TNFα aggravates detrimental effects of SARS-CoV-2 infection in the liver.

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus does not only lead to pulmonary infection but can also infect other organs such as the gut, the kidney, or the liver. Recent studies confirmed that severe cases of COVID-19 are often associated with liver damage and liver failure, as well as the systemic upregulation of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFα). However, the impact these immune mediators in the liver have on patient survival during SARS-CoV-2 infection is currently unknown. Here, by performing a post-mortem analysis of 45 patients that died from a SARS-CoV-2 infection, we find that an increased expression of TNFA in the liver is associated with elevated mortality. Using publicly available single-cell sequencing datasets, we determined that Kupffer cells and monocytes are the main sources of this TNFα production. Further analysis revealed that TNFα signaling led to the upregulation of pro-inflammatory genes that are associated with an unfavorable outcome. Moreover, high levels of TNFA in the liver were associated with lower levels of interferon alpha and interferon beta. Thus, TNFα signaling in the infected SARS-CoV-2 liver correlates with reduced interferon levels and overall survival time.

Predictors of Loneliness among Homeless Individuals in Germany during the COVID-19 Pandemic.

PURPOSE: The aim of the study was to identify the frequency of loneliness and to examine the factors associated with loneliness among homeless individuals in Germany during the COVID-19 pandemic. METHODS: Data were taken from the 'national survey on the psychiatric and somatic health of homeless individuals during the COVID-19 pandemic'. The data collection took place from 26th July to 17th September 2021 (the analytical sample included n = 491 observations). The well-established UCLA-3 tool was used to quantify loneliness. Independent variables included sex, age, marital status, the existence of children and pets, level of education, country of origin, duration of homelessness, alcohol and drug consumption, mental health concerns and concerns regarding COVID-19 illness. Multiple logistic regressions were used to examine the predictors of loneliness. RESULTS: The frequency of loneliness was 41.7% for the total sample. Multiple logistic regression analysis stratified by gender showed that a higher likelihood of loneliness was associated with being born in Germany, being middle aged (40 to 49 years compared to 18 to 29 years), having mental health problems and a short period of homelessness (1 month compared to longer periods) among women. In men, a higher likelihood of loneliness was associated with a higher fear of COVID-19 and a short period of homelessness. CONCLUSIONS: Our study revealed a high frequency rate of loneliness among homeless individuals. The study results highlight the associations between some explanatory variables (i.e., the duration of homelessness and mental health problems). Identifying the factors associated with loneliness may help to adequately address the problems of homeless individuals at risk of loneliness. Longitudinal studies are required to confirm our findings.

New Postmortem Perspective on Emerging SARS-CoV-2 Variants of Concern, Germany.

We performed autopsies on persons in Germany who died from COVID-19 and observed higher nasopharyngeal SARS-CoV-2 viral loads for variants of concern (VOC) compared with non-VOC lineages. Pulmonary inflammation and damage appeared higher in non-VOC than VOC lineages until adjusted for vaccination status, suggesting COVID-19 vaccination may mitigate pulmonary damage.

Autopsy Findings and Venous Thromboembolism in Patients With COVID-19: A Prospective Cohort Study.

