新型冠状病毒感染者6个月后抗体滴度分析

Analysis of antibody titers in patients with COVID-19 6months after infection

目的 对湖北省大悟县确诊和疑似新型冠状病毒肺炎(Coronavirus Disease 2019,COVID-19)康复者出院6个月后抗严重急性呼吸综合征冠状病毒2(severe acute respiratory syndromecoronavirus 2,SARS-CoV-2)抗体进行分析。方法 收集COVID-19康复者出院6个月后血清样本166例,采用蚀斑减少中和试验(plaque reduction neutralization test,PRNT)检测血清抗SARS-CoV-2中和抗体,计算中和抗体滴度(EC_(50));ELISA法检测抗SARS-CoV-2特异性IgG抗体滴度,并采用Pearson进行相关性分析。结果 166例样本中和抗体及特异性IgG抗体总阳性率分别为68.7%和77.7%,其中有典型症状确诊人群分别为82.2%和90.1%,无症状确诊人群分别为66.7%和88.9%,疑似人群分别为44.6%和53.6%。中和抗体与特异性IgG抗体滴度间的相关性为93.0%,两者检测方法高度相关。结论 医院确诊和疑似COVID-19患者出院6个月后的抗SARS-CoV-2抗体仍持续存在,且抗体滴度与抗SARS-CoV-2特异性IgG抗体滴度显著相关。

Objective To analyze the antibody against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)of recovered patients with confirmed or suspected Coronavirus Disease 2019(COVID-19)in Dawu County,Hubei Province,China 6 months after discharge from hospital. Methods A total of 166 serum samples were collected from the recovered patients with COVID-19 6 months after discharge from hospital and determined for neutralizing antibody by plaque reduction neutralization test(PRNT),and the neutralizing antibody titer(EC_(50))was calculated. The specific IgG antibody against SARS-CoV-2 was determined by ELISA,of which the relationship to the neutralizing antibody titer was analyzed by Pearson method. Results The positive rates of neutralizing antibody and specific IgG in the 166 samples were 68. 7%and 77. 7%,while those in samples from patients with typical symptoms were 82. 2%,and 90. 1%,those from confirmed patients without symptoms were 66. 7% and 88. 9%,and those from suspected patients were 44. 6% and 53. 6%,respectively. The Pearson relationship between neutralizing antibody titer and IgG titer was 93. 0%. Conclusion The antibody against SARS-CoV-2 still exists in patients with confirmed or suspected COVID-19 6 months after discharge from hospital,and the titer of neutralizing antibody is significantly related to that of specific IgG against SARS-CoV-2.