Reactivity of patients' anti-FIX IgGs against chimeras FX/FIX-AP-Prot, FX/FIX-AP, and FX/FIX-Gla-EGF1-EGF2.

To distinguish the reactivity of patients' IgGs toward the domains of FIX, medium from cells expressing chimeras FX/FIX-Gla-EGF1-EGF2, FX/FIX-AP-Prot, and FX/FIX-AP was added to microtiter plates coated with polyclonal anti-FX antibody. The response of patients' anti-FIX IgG against the chimeras was investigated in the presence of Ca⁺⁺ and EDTA as described in “Patients, materials, and methods.” Data represent the mean values from 3 to 6 experiments (± SD).