Department of Medicine I, Gutenberg University Medical Center, Mainz, Germany.
Clin Exp Immunol. 2010 Dec;162(3):438-46. doi: 10.1111/j.1365-2249.2010.04266.x.
Thyroid-stimulating immunoglobulins (TSI) are a functional biomarker of Graves' disease (GD). To develop a novel TSI bioassay, a cell line (MC4-CHO-Luc) was bio-engineered to constitutively express a chimeric TSH receptor (TSHR) and constructed with a cyclic adenosine monophosphate (cAMP)-dependent luciferase reporter gene that enables TSI quantification. Data presented as percentage of specimen-to-reference ratio (SRR%) were obtained from 271 patients with various autoimmune and thyroid diseases and 180 controls. Sensitivity of 96% and specificity of 99% for untreated GD were attained by receiver operating characteristic analysis, area under the curve 0·989, 95% confidence interval 0·969-0·999, P = 0·0001. Precision testing of manufactured reagents of high, medium, low and negative SRR% gave a percentage of coefficient-of-variation of 11·5%, 12·8%, 14·5% and 15·7%, respectively. There was no observed interference by haemoglobin, lipids and bilirubin and no non-specific stimulation by various hormones at and above physiological concentrations. TSI levels from GD patients without (SRR% 406 ± 134, mean ± standard deviation) or under anti-thyroid treatment (173 ± 147) were higher (P < 0·0001) compared with TSI levels of patients with Hashimoto's thyroiditis (51 ± 37), autoimmune diseases without GD (24 ± 10), thyroid nodules (30 ± 26) and controls (35 ± 18). The bioassay showed greater sensitivity when compared with anti-TSHR binding assays. In conclusion, the TSI-Mc4 bioassay measures the functional biomarker accurately in GD with a standardized protocol and could improve substantially the diagnosis of autoimmune diseases involving TSHR autoantibodies.
甲状腺刺激免疫球蛋白（TSI）是格雷夫斯病（GD）的功能性生物标志物。为了开发新的 TSI 生物测定法，构建了一种稳定表达嵌合 TSH 受体（TSHR）的细胞系（MC4-CHO-Luc），并构建了一个环磷酸腺苷（cAMP）依赖性荧光素酶报告基因，可用于 TSI 定量。从 271 名患有各种自身免疫性和甲状腺疾病的患者和 180 名对照中获得了以标本与参考比值（SRR%）表示的数据。通过接受者操作特征分析，未治疗 GD 的敏感性为 96%，特异性为 99%，曲线下面积为 0.989，95%置信区间为 0.969-0.999，P=0.0001。对高、中、低和负 SRR%的制造试剂进行精密测试，得出的变异系数百分比分别为 11.5%、12.8%、14.5%和 15.7%。血红蛋白、脂质和胆红素没有观察到干扰，各种激素在生理浓度及以上没有非特异性刺激。未经（SRR%406±134，平均值±标准差）或经抗甲状腺治疗（173±147）的 GD 患者的 TSI 水平高于桥本甲状腺炎（51±37）、无 GD 的自身免疫性疾病（24±10）、甲状腺结节（30±26）和对照组（35±18）的 TSI 水平（P<0.0001）。与抗 TSHR 结合测定相比，该生物测定法显示出更高的敏感性。总之，该 TSI-Mc4 生物测定法在使用标准化方案时可以准确测量 GD 的功能性生物标志物，并且可以大大改善涉及 TSHR 自身抗体的自身免疫性疾病的诊断。
