What is the advantage of an assay for anti-phospholipid antibody cofactors over an assay for the antibody itself?

Binding of b2GPI to the microwell surface in an ELISA assay may produce a neoepitope similar to that when combined with a phospholipid; assay results with this system show a good correlation with the APS. The serologic detection of anti-b2GPI antibodies provides enhanced clinical sensitivity for thrombosis.