Diagnostic Accuracy of a Laboratory-Developed IgG Anti-RBD ELISA to Detect Neutralizing Antibodies
| Source . | Number . | Reference Standard . | Cutoff for Positivitya . | TP . | FP . | FN . | TN . | Sensitivity . | Specificity . |
|---|---|---|---|---|---|---|---|---|---|
| National Microbiology Laboratory panel no. 1b (Canada) | 20 (+)/20 (−) | WT PRNT-50 | 1:20 | 19 | 1 | 0 | 20 | 100 (82–100) | 95 (76–100) |
| 1:50 | 18 | 2 | 0 | 20 | 100 (81–100) | 91 (71–99) | |||
| WT PRNT-90 | 1:20 | 7 | 13 | 0 | 20 | 100 (59–100) | 61 (42–77) | ||
| 1:50 | 5 | 15 | 0 | 20 | 100 (48–100) | 57 (39–74) | |||
| PLV ID50 | 1:50 | 12 | 8 | 1 | 19 | 92 (64–100) | 70 (50–86) | ||
| PLV ID80 | 1:50 | 10 | 10 | 0 | 20 | 100 (69–100) | 67 (47–83) | ||
| National Microbiology Laboratory panel no. 2b (Canada) | 60 (+)/21 (−) | WT PRNT-50 | 1:20 | 59 | 0 | 1 | 21 | 98 (91–100) | 100 (84–100) |
| 1:50 | 57 | 2 | 1 | 21 | 98 (91–100) | 91 (72–99) | |||
| PLV ID50 | 1:50 | 25 | 34 | 0 | 22 | 100 (86–100) | 39 (26–53) | ||
| HQ blood bank -convalescent plasma donors with longitudinal follow-upc | 15 patients, 6 weeks postsymptom onset | PLV ID50 | 1:50 | 10 | 3 | 0 | 2 | 100 (69–100) | 40 (5–85) |
| 14 patients, 10 weeks postsymptom onset | PLV ID50 | 1:50 | 8 | 6 | 0 | 0 | 100 (63–100) | 0 (0–46) | |
| HQ blood bank -convalescent plasma donors with single time point follow-upc | 50 patients, any time postsymptom onset | PLV ID50 | 1:50 | 28 | 22 | 0 | 0 | 100 (88–100) | 0 (0–15) |
| 0–6 weeks postsymptom onset | 12 | 6 | 0 | 0 | 100 (74–100) | 0 (0–46) | |||
| >6 weeks postsymptom onset | 16 | 16 | 0 | 0 | 100 (79–100) | 0 (0–21) | |||
| Overall (vs PLV ID50) | 1:50 | 83 | 73 | 1 | 43 | 99 (94–100) | 37 (28–47) |
| Source . | Number . | Reference Standard . | Cutoff for Positivitya . | TP . | FP . | FN . | TN . | Sensitivity . | Specificity . |
|---|---|---|---|---|---|---|---|---|---|
| National Microbiology Laboratory panel no. 1b (Canada) | 20 (+)/20 (−) | WT PRNT-50 | 1:20 | 19 | 1 | 0 | 20 | 100 (82–100) | 95 (76–100) |
| 1:50 | 18 | 2 | 0 | 20 | 100 (81–100) | 91 (71–99) | |||
| WT PRNT-90 | 1:20 | 7 | 13 | 0 | 20 | 100 (59–100) | 61 (42–77) | ||
| 1:50 | 5 | 15 | 0 | 20 | 100 (48–100) | 57 (39–74) | |||
| PLV ID50 | 1:50 | 12 | 8 | 1 | 19 | 92 (64–100) | 70 (50–86) | ||
| PLV ID80 | 1:50 | 10 | 10 | 0 | 20 | 100 (69–100) | 67 (47–83) | ||
| National Microbiology Laboratory panel no. 2b (Canada) | 60 (+)/21 (−) | WT PRNT-50 | 1:20 | 59 | 0 | 1 | 21 | 98 (91–100) | 100 (84–100) |
| 1:50 | 57 | 2 | 1 | 21 | 98 (91–100) | 91 (72–99) | |||
| PLV ID50 | 1:50 | 25 | 34 | 0 | 22 | 100 (86–100) | 39 (26–53) | ||
| HQ blood bank -convalescent plasma donors with longitudinal follow-upc | 15 patients, 6 weeks postsymptom onset | PLV ID50 | 1:50 | 10 | 3 | 0 | 2 | 100 (69–100) | 40 (5–85) |
| 14 patients, 10 weeks postsymptom onset | PLV ID50 | 1:50 | 8 | 6 | 0 | 0 | 100 (63–100) | 0 (0–46) | |
| HQ blood bank -convalescent plasma donors with single time point follow-upc | 50 patients, any time postsymptom onset | PLV ID50 | 1:50 | 28 | 22 | 0 | 0 | 100 (88–100) | 0 (0–15) |
| 0–6 weeks postsymptom onset | 12 | 6 | 0 | 0 | 100 (74–100) | 0 (0–46) | |||
| >6 weeks postsymptom onset | 16 | 16 | 0 | 0 | 100 (79–100) | 0 (0–21) | |||
| Overall (vs PLV ID50) | 1:50 | 83 | 73 | 1 | 43 | 99 (94–100) | 37 (28–47) |
Abbreviations: anti-S-RBD, antibodies against receptor binding domain of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) spike protein; ELISA, enzyme-linked immunosorbent assay; FN, false negative; FP, false positive; HQ, Héma-Québec; PRNT, plaque-reduction neutralization test; TN, true negative; TP, true positive; WT, wild type.
