title: Antiphospholipid antibodies (aPL) in systemic lupus erythematosus. Are they specific tools for the diagnosis of aPL syndrome?
abstract: OBJECTIVE
  Antiphospholipid antibody (aPL) specificity for aPL-related events was evaluated in systemic lupus erythematosus (SLE).
  
  
  METHODS
  A study was carried out on 105 patients affected with SLE comparing the prevalence of lupus anticoagulant (LA) and IgG and IgM anticardiolipin antibodies (aCL) between patients with and without features of antiphospholipid syndrome (APS). Antiphospholipid antibody profile was subsequently evaluated in the aPL positive patients with and without aPL-related events, thus excluding the patients with complications of APS possibly due to factors other than aPL.
  
  
  RESULTS
  LA showed a strong association with thrombosis and livedo reticularis, and IgG aCL with thrombosis and neurological disorders, while no clinical features were associated with IgM aCL. A considerable number of aPL positive patients with no aPL-related manifestations was also observed, suggesting the low specificity of aPL assays (54.4%). When studying the 60 aPL positive patients, LA was specific (91.3%) for the diagnosis of aPL-related thrombosis, whereas aCL were not specific, although IgG aCL mean levels were higher in patients with arterial thrombosis than in those without APS features.
  
  
  CONCLUSIONS
  LA but not aCL positivity is a specific tool for the diagnosis of thrombotic complications due to aPL in SLE.
authors.affiliation: Division of Rheumatology, University of Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ghirardello
authors.forename: A
authors.initials: A
authors.lastname: Doria
authors.forename: A
authors.initials: A
authors.lastname: Ruffatti
authors.forename: A M
authors.initials: AM
authors.lastname: Rigoli
authors.forename: P
authors.initials: P
authors.lastname: Vesco
authors.forename: A
authors.initials: A
authors.lastname: Calligaro
authors.forename: P F
authors.initials: PF
authors.lastname: Gambari
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017152:Antibodies, Antiphospholipid / Q000097:blood*; D016736:Antiphospholipid Syndrome / Q000175:diagnosis* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D016682:Lupus Coagulation Inhibitor / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013927:Thrombosis / Q000276:immunology
chemical_list: D017152:Antibodies, Antiphospholipid; D015415:Biomarkers; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016682:Lupus Coagulation Inhibitor