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Abstract The human microbiome emerges as a promising reservoir for diagnostic markers and therapeutics. Since host-associated microbiomes at various body sites differ and diseases do not occur in isolation, a comprehensive analysis strategy highlighting the full potential of microbiomes should include diverse specimen types and various diseases. To ensure robust data quality and comparability across specimen types and diseases, we employ standardized protocols to generate sequencing data from 1931 prospectively collected specimens, including from saliva, plaque, skin, throat, eye, and stool, with an average sequencing depth of 5.3 gigabases. Collected from 515 patients, these samples yield an average of 3.7 metagenomes per patient. Our results suggest significant microbial variations across diseases and specimen types, including unexpected anatomical sites. We identify 583 unexplored species-level genome bins (SGBs) of which 189 are significantly disease-associated. Of note, the existence of microbial resistance genes in one specimen was indicative of the same resistance genes in other specimens of the same patient. Annotated and previously undescribed SGBs collectively harbor 28,315 potential biosynthetic gene clusters (BGCs), with 1050 significant correlations to diseases. Our combinatorial approach identifies distinct SGBs and BGCs, emphasizing the value of pan-body pan-disease microbiomics as a source for diagnostic and therapeutic strategies.

Abstract Background Patients with COPD are often affected by loss of bone mineral density (BMD) and osteoporotic fractures. Natriuretic peptides (NP) are known as cardiac markers, but have also been linked to fragility-associated fractures in the elderly. As their functions include regulation of fluid and mineral balance, they also might affect bone metabolism, particularly in systemic disorders such as COPD. Research question We investigated the association between NP serum levels, vertebral fractures and BMD assessed by chest computed tomography (CT) in patients with COPD. Methods Participants of the COSYCONET cohort with CT scans were included. Mean vertebral bone density on CT (BMD-CT) as a risk factor for osteoporosis was assessed at the level of TH12 (AI-Rad Companion), and vertebral compression fractures were visually quantified by two readers. Their relationship with N-terminal pro-B-type natriuretic peptide (NT-proBNP), Mid-regional pro-atrial natriuretic peptide (MRproANP) and Midregional pro-adrenomedullin (MRproADM) was determined using group comparisons and multivariable analyses. Results Among 418 participants (58% male, median age 64 years, FEV1 59.6% predicted), vertebral fractures in TH12 were found in 76 patients (18.1%). Compared to patients without fractures, these had elevated serum levels (p ≤ 0.005) of MRproANP and MRproADM. Using optimal cut-off values in multiple logistic regression analyses, MRproANP levels ≥ 65 nmol/l (OR 2.34; p = 0.011) and age (p = 0.009) were the only significant predictors of fractures after adjustment for sex, BMI, smoking status, FEV1% predicted, SGRQ Activity score, daily physical activity, oral corticosteroids, the diagnosis of cardiac disease, and renal impairment. Correspondingly, MRproANP (p

Abstract Objectives The implementation of the Lung Allocation Score (LAS) in the Eurotransplant international collaborative framework decreased waiting list mortality, but organ shortage remains a significant problem. Transplantation of two single lungs from one donor into two recipients (lung twinning) may decrease waiting list mortality. We sought to analyze if this strategy can lead to an acceptable intermediate-term outcome. Methods Since the LAS-implementation we performed 32 paired single-lung transplantations from 16 postmortal donors. Data and outcome were analyzed retrospectively comparing recipients receiving the first lung (first twins) with recipients receiving the second lung (second twins), left versus right transplantation and restrictive versus obstructive disease. Results Survival at one year was 81% and 54% at five years. Veno-venous ECMO had been successfully used as bridge-to-transplant in three patients with ECMO-explantation immediately after surgery. Bronchial anastomotic complications were not observed in any patient. First twins and second twins exhibited similar survival (p = 0.82) despite higher LAS in first twins (median 45 versus 34, p

Abstract Background Randomized controlled trials described beneficial effects of inhaled triple therapy (LABA/LAMA/ICS) in patients with chronic obstructive pulmonary disease (COPD) and high risk of exacerbations. We studied whether such effects were also detectable under continuous treatment in a retrospective observational setting. Methods Data from baseline and 18-month follow-up of the COPD cohort COSYCONET were used, including patients categorized as GOLD groups C/D at both visits (n = 258). Therapy groups were defined as triple therapy at both visits (triple always, TA) versus its complement (triple not always, TNA). Comparisons were performed via multiple regression analysis, propensity score matching and inverse probability weighting to adjust for differences between groups. For this purpose, variables were divided into predictors of therapy and outcomes. Results In total, 258 patients were eligible (TA: n = 162, TNA: n = 96). Without adjustments, TA patients showed significant (p

Abstract Chronic lung diseases such as chronic obstructive pulmonary disease and cystic fibrosis are incurable. Epithelial senescence, a state of dysfunctional cell cycle arrest, contributes to the progression of such diseases. Therefore, lung epithelial cells are a valuable target for therapeutic intervention. Here, we present a 3D airway lung organoid platform for the preclinical testing of active substances with regard to senescence, toxicity, and inflammation under standardized conditions in a 96 well format. Senescence was induced with doxorubicin and measured by activity of senescence associated galactosidase. Pharmaceutical compounds such as quercetin antagonized doxorubicin-induced senescence without compromising organoid integrity. Using single cell sequencing, we identified a subset of cells expressing senescence markers which was decreased by quercetin. Doxorubicin induced the expression of detoxification factors specifically in goblet cells independent of quercetin. In conclusion, our platform enables for the analysis of senescence-related processes and will allow the pre-selection of a wide range of compounds (e.g. natural products) in preclinical studies, thus reducing the need for animal testing.

Abstract Background Chronic obstructive pulmonary disease (COPD) is an inflammatory multisystemic disease caused by environmental exposures and/or genetic factors. Inherited alpha-1-antitrypsin deficiency (AATD) is one of the best recognized genetic factors increasing the risk for an early onset COPD with emphysema. The aim of this study was to gain a better understanding of the associations between comorbidities and specific biomarkers in COPD patients with and without AATD to enable future investigations aimed, for example, at identifying risk factors or improving care. Methods We focused on cardiovascular comorbidities, blood high sensitivity troponin (hs-troponin) and lipid profiles in COPD patients with and without AATD. We used clinical data from six German University Medical Centres of the MIRACUM (Medical Informatics Initiative in Research and Medicine) consortium. The codes for the international classification of diseases (ICD) were used for COPD as a main diagnosis and for comorbidities and blood laboratory data were obtained. Data analyses were based on the DataSHIELD framework. Results Out of 112,852 visits complete information was available for 43,057 COPD patients. According to our findings, 746 patients with AATD (1.73%) showed significantly lower total blood cholesterol levels and less cardiovascular comorbidities than non-AATD COPD patients. Moreover, after adjusting for the confounder factors, such as age, gender, and nicotine abuse, we confirmed that hs-troponin is a suitable predictor of overall mortality in COPD patients. The comorbidities associated with AATD in the current study differ from other studies, which may reflect geographic and population-based differences as well as the heterogeneous characteristics of AATD. Conclusion The concept of MIRACUM is suitable for the analysis of a large healthcare database. This study provided evidence that COPD patients with AATD have a lower cardiovascular risk and revealed that hs-troponin is a predictor for hospital mortality in individuals with COPD.

