Cardiac SARS-CoV-2 infection is associated with pro-inflammatory transcriptomic alterations within the heart.

AIMS: Cardiac involvement in COVID-19 is associated with adverse outcome. However, it is unclear whether cell-specific consequences are associated with cardiac SARS-CoV-2 infection. Therefore, we investigated heart tissue utilizing in situ hybridization, immunohistochemistry, and RNA-sequencing in consecutive autopsy cases to quantify virus load and characterize cardiac involvement in COVID-19. METHODS AND RESULTS: In this study, 95 SARS-CoV-2-positive autopsy cases were included. A relevant SARS-CoV-2 virus load in the cardiac tissue was detected in 41/95 deceased (43%). Massive analysis of cDNA ends (MACE)-RNA-sequencing was performed to identify molecular pathomechanisms caused by the infection of the heart. A signature matrix was generated based on the single-cell dataset 'Heart Cell Atlas' and used for digital cytometry on the MACE-RNA-sequencing data. Thus, immune cell fractions were estimated and revealed no difference in immune cell numbers in cases with and without cardiac infection. This result was confirmed by quantitative immunohistological diagnosis. MACE-RNA-sequencing revealed 19 differentially expressed genes (DEGs) with a q-value <0.05 (e.g. up: IFI44L, IFT3, TRIM25; down: NPPB, MB, MYPN). The upregulated DEGs were linked to interferon pathways and originate predominantly from endothelial cells. In contrast, the downregulated DEGs originate predominately from cardiomyocytes. Immunofluorescent staining showed viral protein in cells positive for the endothelial marker ICAM1 but rarely in cardiomyocytes. The Gene Ontology (GO) term analysis revealed that downregulated GO terms were linked to cardiomyocyte structure, whereas upregulated GO terms were linked to anti-virus immune response. CONCLUSION: This study reveals that cardiac infection induced transcriptomic alterations mainly linked to immune response and destruction of cardiomyocytes. While endothelial cells are primarily targeted by the virus, we suggest cardiomyocyte destruction by paracrine effects. Increased pro-inflammatory gene expression was detected in SARS-CoV-2-infected cardiac tissue but no increased SARS-CoV-2 associated immune cell infiltration was observed.

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.

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.

[SARS-CoV­2 incidental findings among Hamburg deaths: an epidemiological monitoring during the dynamic infection event in spring 2020]. / SARS-CoV­2-Zufallsentdeckungen bei Hamburger Todesfällen: ein epidemiologisches Monitoring während des dynamischen Infektionsgeschehens im Frühjahr 2020.

Background: In the context of the COVID-19-pandemic, mortality and incidence are key determinants to assess the transmission dynamics and the resulting potential threat. Systematic microbiological monitoring of deaths provides a fundamental basis to particularly assess underrecording of community-acquired mortality. It should be further elucidated whether a death cohort of previously unreported cases may be structurally different from the cohort of officially registered cases. Methods: A systematic reverse transcription (RT) qPCR testing for SARS-CoV­2 infections from nasopharyngeal swab samples was carried out. A representative sample of corpses from crematoria and the Institute of Legal Medicine of the Federal State of Hamburg were included. A comparative analysis of primarily reported and unreported fatalities in an 8­week period after occurrence of the first pandemic-related deaths in Hamburg was performed. Results: A total of 1231 deaths were included, all of which were previously unsuspicious for SARS-CoV­2 infection. Thereof 29 cases of previously unknown infections were recorded. In the first phase of the pandemic, incidental findings predominantly occurred among younger people from domestic environments with unclear or unnatural manner of death at the Institute of Legal Medicine. Over time, incidental findings investigated at the crematoria increased, mostly related to nursing home residents. The overall cohort showed no significant sociodemographic differences to a comparative collective of known SARS-CoV­2-associated deaths. Primarily unreported cases showed a significantly lower proportion of COVID-19 as the underlying cause of death. Conclusion: A systematic PCR-based monitoring of deaths allows a more targeted detection and classification of SARS-CoV­2 positive cases. A preventive contribution can be made by disclosing unreported pandemic-related cases of death.

Postmortem Stability of SARS-CoV-2 in Nasopharyngeal Mucosa.