BACKGROUND: The new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused more than 210 000 deaths worldwide. However, little is known about the causes of death and the virus's pathologic features. OBJECTIVE: To validate and compare clinical findings with data from medical autopsy, virtual autopsy, and virologic tests. DESIGN: Prospective cohort study. SETTING: Autopsies performed at a single academic medical center, as mandated by the German federal state of Hamburg for patients dying with a polymerase chain reaction-confirmed diagnosis of COVID-19. PATIENTS: The first 12 consecutive COVID-19-positive deaths. MEASUREMENTS: Complete autopsy, including postmortem computed tomography and histopathologic and virologic analysis, was performed. Clinical data and medical course were evaluated. RESULTS: Median patient age was 73 years (range, 52 to 87 years), 75% of patients were male, and death occurred in the hospital (n = 10) or outpatient sector (n = 2). Coronary heart disease and asthma or chronic obstructive pulmonary disease were the most common comorbid conditions (50% and 25%, respectively). Autopsy revealed deep venous thrombosis in 7 of 12 patients (58%) in whom venous thromboembolism was not suspected before death; pulmonary embolism was the direct cause of death in 4 patients. Postmortem computed tomography revealed reticular infiltration of the lungs with severe bilateral, dense consolidation, whereas histomorphologically diffuse alveolar damage was seen in 8 patients. In all patients, SARS-CoV-2 RNA was detected in the lung at high concentrations; viremia in 6 of 10 and 5 of 12 patients demonstrated high viral RNA titers in the liver, kidney, or heart. LIMITATION: Limited sample size. CONCLUSION: The high incidence of thromboembolic events suggests an important role of COVID-19-induced coagulopathy. Further studies are needed to investigate the molecular mechanism and overall clinical incidence of COVID-19-related death, as well as possible therapeutic interventions to reduce it. PRIMARY FUNDING SOURCE: University Medical Center Hamburg-Eppendorf.

Fear of COVID-19 among homeless individuals in Germany in mid-2021.

Aims: To investigate the prevalence and the correlates of fear of COVID-19 among homeless individuals. Methods: We used data from the "national survey on psychiatric and somatic health of homeless individuals during the COVID-19 pandemic" (NAPSHI-study) which took place in several large cities in Germany in Mid-2021 (n = 666 in the analytical sample). Mean age equaled 43.3 years (SD: 12.1 years), ranging from 18 to 80 years. Multiple linear regressions were performed. Results: In our study, 70.9% of the homeless individuals reported no fear of COVID-19. Furthermore, 14.0% reported a little fear of COVID-19, 8.4% reported some fear of COVID-19 and 6.7% reported severe fear of COVID-19. Multiple linear regressions revealed that fear of COVID-19 was higher among individuals aged 50-64 years (compared to individuals aged 18-29 years: ß = 0.28, p < 0.05), among individuals with a higher perceived own risk of contracting the coronavirus 1 day (ß = 0.28, p < 0.001) as well as among individuals with a higher agreement that a diagnosis of the coronavirus would ruin his/her life (ß = 0.15, p < 0.001). Conclusions: Only a small proportion of homeless individuals reported fear of COVID-19 in mid-2021 in Germany. Such knowledge about the correlates of higher levels of fear of COVID-19 may be helpful for addressing certain risk groups (e.g., homeless individuals aged 50-64 years). In a further step, avoiding extraordinarily high levels of fear of COVID-19 may be beneficial to avoid irrational thinking and acting regarding COVID-19 in this group.

Assessing and improving the validity of COVID-19 autopsy studies - A multicentre approach to establish essential standards for immunohistochemical and ultrastructural analyses.

BACKGROUND: Autopsy studies have provided valuable insights into the pathophysiology of COVID-19. Controversies remain about whether the clinical presentation is due to direct organ damage by SARS-CoV-2 or secondary effects, such as overshooting immune response. SARS-CoV-2 detection in tissues by RT-qPCR and immunohistochemistry (IHC) or electron microscopy (EM) can help answer these questions, but a comprehensive evaluation of these applications is missing. METHODS: We assessed publications using IHC and EM for SARS-CoV-2 detection in autopsy tissues. We systematically evaluated commercially available antibodies against the SARS-CoV-2 proteins in cultured cell lines and COVID-19 autopsy tissues. In a multicentre study, we evaluated specificity, reproducibility, and inter-observer variability of SARS-CoV-2 IHC. We correlated RT-qPCR viral tissue loads with semiquantitative IHC scoring. We used qualitative and quantitative EM analyses to refine criteria for ultrastructural identification of SARS-CoV-2. FINDINGS: Publications show high variability in detection and interpretation of SARS-CoV-2 abundance in autopsy tissues by IHC or EM. We show that IHC using antibodies against SARS-CoV-2 nucleocapsid yields the highest sensitivity and specificity. We found a positive correlation between presence of viral proteins by IHC and RT-qPCR-determined SARS-CoV-2 viral RNA load (N= 35; r=-0.83, p-value <0.0001). For EM, we refined criteria for virus identification and provide recommendations for optimized sampling and analysis. 135 of 144 publications misinterpret cellular structures as virus using EM or show only insufficient data. We provide publicly accessible digitized EM sections as a reference and for training purposes. INTERPRETATION: Since detection of SARS-CoV-2 in human autopsy tissues by IHC and EM is difficult and frequently incorrect, we propose criteria for a re-evaluation of available data and guidance for further investigations of direct organ effects by SARS-CoV-2. FUNDING: German Federal Ministry of Health, German Federal Ministry of Education and Research, Berlin University Alliance, German Research Foundation, German Center for Infectious Research.

