6B4, but not AK2, induces shear-dependent platelet signaling and IVIg-resistant platelet clearance in mice. (A) Graphs of percentage of positive events for Erythrina cristagalli lectin, Lact-C2, and P-selectin exposure in human (top) and hTg (bottom) PRP treated with control IgG, AK2, or 6B4. Samples were exposed to 0, 5, or 30 dyn/cm2 as indicated (n = 5). (B) Platelet survival curves for hTg mice injected retro-orbitally with AK2 or 6B4 24 hours after intraperitoneal IVIg treatment. Blood was drawn from mice at the time of IVIg administration (–24 hours), time of antibody injection (0 hours), and thereafter every 24 hours until 96 hours after antibody injection. Platelet count determined by complete blood count analysis. *P ≤ .05, **P ≤ .01, ***P ≤ .001. HSA, human serum albumin.
