酶联免疫吸附法检测SARS-CoV-2血清抗体的临床价值

Clinical value of the serological test for SARS-CoV-2 specific antibody by using ELISA

目的探讨酶联免疫吸附法(ELISA)检测血清中严重急性呼吸综合征冠状病毒2(SARS-CoV-2)特异性抗体——免疫球蛋白(Ig)A、IgG在新型冠状病毒肺炎(COVID-19)诊断中的临床应用价值,以及探索IgA是否可以作为比IgG更灵敏的COVID-19诊断血清标志物。方法选取47例COVID-19确诊患者为研究对象,收集其年龄、性别、发病时间、入院时间、出院时间及采样时间等信息,采集血清样本124份,利用ELISA试剂盒和酶标仪检测患者血清中SARS-CoV-2特异性IgA和IgG抗体含量。结果患者中>20~40岁组人数最多占40.43%,>40~60岁组占36.17%,>60岁患者仅占10.64%。IgG检测阳性率较高,灵敏度最好,以IgG1(59.26%)和IgG3(44.44%)亚型为主;IgA的敏感性次于IgG,几乎所有IgA阳性标本都伴随IgG阳性。IgG和IgA阳性组患者的年龄高于抗体阴性组,15岁以下儿童和70岁以上老年患者均为IgA阴性。抗体阳性组与阴性组患者的住院天数及病程时长比较差异均无统计学意义(P>0.05)。IgG抗体水平随着发病时间延长而持续升高;而IgA抗体则在患者发病后的前3周逐渐升高,然后随着发病时间延长而逐渐下降。结论 ELISA法检测COVID-19患者血清中SARS-CoV-2特异性IgG抗体的敏感性较高,有良好的辅助诊断价值。

Objective To explore the clinical value of serological test for severe acute respiratory syndrome coronavirus 2(vSARS-CoV-2) specific antibody--IgA and IgG in the serum of corona virus disease 2019(COVID-19) patients by using ELISA,and confirm whether IgA could be a better serological diagnosis marker of COVID-19 than IgG.Methods A total of 124 serum samples from 47 COVID-19 patients were detected for SARS-CoV-2 specific IgA and IgG by ELISA.Two to 4 samples per patient were collected at different time points.The age,gender,onset time,admission time,discharge time and sampling time of patients were collected for data analysis.Results The patients aged>20-40 accounted for 40.43%followed by the patients aged>40-60(36.17%).The patients over>60 were the least,only 10.64%.SARS-CoV-2 IgG showed better sensitivity for the diagnosis of COVID-19 than SARS-CoV-2 IgA.The major IgG subtypes included IgGl(59.26%) and IgG3(44.44%).Of noted,almost all the IgA positive samples were also positive for IgG.The ages of IgA and IgG positive patients were significantly higher than those of antibody negative ones.Most patients were between 21 to 60 years old in the antibody positive group.IgA was negative in the samples of both children under 15 and old patients above 70 years old.There was no significant difference between the positive group and the negative group in the length of hospitalization and duration.The level of IgG antibody kept increasing with the time of onset,while IgA level displayed a rising trend in the first three weeks after onset,and then decreased gradually in the following two weeks.Conclusion SARSCoV-2 specific IgG test by using ELISA had a very good auxiliary diagnostic value for COVID-19.