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Frauke Pedersen,1,2 Frederik Trinkmann,3 Mustafa Abdo,2 Anne-Marie Kirsten,1 Klaus F Rabe,2 Henrik Watz,1 Simonetta Baraldo,4 Marina Saetta,4 Jens M Hohlfeld,5,6 Olaf Holz5 1Pulmonary Research Institute at LungenClinic Grosshansdorf, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Grosshansdorf, Germany; 2LungenClinic Grosshansdorf, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Grosshansdorf, Germany; 3Pneumology and Critical Care Medicine, Thoraxklinik at University Hospital Heidelberg, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany; 4Department of Cardiac, Thoracic, Vascular Sciences and Public Health, Respiratory Diseases Clinic, University of Padova, Padova, Italy; 5Fraunhofer ITEM, Clinical Airway Research - Biomedical Research in End-Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany; 6Department of Respiratory Medicine, Hannover Medical School (MHH), Biomedical Research in End-Stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, GermanyCorrespondence: Frauke PedersenPulmonary Research Institute at LungenClinic Grosshansdorf, Wöhrendamm 80, Grosshansdorf, D-22927, GermanyTel +49-4102-6016845Fax +49-4102-8881114Email f.pedersen@pulmoresearch.dePurpose: We recently introduced a sputum cell quality score to rate how cell morphology, cellular debris and squamous cell contamination influence inflammatory cell identification during microscopic evaluation. However, sputum cell quality is generally not considered for the interpretation of sputum fluid phase biomarkers. Therefore, we compared the soluble protein concentrations between sputum samples with different cell quality. The impact of cell quality was compared to other factors potentially affecting soluble biomarker concentrations.Methods: A comprehensive sputum dataset from 154 clinically stable COPD patients was used to analyse the differences and the variability of sputum supernatant concentrations for 23 proteins between low, medium, and high sputum cell quality samples. A model was developed and tested to compare the impact of different factors on sputum supernatant protein levels.Results: Mean percentages of sputum macrophages, neutrophils, eosinophils, monocytes and lymphocytes showed no significant differences between low, medium and high cell quality levels. The mean percentage of squamous cells were lower, while total cell count/mL sputum and cell viability were significantly higher in sputum samples with higher cell quality. The concentrations of Interleukin-6, Interleukin-8 and Tumor Necrosis Factor Receptor 2 were significantly increased in sputum samples of higher cell quality. The variability of most protein concentrations declined with increasing cell quality levels. Sixteen proteins showed significantly negative correlations with the percentage of squamous cells. For 14 proteins we observed a positive correlation with cell number/mL sputum. Multiple regression analysis shows that generally less than 30% of the protein variability can be explained by the included factors.Conclusion: Sputum cell quality has a significant impact on some soluble biomarker concentrations in sputum supernatant. Sputum samples with low sputum cell quality show a higher variability of fluid phase proteins in comparison to medium and high sputum cell quality levels.Keywords: sputum cell quality score, soluble biomarkers, sputum supernatant

Olaf Holz,1,* David S DeLuca,2,* Stefan Roepcke,3 Thomas Illig,2 Klaus M Weinberger,4–6 Christian Schudt,7 Jens M Hohlfeld1,2 1Fraunhofer ITEM, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany; 2Hannover Medical School, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research, Hannover, Germany; 3Department of Biomarker Development, Takeda Pharmaceuticals International GmbH, Zürich, Switzerland; 4Biocrates Life Sciences AG, Innsbruck, Austria; 5Research Group for Clinical Bioinformatics, Private University for Health Sciences, Medical Informatics and Technology, Hall in Tirol, Austria; 6sAnalytiCo Ltd, Belfast, Ireland; 7Department of Biochemistry, ALTANA, Konstanz, Germany*These authors contributed equally to this workCorrespondence: Olaf HolzDepartment of Clinical