Interspecies analysis to dissect cellular transcriptomic signatures of humans and hamsters in COVID-19

The ongoing corona virus disease 2019 (COVID-19) pandemic has led to an urgent demand for appropriate models depicting host-pathogen interactions and disease severity-dependent immune responses. Amongst various animal models, hamster species are particularly valuable as they are permissive to develop a moderate (Mesocricetus auratus) or severe (Phodopus roborovskii) disease course following infection. Here, we use single-cell ribonucleic acid sequencing of white blood cells to dissect cell-specific changes in moderate and severe disease courses of hamsters infected with severe acute respiratory syndrome coronavirus 2. To determine universal and species-specific transcriptional responses, the generated datasets were integrated with two publicly available datasets of human COVID-19 patients (Schulte-Schrepping et al. 2020 and Su et al. 2020) featuring all disease severities. Datasets were integrated using the R package Harmony and the Python package scGen enabling the prediction of disease states through different species using an autoencoder neural network architecture. Specifically, application of a low dimensional latent space embedding allows capturing most relevant transcriptome data structures, identifying shift vectors from healthy to diseased cells as well as interspecies differences. Preliminary results show that interspecies integration of hamster and human data is achievable, and major cell types were identified throughout the datasets. Training of a neuronal network on human blood monocytes enables the prediction of transcriptomic disease severity specific patterns, paving the way for extended analyses involving several cell types and species. In addition to in-depth analysis of COVID-19 signatures in blood of hamsters and humans, successfully established workflows could subsequently be used to study the pathology of extensive lung diseases, shedding light on cellular mechanisms in the transition from healthy to diseased cellular states.

Impact of COVID-19 on hospital admissions, health status and behavioral changes of patients with severe COPD

Introduction: COPD patients have an increased risk of severe Covid-19, which is why self-isolation was recommended. However, over the long period of lockdown social isolation accompanied with limit access to health care systems might negatively influence outcome of patients with severe COPD. Aims and objectives: Our aim was to investigate the impact of COVID-19 lockdown on hospital admissions, health status and behavioral changes in patients with severe COPD. Method(s): We compared the admissions of all patients at Charite-Universitatsmedizin with COPD or pneumonia between 2020 and 2021 to pre-lockdown between 2012 and 2019. In addition, 52 patients with severe COPD received questionnaires regarding health status and behavioral changes from June 2020 to April 2021. Result(s): During the COVID-19 pandemic, there was a significant decrease of 29.3 % in COPD admissions in 2020 and 2021 in coincidence with lockdown measures in Germany, which was not associated with an increasing number of ventilated cases and mortality in patients with COPD. Over 50% of patients with severe COPD reported social distancing and behavioral changes over the lockdown periods, which was associated by subjective feelings of increasing COPD symptoms and overall deterioration of general health the longer the lockdown last. Conclusion(s): In summary, this study showed reduced COPD admission during COVID-19 pandemic lockdowns, which was not associated with an increased mortality or morbidity - even if patients with severe COPD reported deteriorations of their health as a result of strict compliance to lockdown measures.

Severity score-based study of predictors and clinical correlates of Post-COVID Syndrome (PCS)in Germany

Background: Post-COVID Syndrome (PCS) is an important sequela of COVID-19, characterised by symptom persistence >3 months, subacute symptom onset, and worsening of pre-existing comorbidities. The causes and public health impact of PCS are still unclear, not least for the lack of efficient means to assess the presence and severity of PCS. Method(s): COVIDOM is a population-based cohort study of PCR-confirmed cases of SARS-CoV-2 infection, recruited through local public health authorities in three German regions. Standardised interviews and in-depth onsite examinations were scheduled 6-12 months post infection. Based upon 12 long-term symptom complexes, we developed a comprehensive PCS severity score in a training cohort and validated the score in two independent subcohorts. Result(s): In the training sub-cohort (n=667, 56% female), 90% of participants were treated as outpatients for acute COVID-19. Neurological ailments (61.5%) and fatigue (57.1%) persisted most frequently. Across all sub-cohorts, higher PCS scores were associated with lower health-related quality of life (EQ-5D-5L-VAS/-index, all p<0.001). Similarly, participants with a higher PCS score consistently showed increased blood inflammatory markers and Ddimer as well as lower diffusing capacity in lung function (all p<0.01). Significant early predictors of the PCS score included the number and intensity of acute symptoms, resilience, and general anxiousness. Conclusion(s): PCS severity can be quantified by an easy-to-use score summarising individual disease burden and reflecting pathological processes. The PCS score promises to facilitate diagnosis of PCS, studies of its natural course, and of therapeutic interventions.

