A Clinical Approach for Defining the Threshold between Low and Medium Anti-Cardiolipin Antibody Levels for QUANTA Flash Assays
A Clinical Approach for Defining the Threshold between Low and Medium Anti-Cardiolipin Antibody Levels for QUANTA Flash Assays
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DOI：
10.3390/antib5020014
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发表时间：
2016-06-01
期刊：
影响因子：
4.7
通讯作者：
Mahler, Michael
中科院分区：
文献类型：
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作者：
Lakos, Gabriella;Bentow, Chelsea;Mahler, Michael
诊断抗磷脂综合征（APS）的抗心磷脂（aCL）和抗2-糖蛋白I抗体（a2 GPI）的低和中等抗体水平之间的阈值仍然是一个讨论的问题。我们的目标是创建一个基于临床方法确定ACL抗体方法的低/中抗体临界值的方案，并利用它建立QUANTA Flash ACL荧光免疫测定（CIA）结果的临床相关低/中阈值。该研究包括来自原发性APS（n = 70）、继发性APS（n = 42）、疑似APS（n = 36）、无APS的系统性红斑狼疮（SLE）（n = 96）和其他结缔组织疾病（n = 44）患者的288份样本。使用QUANTA Flash CIA以及沿着传统酶联免疫吸附试验（ELISA）（QUANTA Lite）检测所有样本的IgG和IgM aCL抗体。QUANTA Flash aCL IgG和IgM检测试剂盒的检测试剂盒特异性低/中阈值（即，基于临床性能和与QUANTA Lite ELISA的比较，分别将40 GPL和MPL单位的当量确定为95和31荧光单位（CU）。与使用测定临界值生成的结果获得的一致性相比，当使用平台特异性低/中抗体阈值时，CIA和ELISA测定结果之间的一致性大幅提高：IgG aCL的Cohen's kappa从0.85增加到0.91，而IgM aCL结果从0.59增加到0.75。本研究描述了一种建立aPL抗体检测的低/中抗体阈值的临床方法，并成功地将其分别定义为95和31 CU，作为QUANTA Flash aCL IgG和IgM结果的低/中临界点。本研究可作为实验室在实施新的aPL抗体检测时希望建立适当的低/中aPL抗体阈值的模型。
The threshold between low and medium antibody levels for anticardiolipin (aCL) and anti-2 glycoprotein I antibodies (a2GPI) for the diagnosis of antiphospholipid syndrome (APS) remains a matter of discussion. Our goal was to create a protocol for determining the low/medium antibody cut-off for aCL antibody methods based on a clinical approach, and utilize it to establish the clinically-relevant low/medium threshold for QUANTA Flash aCL chemiluminescent immunoassay (CIA) results. The study included 288 samples from patients with primary APS (n = 70), secondary APS (n = 42), suspected APS (n = 36), systemic lupus erythematosus (SLE) without APS (n = 96) and other connective tissue diseases (n = 44). All samples were tested for IgG and IgM aCL antibodies with QUANTA Flash CIA, along with traditional enzyme-linked immunosorbent assays (ELISAs) (QUANTA Lite). The assay specific low/medium threshold for QUANTA Flash aCL IgG and IgM assays (i.e., the equivalent of 40 GPL and MPL units) was established as 95 and 31 chemiluminescent units (CU), respectively, based on clinical performance and comparison to QUANTA Lite ELISAs. Agreement between CIA and ELISA assay results improved substantially when the platform-specific low/medium antibody threshold was used, as compared to agreement obtained on results generated with the assay cutoff: Cohen's kappa increased from 0.85 to 0.91 for IgG aCL, and from 0.59 to 0.75 for IgM aCL results. This study describes a clinical approach for establishing the low/medium antibody threshold for aPL antibody assays, and successfully employs it to define 95 and 31 CU, respectively, as the low/medium cut point for QUANTA Flash aCL IgG and IgM results. This study can serve as a model for labs wishing to establish the appropriate low/medium aPL antibody threshold when implementing new aPL antibody assays.