Airway Research, Fraunhofer ITEM, Hannover 30625, GermanyTel +49-511-5350-8141Fax +49-511-5350-8250Email olaf.holz@item.fraunhofer.dePurpose: There is an ongoing demand for easily accessible biomarkers that reflect the physiological and pathophysiological mechanisms of COPD. To test if an exercise challenge could help to identify clinically relevant metabolic biomarkers in COPD.Patients and Methods: We performed two constant-load exercise challenges separated by 4 weeks including smokers with COPD (n=23/19) and sex- and age-matched healthy smokers (n=23/20). Two hours after a standardized meal venous blood samples were obtained before, 5 mins after the start, at the end of submaximal exercise, and following a recovery of 20 mins. Data analysis was performed using mixed- effects model, with the metabolite level as a function of disease, time point and interaction terms and using each individual’s resting level as reference.Results: Exercise duration was longer in healthy smokers but lactate levels were comparable between groups at all four time points. Glucose levels were increased in COPD. Glutamine was lower, while glutamate and arginine were higher in COPD. Branched-chain amino acids showed a stronger decline during exercise in healthy smokers. Carnitine and the acyl-carnitines C16 and C18:1 were increased in COPD. These metabolite levels and changes were reproducible in the second challenge.Conclusion: Higher serum glucose, evidence for impaired utilization of amino acids during exercise and a shift of energy metabolism to enhanced consumption of lipids could be early signs for a developing metabolic syndrome in COPD. In COPD patients, deviations of energy and nitrogen metabolism are amplified by an exercise challenge.Keywords: targeted metabolomics, biomarker, airway inflammation

Frauke Pedersen,1,2 Ulrich M Zissler,3 Henrik Watz,2 Klaus F Rabe,1 Jens M Hohlfeld,4,5 Olaf Holz41LungenClinic Grosshansdorf, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Grosshansdorf, Germany; 2Pulmonary Research Institute at LungenClinic Grosshansdorf, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Grosshansdorf, Germany; 3Center of Allergy & Environment (ZAUM), Technical University of Munich and Helmholtz Center Munich, German Research Center for Environmental Health, Germany, Member of the German Center for Lung Research (DZL), Munich, Germany; 4Fraunhofer ITEM, Clinical Airway Research – Biomedical Research in End-stage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany; 5Department of Respiratory Medicine, Hannover Medical School (MHH), Biomedical Research in End-stage and Obstructive Lung Disease Hannover (BREATH), Hannover, GermanyBackgroundInduced sputum is a method to assess airway inflammation in clinical trials for asthma and COPD.1–3 Sputum is a heterogeneous, viscous material containing inflammatory cell plugs, cellular debris, mucus, and saliva with squamous cells.The quality of sputum cell preparations for differential cell count analysis depends on multiple factors and can be highly variable.4,5 Percentage of squamous cell contamination (SQ%) is often used to assess the quality of sputum cell preparations.6Here, we evaluated a comprehensive quality score,7 which also includes an assessment of the inflammatory cell morphology and amount of cellular debris.

Olaf Holz,1,* Stefan Roepcke,2,* Henrik Watz,3 Uwe Tegtbur,4 Gezim Lahu,2 Jens M Hohlfeld1 1Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM), German Center for Lung Research (DZL, BREATH), Hannover, Germany; 2Takeda Pharmaceuticals International GmbH, Glattpark-Opfikon, Switzerland; 3Pulmonary Research Institute at Lung Clinic Grosshansdorf, German Center for Lung Research (DZL, ARCN), Grosshansdorf, 4Institute for Sports Medicine, Hannover Medical School (MHH), Hannover, Germany *These authors contributed equally to this work Abstract: There is an ongoing demand for easily accessible biomarkers related to pathophysiological processes in chronic obstructive pulmonary disease (COPD). Short-term intense exercise is known to increase the peripheral blood levels of cytokines. Therefore, we tested the potential and the repeatability of an exercise challenge to amplify