both PLWH (n = 19/21.3%) and controls (n = 34/17.2%; p = 0.410), followed by Haemophilus influenzae (PLWH, n = 12/13.5%, vs. controls, n = 25 / 12.6%; p = 0.850). Staphylococcus aureus was found equally in 20.2 and 19.2% in PLWH and controls, but infection or colonization could not be distinguished. Mortality during 6-month follow-up was significantly higher for PLWH (5/73, or 6.8%) versus controls (3/218, or 1.4%), however with lower case numbers than previously reported. Typical HIV-associated pathogens such as Pneumocystis jirovecii were found only exceptionally. CONCLUSIONS: Our study underscores the persistent clinical burden of CAP for PLWH. From pathogen perspective, empirical antibiotic treatment for CAP in PLWH on antiretroviral therapy should cover pneumococci and Haemophilus influenzae and may be adopted from valid common recommendations.

Validation of risk scores for prediction of severe pneumonia in kidney transplant recipients hospitalized with community-acquired pneumonia.

PURPOSE: Risk scores for community-acquired pneumonia (CAP) are widely used for standardized assessment in immunocompetent patients and to identify patients at risk for severe pneumonia and death. In immunocompromised patients, the prognostic value of pneumonia-specific risk scores seems to be reduced, but evidence is limited. The value of different pneumonia risk scores in kidney transplant recipients (KTR) is not known. METHODS: Therefore, we retrospectively analyzed 310 first CAP episodes after kidney transplantation in 310 KTR. We assessed clinical outcomes and validated eight different risk scores (CRB-65, CURB-65, DS-CRB-65, qSOFA, SOFA, PSI, IDSA/ATS minor criteria, NEWS-2) for the prognosis of severe pneumonia and in-hospital mortality. Risk scores were assessed up to 48 h after admission, but always before an endpoint occurred. Multiple imputation was performed to handle missing values. RESULTS: In total, 16 out of 310 patients (5.2%) died, and 48 (15.5%) developed severe pneumonia. Based on ROC analysis, sequential organ failure assessment (SOFA) and national early warning score 2 (NEWS-2) performed best, predicting severe pneumonia with AUC of 0.823 (0.747-0.880) and 0.784 (0.691-0.855), respectively. CONCLUSION: SOFA and NEWS-2 are best suited to identify KTR at risk for the development of severe CAP. In contrast to immunocompetent patients, CRB-65 should not be used to guide outpatient treatment in KTR, since there is a 7% risk for the development of severe pneumonia even in patients with a score of zero.

RSV vaccination strategies for high-risk patients 2023: a collaborative position paper by leading German medical societies and organizations.

Respiratory syncytial virus (RSV) inflicts severe illness and courses of infections not only in neonates, infants, and young children, but also causes significant morbidity and mortality in older adults and in people with immunosuppression, hemato-oncologic disease, chronic lung disease, or cardiovascular disease. In June and August 2023, effective vaccines against RSV were approved for the first time by the European Medicines Agency (EMA) for the EU. The respective pivotal studies showed a very high efficacy of the vaccine in preventing severe RSV-associated respiratory infections. At this point, use of the respective vaccines is restricted to persons aged 60 years or older, according to the registration studies. We therefore recommend use of the vaccination in persons aged 60 years or older. In addition, we recommend use of the vaccination in adults of any age with severe pulmonary or cardiovascular pre-existing conditions, as well as in adults with significant immune compromise, after individual consultation with the treating physician. Cost coverage can be applied for individually with the responsible health insurance company.

Reexpansion pulmonary edema after treatment of primary spontaneous pneumothorax.

A 24-year-old male patient, without further symptoms or comorbidities presented to the emergency room with acute dyspnea after heavy lifting two days before. On auscultation an attenuated vesicular breath was noticed on the right lung. In the initial chest radiograph a right-sided primary spontaneous pneumothorax with minor mediastinal shift was diagnosed. After insertion of a 12-French chest tube the patient's clinical condition deteriorated. The following chest radiograph and computed tomography of the thorax showed a reexpansion pulmonary edema in the right lung. The patient was admitted to the ICU and supportive treatment was initiated. Pulmonary reexpansion edema after drainage of a pneumothorax is a very rare complication with mortality rates reaching up to 20%. The exact pathophysiology remains unknown. Typical Symptoms include dyspnea, hypotension, and tachycardia. To minimize the risk of a pulmonary reexpansion edema, not more than 1200-1800 ml of air should be drained at once and the drainage should be stopped when the patient starts coughing.

Efficacy and safety of zapnometinib in hospitalised adult patients with COVID-19 (RESPIRE): a randomised, double-blind, placebo-controlled, multicentre, proof-of-concept, phase 2 trial.

