临床诊断实验室自身抗体检测的精准度：现实如何？

Precision of autoantibody assays in clinical diagnostic laboratories: What is the reality?

机构信息

Laboratoire d'Immunologie, Hôpital Européen Georges Pompidou, APHP, Paris, France; Cerballiance, 41 rue du bois chaland, 91090 Lisses, France.

Département d'Immunologie, UF immunochimie & autoimmunité, CHU Pitié Salpêtrière-Ch Foix, APHP, Paris, France.

出版信息

Clin Biochem. 2020 Sep;83:57-64. doi: 10.1016/j.clinbiochem.2020.05.019. Epub 2020 Jun 4.

DOI:10.1016/j.clinbiochem.2020.05.019

PMID:32505738

Abstract

BACKGROUND

ISO 15189 accreditation remains a challenge for specialized laboratories. In the field of autoimmunity, beside the crucial problem of absence of standardization, laboratories have to manage the analytical performances of the large panel of assays in terms of sensitivity and specificity, but also on their measurement precision for which no reference values are available on biorepositories.

METHODS

As an initiative of the French EASI (European Autoimmunity Standardization Initiative) group, French clinical diagnostic laboratories were requested to participate in a survey aiming to analyze the coefficients of variation (CVs) of intra-run and inter-run variability obtained with assays quantifying 14 different autoantibodies. Two performance goals corresponding to the 90th percentile and the 50th percentile (lowest CV values reached by 90% and 50% of laboratories respectively) defined for three levels of concentration were calculated. The impact on the assay performances of the number of measurements, of the nature of the internal quality control (IQC) and the type of immunoassay, was also analyzed.

RESULTS

414 and 616 values of intra-run and inter-run CVs were collected, respectively. The 50th percentile performance goals were comprised between 1.0% and 8.9% for the intra-run CVs, and between 1.8% and 14.6% for the inter-run CVs. At 90th percentile, the performance goals were comprised between 3.2% and 13.5% for the intra-run CVs, and between 7.3% and 30.8% for the inter-run CVs. CVs calculated from 10 values were similar to those obtained from more values. Higher imprecision was observed when the antibody levels of the IQC was lower than 2 fold the positive threshold. Commercial IQCs gave lower CVs than IQCs derived from patient samples.

CONCLUSION

Our results allow proposing some acceptability limits for the precision performances of the autoantibody assays, compatible with the reality of life in diagnostic laboratories and clinical care.

摘要

背景

ISO15189 认证对专业实验室来说仍然是一个挑战。在自身免疫领域，除了缺乏标准化这一关键问题外，实验室还必须管理大量检测分析性能，包括灵敏度和特异性，还需要管理其测量精密度，因为生物库中没有参考值。

方法

作为法国 EASI（欧洲自身免疫标准化倡议）小组的一项倡议，要求法国临床诊断实验室参与一项调查，旨在分析定量检测 14 种不同自身抗体的检测分析内和分析间变异性的变异系数（CV）。根据三个浓度水平，计算了对应于 90%和 50%（分别为 90%和 50%的实验室达到的最低 CV 值）的 2 个性能目标。还分析了测量次数、内部质量控制（IQC）的性质和免疫测定类型对检测分析性能的影响。

结果

分别收集了 414 和 616 个分析内和分析间 CV 值。分析内 CV 的 50%性能目标在 1.0%到 8.9%之间，分析间 CV 的 50%性能目标在 1.8%到 14.6%之间。在 90%时，分析内 CV 的性能目标在 3.2%到 13.5%之间，分析间 CV 的性能目标在 7.3%到 30.8%之间。从 10 个值计算的 CV 与从更多值获得的 CV 相似。当 IQC 的抗体水平低于阳性阈值的 2 倍时，观察到更高的不精密度。商业 IQCs 给出的 CV 低于来自患者样本的 IQCs。