Diagnostic Properties of Three SARS-CoV-2 Antibody Tests

• Published in: Diagnostics (Basel) Vol. 11; no. 8; p. 1441
• Main Authors: Basgalupp, Suelen, dos Santos, Giovana, Bessel, Marina, Garcia, Lara, de Moura, Ana Carolina, Rocha, Ana Carolina, Brito, Emerson, de Miranda, Giovana, Dornelles, Thayane, Dartora, William, Pellanda, Lucia, Hallal, Pedro, Wendland, Eliana
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 10-08-2021; MDPI
• Subjects: Antibodies; Antigens; Asymptomatic; Coronaviruses; COVID-19; ELISA; Enzymes; Immunoassay; Infections; Pandemics; point-of-care test; Proteins; SARS-CoV-2; serological tests; Serology; Severe acute respiratory syndrome coronavirus 2; Statistical analysis; United States > US
• ISSN: 2075-4418; 2075-4418
• DOI: 10.3390/diagnostics11081441

Serological assays emerged as complementary tools to RT-PCR in the diagnosis of SARS-CoV-2 as well as being needed for epidemiological studies. This study aimed to assess the performance of a rapid test (RT) compared to that of serological tests using finger prick blood samples. A total of 183 samples were evaluated, 88 of which were collected from individuals with negative RT-PCR and 95 from positive RT-PCR individuals. The diagnostic performance of RT (WONDFO®) and LUMIT (PROMEGA®) were compared to that of ELISA (EUROIMMUN®) for detecting antibodies against SARS-CoV-2 according to time from symptoms onset. The IgG antibody tests were detected in 77.4% (LUMIT), 77.9% (RT), and 80.0% (ELISA) of individuals. The detection of antibodies against SARS-CoV-2 increases in accordance with increasing time from symptoms onset. Considering only time from symptoms onset >21 days, the positivity rate ranged from 81.8 to 97.0% between the three tests. The RT and LUMIT showed high agreement with ELISA (agreement = 91.5%, k = 0.83, and agreement = 96.3%, k = 0.9, respectively) in individuals who had symptoms 15 to 21 days before sample collection. Compared to that of the ELISA assay, our results show sensitivity ranged from 95% to 100% for IgG antibody detection in individuals with symptoms onset between 15 and 21 days before sample collection. The specificity was 100% in individuals with symptoms onset >15 days before serological tests. This study shows good performance and high level of agreement of three immunoassays for the detection of SARS-CoV-2 antibodies.