New Insights in the Occurrence of Venous Thromboembolism in Critically Ill Patients with COVID-19-A Large Postmortem and Clinical Analysis.

Critically ill COVID-19 patients are at high risk for venous thromboembolism (VTE), namely deep vein thrombosis (DVT) and/or pulmonary embolism (PE), and death. The optimal anticoagulation strategy in critically ill patients with COVID-19 remains unknown. This study investigated the ante mortem incidence as well as postmortem prevalence of VTE, the factors predictive of VTE, and the impact of changed anticoagulation practice on patient survival. We conducted a consecutive retrospective analysis of postmortem COVID-19 (n = 64) and non-COVID-19 (n = 67) patients, as well as ante mortem COVID-19 (n = 170) patients admitted to the University Medical Center Hamburg-Eppendorf (Hamburg, Germany). Baseline patient characteristics, parameters related to the intensive care unit (ICU) stay, and the clinical and autoptic presence of VTE were evaluated and statistically compared between groups. The occurrence of VTE in critically ill COVID-19 patients is confirmed in both ante mortem (17%) and postmortem (38%) cohorts. Accordingly, comparing the postmortem prevalence of VTE between age- and sex-matched COVID-19 (43%) and non-COVID-19 (0%) cohorts, we found the statistically significant increased prevalence of VTE in critically ill COVID-19 cohorts (p = 0.001). A change in anticoagulation practice was associated with the statistically significant prolongation of survival time (HR: 2.55, [95% CI 1.41-4.61], p = 0.01) and a reduction in VTE occurrence (54% vs. 25%; p = 0.02). In summary, in the autopsy as well as clinical cohort of critically ill patients with COVID-19, we found that VTE was a frequent finding. A change in anticoagulation practice was associated with a statistically significantly prolonged survival time.

Natural killer cell-mediated ADCC in SARS-CoV-2-infected individuals and vaccine recipients.

COVID-19, caused by SARS-CoV-2, has emerged as a global pandemic. While immune responses of the adaptive immune system have been in the focus of research, the role of NK cells in COVID-19 remains less well understood. Here, we characterized NK cell-mediated SARS-CoV-2 antibody-dependent cellular cytotoxicity (ADCC) against SARS-CoV-2 spike-1 (S1) and nucleocapsid (NC) protein. Serum samples from SARS-CoV-2 resolvers induced significant CD107a-expression by NK cells in response to S1 and NC, while serum samples from SARS-CoV-2-negative individuals did not. Furthermore, serum samples from individuals that received the BNT162b2 vaccine induced strong CD107a expression by NK cells that increased with the second vaccination and was significantly higher than observed in infected individuals. As expected, vaccine-induced responses were only directed against S1 and not against NC protein. S1-specific CD107a responses by NK cells were significantly correlated to NK cell-mediated killing of S1-expressing cells. Interestingly, screening of serum samples collected prior to the COVID-19 pandemic identified two individuals with cross-reactive antibodies against SARS-CoV-2 S1, which also induced degranulation of NK cells. Taken together, these data demonstrate that antibodies induced by SARS-CoV-2 infection and anti-SARS-CoV-2 vaccines can trigger significant NK cell-mediated ADCC activity, and identify some cross-reactive ADCC-activity against SARS-CoV-2 by endemic coronavirus-specific antibodies.