aCutoff used to determine immunoglobulin (Ig)G anti-RBD ELISA positivity was ≥4.335.
b(+) denotes serological specimens positive by SARS-CoV-2 polymerase chain reaction (PCR) and (−) denotes serological specimens negative by SARS-CoV-2 PCR but positive for related infections.
cFrom patients meeting public health case definitions of coronavirus disease 2019 (COVID-19), with either nucleic acid amplification test-confirmed SARS CoV-2 infection or an epidemiological link to a known case of COVID-19 (SARS CoV-2 infection). Specimens characterized by anti-S-RBD ELISA and PLV ID50.
NOTE: WT PRNT-50 or PRNT-90 denotes neutralization titers required for a 50% or 90% plaque reduction, respectively, using SARS-CoV-2 viral culture; PLV ID50 or PLV ID80 denotes the serum dilution to inhibit 50% or 80% of the infection of 293T-ACE2 cells by recombinant viruses bearing the indicated surface glycoproteins.
Diagnostic Accuracy of a Laboratory-Developed IgG Anti-RBD ELISA to Detect Neutralizing Antibodies
| Source . | Number . | Reference Standard . | Cutoff for Positivitya . | TP . | FP . | FN . | TN . | Sensitivity . | Specificity . |
|---|---|---|---|---|---|---|---|---|---|
| National Microbiology Laboratory panel no. 1b (Canada) | 20 (+)/20 (−) | WT PRNT-50 | 1:20 | 19 | 1 | 0 | 20 | 100 (82–100) | 95 (76–100) |
| 1:50 | 18 | 2 | 0 | 20 | 100 (81–100) | 91 (71–99) | |||
| WT PRNT-90 | 1:20 | 7 | 13 | 0 | 20 | 100 (59–100) | 61 (42–77) | ||
| 1:50 | 5 | 15 | 0 | 20 | 100 (48–100) | 57 (39–74) | |||
| PLV ID50 | 1:50 | 12 | 8 | 1 | 19 | 92 (64–100) | 70 (50–86) | ||
| PLV ID80 | 1:50 | 10 | 10 | 0 | 20 | 100 (69–100) | 67 (47–83) | ||
| National Microbiology Laboratory panel no. 2b (Canada) | 60 (+)/21 (−) | WT PRNT-50 | 1:20 | 59 | 0 | 1 | 21 | 98 (91–100) | 100 (84–100) |
| 1:50 | 57 | 2 | 1 | 21 | 98 (91–100) | 91 (72–99) | |||
| PLV ID50 | 1:50 | 25 | 34 | 0 | 22 | 100 (86–100) | 39 (26–53) | ||
| HQ blood bank -convalescent plasma donors with longitudinal follow-upc | 15 patients, 6 weeks postsymptom onset | PLV ID50 | 1:50 | 10 | 3 | 0 | 2 | 100 (69–100) | 40 (5–85) |
| 14 patients, 10 weeks postsymptom onset | PLV ID50 | 1:50 | 8 | 6 | 0 | 0 | 100 (63–100) | 0 (0–46) | |
| HQ blood bank -convalescent plasma donors with single time point follow-upc | 50 patients, any time postsymptom onset | PLV ID50 | 1:50 | 28 | 22 | 0 | 0 | 100 (88–100) | 0 (0–15) |
| 0–6 weeks postsymptom onset | 12 | 6 | 0 | 0 | 100 (74–100) | 0 (0–46) | |||
| >6 weeks postsymptom onset | 16 | 16 | 0 | 0 | 100 (79–100) | 0 (0–21) | |||
| Overall (vs PLV ID50) | 1:50 | 83 | 73 | 1 | 43 | 99 (94–100) | 37 (28–47) |
| Source . | Number . | Reference Standard . | Cutoff for Positivitya . | TP . | FP . | FN . | TN . | Sensitivity . | Specificity . |
|---|---|---|---|---|---|---|---|---|---|