seven serum biomarkers (interleukin 6 [IL6], C-reactive protein [CRP], myeloperoxidase [MPO], leukotriene B4, soluble intercellular adhesion molecule 1, soluble vascular cell adhesion molecule 1, and von Willebrand factor [VWF]) in smokers with and without COPD. Twenty-three smokers with moderate COPD (GOLD 2) and 23 sex- and age-matched healthy smokers underwent up to 30-minute submaximal, constant-load exercise (75% of maximum work load) on two occasions separated by 4 weeks (second challenge n=19/20). Serum samples were obtained before, 5 minutes after the start, at the end of exercise (maximum 30 minutes or until exhaustion), and after additional 20 minutes of rest. The median (interquartile range) exercise time until exhaustion in the two challenges was 10.0 (4.0) minutes and 10.0 (8.0) minutes in smokers with COPD and 22.0 (16.0) minutes and 26.5 (14.5) minutes in healthy smokers. The exercise challenge significantly increased the serum concentrations of IL6 and VWF, but decreased the concentrations of MPO. Healthy smokers showed a significantly greater increase (at the end of exercise compared to before exercise) in IL6 (P=0.01) and a larger decline (P=0.03) in MPO. The overall profile of the serum markers during the exercise challenge was shown to be repeatable in the second challenge. In summary, intense load exercise is capable of changing the concentration of inflammatory and endothelial function markers. Especially, the decline in the level of MPO, a marker closely related to cardiovascular risk, appears to be of clinical interest, as the exercise-induced decline might be related to the beneficial effects of physical activity in general. Keywords: serum biomarker, systemic inflammation, physical activity

Abstract Background The loss of alveolar walls is a hallmark of emphysema. As fibroblasts play an important role in the maintenance of alveolar structure, a change in fibroblast phenotype could be involved in the pathogenesis of this disease. In a previous study we found a reduced in vitro proliferation rate and number of population doublings of parenchymal lung fibroblasts from patients with emphysema and we hypothesized that these findings could be related to a premature cellular aging of these cells. In this study, we therefore compared cellular senescence markers and expression of respective genes between lung fibroblasts from patients with emphysema and control patients without COPD. Methods Primary lung fibroblasts were obtained from 13 patients with moderate to severe lung emphysema (E) and 15 controls (C) undergoing surgery for lung tumor resection or volume reduction (n = 2). Fibroblasts (8E/9C) were stained for senescence-associated β-galactosidase (SA-β-Gal). In independent cultures, DNA from lung fibroblasts (7E/8C) was assessed for mean telomere length. Two exploratory 12 k cDNA microarrays were used to assess gene expression in pooled fibroblasts (3E/3C). Subsequently, expression of selected genes was evaluated by quantitative PCR (qPCR) in fibroblasts of individual patients (10E/9C) and protein concentration was analyzed in the cell culture supernatant. Results The median (quartiles) percentage of fibroblasts positive for SA-β-Gal was 4.4 (3.2;4.7) % in controls and 16.0 (10.0;24.8) % in emphysema (p = 0.001), while telomere length was not different. Among the candidates for differentially expressed genes in the array (factor ≥ 3), 15 were upregulated and 121 downregulated in emphysema. qPCR confirmed the upregulation of insulin-like growth factor-binding protein (IGFBP)-3 and IGFBP-rP1 (p = 0.029, p = 0.0002), while expression of IGFBP-5, -rP2 (CTGF), -rP4 (Cyr61), FOSL1, LOXL2, OAZ1 and CDK4 was not different between groups. In line with the gene expression we found increased cell culture supernatant concentrations of IGFBP-3 (p = 0.006) in emphysema. Conclusion These data support the hypothesis that premature aging of lung fibroblasts occurs in emphysema, via a telomere-independent mechanism. The upregulation of the senescence-associated IGFBP-3 and -rP1 in emphysema suggests that inhibition of the action of insulin and insulin-like growth factors could be involved in the reduced in vitro-proliferation rate.

