tetano
Editor, Senior Moderator
J Infect Chemother
. 2020 Dec 3;S1341-321X(20)30428-1.
doi: 10.1016/j.jiac.2020.11.021. Online ahead of print.
Clinical validation of quantitative SARS-CoV-2 antigen assays to estimate SARS-CoV-2 viral loads in nasopharyngeal swabs
Kotaro Aoki[SUP] 1 [/SUP], Tatsuya Nagasawa[SUP] 1 [/SUP], Yoshikazu Ishii[SUP] 2 [/SUP], Shintaro Yagi[SUP] 3 [/SUP], Sadatsugu Okuma[SUP] 3 [/SUP], Katsuhito Kashiwagi[SUP] 4 [/SUP], Tadashi Maeda[SUP] 4 [/SUP], Taito Miyazaki[SUP] 4 [/SUP], Sadako Yoshizawa[SUP] 1 [/SUP], Kazuhiro Tateda[SUP] 1 [/SUP]
Affiliations
Abstract
Background: Expansion of the testing capacity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important issue to mitigate the pandemic of coronavirus disease-2019 (COVID-19) caused by this virus. Recently, a sensitive quantitative antigen test (SQT), Lumipulse? SARS-CoV-2 Ag, was developed. It is a fully automated chemiluminescent enzyme immunoassay system for SARS-CoV-2.
Methods: In this study, the analytical performance of SQT was examined using clinical specimens from nasopharyngeal swabs using reverse transcription polymerase chain reaction (RT-PCR) as a control.
Results: Receiver operating characteristic analysis of 24 SARS-CoV-2-positive and 524 -negative patients showed an area under the curve of 0.957 ? 0.063. Using a cut-off value of 1.34 pg/ml, the sensitivity was 91.7%, the specificity was 98.5%, and the overall rate of agreement was 98.2%. In the distribution of negative cases, the 99.5 percentile value was 1.03 pg/ml. There was a high correlation between the viral load calculated using the cycle threshold value of RT-PCR and the concentration of antigen. The tendency for the antigen concentration to decrease with time after disease onset correlated with that of the viral load.
Conclusions: Presented results indicate that SQT is highly concordant with RT-PCR and should be useful for the diagnosis of COVID-19 in any clinical setting. Therefore, this fully automated kit will contribute to the expansion of the testing capability for SARS-CoV-2.
Keywords: Chemiluminescent enzyme immunoassay; Covid-19; Nasopharyngeal swab; Nasopharynx; SARS-CoV-2; Saliva; Sensitive quantitative antigen test.
. 2020 Dec 3;S1341-321X(20)30428-1.
doi: 10.1016/j.jiac.2020.11.021. Online ahead of print.
Clinical validation of quantitative SARS-CoV-2 antigen assays to estimate SARS-CoV-2 viral loads in nasopharyngeal swabs
Kotaro Aoki[SUP] 1 [/SUP], Tatsuya Nagasawa[SUP] 1 [/SUP], Yoshikazu Ishii[SUP] 2 [/SUP], Shintaro Yagi[SUP] 3 [/SUP], Sadatsugu Okuma[SUP] 3 [/SUP], Katsuhito Kashiwagi[SUP] 4 [/SUP], Tadashi Maeda[SUP] 4 [/SUP], Taito Miyazaki[SUP] 4 [/SUP], Sadako Yoshizawa[SUP] 1 [/SUP], Kazuhiro Tateda[SUP] 1 [/SUP]
Affiliations
- PMID: 33423918
- DOI: 10.1016/j.jiac.2020.11.021
Abstract
Background: Expansion of the testing capacity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an important issue to mitigate the pandemic of coronavirus disease-2019 (COVID-19) caused by this virus. Recently, a sensitive quantitative antigen test (SQT), Lumipulse? SARS-CoV-2 Ag, was developed. It is a fully automated chemiluminescent enzyme immunoassay system for SARS-CoV-2.
Methods: In this study, the analytical performance of SQT was examined using clinical specimens from nasopharyngeal swabs using reverse transcription polymerase chain reaction (RT-PCR) as a control.
Results: Receiver operating characteristic analysis of 24 SARS-CoV-2-positive and 524 -negative patients showed an area under the curve of 0.957 ? 0.063. Using a cut-off value of 1.34 pg/ml, the sensitivity was 91.7%, the specificity was 98.5%, and the overall rate of agreement was 98.2%. In the distribution of negative cases, the 99.5 percentile value was 1.03 pg/ml. There was a high correlation between the viral load calculated using the cycle threshold value of RT-PCR and the concentration of antigen. The tendency for the antigen concentration to decrease with time after disease onset correlated with that of the viral load.
Conclusions: Presented results indicate that SQT is highly concordant with RT-PCR and should be useful for the diagnosis of COVID-19 in any clinical setting. Therefore, this fully automated kit will contribute to the expansion of the testing capability for SARS-CoV-2.
Keywords: Chemiluminescent enzyme immunoassay; Covid-19; Nasopharyngeal swab; Nasopharynx; SARS-CoV-2; Saliva; Sensitive quantitative antigen test.