Antibody specificity in patient 5 for the GPIb/IX/V complex.

Specificity of the antibody in patient 5 for the GPIb/IX/V complex was demonstrated by MACE. Values shown are the differences of optical density values obtained in the presence and absence of drug. Positive reactions were obtained with mAb MBC 142.11 specific for the GPIb/IX complex, but not with AP2 (anti-GPIIb/IIIa), MBC131.4 (anti-GPIV), or AP1 specific for the glycocalicin domain of GPIb. ▤, normal serum; ▨, patient 5. Brackets indicate mean ± 1 SD of a study done in triplicate.