Analytical Performance and Clinical Utility of Thyroid Function Tests

在一项多机构合作研究中，我们评估了甲状腺激素抑制治疗良性多结节甲状腺疾病的潜在临床应用价值。这项研究是使用我们之前开发的定量研究综合方法进行的。这一方法包括系统回顾相关临床研究和专家意见的文献，对选定的介入研究进行荟萃分析，调查国立卫生研究院内分泌科医生对良性多结节甲状腺疾病假想患者的治疗决策，对接受左旋甲状腺素抑制治疗的NIH患者进行实践验证，以及应用Hill？S标准评估甲状腺抑制治疗和良性结节消退之间的因果关系。与我们早期对甲状腺抑制治疗良性孤立性甲状腺结节效果的观察相似，我们发现良性多结节甲状腺疾病的一部分患者对这种药物治疗有反应，结节大小在临床上显著减小。因此，在没有服用左旋甲状腺素禁忌症(S)的良性多结节甲状腺疾病患者中，有必要进行这种疗法的初步试验。在另一项研究中，我们评估了一例肾病综合征患者需要增加左旋甲状腺素替代治疗才能达到正常甲状腺状态的病例。我们用不同的非同位素方法分析了不同采血管对游离甲状腺激素(FT4)、游离碘甲状腺原氨酸(FT3)和促甲状腺激素(TSH)测定的影响。在某些检测中，我们只观察到一种类型的采集管的临床显著效果。然而，研究结果表明，在用于甲状腺功能测试之前，有必要对这些管子进行常规评估。

In a multi-institute collaborative study, we assessed the potential clinical utility of thyroid hormone suppression therapy on benign multinodular thyroid disease. The study was performed using our previously developed method of quantitative research synthesis. This approach involved systematic review of the literature for relevant clinical studies and expert opinions, meta-analysis of selected interventional studies, surveys of NIH endocrinology practitioners for therapeutic decisions in hypothetic patients with benign multinodular thyroid disease, practice validation in NIH patients treated with levothyroxine suppression for benign multinodular thyroid disease, and application of Hill?s criteria to assess causality between thyroid suppression therapy and regression of benign nodules. Similar to our earlier observation for the effect of thyroid suppression therapy on benign solitary thyroid nodules, we found that a subset of patients with benign multinodular thyroid disease responded to this medical therapy with clinically significant reduction in nodule size. Consequently, an initial trial of this therapy is warranted in patients with benign multinodular thyroid disease in the absence of contraindication(s) to levothyroxine administration. In another study, we evaluated a case in which increased doses of levothyroxine replacement therapy were required to achieve euthyroid status in a patient with nephrotic syndrome. The clinical picture thus mimicked an "inappropriate" thyroid-stimulating hormone (TSH) secretion syndrome.We analyzed the effect of various blood collection tubes on the measurements of free thyroxine (FT4), free iodothyronine (FT3), and TSH (thyroid-stimulating hormone or thyrotropin) with different nonisotopic methods. We observed clinically significant effects only with one type of collection tube on some assays. Nevertheless, the findings indicate that routine evaluation of these tubes is warranted before their use for thyroid function testing.