Liposomes entrapping the dye sulforhodamine B were used to develop an
assay for anticardiolipin antibodies (ACAs), In the presence of magnes
ium ions, IgG ACAs induced liposomal lysis and the resulting absorbanc
e changes were dependent on the amount of ACAs present, The liposomal
assay (y) showed similar intraassay imprecision and detection limit to
an ELISA for IgG ACAs (x), with a correlation coefficient of 0.90 (y
= 1.05x - 1.61). no correlation with ELISA IgM ACA measurements was ob
served, Although ELISA remains the method of choice, particularly in e
xamining different ACA classes, the liposomal assay offers advantages
of speed and potential for processing large numbers of samples for IgG
ACAs. This may facilitate study of the significance of increased IgG
ACAs in the groups of conditions with which they are associated, and p
erhaps enable more laboratories to perform the test.