Association of autoantibodies against the phosphatidylserine-prothrombin complex with manifestations of the antiphospholipid syndrome and with the presence of lupus anticoagulant

Arthritis Rheum. 2000 Sep;43(9):1982-93. doi: 10.1002/1529-0131(200009)43:9<1982::AID-ANR9>3.0.CO;2-2.


Objective: To clarify the association of autoantibodies against prothrombin with the clinical manifestations of the antiphospholipid syndrome (APS) and with the presence of lupus anticoagulant (LAC).

Methods: We examined 265 patients who visited our autoimmune disease clinic. IgG and IgM antiprothrombin antibodies were tested by enzyme-linked immunosorbent assay (ELISA) as either antiphosphatidylserine-prothrombin complex (aPS/PT) antibodies or as antibodies against prothrombin coated on irradiated ELISA plates (as antigen) (aPT). IgG, IgM, and IgA anticardiolipin (aCL) antibodies and their beta2-glycoprotein I (beta2GPI) dependency were also evaluated by ELISA. LAC was tested by 3 different methods.

Results: The presence of aPS/PT, but not of aPT, significantly correlated with the clinical manifestations of APS (odds ratio [OR] 4.39, 95% confidence interval [95% CI] 2.06-9.38), and aPS/PT antibodies were as specific as beta2GPI-dependent aCL for APS (93.1% for both). IgG aPS/PT strongly correlated with the presence of LAC as detected using the dilute Russell viper venom time test (OR 38.2, 95% CI 13.4-109.1).

Conclusion: Antiprothrombin antibodies are heterogeneous and their clinical relevance depends on the method of detection applied. Positive results on the aPS/PT test can serve as a marker of thrombotic events in patients with autoimmune diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Aged
  • Aged, 80 and over
  • Antibodies, Anticardiolipin / blood
  • Anticoagulants / blood
  • Antiphospholipid Syndrome / blood
  • Antiphospholipid Syndrome / immunology*
  • Autoantibodies / blood
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Glycoproteins / blood
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Lupus Coagulation Inhibitor / blood*
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Phosphatidylserines / immunology*
  • Prothrombin / immunology*
  • beta 2-Glycoprotein I


  • Antibodies, Anticardiolipin
  • Anticoagulants
  • Autoantibodies
  • Glycoproteins
  • Immunoglobulin G
  • Immunoglobulin M
  • Lupus Coagulation Inhibitor
  • Phosphatidylserines
  • beta 2-Glycoprotein I
  • Prothrombin