Laboratory Evaluation of Antiphospholipid Syndrome

Am J Clin Pathol. 2019 Oct 7;152(5):638-646. doi: 10.1093/ajcp/aqz085.


Objectives: Anti-β2 glycoprotein I domain I (anti-domain I) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies are present in patients with antiphospholipid syndrome (APS); however, their use in evaluation remains unclear.

Methods: Diagnostic attributes of lupus anticoagulant (LAC), anti-domain I IgG, anti-cardiolipin, anti-β2 glycoprotein I (anti-β2GPI), and aPS/PT IgG and IgM antibodies were assessed in 216 patients evaluated for APS.

Results: LAC had the best odds ratio (OR, 14.2) while that for anti-domain 1 IgG was comparable to anti-β2GPI IgG (OR, 8.3 vs 9.4) but higher than all others. Significant correlations were observed for thrombosis (P = .03) and pregnancy-related morbidity (P = .001) with anti-domain IgG and for any thrombosis with aPS/PT IgG (P = .006). Use of noncriteria antiphospholipid with or without criteria markers did not significantly increase the probability to diagnose APS.

Conclusions: Noncriteria tests can contribute to diagnosis and stratification of APS but do not improve diagnostic yield. Optimal strategies for implementation require prospective investigation.

Keywords: Antiphospholipid antibodies; Antiphospholipid syndrome; Diagnostic significance.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Antiphospholipid / blood*
  • Antiphospholipid Syndrome / classification
  • Antiphospholipid Syndrome / diagnosis*
  • Antiphospholipid Syndrome / immunology
  • Autoantibodies / blood*
  • Cardiolipins / immunology
  • Female
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Lupus Coagulation Inhibitor / blood
  • Male
  • Middle Aged
  • Odds Ratio
  • Phosphatidylserines / immunology
  • Pregnancy
  • Pregnancy Complications / immunology
  • Prothrombin / immunology
  • Retrospective Studies
  • beta 2-Glycoprotein I / immunology


  • Antibodies, Antiphospholipid
  • Autoantibodies
  • Cardiolipins
  • Immunoglobulin G
  • Immunoglobulin M
  • Lupus Coagulation Inhibitor
  • Phosphatidylserines
  • beta 2-Glycoprotein I
  • Prothrombin