Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands.
Synapse BV, Maastricht, the Netherlands.
J Thromb Haemost. 2016 Aug;14(8):1530-48. doi: 10.1111/jth.13379. Epub 2016 Aug 11.
Essentials The clinical value of IgM antibodies in thrombotic antiphospholipid syndrome (APS) is debated. By review of literature, we reconsidered the clinical value of IgM antibodies in thrombotic APS. More significant correlations with thrombosis were found for the IgG compared to IgM isotype. Unavailability of paired IgG/IgM results hampers evaluating the added value of IgM positivity. Click to hear Dr de Groot's perspective on antiphospholipid syndrome
Background Despite the update of the classification criteria for the antiphospholipid syndrome (APS), difficulties persist in the identification of patients at risk for thrombosis. Current guidelines include assays detecting IgG/IgM anti-β2 -glycoprotein I and anti-cardiolipin antibodies, although the relevance of IgM antibodies has been debated. Objectives Through a review of the literature from 2001 to 2014, we aimed to formally establish the thrombotic risk stratification potential of IgM as compared with IgG anti-phospholipid antibodies (aPLs). Patients/methods One thousand two hundred and twenty-eight articles were selected by a computer-assisted search of the literature. Of the 177 studies that met our inclusion criteria, the clinical value of IgG/IgM aPLs was established through analysis of odds ratios for thrombosis or percentage of positives in the thrombotic population. Results/conclusions We clearly found more significant correlations with thrombosis for the IgG than for the IgM isotype. Nonetheless, in a minority of studies, significant associations with thrombosis were found for IgM but not IgG antibodies. The unavailability of paired results of IgG and IgM for each separate patient hampers evaluation of the added value of isolated IgM positivity. To fully take advantage of results obtained by future studies, we strongly encourage scientists to provide all studied information per patient. We planned a large multicenter study to investigate clinical associations of isolated/combined positivity for criteria/non-criteria aPLs. Importantly, because of the presence of non-pathogenic aPLs, quantitative assays are characterized by a high false-positivity rate. Optimization of functional assays, such as thrombin generation measuring the whole scheme of coagulation, may help to reduce APS-related morbidity and mortality.
目的 尽管抗磷脂综合征（APS）的分类标准已经更新，但在确定血栓形成风险患者方面仍存在困难。目前的指南包括检测 IgG/IgM 抗-β2-糖蛋白 I 和抗心磷脂抗体的检测方法，尽管 IgM 抗体的相关性一直存在争议。
方法 通过对 2001 年至 2014 年文献的综述，我们旨在正式确定 IgM 与 IgG 抗磷脂抗体（aPLs）相比在血栓形成风险分层中的潜力。
结果 我们发现 IgG 与血栓形成的相关性明显大于 IgM 。尽管如此，在少数研究中，IgM 而不是 IgG 抗体与血栓形成有显著相关性。由于无法为每个单独的患者获得 IgG 和 IgM 的配对结果，因此难以评估单独 IgM 阳性的附加值。为了充分利用未来研究获得的结果，我们强烈鼓励科学家为每位患者提供所有研究信息。我们计划进行一项大型多中心研究，以研究孤立/联合阳性标准/非标准 aPLs 的临床相关性。重要的是，由于存在非致病性 aPLs，定量检测方法的假阳性率很高。优化功能检测，如测量整个凝血方案的凝血酶生成，可能有助于降低 APS 相关发病率和死亡率。