Background: Zapnometinib is an oral, non-ATP-competitive, small-molecule inhibitor of MEK1/MEK2 with immunomodulatory and antiviral properties. We aimed to investigate the safety and efficacy of zapnometinib in patients with COVID-19. Methods: In this randomised, double-blind, placebo-controlled, multicentre, proof-of-concept, phase 2 trial, we recruited hospitalised adults with moderate or severe COVID-19 from 18 hospitals in Germany, India, Romania, South Africa, and Spain. Those requiring ICU admission or ventilator support at screening or randomisation were excluded. Patients were randomly assigned (1:1) to receive oral zapnometinib (900 mg on Day 1; 600 mg on Days 2-6) or matching placebo, on top of standard of care. Randomisation, stratified by baseline clinical severity status (CSS 3 or 4, measured on a 7-point ordinal scale), was done using Interactive Response Technology. Patients, investigators, and the sponsor were masked to treatment allocation. The primary endpoint was CSS at Day 15 and was conducted on the full analysis set (FAS: all patients who were randomised to the study, received at least one dose of study medication and had at least one post-dose assessment of CSS, as randomised). Safety analyses were conducted on the safety analysis set (all study participants who received at least one dose of study medication, as treated). This study is registered at ClinicalTrials.gov (NCT04776044) and EudraCT (2020-004206-59). Findings: The trial was terminated early as the emergence of the Omicron variant impacted recruitment. Between 12th April 2021 and 9th August 2022, 104 of the planned 220 patients were enrolled and randomly assigned, 103 were treated, and 101 were included in the FAS (zapnometinib: n = 50; placebo: n = 51). The primary outcome was not significantly different between the two groups, but patients on zapnometinib had higher odds of improved CSS versus placebo (odds ratio [OR] 1.54 [95% CI 0.72-3.33]; p = 0.26). Predefined subgroup analyses identified trends for improved CSS in patients with severe disease at baseline (OR 2.57 [0.76-8.88]; p = 0.13) and non-Omicron variants (OR 2.36 [0.85-6.71]; p = 0.10); the p value of the CSS subgroup by Treatment interaction term in the model was p = 0.28. The frequency and intensity of adverse events was low and similar between arms. Twenty (39.2%) patients treated with zapnometinib experienced adverse events compared with eighteen (34.6%) patients treated with placebo. One patient receiving zapnometinib and two patients receiving placebo died during the study. None of the deaths were considered related to study medication. Interpretation: These results provide proof-of-concept for the innovative approach of targeting the Raf/MEK/ERK pathway in patients with hospitalised moderate/severe COVID-19. Further clinical studies will be required to evaluate the clinical benefit of zapnometinib in this and other indications. Funding: Atriva Therapeutics GmbH and the Federal Ministry of Education and Research, Germany.

Cationic LNP-formulated mRNA expressing Tie2-agonist in the lung endothelium prevents pulmonary vascular leakage.

Dysfunction of endothelial cells (ECs) lining the inner surface of blood vessels are causative for a number of diseases. Hence, the ability to therapeutically modulate gene expression within ECs is of high therapeutic value in treating diseases such as those associated with lung edema. mRNAs formulated with lipid nanoparticles (LNPs) have emerged as a new drug modality to induce transient protein expression for modulating disease-relevant signal transduction pathways. In the study presented here, we tested the effect of a novel synthetic, nucleoside-modified mRNA encoding COMP-Ang1 (mRNA-76) formulated into a cationic LNP on attenuating inflammation-induced vascular leakage. After intravenous injection, the respective mRNA was found to be delivered almost exclusively to the ECs of the lung, while sparing other vascular beds and bypassing the liver. The mode of action of mRNA-76, such as its activation of the Tie2 signal transduction pathway, was tested by pharmacological studies in vitro and in vivo in respective mouse models. mRNA-76 was found to prevent lung vascular leakage/lung edema as well as neutrophil infiltration in a lipopolysaccharide-challenging model.

Protocol of the Berlin Long-term Observation of Vascular Events (BeLOVE): a prospective cohort study with deep phenotyping and long-term follow up of cardiovascular high-risk patients.

INTRODUCTION: The Berlin Long-term Observation of Vascular Events is a prospective cohort study that aims to improve prediction and disease-overarching mechanistic understanding of cardiovascular (CV) disease progression by comprehensively investigating a high-risk patient population with different organ manifestations. METHODS AND ANALYSIS: A total of 8000 adult patients will be recruited who have either suffered an acute CV event (CVE) requiring hospitalisation or who have not experienced a recent acute CVE but are at high CV risk. An initial study examination is performed during the acute treatment phase of the index CVE or after inclusion into the chronic high risk arm. Deep phenotyping is then performed after ~90 days and includes assessments of the patient's medical history, health status and behaviour, cardiovascular, nutritional, metabolic, and anthropometric parameters, and patient-related outcome measures. Biospecimens are collected for analyses including 'OMICs' technologies (e.g., genomics, metabolomics, proteomics). Subcohorts undergo MRI of the brain, heart, lung and kidney, as well as more comprehensive metabolic, neurological and CV examinations. All participants are followed up for up to 10 years to assess clinical outcomes, primarily major adverse CVEs and patient-reported (value-based) outcomes. State-of-the-art clinical research methods, as well as emerging techniques from systems medicine and artificial intelligence, will be used to identify associations between patient characteristics, longitudinal changes and outcomes. ETHICS AND DISSEMINATION: The study was approved by the Charité-Universitätsmedizin Berlin ethics committee (EA1/066/17). The results of the study will be disseminated through international peer-reviewed publications and congress presentations. STUDY REGISTRATION: First study phase: Approved WHO primary register: German Clinical Trials Register: https://drks.de/search/de/trial/DRKS00016852; WHO International Clinical Registry Platform: http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00016852. Recruitment started on July 18, 2017.Second study phase: Approved WHO primary register: German Clinical Trials Register DRKS00023323, date of registration: November 4, 2020, URL: http://www.drks.de/ DRKS00023323. Recruitment started on January 1, 2021.