Christofides N D, Sheehan C P
Cardiff Laboratories, Kodak Clinical Diagnostics, Ltd., Amersham, UK.
Clin Chem. 1995 Jan;41(1):24-31.
The technical and diagnostic performance of the Amerlite-MAB enhanced luminescence assay for free thyroxine (FT4) was assessed in a multicenter evaluation trial. The euthyroid central 95% reference range for FT4 (1393 subjects) was 11.5-27.7 pmol/L (by cumulative frequency plot with two-tailed 2.5% cutoffs). Results (y) agreed with those of similar radioactive method (Amerlex-MAB FT4) (x): y = 1.06 x + 0.54, Sylx = 335.5, n = 235). Mean within-assay precision (CV) in six centers was 5.7% at 6 pmol/L and 2.6% at 51 pmol/L FT4; between-assay precision (CV) was 7.2% and 3.6%, respectively. Diagnostic performance was assessed in all patient groups usually encountered, including those with nonthyroidal illness and extreme binding-protein anomalies. In elderly euthyroid subjects, the proportion of above-normal FT4 values exceeded that in younger age-groups. These increases often accompanied normal estimates of thyrotropin and, in some cases, might have arisen by interference from medication that is taken more often by the elderly.
在一项多中心评估试验中，对用于游离甲状腺素（FT4）检测的Amerlite - MAB增强发光测定法的技术和诊断性能进行了评估。FT4的甲状腺功能正常中心95%参考范围（1393名受试者）为11.5 - 27.7 pmol/L（通过带有双侧2.5%临界值的累积频率图）。结果（y）与类似放射性方法（Amerlex - MAB FT4）的结果（x）一致：y = 1.06x + 0.54，Sylx = 335.5，n = 235）。六个中心在FT4为6 pmol/L时的批内精密度均值（CV）为5.7%，在51 pmol/L时为2.6%；批间精密度（CV）分别为7.2%和3.6%。在所有常见患者群体中评估了诊断性能，包括患有非甲状腺疾病和极端结合蛋白异常的患者群体。在老年甲状腺功能正常的受试者中，FT4值高于正常的比例超过了年轻年龄组。这些升高常常伴随着促甲状腺激素的正常估计值，在某些情况下，可能是由老年人更常服用的药物干扰引起的。
