title: Triple positive antiphospholipid antibody profile in outpatients with tests for lupus anticoagulants.
abstract: BACKGROUND
  A triple positive antiphospholipid (aPL) antibody profile [two positive serum IgG aPL antibodies along with one positive functional plasma lupus anticoagulant (LAC) test result] is associated with an increased risk for thrombosis, whereas patients with single positive test results may have little to no increased risk. The frequency of triple positivity in outpatients with various combinations of LAC test results is unclear.
  
  
  METHODS
  We extracted from our database all LAC test results [dilute Russell viper venom times (dRVVT) and silica clotting times (SCT)] that had concomitant serum IgG aPL testing [both serum anti β2-glycoprotein I (anti-β2GPI) and anti-cardiolipin (aCL) antibodies].
  
  
  RESULTS
  There were 3195 patients without a prolonged prothrombin time. Double antibody positivity was found in 1% (31/2955) of those with normal functional LAC test results, in 16.0% (31/81) of those with a positive dRVVT, in 12.7% (10/79) of those with a positive SCT, and in 56.3% (45/80) of those with both tests positive (p<0.001). A triple positive aPL antibody profile was found in 28.3% (68/240) of those with at least one positive LAC test result.
  
  
  CONCLUSIONS
  We conclude that 28% of patients with elevated LAC tests have a triple positive aPL antibody profile and patients with two positive LAC tests have a higher prevalence of a triple positive profile than do those with one positive LAC test result.
authors.forename: Paul
authors.initials: P
authors.lastname: Froom
authors.forename: Enas
authors.initials: E
authors.lastname: Saffuri-Elias
authors.forename: Orit
authors.initials: O
authors.lastname: Rozenberg
authors.forename: Mira
authors.initials: M
authors.lastname: Barak
mesh_terms: D000328:Adult; D001774:Blood Chemical Analysis / Q000379:methods*; D001777:Blood Coagulation; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016682:Lupus Coagulation Inhibitor / Q000097:blood*; D008297:Male; D010045:Outpatients; D011237:Predictive Value of Tests; D011517:Prothrombin Time
chemical_list: D007074:Immunoglobulin G; D016682:Lupus Coagulation Inhibitor