Abstract
Background: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is generally diagnosed by reverse transcription (RT)-PCR or serological assays. The SARS-CoV-2 viral load decreases a few days after symptom onset. Thus, the RT-PCR sensitivity peaks at three days after symptom onset (approximately 80%). We evaluated the performance of the ARCHITECT ® SARS-CoV-2 IgG assay (henceforth termed IgG assay; Abbott Laboratories, Lake County, IL, USA), and the combination of RT-PCR and the IgG assay for COVID-19 diagnosis.
Methods: In this retrospective study, 206 samples from 70 COVID-19 cases at two hospitals in Tokyo that were positive using RT-PCR were used to analyze the diagnostic sensitivity. RT-PCR-negative (N=166), COVID-19-unrelated (N=418), and Japanese Red Cross Society (N=100) samples were used to evaluate specificity.
Results: Sensitivity increased daily after symptom onset and exceeded 84.4% after 10 days. Specificity ranged from 98.2% to 100% for samples from the three case groups. Seroconversion was confirmed from 9 to 20 days after symptom onset in 18 out of 32 COVID-19 cases with multiple samples and from another case with a positive result in the IgG assay for the first available sample.
Conclusions: The combination of RT-PCR and IgG assay improves the robustness of laboratory diagnostics by compensating for the limitations of each method.
Keywords: ARCHITECT®; COVID-19; Immunoassay; Reverse transcription (RT)-PCR; SARS-CoV-2 IgG; Sensitivity; Specificity.
【저자키워드】 COVID-19, immunoassay, sensitivity, specificity, SARS-CoV-2 IgG, ARCHITECT®, Reverse transcription (RT)-PCR, 【초록키워드】 SARS-CoV-2, IgG, Coronavirus disease 2019, coronavirus, hospital, Transcription, diagnostic, RT-PCR, diagnostics, Laboratory, Retrospective study, specificity, serological assays, COVID-19 diagnosis, reverse transcription, Japanese, USA, Combination, Tokyo, symptom onset, Society, acute respiratory syndrome, COVID-19 case, positive result, SARS-CoV-2 viral load, limitation, Abbott Laboratories, positive, decrease, IMPROVE, evaluate, caused, diagnosed, evaluated, were used, groups, exceeded, ranged, compensating, Lake, Red, 【제목키워드】 RT-PCR, Improved,