Diagnostic Accuracy of SARS-CoV-2 Nucleocapsid Antigen Self-Test in Comparison to Reverse Transcriptase–Polymerase Chain Reaction.

Autor: Sukumaran, Ajaikumar, Suvekbala, Vemparthan, R, Arun Krishnan, Thomas, Rhema Elizabeth, Raj, Aneesh, Thomas, Thushara, Abhijith, B L, Jose, Jisha, Paul, Jofy K, Vasudevan, D M
Předmět:
Zdroj: Journal of Applied Laboratory Medicine; Jul2022, Vol. 7 Issue 4, p871-880, 10p
Abstrakt: Background: Currently, the rapid antigen test (RAT) and reverse transcriptase–polymerase chain reaction (RT–PCR) are considered the main stakeholders in COVID-19 diagnosis. In RT–PCR, any of at least 2 evolutionary conserved genes (RdRP, E-, N-, ORF1ab gene) and S-gene of SARS-CoV-2 are endorsed, and in RAT, the nucleocapsid antigen (N-Ag) of SARS-CoV-2 is considered due to its stability and fewer chances of mutation effects. In the present work, we evaluated the performance of the AG-Q COVID-19 N-Ag self-test kit and conducted a validation study in comparison with the RT–PCR. Methods: AG-Q COVID-19 N-Ag rapid test kit is an Indian Council of Medical Research (ICMR) approved product developed and marketed by Agappe Diagnostics Limited. The RT–PCR assay was performed with a COVIPATH COVID-19 RT–PCR kit from Thermo Fisher Scientific. Results: We observed 19 false-negative results in antigen self-tests, including samples of threshold cycle (Ct) values 22/22 (N-gene/ORF1ab-gene) in RT–PCR, indicating inadequate sampling by the patients in self-tests, leading to false-negative results and increased chances of the disease spreading. Based on the RT–PCR Ct value vs antigen self-test comparison, it is evident that proper sampling is crucial in performing antigen self-tests. Also, there were weak positive results in antigen self-tests with a Ct value of 18/19 in RT–PCR. Conclusions: Although the sensitivity and diagnostic accuracy offered by the AG-Q COVID-19 N-Antigen self-test in comparison with RT–PCR fulfills the ICMR tenets for RAT, this study recommends the laboratory/hospital-based RAT execution would be appropriate, rather than the self-test. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index