Rationale: Surfactant protein D (SP-D), a 43-kD collectin, is synthesized and secreted by airway epithelia as a dodecamer formed by assembly of four trimeric subunits. We have previously shown that the quaternary structure of SP-D can be altered during inflammatory lung injury through its modification by S-nitrosylation, which in turn alters its functional behavior producing a proinflammatory response in effector cells.Objectives: We hypothesized that alterations in structure and function of SP-D may occur in humans with acute allergic inflammation.Methods: Bronchoalveolar lavage (BAL) fluid was collected from 15 nonsmoking patients with mild intermittent allergic asthma before and 24 hours after segmental provocation with saline, allergen, LPS, and mixtures of allergen and LPS. Structural modifications of SP-D were analyzed by native and sodium dodecyl sulfate gel electrophoresis.Measurements and Main Results: The multimeric structure of native SP-D was found to be disrupted after provocation with allergen or a mixture of allergen and LPS. Interestingly, under reducing conditions, sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that 7 of 15 patients with asthma developed an abnormal cross-linked SP-D band after segmental challenge with either allergen or a mixture of allergen with LPS but not LPS alone. Importantly, patients with asthma with cross-linked SP-D demonstrated significantly higher levels of BAL eosinophils, nitrogen oxides, IL-4, IL-5, IL-13, and S-nitrosothiol-SP-D compared with patients without cross-linked SP-D.Conclusions: We conclude that segmental allergen challenge results in changes of SP-D multimeric structure and that these modifications are associated with an altered local inflammatory response in the distal airways. [ABSTRACT FROM AUTHOR]

Rationale: Epidermal growth factor receptor (EGFR) activation is implicated in mucin hypersecretion in chronic obstructive pulmonary disease (COPD). Objectives: To investigate the safety and efficacy of an inhaled EGFR antagonist (BIBW 2948) in COPD. Methods: Multicenter, double-blind, placebo-controlled trial of 4 weeks of treatment with two doses of BIBW 2948 (15 and 30 mg twice a day) on safety and mucin-related outcomes in 48 patients with COPD. The effect of BIBW 2948 on EGFR activation in airway epithelial cells was assessed using an ex vivo assay. Efficacy measures included the volume of mucin in the airway epithelium (Vs mu,bala) in bronchial biopsies and the expression of mucin genes in bronchial brushings. Measurements and Main Results: Inhaled BIBW 2948 induced a dose-related inhibition of EGFR internalization (reflecting decreased EGFR activation) in epithelial cells from treated subjects. However, BIBW 2948 was associated with a dose-related increase in adverse events, including reversible liver enzyme elevation (n = 2), and reduction in FEV(1). The changes in mucin stores and mucin gene expression were not significantly different in the pooled BIBW 2948 group versus placebo (volume of mucin per surface area of basal lamina = 0.22 +/- 7.11 vs. 0.47 +/- 8.06 mum(3)/mum(2); P = 0.93). However, in the 30 mg twice a day group, the reduction in epithelial mucin stores was greatest in subjects with the greatest degree of EGFR inhibition (Pearson r = 0.98; 95% confidence interval, 0.71-0.99). Conclusions: Four-week treatment with BIBW 2948 did not significantly decrease epithelial mucin stores and was poorly tolerated in patients with COPD. Ex vivo analyses suggest that higher doses may be more effective at both EGFR inhibition and decreases in mucin stores but that adverse events should be expected. Clinical trial registered with www.clinicaltrials.gov (NCT00423137). [ABSTRACT FROM AUTHOR]

Rationale: Epidemiologic studies have shown that exacerbation of asthma is modulated by environmental endotoxin. High levels of endotoxin are associated with asthma symptoms and the current use of asthma medication. However, the underlying mechanisms by which endotoxin modulates asthma are not completely understood.Objectives: The aim of the study was to test whether endotoxin enhances the response of individuals with allergic asthma to allergen, and to determine if this interaction is associated with increased numbers of antigen-presenting cells in the airways.Methods: Seventeen subjects with mild allergic asthma underwent segmental challenge with allergen, endotoxin, and the combination of both in three different lung segments via bronchoscopy. The cellular influx including monocytes, myeloid dendritic cells (mDCs), and plasmacytoid dendritic cells (pDCs), as well as the level of cytokines, were assessed in bronchoalveolar lavage fluid obtained 24 hours after segmental challenge. Monocytes, mDCs, and pDCs were isolated and their capacity to induce T cell proliferation was determined.Measurements and Main Results: Endotoxin enhanced the cellular response to allergen. The combination of allergen and endotoxin resulted in increased numbers of total cells, lymphocytes, neutrophils, eosinophils, monocytes, and mDCs, as well as increased levels of lipopolysaccharide-binding protein, IL-1alpha, IL-6, and tumor necrosis factor-alpha in the bronchoalveolar lavage fluid compared with allergen alone. Isolated mDCs but not pDCs induced a strong T cell proliferation in vitro.Conclusions: Endotoxin augments the allergic inflammation in the lungs of individuals with asthma, and induces an enhanced influx of monocytes and functionally active antigen-presenting mDCs into the respiratory tract. [ABSTRACT FROM AUTHOR]

