β2‐GPI‐dependent and independent binding of anticardiolipin antibodies in patients with recurrent spontaneous abortions

Abstract
We measured anticardiolipin antibodies (aCL) in plasma samples from 214 women with a history of recurrent spontaneous abortions by an enzyme-linked immunosorbent assay (ELISA) utilizing solid phase cardiolipin (CL) and β2-glycoprotein I (β2-GPI). Sixteen patients (7.5%) were positive for β2-GPI-dependent aCL. Though β2-GPI appeared to enhance the binding of aCL, β2-GPI-independent aCL were also observed in these patients (4.7%). The patients were classified into three groups on the basis of their medical history, and analysis of data of individual groups revealed that the incidence of β2-GPI-dependent aCL was significantly higher in patients who had experienced at least one fetal loss in the second or third trimester.