Abstract
Background: SARS-CoV-2 is an RNA virus that primarily causes respiratory disease; however, infection of other tissue has been reported. Evaluation of SARS-CoV-2 in tissue specimens may increase understanding of SARS-CoV-2 pathobiology. Materials and Methods: A qualitative test for detection of SARS-CoV-2 in formalin-fixed paraffin-embedded (FFPE) tissues was developed and validated using droplet digital PCR (ddPCR), which has a lower limit of detection than reverse transcription (RT)-qPCR. After extraction of total RNA from unstained FFPE tissue, SARS-CoV-2 nucleocapsid (N1, N2) target sequences were amplified and quantified, along with human RPP30 as a control using the Bio-Rad SARS-CoV-2 ddPCR kit. Results: SARS-CoV-2 was detected in all 21 known positive samples and none of the 16 negative samples. As few as approximately 5 viral copies were reliably detected. Since January 2021, many tissue types have been clinically tested. Of the 195 clinical specimens, the positivity rate was 35% with placenta and fetal tissue showing the highest percentage of positive cases. Conclusion: This sensitive FFPE-based assay has broad clinical utility with applications as diverse as pregnancy loss and evaluation of liver transplant rejection. This assay will aid in understanding atypical presentations of COVID-19 as well as long-term sequelae.
Original language | English (US) |
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Pages (from-to) | 181-187 |
Number of pages | 7 |
Journal | Clinica Chimica Acta |
Volume | 532 |
DOIs | |
State | Published - Jul 1 2022 |
Keywords
- COVID-19
- Droplet digital PCR
- Placental viral infection
- SARS-CoV-2
- Tissue-based viral detection
- Viral detection in FFPE
ASJC Scopus subject areas
- Biochemistry
- Clinical Biochemistry
- Biochemistry, medical