Phase 3 RCT of C5a-Specific Vilobelimab in Severe COVID-19 Pneumonia

Background: Blocking the C5a-C5aR axis in COVID-19 patients could improve outcomes by limiting myeloid cell infiltration in damaged organs and preventing excessive lung inflammation and endothelialitis. Aims and Objectives: Vilobelimab (VILO), an anti-C5a mAb that preserves the membrane attack complex (MAC), was tested in a Phase III adaptively designed multicenter, double-blind placebo (P)-controlled study for survival in critically ill COVID-19 patients. Method(s): COVID-19 pneumonia patients (N=369;VILO n=178, P n=191) within 48 hrs of intubation were randomly assigned to receive 6, 800 mg infusions of VILO or P on top of standard of care. Primary outcome was 28-day allcause mortality. Result(s): 28-day all-cause mortality was 31.7% VILO vs 41.6% P (Kaplan-Meier estimates;Cox regression site stratified, HR 0.73;95%CI:0.50-1.06;P=0.094) with a 22.7% relative mortality reduction to Day 60. In predefined primary outcome analysis without site stratification, VILO significantly reduced 28-day mortality (HR 0.67;95%CI:0.48-0.96;P=0.027);needed to treat number, 10 to save 1. VILO significantly reduced 28-day mortality in severe patients with baseline WHO ordinal scale score of 7 (n=237, HR 0.62;95%CI:0.40-0.95;P=0.028) or severe ARDS/PaO2/FiO2<=100 mmHg (n=98, HR 0.55;95%CI:0.30-0.98;P=0.044) or eGFR<60 mL/min/1.73m2 (n=108, HR 0.55;95%CI:0.31-0.96;P=0.036). Treatment emergent AEs were 90.9% VILO vs 91.0% P. Infections were comparable;VILO (62.9%), P (59.3%). Serious AEs were 58.9% VILO, 63.5% P. Conclusion(s): VILO reduced mortality at 28 to 60 days in severe COVID-19 pneumonia patients with no increase in infections suggesting the importance of targeting C5a while preserving MAC.

Single cell mRNA sequencing of nasal swabs indicate an impaired ciliated cell function in COVID-19 convalescents with persisting dyspnea

COVID-19 convalescents often experience persistent symptoms such as fatigue, neurologic complications or dyspnea, often referred to as "long COVID". To elucidate molecular mechanisms underlying ongoing dyspnea in COVID-19 convalescents, we analyzed single-cell RNA sequencing data from nasal swabs collected during acute infection, and three, six and twelve months post infection together with matching healthy controls. Patients with and without persisting symptoms and with varying severity during the acute phase were included. Post infection, we observed a time-dependent decrease in immune cells. Transcriptional analysis of nasal epithelial cells provided evidence of an impaired cilia assembly, organization and function in COVID-19 convalescents with dyspnea compared to healthy controls and convalescents without ongoing respiratory symptoms. Moreover, differences in the differentiation trajectories of ciliated cells were evident between patients with and without dyspnea, with less diverse differentiation endpoints in the dyspnea patients than in healthy controls or convalescents without respiratory impairment. Overall, our analyses revealed a potential deficiency of ciliated cells in COVID-19 convalescents with dyspnea compared to convalescents without ongoing respiratory symptoms or compared with healthy controls. Ciliated cells clear the lung from particles and mucus. If these cells are functionally impaired, pathogens remain in the airways, causing respiratory problems and infections. Thus, it is reasonable to assume, that impaired ciliated cell function contributes to the persistent respiratory symptoms seen in COVID-19 convalescents.

Persisting chemosensory dysfunction in COVID-19 - a cross-sectional population-based survey.

