TgAb对ECLIA和RIA测定Tg影响的对比研究

Research on Comparison of Thyroglobulin Autoantibody Interference in Measurement of Thyroglobulin Between Electrochemiluminescent Assay and Radioimmunoassay

采用电化学发光免疫分析(ECLIA)法和放射免疫分析(RIA)法同时测定甲状腺球蛋白(Tg)、自身甲状腺球蛋白抗体(TgAb),用回收实验研究TgAb对Tg测定的影响。选取84例甲状腺疾病患者血样,分别测定Tg、TgAb,将结果进行相关性分析。回收实验第一组分别加入50、100和200ng/ml的标准Tg;第二组对倍稀释5次,加入100ng/ml标准Tg;第三组为TgAb浓度梯度组,加入100ng/ml标准Tg。结果表明,两种方法Tg值均大于10ng/ml的31例标本,相关系数为0.676(P=0.000)。TgAb值的相关系数为0.677(P=0.000)。TgAb浓度增加,ECLIA法Tg值逐渐降低,RIA法Tg值逐渐升高。血清稀释后,ECLIA法Tg值和回收率逐渐升高,RIA法Tg值和回收率逐渐下降。不同标准Tg对Tg回收率无明显影响。两种方法测定Tg和TgAb有较好的相关性。ECLIA法比RIA法测定范围更宽,灵敏度更高。TgAb使ECLIA法可能低估Tg值,使RIA法可能高估Tg值。TgAb干扰Tg测定没有阈值存在。回收实验不能完全校正TgAb干扰导致的偏差。

This paper is aimed to evaluatethe thyroglobulin autoantibody（TgAb） interference in measurement of thyroglobulin（Tg） between electrochemiluminescent assay（ECLIA） and radioimmunoassay（RIA）.Tg and TgAb of 84 sera,including 22 Graves＇ hyperthyroidism（GD）,24 Hashimoto thyroiditis（HT） and 38 differentiated thyroid carcinomas（DTC）,were measured by RIA and ECLIA,respectively.Recovery tests were carried out in 3 groups.The sera samples of the first group were added 3 different amount of Tg calibrator;the sera samples of the second group were diluted 5 times,then 100ng/ml Tg calibrator was added;the sera samples of the third group were divided into different subgroups depending on TgAb concentration with adding 100ng/ml Tg calibrator,Tg and TgAb were measured in each dilution by ECLIA and RIA.Recovery rate was calculated.The Tg and TgAb values measured by ECLIA were correlated with that measured by RIA（r=0.676,P=0.000;r=0.677,P=0.000,respectively）.When TgAb concentration increased,the Tg values decreased by ECLIA and increased by RIA.The TgAb values were decreased when sera were diluted,and the Tg values also reduced by RIA and increased by ECLIA.The added different amount of Tg calibrator had not significant influence on Tg recovery rates.When TgAb concentration increased,recovery rates of Tg were decreased by ECLIA and increased by RIA.When sera were diluted,the recovery rates of Tg were increased by ECLIA while decreased by RIA.RIA and ECLIA have good correlation with Tg measurement in 10-400ng/ml.ECLIA has wider measuring range and higher sensitivity than RIA.RIA and ECLIA have good correlation with TgAb measurement.When TgAb is positive,Tg values are underestimated by ECLIA and overestimated by RIA.When sera are diluted,Tg value and the recovery rate are increasing by ECLIA and decreased by RIA.Recovery test can not efficiently rectify Tg value when TgAb is positive.