2019å ç¶çæ¯ç康å¤èç¹å¼æ§IgGæä½æä»·çå½±åå ç´ åååè¶å¿./ 2019å ç¶çæ¯ç康å¤èç¹å¼æ§IgGæä½æä»·çå½±åå ç´ åååè¶å¿./ Influential factor and trend of specific IgG antibody titer in coronavirus disease 2019 convalescents.

OBJECTIVES: To explore the influential factors and titer trend of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific IgG antibody in convalescent patients with coronavirus disease 2019 (COVID-19), and to provide theoretical basis for the feasibility of clinical treatment of convalescent plasma. METHODS: Colloidal gold immunochromatography assay was used to detect the SARS-CoV-2 specific IgG antibody and its titer in 113 convalescent patients with COVID-19 who were followed up from February 19, 2020 to April 6, 2020. The basic characteristics and treatment factors of patients in the high titer group (antibody titer≥1ež‰160, n=22) and the low titer group (antibody titer 0.05). The male patients in the high titer group were more than those in the low titer group (P<0.05). The titer of SARS-CoV-2 specific IgG antibody in the high titer group decreased to less than 1ež‰160 28 d after discharge. CONCLUSIONS: Male COVID-19 patients might be more likely to produce high titer SARS-CoV-2 specific IgG antibodies than female. The peak level of SARS-CoV-2 specific IgG antibody in convalescent patients is maintained for a short period. Using plasma from convalescent COVID-19 patients for treatment should be within 28 d after discharge.