Passath A, Leb G, Goebel R, Warnkross H
Nuklearmedizin. 1982 Oct;21(5):200-8.
In accordance with the TRH-test two generations of FT4-immunoassays were checked in order to find a substitute for the free thyroxine index. The euthyroid reference range of FT4 was between 0.69-1.91 ng/dl using GammaCoat (Clinical Assays) and 0.94-2.29 ng/dl using Amerlex (Amersham), respectively. In the euthyroid range, FT4 as measured by Amerlex was, on the average, 47% higher than the value obtained by using GammaCoat. During treatment by thyroid hormones and TSH-suppression following TRH application, Amerlex FT4 values were up to 59% higher than the GammaCoat FT4 values. During replacement therapy, the FT4 values obtained by Amerlex were within the euthyroid reference range so that a differentiation between substitution and suppression appears to be possible by means of determining FT4. An overdose was assessed by simultaneous determination of T3 and FT4. According to our results Amerlex FT4 meets the requirements of a modern radioimmunoassay and is suitable as a substitute for the free thyroxine index. For this purpose the earlier method of determining FT4 (GammaCoat) does not seem suitable.
根据促甲状腺激素释放激素（TRH）试验，对两代游离甲状腺素（FT4）免疫测定法进行了检查，以寻找游离甲状腺素指数的替代方法。使用GammaCoat（临床检测）时，FT4的甲状腺功能正常参考范围为0.69 - 1.91 ng/dl，使用Amerlex（阿美仙）时为0.94 - 2.29 ng/dl。在甲状腺功能正常范围内，Amerlex测定的FT4平均比使用GammaCoat获得的值高47%。在应用TRH后进行甲状腺激素治疗和促甲状腺激素（TSH）抑制期间，Amerlex的FT4值比GammaCoat的FT4值高出59%。在替代治疗期间，Amerlex获得的FT4值在甲状腺功能正常参考范围内，因此通过测定FT4似乎可以区分替代和抑制情况。通过同时测定三碘甲状腺原氨酸（T3）和FT4来评估用药过量情况。根据我们的结果，Amerlex FT4符合现代放射免疫测定的要求，适合作为游离甲状腺素指数的替代方法。为此，早期测定FT4的方法（GammaCoat）似乎不合适。
