酶联免疫吸附试验与中和抗体试验检测麻疹抗体比较研究

目的探讨酶联免疫吸附试验(ELISA)和中和抗体试验(NT)在麻疹抗体检测中的应用价值。方法以NT为"金标准",同时用德国Virion/Serion的定量ELISA试剂盒检测364份麻疹抗体滴度,将两种方法测定的结果进行比较。结果 NT的阳性率为57.69%,几何平均滴度(GMT)为1∶5.48,ELISA的阳性率为42.86%,平均抗体活性值为48.57IU/L。定性结果发现,ELISA特异度为99.35%,其敏感度即阳性符合率为73.81%,且阳性符合率随着滴度增加呈现增高的趋势(z=-5.99,P<0.001)。Fisher精确概率法发现,滴度1∶2组、滴度1∶4组与其他各组阳性符合率差异均有统计学意义(P<0.05),滴度1∶8组与滴度≥1∶64组阳性符合率差异有统计学意义(P<0.05),其余各组间阳性符合率差异均无统计学意义(P>0.05)。定量结果发现,ELISA抗体活性值与NT滴度呈明显正相关,相关系数r=0.884,P<0.001。结论德国Virion/Serion的定量ELISA试剂盒在检测低滴度麻疹抗体时易出现假阴性,检测高滴度麻疹抗体时,两种方法敏感性接近;滴度临界值为1∶8～1∶16。该试剂可推荐用于健康人群麻疹抗体水平监测。

Comparison of ELISA and neutralization test in the detection of measles antibody

Objective To explore the diagnostic value of ELISA and neutralization test（Nt） in the detection of measles antibody.Methods A total of 364 serum samples were tested for measles antibody by ELISA and Nt.Nt is a traditional method and still considered as gold standard for the detection of measles antibody.The performance of quantitative ELISA kit（Virion/Serion,German） was compared to Nt.Results The positive rate and activity of measles antibody were 42.86% and 48.57 mIU/ml by ELISA,and were 57.69% and 1∶5.48（GMT） by Nt,respectively.The specificity of ELISA was 99.35%.The positive coincidence rate of measles antibody was 73.81% between the two methods and increased with antibody titer（z=-5.99,P0.001）.There was a correlation between the concentrations of measles antibody quantified by Nt（titer） and ELISA（IU）（r=0.884,P0.001）.Conclusion Nt is more sensitive than ELISA in the detection of serum with measles antibody titer lower than 1∶8.The ELISA kit is applicable for epidemiological survey among healthy population.