Abstract Background Alpha-1-antitrypsin deficiency (AATD) is a genetic disorder characterized by mutations in the SERPINA1 gene, primarily affecting the lungs and liver. The COVID-19 pandemic has raised questions about the susceptibility of individuals with AATD to COVID-19 and whether patients with rare lung disease might experience increased stress-related symptoms and mental health challenges. This study aims to investigate the impact of the COVID-19 pandemic on the quality of life of individuals living with AATD. Methods The study enrolled participants from the German registry for individuals with AATD. Questionnaires were sent to the 1250 participants, and a total of 358 patients were included in the analysis. The primary objective was to examine the influence of sociodemographic and disease-related factors on the occurrence of stress-related symptoms. This was accomplished through correlation and regression analyses. We also investigated the role of baseline quality of life (QoL), as measured by the St. George’s Respiratory Questionnaire (SGRQ), as a mediator of this relationship. Results Stress-related symptoms were predicted by young age, female gender, psychological disorders, and a history of exacerbations of lung disease, as determined by multiple regression analysis. QoL as measured by the SGRQ mediated the relationship between poor lung function, stress, and a decline in overall well-being. Conclusion The presented data demonstrate that the COVID-19 pandemic significantly affects the psychological well-being of patients with rare diseases, leading to increased levels of anxiety and stress. Disease-related factors can exacerbate stress manifestations, especially when compounded by sociodemographic and contextual factors. Thus, our study emphasizes the crucial role of taking these factors into account when managing individuals with AATD in pandemic situations.

Capnocytophaga canimorsus is a rare cause of serious infections with a high mortality of 10% to 30%. It is usually found in the oral cavity of cats and dogs and can cause severe sepsis in immunocompromised patients. An 81-year-old female Caucasian patient presented with C. canimorsus sepsis after a dog bite in her finger three days before presentation to our emergency department. She initially was presented to us with sepsis, thrombopenia, and schistocytes in her laboratory findings, suggesting the differential diagnoses of the multiple subtypes of thrombotic microangiopathy. She was admitted to the medical intensive care unit of the University Hospital of Saarland because of septic shock with circulatory insufficiency. The patient received plasmapheresis, antibiotics, and dialysis, under which she improved significantly. The fingertip of the affected finger developed necrosis and had to be amputated. Furthermore, the patient was diagnosed with a mitral valve endocarditis, a very rare complication of C. canimorsus infection. It was treated conservatively with antibiotics and was no longer detectable 8 weeks after the diagnosis. Surgical intervention was not needed. The case describes well that it is still difficult to distinguish between thrombotic thrombocytopenic purpura (TTP), disseminated intravascular coagulation (DIC), and sepsis-induced coagulopathy (SIC), especially in the early phases of acute disease, especially in C. canimorsus-induced sepsis.

Background: The use of maintenance medication in patients with chronic obstructive pulmonary disease (COPD) in real life is known to deviate from recommendations in guidelines, which are largely based on randomized controlled trials and selected populations. Objectives: We used the COSYCONET ( CO PD and Sy stemic Consequences – Co morbidities Net work) cohort to analyze factors linked to the use of COPD drugs under non-interventional circumstances. Design: COSYCONET is an ongoing, multi-center, non-interventional cohort of patients with COPD. Methods: Patients with COPD of Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 0–4 participating in visits 1–5 were included. Data covered the period from 2010 to 2018. Generalized linear models were used to examine the relation of COPD characteristics to different types of respiratory medication. Results: A total of 1043 patients were included. The duration of observation was 4.5 years. Use of respiratory medication depended on GOLD grades 0–4 and groups A-D. Long-acting muscarinic antagonist therapy increased over time, and was associated with low carbon monoxide (CO) diffusing capacity, while inhaled corticosteroid (ICS) use decreased. Active smoking was associated with less maintenance therapy in general, and female sex with less ICS use. From the eight items of the COPD Assessment Test, only hill and stair climbing were consistently linked to treatment. Conclusion: Using data from a large, close to real-life observational cohort, we identified factors linked to the use of various types of respiratory COPD medication. Overall, use was consistent with GOLD recommendations. Beyond this, we identified other correlates of medication use that may help us to understand and improve therapy decisions in clinical practice. Trial registration: ClinicalTrials.gov NCT01245933.

Abstract In chronic obstructive pulmonary disease (COPD), comorbidities and worse functional status predict worse outcomes, but how these predictors compare with regard to different outcomes is not well studied. We thus compared the role of cardiovascular comorbidities for mortality and exacerbations. Data from baseline and up to four follow-up visits of the COSYCONET cohort were used. Cox or Poisson regression was employed to determine the relationship of predictors to mortality or mean annual exacerbation rate, respectively. Predictors comprised major comorbidities (including cardiovascular disease), lung function (forced expiratory volume in 1 s [FEV1], diffusion capacity for carbon monoxide [TLCO]) and their changes over time, baseline symptoms, exacerbations, physical activity, and cardiovascular medication. Overall, 1817 patients were included. Chronic coronary artery disease (p = 0.005), hypertension (p = 0.044) and the annual decline in TLCO (p = 0.001), but not FEV1 decline, were predictors of mortality. In contrast, the annual decline of FEV1 (p = 0.019) but not that of TLCO or cardiovascular comorbidities were linked to annual exacerbation rate. In conclusion, the presence of chronic coronary artery disease and hypertension were predictors of increased mortality in COPD, but not of increased exacerbation risk. This emphasizes the need for broad diagnostic workup in COPD, including the assessment of cardiovascular comorbidity. Clinical Trials: NCT01245933.

ABSTRACT: Background: Early prognostication of COVID-19 severity will potentially improve patient care. Biomarkers, such as TNF-related apoptosis-inducing ligand (TRAIL), interferon gamma-induced protein 10 (IP-10), and C-reactive protein (CRP), might represent possible tools for point-of-care testing and severity prediction. Methods: In this prospective cohort study, we analyzed serum levels of TRAIL, IP-10, and CRP in patients with COVID-19, compared them with control subjects, and investigated the association with disease severity. Results: A total of 899 measurements were performed in 132 patients (mean age 64 years, 40.2% females). Among patients with COVID-19, TRAIL levels were lower (49.5 vs 87 pg/ml, P = 0.0142), whereas IP-10 and CRP showed higher levels (667.5 vs 127 pg/ml, P

Abstract In patients with COPD, it has not been comprehensively assessed whether the predictive value of comorbidities for mortality differs between men and women. We therefore aimed to examine sex differences of COPD comorbidities in regard with prognosis by classifying comorbidities into a comorbidome related to extrapulmonary disorders and a pulmorbidome, referring to pulmonary disorders. The study population comprised 1044 women and 1531 men with the diagnosis of COPD from COSYCONET, among them 2175 of GOLD grades 1–4 and 400 at risk. Associations of comorbidities with mortality were studied using Cox regression analysis for men and women separately. During the follow-up (median 3.7 years) 59 women and 159 men died. In men, obesity, hypertension, coronary artery disease, liver cirrhosis, osteoporosis, kidney disease, anaemia and increased heart rate (HR) predict mortality, in women heart failure, hyperuricemia, mental disorders, kidney disease and increased HR (p

High-quality DNA extraction is a crucial step in metagenomic studies. Bias by different isolation kits impairs the comparison across datasets. A trending topic is, however, the analysis of multiple metagenomes from the same patients to draw a holistic picture of microbiota associated with diseases. We thus collected bile, stool, saliva, plaque, sputum, and conjunctival swab samples and performed DNA extraction with three commercial kits. For each combination of the specimen type and DNA extraction kit, 20-gigabase (Gb) metagenomic data were generated using short-read sequencing. While profiles of the specimen types showed close proximity to each other, we observed notable differences in the alpha diversity and composition of the microbiota depending on the DNA extraction kits. No kit outperformed all selected kits on every specimen. We reached consistently good results using the Qiagen QiAamp DNA Microbiome Kit. Depending on the specimen, our data indicate that over 10 Gb of sequencing data are required to achieve sufficient resolution, but DNA-based identification is superior to identification by mass spectrometry. Finally, long-read nanopore sequencing confirmed the results (correlation coefficient > 0.98). Our results thus suggest using a strategy with only one kit for studies aiming for a direct comparison of multiple microbiotas from the same patients.

