Can measuring patients’ antibodies be helpful in early diagnosis of COVID-19?

Bottom Line:

Measuring two kinds of antibodies (IgG and IgM) may be useful in early COVID-19 diagnosis.


Zhang, G. et al. Longitudinal Change of SARS-Cov2 Antibodies in Patients with COVID-19. Journal of Infectious Diseases (2020). DOI: 10.1093/infdis/jiaa229

Date Published:

2 May 2020


Antibodies are immune molecules in our bodies that form against a specific recognizable target, or antigen. Our bodies identify this antigen target as being “foreign” and make antibodies to protect ourselves against it in case it is detected again. There exists different kinds of antibodies which have specific roles in immunity, for example IgM and IgG antibodies. This study recruited patients diagnosed with COVID-19. Most patients tested positive for both kinds of antibodies against COVID-19. However, some patients only tested positive for one kind antibody. Meanwhile, a minority of patients were negative for both antibodies. IgM antibodies were detectable within one week of disease onset, whereas IgG antibodies were detectable starting at 10 days after infection. Thus, these antibodies have clinical utility in early diagnosis of infection.

Summary by: Jackie Tsang