Solid Phase Immunoassay for the Detection of Anticardiolipin Antibodies

The anticardiolipin (aCL) test was first developed in the 1980s and proved to be a valuable addition to the lupus anticoagulant assay for identifying patients with a disorder that came to be later known as the antiphospholipid syndrome (APS). Although the test has relatively poor specificity for APS diagnosis, particularly at low positive levels, it has continued to play a major role in the identification and management of these patients because of its high sensitivity and ability to be measured in both serum and plasma, and despite concomitant presence of anticoagulants normally given to APS patients. In this chapter we outline the procedure for producing essential assay components and for performing the aCL ELISA, which can be used to determine the presence of IgG, IgM and IgA aCL antibodies in human samples. We also provide general guidelines that will facilitate optimal performance of the aCL ELISA assay.