Objectives The 2023 ACR/EULAR antiphospholipid syndrome (APS) classification criteria distinguish between anticardiolipin (aCL) or anti-β2-glycoprotein I (aβ2GPI) IgG vs IgM isotypes, having isolate IgM positivity a low weight, insufficient for APS classification, and define aCL and aβ2GPI thresholds based on fixed cut-off values. We aimed to assess the performance of the 2023 ACR/EULAR criteria in a cohort of primary vascular APS patients (PAPS), previously classified according to the Sydney criteria. Additionally, we evaluated the risk of thrombotic recurrence in patients re-classified or not according to the new criteria. Methods PAPS patients meeting the Sydney criteria with previous vascular manifestations followed between 1992 and 2023 were re-evaluated to identify cases that would not be classified as PAPS based on the 2023 ACR/EULAR criteria. Results Our cohort included 205 PAPS patients: 171 met the ACR/EULAR classification criteria, 34 (16.6%) did not due to insufficient score in the laboratory domain caused by isolate IgM positivity (23 patients) or aPL positivity at a titer > 99th percentile but <40 units (11 patients). Notably, 9/34 (26%) patients not confirmed as PAPS had a thrombotic relapse during follow-up. The rate of thrombotic recurrence was similar between patients who fulfilled or not the new criteria. Conclusion Among PAPS patients classified by Sydney criteria, 16.6% did not meet 2023 ACR/EULAR criteria. One quarter of them had a thrombotic relapse, confirming a pro-thrombotic profile. Inappropriately using these criteria as diagnostic in clinical practice could result in the lack of adequate antithrombotic therapy, exposing these patients to the risk of a new thrombotic event.

中文翻译：

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对 2023 年 ACR/EULAR 抗磷脂综合征分类标准的见解：来自 205 例原发性 APS 患者队列的结果


目的 2023 年 ACR/EULAR 抗磷脂综合征 （APS） 分类标准区分抗心磷脂 （aCL） 或抗 β2-糖蛋白 I （aβ2GPI） IgG 与 IgM 同种型，分离株 IgM 阳性权重低，不足以进行 APS 分类，并根据固定临界值定义 aCL 和 aβ2GPI 阈值。我们旨在评估 2023 年 ACR/EULAR 标准在原发性血管 APS 患者 （PAPS） 队列中的表现，这些患者之前根据悉尼标准分类。此外，我们评估了根据新标准重新分类或不重新分类的患者血栓复发的风险。方法 对 1992 年至 2023 年间符合悉尼标准且既往有血管表现的 PAPS 患者进行重新评估，以确定根据 2023 年 ACR/EULAR 标准不会被归类为 PAPS 的病例。结果 我们的队列包括 205 例 PAPS 患者： 171 例符合 ACR/EULAR 分类标准，34 例 （16.6%） 未因分离株 IgM 阳性 （23 例） 或 aPL 阳性在滴度 > 第 99 个百分位但 <40 单位 （11 例患者） 引起的实验室评分不足。值得注意的是，9/34 （26%） 未确诊为 PAPS 的患者在随访期间出现血栓复发。满足或不满足新标准的患者之间的血栓复发率相似。结论 在按 Sydney 标准分类的 PAPS 患者中，16.6% 不符合 2023 年 ACR/EULAR 标准。其中四分之一的患者出现血栓复发，证实了促血栓形成特征。在临床实践中不恰当地使用这些标准作为诊断可能会导致缺乏足够的抗血栓治疗，使这些患者面临新的血栓形成事件的风险。