EBioMedicine (Sep 2022)

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

  • Susanne Krasemann,
  • Carsten Dittmayer,
  • Saskia von Stillfried,
  • Jenny Meinhardt,
  • Fabian Heinrich,
  • Kristin Hartmann,
  • Susanne Pfefferle,
  • Edda Thies,
  • Regina von Manitius,
  • Tom Alex David Aschman,
  • Josefine Radke,
  • Anja Osterloh,
  • Simone Schmid,
  • Eva Miriam Buhl,
  • Jana Ihlow,
  • Frank Dubois,
  • Viktor Arnhold,
  • Sefer Elezkurtaj,
  • David Horst,
  • Andreas Hocke,
  • Sara Timm,
  • Sebastian Bachmann,
  • Victor Corman,
  • Hans-Hilmar Goebel,
  • Jakob Matschke,
  • Stephanie Stanelle-Bertram,
  • Gülsah Gabriel,
  • Danielle Seilhean,
  • Homa Adle-Biassette,
  • Benjamin Ondruschka,
  • Matthias Ochs,
  • Werner Stenzel,
  • Frank L. Heppner,
  • Peter Boor,
  • Helena Radbruch,
  • Michael Laue,
  • Markus Glatzel

Journal volume & issue
Vol. 83
p. 104193

Abstract

Read online

Summary: 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.

Keywords