Renal protective effect of antiplatelet therapy in antiphospholipid antibody-positive lupus nephritis patients without antiphospholipid syndrome

Objective
We sought to evaluate the effect of antiplatelet therapy in addition to conventional immunosuppressive therapy for lupus nephritis (LN) patients positive for antiphospholipid antibodies (aPL) without definite antiphospholipid syndrome (APS).
Methods
Patients with biopsy-proven LN class III or IV were retrospectively evaluated. We selected patients positive for anticardiolipin antibody (aCL) or lupus anticoagulant (LA) who did not meet the criteria for a diagnosis of APS. The patients were divided into two subgroups according to whether antiplatelet therapy was received. The cumulative complete renal response (CR) rate, relapse-free rate, and change in estimated glomerular filtration rate (eGFR) over 3 years after induction therapy were calculated.
Results
We identified 17 patients who received antiplatelet therapy and 21 who did not. Baseline clinicopathological characteristics and immunosuppressive therapy did not show a significant difference between the two groups except for a higher incidence of LN class IV in the treatment group (p = 0.03). There was no difference in cumulative CR rate, relapse-free rate, or eGFR change between these subgroups. However, when data on LA-positive patients were assessed, an improvement in eGFR was found (p = 0.04) in patients receiving antiplatelet treatment.
Conclusion
Addition of anti-platelet therapy was associated with an improvement of eGFR in LA-positive patients with LN class III or IV.

研究目标
本研究旨在评估对于抗磷脂抗体（antiphospholipid antibodies, aPL）阳性但未确诊抗磷脂综合征（antiphospholipid syndrome, APS）的狼疮肾炎（lupus nephritis, LN）患者，在常规免疫抑制治疗基础上加用抗血小板治疗的疗效。

研究方法
本研究对活检证实为Ⅲ型或Ⅳ型狼疮肾炎的患者进行回顾性分析。纳入抗心磷脂抗体（anticardiolipin antibody, aCL）或狼疮抗凝物（lupus anticoagulant, LA）阳性，但不符合抗磷脂综合征诊断标准的患者。根据是否接受抗血小板治疗将患者分为两个亚组。计算诱导治疗后3年内的累积完全肾脏应答（complete renal response, CR）率、无复发生存率及估算肾小球滤过率（estimated glomerular filtration rate, eGFR）变化值。

研究结果
本研究共纳入接受抗血小板治疗的患者17例，未接受抗血小板治疗的患者21例。两组患者的基线临床病理特征及免疫抑制治疗方案均无显著差异，仅治疗组的Ⅳ型狼疮肾炎发生率更高（p=0.03）。两个亚组的累积完全肾脏应答率、无复发生存率及估算肾小球滤过率变化值均无显著差异。但针对狼疮抗凝物阳性患者的亚组分析显示，接受抗血小板治疗的患者估算肾小球滤过率得到改善（p=0.04）。

研究结论
对于Ⅲ型或Ⅳ型狼疮肾炎且狼疮抗凝物阳性的患者，在常规治疗基础上加用抗血小板治疗可改善其估算肾小球滤过率。