The evolution, evaluation and interpretation of antiphospholipid antibody assays
Abstract aPA have been observed in a variety of clinical settings, many of which are associated with thrombotic events in the venous, arterial or placental circulation. Although many assays have evolved to detect aPA the most sensitive ones are those that use the following: 1) bovine serum as a blocking and/or diluting supplement, 2) multiple phospholipid antigens (CL, PS and PE), and 3) conjugates to detect several antibody isotypes (IgG, IgA and IgM). The reported variation in aPA detection is significant; therefore, it is important to test a large number of healthy individuals with the aPA ELISA to determine which patient ELISA values are above normal compared to the local population. Inasmuch as individual assays vary this will ensure that an elevated aPA value in one lab is comparable to an elevated aPA value in another laboratory. As laboratories continue to standardize individual assays both internally and externally, concurrence among laboratories should increase.