Noubouossie D, Valsamis J, Corazza F, Rozen L, Debaugnies F, Demulder A
Laboratory of Hematology and Haemostasis, CHU Brugmann, Brussels, Belgium.
Acta Clin Belg. 2012 May-Jun;67(3):184-9. doi: 10.2143/ACB.67.3.2062653.
Detection of anticardiolipin antibodies (ACA) is an independent laboratory criterion for diagnosis of antiphospholipid syndrome (APS). Alternative methods to ELISA were recently developed such as automated chemiluminescence immunoassay (CLIA).
We compared a CLIA to an ELISA kit for the detection of IgG isotype of ACA. 87 routine samples from 75 patients suspected of having APS were tested using each method. Cut-off values were calculated in our laboratory for each test using 99th percentile of 50 normal controls.
Cut-off values were >20 GPL for ELISA and > 2 GPL for CLIA. Overall agreement (OA), agreement for positive (AP) and agreement for negative (AN) cases were 56.3%, 49.2% and 77.2% respectively. Most discrepant results were positive with ELISA and negative with CLIA. However, OA, AP and AN increased to 82.1%, 84.6% and 80% respectively when CLIA was compared to the repeated ELISA performed at least 12 weeks later. When correlated with APS-related clinical background, CLIA showed lower sensitivity, higher specificity and higher likelihood ratio (LR) as compared to first ELISA whereas these parameters were similar to those of the repeated ELISA. No association was found between any test results and APS-related clinical background of the patients. Using our own cut-off value (> 2GPL), sensitivity, specificity and LR of CLIA to identify patients with APS were respectively 100%, 72.3% and 3.6. A ROC curve showed that at 7.5 GPL cut-off value, specificity and LR improved to 91.1% and 11.25 respectively, without affecting sensitivity. A strong correlation was observed between CLIA results and APS (Chi2 = 12.25; p < 0.001).
The performance of CLIA is as good as a repeated ELISA test to detect IgG ACA in suspected APS patients. It is fully automated, which represents several advantages over semi-manual ELISA techniques for its implementation in a routine laboratory.
抗心磷脂抗体（ACA）检测是抗磷脂综合征（APS）诊断的一项独立实验室标准。近期开发了酶联免疫吸附测定（ELISA）的替代方法，如自动化化学发光免疫分析（CLIA）。
我们比较了一种用于检测ACA IgG同种型的CLIA试剂盒与一种ELISA试剂盒。使用这两种方法对来自75例疑似患有APS患者的87份常规样本进行检测。在我们实验室中，使用50名正常对照的第99百分位数为每种检测方法计算临界值。
ELISA的临界值>20 GPL，CLIA的临界值>2 GPL。总体一致性（OA）、阳性一致性（AP）和阴性一致性（AN）分别为56.3%、49.2%和77.2%。大多数差异结果为ELISA阳性而CLIA阴性。然而，当将CLIA与至少12周后进行的重复ELISA比较时，OA、AP和AN分别增至82.1%、84.6%和80%。当与APS相关临床背景相关联时，与首次ELISA相比，CLIA显示出较低的敏感性、较高的特异性和较高的似然比（LR），而这些参数与重复ELISA的参数相似。未发现任何检测结果与患者的APS相关临床背景之间存在关联。使用我们自己的临界值（>2 GPL），CLIA识别APS患者的敏感性、特异性和LR分别为100%、72.3%和3.6。一条ROC曲线显示，在临界值为7.5 GPL时，特异性和LR分别提高到91.1%和11.25，而不影响敏感性。观察到CLIA结果与APS之间存在强相关性（χ2 = 12.25；p < 0.001）。
在疑似APS患者中检测IgG ACA时，CLIA的性能与重复ELISA检测一样好。它是全自动的，与半手工ELISA技术相比，在常规实验室实施具有多个优势。
