Reiners C, Hoffmann R, Moll E, Baum K, Becker W, Eilles C, Gerhards W, Schick F, Spiegel W, Wiedemann W
Nuklearmedizin. 1983 Dec;22(6):273-87.
Part II of the study concerning the clinical applicability of direct and indirect parameters for free thyroxine evaluates the diagnostic accuracy of the FT4-RIAs ImmoPhase, GammaCoat, Liquisol, Amerlex and LisoPhase in relation to FT4 index and T4/TBG ratio. This comparison of methods is done on a thoroughly classified collection (n = 640) of patients with normal and impaired thyroid function including patients with binding protein anomalies (pregnancy, estrogen-medication, phenytoin therapy, renal protein loss). FT4 normal ranges of a given kit harmonize well with data of the manufacturers and of the literature. On the other hand, the normal ranges of the various kits are not comparable. The differentiation of euthyroidism from hyper- or hypothyroidism can be made without problems using any of these methods, with the exception of the FT4-RIA GammaCoat. As expected, patients with euthyroid goiter show, on the average, slightly lower parameters for FT4. In pregnancy all direct and indirect parameters for FT4 have a tendency to lower values after the first trimester. This trend is most distinct for the T4/TBG ratio. A weak negative correlation of FT4 parameters with basal TSH, which does not exceed the upper normal range, however, can be interpreted in the sense of a relative hypothyroxinemia. Under contraceptive estrogen medication FT4 parameters do not fall outside the normal range, with the exception of the FT4-RIA ImmoPhase assay which yields a significantly increased frequency of high FT4 levels. On therapy with phenytoin FT4 values are generally lower than in controls. FT4 parameters in patients with renal protein loss of more than 2 g daily do not behave uniformly. While three of the FT4-RIAs tested (ImmoPhase, GammaCoat, Amerlex) show a tendency to lower values, the results of the remaining FT4 parameters do not differ significantly from the distribution of normals. The study leads to the conclusion that indirect FT4 parameters are still useful in the diagnosis of thyroid function; currently available FT4 radioimmunoassays may yield comparable results. With regard to the varying quality of the various commercial test kits, the choice between FT4-RIAs and indirect FT4 parameters does not depend primarily on clinical but on technical viewpoints.
关于游离甲状腺素直接和间接参数临床适用性的研究第二部分，评估了ImmoPhase、GammaCoat、Liquisol、Amerlex和LisoPhase这几种游离甲状腺素放射免疫分析（FT4 - RIA）方法相对于FT4指数和T4/TBG比值的诊断准确性。这种方法比较是在一组经过全面分类的患者（n = 640）中进行的，这些患者甲状腺功能正常或受损，包括患有结合蛋白异常（妊娠、雌激素治疗、苯妥英治疗、肾性蛋白丢失）的患者。特定试剂盒的FT4正常范围与制造商和文献数据吻合良好。另一方面，各种试剂盒的正常范围不可比。除了FT4 - RIA GammaCoat方法外，使用这些方法中的任何一种都能毫无问题地区分甲状腺功能正常与甲状腺功能亢进或减退。正如预期的那样，甲状腺功能正常的甲状腺肿患者平均FT4参数略低。在妊娠期间，所有FT4的直接和间接参数在孕早期后都有降低的趋势。这种趋势在T4/TBG比值上最为明显。FT4参数与基础促甲状腺激素（TSH）呈弱负相关，但未超过正常范围上限，然而，这可以被解释为相对甲状腺素血症。在使用避孕雌激素治疗时，FT4参数除了ImmoPhase法FT4 - RIA检测出现高FT4水平频率显著增加外，均未超出正常范围。在苯妥英治疗期间，FT4值通常低于对照组。每日肾性蛋白丢失超过2克的患者的FT4参数表现并不一致。虽然所测试的三种FT4 - RIA（ImmoPhase、GammaCoat、Amerlex）显示有降低值的趋势，但其余FT4参数的结果与正常分布无显著差异。该研究得出结论，间接FT4参数在甲状腺功能诊断中仍然有用；目前可用的FT4放射免疫分析可能产生可比的结果。鉴于各种商业检测试剂盒质量不同，在FT4 - RIA和间接FT4参数之间的选择主要不取决于临床观点，而是技术观点。
