Kinetics of SARS-CoV-2 specific IgM and IgG responses in COVID-19 patients

• Published in: Emerging microbes & infections 2020-01, Vol.9 (1), p.940-948
• Main Authors: Sun, Baoqing, Feng, Ying, Mo, Xiaoneng, Zheng, Peiyan, Wang, Qian, Li, Pingchao, Peng, Ping, Liu, Xiaoqing, Chen, Zhilong, Huang, Huimin, Zhang, Fan, Luo, Wenting, Niu, Xuefeng, Hu, Peiyu, Wang, Longyu, Peng, Hui, Huang, Zhifeng, Feng, Liqiang, Li, Feng, Zhang, Fuchun, Li, Fang, Zhong, Nanshan, Chen, Ling
• Format: Article
• Language: English
• Subjects: Aged; Antibodies, Viral - blood; Antibodies, Viral - immunology; Betacoronavirus - immunology; C-reactive protein; C-Reactive Protein - analysis; C-Reactive Protein - immunology; Clinical Laboratory Techniques; Coronavirus Infections - blood; Coronavirus Infections - diagnosis; Coronavirus Infections - immunology; Coronavirus Nucleocapsid Proteins; Coronaviruses; COVID-19; COVID-19 Testing; Critical Care - statistics & numerical data; Female; Humans; IgG; IgM; Immunoglobulin G - blood; Immunoglobulin G - immunology; Immunoglobulin M - blood; Immunoglobulin M - immunology; Kinetics; Male; Middle Aged; Nucleocapsid Proteins - blood; Nucleocapsid Proteins - immunology; Pandemics; Phosphoproteins; Pneumonia, Viral - blood; Pneumonia, Viral - diagnosis; Pneumonia, Viral - immunology; Proteins; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Spike Glycoprotein, Coronavirus - blood; Spike Glycoprotein, Coronavirus - immunology
• ISSN: 2222-1751; 2222-1751
• DOI: 10.1080/22221751.2020.1762515

The emerging COVID-19 caused by SARS-CoV-2 infection poses severe challenges to global public health. Serum antibody testing is becoming one of the critical methods for the diagnosis of COVID-19 patients. We investigated IgM and IgG responses against SARS-CoV-2 nucleocapsid (N) and spike (S) protein after symptom onset in the intensive care unit (ICU) and non-ICU patients. 130 blood samples from 38 COVID-19 patients were collected. The levels of IgM and IgG specific to N and S protein were detected by ELISA. A series of blood samples were collected along the disease course from the same patient, including 11 ICU patients and 27 non-ICU patients for longitudinal analysis. N and S specific IgM and IgG (N-IgM, N-IgG, S-IgM, S-IgG) in non-ICU patients increased after symptom onset. N-IgM and S-IgM in some non-ICU patients reached a peak in the second week, while N-IgG and S-IgG continued to increase in the third week. The combined detection of N and S specific IgM and IgG could identify up to 75% of SARS-CoV-2 infected patients in the first week. S-IgG was significantly higher in non-ICU patients than in ICU patients in the third week. In contrast, N-IgG was significantly higher in ICU patients than in non-ICU patients. The increase of S-IgG positively correlated with the decrease of C-reactive protein (CRP) in non-ICU patients. N and S specific IgM and IgG increased gradually after symptom onset and can be used for detection of SARS-CoV-2 infection. Analysis of the dynamics of S-IgG may help to predict prognosis.