title: The role of lupus anticoagulant and triple marker positivity as risk factors for rethrombosis in patients with primary antiphospholipid syndrome.
abstract: OBJECTIVE
  To ascertain rethrombotic risk factors in patients with primary antiphospholipid syndrome (PAPS).
  
  
  METHODS
  We retrospectively evaluated 95 patients according to their rethrombotic status. We registered anticoagulation (OA) status, comorbidities, traditional thrombotic factors, prevalence of aCL (IgG-IgM), anti-β2GP-I (IgG-IgM), LA and triple marker positivity (LA, aCL and anti-β2GP-I).
  
  
  RESULTS
  Forty-two patients had rethrombosis and 53 were rethrombosis-free. The median follow-up was 4.5 (0.3-26) years. There were no differences in comorbidities and traditional thrombotic factors. Patients with rethrombosis had more frequently LA (62% vs. 40%, p=0.04), were younger (41 vs. 47 years, p=0.01) and received less frequently OA (23% vs. 54%, p=0.002). A logistic regression analysis showed that the OA status (OR 0.17, 95% CI 0.05-0.57, p=0.004) and age (OR 0.94, 95% CI 0.90-0.98, p=0.01) remained significant. Patients who discontinued OA and developed rethrombosis (Group 1, n=32) vs. patients who discontinued OA, but remained rethrombosis-free (Group 2, n=24) were also analysed. We found a higher prevalence of LA and triple marker positivity in Group 1 (67% vs. 31%; OR= 4.5, 95% CI 1.3-14.9, p= 0.01 and 57% vs. 27%; OR 3.6, 95% CI 1.7-12; p=0.03), respectively. Both variables remained associated with rethrombosis when compared with the overall rethrombosis group vs. Group 2 (LA 62% vs. 31%, OR= 3.6 95% CI 1.1-11.2, p=0.03; triple marker 54% vs. 27%; OR 32 95% CI 1.01-10.2, p=0.05).
  
  
  CONCLUSIONS
  LA positivity and triple aPL positivity confer a more severe risk of rethrombosis in PAPS patients, irrespective of their anticoagulation status and known conventional risk factors.
authors.affiliation: Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. gabyhm@yahoo.com
authors.forename: Gabriela
authors.initials: G
authors.lastname: Hernández-Molina
authors.forename: Grissel
authors.initials: G
authors.lastname: Espericueta-Arriola
authors.forename: Antonio R
authors.initials: AR
authors.lastname: Cabral
mesh_terms: D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000276:immunology*; D000925:Anticoagulants / Q000627:therapeutic use*; D016736:Antiphospholipid Syndrome / Q000150:complications / Q000276:immunology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D053208:Kaplan-Meier Estimate; D016682:Lupus Coagulation Inhibitor / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000209:etiology / Q000276:immunology / Q000517:prevention & control*; D053482:beta 2-Glycoprotein I / Q000276:immunology*
chemical_list: D017153:Antibodies, Anticardiolipin; D000925:Anticoagulants; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016682:Lupus Coagulation Inhibitor; D053482:beta 2-Glycoprotein I