A High-throughput Anti-SARS-CoV-2 IgG Testing Platform for COVID-19

Du, Jinwei; Chu, Eric; Zhang, Dayu; Lu, Chuanyi M.; Zhang, Aiguo; Sha, Michael Y.

BACKGROUND: Serology tests for detecting the antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can identify previous infection and help to confirm the presence of current infection. OBJECTIVE: The aim of this study was to evaluate the performances of a newly developed high throughput immunoassay for anti-SARS-CoV-2 IgG antibody detection. RESULTS: Clinical agreement studies were performed in 107 COVID-19 patient serum samples and 226 negative donor serum/plasma samples. Positive percent agreement (PPA) was 46.15% (95% CI: 19.22% ∼74.87%), 61.54% (95% CI: 31.58% ∼86.14%), and 97.53% (95% CI: 91.36% ∼99.70%) for samples collected on 0-7 days, 8-14 days, and ≥15 days from symptom onset, respectively. Negative Percent Agreement (NPA) was 98.23% (95% CI: 95.53% ∼99.52%). No cross-reactivity was observed to patient samples positive for IgG antibodies against the following pathogens: HIV, HAV, HBV, RSV, CMV, EBV, Rubella, Influenza A, and Influenza B. Hemoglobin (200 mg/dL), bilirubin (2 mg/dL) and EDTA (10 mM) showed no significant interfering effect on this assay. CONCLUSION: An anti-SARS-CoV-2 IgG antibody assay with high sensitivity and specificity has been developed. With the high throughput, this assay will speed up anti-SARS-CoV-2 IgG testing.