Department of Clinical Chemistry and Hematology, University Medical Center, Utrecht, the Netherlands.
J Thromb Haemost. 2011 Jan;9(1):149-53. doi: 10.1111/j.1538-7836.2010.04068.x.
Antiphospholipid syndrome (APS) is diagnosed by the simultaneous presence of vascular thrombosis and/or pregnancy morbidity and detection of antiphospholipid antibodies in plasma.
We have shown that prolongation of clotting time by anti-beta2-glycoprotein I (beta2GPI) antibodies correlates better with thrombosis than a positive classic lupus anticoagulant (LAC) assay in a single center study. To confirm or falsify this finding we have conducted a multicenter study.
In 325 LAC-positive samples, we found that the beta2GPI-dependent LAC correlated 2.0 times better with thrombosis than the classic LAC assay. Although significant, this was a minimal improvement compared with the 'classic' LAC. It was published that calcium influences the behavior of anti-beta2GPI antibodies in coagulation assays. To investigate whether calcium plays a role in the present study, we divided the patient population into two groups: (i) blood was collected in 0.109 m sodium citrate and (ii) blood was drawn in 0.129 m sodium citrate as anticoagulant. We found that a positive result with the beta2GPI-dependent LAC assay correlated better with thrombosis [odds ratio (OR): 3.3, 95% confidence interval (CI) 1.9-5.8] when 0.109 m sodium citrate was used compared with 0.129 m sodium citrate (OR: 0.4, 95% CI 0.1-1.1).
We were able to confirm in an international multicenter study that a positive result in a beta2GPI-dependent LAC assay correlates better with thrombosis than the classic LAC assay, but that the assay needs further study as it is sensitive to external factors such as the sodium citrate concentration used as anticoagulant in the test sample.
抗磷脂综合征(APS)的诊断标准为同时存在血管血栓形成和/或妊娠并发症,以及血浆中存在抗磷脂抗体。
我们曾在一项单中心研究中表明,抗β2-糖蛋白 I(β2GPI)抗体延长凝血时间与血栓形成的相关性优于经典狼疮抗凝物(LAC)检测,为了证实或否定这一发现,我们进行了一项多中心研究。
在 325 例 LAC 阳性样本中,我们发现β2GPI 依赖性 LAC 与血栓形成的相关性比经典 LAC 检测高 2.0 倍。虽然这一相关性具有统计学意义,但与“经典”LAC 相比,这只是略有改善。曾有报道称,钙离子会影响抗β2GPI 抗体在凝血检测中的行为。为了研究钙离子是否在本研究中发挥作用,我们将患者人群分为两组:(i)使用 0.109 m 柠檬酸钠采集血液,(ii)使用 0.129 m 柠檬酸钠作为抗凝剂采集血液。我们发现,与使用 0.129 m 柠檬酸钠相比,当使用 0.109 m 柠檬酸钠时,β2GPI 依赖性 LAC 检测阳性结果与血栓形成的相关性更好[比值比(OR):3.3,95%置信区间(CI)1.9-5.8]。
我们能够在一项国际多中心研究中证实,β2GPI 依赖性 LAC 检测阳性结果与血栓形成的相关性优于经典 LAC 检测,但该检测方法需要进一步研究,因为它对外界因素敏感,例如在检测样本中用作抗凝剂的柠檬酸钠浓度。