Abstract
The aim of this study was to develop the first quantitative serological test for anti-SARS-CoV-2 antibodies in human serum with liquid chromatography – quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Other assays, mostly immunoassays, are only qualitative or semi-quantitative, and hence, actual antibody concentrations after SARS-CoV-2 infection are unknown. In our assay, anti-SARS-CoV-2 antibodies were isolated with spike protein subunit 1 (S1) coupled to magnetic beads. IgG1 signature peptide GPSVFPLAPSSK was selected for quantification using ipilimumab calibration standards and SILuMAb K1 as the stable-isotope labeled internal standard. The anti-SARS-CoV-2 IgG1 calibration range was from 1.35 to 135 nM. Inter-assay accuracies were between 98.8%- 107% with inter-assay precisions between 8.37%- 13.5% measured at 3 concentration levels on three separate occasions. Anti-SARS-CoV-2 IgG1 antibodies were quantified in PCR-positive patients with mild to severe symptoms. IgM signature peptide DGFFGVPR was detected in patients that recently recovered from COVID-19. A unique and quantitative LC-QTOF-MS method to quantify anti-SARS-CoV-2 IgG1 in serum was successfully developed and its clinical applicability has been demonstrated.
Keywords: Anti-SARS-CoV-2 antibodies; COVID-19; LC-QTOF-MS; Mass spectrometry; SARS-CoV-2; Spike protein.
【저자키워드】 COVID-19, SARS-CoV-2, mass spectrometry, Spike protein, anti-SARS-CoV-2 antibodies, LC-QTOF-MS, 【초록키워드】 serological test, IgM, mass spectrometry, spike, SARS-COV-2 infection, peptide, anti-SARS-CoV-2, Spike protein, immunoassays, Protein, serum, anti-SARS-CoV-2 antibodies, Liquid chromatography, anti-SARS-CoV-2 antibody, Accuracy, Patient, Mild, quantification, Other, Quantitative, human serum, IgG1, Concentration, Magnetic beads, antibody concentration, Precision, subunit, mass, severe symptoms, Ipilimumab, applicability, flight, anti-SARS-CoV-2 IgG1, IgG1 antibodies, develop, assays, unique, demonstrated, semi-quantitative, quantified, IgG1 antibody, PCR-positive patient, was selected, 【제목키워드】 anti-SARS-CoV-2 antibody,