BACKGROUND: Chemosensory dysfunction (CD) has been reported as a common symptom of SARS-CoV-2 infection, but it is not well understood whether and for how long changes of smell, taste and chemesthesis persist in infected individuals. METHODOLOGY: Unselected adult residents of the German federal state of Schleswig-Holstein with Polymerase Chain Reaction (PCR)-test-confirmed SARS-CoV-2 infection were invited to participate in this large cross-sectional study. Data on the medical history and subjective chemosensory function of participants were obtained through questionnaires and visual analogue scales (VAS). Olfactory function (OF) was objectified with the Sniffin' Sticks test (SST), including threshold (T), discrimination (D) and identification (I) test as well as summarized TDI score, and compared to that in healthy controls. Gustatory function (GF) was evaluated with the suprathreshold taste strips (TS) test, and trigeminal function was tested with an ampoule containing ammonia. RESULTS: Between November 2020 and June 2021, 667 infected individuals (mean age: 48.2 years) were examined 9.1 months, on average, after positive PCR testing. Of these, 45.6% had persisting subjective olfactory dysfunction (OD), 36.2% had subjective gustatory dysfunction (GD). Tested OD, tested GD and impaired trigeminal function were observed in 34.6%, 7.3% and 1.8% of participants, respectively. The mean TDI score of participants was significantly lower compared to healthy subjects. Significant associations were observed between subjective OD and GD, and between tested OD and GD. CONCLUSION: Nine months after SARS-CoV-2 infection, OD prevalence is significantly increased among infected members of the general population. Therefore, OD should be included in the list of symptoms collectively defining Long-COVID.

Randomized, Controlled Phase 3 Study of anti-C5a Vilobelimab's Effect on Mortality in Critically Ill COVID-19 Patients: A Therapy for Viral Pneumonia

Background. SARS-CoV-2 induces endothelial damage and activates the complement system. In severe COVID-19 patients, complement split factor C5a is highly elevated leading to inflammation that contributes to multiorgan failure. The anti-C5a monoclonal antibody, Vilobelimab (Vilo), which preserves the membrane attack complex (MAC), was investigated in an adaptively designed, randomized doubleblind, placebo (P)-controlled Phase 3 international multicenter study for survival in critically ill COVID-19 patients (pts). Methods. COVID-19 pneumonia pts (N=368;Vilo n=177, P n=191), mechanically ventilated within 48 hrs before treatment, received up to 6, 800 mg infusions of Vilo or P on top of standard of care. The primary and main secondary endpoints were 28-day (d) and 60-d all-cause mortality. Results. Pts enrolled in the study were on corticosteroids (97%) and anticoagulants (98%) as standard of care. A smaller proportion (20%) were either continuing or had taken immunomodulators such as tocilizumab and baricitinib prior to receiving Vilo. The 28-d all-cause mortality was 31.7% with Vilo vs 41.6% with P (Kaplan-Meier estimates;Cox regression site-stratified, HR 0.73;95% CI:0.50-1.06;P=0.094), representing a 23.8% relative mortality reduction. In predefined primary outcome analysis without site stratification, however, Vilo significantly reduced mortality at 28 (HR 0.67;95% CI:0.48-0.96;P=0.027) and 60 days (HR 0.67;95% CI:0.48-0.92;P=0.016). Vilo also significantly reduced 28-d mortality in more severe pts with baseline WHO ordinal scale score of 7 (n=237, HR 0.62;95% CI:0.40-0.95;P=0.028), severe ARDS/PaO2/FiO2 <= 100 mmHg (n=98, HR 0.55;95% CI:0.30-0.98;P=0.044) and eGFR < 60 mL/min/1.73m2 (n=108, HR 0.55;95% CI:0.31-0.96;P=0.036). Treatment-emergent AEs were 90.9% Vilo vs 91.0% P. Infections were comparable: Vilo 62.9%, P 59.3%. Infection incidence per 100 Pt days were equal. No meningococcal infections were reported. Serious AEs were 58.9% Vilo, 63.5% P. Conclusion. Vilo significantly reduced mortality at 28 and 60 days in critically ill COVID-19 pts with no increase in infections suggesting the importance of targeting C5a while preserving MAC. Vilo targets inflammation which may represent an approach to treat sepsis and ARDS caused by other respiratory viruses. (Figure Presented).

Stress myocardial blood flow reduced after severe COVID-19, not related to symptoms

