Abstract
Objectives: This study intended to investigate the dynamics of anti-spike (S) IgG and IgM antibodies in COVID-19 patients.
Methods: Anti-S IgG/IgM was determined by a semi-quantitative fluorescence immunoassay in the plasma of COVID-19 patients at the manifestation and rehabilitation stages. The immunoreactivity to full-length S proteins, C-terminal domain (CTD), and N-terminal domain (NTD) of S1 fragments were determined by an ELISA assay. Clinical properties at admission and discharge were collected simultaneously.
Results: The positive rates of anti-S IgG/IgM in COVID-19 patients were elevated after rehabilitation compared to the in-patients. Anti-S IgG and IgM were not apparent until day 14 and day ten, respectively, according to Simple Moving Average analysis with five days’ slide window deduction. More than 90% of the rehabilitation patients exhibited IgG and IgM responses targeting CTD-S1 fragments. Decreased total peripheral lymphocytes, CD4 + and CD8 + T cell counts were seen in COVID-19 patients at admission and recovered after the rehabilitation.
Conclusions: Anti-S IgG and IgM do not appear at the onset with the decrease in T cells, making early serological screening less significant. However, the presence of high IgG and IgM to S1-CTD in the recovered patients highlights humoral responses after SARS-CoV-2 infection, which might be associated with efficient immune protection in COVID-19 patients.
Keywords: COVID-19; Dynamics; IgG and IgM; SARS-CoV-2; Spike glycoprotein.
【저자키워드】 COVID-19, SARS-CoV-2, Dynamics, spike glycoprotein, IgG and IgM, 【초록키워드】 IgG, Lymphocytes, spike, antibody, T cells, SARS-COV-2 infection, rehabilitation, Proteins, CD4, CD8, discharge, immunoassay, T cell, Humoral response, clinical, response, plasma, NTD, glycoprotein, serological, Admission, positive rate, COVID-19 patients, ELISA assay, Anti-spike, immune protection, N-terminal domain, C-terminal domain, Analysis, COVID-19 patient, In-patients, stages, immunoreactivity, anti-S, simple, full-length S, FIVE, decrease, highlight, recovered patient, collected, elevated, exhibited, was determined, less, semi-quantitative, CTD, Decreased, rehabilitation patient, 【제목키워드】 antibody, Protein, Anti-spike, COVID-19 patient, profile, dynamic,