儿童及孕产妇HIV抗体初筛阳性结果与确证试验结果分析

Analysis of the Positive Results of HIV Antibody Screening Test and Confirmatory Test in Children and Pregnant Women

目的 分析比较婴幼儿、儿童及孕产妇等特殊群体艾滋病病毒(HIV)抗体初筛试验阳性与确证试验阳性符合率,探讨儿童及孕产妇,不同检测方法初筛假阳性的原因。方法 65例HIV抗体初筛阳性样本用免疫印迹试验(WB)进行确证试验,将初筛阳性病例根据年龄段、酶联免疫吸附试验、化学发光微粒子免疫检测试验(CMIA)的样本信号值/临界值比值(S/CO)与WB确证结果进行比较分析。结果 65份初筛阳性样本的总体确证阳性率为83.08%(54/65),儿童组确证阳性率为53.85%,显著低于新生儿组100.00%、婴幼儿组100.00%、孕产妇组78.95%和非孕产妇组93.33%,其差异有统计学意义(P=0.009 2)。孕产妇组与非孕产妇组确证阳性率比较差异无统计学意义(P=0.607 4)。ELISA与CMIA确证阳性率比较,差异无统计学意义(P=0.346 5)。酶联免疫吸附试验在S/CO>10的区段,确证阳性率最高达97.62%。化学发光微粒子免疫检测试验在S/CO值>50的区段,确证阳性率最高达95.12%。ELISA、CMIA和S/CO联合受试者工作特征曲线(ROC),判定HIV抗体初筛阳性样本为确证阳性的曲线下面积(area under curve,AUC)为0.979,敏感度为87.80%,特异度为100.00%,Youden指数为0.878。结论 儿童及孕产妇HIV抗体初筛试验假阳性率较高,临床医生应根据实验结果并结合流行病学史、不同检测方法学与检测值高低等综合资料作出HIV感染判断。酶联免疫吸附试验、化学发光微粒子免疫检测试验S/CO值越高,确证阳性率越高。

Objective To analyze the consistency between the positive results of the human immunodeficiency virus(HIV) screening test and the confirmatory test results for infants,children and pregnant women,and to explore the causes of false positives in screening test in children,pregnant women with different detection methods.Methods A total of 65 patients with positive HIV antibody results in screening test were confirmed with Western blot(WB).The results of WB were compared with the positive screening test according to the age distribution,detection methods and sample signal to cut-off(S/CO) rate of enzyme-linked immunosorbent assay(ELISA) and chemiluminescence microparticle immunoassay(CMIA).Results The confirmed positive rate for total samples was 83.08%(54/65).The confirmed positive rate for the children was 53.85%,which was significantly lower than that of the neonates(100.00%),infants(100.00%),pregnant women cases(78.95%) and non-pregnant women(93.33%)(P=0.009 2).There was no significant difference between the pregnant women and non-pregnant women(P=0.607 4).There was no significant difference of confirmed positive rate between ELISA and CMIA(P=0.346 5).In the segment with S/CO value 10,the confirmed positive rate of ELISA reached 97.62%.The confirmed positive rate of CMIA was up to 95.12% in the range of S/CO value50.Using receiver operating characteristic(ROC) curve of S/CO valve combined with ELISA and CMIA,to determine the positive screening test were positive confirmatory test,the area under curve(AUC) of confirmed positive HIV antibody samples in screening test was 0.979,the sensitivity was 87.80%,the specificity was 100.00%,and the Youden index was 0.878.Conclusion The false positive rate was high in HIV antibody screening test in children and pregnant women,and the diagnosis of HIV infection should be considered based on the experimental results,combined with comprehensive data such as epidemiological history,different testing methods,and high or low test values.The higher the S/CO value in ELISA and CMIA test,the higher confirmed positive rate.