Division of Rheumatology, Department of Medicine Solna, Karolinska Institutet, Karolinska University Hospital, Stockholm.
Division of Clinical Epidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm.
Rheumatology (Oxford). 2020 Nov 1;59(11):3264-3274. doi: 10.1093/rheumatology/keaa092.
Complement components, including C4d, can be found on activated platelets, a process associated with vascular disease in SLE. We investigated whether platelet C4d (PC4d) adds additional value to traditional and known lupus-associated risk factors when identifying SLE patients with vascular disease.
This cross-sectional study included 308 well-characterized SLE patients and 308 matched general population controls. PC4d deposition was analysed using flow cytometry. Values >95% of controls were considered as PC4d positive (+). aPL were determined by Luminex, and the LA test was performed by DRVVT. History of vascular disease (composite and as separate outcomes) was defined at inclusion.
SLE patients had increased PC4d deposition as compared with population controls (50 vs 5%, P < 0.0001). PC4d+ positively associated with any vascular events, and separately with venous and cerebrovascular events, and also with all investigated aPL profiles. The association for any vascular event remained statistically significant after adjustment for traditional and SLE-associated risk factors (odds ratio: 2.3, 95% CI: 1.3, 4.3, P = 0.008). Compared with patients negative for both PC4d and LA, patients with double positivity were more likely to have vascular disease (odds ratio: 12.3, 95% CI: 5.4, 29.3; attributable proportion due to interaction 0.8, 95% CI: 0.4, 1.1).
PC4d+ is associated with vascular events in SLE, independently of traditional and SLE-associated risk factors. Concurrent presence of PC4d and LA seem to interact to further increase the odds for vascular events. Prospective studies should examine whether the aPL/PC4d combination can improve prediction of vascular events in SLE and/or APS.
补体成分，包括 C4d，可在激活的血小板上找到，这一过程与 SLE 中的血管疾病有关。我们研究了当识别患有血管疾病的 SLE 患者时，血小板 C4d（PC4d）是否在传统的和已知的狼疮相关危险因素之外提供额外的价值。
这项横断面研究纳入了 308 名特征明确的 SLE 患者和 308 名匹配的一般人群对照。使用流式细胞术分析 PC4d 沉积。将>95%的对照值视为 PC4d 阳性（+）。通过 Luminex 测定抗磷脂抗体（aPL），并通过 DRVVT 进行狼疮抗凝物（LA）试验。血管疾病史（综合和单独的结局）在纳入时定义。
与人群对照相比，SLE 患者的 PC4d 沉积增加（50%比 5%，P<0.0001）。PC4d+与任何血管事件呈正相关，分别与静脉和脑血管事件呈正相关，也与所有调查的 aPL 谱呈正相关。在调整传统和 SLE 相关危险因素后，任何血管事件的关联仍然具有统计学意义（比值比：2.3，95%置信区间：1.3，4.3，P=0.008）。与 PC4d 和 LA 均阴性的患者相比，双阳性患者发生血管疾病的可能性更大（比值比：12.3，95%置信区间：5.4，29.3；交互归因比例 0.8，95%置信区间：0.4，1.1）。
PC4d+与 SLE 中的血管事件相关，独立于传统的和 SLE 相关的危险因素。PC4d 和 LA 的同时存在似乎相互作用，进一步增加了血管事件的几率。前瞻性研究应探讨 aPL/PC4d 联合是否能改善 SLE 和/或 APS 中血管事件的预测。
