Abstract
Introduction: The pandemic of a novel coronavirus disease 2019 (COVID-19) caused by a severe acute respiratory coronavirus 2 (SARS-CoV-2) infection has been problematic worldwide. A new SARS-CoV-2 antigen test (LUMIPULSE Ⓡ ) was licensed and widely used in Japan since May 2020. We conducted this study intending to whether the automated quantitative CLEIA antigen test using a saliva sample is effective and valid for the diagnosis of COVID-19.
Patients and methods: We analyzed and compared the diagnostic accuracy of both the automated quantitative CLEIA antigen test and real-time RT-PCR (rRT-PCR) using a saliva sample from individuals suspected as having COVID-19.
Results: A total of 305 samples were collected and tested in Aichi Medical University Hospital and affiliated facilities from December 2020 until January 2021 at our institute. Using reverse-transcription PCR as a reference, the AUROC of the automated quantitative CLEIA antigen test was 0.903 (95% confidential interval 0.845-0.962, p < 0.001). The appropriate cut-off antigen level was 4.0 pg/mL and had a sensitivity of 77.8%, a specificity of 99.6%, a positive predictive value of 98%, and a negative predictive value of 94.5%. On the other hand, the diagnostic accuracy of the antigen test decreased among patients among patients with COVID-19 with threshold cycle (Ct-value)≥27, which shows the AUROC was 0.795 (95%CI 0.687-0.907, p < 0.001).
Conclusion: While the automated quantitative CLEIA antigen test from saliva specimen could be one of the most useful diagnostic tests for the diagnosis of COVID-19 in general practice, clinicians should know the limitations of the antigen test.
Keywords: COVID-19; Quantitative chemiluminescent enzyme immunoassay; RT-PCR; SARS-CoV-2; Saliva.
【저자키워드】 COVID-19, SARS-CoV-2, Saliva, RT-PCR, Quantitative chemiluminescent enzyme immunoassay, 【초록키워드】 Saliva, pandemic, diagnostic test, Infection, diagnostic, novel coronavirus disease, Antigen, sensitivity, specificity, rRT-PCR, PCR, Positive predictive value, Accuracy, Patient, Japan, automated, real-time RT-PCR, threshold, university, Quantitative, Negative predictive value, 95%CI, clinician, enzyme, individual, specimen, limitation, AUROC, cut-off, while, effective, Respiratory Coronavirus, new SARS-CoV-2, tested, analyzed, collected, caused, conducted, confidential interval, diagnosis of COVID-19, patients with COVID-19, 【제목키워드】 Saliva, immunoassay, Validity, automated, SARS-CoV-2 antigen, Quantitative, enzyme, specimen, diagnosis of COVID-19,