Are anti-SARS-CoV-2 S/N IgG/IgM antibodies always predictive of previous SARS-CoV-2 infection?

© 2023 the author(s), published by De Gruyter, Berlin/Boston..

Objectives: We planned this study to verify whether immunoassays for quantifying anti-SARS-CoV-2 IgG/IgM antibodies against both spike (S) and nucleocapsid (N) proteins may be used for identifying previous SARS-CoV-2 infections.

Methods: The study population consisted of a cohort of fully vaccinated healthcare workers. All study subjects underwent regular medical visits and molecular testing for diagnosing SARS-CoV-2 infections every 2-4 weeks between 2020-2022. Venous blood was drawn for measuring anti-SARS-CoV-2 antibodies with MAGLUMI 2019-nCoV lgG/IgM CLIA Assays directed against both SARS-CoV-2 S and N proteins.

Results: Overall, 31/53 (58.5%) subjects had tested positive for SARS-CoV-2 by RT-PCR throughout the study (24 once, 7 twice). No positive correlation was found between anti-SARS-CoV-2 S/N IgM antibodies and molecular test positivity. In univariate regression analysis, both a molecular test positivity (r=0.33; p=0.015) and the number of positive molecular tests (r=0.43; p=0.001), but not vaccine doses (r=-0.12; p=0.392), were significantly correlated with anti-SARS-CoV-2 S/N IgG antibodies. These two associations remained significant in multiple linear regression analysis (p=0.029 and p<0.001, respectively) after adjusting for sex, age, body mass index, and vaccine doses. In ROC curve analysis, anti-SARS-CoV-2 S/N IgG antibodies significantly predicted molecular test positivity (AUC, 0.69; 95% CI; 0.55-0.84), with the best cutoff of 0.05 AU/mL displaying 67.9% accuracy, 0.97 sensitivity, and 0.27 specificity.

Conclusions: Although anti-SARS-CoV-2 S/N IgG antibodies provide helpful information for identifying previous SARS-CoV-2 infections, a lower cutoff than that of sample reactivity should be used. Anti-SARS-CoV-2 S/N IgM antibodies using conventional cutoffs seem useless for this purpose.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:4

Enthalten in:

Advances in laboratory medicine - 4(2023), 2 vom: 01. Juni, Seite 175-184

Sprache:

Englisch

Beteiligte Personen:

Lippi, Giuseppe [VerfasserIn]
Henry, Brandon M [VerfasserIn]
Pighi, Laura [VerfasserIn]
De Nitto, Simone [VerfasserIn]
Salvagno, Gian Luca [VerfasserIn]

Links:

Volltext

Themen:

Antibodies
COVID-19
Infection
Journal Article
SARS-CoV-2
Serology

Anmerkungen:

Date Revised 05.04.2024

published: Electronic-eCollection

Citation Status PubMed-not-MEDLINE

doi:

10.1515/almed-2023-0008

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM365667498