【摘要】 目的对蛋白酪氨酸磷酸酶-2自身抗体(IA-2A)放射配体检测法的影响因素进行分析。方法采用放射配体法检测186批IA-2A,对其检测结果进行回顾性分析和总结,并通过参加国际第4次糖尿病自身抗体检测标准化评估(DASP 2005)验证方法的灵敏度和特异度。结果该方法批内变异系数(CV)为3.1%~9.5%,批间CV为5.5%~11.7%;以信/噪比(S/N)≥50作为检测IA-2A的理想标准,186批次检测中合格161批(86.6%),失败25批(13.4%)。其中高温操作环境[(32.7±6.3)℃]检测失败率(占失败总批次的60%)显著高于低温操作环境[(11.8±5.7)℃,占失败总批次的16%],且高温操作环境S/N(55.1±6.9)明显低于低温操作环境(68.5±6.2,P<0.01)。在失败批次中,由三羟甲基氨基甲烷(Tris)缓冲盐溶液引起的占68%(17/25),其他原因有标记失败等。DASP 2005反馈结果显示,我室IA-2A检测灵敏度72%,特异度99%,受试者工作特征(ROC)曲线分析显示,曲线下面积0.825±0.048(0.730~0.919)。结论放射配体法检测IA-2A的影响因素,特别是Tris缓冲盐溶液应引起操作者重视并加以控制,以确保结果稳定可靠。更多还原

【Abstract】 Objective To study influencing factors of protein tyrosine phosphatase-2 autoantibody(IA-2A) measurement by radioligand assay.Methods The influencing factors of IA-2A determined by radioligand assay in 186 batches was analyzed.The sensitivity and specificity of the assay were evaluated in the fourth Diabetes Autoantibody Standardization Program(DASP 2005) sponsored by the Immunology of Diabetes Society(IDS).Results The intra-assay coefficient of variation(CV) was 3.1%-9.5% and inter-assay CV was 5.5%-11.7%.A ratio of signal to noise(S/N) with 50 or more was defined as a valid measurement.Of the 186 batches,161 batches(86.6%) met with the standard and the other 25 batches(13.4%) were not qualified.When the results were analyzed according to the work environment,the failure rate in hot environment [(32.7±6.3)℃] was significantly higher than that in cold environment [(11.8±5.7)℃,60% vs 16%].In addition,the value of S/N in hot environment was significantly lower than that in cold environment(55.1±6.9 vs 68.5±6.2,P<0.01).Among the failed batches,68%(17/25) was caused by Tris buffer,other causes included failed labeling etc.The results from DASP 2005 showed that the sensitivity and specificity for IA-2A was 72% and 99% respectively.Receiver operating characteristic(ROC) analysis showed that the area under curve was 0.825±0.048(0.730-0.919). Conclusions Tris buffer and other influencing factors of radioligand assay in determining IA-2A should be controlled strictly to ensure a reliable and repeatable result.更多还原