Effect of patients' anti-FIX IgGs on FVIIIa-dependent FX activation by FIXa.

The ability of various concentrations of patient1 (▵), patient 2 (●), patient 3 (▴), patient 4 (▪), and healthy control (○) IgGs to inhibit the FVIIIa-dependent activation of FX was investigated in vitro (see “Patients, materials, and methods”). Data represent the mean values from 4 experiments.