Extracorporeal membrane oxygenation (ECMO) is an important rescue therapy method for the treatment of severe hypoxic lung injury. In some cases, oxygen saturation and oxygen partial pressure in the arterial blood are low despite ECMO therapy. There are case reports in which patients with such instances of refractory hypoxemia received a second membrane lung, either in series or in parallel, to overcome the hypoxemia. It remains unclear whether the parallel or serial connection is more effective. Therefore, we used an improved version of our full-flow ECMO mock circuit to test this. The measurements were performed under conditions in which the membrane lungs were unable to completely oxygenate the blood. As a result, only the photometric pre- and post-oxygenator saturations, blood flow and hemoglobin concentration were required for the calculation of oxygen transfer rates. The results showed that for a pre-oxygenator saturation of 45% and a total blood flow of 10 L/min, the serial connection of two identical 5 L rated oxygenators is 17% more effective in terms of oxygen transfer than the parallel connection. Although the idea of using a second membrane lung if refractory hypoxia occurs is intriguing from a physiological point of view, due to the invasiveness of the solution, further investigations are needed before this should be used in a wider clinical setting.

Abstract Background Both allergen-specific IgE and total IgE in serum play a major role in asthma. However, the role of IgE in chronic obstructive pulmonary disease (COPD) is poorly understood. It was the aim of this study to systematically analyze the relationship between serum IgE levels and disease characteristics in large COPD cohorts. Methods COSYCONET is a comprehensively characterized cohort of patients with COPD: total IgE and IgE specific to common aeroallergens were measured in serum of 2280 patients, and related to clinical characteristics of the patients. WISDOM is another large COPD population (2477 patients): this database contains the information whether total IgE in serum was elevated (≥ 100 IU/l) or normal in patients with COPD. Results Both in COSYCONET and WISDOM, total IgE was elevated (≥ 100 IU/l) in > 30% of the patients, higher in men than in women, and higher in currently than in not currently smoking men. In COSYCONET, total IgE was elevated in patients with a history of asthma and/or allergies. Men with at least one exacerbation in the last 12 months (50.6% of all men in COSYCONET) had higher median total IgE (71.3 IU/l) than men without exacerbations (48.3 IU/l): this difference was also observed in the subgroups of not currently smoking men and of men without a history of asthma. Surprisingly, a history of exacerbations did not impact on total IgE in women with COPD. Patients in the highest tertiles of total IgE (> 91.5 IU/ml, adjusted OR: 1.62, 95% CI 1.12–2.34) or allergen-specific IgE (> 0.19 IU/ml, adjusted OR: 2.15, 95% CI 1.32–3.51) were at risk of lung function decline (adjusted by: age, gender, body mass index, initial lung function, smoking status, history of asthma, history of allergy). Conclusion These data suggest that IgE may play a role in specific COPD subgroups. Clinical trials using antibodies targeting the IgE pathway (such as omalizumab), especially in men with recurrent exacerbations and elevated serum IgE, could elucidate potential therapeutic implications of our observations.

Abstract We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1–4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV1, FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p

Background: Chest computed tomography (CT) is increasingly used for phenotyping and monitoring of patients with COPD. The aim of this work was to evaluate the association of Pi10 as a measure of standardized airway wall thickness on CT with exacerbations, mortality, and response to triple therapy. Methods: Patients of GOLD grades 1–4 of the COSYCONET cohort with prospective CT scans were included. Pi10 was automatically computed and analyzed for its relationship to COPD severity, comorbidities, lung function, respiratory therapy, and mortality over a 6-year period, using univariate and multivariate comparisons. Results: We included n = 433 patients (61%male). Pi10 was dependent on both GOLD grades 1–4 ( p = 0.009) and GOLD groups A–D ( p = 0.008); it was particularly elevated in group D, and ROC analysis yielded a cut-off of 0.26 cm. Higher Pi10 was associated to lower FEV 1 % predicted and higher RV/TLC, moreover the annual changes of lung function parameters ( p

As a consequence of the continued Covid-19 lockdown in Germany, in-hospital teaching for medical students was impossible. While lectures and other theoretical training were relatively easily converted into online sessions using platforms such as Moodle, Zoom and Microsoft Teams, this was not the case for practical skills and clinical interventions, such as bronchoscopy or colonoscopy. This study describes a workaround that was implemented at the Saarland University Hospital utilizing virtual reality equipment to convey the impressions of shadowing clinical procedures to the students without physical presence. To achieve this, 3D 180° videos of key clinical interventions of various internal medicine specialities were recorded, cut, and censored. The videos were uploaded to the e-learning YouTube channel of our institution and shared with the students via the private share function. The students could choose whether to use a VR-viewer to watch the videos immersively or to watch them without a viewer on a screen non-immersively. At the end of the course after 1 week, the students completed a questionnaire anonymously focusing on learning-success regarding the presented topics, a self-assessment, and an evaluation of the course. A total of 27 students watched the videos with a VR-Viewer and 74 watched non-immersively. Although the VR-viewer group self-assessed their expertise higher, there was no significant difference between the two groups in the learning-success test score. However, students in the VR-viewer group rated the learning atmosphere, comprehensibility, and overall recommendation of the course significantly higher. They also agreed significantly more to the statement, that they gained a better conception of the presented procedures, and that virtual reality might be an appropriate tool for online teaching. Video-assisted teaching facilitates learning and might be a valuable add-on to conventional teaching.Abbreviations: Covid-19: severe acute respiratory syndrome coronavirus 2; 3D: three-dimensional; 2D: Two-dimensional; VR: virtual reality

Abstract Background Despite numerous advances in the identification of risk factors for the development of severe coronavirus disease 2019 (COVID-19), factors that promote recovery from COVID-19 remain unknown. Natural killer (NK) cells provide innate immune defense against viral infections and are known to be activated during moderate and severe COVID-19. Killer immunoglobulin-like receptors (KIR) mediate NK cell cytotoxicity through recognition of an altered MHC-I expression on infected target cells. However, the influence of KIR genotype on outcome of patients with COVID-19 has not been investigated so far. We retrospectively analyzed the outcome associations of NK cell count and KIR genotype of patients with COVID-19 related severe ARDS treated on our tertiary intensive care unit (ICU) between February and June 2020 and validated our findings in an independent validation cohort of patients with moderate COVID-19 admitted to our tertiary medical center. Results Median age of all patients in the discovery cohort (n = 16) was 61 years (range 50–71 years). All patients received invasive mechanical ventilation; 11 patients (68%) required extracorporeal membrane oxygenation (ECMO). Patients who recovered from COVID-19 had significantly higher median NK cell counts during the whole observational period compared to patients who died (121 cells/µL, range 16–602 cells/µL vs 81 cells/µL, range 6–227 cells/µL, p-value = 0.01). KIR2DS5 positivity was significantly associated with shorter time to recovery (21.6 ± 2.8 days vs. 44.6 ± 2.2 days, p-value = 0.01). KIR2DS5 positivity was significantly associated with freedom from transfer to ICU (0% vs 9%, p-value = 0.04) in the validation cohort which consisted of 65 patients with moderate COVID-19. Conclusion NK cells and KIR genotype might have an impact on recovery from COVID-19.

