Reactivity and binding of serum autoantibodies to GPIIb-IIIa.

(A) Reactivity of serum autoantibodies from patients 3 and 8 with KO variant GPIIb-IIIa. (B) Effects of 10 μg/mL nonlabeled OP-G2 on the binding of the serum autoantibodies to WT GPIIb-IIIa. Serum antibodies from patients 3 and 8, whose PA autoantibodies showed the impaired binding to KO variant GPIIb-IIIa, were affinity purified using platelets. Open columns represent ΔOD value in antigen-capture ELISA using WT GPIIb-IIIa. Solid columns represent ΔOD value in antigen-capture ELISA using KO variant GPIIb-IIIa. Hatched columns are ΔOD value in antigen-capture ELISA using WT GPIIb-IIIa in the presence of 10 μg/mL nonlabeled OP-G2.