Development of immunoassays for anti-electronegative LDL autoantibodies and immune complexes.

Background: Electronegative low-density lipoprotein (LDL-) promotes atherosclerosis through inflammatory and immunologic mechanisms that lead to the production of anti-LDL(-) autoantibodies and to the subsequent formation of immune complexes (IC) and macrophage foam cells. We described the development and validation of an ELISA for the quantification of free anti-LDL(-) autoantibodies and an ELISA for the quantification of IC consisting of LDL(-)-bound IgG in human plasma.

Methods: LDL(-) purified from human plasma, and anti-LDL(-) monoclonal antibody Fab fragments were adsorbed onto ELISA plates to capture anti-LDL(-) autoantibodies and IC-LDL(-), respectively.