Analyses of infection chains have demonstrated that severe acute respiratory syndrome coronavirus 2 is highly transmissive. However, data on postmortem stability and infectivity are lacking. Our finding of nasopharyngeal viral RNA stability in 79 corpses showed no time-dependent decrease. Maintained infectivity is supported by virus isolation up to 35 hours postmortem.

Association of Cardiac Infection With SARS-CoV-2 in Confirmed COVID-19 Autopsy Cases.

Importance: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be documented in various tissues, but the frequency of cardiac involvement as well as possible consequences are unknown. Objective: To evaluate the presence of SARS-CoV-2 in the myocardial tissue from autopsy cases and to document a possible cardiac response to that infection. Design, Setting, and Participants: This cohort study used data from consecutive autopsy cases from Germany between April 8 and April 18, 2020. All patients had tested positive for SARS-CoV-2 in pharyngeal swab tests. Exposures: Patients who died of coronavirus disease 2019. Main Outcomes and Measures: Incidence of SARS-CoV-2 positivity in cardiac tissue as well as CD3+, CD45+, and CD68+ cells in the myocardium and gene expression of tumor necrosis growth factor α, interferon γ, chemokine ligand 5, as well as interleukin-6, -8, and -18. Results: Cardiac tissue from 39 consecutive autopsy cases were included. The median (interquartile range) age of patients was 85 (78-89) years, and 23 (59.0%) were women. SARS-CoV-2 could be documented in 24 of 39 patients (61.5%). Viral load above 1000 copies per µg RNA could be documented in 16 of 39 patients (41.0%). A cytokine response panel consisting of 6 proinflammatory genes was increased in those 16 patients compared with 15 patients without any SARS-CoV-2 in the heart. Comparison of 15 patients without cardiac infection with 16 patients with more than 1000 copies revealed no inflammatory cell infiltrates or differences in leukocyte numbers per high power field. Conclusions and Relevance: In this analysis of autopsy cases, viral presence within the myocardium could be documented. While a response to this infection could be reported in cases with higher virus load vs no virus infection, this was not associated with an influx of inflammatory cells. Future investigations should focus on evaluating the long-term consequences of this cardiac involvement.

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

Autopsies of deceased with a confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can provide important insights into the novel disease and its course. Furthermore, autopsies are essential for the correct statistical recording of the coronavirus disease 2019 (COVID-19) deaths. In the northern German Federal State of Hamburg, all deaths of Hamburg citizens with ante- or postmortem PCR-confirmed SARS-CoV-2 infection have been autopsied since the outbreak of the pandemic in Germany. Our evaluation provides a systematic overview of the first 80 consecutive full autopsies. A proposal for the categorisation of deaths with SARS-CoV-2 infection is presented (category 1: definite COVID-19 death; category 2: probable COVID-19 death; category 3: possible COVID-19 death with an equal alternative cause of death; category 4: SARS-CoV-2 detection with cause of death not associated to COVID-19). In six cases, SARS-CoV-2 infection was diagnosed postmortem by a positive PCR test in a nasopharyngeal or lung tissue swab. In the other 74 cases, SARS-CoV-2 infection had already been known antemortem. The deceased were aged between 52 and 96 years (average 79.2 years, median 82.4 years). In the study cohort, 34 deceased were female (38%) and 46 male (62%). Overall, 38% of the deceased were overweight or obese. All deceased, except for two women, in whom no significant pre-existing conditions were found autoptically, had relevant comorbidities (in descending order of frequency): (1) diseases of the cardiovascular system, (2) lung diseases, (3) central nervous system diseases, (4) kidney diseases, and (5) diabetes mellitus. A total of 76 cases (95%) were classified as COVID-19 deaths, corresponding to categories 1-3. Four deaths (5%) were defined as non-COVID-19 deaths with virus-independent causes of death. In eight cases, pneumonia was combined with a fulminant pulmonary artery embolism. Peripheral pulmonary artery embolisms were found in nine other cases. Overall, deep vein thrombosis has been found in 40% of the cases. This study provides the largest overview of autopsies of SARS-CoV-2-infected patients presented so far.