Anticardiolipin antibodies (ACA) directed not to cardiolipin but to a plasma protein cofactor

doi:10.1016/0140-6736(90)91374-J

The Lancet

Volume 335, Issue 8705, 30 June 1990, Pages 1544-1547

https://doi.org/10.1016/0140-6736(90)91374-J Get rights and content

Abstract

The binding of affinity-purified anticardiolipin antibodies (ACA) to liposomes that contained cardiolipin or phosphatidylserine was investigated. ACA bound to these liposomes only in the presence of plasma or serum, which indicated a requirement for a plasma component. This component—referred to as aca-cofactor—was purified; its activity to support ACA binding to liposomes that contained cardiolipin was not destroyed by heat (10 min at 90°C), but was greatly diminished on incubation with trypsin. aca-cofactor bound liposomes that contained negatively charged phospholipid but had no affinity for liposomes that contained neutral phospholipid (eg, phosphatidylcholine); this binding was independent of calcium ions. aca-cofactor was essential for ACA to bind to liposomes that contained cardiolipin or phosphatidylserine and, when coated on a microtitre plate in the absence of any phospholipid, aca-cofactor was an apparent antigen for ACA in an enzyme-linked immunosorbent assay. aca-cofactor is a single chain polypeptide with an apparent molecular weight of 50 kD (non-reduced), which increases to 70 kD upon reduction, and its properties closely resemble those of β₂-glycoprotein I (apolipoprotein H).

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MEDICAL SCIENCEAnticardiolipin antibodies (ACA) directed not to cardiolipin but to a plasma protein cofactor

Abstract

Lancet

Blood

Anal Biochem

Biochim Biophys Acta

Lupus anticoagulants and thrombosis

Measurement of anti-cardiolipin antibodies by an enzyme-linked immunosorbent assay: standardization and quantitation of results

Clin Exp Immunol

$MEDICAL SCIENCE$
Anticardiolipin antibodies (ACA) directed not to cardiolipin but to a plasma protein cofactor