游离甲状腺素免疫测定法的检测偏差

Studies on Biases in Free Thyroxine Immunoassays.

目的研究血清甲状腺素结合能力对游离甲状腺素免疫测定法检测偏差的影响。方法以平衡透析法为基准,以16位孕期超过6个月的孕妇和32位住院患者为对象,研究免疫测定法的检测偏差。结果 16位孕期超过6个月的孕妇具有高血清甲状腺素结合能力,15位住院患者具有正常血清甲状腺素结合能力,另外17位住院患者具有低血清甲状腺素结合能力。对于正常血清甲状腺素结合能力组和高血清甲状腺素结合能力组,各种免疫测定法与平衡透析法的检测结果之间不存在显著性差异(P>0.05或 P>0.01)。对于低血清甲状腺素结合能力组,各种免疫测定法与平衡透析法的检测结果之间存在显著性差异(P<0.01),平均偏差均为负值。结论血清甲状腺素结合能力影响游离甲状腺素免疫测定法的检测偏差。临床诊断时,必须密切关注测定方法和患者的具体情况,以正确理解其检测结果。对于孕妇,甚至完全必要专门确定其参考值范围。

Objective To study the effects of the serum thyroxine - binding capacity on the biases in free thyroxine immunoassays. Methods Based on direcf equilibrium free ftyroxine assay, 16 women in the last 3 months of pregnancy and 32 in patients as subjects, to probe biases of immuncassays. Results The women in the last 3 months of pregnancy was classified into the high serum thyroxine - binding capacity group, 15 in patients into the normal serum thyroxine- binding capacity group, and another 17 in patients into the low serum thyroxine- binding capacity group. No significant bias was found between the investigated immunoassays and the direct equilibrium free thyroxine assay in the high serum thyrexine - binding capacity group and the normal serum thyroxine - binding capacity group （ P 〉 0.05 or P 〉 0.01） .In the low serum thyroxine-binding capacity group, all investigated immunoassays showed a significant （ P 〈 0.01 ） and marked negative bias. Conclusions The investigated free thyroxine immunoassays showed serum thyroxine- binding capacity dependent biases. To interpret the results, clinicians should be aware of the method used and the conditions of the patients. It is necessary to define the reference intervals for women in the last 3 months of pregnancy.