The interest of extra-criteria antiphospholipid antibodies is growing, especially in patients negative for conventional antibodies. In this study we aimed to assess the clinical utility of anti-phosphatidyl-serine/prothrombin antibodies (aPS/PT) testing in patients negative for Beta2-Glycoprotein 1(β2GPI)-dependent tests, for identifying antiphospholipid syndrome (APS) patients that developed cerebrovascular events (CVE). When screening APS patients attending our center, out of 119 aPS/PT IgG/IgM-positive patients, thus patients negative for aβ2GPI and aCL, 42 patients (35%) tested negative for β2GPI-dependent tests and were tested with thrombin generation assay (TGA). Ten patients (24%), with isolated aPS/PT IgG/IgM, had a history of CVE. Lupus anticoagulant (LA)-positive test was more frequently observed in patients with CVE (8/22 vs. 2/20; p = 0.045). Out of the 10 patients who experienced CVE, 3 patients were aPS/PT IgG positive (all LA positive), and 8 patients were aPS/PT IgM positive (6/8 LA positive). One patient was positive for both aPS/PT IgG and IgM. LA-positive patients had only high titers of aPS/PT IgG/IgM, all of them being ≥ 80 U/ml, while the 2 LA-negative patients were aPS/PT IgM positive with medium titers [40–60 U/ml]. LA-positive patients had significantly altered TGA profile when compared to those who were LA negative, considering all TGA parameters. LA-positive patients had significantly higher tLag (8.4 ± 3.3 min vs. 6.6 ± 1.8 min; p = 0.046), higher tPeak (14 ± 4.3 min vs. 11 ± 2.7 min; p = 0.015) and lower Peak (207 ± 152 nM vs. 356.3 ± 104.7 nM; p < 0.001) and lower AUC (2109.7 ± 1006.9 nM vs. 2772.5 ± 776.8 nM; p = 0.033). The use of aPS/PT might be of help in identifying patients with CVE and APS, as also confirmed by TGA testing.

人们对超标准抗磷脂抗体的兴趣日益浓厚，特别是对于常规抗体呈阴性的患者。在这项研究中，我们的目的是评估抗磷脂酰丝氨酸/凝血酶原抗体 (aPS/PT) 检测对 β2-糖蛋白 1 (β2GPI) 依赖性检测呈阴性的患者的临床效用，以识别出现抗磷脂综合征 (APS) 的患者。脑血管事件（CVE）。在对我们中心的 APS 患者进行筛选时，在 119 名 aPS/PT IgG/IgM 阳性患者（即 aβ2GPI 和 aCL 阴性患者）中，42 名患者 (35%) 的 β2GPI 依赖性测试呈阴性，并进行了凝血酶生成测定（热分析）。 10 名分离出 aPS/PT IgG/IgM 的患者 (24%) 有 CVE 病史。狼疮抗凝剂 (LA) 阳性检测在 CVE 患者中更常见（8/22 比 2/20； p = 0.045）。在经历 CVE 的 10 名患者中，3 名患者为 aPS/PT IgG 阳性（均为 LA 阳性），8 名患者为 aPS/PT IgM 阳性（6/8 LA 阳性）。一名患者的 aPS/PT IgG 和 IgM 均呈阳性。 LA阳性患者仅有高滴度aPS/PT IgG/IgM，均≥80 U/ml，而2例LA阴性患者aPS/PT IgM阳性，滴度中等[40-60 U/ml] 。考虑到所有 TGA 参数，与 LA 阴性患者相比，LA 阳性患者的 TGA 谱显着改变。 LA 阳性患者的 tLag 显着较高（8.4 ± 3.3 分钟 vs. 6.6 ± 1.8 分钟； p = 0.046），较高的 tPeak（14 ± 4.3 分钟 vs. 11 ± 2.7 分钟； p = 0.015）和较低的峰值（207 ± 152） nM 与 356.3 ± 104.7 nM； p < 0.001）和较低的 AUC（2109.7 ± 1006.9 nM 与 2772.5 ± 776.8 nM； p = 0.033）。 TGA 测试也证实，aPS/PT 的使用可能有助于识别 CVE 和 APS 患者。