Abstract Background Lung emphysema is an important phenotype of chronic obstructive pulmonary disease (COPD), and CT scanning is strongly recommended to establish the diagnosis. This study aimed to identify criteria by which physicians with limited technical resources can improve the diagnosis of emphysema. Methods We studied 436 COPD patients with prospective CT scans from the COSYCONET cohort. All items of the COPD Assessment Test (CAT) and the St George’s Respiratory Questionnaire (SGRQ), the modified Medical Research Council (mMRC) scale, as well as data from spirometry and CO diffusing capacity, were used to construct binary decision trees. The importance of parameters was checked by the Random Forest and AdaBoost machine learning algorithms. Results When relying on questionnaires only, items CAT 1 & 7 and SGRQ 8 & 12 sub-item 3 were most important for the emphysema- versus airway-dominated phenotype, and among the spirometric measures FEV1/FVC. The combination of CAT item 1 (≤ 2) with mMRC (> 1) and FEV1/FVC, could raise the odds for emphysema by factor 7.7. About 50% of patients showed combinations of values that did not markedly alter the likelihood for the phenotypes, and these could be easily identified in the trees. Inclusion of CO diffusing capacity revealed the transfer coefficient as dominant measure. The results of machine learning were consistent with those of the single trees. Conclusions Selected items (cough, sleep, breathlessness, chest condition, slow walking) from comprehensive COPD questionnaires in combination with FEV1/FVC could raise or lower the likelihood for lung emphysema in patients with COPD. The simple, parsimonious approach proposed by us might help if diagnostic resources regarding respiratory diseases are limited. Trial registration ClinicalTrials.gov, Identifier: NCT01245933, registered 18 November 2010, https://clinicaltrials.gov/ct2/show/record/NCT01245933 .

Abstract We hypothesized that the scarcity of N-nucleotides might contribute to the inability of the neonate to mount a robust allergic immune response. To test this, we used terminal deoxyribunucleotidyl Transferase deficient (TdT−/−) mice, which express “fetal-like” T cell receptor and immunoglobulin repertoires with largely germline-encoded CDR3 regions. Intraperitoneal sensitization was followed by aerosol provocation with either PBS or the allergen OVA in both TdT−/− mice and wild-type mice to develop allergic respiratory inflammation. The effects of this procedure were investigated by lung function test, immunological analysis of serum and brochoalveolar lavage. The local TH2 cytokine milieu was significantly attenuated in TdT−/− mice. Within this group, the induction of total IgE levels was also significantly reduced after sensitization. TdT−/− mice showed a tendency toward reduced eosinophilic inflow into the bronchial tubes, which was associated with the elimination of respiratory hyperreactivity. In conclusion, in a murine model of allergic airway inflammation, the expression of fetal-like antigen receptors was associated with potent indications of a reduced ability to mount an asthma phenotype. This underlines the importance of somatically-generated antigen-receptor repertoire diversity in type one allergic immune responses and suggests that the fetus may be protected from allergic responses, at least in part, by controlling N addition.

Constant exposure of the airways to inhaled pathogens requires efficient early immune responses protecting against infections. How bacteria on the epithelial surface are detected and first-line protective mechanisms are initiated are not well understood. We have recently shown that tracheal brush cells (BCs) express functional taste receptors. Here we report that bitter taste signaling in murine BCs induces neurogenic inflammation. We demonstrate that BC signaling stimulates adjacent sensory nerve endings in the trachea to release the neuropeptides CGRP and substance P that mediate plasma extravasation, neutrophil recruitment, and diapedesis. Moreover, we show that bitter tasting quorum-sensing molecules from Pseudomonas aeruginosa activate tracheal BCs. BC signaling depends on the key taste transduction gene Trpm5, triggers secretion of immune mediators, among them the most abundant member of the complement system, and is needed to combat P. aeruginosa infections. Our data provide functional insight into first-line defense mechanisms against bacterial infections of the lung.

Background: For translational research on lung diseases it is desirable to have human organoids which resemble features of human tissue. Adult stem cells obtained from human bronchial epithelium can be differentiated to little tissue follicles, so-called bronchospheres. Aim of the study was to characterize structural details of bronchospheres treated with control media, lipopolysaccharide, and flagellin during the differentiation phase. Basic procedures: Human bronchial epithelial stem cells were prepared from surgical specimens and differentiated in Matrigel to bronchospheres. Histology and transmission electron microscopy revealed the cellular structure of the bronchospheres. Main findings: Follicles with a diameter of about 120 µm were confined by a bilayered epithelium with surface differentiation towards the inner lumen of the follicle and junctional complexes. Microvilli, kinocilia as well as secretory cells were found. Treatment with the bacterial flagellin resulted in the formation of secretory granules and inhibited the occurrence of kinocilia. Principal conclusions: Despite clear limitations such as lacking of smooth muscles and columnar epithelium human bronchospheres are an interesting tool for translational research. They can be useful for studies addressing developmental processes, infections, drug testing and toxicology.

Abstract Background Extracorporeal carbon dioxide removal (ECCO2R) is a promising yet limited researched therapy for hypercapnic respiratory failure in acute respiratory distress syndrome and exacerbated chronic obstructive pulmonary disease. Herein, we describe a new mock circuit that enables experimental ECCO2R research without animal models. In a second step, we use this model to investigate three experimental scenarios of ECCO2R: (I) the influence of hemoglobin concentration on CO2 removal. (II) a potentially portable ECCO2R that uses air instead of oxygen, (III) a low-flow ECCO2R that achieves effective CO2 clearance by recirculation and acidification of the limited blood volume of a small dual lumen cannula (such as a dialysis catheter). Results With the presented ECCO2R mock, CO2 removal rates comparable to previous studies were obtained. The mock works with either fresh porcine blood or diluted expired human packed red blood cells. However, fresh porcine blood was preferred because of better handling and availability. In the second step of this work, hemoglobin concentration was identified as an important factor for CO2 removal. In the second scenario, an air-driven ECCO2R setup showed only a slightly lower CO2 wash-out than the same setup with pure oxygen as sweep gas. In the last scenario, the low-flow ECCO2R, the blood flow at the test membrane lung was successfully raised with a recirculation channel without the need to increase cannula flow. Low recirculation ratios resulted in increased efficiency, while high recirculation ratios caused slightly reduced CO2 removal rates. Acidification of the CO2 depleted blood in the recirculation channel caused an increase in CO2 removal rate. Conclusions We demonstrate a simple and cost effective, yet powerful, “in-vitro” ECCO2R model that can be used as an alternative to animal experiments for many research scenarios. Moreover, in our approach parameters such as hemoglobin level can be modified more easily than in animal models.

Abstract Cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) are associated with acute and chronic bacterial infections of the lung. Excessive differentiation of basal cells to mucus-producing goblet cells can result in mucus hyperproduction and loss of mucociliary clearance in the airways of CF and COPD patients. Here, we aimed to investigate the effect of pathogen-associated molecular patterns (PAMPs) on the differentiation of human 3D bronchospheres. Primary human bronchial epithelial cells (HBECs) were differentiated to bronchospheres in the presence of bacterial flagellin and LPS and the synthetic Toll-like receptor (TLR) ligands Pam3CSK4 (TLR-2) and polyinosinic:polycytidylic acid (pIC, TLR-3). Electron and fluorescence microscopy showed that the differentiation of bronchospheres associated with the formation of lumina and appearance of cilia within 30 days after seeding. Incubation with flagellin resulted in a decreased formation of lumina and loss of cilia formation. Incubation with Pam3CSK, pIC, and LPS did not significantly affect formation of lumina and ciliation. Mucus production was strongly increased in response to flagellin and, to a lesser degree, in response to Pam3CSK4. Our results indicate that bacterial factors, such as flagellin, drive the differentiation of the respiratory epithelium towards mucus hyperproduction.

