内分泌
词汇介绍
拓展阅读
解析
thyroglobulin 英/,θaɪrə(ʊ)'glɒbjʊlɪn/ 美/,θaɪro'ɡlɑbjəlɪn/
释 义 n. [生化] 甲状腺球蛋白
例 句 Objective: To investigate the relations between level of thyroglobulin and thyroid stimulating hormone in pregnant women. 目的:探讨孕妇甲状腺球蛋白水平和促甲状腺素水平之间的关系。
antibody 英 /'æntɪbɒdɪ/ 美 /'æntɪ'bɑdi/
释 义 n. [免疫] 抗体
例 句 It marshals the same antibody response to both of them. 它对两者作出的抗体反应都是一样的。
概述
概述
甲状腺球蛋白(Tg)是一种660 kDa大小的二聚体的蛋白质,甲状腺球蛋白约占甲状腺蛋白质含量的一半。人TG(HTG)是亚单位的同二聚体,每个亚单位含有合成的2768个氨基酸(短信号肽可以从成熟蛋白的N-末端除去)。
功能
甲状腺激素合成,甲状腺球蛋白从粗面内质网生产,直到蛋白水解释放甲状腺激素。甲状腺使用Tg来产生甲状腺激素、甲状腺素(T4)和 三碘甲腺原氨酸(T3)。三碘甲腺原氨酸3,5,3'三碘甲腺原氨酸的活性形式在甲状腺内和周围由5'-脱碘酶(其被称为四碘甲腺原氨酸5'脱碘酶)产生。据推测,Tg和甲状腺也是碘对所有身体需要的重要储存,特别是对于许多碘浓缩器官,如乳房,胃,唾液腺,胸腺,脉络丛和脑脊液等(见碘)在生物学)。Tg由甲状腺上皮细胞产生,称为甲状腺细胞,形成球形卵泡。Tg被分泌并储存在滤泡腔中。通过与甲状腺过氧化物酶 的反应,碘与甲状腺球蛋白分子中的酪氨酸残基共价结合,形成单碘酪氨酸(MIT)和二碘酪氨酸(DIT)。甲状腺素是通过组合两个DIT 部分产生的。三碘甲腺原氨酸通过组合一个MIT分子和一个DIT分子而产生。卵泡胶体(Tg)的小球被内吞(激素(TSH)介导的)和蛋白酶在溶酶体消化碘化甲状腺球蛋白,甲状腺细胞的细胞质中释放T3和T4。然后通过未知机制将T3和T4跨过(TSH介导的)基底外侧甲状腺细胞膜转运到血流中,同时将溶酶体再循环回到滤泡腔。
临床意义
甲状腺球蛋白的代谢发生在肝脏中并通过甲状腺再循环蛋白质。循环甲状腺球蛋白的半衰期为65小时。甲状腺切除术后,甲状腺球蛋白水平可能需要数周才能检测不到。甲状腺球蛋白水平可在甲状腺移除后定期测试数周或数月。甲状腺球蛋白水平变得不可检测(甲状腺切除术后),可以连续监测水平。随后甲状腺球蛋白水平升高表明乳头状或滤泡性甲状腺癌复发。换句话说,血液中甲状腺球蛋白水平的升高可能是甲状腺癌细胞正在生长和/或癌症正在扩散的迹象。因此,血液中的甲状腺球蛋白水平主要用作某些甲状腺癌(特别是乳头状或滤泡性甲状腺癌)的肿瘤标志物。甲状腺球蛋白不是由髓质或间变性甲状腺癌产生的。因此经常在甲状腺癌治疗后进行简单的血液测试测试甲状腺球蛋白水平。
消融甲状腺乳头状癌患者甲状腺球蛋白抗体的时间趋势: 我们能预测转阴率吗?
发表时间:2019-04-12
影响指数:3.7
作者: Eyun Songa
期刊:Oral Oncology
Persistence of thyroglobulin antibody (TgAb) during follow-up in patients with differentiated thyroid carcinoma (DTC) after complete removal of the thyroid tissue is a challenge for clinicians since TgAb can interfere with thyroglobulin (Tg) measurement which is the most sensitive marker for remnant thyroid. TgAb is present in 17%–25% of patients with DTC and is an important factor for assessing the dynamic risk stratification, as proposed by Tuttle et al. and adopted by the guidelines of the American Thyroid Association. According to this classification, patients with DTC who underwent total thyroidectomy (TT) followed by radioiodine (RAI) ablation and are positive for TgAb exhibit prognoses similar to those observed between the “excellent response” and “structural incomplete response” groups. However, long-term data regarding the natural course of TgAb titers in these patients (i.e., the disappearance of TgAb and factors affecting the timing of negative conversion) are limited. Previous studies have reported that a median of 2–3 years is required for negative conversion of TgAb. The thyroid gland is the only source of Tg and TgAbs are mostly produced by lymphocytes infiltrating the gland; therefore, complete elimination of the thyroid tissue by TT and subsequent RAI ablation of the remnant thyroid tissue results in a progressive decline in TgAb levels and eventually its disappearance. However, certain patients may remain positive for TgAb years after ablation even in the absence of evidence of structural disease (no evidence of structural disease, NESD). There are evidences that increased or stationary TgAb titers may be associated with persistence/recurrence of thyroid cancer. However, there is no consensus on whether or when to performe extensive and/or frequent imaging investigations to detect evidence for structural disease in patients persistently positive for TgAb during follow-up. To clarify this issue, the present study evaluated the time trends of TgAb in patients with papillary thyroid carcinoma (PTC) and NESD, who previously underwent TT and subsequent RAI ablation and aimed to identify predictive factors for the rate of negative conversion of TgAb.
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