Dynamic changes and clinical significance of COVID-19 specific antibodies in rehabilitated patients / 中国热带医学

ABSTRACT

@#Abstract Objective To investigate the dynamic changes and clinical significance of specific antibodies in patients with coronavirus disease 2019 (COVID-19). Methods A retrospective study was conducted to collect 141 adult COVID-19 survivors who were followed up in the Eighth Hospital affiliated to Guangzhou Medical University from February 6, 2020, to March 24, 2021. The patients were divided into severe group (severe and critical) and non-severe group (light and ordinary) according to the diagnosis at discharge. The antibody changes of the two groups were compared and analyzed at 1 week, 2 weeks, 1 month, 3 months, 6 months and 1 year after discharge. Results After discharge from hospital, the positive rate of IgG in the severe group was 95.00% after 1 week and 100.00% in the following year, in the positive rate of IgG in the non-severe group was 59.50% after 1 week, 90.08% in 6 months and 76.03% in one year. The level of serum IgG in the severe group was significantly higher than that in non-severe group (Z=-2.441, P=0.015). One-year follow-up the serum IgG in the severe group was significantly higher than that in the non-severe group (Z=-3.410, P=0.001). The serum IgM level of the severe group after one year follow-up was lower than that of the six months follow-up, the difference was statistically significant (Z=-2.259, P=0.024). The serum IgG and IgM level of the non-severe group after one year follow-up was lower than that of the six months follow-up, the difference was statistically significant (Z=-7.37, P<0.01; Z=3.850, P<0.01). Conclusion The level of serum protective antibody in COVID-19 patients remained high within 6 months after discharge, and remained stable within 1 year after discharge. The antibody titers in the severe group were significantly higher than those in the non-severe group and lasted for at least one year. COVID-19 survivors receive 1 year of natural immune protection, and patients with critical conditions receive immunity for longer periods of time.