The blood-brain barrier is dysregulated in COVID-19 and serves as a CNS entry route for SARS-CoV-2.

Neurological complications are common in COVID-19. Although SARS-CoV-2 has been detected in patients' brain tissues, its entry routes and resulting consequences are not well understood. Here, we show a pronounced upregulation of interferon signaling pathways of the neurovascular unit in fatal COVID-19. By investigating the susceptibility of human induced pluripotent stem cell (hiPSC)-derived brain capillary endothelial-like cells (BCECs) to SARS-CoV-2 infection, we found that BCECs were infected and recapitulated transcriptional changes detected in vivo. While BCECs were not compromised in their paracellular tightness, we found SARS-CoV-2 in the basolateral compartment in transwell assays after apical infection, suggesting active replication and transcellular transport of virus across the blood-brain barrier (BBB) in vitro. Moreover, entry of SARS-CoV-2 into BCECs could be reduced by anti-spike-, anti-angiotensin-converting enzyme 2 (ACE2)-, and anti-neuropilin-1 (NRP1)-specific antibodies or the transmembrane protease serine subtype 2 (TMPRSS2) inhibitor nafamostat. Together, our data provide strong support for SARS-CoV-2 brain entry across the BBB resulting in increased interferon signaling.

Replication of SARS-CoV-2 in adipose tissue determines organ and systemic lipid metabolism in hamsters and humans.

Zickler et al. describe SARS-CoV-2 RNA in post-mortem samples of human adipose tissue. In the hamster model, SARS-CoV-2 propagation in adipose tissue leads to specific changes in lipid metabolism, which are reflected in lipidome patterns of hamster and human plasma.

SARS-CoV-2 Blood RNA Load Predicts Outcome in Critically Ill COVID-19 Patients.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA loads in patient specimens may act as a clinical outcome predictor in critically ill patients with coronavirus disease 2019 (COVID-19). METHODS: We evaluated the predictive value of viral RNA loads and courses in the blood compared with the upper and lower respiratory tract loads of critically ill COVID-19 patients. Daily specimen collection and viral RNA quantification by reverse transcription quantitative polymerase chain reaction were performed in all consecutive 170 COVID-19 patients between March 2020 and February 2021 during the entire intensive care unit (ICU) stay (4145 samples analyzed). Patients were grouped according to their 90-day outcome as survivors (n=100) or nonsurvivors (n=70). RESULTS: In nonsurvivors, blood SARS-CoV-2 RNA loads were significantly higher at the time of admission to the ICU (P=.0009). Failure of blood RNA clearance was observed in 33/50 (66%) of the nonsurvivors compared with 12/64 (19%) survivors (P<.0001). As determined by multivariate analysis, taking sociodemographic and clinical parameters into account, blood SARS-CoV-2 RNA load represents a valid and independent predictor of outcome in critically ill COVID-19 patients (odds ratio [OR; log10], 0.23; 95% CI, 0.12-0.42; P<.0001), with a significantly higher effect for survival compared with respiratory tract SARS-CoV-2 RNA loads (OR [log10], 0.75; 95% CI, 0.66-0.85; P<.0001). Blood RNA loads exceeding 2.51×103 SARS-CoV-2 RNA copies/mL were found to indicate a 50% probability of death. Consistently, 29/33 (88%) nonsurvivors with failure of virus clearance exceeded this cutoff value constantly. CONCLUSIONS: Blood SARS-CoV-2 load is an important independent outcome predictor and should be further evaluated for treatment allocation and patient monitoring.

Postmortem Antigen-Detecting Rapid Diagnostic Tests to Predict Infectivity of SARS-CoV-2-Associated Deaths.

