title: Association of anti-beta 2 glycoprotein I antibodies with lupus-type circulating anticoagulant and thrombosis in systemic lupus erythematosus.
abstract: OBJECTIVE
  Antiphospholipid antibodies (including anticardiolipin antibodies and circulating anticoagulant) are associated with thrombosis in systemic lupus erythematosus. Since it has been shown that beta 2 glycoprotein I (beta 2 gp I) acts as a cofactor of anticardiolipin antibody binding to cardiolipin, the presence and clinical meaning of anti-beta 2gp I antibodies in sera from patients with lupus were examined.
  
  
  METHODS
  An enzyme-linked immunosorbent assay technique for the detection of anti-beta 2gp I antibodies was developed, and 47 lupus sera were studied retrospectively, as well as 88 healthy blood donors' sera.
  
  
  RESULTS
  It was found that 17 of 47 patients with lupus (36%) had anti-beta 2gp I antibodies. Anti-beta 2gp I antibodies were statistically associated with anticardiolipin antibodies, thrombosis, and lupus anticoagulant. Eight of nine lupus patients with thrombosis had anti-beta 2gp I antibodies and lupus anticoagulant, and seven of them had anticardiolipin antibodies. Of 18 patients with anticardiolipin antibodies without anti-beta 2gp I antibodies or lupus anticoagulant, only one had thrombosis (due to nephrotic syndrome). Among anti-beta 2gp I-positive patients, 14 of 16 had lupus anticoagulant activity, whereas only three patients with lupus anticoagulant were anti-beta 2gp I-negative.
  
  
  CONCLUSIONS
  The presence of anti-beta 2gp I antibodies is a new immunologic feature of lupus patients with thrombosis. In addition, since anti-beta 2gp I antibodies are closely associated with lupus anticoagulant activity, they may contribute to explain antiprothrombinase activity.
authors.affiliation: Service d'Immunologie Clinique-INSERM U25, Hôpital Necker, Paris, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Viard
authors.forename: Z
authors.initials: Z
authors.lastname: Amoura
authors.forename: J F
authors.initials: JF
authors.lastname: Bach
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D001779:Blood Coagulation Factors / Q000378:metabolism; D002308:Cardiolipins / Q000276:immunology; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000201:enzymology / Q000276:immunology*; D012189:Retrospective Studies; D013927:Thrombosis / Q000209:etiology / Q000276:immunology*; D053482:beta 2-Glycoprotein I
chemical_list: D001323:Autoantibodies; D001779:Blood Coagulation Factors; D002308:Cardiolipins; D006023:Glycoproteins; D016682:Lupus Coagulation Inhibitor; C028128:antiprothrombinase; D053482:beta 2-Glycoprotein I