Elution of anticardiolipin antibodies and their cofactor beta 2-glycoprotein 1 from the placentae of patients with a poor obstetric history.

Anticardiolipin antibodies (aCL) were eluted from the placentae of four women with elevated serum levels of aCL, demonstrating that these antibodies are bound to affected placentae. Anticardiolipin antibodies bound to affected placentae were only of the IgG isotype and the level of aCL in placental eluates did not reflect serum levels. Anticardiolipin antibodies were not isolated from placental eluates of control normal pregnancies. beta 2-Glycoprotein 1, the anticardiolipin antibody cofactor, was present in the placental eluates from both control and antiphospholipid antibody (aPL) affected pregnancies and was localised in the syncytiotrophoblast by immunohistochemical analysis. Antinuclear antibodies were present in the placental eluates of 3 of the 4 patients with antiphospholipid antibody syndrome and were absent from the placental eluates of control pregnancies. The authors propose that anticardiolipin antibody binds directly to placental tissue, disrupting uteroplacental blood flow and/or transport through the villi.