We investigated the infectivity of 128 severe acute respiratory disease coronavirus 2-associated deaths and evaluated predictive values of standard diagnostic procedures. Maintained infectivity (20%) did not correlate with viral RNA loads but correlated well with anti-S antibody levels. Sensitivity >90% for antigen-detecting rapid diagnostic tests supports their usefulness for assessment.

Prospective postmortem evaluation of 735 consecutive SARS-CoV-2-associated death cases.

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic with significant mortality. Accurate information on the specific circumstances of death and whether patients died from or with SARS-CoV-2 is scarce. To distinguish COVID-19 from non-COVID-19 deaths, we performed a systematic review of 735 SARS-CoV-2-associated deaths in Hamburg, Germany, from March to December 2020, using conventional autopsy, ultrasound-guided minimally invasive autopsy, postmortem computed tomography and medical records. Statistical analyses including multiple logistic regression were used to compare both cohorts. 84.1% (n = 618) were classified as COVID-19 deaths, 6.4% (n = 47) as non-COVID-19 deaths, 9.5% (n = 70) remained unclear. Median age of COVID-19 deaths was 83.0 years, 54.4% were male. In the autopsy group (n = 283), the majority died of pneumonia and/or diffuse alveolar damage (73.6%; n = 187). Thromboses were found in 39.2% (n = 62/158 cases), pulmonary embolism in 22.1% (n = 56/253 cases). In 2020, annual mortality in Hamburg was about 5.5% higher than in the previous 20 years, of which 3.4% (n = 618) represented COVID-19 deaths. Our study highlights the need for mortality surveillance and postmortem examinations. The vast majority of individuals who died directly from SARS-CoV-2 infection were of advanced age and had multiple comorbidities.

Multiorgan tropism of SARS-CoV-2 lineage B.1.1.7.

Due to the development of novel functionalities, distinct SARS-CoV-2 variants such as B.1.1.7 fuel the current pandemic. B.1.1.7 is not only more transmissible, but may also cause an increased mortality compared to previous SARS-CoV-2 variants. Human tissue analysis of the SARS-CoV-2 lineage B.1.1.7 is urgently needed, and we here present autopsy data from 7 consecutive SARS-CoV-2 B.1.1.7 cases. The initial RT-qPCR analyses from nasopharyngeal swabs taken post mortem included typing assays for B.1.1.7. We quantitated SARS-CoV-2 B.1.1.7 viral load in autopsy tissue of multiple organs. Highest levels of SARS-CoV-2 B.1.1.7 copies normalized to ß-globin were detected in the respiratory system (lung and pharynx), followed by the liver and heart. Importantly, SARS-CoV-2 lineage B.1.1.7 was found in 100% of cases in the lungs and in 85.7% in pharynx tissue. Detection also in the kidney and brain highlighting a pronounced organ tropism. Comparison of the given results to a former cohort of SARS-CoV-2 deaths during the first wave in spring 2020 showed resembling organ tropism. Our results indicate that also SARS-CoV-2 B.1.1.7 has a relevant organ tropism beyond the respiratory tract. We speculate that B.1.1.7 spike protein's affinity to human ACE2 facilitates transmission, organ tropism, and ultimately morbidity and mortality. Further studies and larger cohorts are obligatory to proof this link.

Determinants of health care use among homeless individuals: evidence from the Hamburg survey of homeless individuals.

