Abstract:

Objective To investigate the roles of severe acute respiratory syndrome coronavirus 2（SARS-CoV-2） immunoglobulin（Ig） M and IgG antibodies in corona virus disease 2019（COVID-19）. Methods A total of 80 patients with COVID-19 were enrolled,and 20 patients without COVID-19 were enrolled as control group. Immunochromatography was used to determine SARS-CoV-2 IgM and IgG antibodies. A total of 23 samples from COVID-19 patients were collected at different time points for the determination of SARS-CoV-2 antibodies. Results The specificities of SARS-CoV-2 IgM antibody,IgG antibody and IgM+IgG antibodies were all 100%,and the sensitivities were 76.3%,81.3% and 90.0%,respectively. The overall consistency rates were 81.0%,85.0% and 92.0%,respectively. Within 7 d of onset,the sensitivities of SARS-CoV-2 IgM antibody,IgG antibody and IgM+IgG antibodies were 65.0%,70.0% and 70.0%,on 8-14 d of onset,the sensitivities were 72.7 %,95.5% and 95.5%,and after 15 d of onset,the sensitivities were 84.2%,97.4% and 97.4%,respectively. SARS-CoV-2 IgM antibody showed a tendency to become positive on the 5th to 13th d after onset,and the tendency to turn negative was observed after the 18th d of onset. SARS-CoV-2 IgG antibody showed a tendency to turn positive on the 5th d and continued to be positive thereafter. Conclusions Serum SARS-CoV-2 IgM and IgG antibodies can be used as auxiliary diagnostic indicators of COVID-19,and the continuous monitoring of them can help with judging disease process.

Key words: Severe acute respiratory syndrome coronavirus 2, Antibody, Corona virus disease 2019