IVIG does not directly bind 7E3.

7E3 (▪) (or control IgG, ■) and IVIG were combined in vitro, at a constant IVIG concentration (25 mg/mL) and varying 7E3 concentrations (0-0.1 mg/mL). The positive control was a mouse antihuman IgG. Samples were then added to a microplate coated with antihuman IgG. Murine IgG binding was visualized using a secondary antimouse IgG–alkaline phosphatase conjugate. p-Nitrophenyl phosphate was added, and the plates were read at 405 nm (kinetic assay, over 10 minutes). Assay response to 7E3 did not differ from control (P = .164), whereas the positive control differed significantly from control (P < .001).