Effect of IVIG in antibody-mediated thrombocytopenia after continuous infusion of antiplatelet mAb.

(A) Effect on platelet counts by continuous infusion of antiplatelet mAb MWReg30 by an implanted osmotic pump in wild-type (■), FcγRIII^−/− (▪), and FcR γ-chain^−/−(▴) mice. Time course of mean platelet counts of 3 experiments (± SEM) is shown except for the wild-type mice (n = 2). Asterisks indicate statistically significant differences compared to saline control (*P < .05; **P < .01). B) Effect on platelet counts after intravenous injection of aged IVIG (▪) or monomeric IgG (▴) at t = 4 days. Aged IVIG preparations used in the experiment was stored at 4°C for 1 year. Results are expressed as mean of 5 experiments ± SEM on different occasions. Asterisks indicate statistically significant differences between the 2 groups (**P < .01; ***P < .001).