Abstract Background The interleukin 17 receptor E (IL-17RE) is specific for the epithelial cytokine interleukin-17C (IL-17C). Asthma exacerbations are frequently caused by viral infections. Polyinosinic:polycytidylic acid (pIC) mimics viral infections through binding to pattern recognition receptors (e.g. TLR-3). We and others have shown that pIC induces the expression of IL-17C in airway epithelial cells. Using different mouse models, we aimed to investigate the function of IL-17RE in the development of experimental allergic asthma and acute exacerbation thereof. Methods Wild-type (WT) and IL-17RE deficient (Il-17re −/− ) mice were sensitized and challenged with OVA to induce allergic airway inflammation. pIC or PBS were applied intranasally when allergic airway inflammation had been established. Pulmonary expression of inflammatory mediators, numbers of inflammatory cells, and airway hyperresponsiveness (AHR) were analyzed. Results Ablation of IL-17RE did not affect the development of OVA-induced allergic airway inflammation and AHR. pIC induced inflammation independent of IL-17RE in the absence of allergic airway inflammation. Treatment of mice with pIC exacerbated pulmonary inflammation in sensitized and OVA-challenged mice in an IL-17RE-dependent manner. The pIC-induced expression of cytokines (e.g. keratinocyte-derived chemokine (KC), granulocyte-colony stimulating factor (G-CSF)) and recruitment of neutrophils were decreased in Il-17re −/− mice. pIC-exacerbated AHR was partially decreased in Il-17re −/− mice. Conclusions Our results indicate that IL-17RE mediates virus-triggered exacerbations but does not have a function in the development of allergic lung disease.

Abstract Background Titanium dioxide nanoparticles (TiO2 NPs) have a wide range of applications in several industrial and biomedical domains. Based on the evidence, the workers exposed to inhaled nanosized TiO2 powder are more susceptible to the risks of developing respiratory diseases. Accordingly, this issue has increasingly attracted the researchers’ interest in understanding the consequences of TiO2 NPs exposure. Regarding this, the present study was conducted to analyze the local effects of TiO2 NPs on allergic airway inflammation and their uptake in a mouse model of ovalbumin (OVA)-induced allergic airway inflammation. Methods For the purpose of the study, female BALB/c mice with or without asthma were intranasally administered with TiO2 NPs. The mice were subjected to histological assessment, lung function testing, scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and NP uptake measurement. In addition, T helper (Th) 1/Th2 cytokines were evaluated in the lung homogenate using the enzyme-linked immunosorbent assay. Results According to the results, the mice receiving OVA alone or OVA plus TiO2 NPs showed eosinophilic infiltrates and mucus overproduction in the lung tissues, compared to the controls. Furthermore, a significant elevation was observed in the circulating Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13 after NP exposure. The TiO2 NPs were taken up by alveolar macrophages at different time points. As the results of the SEM and ICP-MS indicated, TiO2 NPs were present in most of the organs in both asthmatic and non-asthmatic mice. Conclusion Based on the findings of the current study, intranasally or inhalation exposure to high-dose nanosized TiO2 particles appears to exacerbate the allergic airway inflammation and lead to systemic uptake in extrapulmonary organs. These results indicate the very important need to investigate the upper limit of intranasally or inhalation exposure to nanosized TiO2 particles in occupational and environmental health policy.

Abstract Background The use of electronic cigarettes (ECIGs) is increasing, but the impact of ECIG-vapor on cellular processes like inflammation or host defense are less understood. The aim of the present study was to compare the acute effects of traditional cigarettes (TCIGs) and ECIG-exposure on host defense, inflammation, and cellular activation of cell lines and primary differentiated human airway epithelial cells (pHBE). Methods We exposed pHBEs and several cell lines to TCIG-smoke or ECIG-vapor. Epithelial host defense and barrier integrity were determined. The transcriptome of airway epithelial cells was compared by gene expression array analysis. Gene interaction networks were constructed and differential gene expression over all groups analyzed. The expression of several candidate genes was validated by qRT-PCR. Results Bacterial killing, barrier integrity and the expression of antimicrobial peptides were not affected by ECIG-vapor compared to control samples. In contrast, TCIGs negatively affected host defense and reduced barrier integrity in a significant way. Furthermore ECIG-exposure significantly induced IL-8 secretion from Calu-3 cells but had no effect on NCI-H292 or primary cells. The gene expression based on array analysis distinguished TCIG-exposed cells from ECIG and room air-exposed samples. Conclusion The transcriptome patterns of host defense and inflammatory genes are significantly distinct between ECIG-exposed and TCIG-treated cells. The overall effects of ECIGs on epithelial cells are less in comparison to TCIG, and ECIG-vapor does not affect host defense. Nevertheless, although acute exposure to ECIG-vapor induces inflammation, and the expression of S100 proteins, long term in vivo data is needed to evaluate the chronic effects of ECIG use.

Long COVID is a collection of symptoms as a late sequelae of SARS-CoV-2 infection. It often includes mental symptoms such as cognitive symptoms, persisting loss of smell and taste, in addition to exertional dyspnea. A role of various autoantibodies (autoAbs) has been postulated in long-COVID and is being further investigated. With the goal of identifying potentially unknown autoAbs, we screened plasma of patients with long COVID on in-house post-translationally modified protein macroarrays including citrullinated, SUMOylated and acetylated membranes. SUMO1ylated isoform DEAD/H (Asp-Glu-Ala-Asp/His) box helicase 35 (SUMO1-DHX35) was identified as only candidate antigen. In adult patients with long COVID, IgG autoAbs against SUMO1-DHX35 of IgG class were found in seven of 71 (9.8%) plasma samples, of IgM and IgG class in one of 69 (1.4%) samples, not in 200 healthy adult controls, not in 442 healthy children, and 146 children after SARS-CoV-2 infection. All autoAb-positive seven patients were female. AutoAb titers ranged between 200 to up to 400 By point mutagenesis and expression of FLAG-tagged mutants of DHX35 in HEK293 cells, and subsequent SUMOylation of purified constructs, lysine 53 was identified as a unique, never yet identified, SUMOylation site. The autoAbs had no reactivity against the non-SUMO1ylated mutant (K53R) of DHX35. To summarize, autoAbs against SUMO1-DHX35 were identified in adult female patients with long-COVID. Further studies are needed to verify the frequency of occurrence. The function of DHX35 has not yet been determined and there is no available information in relation to disease implication. The molecular mechanism causing the SUMOylation, the potential functional consequences of this post-translational modification on DHX35, and a potential pathogenicity of the autoAbs against SUMO1-DHX35 in COVID-19 and other possible contexts remain to be elucidated.

BackgroundGlycyrrhizin, an active component of liquorice root extract, exhibits antiviral and immunomodulatory properties by direct inhibition of the pro-inflammatory alarmin HMGB1 (High-mobility group box 1).ObjectiveThe aim of this study was to explore the role of liquorice intake on the viral entry receptor ACE2 (angiotensin-converting enzyme 2) and the immunoregulatory HMGB1 in healthy individuals and to explore HMGB1 expression in coronavirus disease 2019 (COVID-19) or non-COVID-19 in ARDS (acute respiratory distress syndrome patients).Material and methodsThis study enrolled 43 individuals, including hospitalised patients with i) acute respiratory distress syndrome (ARDS) due to COVID-19 (n = 7) or other underlying causes (n = 12), ii) mild COVID-19 (n = 4) and iii) healthy volunteers (n = 20). Healthy individuals took 50 g of liquorice (containing 3% liquorice root extract) daily for 7 days, while blood samples were collected at baseline and on day 3 and 7. Changes in ACE2 and HMGB1 levels were determined by Western blot analysis and enzyme-linked immunosorbent assay, respectively. Additionally, HMGB1 levels were measured in hospitalised COVID-19 patients with mild disease or COVID-19 associated acute respiratory distress syndrome (ARDS) and compared with a non-COVID-19-ARDS group.ResultsLiquorice intake significantly reduced after 7 days both cellular membranous ACE2 expression (-51% compared to baseline levels, p = 0.008) and plasma HMGB1 levels (-17% compared to baseline levels, pConclusionsLiquorice intake modulates ACE2 and HMGB1 levels in healthy individuals. HMGB1 is enhanced in mild COVID-19 and in ARDS with and without COVID-19, warranting evaluation of HMGB1 as a potential treatment target and glycyrrhizin, which is an active component of liquorice root extract, as a potential treatment in COVID-19 and non-COVID-19 respiratory disease.

