Effect of β2GPI on coagulation. The effects of circular and open β2GPI on the aPTT were determined. Circular and open β2GPI was added to normal pool plasma (NPP). (A) Control indicates NPP; circular, NPP with addition of 15 μg/mL plasma β2GPI; circular to open, NPP to which 15 μg/mL plasma β2GPI treated at pH 11.5 was added; and circular to open to circular, NPP to which 15 μg/mL plasma β2GPI first incubated at pH 11.5 and subsequently treated at pH 3.5 was added. (B) Control indicates NPP; anti-β2GPI, NPP to which 15 μg/mL purified monoclonal anti-β2GPI antibody was added; anti-β2GPI + circular β2GPI, NPP with addition of preincubated (5 minutes) anti-β2GPI antibody and plasma β2GPI; and anti-β2GPI + open β2GPI, NPP with addition of preincubated (5 minutes) anti-β2GPI antibody and plasma β2GPI first incubated at pH 11.5 and subsequently treated at pH 3.5 (both 15 μg/mL). Bars represent mean ± SD (n = 3).
