Multicentre comparison of free thyroid hormones immunoassays: the Immunocheck study
Multicentre comparison of free thyroid hormones immunoassays: the Immunocheck study
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DOI：
10.1515/cclm.2011.647
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发表时间：
2011-10-01
影响因子：
6.8
通讯作者：
Clerico, Aldo
中科院分区：
文献类型：
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作者：
Giovannini, Stefania;Zucchelli, Gian Carlo;Clerico, Aldo
背景：为了评估不同游离甲状腺激素(FT)免疫分析方法的测量值和分析性能是否仍存在很大的差异，我们考虑了名为免疫检查的外部质量评估(EQA)计划的结果。方法：EQA免疫检查研究招募了约1000个参与实验室，对分布在三个年度周期(2007、2008和2009)的54个质量控制样本进行了测量。参与实验室的FT3和FT4分别产生了30,476和31,351个结果。结果：在EQA周期中恢复的结果允许估计测定的不精密度(即方法内和实验室间的变异性)。平均而言，游离三碘甲腺原氨酸(FT3)和游离甲状腺激素(FT4)浓度较低的对照样品的不精密度值(CV%)高于那些水平在正常范围或以上的样品。通过计算不同方法测量的结果与所有收集结果的平均值(即共识平均值)之间的百分比差异(即百分比偏差值)来评估不同方法产生的结果之间的一致性。结论：我们的研究结果表明，不同的游离甲状腺激素免疫测定方法之间的测量值仍然存在较大的差异。事实上，FT3和FT4测量的一些免疫分析显示，与普遍的平均值>；20%相比，有百分比的偏差。实验室应告知临床医生所用方法的分析性能和参考限值。此外，临床医生应避免在患者的随访中使用不同的方法。
Background: In order to evaluate whether there is still present a very large variability in measured values and analytical performance among different free thyroid (FT) hormone immunoassays, we considered the results derived from an External Quality Assessment (EQA) scheme, named Immunocheck.Methods: The EQA Immonocheck study enrolled about 1000 participant laboratories, which measured the 54 quality control samples distributed in the three annual cycles (2007, 2008 and 2009). Participant laboratories produced a total of 30,476 results for FT3 and 31,351 for FT4, respectively.Results: The results recovered during the EQA cycles allowed the estimation of assay imprecision (i.e., within-method and between-laboratories variability). On average, control samples with lower free triiodothyronine (FT3) and free thyroxine (FT4) concentrations showed higher imprecision values (CV%) than those with levels within or above the normal range. The agreement among the results produced by different methods was estimated by computing the percent differences (i.e., percent bias values) between the concentrations measured by the methods and the mean of all collected results (i.e., consensus mean).Conclusions: The results of our study demonstrate that a large variability in measured values is still present among different free thyroid hormone immunoassays. Indeed, some immunoassays for both FT3 and FT4 measurement showed percent bias values compared to the consensus mean >20%. Laboratories should inform the clinicians about analytical performance and reference limits of the method used. Furthermore, the clinicians should avoid the use of different methods in the follow-up of patients.