目的评价甲状腺组织完全去除后当血清甲状腺球蛋白(TG)阴性时,抗甲状腺球蛋白抗体(TGAb)对分化型甲状腺癌(DTC)的诊断价值,确定TGAb的诊断临界点。方法选择169例术后病理诊断为DTC,残留甲状腺组织已完全去除,TG阴性、TGAb阳性的患者,将其分为:复发/转移组(A组)59例和无复发/转移组(B组)110例。以电化学发光法测定血清TG、TGAb水平,根据其TGAb值进行受试者丁作特征(ROC)曲线及不同阈值的阳性分层似然比分析。结果A组的TGAb值(1368±1343)IU/ml明显高于B组(154±539)IU/ml(P<0.01)。ROC曲线下面积为0.945(P<0.01),说明TGAb对这类患者具有较高的诊断价值。诊断临界点为204 IU/ml,其敏感度、特异度分别为91.50%、89.10%,与金标准相比较,诊断效率差异无统计学意义(P=0.143),吻合度较强(κ=0.785,P<0.01)。当验前概率固定且排除其它混杂因素作用,TGAb>1000 IU/ml发生复发/转移的可能性为204 IU/ml≤TGAb≤1000 IU/ml的1.12倍、100 IU/ml≤TGAb<204 IU/ml的4.03倍、10 IU/ml≤TGAb<100 IU/ml的24.79倍。结论TGAb可作为监测术后残留甲状腺组织已完全去除且TG阴性TGAb阳性DTC患者发生复发/转移的指标,其诊断临界点为204 IU/ml。TGAb值越高,发生复发/转移的可能性越大。 Objective To evaluate the diagnostic value of anti-thyroglobulin antibody (TGAb) for differentiated thyroid cancer (DTC) when serum thyroglobulin (TG) is negative after thyroid tissue is completely removed and determine the diagnostic threshold of TGAb. Methods Sixty-nine patients with DTC who were diagnosed as postoperative pathology, residual thyroid tissue was completely removed, and TG negative and TGAb positive were divided into 59 cases of recurrence / metastasis (group A) and no recurrence / metastasis (group B) ) 110 cases. The levels of TG and TGAb in serum were determined by electrochemiluminescence. The ROC curve and the positive stratified likelihood ratio analysis of different thresholds were performed according to their TGAb values. Results The TGAb value (1368 ± 1343) IU / ml in group A was significantly higher than that in group B (154 ± 539) IU / ml (P <0.01). The area under the ROC curve was 0.945 (P <0.01), indicating that TGAb has a high diagnostic value for these patients. The diagnostic accuracy was 204 IU / ml, the sensitivity and specificity were 91.50% and 89.10%, respectively. There was no significant difference in diagnostic efficiency between the two groups (P = 0.143) (χ = 0.785 , P <0.01). The probability of recurrence / metastasis of TGAb> 1000 IU / ml is 1.12 times as high as 204 IU / ml≤TGAb≤1000 IU / ml when the pretest probability is fixed and other confounding factors are excluded. 100 IU / ml≤TGAb <204 IU 4.03 times / ml, 24.79 times 10 IU / ml