| National Microbiology Laboratory panel no. 1b (Canada) | 20 (+)/20 (−) | WT PRNT-50 | 1:20 | 19 | 1 | 0 | 20 | 100 (82–100) | 95 (76–100) |
| 1:50 | 18 | 2 | 0 | 20 | 100 (81–100) | 91 (71–99) | |||
| WT PRNT-90 | 1:20 | 7 | 13 | 0 | 20 | 100 (59–100) | 61 (42–77) | ||
| 1:50 | 5 | 15 | 0 | 20 | 100 (48–100) | 57 (39–74) | |||
| PLV ID50 | 1:50 | 12 | 8 | 1 | 19 | 92 (64–100) | 70 (50–86) | ||
| PLV ID80 | 1:50 | 10 | 10 | 0 | 20 | 100 (69–100) | 67 (47–83) | ||
| National Microbiology Laboratory panel no. 2b (Canada) | 60 (+)/21 (−) | WT PRNT-50 | 1:20 | 59 | 0 | 1 | 21 | 98 (91–100) | 100 (84–100) |
| 1:50 | 57 | 2 | 1 | 21 | 98 (91–100) | 91 (72–99) | |||
| PLV ID50 | 1:50 | 25 | 34 | 0 | 22 | 100 (86–100) | 39 (26–53) | ||
| HQ blood bank -convalescent plasma donors with longitudinal follow-upc | 15 patients, 6 weeks postsymptom onset | PLV ID50 | 1:50 | 10 | 3 | 0 | 2 | 100 (69–100) | 40 (5–85) |
| 14 patients, 10 weeks postsymptom onset | PLV ID50 | 1:50 | 8 | 6 | 0 | 0 | 100 (63–100) | 0 (0–46) | |
| HQ blood bank -convalescent plasma donors with single time point follow-upc | 50 patients, any time postsymptom onset | PLV ID50 | 1:50 | 28 | 22 | 0 | 0 | 100 (88–100) | 0 (0–15) |
| 0–6 weeks postsymptom onset | 12 | 6 | 0 | 0 | 100 (74–100) | 0 (0–46) | |||
| >6 weeks postsymptom onset | 16 | 16 | 0 | 0 | 100 (79–100) | 0 (0–21) | |||
| Overall (vs PLV ID50) | 1:50 | 83 | 73 | 1 | 43 | 99 (94–100) | 37 (28–47) |
Abbreviations: anti-S-RBD, antibodies against receptor binding domain of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) spike protein; ELISA, enzyme-linked immunosorbent assay; FN, false negative; FP, false positive; HQ, Héma-Québec; PRNT, plaque-reduction neutralization test; TN, true negative; TP, true positive; WT, wild type.
aCutoff used to determine immunoglobulin (Ig)G anti-RBD ELISA positivity was ≥4.335.
b(+) denotes serological specimens positive by SARS-CoV-2 polymerase chain reaction (PCR) and (−) denotes serological specimens negative by SARS-CoV-2 PCR but positive for related infections.
cFrom patients meeting public health case definitions of coronavirus disease 2019 (COVID-19), with either nucleic acid amplification test-confirmed SARS CoV-2 infection or an epidemiological link to a known case of COVID-19 (SARS CoV-2 infection). Specimens characterized by anti-S-RBD ELISA and PLV ID50.
NOTE: WT PRNT-50 or PRNT-90 denotes neutralization titers required for a 50% or 90% plaque reduction, respectively, using SARS-CoV-2 viral culture; PLV ID50 or PLV ID80 denotes the serum dilution to inhibit 50% or 80% of the infection of 293T-ACE2 cells by recombinant viruses bearing the indicated surface glycoproteins.
This PDF is available to Subscribers Only
View Article Abstract & Purchase OptionsFor full access to this pdf, sign in to an existing account, or purchase an annual subscription.
