Objective: To study the application of measles specific IgM and IgG antibody detection in classification of primary vaccination failure (PVF) and secondary vaccination failure (SVF). Methods: Measles surveillance information system was used to collect measles confirmed cases in Tianjin, 2013-2015, and their blood specimens were collected, totally 284 cases were enrolled. Measles IgM and IgG were detected with enzyme-linked immunosorbent assay (ELISA), and the relative avidity index (RAI) was used to express the result of measles avidity. Measles IgM, IgG and IgM/IgG was analyzed with receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC) as evaluation indicators. In addition, compared with a measles outbreak (26 cases) of a middle school in Tianjin in 2016, for making further verification on the diagnostic value of vaccination failure with IgM, IgG and IgM/IgG. Results: The age of cases ranged was 0-58 years old, the interval median (P(25), P(75)) of serum collection after rash onset was 2 (1, 4) days. The positive rate of measles IgM and IgG in acute phase specimens were 76.06% (216 cases) and 88.38% (251 cases). According to the ROC curve analysis, the area under the ROC curve (AUC) of IgM, IgG and IgM/IgG were 0.753, 0.891 and 0.952, indicating that IgM/IgG was the best index to distinguish PVF and SVF. The best cut off value for IgM/IgG was 0.06, the sensibility and specificity were 88.75% and 86.63%. When IgM/IgG >1, 96.30% cases were low-avidity (RAI <40%), only 1 case was equivocal response (RAI: 40%-60%). 97.14% cases were high-avidity (RAI >60%) when IgM/IgG <0.01, only 3 cases were equivocal response (RAI 40%-60%). The threshold of IgM/IgG was used to verify the measles outbreak of a middle school in Tianjin, 2016. In the acute phase specimens, 100% (26 cases) of IgM/IgG were <0.06, 84.62% (22 cases) of IgM/IgG were <0.01. Conclusion: The detection of measles IgM and IgG with ELISA, and IgM/IgG is a valuable diagnostic tool to distinguish PVF and SVF.
目的： 探讨麻疹IgM和IgG抗体在判定原发性免疫失败（PVF）和继发性免疫失败（SVF）的应用。 方法： 以中国疾病预防控制信息系统中2013—2015年天津市上报的麻疹确诊病例为研究对象，获取其血清标本，共284例。采用ELISA检测麻疹IgM和IgG抗体，通过相对亲和力指数（RAI）判定亲和力检测结果；采用受试者工作特征（ROC）曲线分析麻疹IgM、IgG和IgM/IgG评价方法，利用曲线下面积（AUC）比较不同指标的判定价值。同时，对2016年天津市一起中学麻疹暴发（26例）进行分析，验证麻疹IgM、IgG和IgM/IgG评价方法在判定疫苗免疫失败的诊断价值。 结果： 研究对象年龄为0~58岁，采样间隔M（P(25)，P(75)）为2（1，4）d。麻疹IgM和IgG抗体阳性率分别为76.06%（216例）和88.38%（251例）。ROC曲线分析显示，麻疹IgM、IgG和IgM/IgG评价方法的AUC分别为0.753、0.891和0.952，采用麻疹IgM/IgG值判定PVF和SVF效果较好；麻疹IgM/IgG评价方法的最佳临界值为0.06，灵敏度88.75%，特异度86.63%。当麻疹IgM/IgG值>1时，96.30%（26例）的病例检测为低亲和力（RAI<40%），只有1例为可疑（RAI：40%~60%）；当麻疹IgM/IgG值<0.01时，97.14%（102例）的病例为高亲和力（RAI>60%），只有3例为可疑（RAI：40%~60%）。以麻疹IgM/IgG值的临界值对2016年天津市中学麻疹暴发进行验证，急性期标本100%（26例）麻疹IgM/IgG值<0.06，84.62%（22例）麻疹IgM/IgG值<0.01。 结论： 利用ELISA方法检测麻疹IgM和IgG抗体后，采用麻疹IgM/IgG值判定PVF和SVF具有良好的诊断价值。.
Keywords: Immunoglobulin G; Immunoglobulin M; Measles; Primary vaccination failure; Secondary vaccination failure.