Epidemiologic studies have shown an increased prevalence of allergic asthma in children living in a German smelter area (Hettstedt) compared with a cohort who live in a nonindustrialized area (Zerbst). However, it is not known whether ambient particles (particulate matter(2.5) [PM(2.5)]) from these areas induce distinct lung inflammation, which might be an explanation for this difference. Therefore, 100 microg of PM(2.5) suspensions, collected simultaneously in the two areas, were instilled through a bronchoscope into contralateral lung segments of 12 healthy volunteers. PM(2.5) from both Hettstedt and Zerbst increased the number of leukocytes in the bronchoalveolar lavage performed 24 hours later. PM(2.5) from Hettstedt, but not Zerbst, induced a significant influx of monocytes (Hettstedt: 7.0% vs. Zerbst: 4.3%) without influencing the expression of surface activation markers on monocytes and alveolar macrophages. Oxidant radical generation of bronchoalveolar lavage cells and cytokine concentration (interleukin-6 and tumor necrosis factor-alpha) in bronchoalveolar lavage fluid was significantly increased after instillation of Hettstedt PM(2.5). We conclude that environmentally relevant concentrations of PM(2.5) from the smelter area induced distinct airway inflammation in healthy subjects with a selective influx of monocytes and increased generation of oxidant radicals. The higher concentration of transition metals in PM(2.5) from Hettstedt might be responsible for this increased inflammation. [ABSTRACT FROM AUTHOR]

Background: Pulse wave velocity (PWV) in the pulmonary arteries (PA) is a marker of vascular stiffening. Currently, only phase-contrast (PC) MRI-based options exist to measure PA-PWV., Purpose: To test feasibility, repeatability, and correlation to clinical data of Phase-Resolved Functional Lung (PREFUL) MRI-based calculation of PA-PWV., Study Type: Retrospective., Subjects: 79 (26 female) healthy subjects (age range 19-78), 58 (24 female) patients with chronic obstructive pulmonary disease (COPD, age range 40-77), 60 (33 female) patients with suspected pulmonary hypertension (PH, age range 28-85)., Sequence: 2D spoiled gradient echo, 1.5T., Assessment: PA-PWV was measured from PREFUL-derived cardiac cycles based on the determination of temporal and spatial distance between lung vasculature voxels using a simplified (sPWV) method and a more comprehensive (cPWV) method including more elaborate distance calculation. For 135 individuals, PC MRI-based PWV (PWV-QA) was measured., Statistical Tests: Intraclass-correlation-coefficient (ICC) and coefficient of variation (CoV) were used to test repeatability. Nonparametric tests were used to compare cohorts. Correlation of sPWV/cPWV, PWV-QA, forced expiratory volume in 1 sec (FEV 1 ) %predicted, residual volume (RV) %predicted, age, and right heart catheterization (RHC) data were tested. Significance level α = 0.05 was used., Results: sPWV and cPWV showed no significant differences between repeated measurements (P-range 0.10-0.92). CoV was generally lower than 15%. COPD and PH patients had significantly higher sPWV and cPWV than healthy subjects. Significant correlation was found between sPWV or cPWV and FEV 1 %pred. (R = -0.36 and R = -0.44), but not with RHC (P-range -0.11 - 0.91) or age (P-range 0.23-0.89). Correlation to RV%pred. was significant for cPWV (R = 0.42) but not for sPWV (R = 0.34, P = 0.055). For all cohorts, sPWV and cPWV were significantly correlated with PWV-QA (R = -0.41 and R = 0.48)., Data Conclusion: PREFUL-derived PWV is feasible and repeatable. PWV is increased in COPD and PH patients and correlates to airway obstruction and hyperinflation., Level of Evidence: 3 TECHNICAL EFFICACY: Stage 2., (© 2024 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Objectives: To investigate potential presence and resolution of longer-term pulmonary diffusion limitation and microvascular perfusion impairment in COVID-19 convalescents., Materials and Methods: This prospective, longitudinal study was carried out between May 2020 and April 2023. COVID-19 convalescents repeatedly and age/sex-matched healthy controls once underwent MRI including hyperpolarized 129 Xe MRI. Blood samples were obtained in COVID-19 convalescents for immunophenotyping. Ratios of 129 Xe in red blood cells (RBC), tissue/plasma (TP), and gas phase (GP) as well as lung surface-volume ratio were quantified and correlations with CD4 + /CD8 + T cell frequencies were assessed using Pearson's correlation coefficient. Signed-rank tests were used for longitudinal and U tests for group comparisons., Results: Thirty-five participants were recruited. Twenty-three COVID-19 convalescents (age 52.1 ± 19.4 years, 13 men) underwent baseline MRI 12.6 ± 4.2 weeks after symptom onset. Fourteen COVID-19 convalescents underwent follow-up MRI and 12 were included for longitudinal comparison (baseline MRI at 11.5 ± 2.7 weeks and follow-up 38.0 ± 5.5 weeks). Twelve matched controls were included for comparison. In COVID-19 convalescents, RBC-TP was increased at follow-up (p = 0.04). Baseline RBC-TP was lower in patients treated on intensive care unit (p = 0.03) and in patients with severe/critical disease (p = 0.006). RBC-TP correlated with CD4 + /CD8 + T cell frequencies (R = 0.61/ - 0.60) at baseline. RBC-TP was not significantly different compared to matched controls at follow-up (p = 0.25)., Conclusion: Impaired microvascular pulmonary perfusion and alveolar membrane function persisted 12 weeks after symptom onset and resolved within 38 weeks after COVID-19 symptom onset., Clinical Relevance Statement: 129 Xe MRI shows improvement of microvascular pulmonary perfusion and alveolar membrane function between 11.5 ± 2.7 weeks and 38.0 ± 5.5 weeks after symptom onset in patients after COVID-19, returning to normal in subjects without significant prior disease., Key Points: • The study aims to investigate long-term effects of COVID-19 on lung function, in particular gas uptake efficiency, and on the cardiovascular system. • In COVID-19 convalescents, the ratio of 129 Xe in red blood cells/tissue plasma increased longitudinally (p = 0.04), but was not different from matched controls at follow-up (p = 0.25). • Microvascular pulmonary perfusion and alveolar membrane function are impaired 11.5 weeks after symptom onset in patients after COVID-19, returning to normal in subjects without significant prior disease at 38.0 weeks., (© 2024. The Author(s).)

Background: This study was a randomised, double-blind, placebo-controlled study intended to establish the translatability of the RLS-0071 mechanisms of action from animal disease models to humans by inhibiting neutrophil-mediated inflammation at the tissue level and major inflammatory biomarkers. We hypothesised that RLS-0071 inhibits a temporary neutrophil-mediated inflammation in the lungs induced by inhalation of low-dose lipopolysaccharide (LPS) in healthy participants., Methods: Participants were randomised to one of three arms to receive inhaled LPS followed by three doses of either low-dose (10 mg·kg -1 ) or high-dose (120 mg·kg -1 loading dose followed by two doses of 40 mg·kg -1 ) RLS-0071 i.v. or placebo (saline) every 8 h. Biomarkers evaluating inflammatory responses, with absolute neutrophil counts in induced sputum as the primary end-point, were collected before and at 6 and 24 h after LPS challenge., Results: Active treatment with RLS-0071 showed a similar safety profile to participants receiving placebo. RLS-0071 significantly decreased the numbers of neutrophils in sputum at 6 h post LPS by approximately half (p=0.04). Neutrophil effectors myeloperoxidase, neutrophil elastase and interleukin-1β in sputum were also significantly decreased at 6 h for RLS-0071 compared with placebo. Several biomarkers showed trends suggesting sustained decreases for RLS-0071 versus placebo at 24 h., Conclusion: This clinical trial demonstrated that RLS-0071 was safe and well tolerated and modulated neutrophil-mediated inflammation in humans after inhaled LPS challenge, consistent with results from prior animal model studies., Competing Interests: Conflict of interest: In accordance with our ethical obligation as researchers, we are reporting that J. Goss, P. Hair, U. Thienel and K. Cunnion are employed by ReAlta Life Sciences and receive funding in the form of salaries from ReAlta Life Sciences, a company that may be affected by the research reported in the enclosed paper. J.M. Hohlfeld reports grant support paid to his institution from AltamiraPharma GmbH, Astellas Pharma GmbH, AstraZeneca AB, Bayer AG, Beiersdorf AG, Boehringer Ingelheim Pharma GmbH & Co. KG, CSL Behring GmbH, Desitin Arzneimittel GmbH, EpiEndo Pharmaceuticals, F. Hoffmann-La Roche AG, Genentech, Inc., GlaxoSmithKline GmbH & Co. KG, Janssen Pharmaceutical NV, M&P Pharma AG, Novartis AG, ReAlta Life Sciences, Sanofi-Aventis Deutschland GmbH and UCB Pharma GmbH, personal fees for consultancy from Boehringer Ingelheim Pharma GmbH & Co. KG, Cureteq AG, Merck & Co, Inc., and Roche, personal fees for lectures from HAL Allergy Group and Novartis AG, and personal fees for board service from CSL Behring GmbH and Nocion. The remaining authors have nothing to disclose., (Copyright ©The authors 2024.)

