Ordóñez-Llanos J, Rodríguez-Espinosa J, Gómez-Gerique J A
J Endocrinol Invest. 1984 Apr;7(2):123-7. doi: 10.1007/BF03348401.
Thyroid hormone levels were studied in a euthyroid patient with hepatocellular carcinoma. The thyroid gland was normal at autopsy and both antithyroglobulin and antimicrosomal antibodies were undetectable in serum. Serum triiodothyronine (T3) values as measured by different RIA procedures, showed striking discrepancies suggesting the presence of an endogenous T3 binding antibody. The preincubation of the patient's serum with 125I-T3, followed by a precipitation with polyethyleneglycol showed a 74.8% of binding, confirming the presence of an endogenous factor interfering with T3 assays. Agarose electrophoresis of the patient's serum showed that 125I-T3 migrated mainly with the gammaglobulin fraction (60%). When immunoprecipitation tests with different antihuman antiimmunoglobulins were carried out, a positive binding for immunoglobulin G (11.9%), Fab (8.5%) and lambda chain (9.3%) was noted. Scatchard plot analysis showed a binding affinity of 0.77 X 10(9) liter/mol and a binding capacity of 1.02 nmol/liter. These data suggest that the abnormal serum T3 binding was caused by the presence of a T3 antibody which was shown to be an immunoglobulin G specific only for the lambda chain.
对一名患有肝细胞癌的甲状腺功能正常的患者进行了甲状腺激素水平研究。尸检时甲状腺正常，血清中抗甲状腺球蛋白和抗微粒体抗体均未检测到。通过不同放射免疫分析程序测量的血清三碘甲状腺原氨酸（T3）值显示出显著差异，提示存在内源性T3结合抗体。患者血清与125I-T3预孵育，随后用聚乙二醇沉淀，结果显示结合率为74.8%，证实存在干扰T3检测的内源性因子。患者血清的琼脂糖电泳显示125I-T3主要与γ球蛋白部分一起迁移（60%）。当用不同的抗人抗免疫球蛋白进行免疫沉淀试验时，发现免疫球蛋白G（11.9%）、Fab（8.5%）和λ链（9.3%）呈阳性结合。Scatchard图分析显示结合亲和力为0.77×10（9）升/摩尔，结合容量为1.02纳摩尔/升。这些数据表明，异常的血清T3结合是由一种T3抗体的存在引起的，该抗体被证明是一种仅对λ链具有特异性的免疫球蛋白G。
