Figure 1.
Anti–β2-GPI mAbs inhibit APC anticoagulant activity in a phospholipid oxidation–dependent manner. Plasma clotting was initiated with X-CP as described in “Materials and methods,” in the presence (□, ○) or absence (▪, •) of 0.2 μg/mL APC. Monoclonal IgG was incorporated in the clotting assays at the final concentrations indicated. Nonoxidized phospholipid (○, •); oxidized phospholipid (□, ▪). “Control” indicates addition of an irrelevant mAb IgG at the concentrations indicated. The normal range of the clotting time of pooled normal plasma using unoxidized PE-containing liposomes was 28.9±1.1 seconds SD (n = 15) in the absence of APC and 64.2±2.4 seconds (n = 9) in the presence of APC. The data represent 3 experiments run in duplicate.