Pneumonia is a common cause of morbidity and mortality and is most often caused by bacterial pathogens. COVID-19 is characterized by lung infection with potential progressive organ failure. The systemic consequences of both disease on the systemic blood metabolome are not fully understood. The aim of this study was to compare the blood metabolome of both diseases and we hypothesize that plasma metabolomics may help to identify the systemic effects of these diseases. Therefore, we profiled the plasma metabolome of 43 cases of COVID-19 pneumonia, 23 cases of non-COVID-19 pneumonia, and 26 controls using a non-targeted approach. Metabolic alterations differentiating the three groups were detected, with specific metabolic changes distinguishing the two types of pneumonia groups. A comparison of venous and arterial blood plasma samples from the same subjects revealed the distinct metabolic effects of pulmonary pneumonia. In addition, a machine learning signature of four metabolites was predictive of the disease outcome of COVID-19 subjects with an area under the curve (AUC) of 86 ± 10%. Overall, the results of this study uncover systemic metabolic changes that could be linked to the etiology of COVID-19 pneumonia and non-COVID-19 pneumonia.

Background: Infection control measures for coronavirus disease 2019 (COVID-19) might have affected management and clinical state of patients with COPD. We analysed to which extent this common notion is fact-based. Methods: Patients of the COSYCONET cohort were contacted with three recurring surveys (COVID1, 2 and 3 at 0, 3 and 6 months, respectively). The questionnaires comprised behaviour, clinical and functional state, and medical treatment. The responses to the questionnaires were compared amongst themselves and with pre-COVID information from the last visit of COSYCONET. Results: Overall, 594 patients were contacted and 375 patients (58% males, forced expiratory volume in 1 s (FEV1) 61±22% predicted) provided valid data in COVID1 and COVID2. Five patients reported infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most patients – except for patients with higher education – reported compliance with recommended protective measures, whereby compliance to hygiene, contact and access to physicians slightly improved between COVID1 and COVID2. Also, patients obtained more information from physicians than from public media. In the majority of cases, the personal physician could not be substituted by remote consultation. Over time, symptoms slightly increased and self-assessed physical capacity decreased. Results of COVID3 were similar. Women and patients with more exacerbations and dyspnoea avoided medical consultations, whereas Global Initiative for Chronic Obstructive Lung Disease (GOLD) D patients were more amenable to tele-consultation. Conclusion: In well-characterised COPD patients, we observed on average slight deteriorations of clinical state during the period of COVID-19 restrictions, with high and partially increasing adherence to protective measures. The data suggest that in particular, women and GOLD D patients should be actively contacted by physicians to identify deteriorations.

Background Patients with ZZ (Glu342Lys) α-1-antitrypsin deficiency (ZZ-AATD) who received augmentation therapy with α-1-antitrypsin (AAT) in randomised controlled trials over 2–3 years failed to show a significant reduction of the annual decline of forced expiratory volume in 1 s (FEV1). Methods To compare the trajectory of FEV1 change during 4 or more years in ZZ-AATD patients with emphysema receiving or not receiving intravenous augmentation therapy, a retrospective analysis of FEV1 values entered in the Alpha-1 International Registry (AIR) of ZZ-AATD patients from five different European countries (Germany, UK, Spain, Italy and the Netherlands) was performed. The post-bronchodilator FEV1 % predicted values for baseline and follow-up over time from patients were analysed using linear mixed effects models. Results Data of 374 patients were analysed: 246 untreated and 128 treated with intravenous AAT augmentation therapy. The mean±sd follow-up duration of the untreated group was 8.60±3.34 years and 8.59±2.62 years for the treated group. The mixed effects model analysis showed a mean FEV1 decline of −0.931% predicted per year (95% CI −1.144 to −0.718) in the untreated group and a decline of −1.016% predicted per year (95% CI −1.319 to −0.7145) in the treated group. The likelihood ratio test showed no difference between the two groups (p=0.71). Conclusion In our study population, we could not detect a significant difference in the annual decline of FEV1 by AAT augmentation treatment over a mean period of 8.6 years. Other approaches are needed to validate any benefit of augmentation therapy.

Abstract Pseudomonas aeruginosa (PA) infections can be notoriously difficult to treat and are often accompanied by the development of antimicrobial resistance (AMR). Quorum sensing inhibitors (QSI) acting on PqsR (MvfR) – a crucial transcriptional regulator serving major functions in PA virulence – can enhance antibiotic efficacy and eventually prevent the AMR. An integrated drug discovery campaign including design, medicinal chemistry‐driven hit‐to‐lead optimization and in‐depth biological profiling of a new QSI generation is reported. The QSI possess excellent activity in inhibiting pyocyanin production and PqsR reporter‐gene with IC50 values as low as 200 and 11 × 10−9 m, respectively. Drug metabolism and pharmacokinetics (DMPK) as well as safety pharmacology studies especially highlight the promising translational properties of the lead QSI for pulmonary applications. Moreover, target engagement of the lead QSI is shown in a PA mucoid lung infection mouse model. Beyond that, a significant synergistic effect of a QSI‐tobramycin (Tob) combination against PA biofilms using a tailor‐made squalene‐derived nanoparticle (NP) formulation, which enhance the minimum biofilm eradicating concentration (MBEC) of Tob more than 32‐fold is demonstrated. The novel lead QSI and the accompanying NP formulation highlight the potential of adjunctive pathoblocker‐mediated therapy against PA infections opening up avenues for preclinical development.

Abstract Alterations of cognitive functions have been described in COPD. Our study aimed to disentangle the relationship between the degree of cognitive function and COPD characteristics including quality of life (QoL). Data from 1969 COPD patients of the COSYCONET cohort (GOLD grades 1–4; 1216 male/ 753 female; mean (SD) age 64.9 ± 8.4 years) were analysed using regression and path analysis. The DemTect screening tool was used to measure cognitive function, and the St. George‘s respiratory questionnaire (SGRQ) to assess disease-specific QoL. DemTect scores were =60 years of age. For statistical reasons, we used the average of both algorithms independent of age in all subsequent analyses. The DemTect scores were associated with oxygen content, 6-min-walking distance (6-MWD), C-reactive protein (CRP), modified Medical Research Council dyspnoea scale (mMRC) and the SGRQ impact score. Conversely, the SGRQ impact score was independently associated with 6-MWD, FVC, mMRC and DemTect. These results were combined into a path analysis model to account for direct and indirect effects. The DemTect score had a small, but independent impact on QoL, irrespective of the inclusion of COPD-specific influencing factors or a diagnosis of cognitive impairment. We conclude that in patients with stable COPD lower oxygen content of blood as a measure of peripheral oxygen supply, lower exercise capacity in terms of 6-MWD, and higher CRP levels were associated with reduced cognitive capacity. Furthermore, a reduction in cognitive capacity was associated with reduced disease-specific quality of life. As a potential clinical implication of this work, we suggest to screen especially patients with low oxygen content and low 6-MWD for cognitive impairment.

