Comparison of First and 21st Day anti SARS-CoV-2 anti-spike IgM and IgG Responses

Abstract

Objective: There is no definitive information yet about antibody kinetics produced in response to coronavirus disease-2019 (COVID-19) infection. It is essential to know the antibody levels in different patient groups. Our study compared the immunoglobulin M (IgM) and immunoglobulin (IgG) type antibody levels developed against COVID-19 infection by age groups and first-time complaints. Materials and Methods: IgM and IgG levels were investigated on the day of diagnosis and on the 21st day on serum samples with a point-of-care tests device in ninety-lbur COVID-19 patients. Antibody responses were evaluated according to age groups and clinical complaints. Results: First day IgM levels than 21st day and 21st day IgG levels than the first day were significantly higher (p=0.006, p<0.001, respectively). IgG on the first day and IgM on the 21st day was positive (>1). While IgG type antibody response was dominant in children, it was found that a robust antibody response occurred in young adults and over 65 years of age. Conclusion: Anti-spike severe acute respiratory syndrome-coronavirus-2 IgM antibodies remain positive for more extended periods, unlike known infectious agents, and measuring positive IgG values on the first day is insignificant in terms of protection against infection and appears specific to COVID-19. While IgG type antibodies dominate children, strong IgG and IgM type responses can be detected in young adults and the elderly. Different antibody responses may develop according to clinical findings.