Schematic representation of the MAIPA assay.

The MAIPA assay is an antigen-capture ELISA that uses a mAb to capture GPIb-IX complex to which the human drug-dependent antibody has already bound at a site distant from the mAb-binding site (A). If the human antibody and the murine mAb-binding sites coincide or are in close proximity to each other, the human antibody cross-blocks the mAb, the antigen/drug-dependent antibody complex is not captured by the anti-mouse IgG antibody, and a negative result is obtained (B).