Abstract Background The combination of chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD) is associated with a higher prevalence of comorbidities and increased mortality. The impact of kidney function on patient-centered outcomes in COPD has not been evaluated. Methods Patients from the German COPD and Systemic Consequences - Comorbidities Network (COSYCONET) cohort COPD were analysed. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) measurements were

Abstract Background COPD influences cardiac function and morphology. Changes of the electrical heart axes have been largely attributed to a supposed increased right heart load in the past, whereas a potential involvement of the left heart has not been sufficiently addressed. It is not known to which extent these alterations are due to changes in lung function parameters. We therefore quantified the relationship between airway obstruction, lung hyperinflation, several echo- and electrocardiographic parameters on the orientation of the electrocardiographic (ECG) P, QRS and T wave axis in COPD. Methods Data from the COPD cohort COSYCONET were analyzed, using forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC), left ventricular (LV) mass, and ECG data. Results One thousand, one hundred and ninety-five patients fulfilled the inclusion criteria (mean ± SD age: 63.9 ± 8.4 years; GOLD 0–4: 175/107/468/363/82). Left ventricular (LV) mass decreased from GOLD grades 1–4 (p = 0.002), whereas no differences in right ventricular wall thickness were observed. All three ECG axes were significantly associated with FEV1 and FRC. The QRS axes according to GOLD grades 0–4 were (mean ± SD): 26.2° ± 37.5°, 27.0° ± 37.7°, 31.7° ± 42.5°, 46.6° ± 42.2°, 47.4° ± 49.4°. Effects of lung function resulted in a clockwise rotation of the axes by 25°-30° in COPD with severe airway disease. There were additional associations with BMI, diastolic blood pressure, RR interval, QT duration and LV mass. Conclusion Significant clockwise rotations of the electrical axes as a function of airway obstruction and lung hyperinflation were shown. The changes are likely to result from both a change of the anatomical orientation of the heart within the thoracic cavity and a reduced LV mass in COPD. The influences on the electrical axes reach an extent that could bias the ECG interpretation. The magnitude of lung function impairment should be taken into account to uncover other cardiac disease and to prevent misdiagnosis.

Abstract Background Sarcoidosis is a systemic disease of unknown etiology. The disease mechanisms are largely speculative and may include the role microbial patterns that initiate and drive an underlying immune process. The aim of this study was to characterize the microbiota of the lung of patients with sarcoidosis and compare its composition and diversity with the results from patients with other interstitial lung disease (ILD) and historic healthy controls. Methods Patients (sarcoidosis, n = 31; interstitial lung disease, n = 19) were recruited within the PULMOHOM study, a prospective cohort study to characterize inflammatory processes in pulmonary diseases. Bronchoscopy of the middle lobe or the lingula was performed and the recovered fluid was immediately sent for analysis of the pulmonary microbiota by 16sRNA gene sequencing. Subsequent bioinformatic analysis was performed to compare the groups. Results There were no significant differences between patients with sarcoidosis or other ILDs with regard to microbiome composition and diversity. In addition, the abundance of the genera Atopobium, Fusobacterium, Mycobacterium or Propionibacterium were not different between the two groups. There were no gross differences to historical healthy controls. Conclusion The analysis of the pulmonary microbiota based on 16sRNA gene sequencing did not show a significant dysbiosis in patients with sarcoidosis as compared to other ILD patients. These data do not exclude a microbiological component in the pathogenesis of sarcoidosis.

IL-17 cytokines are expressed by numerous cells (e.g., gamma delta (γδ) T, innate lymphoid (ILC), Th17, epithelial cells). They contribute to the elimination of bacteria through the induction of cytokines and chemokines which mediate the recruitment of inflammatory cells to the site of infection. However, IL-17-driven inflammation also likely promotes the progression of chronic lung diseases, such as chronic obstructive pulmonary disease (COPD), lung cancer, cystic fibrosis, and asthma. In this review, we highlight the role of IL-17 cytokines in chronic lung diseases.

Airway mucociliary regeneration and function are key players for airway defense and are impaired in chronic obstructive pulmonary disease (COPD). Using transcriptome analysis in COPD-derived bronchial biopsies, we observed a positive correlation between cilia-related genes and microRNA-449 (miR449). In vitro, miR449 was strongly increased during airway epithelial mucociliary differentiation. In vivo, miR449 was upregulated during recovery from chemical or infective insults. miR0449−/− mice (both alleles are deleted) showed impaired ciliated epithelial regeneration after naphthalene and Haemophilus influenzae exposure, accompanied by more intense inflammation and emphysematous manifestations of COPD. The latter occurred spontaneously in aged miR449−/− mice. We identified Aurora kinase A and its effector target HDAC6 as key mediators in miR449-regulated ciliary homeostasis and epithelial regeneration. Aurora kinase A is downregulated upon miR449 overexpression in vitro and upregulated in miR449−/− mouse lungs. Accordingly, imaging studies showed profoundly altered cilia length and morphology accompanied by reduced mucociliary clearance. Pharmacological inhibition of HDAC6 rescued cilia length and coverage in miR449−/− cells, consistent with its tubulin-deacetylating function. Altogether, our study establishes a link between miR449, ciliary dysfunction, and COPD pathogenesis.

Chronic obstructive pulmonary disease (COPD) is a disease with an inflammatory phenotype with increasing prevalence in the elderly. Expanded population of mutant blood cells carrying somatic mutations is termed clonal hematopoiesis of indeterminate potential (CHIP). The association between CHIP and COPD and its relevant effects on DNA methylation in aging are mainly unknown. Analyzing the deep-targeted amplicon sequencing from 125 COPD patients, we found enhanced incidence of CHIP mutations (~20%) with a predominance of DNMT3A CHIP-mediated hypomethylation of Phospholipase D Family Member 5 (PLD5), which in turn is positively correlated with increased levels of glycerol phosphocholine, pro-inflammatory cytokines, and deteriorating lung function.

Neutrophilic inflammation results in loss of lung function in chronic obstructive pulmonary disease (COPD). Gram-negative bacteria, such as nontypeable Haemophilus influenzae (NTHi), trigger acute exacerbations of COPD (AECOPD) and contribute to chronic lung inflammation. The pro-inflammatory cytokine interleukin-17C (IL-17C) is expressed by airway epithelial cells and regulates neutrophilic chemotaxis. Here, we explored the function of IL-17C in NTHi- and cigarette smoke (CS)-induced models of COPD. Neutrophilic inflammation and tissue destruction were decreased in lungs of IL-17C-deficient mice (Il-17c-/-) chronically exposed to NTHi. Numbers of pulmonary neutrophils were decreased in Il-17c-/- mice after acute exposure to the combination of NTHi and CS. However, Il-17c-/- mice were not protected from CS-induced lung inflammation. In a preliminary patient study, we show that IL-17C is present in sputum samples obtained during AECOPD and associates with disease severity. Concentrations of IL-17C were significantly increased during advanced COPD (GOLD III/IV) compared to moderate COPD (GOLD I/II). Concentrations of IL-17A and IL-17E did not associate with disease severity. Our data suggest that IL-17C promotes harmful pulmonary inflammation triggered by bacteria in COPD.

Background. In 2020, a novel coronavirus caused a global pandemic with a clinical picture termed COVID-19, accounting for numerous cases of ARDS. However, there are still other infectious causes of ARDS that should be considered, especially as the majority of these pathogens are specifically treatable. Case Presentation. We present the case of a 36-year-old gentleman who was admitted to the hospital with flu-like symptoms, after completing a half-marathon one week before admission. As infection with SARS-CoV-2 was suspected based on radiologic imaging, the hypoxemic patient was immediately transferred to the ICU, where he developed ARDS. Empiric antimicrobial chemotherapy was initiated, the patient deteriorated further, therapy was changed, and the patient was transferred to a tertiary care ARDS center. As cold agglutinins were present, the hypothesis of an infection with SARS-CoV-2 was then questioned. Bronchoscopic sampling revealed Mycoplasma (M.) pneumoniae. When antimicrobial chemotherapy was adjusted, the patient recovered quickly. Conclusion. Usually, M. pneumoniae causes mild disease. When antimicrobial chemotherapy was adjusted, the patient recovered quickly. The case underlines the importance to adhere to established treatment guidelines, scrutinize treatment modalities, and not to forget other potential causes of severe pneumonia or ARDS.

