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Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience

The objective of the present study was to evaluate the true positivity among people, whose results of initial testing of nasopharyngeal swabs (NPS) showed a very low viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Seventy-seven people detected with low viral loads of SARs...

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Autores principales: Florou, Zoe, Zigra, Meropi, Kartalidis, Philippos, Tsilipounidaki, Katerina, Papadamou, Georgia, Belia, Aikaterini, Fthenakis, George C., Petinaki, Efthymia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8230444/
https://www.ncbi.nlm.nih.gov/pubmed/34200837
http://dx.doi.org/10.3390/microorganisms9061263
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author Florou, Zoe
Zigra, Meropi
Kartalidis, Philippos
Tsilipounidaki, Katerina
Papadamou, Georgia
Belia, Aikaterini
Fthenakis, George C.
Petinaki, Efthymia
author_facet Florou, Zoe
Zigra, Meropi
Kartalidis, Philippos
Tsilipounidaki, Katerina
Papadamou, Georgia
Belia, Aikaterini
Fthenakis, George C.
Petinaki, Efthymia
author_sort Florou, Zoe
collection PubMed
description The objective of the present study was to evaluate the true positivity among people, whose results of initial testing of nasopharyngeal swabs (NPS) showed a very low viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Seventy-seven people detected with low viral loads of SARs-CoV-2 in nasopharyngeal samples (Ct ≥ 35) were enrolled in the study. For this purpose, a second NPS was collected for rRT-PCR (real-time reverse transcription polymerase chain reaction) combined with a pair of serum samples for detection of anti-nucleocapsid (anti-N) and anti-spike (anti-S) antibodies. In 8 people, subsequent examinations indicated an increase in viral loads, thereafter, followed by an increase of anti-N and anti-S antibodies, findings compatible with an early stage of COVID-19 infection. In 9 people, who already had increased anti-N antibodies, subsequent examination showed a decrease or absence of viral load and an increase in antibodies, indicative of a late stage of COVID-19 infection. In 60 people, subsequent examination showed absence of infection (as indicated by absence of viral load and antibodies). We propose that the combination of a second NPS and one serum-specimen, both taken three days after the first NPS, helps significantly to avoid false-positive results.
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spelling pubmed-82304442021-06-26 Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience Florou, Zoe Zigra, Meropi Kartalidis, Philippos Tsilipounidaki, Katerina Papadamou, Georgia Belia, Aikaterini Fthenakis, George C. Petinaki, Efthymia Microorganisms Communication The objective of the present study was to evaluate the true positivity among people, whose results of initial testing of nasopharyngeal swabs (NPS) showed a very low viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Seventy-seven people detected with low viral loads of SARs-CoV-2 in nasopharyngeal samples (Ct ≥ 35) were enrolled in the study. For this purpose, a second NPS was collected for rRT-PCR (real-time reverse transcription polymerase chain reaction) combined with a pair of serum samples for detection of anti-nucleocapsid (anti-N) and anti-spike (anti-S) antibodies. In 8 people, subsequent examinations indicated an increase in viral loads, thereafter, followed by an increase of anti-N and anti-S antibodies, findings compatible with an early stage of COVID-19 infection. In 9 people, who already had increased anti-N antibodies, subsequent examination showed a decrease or absence of viral load and an increase in antibodies, indicative of a late stage of COVID-19 infection. In 60 people, subsequent examination showed absence of infection (as indicated by absence of viral load and antibodies). We propose that the combination of a second NPS and one serum-specimen, both taken three days after the first NPS, helps significantly to avoid false-positive results. MDPI 2021-06-10 /pmc/articles/PMC8230444/ /pubmed/34200837 http://dx.doi.org/10.3390/microorganisms9061263 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Communication
Florou, Zoe
Zigra, Meropi
Kartalidis, Philippos
Tsilipounidaki, Katerina
Papadamou, Georgia
Belia, Aikaterini
Fthenakis, George C.
Petinaki, Efthymia
Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience
title Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience
title_full Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience
title_fullStr Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience
title_full_unstemmed Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience
title_short Combination of rRT-PCR and Anti-Nucleocapsid/Anti-Spike Antibodies to Characterize Specimens with Very Low Viral SARs-CoV-2 Load: A Real-Life Experience
title_sort combination of rrt-pcr and anti-nucleocapsid/anti-spike antibodies to characterize specimens with very low viral sars-cov-2 load: a real-life experience
topic Communication
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8230444/
https://www.ncbi.nlm.nih.gov/pubmed/34200837
http://dx.doi.org/10.3390/microorganisms9061263
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