Post-mortem examination plays a pivotal role in understanding the pathobiology of the SARS-CoV-2; thus, the optimization of virus detection on the post-mortem formalin-fixed paraffin-embedded (FFPE) tissue is needed. Different techniques are available for the identification of the SARS-CoV-2, including reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), in situ hybridization (ISH), and electron microscopy. The main goal of this study is to compare ISH versus RT-PCR to detect SARS-CoV-2 on post-mortem lung samples of positive deceased subjects. A total of 27 samples were analyzed by RT-PCR targeting different viral RNA sequences of SARS-CoV-2, including envelope (E), nucleocapsid (N), spike (S), and open reading frame (ORF1ab) genes and ISH targeting S and Orf1ab. All 27 cases showed the N gene amplification, 22 out of 27 the E gene amplification, 26 out of 27 the S gene amplification, and only 6 the ORF1ab gene amplification. The S ISH was positive only in 12 out of 26 cases positive by RT-PCR. The S ISH positive cases with strong and diffuse staining showed a correlation with low values of the number of the amplification cycles by S RT-PCR suggesting that ISH is a sensitive assay mainly in cases carrying high levels of S RNA. In conclusion, our findings demonstrated that ISH assay has lower sensitivity to detect SARS-CoV-2 in FFPE compared to RT-PCR; however, it is able to localize the virus in the cellular context since it preserves the morphology. Supplementary Information The online version contains supplementary material available at 10.1007/s00428-021-03262-8.
【저자키워드】 SARS-CoV-2, Reverse transcription polymerase chain reaction (RT-PCR), In situ hybridization (ISH), Post-mortem lung samples, Spike(S), Open reading frame (ORF1ab), 【초록키워드】 immunohistochemistry, RT-PCR, virus, RNA, reverse transcription polymerase chain reaction, polymerase chain reaction, amplification, sensitivity, electron microscopy, Viral, FFPE, nucleocapsid, Microscopy, virus detection, envelope, Post-mortem, morphology, reverse transcription, Viral RNA, N gene, correlation, optimization, In situ hybridization, ORF1ab gene, cellular, S gene, Open reading frame, Deceased, ORF1ab, gene amplification, Chain Reaction, formalin, Frame, supplementary material, tissue, E gene, sequence, staining, positive, ORF1, formalin-fixed paraffin-embedded, paraffin, amplification cycles, IHC, polymerase chain, analyzed, detect, subjects, demonstrated, amplification cycle, post-mortem lung, the SARS-CoV-2, 【제목키워드】 RNA, variable, post-mortem lung,