Department of Endocrinology and Metabolism, Peking University People's Hospital, N0.11, Xi Zhi Men Nan Da Jie, Xicheng District, Beijing, 100044, China.
Department of Endocrinology and Metabolism, the Second People's Hospital, Guiyang, 550000, China.
BMC Endocr Disord. 2022 Aug 31;22(1):218. doi: 10.1186/s12902-022-01114-3.
The rapid and accurate detection of thyroid-stimulating hormone (TSH) receptor antibodies has always been an urgent need for the clinical diagnosis and management of Graves' disease (GD). We aimed to evaluate the use of an automated thyroid-stimulating immunoglobulin (TSI) bridge immunoassay in the diagnosis of GD and to analyze the relationship between TSI and the degree of hyperthyroidism.
A total of 227 new-onset GD patients, 29 Hashimoto thyroiditis, 43 non-autoimmune thyroid diseases and 37 euthyroid controls were consecutively recruited. All participants accepted the measurement of their serum thyroid function and thyroid-associated antibodies, including TSI being measured by an Immulite 2000 bridge immunoassay and TSH receptor autoantibodies (TRAb) being measured by a third-generation Roche electrochemiluminescence immunoassay. The quantitative consistency between the TSI and TRAb detection methods was analyzed by using Passing-Bablok regression and Bland-Altman plots. The diagnostic performance for GD was assessed by receiver operating characteristic (ROC) curve analysis.
Among 227 GD patients (174 females and 53 males, with a mean age of 39 years), the quantitative TSI was positively correlated with TRAb (r = 0.8099). According to the cut-off values proposed by the manufacturers (TSI: 0.55 IU/L, TRAb: 1.75 IU/L), the positive rates of TSI and TRAb in new-onset GD patients were 96.92% and 95.15%, respectively. Both TSI and TRAb levels positively correlated with FT levels (TSI: r = 0.243, TRAb: r = 0.317; all P < 0.001) and FT levels (TSI: r = 0.288, TRAb: r = 0.360; all P < 0.001) in new-onset GD patients. The ROC analysis showed that the optimal TSI cut-off value was 0.577 IU/L for GD diagnosis in this Chinese population, with a sensitivity of 96.92% and a specificity of 97.25%, respectively. The optimal TRAb cut-off value of was 1.38 IU/L, with a sensitivity of 96.92% and a specificity of 99.08%. There were no significant differences between the cut-off values obtained through the ROC analysis and those provided by the manufacturer for both TSI and TRAb when calculating their sensitivity and specificity in diagnosing GD. Among the 8 newly diagnosed GD cases with discordant qualitative antibody results, TSI was more likely than TRAb to match the clinical diagnosis of GD (6 TSI-positive vs. 2 TRAb-positive patients).
The automated TSI bridge immunoassay was positively correlated with thyroxine levels in new-onset GD patients and was more likely to be consistent with the clinical diagnosis of GD than with that of TRAb. The positive Immulite 2000 TSI cut-off value of 0.577 IU/L for GD diagnosis in the Chinese population were close to the value recommended by the manufacturer.
快速准确地检测促甲状腺激素（TSH）受体抗体一直是 Graves 病（GD）临床诊断和管理的迫切需要。我们旨在评估自动化甲状腺刺激免疫球蛋白（TSI）桥联免疫测定在 GD 诊断中的应用，并分析 TSI 与甲状腺功能亢进程度的关系。
连续招募了 227 例新诊断的 GD 患者、29 例桥本甲状腺炎、43 例非自身免疫性甲状腺疾病和 37 例甲状腺功能正常对照者。所有参与者均接受了血清甲状腺功能和甲状腺相关抗体的检测，包括使用 Immulite 2000 桥联免疫测定法检测 TSI 和第三代罗氏电化学发光免疫测定法检测 TSH 受体自身抗体（TRAb）。采用 Passing-Bablok 回归和 Bland-Altman 图分析 TSI 和 TRAb 检测方法的定量一致性。通过受试者工作特征（ROC）曲线分析评估 GD 的诊断性能。
在 227 例 GD 患者（174 名女性和 53 名男性，平均年龄 39 岁）中，定量 TSI 与 TRAb 呈正相关（r=0.8099）。根据制造商提出的临界值（TSI：0.55 IU/L，TRAb：1.75 IU/L），新诊断 GD 患者 TSI 和 TRAb 的阳性率分别为 96.92%和 95.15%。TSI 和 TRAb 水平均与 FT 水平呈正相关（TSI：r=0.243，TRAb：r=0.317；均 P<0.001）和 FT 水平（TSI：r=0.288，TRAb：r=0.360；均 P<0.001）。ROC 分析显示，在中国人群中，TSI 的最佳临界值为 0.577 IU/L，用于诊断 GD，其灵敏度为 96.92%，特异性为 97.25%。最佳 TRAb 临界值为 1.38 IU/L，灵敏度为 96.92%，特异性为 99.08%。在计算 TSI 和 TRAb 用于诊断 GD 的灵敏度和特异性时，ROC 分析得出的临界值与制造商提供的临界值之间没有显著差异。在 8 例新诊断的 GD 病例中，抗体结果定性不一致，TSI 比 TRAb 更符合 GD 的临床诊断（6 例 TSI 阳性 vs. 2 例 TRAb 阳性患者）。
自动化 TSI 桥联免疫测定与新诊断 GD 患者的甲状腺素水平呈正相关，与 GD 的临床诊断比 TRAb 更一致。在中国人群中，用于 GD 诊断的 Immulite 2000 TSI 阳性临界值为 0.577 IU/L，接近制造商推荐的临界值。
