Pierangeli S S, Harris E N, Gharavi A E, Goldsmith G, Branch D W, Dean W L
Department of Medicine, University of Louisville, Kentucky 40292.
Br J Haematol. 1993 Sep;85(1):124-32. doi: 10.1111/j.1365-2141.1993.tb08655.x.
Recent studies have suggested that the lupus anticoagulant (LA) may be specific for prothrombin, prothrombin-phospholipid complexes, or beta 2 glycoprotein 1 (beta 2GP1) rather than phospholipids. We performed a series of experiments to determine whether LA is indeed phospholipid specific. IgG was purified from sera of six patients with the antiphospholipid syndrome (APS) and 10 healthy controls. The six IgG-APS preparations had both LA and anticardiolipin (aCL) activity. Incubation of the six IgG-APS preparations with cardiolipin (CL), phosphatidylserine (PS), phosphatidylcholine (PC), or PS/PC (20:80) liposomes in Tris-buffered saline, resulted in loss of LA activity from the supernatant. We postulated that loss of activity might have resulted from absorption of IgG LA antibodies by phospholipids, a dilutional effect, or the presence of phospholipids in the supernatant causing 'by-pass' of IgG LA inhibitory activity. To distinguish between these possibilities, we re-isolated IgG from the supernatants and re-tested them for LA activity. IgG re-isolated from the PS. CL and PS/PC supernatants had no LA activity, but LA activity remained in the PC supernatant. This suggested that IgG with LA activity was absorbed by negatively charged but not by zwitterionic phospholipids. In like manner, PS, CL and PS/PC, but not PC liposomes, absorbed IgG with aCL activity. Mixtures of the phospholipid liposomes with beta 2GP1 did not modify the absorption of IgG with LA or aCL activity. Finally, we demonstrated that IgG eluted from immunoglobulin-cardiolipin liposome complexes had LA activity. Based on these findings, we conclude that at least one population of antibodies with LA activity is phospholipid specific.
最近的研究表明，狼疮抗凝物（LA）可能对凝血酶原、凝血酶原 - 磷脂复合物或β2糖蛋白1（β2GP1）具有特异性，而不是对磷脂具有特异性。我们进行了一系列实验以确定LA是否确实对磷脂具有特异性。从6例抗磷脂综合征（APS）患者和10例健康对照者的血清中纯化IgG。这6种IgG - APS制剂均具有LA和抗心磷脂（aCL）活性。在Tris缓冲盐溶液中，将这6种IgG - APS制剂与心磷脂（CL）、磷脂酰丝氨酸（PS）、磷脂酰胆碱（PC）或PS/PC（20:80）脂质体一起孵育，导致上清液中LA活性丧失。我们推测活性丧失可能是由于磷脂吸收了IgG LA抗体、稀释作用或上清液中存在磷脂导致IgG LA抑制活性“旁路”所致。为了区分这些可能性，我们从上清液中重新分离出IgG并重新检测其LA活性。从PS、CL和PS/PC上清液中重新分离出的IgG没有LA活性，但PC上清液中仍保留LA活性。这表明具有LA活性的IgG被带负电荷的磷脂吸收，而不是被两性离子磷脂吸收。同样，PS、CL和PS/PC脂质体，但不是PC脂质体，吸收了具有aCL活性的IgG。磷脂脂质体与β2GP1的混合物并未改变具有LA或aCL活性的IgG的吸收。最后，我们证明从免疫球蛋白 - 心磷脂脂质体复合物中洗脱的IgG具有LA活性。基于这些发现，我们得出结论，至少有一群具有LA活性的抗体对磷脂具有特异性。
