Quantification of SARS-CoV-2 antigen levels in the blood of patients with COVID-19
SCIENCE CHINA LIFE SCIENCES | NOVEMBER 26, 2020
Su B, Yin J, Lin X, Zhang T, Yao X, Xu Y, Lu Y, Wang W, Liu K, Zhang J, Xie L, Jin R and Feng Y.
Sci. China Life Sci. (2020)
This study was peformed using a Simoa® Homebrew assay.
Severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) has caused the global outbreak of coronavirus disease 2019 (COVID-19). By far, more than 35 million people had been infected by SARS-CoV-2, resulting in more than 1 million deaths globally. It is well recognized that SARSCoV-2 preferentially attacks pulmonary epithelial cells,leading to acute respiratory distress syndrome (ARDS). Remarkably, infected patients experience liver (Phipps et al.,2020), kidney (Gabarre et al., 2020) or heart injury (Bavishi et al., 2020), indicating the presence of multiple-organ dysfunction via viremia.By far, viral detection in RNA extracted from nasopharyngeal swabs, saliva, sputum, and bronchoalveolar lavage fluid has remained the standard etiological diagnostic procedure for COVID-19, with the detection rate ranging from 70% to more than 90% (Lippi et al., 2020). Paradoxically, the viral RNA detection rate is only 15%–30% in blood samples
(Scohy et al., 2020; Mak et al., 2020). Moreover, hampered by the low performance of the current technology, few studies have evaluated SARS-CoV-2 antigen levels in the blood. The single molecular array (SIMOA™) ultrasensitive platform employs enzyme-conjugated microscopic beads for protein capture and enables antigen quantification at femtomolar concentrations (Rissin et al., 2010). In the study, we investigated whether the SIMOA method could determine SARS-CoV-2 antigen levels in patients with COVID-19. The general characteristics of the patients enrolled in the study are presented in Table S1 in Supporting Information. The patients were aged 57.9 years. Among 35 patients, 15 (42.9%) were males, 11 (31.4%) had histories of staying in or traveling to Wuha n in 14 days before diagnosis, and 10 (28.6%) were severe or critically ill. Of the 10 severe or critically ill patients, five experienced ARDS.