Keeling D M, Wilson A J, Mackie I J, Machin S J, Isenberg D A
Department of Haematology, University College and Middlesex School of Medicine, London.
Br J Haematol. 1992 Nov;82(3):571-4. doi: 10.1111/j.1365-2141.1992.tb06469.x.
Some antiphospholipid antibodies (aPL) only bind to anionic phospholipids in the presence of a serum cofactor, beta 2-glycoprotein I (beta 2GPI). Whether these aPL can bind to beta 2GPI in the absence of phospholipid is controversial. We have purified anticardiolipin antibodies (aCL) from the plasma of four patients and beta 2GPI from normal plasma by solid phase affinity methods. All four aCL bound to cardiolipin and phosphatidylserine in the presence of beta 2GPI but not in its absence. The binding of two of the antibodies to cardiolipin and phosphatidylserine at various concentrations of human beta 2GPI was compared with that obtained using 10% bovine serum. The two antibodies responded differently to increasing beta 2GPI concentrations, and binding to phosphatidylserine was relatively greater than to cardiolipin using human beta 2GPI. All four aCL bound to plastic plates coated with beta 2GPI in the absence of phospholipid, and beta 2GPI in the fluid phase had no effect on binding. Binding to beta 2GPI coated plates was increased equally when bovine serum or bovine albumin were used as the sample diluent in place of gelatine. These findings and those of others have important implications for the design of assays for antiphospholipid antibodies.
一些抗磷脂抗体（aPL）仅在血清辅因子β2糖蛋白I（β2GPI）存在的情况下与阴离子磷脂结合。这些aPL在没有磷脂的情况下是否能与β2GPI结合仍存在争议。我们通过固相亲和方法从4例患者的血浆中纯化了抗心磷脂抗体（aCL），并从正常血浆中纯化了β2GPI。所有4种aCL在β2GPI存在时能与心磷脂和磷脂酰丝氨酸结合，但在其不存在时则不能。将其中两种抗体在不同浓度的人β2GPI存在下与心磷脂和磷脂酰丝氨酸的结合情况与使用10%牛血清时的情况进行了比较。这两种抗体对β2GPI浓度增加的反应不同，使用人β2GPI时与磷脂酰丝氨酸的结合相对大于与心磷脂的结合。所有4种aCL在没有磷脂的情况下能与包被有β2GPI的塑料板结合，液相中的β2GPI对结合没有影响。当使用牛血清或牛白蛋白代替明胶作为样品稀释剂时，与包被有β2GPI的板的结合同样增加。这些发现以及其他研究结果对抗磷脂抗体检测方法的设计具有重要意义。