BACKGROUND: To identify the determinants of health care use among homeless individuals. METHODS: Data were taken from the Hamburg survey of homeless individuals (n = 100 individuals in the here used model, mean age 44.8 years, SD 12.5) focusing on homeless individuals in Hamburg, Germany. The number of physician visits in the past 3 months and hospitalization in the preceding 12 months were used as outcome measures. Drawing on the Andersen model of health care use as a conceptual framework, predisposing characteristics, enabling resources and need factors as well as psychosocial variables were included as correlates. RESULTS: Negative binomial regressions showed that increased physician visits were associated with being female (IRR: 4.02 [95% CI: 1.60-10.11]), absence of chronic alcohol consume (IRR: 0.26 [95% CI: 0.12-0.57]) and lower health-related quality of life (IRR: 0.97 [95% CI: 0.96-0.98]). Furthermore, logistic regressions showed that the likelihood of hospitalization was positively associated with lower age (OR: 0.93 [95% CI: 0.89-0.98]), having health insurance (OR: 8.11 [2.11-30.80]) and lower health-related quality of life (OR: 0.97 [95% CI: 0.94-0.99]). CONCLUSIONS: Our study showed that predisposing characteristics (both age and sex), enabling resources (i.e., health insurance) and need factors in terms of health-related quality of life are main drivers of health care use among homeless individuals. This knowledge may assist in managing health care use.

Correction to: Dying with SARS-CoV-2 infection-an autopsy study of the first consecutive 80 cases in Hamburg, Germany.

The affiliation of the author Martin Aepfelbacher was incorrectly assigned in the manuscript. Martin Aepfelbacher is affiliated to the Institute of Microbiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, instead.

Prevalence and Factors Associated with Fear of COVID-19 Among Homeless Individuals During the COVID-19 Pandemic: Evidence from the Hamburg Survey of Homeless Individuals.

PURPOSE: To clarify the prevalence and determinants of fear of COVID-19 among homeless individuals during the COVID-19 pandemic. PATIENTS AND METHODS: Data were taken from the Hamburg survey of homeless individuals (n=150) covering homeless adults in Hamburg, Germany. Multiple linear regressions were used. Beyond sociodemographic and lifestyle-related independent variables, COVID-19-related factors were also used as independent variables. RESULTS: In sum, 56.2% of homeless individuals reported no fear of COVID-19, 23.8% reported a little fear of COVID-19, 9.2% reported some fear of COVID-19 and 10.8% reported severe fear of COVID-19. Regressions showed that an increased fear of COVID-19 was significantly associated with younger age (ß=-.01, p<0.05), absence of chronic alcohol consume (ß=-.55, p<0.01), an increased perceived own risk of getting infected with the coronavirus one day (ß=0.42, p<0.001) and a higher agreement that a diagnosis of the coronavirus would ruin his/her life (ß=0.13, p<0.01). CONCLUSION: Given the poor hygienic conditions and their increased vulnerability, data surprisingly suggest a quite low fear of COVID-19 among homeless individuals. Efforts may be beneficial which contribute to thinking rationally about COVID-19 among homeless people, since low levels of fear of COVID-19 may contribute to careless behavior and can lead to super-spreading events.

Targeting Runt-Related Transcription Factor 1 Prevents Pulmonary Fibrosis and Reduces Expression of Severe Acute Respiratory Syndrome Coronavirus 2 Host Mediators.

Pulmonary fibrosis (PF) can arise from unknown causes, as in idiopathic PF, or as a consequence of infections, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current treatments for PF slow, but do not stop, disease progression. We report that treatment with a runt-related transcription factor 1 (RUNX1) inhibitor (Ro24-7429), previously found to be safe, although ineffective, as a Tat inhibitor in patients with HIV, robustly ameliorates lung fibrosis and inflammation in the bleomycin-induced PF mouse model. RUNX1 inhibition blunted fundamental mechanisms downstream pathologic mediators of fibrosis and inflammation, including transforming growth factor-ß1 and tumor necrosis factor-α, in cultured lung epithelial cells, fibroblasts, and vascular endothelial cells, indicating pleiotropic effects. RUNX1 inhibition also reduced the expression of angiotensin-converting enzyme 2 and FES Upstream Region (FURIN), host proteins critical for SARS-CoV-2 infection, in mice and in vitro. A subset of human lungs with SARS-CoV-2 infection overexpress RUNX1. These data suggest that RUNX1 inhibition via repurposing of Ro24-7429 may be beneficial for PF and to battle SARS-CoV-2, by reducing expression of viral mediators and by preventing respiratory complications.