FACTORS AFFECTING CARDIOLIPIN ANTIBODY-ASSAYS - MODIFICATION WITH POLYETHYLENE-GLYCOL COMPOUND

Anti-cardiolipin antibody (aCL) measurement is only semi-reproducible, and current assays detect irrelevant as well as clinically significan t antibodies. Factors found to influence results included the source o f enzyme-linked immunoabsorbent assay (ELISA) plate, and its pretreatm ent with solvents; the nature of the blocking solution; and the compos ition of the diluent used for reagents. Fetal calf serum (FCS) in the diluent appeared to reduce non-specific (clinically irrelevant) bindin g and was not simply a source of beta(2)-glycoprotein-1 (beta(2)-GP1). A polyethylene glycol compound was found to be an effective blocking agent, and its use enhanced the discrimination between positive and ne gative samples. A high level of variation may be inherent in a aCL-ELI SA methodology, but the use of polyethylene glycol compound appeared t o be a helpful modification.