title: Antiphospholipid antibodies require beta 2-glycoprotein I (apolipoprotein H) as cofactor.
abstract: IgG was isolated from 9 patients with high levels of anticardiolipin antibodies (aCL). The standard ELISA was modified, using gelatin to postcoat ELISA plates and as diluent. Under these conditions, 8/9 samples of IgG bound to cardiolipin only in the presence of a cofactor, found in fetal calf serum and normal human serum (NHS). beta 2-glycoprotein I (apolipoprotein H) was at least as effective as NHS as a cofactor for 7/9 IgG samples. Our studies confirm that for some aCL detected in conventional assays, the antibody will react with cardiolipin only if beta 2-glycoprotein I is present.
authors.affiliation: Department of Medicine, Dalhousie University, Halifax, NS, Canada.
authors.forename: J V
authors.initials: JV
authors.lastname: Jones
authors.forename: H
authors.initials: H
authors.lastname: James
authors.forename: M H
authors.initials: MH
authors.lastname: Tan
authors.forename: M
authors.initials: M
authors.lastname: Mansour
mesh_terms: D017152:Antibodies, Antiphospholipid / Q000502:physiology*; D002308:Cardiolipins / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000502:physiology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000378:metabolism; D053482:beta 2-Glycoprotein I
chemical_list: D017152:Antibodies, Antiphospholipid; D002308:Cardiolipins; D006023:Glycoproteins; D007074:Immunoglobulin G; D053482:beta 2-Glycoprotein I