第3代TRAb测定(Elecsys)对甲状腺毒血症的鉴别诊断价值

目的： 探讨第3代促甲状腺素受体抗体（TRAb）检测方法——电化学发光法（Elecsys）对甲状腺毒血症病因鉴别的诊断价值。方法： 回顾性选取2016年1月至2018年5月复旦大学附属华山医院收治的未经治疗的甲状腺毒血症患者154例，测定其甲状腺功能、TRAb、甲状腺摄碘率和甲状腺上动脉收缩期峰值流速（peak systolic velocity of superior thyroid artery，STA-PSV）。采用ROC曲线比较第3代TRAb及STA-PSV对Graves病（Graves''disease，GD）和破坏性甲状腺炎（destructive thyroiditis，DT）的鉴别诊断价值。结果： 154例甲状腺毒血症患者中，女性111例（72.0%），平均年龄38.42岁，GD 117例（76.0%）。TRAb的AUC为0.984（95% CI 0.967~1.000），优于STA-PSV （AUC 0.903，95% CI 0.839~0.967）。TRAb的最佳切割点为1.7 U/L，区分GD和DT的灵敏度和特异度为94.8%和94.3%。TRAb切割点为3.6 U/L时，其鉴别GD/DT的特异度和阳性预测值均为100%。结论： 第3代TRAb检测（Elecsys）对甲状腺毒症的病因鉴别具有较高的灵敏度和特异度。

Clinical value of the third generation assay for TSH receptor antibody (Elecsys TRAb) for the differential diagnosis of thyrotoxicosis

Objective: To explore the applicability of 3^rd generation thyroid stimulating hormone receptor antibody (TRAb) assay (Elecsys) in clinical differentiation of thyrotoxicosis. Methods: 154 subjects with untreated thyrotoxicosis, who were admitted to Huashan Hospital between January 2016 and May 2018 were retrospectively selected. Thyroid function, TRAb, radioactive iodine uptake (RAIU), and mean peak systolic velocity of superior thyroid artery (STA-PSV) were detected. Receiver operating characteristic (ROC) curves were plotted to compare the value of the third generation TRAb and STA-PSV in the differential diagnosis of Graves''disease (GD) and destructive thyroiditis (DT). Results: Of the 154 subjects with untreated thyrotoxicosis enrolled, 111 (72.0%) were female, their mean age were 38.42 years. Totally, 117 (76.0%) were diagnosed as GD. The area under the ROC curve for TRAb in the differential diagnosis of thyrotoxicosis was 0.984 (95%CI 0.967-1.000), superior to that of STA-PSV (AUC 0.903, 95%CI 0.839-0.967). The best cutoff point of TRAb was 1.7 U/L, the sensitivity and specificity in distinguishing GD from DT were 94.8% and 94.3%, respectively. If TRAb cutoff point was set 3.6 U/L, its specificity and postive predictive value in GD differentiation reached 100%. There are 5 TRAb negative (<1.7 U/L) GD cases, all of whom have significantly elevated STA-PSV. Conclusions: The 3^rd generation TRAb assay (Elecsys) is sensitive and specific in the differential diagnosis of thyrotoxicosis.