摘要
The coronavirus disease 2019(COVID-19),caused by SARS-CoV-2,has spread around the world with high mortality.To diagnose promptly and accurately is the vital step to effectively control its pandemic.Dynamic characteristics of SARSCoV-2-specific antibodies which are important for diagnosis of infection have not been fully demonstrated.In this retrospective,single-center,observational study,we enrolled the initial 131 confirmed cases of COVID-19 at Jin-Yin-Tan Hospital who had at least one-time antibody tested during their hospitalization.The dynamic changes of IgM and IgG antibodies to SARS-CoV-2 nucleocapsid protein in 226 serum samples were detected by ELISA.The sensitivities of IgM and IgG ELISA detection were analyzed.Result showed that the sensitivity of the IgG ELISA detection(92.5%)was significantly higher than that of the IgM(70.8%)(P\0.001).The meantimes of seroconversion for IgM and IgG were6 days and 3 days,respectively.The IgM and IgG antibody levels peaked at around 18 days and 23 days,and then IgM fell to below the baseline level at about day 36,whereas IgG maintained at a relatively high level.In conclusion,antibodies should be detected to aid in diagnosis of COVID-19 infection.IgG could be a sensitive indicator for retrospective diagnosis and contact tracing,while IgM could be an indicator of early infection.
