Kobayashi I, Shoda Y, Kuwabara A, Okajima F, Kondo Y
Department of Laboratory Medicine, Gunma University School of Medicine, Maebashi.
Rinsho Byori. 1994 Sep;42(9):938-42.
The thyroid stimulating antibodies (TSAb) have been widely used as a clinical marker for diagnosis of hyperthyroidism due to Graves' disease. Immunoglobulins (IgG) of Graves' patients as well as TSH is known to stimulate cAMP production in FRTL-5 cells, a cell-line derived from normal rat thyroid. On the other hand, it has been shown that TSH-induced I- efflux in these cells is associated with production of inositolphosphate as well as intracellular Ca2+ increase. An attempt was made to determine whether Graves' IgG also can mimic such TSH action as a cause of Graves' disease. Polyethyleneglycol precipitated serum fraction of Graves' patients were prepared. The cells grown in the presence of TSH were incubated for 3 weeks in a Ham's 10 medium containing 1% calf serum, insulin and hydrocortisone for TSH depletion. After preincubation with 125I-iodide for 50 min to label intracellular iodide, the cells were challenged by serum samples for 1 min. The addition of normal pooled serum hardly affected the I- efflux. The Graves' immunoglobulin G fractions stimulated I- efflux dose-dependently. The mean potency of 12 patient's sera relative to the values of the pooled serum as 100% was 217 +/- 56.4%, which was significantly higher (p < 0.001) than that for 8 normal subjects (110 +/- 16.1%). The results obtained herein indicate that IgG of Graves' patients activate both adenylate aclase-cAMP system and a phospholipid-Ca2 system. I- efflux stimulating immunoglobulins (IESI) activity is a useful marker in making a diagnosis or determining a remission of hyperthyroidism due to Graves' disease.
促甲状腺素抗体（TSAb）已被广泛用作诊断格雷夫斯病所致甲状腺功能亢进的临床标志物。已知格雷夫斯病患者的免疫球蛋白（IgG）以及促甲状腺激素（TSH）可刺激FRTL-5细胞（一种源自正常大鼠甲状腺的细胞系）中的环磷酸腺苷（cAMP）生成。另一方面，已表明这些细胞中TSH诱导的碘外流与肌醇磷酸的产生以及细胞内钙离子增加有关。有人试图确定格雷夫斯病的IgG是否也能模拟TSH的这种作用，作为格雷夫斯病的病因。制备了聚乙二醇沉淀的格雷夫斯病患者血清组分。将在TSH存在下生长的细胞在含有1%小牛血清、胰岛素和氢化可的松的哈姆氏10培养基中孵育3周以耗尽TSH。在用125I-碘化物预孵育50分钟以标记细胞内碘后，用血清样本刺激细胞1分钟。添加正常混合血清几乎不影响碘外流。格雷夫斯病免疫球蛋白G组分剂量依赖性地刺激碘外流。12例患者血清相对于混合血清值（设为100%）的平均效力为217±56.4%，显著高于8例正常受试者（110±16.1%）（p<0.001）。本文获得的结果表明，格雷夫斯病患者的IgG激活腺苷酸环化酶-cAMP系统和磷脂-Ca2+系统。碘外流刺激免疫球蛋白（IESI）活性是诊断或确定格雷夫斯病所致甲状腺功能亢进缓解的有用标志物。
