tetano
Editor, Senior Moderator
Allergy
. 2020 Sep 30.
doi: 10.1111/all.14608. Online ahead of print.
Accuracy of serological testing for SARS-CoV-2 antibodies: first results of a large mixed-method evaluation study
D Brigger[SUP] 1 2 [/SUP], M P Horn[SUP] 3 [/SUP], L F Pennington[SUP] 4 [/SUP], A E Powell[SUP] 5 6 [/SUP], D Siegrist[SUP] 7 [/SUP], B Weber[SUP] 7 [/SUP], O Engler[SUP] 7 [/SUP], V Piezzi[SUP] 8 [/SUP], L Damonti[SUP] 8 [/SUP], P Iseli[SUP] 9 [/SUP], C Hauser[SUP] 8 [/SUP], T K Froehlich[SUP] 3 [/SUP], P M Villiger[SUP] 1 [/SUP], M F Bachmann[SUP] 1 2 [/SUP], S L Leib[SUP] 10 [/SUP], P Bittel[SUP] 10 [/SUP], M Fiedler[SUP] 3 [/SUP], C Largiad?r[SUP] 3 [/SUP], J Marschall[SUP] 8 [/SUP], H Stalder[SUP] 11 [/SUP], P S Kim[SUP] 5 6 [/SUP], T S Jardetzky[SUP] 4 [/SUP], A Eggel[SUP] 1 2 [/SUP], M Nagler[SUP] 2 [/SUP]
Affiliations
Abstract
Background: Serological immunoassays that can identify protective immunity against SARS-CoV-2 are needed to adapt quarantine measures, assess vaccination responses, and evaluate donor plasma. To date, however, the utility of such immunoassays remains unclear. In a mixed-design evaluation study, we compared the diagnostic accuracy of serological immunoassays that are based on various SARS-CoV-2 proteins and assessed the neutralizing activity of antibodies in patient sera.
Methods: Consecutive patients admitted with confirmed SARS-CoV-2 infection were prospectively followed alongside medical staff and biobank samples from winter 2018/2019. An in-house enzyme-linked immunosorbent assay utilizing recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike protein was developed and compared to three commercially available enzyme-linked immunosorbent assays (ELISAs) targeting the nucleoprotein (N), the S1 domain of the spike protein (S1) and a lateral flow immunoassay (LFI) based on full-length spike protein. Neutralization assays with live SARS-CoV-2 were performed.
Results: One-thousand four-hundred and seventy-seven individuals were included comprising 112 SARS-CoV-2 positives (defined as a positive real-time PCR result; prevalence 7.6%). IgG seroconversion occurred between day 0 and day 21. While the ELISAs showed sensitivities of 88.4% for RBD, 89.3% for S1, and 72.9% for N protein, the specificity was above 94% for all tests. Out of 54 SARS-CoV-2 positive individuals, 96.3% showed full neutralization of live SARS-CoV-2 at serum dilutions ≥1:16, while none of the 6 SARS-CoV-2 negative sera revealed neutralizing activity.
Conclusions: ELISAs targeting RBD and S1 protein of SARS-CoV-2 are promising immunoassays which shall be further evaluated in studies verifying diagnostic accuracy and protective immunity against SARS-CoV-2.
Keywords: Antibodies; COVID-19; COVID-19 diagnostic testing; Enzyme-Linked Immunosorbent Assay; Neutralizing; Severe Acute Respiratory Syndrome Coronavirus 2.
. 2020 Sep 30.
doi: 10.1111/all.14608. Online ahead of print.
Accuracy of serological testing for SARS-CoV-2 antibodies: first results of a large mixed-method evaluation study
D Brigger[SUP] 1 2 [/SUP], M P Horn[SUP] 3 [/SUP], L F Pennington[SUP] 4 [/SUP], A E Powell[SUP] 5 6 [/SUP], D Siegrist[SUP] 7 [/SUP], B Weber[SUP] 7 [/SUP], O Engler[SUP] 7 [/SUP], V Piezzi[SUP] 8 [/SUP], L Damonti[SUP] 8 [/SUP], P Iseli[SUP] 9 [/SUP], C Hauser[SUP] 8 [/SUP], T K Froehlich[SUP] 3 [/SUP], P M Villiger[SUP] 1 [/SUP], M F Bachmann[SUP] 1 2 [/SUP], S L Leib[SUP] 10 [/SUP], P Bittel[SUP] 10 [/SUP], M Fiedler[SUP] 3 [/SUP], C Largiad?r[SUP] 3 [/SUP], J Marschall[SUP] 8 [/SUP], H Stalder[SUP] 11 [/SUP], P S Kim[SUP] 5 6 [/SUP], T S Jardetzky[SUP] 4 [/SUP], A Eggel[SUP] 1 2 [/SUP], M Nagler[SUP] 2 [/SUP]
Affiliations
- PMID: 32997812
- DOI: 10.1111/all.14608
Abstract
Background: Serological immunoassays that can identify protective immunity against SARS-CoV-2 are needed to adapt quarantine measures, assess vaccination responses, and evaluate donor plasma. To date, however, the utility of such immunoassays remains unclear. In a mixed-design evaluation study, we compared the diagnostic accuracy of serological immunoassays that are based on various SARS-CoV-2 proteins and assessed the neutralizing activity of antibodies in patient sera.
Methods: Consecutive patients admitted with confirmed SARS-CoV-2 infection were prospectively followed alongside medical staff and biobank samples from winter 2018/2019. An in-house enzyme-linked immunosorbent assay utilizing recombinant receptor-binding domain (RBD) of the SARS-CoV-2 spike protein was developed and compared to three commercially available enzyme-linked immunosorbent assays (ELISAs) targeting the nucleoprotein (N), the S1 domain of the spike protein (S1) and a lateral flow immunoassay (LFI) based on full-length spike protein. Neutralization assays with live SARS-CoV-2 were performed.
Results: One-thousand four-hundred and seventy-seven individuals were included comprising 112 SARS-CoV-2 positives (defined as a positive real-time PCR result; prevalence 7.6%). IgG seroconversion occurred between day 0 and day 21. While the ELISAs showed sensitivities of 88.4% for RBD, 89.3% for S1, and 72.9% for N protein, the specificity was above 94% for all tests. Out of 54 SARS-CoV-2 positive individuals, 96.3% showed full neutralization of live SARS-CoV-2 at serum dilutions ≥1:16, while none of the 6 SARS-CoV-2 negative sera revealed neutralizing activity.
Conclusions: ELISAs targeting RBD and S1 protein of SARS-CoV-2 are promising immunoassays which shall be further evaluated in studies verifying diagnostic accuracy and protective immunity against SARS-CoV-2.
Keywords: Antibodies; COVID-19; COVID-19 diagnostic testing; Enzyme-Linked Immunosorbent Assay; Neutralizing; Severe Acute Respiratory Syndrome Coronavirus 2.