Table 1.
Characteristics and performance of six anti-SARS-CoV-2 antibody test kits.
| Test kit |
Sensitivity | Specificity | PPV | NPV | Sensitivity + specificity | |||
|---|---|---|---|---|---|---|---|---|
| Method | Manufacturer | Target protein | Target antibody | |||||
| RDT using gold conjugate | SD Biosensora | NCP | IgM | 78.9 | 98.3 | 97.7 | 83.6 | 177.2 |
| IgG | 94.5 | 96.6 | 96.3 | 95.0 | 191.2 | |||
| IgM or IgG | 99.1 | 95.0 | 94.7 | 99.1 | 194.0 | |||
| FIA using europium particles | SD Biosensor | NCP | IgM | 74.5 | 93.3 | 91.1 | 79.9 | 167.8 |
| IgG | 97.3 | 94.1 | 93.9 | 97.4 | 191.4 | |||
| IgM or IgG | 99.1 | 87.4 | 87.9 | 99.0 | 186.5 | |||
| Boditech Med | NCP | IgM | 14.5 | 99.2 | 94.1 | 55.7 | 113.7 | |
| IgG | 99.1 | 94.1 | 94.0 | 99.1 | 193.2 | |||
| IgM or IgG | 99.1 | 93.3 | 93.2 | 99.1 | 192.4 | |||
| ELISA | SD Biosensorb | RBD & NCP | Total antibody | 96.3 | 100.0 | 100.0 | 96.7 | 196.3 |
| PCL | RBD & NCP | Total antibody | 98.2 | 100.0 | 100.0 | 98.3 | 198.2 | |
| EUROIMMUNc | RBD | IgG, OD ratio ≥0.8d | 95.4 | 96.6 | 96.3 | 95.8 | 192.1 | |
| IgG, OD ratio ≥1.1 | 93.5 | 100.0 | 100.0 | 94.4 | 193.5 | |||
A total of 110 RT-PCR confirmed positive specimens and 119 negative control specimens were used, otherwise indicated.
Abbreviations: SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; PPV, positive predictive value; NPV, negative predictive value; RDT, rapid diagnostic kit; FIA, fluorescence immunoassay; ELISA, enzyme-linked immunosorbent assay; NCP, nucleocapsid protein; RBD, receptor binding domain; COI, cut-off index; OD, optical density.
a
109 positive specimens were used.
b
108 positive specimens and 118 negative control specimens were used.
c
108 positive specimens and 117 negative control specimens were used.
d
Cut-off value for the borderline result.