α1-antitrypsin deficiency (AATD) is a rare and under-recognised genetic condition. Owing to its low prevalence, international initiatives are key for conducting high-quality research in the field. From July 2018 to December 2019, the European Alpha-1 Research Collaboration (EARCO) developed and conducted two surveys, one for healthcare providers and one for patients and caregivers, aiming to identify research priorities and barriers in access to treatment for AATD. A survey on 164 research questions was electronically sent to 230 AATD experts in Europe, and 94 completed surveys from 24 countries were received. The top research areas identified by healthcare providers were causes of variable progression and poor outcomes, improvement in diagnosis, initiation and optimal dosing of augmentation therapy and effectiveness of self-management interventions. During the same period, 438 surveys were completed by patients and caregivers from 26 countries. The top research areas identified were improving knowledge about AATD, in particular among general practitioners, access to AATD specialised centres and access to reliable, easy to understand information about living with AATD. Regarding barriers to treatment, participants from countries where augmentation therapy was reimbursed prioritised improving knowledge in AATD, while respondents in non-reimbursed countries regarded access to AATD augmentation therapy and to specialised centres as the most relevant. The main research and management priorities identified by healthcare providers and patients included understanding the natural history of AATD, improving information to physicians, improving access to specialised reference centres, personalising treatment and having equal opportunities for access to existing therapies.

Extracorporeal membrane oxygenation (ECMO) has become an important therapeutic approach in the COVID-19 pandemic. The development and research in this field strongly relies on animal models; however, efforts are being made to find alternatives. In this work, we present a new mock circuit for ECMO that allows measurements of the oxygen transfer rate of a membrane lung at full ECMO blood flow. The mock utilizes a large reservoir of heparinized porcine blood to measure the oxygen transfer rate of the membrane lung in a single passage. The oxygen transfer rate is calculated from blood flow, hemoglobin value, venous saturation, and post-membrane arterial oxygen pressure. Before the next measuring sequence, the blood is regenerated to a venous condition with a sweep gas of nitrogen and carbon dioxide. The presented mock was applied to investigate the effect of a recirculation loop on the oxygen transfer rate of an ECMO setup. The recirculation loop caused a significant increase in post-membrane arterial oxygen pressure (paO2). The effect was strongest for the highest recirculation flow. This was attributed to a smaller boundary layer on gas fibers due to the increased blood velocity. However, the increase in paO2 did not translate to significant increases in the oxygen transfer rate because of the minor significance of physically dissolved oxygen for gas transfer. In conclusion, our results regarding a new ECMO mock setup demonstrate that recirculation loops can improve ECMO performance, but not enough to be clinically relevant.

BACKGROUND Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ in the severity of disease. We hypothesized that characteristics of SARS-CoV-2–specific immunity correlate with disease severity.METHODS In this study, SARS-CoV-2–specific T cells and antibodies were characterized in uninfected controls and patients with different coronavirus disease 2019 (COVID-19) disease severity. SARS-CoV-2–specific T cells were flow cytometrically quantified after stimulation with SARS-CoV-2 peptide pools and analyzed for expression of cytokines (IFN-γ, IL-2, and TNF-α) and markers for activation, proliferation, and functional anergy. SARS-CoV-2–specific IgG and IgA antibodies were quantified using ELISA. Moreover, global characteristics of lymphocyte subpopulations were compared between patient groups and uninfected controls.RESULTS Despite severe lymphopenia affecting all major lymphocyte subpopulations, patients with severe disease mounted significantly higher levels of SARS-CoV-2–specific T cells as compared with convalescent individuals. SARS-CoV-2–specific CD4+ T cells dominated over CD8+ T cells and closely correlated with the number of plasmablasts and SARS-CoV-2–specific IgA and IgG levels. Unlike in convalescent patients, SARS-CoV-2–specific T cells in patients with severe disease showed marked alterations in phenotypical and functional properties, which also extended to CD4+ and CD8+ T cells in general.CONCLUSION Given the strong induction of specific immunity to control viral replication in patients with severe disease, the functionally altered characteristics may result from the need for contraction of specific and general immunity to counteract excessive immunopathology in the lung.FUNDING The study was supported by institutional funds to MS and in part by grants of Saarland University, the State of Saarland, and the Rolf M. Schwiete Stiftung.

Patients with pre-existing comorbidities and immunosuppression are at greater risk for SARS-CoV-2 infection and severe manifestations of COVID-19. This also includes cancer patients, who are shown to have a poor prognosis after infection. Here, we describe the case of a 72-year old male patient with B-cell depletion after maintenance treatment with rituximab for non-Hodgkin-lymphoma who had a prolonged COVID-19 course and initial false negative test results. Our case highlights the diagnostic pitfalls in diagnosing COVID-19 in B-cell depleted patients and discuss the role of B-cell depletion in the course and treatment of COVID-19. Furthermore, we investigated peripheral blood monocytes and SARS-CoV-2 specific T cells in our patient. In conclusion, our case report can help physicians to avoid diagnostic pitfalls for COVID-19 in hemato-oncological patients under chemoimmunotherapy and tries to explain the role of B-cell depletion and SARS-CoV-2 specific T cells in this context.

Background Air trapping and lung hyperinflation are major determinants of prognosis and response to therapy in chronic obstructive pulmonary disease (COPD). They are often determined by body plethysmography, which has limited availability, and so the question arises as to what extent they can be estimated via spirometry. Methods We used data from visits 1–5 of the COPD cohort COSYCONET. Predictive parameters were derived from visit 1 data, while visit 2–5 data was used to assess reproducibility. Pooled data then yielded prediction models including sex, age, height, and body mass index as covariates. Hyperinflation was defined as ratio of residual volume (RV) to total lung capacity (TLC) above the upper limit of normal. (ClinicalTrials.gov identifier: NCT01245933). Results Visit 1 data from 1988 patients (Global Initiative for Chronic Obstructive Lung Disease grades 1–4, n=187, 847, 766, 188, respectively) were available for analysis (n=1231 males, 757 females; mean±sd age 65.1±8.4 years; forced expiratory volume in 1 s (FEV1) 53.1±18.4 % predicted (% pred); forced vital capacity (FVC) 78.8±18.8 % pred; RV/TLC 0.547±0.107). In total, 7157 datasets were analysed. Among measures of hyperinflation, RV/TLC showed the closest relationship to FEV1 % pred and FVC % pred, which were sufficient for prediction. Their relationship to RV/TLC could be depicted in nomograms. Even when neglecting covariates, hyperinflation was predicted by FEV1 % pred, FVC % pred or their combination with an area under the curve of 0.870, 0.864 and 0.889, respectively. Conclusions The degree of air trapping/hyperinflation in terms of RV/TLC can be estimated in a simple manner from forced spirometry, with an accuracy sufficient for inferring the presence of hyperinflation. This may be useful for clinical settings, where body plethysmography is not available.

Rationale and objectives Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that leads to an increased risk of emphysema and liver disease. Despite extensive investigation, there remain unanswered questions concerning the natural history, pathophysiology, genetics and the prognosis of the lung disease in association with AATD. The European Alpha-1 Clinical Research Collaboration (EARCO) is designed to bring together researchers from European countries and to create a standardised database for the follow-up of patients with AATD. Study design and population The EARCO Registry is a non-interventional, multicentre, pan-European, longitudinal observational cohort study enrolling patients with AATD. Data will be collected prospectively without interference/modification of patient's management by the study team. The major inclusion criterion is diagnosed severe AATD, defined by an AAT serum level