Confirmation of initial antiphospholipid antibody positivity depends on the antiphospholipid antibody profile

J Thromb Haemost. 2013 Aug;11(8):1527-31. doi: 10.1111/jth.12264.


Background: The revised classification criteria for the antiphospholipid syndrome state that antiphospholipid (aPL) antibodies (lupus anticoagulant [LAC] and/or anticardiolipin [aCL] and/or anti-β2 -glycoprotein I [aβ2 GPI] antibodies) should be detected on two or more occasions at least 12 weeks apart. Consequently, classification of patient risk and adequacy of treatment may be deferred by 3 months.

Objectives: In order to early classify patient risk, we evaluated whether aPL positivity confirmation is related to aPL antibody profiles.

Patients and methods: Consecutive patients referred to our center who were initially positive in one or more tests exploring the presence of aPL were tested after 3 months. During a 4-year period, 225 patients were initially positive in one or more tests, and 161 were available for confirmation after 3 months. Patients were classified as triple-positive (n = 54: LAC(+) , aCL(+) , aβ2 GPI(+) , same isotype), double-positive (n = 50: LAC(-) , aCL(+) , aβ2 GPI(+) , same isotype) and single-positive (n = 53: LAC or aCL or aβ2 GPI antibodies as the sole positive test).

Results: Among subjects with triple positivity at initial testing, 98% (53 of 54) had their aPL profile confirmed after 12 weeks. The double-positive and single-positive groups had data confirmed in 42 of 50 (84%) and 23 of 57 (40%) subjects, respectively.

Conclusions: Our results show that high-risk subjects with triple-positive aPL profiles are identified early, at the time of the initial screening tests.

Keywords: cardiolipin; glycoprotein I; lupus anticoagulant; phospholipid; thrombosis; β2.

MeSH terms

  • Adult
  • Antibodies, Anticardiolipin / immunology
  • Antibodies, Antiphospholipid / blood*
  • Antibodies, Antiphospholipid / immunology
  • Antiphospholipid Syndrome / blood
  • Antiphospholipid Syndrome / diagnosis*
  • Antiphospholipid Syndrome / immunology
  • Cohort Studies
  • Female
  • Humans
  • Lupus Coagulation Inhibitor / blood*
  • Lupus Coagulation Inhibitor / immunology
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Reproducibility of Results
  • Risk
  • Thrombosis / blood*
  • Time Factors
  • beta 2-Glycoprotein I / chemistry*


  • Antibodies, Anticardiolipin
  • Antibodies, Antiphospholipid
  • Lupus Coagulation Inhibitor
  • beta 2-Glycoprotein I