Introduction: Persistent cardiopulmonary symptoms after COVID-19 are reported in a large number of patients and the underlying pathology is still poorly understood. (1) Histopathologic studies revealed myocardial macrophage infiltrates in deceased patients, likely an unspecific finding of severe illness, and increased prevalence of micro- and macrovascular thrombi. (2) We examined whether microvascular perfusion, measured by quantitative cardiac magnetic resonance under vasodilator stress, was altered post COVID-19. Methods: Our population consisted of 12 patients from the Pa-COVID- 19-Study of the Charité Berlin, which received a cardiac MRI as part of a systematic follow up post discharge, 10 patients that presented at the German Heart Center Berlin with persistent cardiac symptoms post COVID-19 and 12 patients from the Kings College London referred for stress MRI and previous COVID-19. The scan protocol included standard functional, edema and scar imaging and quantitative stress and rest perfusion to assess both macro- and microvascular coronary artery disease. The pharmacological stress agent was regadenosone in 20 and adenosine in 13 of the patients. To control for the higher heart rate increase under regadenosone compared to adenosine, we calculated the myocardial blood flow per heartbeat (MBFΔHRi) under stress. Results: The median time between first positive PCR for COVID-19 and the CMR exam was 2 months (Range 0 to 12). None of the 33 patients exhibited signs of myocardial edema. One patient with a previous history of myocarditis had focal fibrosis. Three patients with known coronary artery disease showed ischemic Late Enhancement. Five patients had a small pericardial effusion;one of these four patients showed slight focal pericardial edema and LGE, consistent with mild focal pericarditis. Five Patients had a stress-induced focal perfusion deficit. Mean Stress MBFΔHRi was 32.5±6.5 μl/beat/g. Stress MBFΔHRi was negatively correlated with COVID-19 severity (rho=-0.361, P=0.039) and age (r=-0.452, P=0.009). The correlation with COVID-19 severity remained significant after controlling for age (rho=-0.390, P=0.027). There was no apparent difference in stress MBFΔHRi between patients with and without persistent chest pain (34.5 vs. 31.5 μl/beat/g, P=0.229) Conclusion: While vasodilator-stress myocardial blood flow after COVID- 19 was negatively correlated to COVID-19 severity, it was not correlated to the presence of chest pain. The etiology of persistent cardiac symptoms after COVID-19 remains unclear. (Figure Presented).

Long-term health sequelae and quality of life at least 6 months after infection with SARS-CoV-2: design and rationale of the COVIDOM-study as part of the NAPKON population-based cohort platform (POP).

PURPOSE: Over the course of COVID-19 pandemic, evidence has accumulated that SARS-CoV-2 infections may affect multiple organs and have serious clinical sequelae, but on-site clinical examinations with non-hospitalized samples are rare. We, therefore, aimed to systematically assess the long-term health status of samples of hospitalized and non-hospitalized SARS-CoV-2 infected individuals from three regions in Germany. METHODS: The present paper describes the COVIDOM-study within the population-based cohort platform (POP) which has been established under the auspices of the NAPKON infrastructure (German National Pandemic Cohort Network) of the national Network University Medicine (NUM). Comprehensive health assessments among SARS-CoV-2 infected individuals are conducted at least 6 months after the acute infection at the study sites Kiel, Würzburg and Berlin. Potential participants were identified and contacted via the local public health authorities, irrespective of the severity of the initial infection. A harmonized examination protocol has been implemented, consisting of detailed assessments of medical history, physical examinations, and the collection of multiple biosamples (e.g., serum, plasma, saliva, urine) for future analyses. In addition, patient-reported perception of the impact of local pandemic-related measures and infection on quality-of-life are obtained. RESULTS: As of July 2021, in total 6813 individuals infected in 2020 have been invited into the COVIDOM-study. Of these, about 36% wished to participate and 1295 have already been examined at least once. CONCLUSION: NAPKON-POP COVIDOM-study complements other Long COVID studies assessing the long-term consequences of an infection with SARS-CoV-2 by providing detailed health data of population-based samples, including individuals with various degrees of disease severity. TRIAL REGISTRATION: Registered at the German registry for clinical studies (DRKS00023742).

[Responsibilities of Weaning Centers during the COVID-19 Pandemic Outbreak - Recommendations for the Assignment of ICU Capacities in COVID-19 Patients as shown by the Berlin-Brandenburg POST-SAVE-Model]. / Aufgaben der Weaning-Zentren im Pandemiefall COVID-19.

The enormous increase in patients with severe respiratory distress due to the COVID-19 pandemic outbreak requires a systematic approach to optimize ventilated patient at risk flow. A standardised algorithm called "SAVE" was developed to distribute patients with COVID-19 respiratory distress syndrome requiring invasive ventilation. This program is established by now in Berlin. An instrumental bottleneck of this approach is the vacant slot assignment in the intensive care unit to guarantee constant patient flow. The transfer of the patients after acute care treatment is needed urgently to facilitate the weaning process. In a next step we developed a triage algorithm to identify patients at SAVE intensive care units with potential to wean and transfer to weaning institutions - we called POST SAVE. This manuscript highlights the algorithms including the use of a standardised digital evaluation tool, the use of trained navigators to facilitate the communication between SAVE intensive care units and weaning institutions and the establishment of a prospective data registry for patient assignment and reevaluation of the weaning potential in the future.