Abstract
Serologic point-of-care tests to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an important tool in the COVID-19 pandemic. The majority of current point-of-care antibody tests developed for SARS-CoV-2 rely on lateral flow assays, but these do not offer quantitative information. To address this, we developed a novel antibody test leveraging hemagglutination, employing a dry card format currently used for typing ABO blood groups. Two hundred COVID-19 patient and 200 control plasma samples were reconstituted with O-negative red blood cells (RBCs) to form whole blood and added to dried viral-antibody fusion protein, followed by a stirring step and a tilting step, 3-min incubation, and a second tilting step. The sensitivities of the hemagglutination test, Euroimmun IgG enzyme-linked immunosorbent assay (ELISA), and receptor binding domain (RBD)-based CoronaChek lateral flow assay were 87.0%, 86.5%, and 84.5%, respectively, using samples obtained from recovered COVID-19 individuals. Testing prepandemic samples, the hemagglutination test had a specificity of 95.5%, compared to 97.3% and 98.9% for the ELISA and CoronaChek, respectively. A distribution of agglutination strengths was observed in COVID-19 convalescent-phase plasma samples, with the highest agglutination score (4) exhibiting significantly higher neutralizing antibody titers than weak positives (2) ( P < 0.0001). Strong agglutinations were observed within 1 min of testing, and this shorter assay time also increased specificity to 98.5%. In conclusion, we developed a novel rapid, point-of-care RBC agglutination test for the detection of SARS-CoV-2 antibodies that can yield semiquantitative information on neutralizing antibody titer in patients. The 5-min test may find use in determination of serostatus prior to vaccination, postvaccination surveillance, and travel screening.
Keywords: SARS-CoV-2; antibody; hemagglutination; point of care; red blood cell; serology.
【저자키워드】 SARS-CoV-2, antibody, point of care, Serology., hemagglutination, red blood cell, 【초록키워드】 COVID-19, IgG, coronavirus, vaccination, serology, antibody, COVID-19 pandemic, severe acute respiratory syndrome Coronavirus, ELISA, Receptor binding domain, lateral flow, point-of-care, sensitivity, specificity, enzyme-linked immunosorbent assay, Testing, SARS-CoV-2 antibodies, SARS-CoV-2 antibody, Surveillance, Whole blood, serologic, antibody tests, Travel, Antibody titer, Blood groups, red blood cells, Antibody test, point-of-care test, fusion protein, respiratory, distribution, information, serostatus, Euroimmun, Quantitative, patients, Blood, Antibody titers, Neutralizing antibody titer, hemagglutination, red blood cell, ABO, COVID-19 patient, followed by, blood cell, agglutination test, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, plasma samples, sensitivities, positive, offer, RBCs, postvaccination, RBC, enzyme-linked immunosorbent, plasma sample, highest, detect, assays, added, majority, significantly higher, individuals, groups, exhibiting, Strong, 【제목키워드】 Test, Level, Determination,