Novel treatments are needed to reduce inflammation, improve symptoms, address exacerbations, and slow disease progression in bronchiectasis. Cathepsin C (CatC) inhibition promises to achieve this through reduction of neutrophil-derived serine protease (including neutrophil elastase [NE] and proteinase 3 [PR3]) activation. Here, we present the phase I characterization of the novel CatC inhibitor, BI 1291583. Five phase I trials of BI 1291583 in healthy subjects are presented: a single-rising-dose study (NCT03414008) and two multiple-rising-dose studies (NCT03868540 and NCT04866160) assessing the safety, tolerability, pharmacodynamics, and pharmacokinetics of BI 1291583; a food effect study (NCT03837964); and a drug-drug interaction study (NCT03890887) of BI 1291583 and itraconazole. BI 1291583 was safe and well tolerated across the doses tested in these trials. Most adverse events (AEs) were mild or moderate in intensity, with no serious AEs, AEs of special interest or deaths reported in any trial. Drug-related skin exfoliation was not reported more frequently in subjects treated with BI 1291583 compared with placebo. BI 1291583 was readily absorbed, and pharmacokinetics were supra-proportional over the dose ranges assessed. Additionally, BI 1291583 inhibited CatC in a dose-dependent manner, inhibited downstream NE activity, and decreased PR3 levels. No food effect was observed. Co-administration of multiple doses of itraconazole increased BI 1291583 exposure approximately twofold. Due to these promising phase I results, a multinational phase II program of BI 1291583 in adults with bronchiectasis is ongoing (Airleaf™ [NCT05238675], Clairafly™ [NCT05865886], and Clairleaf™ [NCT05846230])., (© 2024 Boehringer Ingelheim International GmbH and The Author(s). Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Objectives: 3D phase-resolved functional lung (PREFUL) MRI offers evaluation of pulmonary ventilation without inhalation of contrast agent. This study seeks to compare ventilation maps obtained from 3D PREFUL MRI with a direct ventilation measurement derived from 129 Xe MRI in both patients with chronic obstructive pulmonary disease (COPD) and healthy volunteers., Methods: Thirty-one patients with COPD and 12 healthy controls underwent free-breathing 3D PREFUL MRI and breath-hold 129 Xe MRI at 1.5 T. For both MRI techniques, ventilation defect (VD) maps were determined and respective ventilation defect percentage (VDP) values were computed. All parameters of both techniques were compared by Spearman correlation coefficient (r) and the differences between VDP values were quantified by Bland-Altman analysis and tested for significance using Wilcoxon signed-rank test. In a regional comparison of VD maps, spatial overlap and Sørensen-Dice coefficients of healthy and defect areas were computed., Results: On a global level, all 3D PREFUL VDP values correlated significantly to VDP measure derived by 129 Xe ventilation imaging (all r > 0.65; all p < 0.0001). 129 Xe VDP was significantly greater than 3D PREFUL derived VDP RVent (mean bias = 10.5%, p < 0.001) and VDP FVL-CM (mean bias = 11.3%, p < 0.0001) but not for VDP Combined (mean bias = 1.7%, p = 0.70). The total regional agreement of 129 Xe and 3D PREFUL VD maps ranged between 60% and 63%., Conclusions: Free-breathing 3D PREFUL MRI showed a strong correlation with breath-hold hyperpolarized 129 Xe MRI regarding the VDP values and modest differences in the detection of VDs on a regional level., Clinical Relevance Statement: 3D PREFUL MRI correlated with 129 Xe MRI, unveiling regional differences in COPD defect identification. This proposes 3D PREFUL MRI as a ventilation mapping surrogate, eliminating the need for extra hardware or inhaled gases., Key Points: Current non-invasive evaluation techniques for lung diseases have drawbacks; 129 Xe MRI is limited by cost and availability. 3D PREFUL MRI correlated with 129 Xe MRI, with regional differences in identifying COPD defects. 3D PREFUL MRI can provide ventilation mapping without the need for additional hardware or inhaled gases., (© 2024. The Author(s).)

