tetano
Editor, Senior Moderator
Eur J Clin Microbiol Infect Dis
. 2021 Jun 9.
doi: 10.1007/s10096-021-04285-4. Online ahead of print.
Diagnostic performance of four SARS-CoV-2 antibody assays in patients with COVID-19 or with bacterial and non-SARS-CoV-2 viral respiratory infections
Timo Huber[SUP] 1 [/SUP], Philipp Steininger[SUP] 2 [/SUP], Pascal Irrgang[SUP] 2 [/SUP], Klaus Korn[SUP] 2 [/SUP], Matthias Tenbusch[SUP] 2 [/SUP], Katharina Diesch[SUP] 3 [/SUP], Susanne Achenbach[SUP] 4 [/SUP], Andreas E Kremer[SUP] 5 [/SUP], Marissa Werblow[SUP] 1 [/SUP], Marcel Vetter[SUP] 5 [/SUP], Christian Bogdan[SUP] 1 6 [/SUP], Jürgen Held[SUP] 7 [/SUP]
Affiliations
Abstract
SARS-CoV-2 antibody assays are used for epidemiological studies and for the assessment of vaccine responses in highly vulnerable patients. So far, data on cross-reactivity of SARS-CoV-2 antibody assays is limited. Here, we compared four enzyme-linked immunosorbent assays (ELISAs; Vircell SARS-CoV-2 IgM/IgA and IgG, Euroimmun SARS-CoV-2 IgA and IgG) for detection of anti-SARS-CoV-2 antibodies in 207 patients with COVID-19, 178 patients with serological evidence of different bacterial infections, 107 patients with confirmed viral respiratory disease, and 80 controls from the pre-COVID-19 era. In COVID-19 patients, the assays showed highest sensitivity in week 3 (Vircell-IgM/A and Euroimmun-IgA: 78.9% each) and after week 7 (Vircell-IgG: 97.9%; Euroimmun-IgG: 92.1%). The antibody indices were higher in patients with fatal disease. In general, IgM/IgA assays had only limited or no benefit over IgG assays. In patients with non-SARS-CoV-2 respiratory infections, IgG assays were more specific than IgM/IgA assays, and bacterial infections were associated with more false-positive results than viral infections. The specificities in bacterial and viral infections were 68.0 and 81.3% (Vircell-IgM/IgA), 84.8 and 96.3% (Euroimmun-IgA), 97.8 and 86.0% (Vircell-IgG), and 97.8 and 99.1% (Euroimmun-IgG), respectively. Sera from patients positive for antibodies against Mycoplasma pneumoniae, Chlamydia psittaci, and Legionella pneumophila yielded particularly high rates of unspecific false-positive results in the IgM/IgA assays, which was revealed by applying a highly specific flow-cytometric assay using HEK 293 T cells expressing the SARS-CoV-2 spike protein. Positive results obtained with anti-SARS-CoV-2 IgM/IgA ELISAs require careful interpretation, especially if there is evidence for prior bacterial respiratory infections.
Keywords: Antibody; Bacterial infections; COVID-19; Coronavirus; Euroimmun; SARS-CoV-2; Vircell
. 2021 Jun 9.
doi: 10.1007/s10096-021-04285-4. Online ahead of print.
Diagnostic performance of four SARS-CoV-2 antibody assays in patients with COVID-19 or with bacterial and non-SARS-CoV-2 viral respiratory infections
Timo Huber[SUP] 1 [/SUP], Philipp Steininger[SUP] 2 [/SUP], Pascal Irrgang[SUP] 2 [/SUP], Klaus Korn[SUP] 2 [/SUP], Matthias Tenbusch[SUP] 2 [/SUP], Katharina Diesch[SUP] 3 [/SUP], Susanne Achenbach[SUP] 4 [/SUP], Andreas E Kremer[SUP] 5 [/SUP], Marissa Werblow[SUP] 1 [/SUP], Marcel Vetter[SUP] 5 [/SUP], Christian Bogdan[SUP] 1 6 [/SUP], Jürgen Held[SUP] 7 [/SUP]
Affiliations
- PMID: 34109500
- DOI: 10.1007/s10096-021-04285-4
Abstract
SARS-CoV-2 antibody assays are used for epidemiological studies and for the assessment of vaccine responses in highly vulnerable patients. So far, data on cross-reactivity of SARS-CoV-2 antibody assays is limited. Here, we compared four enzyme-linked immunosorbent assays (ELISAs; Vircell SARS-CoV-2 IgM/IgA and IgG, Euroimmun SARS-CoV-2 IgA and IgG) for detection of anti-SARS-CoV-2 antibodies in 207 patients with COVID-19, 178 patients with serological evidence of different bacterial infections, 107 patients with confirmed viral respiratory disease, and 80 controls from the pre-COVID-19 era. In COVID-19 patients, the assays showed highest sensitivity in week 3 (Vircell-IgM/A and Euroimmun-IgA: 78.9% each) and after week 7 (Vircell-IgG: 97.9%; Euroimmun-IgG: 92.1%). The antibody indices were higher in patients with fatal disease. In general, IgM/IgA assays had only limited or no benefit over IgG assays. In patients with non-SARS-CoV-2 respiratory infections, IgG assays were more specific than IgM/IgA assays, and bacterial infections were associated with more false-positive results than viral infections. The specificities in bacterial and viral infections were 68.0 and 81.3% (Vircell-IgM/IgA), 84.8 and 96.3% (Euroimmun-IgA), 97.8 and 86.0% (Vircell-IgG), and 97.8 and 99.1% (Euroimmun-IgG), respectively. Sera from patients positive for antibodies against Mycoplasma pneumoniae, Chlamydia psittaci, and Legionella pneumophila yielded particularly high rates of unspecific false-positive results in the IgM/IgA assays, which was revealed by applying a highly specific flow-cytometric assay using HEK 293 T cells expressing the SARS-CoV-2 spike protein. Positive results obtained with anti-SARS-CoV-2 IgM/IgA ELISAs require careful interpretation, especially if there is evidence for prior bacterial respiratory infections.
Keywords: Antibody; Bacterial infections; COVID-19; Coronavirus; Euroimmun; SARS-CoV-2; Vircell