Increased production of Prostaglandin D2 (PGD2) is linked to development and progression of asthma and allergy. PGD2 is rapidly degraded to its metabolites, which initiate type 2 innate lymphoid cells (ILC2) migration and IL-5/IL-13 cytokine secretion in a PGD2 receptor 2 (DP2)-dependent manner. Blockade of DP2 has shown therapeutic benefit in subsets of asthma patients. Cellular mechanisms of ILC2 activity in response to PGD2 and its metabolites are still unclear. We hypothesized that ILC2 respond non-uniformly to PGD2 metabolites. ILC2s were isolated from peripheral blood of patients with atopic asthma. ILC2s were stimulated with PGD2 and four PGD2 metabolites (Δ12-PGJ2, Δ12-PGD2, 15-deoxyΔ12,14-PGD2, 9α,11β-PGF2) with or without the selective DP2 antagonist fevipiprant. Total RNA was sequenced, and differentially expressed genes (DEG) were identified by DeSeq2. Differential gene expression analysis revealed an upregulation of pro-inflammatory DEGs in ILC2s stimulated with PGD2 (14 DEGs), Δ12-PGD2 (27 DEGs), 15-deoxyΔ12,14-PGD2 (56 DEGs) and Δ12-PGJ2 (136 DEGs), but not with 9α,11β-PGF2. Common upregulated DEGs were i.e. ARG2, SLC43A2, LAYN, IGFLR1, or EPHX2. Inhibition of DP2 via fevipiprant mainly resulted in downregulation of pro-inflammatory genes such as DUSP4, SPRED2, DUSP6, ETV1, ASB2, CD38, ADGRG1, DDIT4, TRPM2, or CD69. DEGs were related to migration and various immune response-relevant pathways such as "chemokine (C-C motif) ligand 4 production", "cell migration", "interleukin-13 production", "regulation of receptor signaling pathway via JAK-STAT", or "lymphocyte apoptotic process", underlining the pro-inflammatory effects of PGD2 metabolite-induced immune responses in ILC2s as well as the anti-inflammatory effects of DP2 inhibition via fevipiprant. Furthermore, PGD2 and metabolites showed distinct profiles in ILC2 activation. Overall, these results expand our understanding of DP2 initiated ILC2 activity., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Gress et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Quantitatively collecting and characterizing exhaled aerosols is vital for infection risk assessment, but the entire droplet size spectrum has often been neglected. We analyzed particle number and size distribution of healthy participants in various respiratory activities, considering inter-individual variability, and deployed a simplified far-field model to inform on infection risks. Methods: Participants repeated the same respiratory activities on two visits. Particles were collected using an airtight extraction helmet supplied with High Efficiency Particulate Air (HEPA) filtered air. The sampling volume flow was transported to two particle counters covering the small and large particle spectrum. The applied simple mass balance model included respiratory activity, viral load, room size, and air exchange rates. Results: Thirty participants completed the study. The major fraction of the number-based size distribution was <5 μm in all respiratory activities. In contrast, the major fraction of the volume-based size distribution was 2-12 μm in tidal breathing, but >60 μm in all other activities. Aerosol volume flow was lowest in tidal breathing, 10-fold higher in quiet/normal speaking, deep breathing, coughing, and 100-fold higher in loud speaking/singing. Intra-individual reproducibility was high. Between participants, aerosol volume flow varied by two orders of magnitude in droplets <80 μm, and three orders of magnitude in droplets >80 μm. Simple model calculations not accounting for potential particle size-dependent differences in viral load and infection-related differences were used to model airborne pathogen concentrations. Conclusions: Quantitative analysis of exhaled aerosols for the entire droplet size spectrum as well as the variability in aerosol emission between individuals provides information that can support infection research. Clinical Trial Registration number: NCT04771585.