title: Analytical and clinical comparison of different immunoassay systems for the detection of antiphospholipid antibodies.
abstract: BACKGROUND
  We evaluated analytical and clinical performances of IgG and IgM anticardiolipin (aCL) antibodies and anti-β2-glycoprotein I (a-β2GpI) antibodies and upper limit reference ranges (99th percentiles) in comparison with manufacturer's cutoff values with different commercial methods.
  
  
  METHODS
  We assayed aCL and a-β2GpI in serum samples from 30 healthy individuals, 77 patients with antiphospholipid syndrome (APS) diagnosed according to the Sydney criteria, 51 patients with autoimmune diseases, eight patients with previous thrombotic events, six patients with other diseases, and 18 patients with infectious diseases, using ELISA Inova Diagnostics; EliA Phadia Laboratory Systems; CliA Zenit-RA; and CliA Bio-Flash.
  
  
  RESULTS
  Anticardiolipin and a-β2GpI IgG and IgM immunoassays showed good analytic performances with both 99th percentile and manufacturer's cutoff reference values. Our results showed fair to moderate agreement among assays. In-house cutoff values gave significantly better performances only for a-β2GpI IgG with all the immunoassays analyzed with the exception of Inova CliA Bio-Flash where we obtained the same performances with in-house and manufacturer's cutoffs.
  
  
  CONCLUSIONS
  By guidelines, all laboratories are strongly advised to validate/verify the manufacturer's cutoff values. We recommend establishing low-positive, medium-/high-positive, and high-positive CliA IgG aCL and a-β2GpI ranges in order to help clinicians in the diagnosis and treatment of APS.
authors: Laboratory Analysis, AO Ordine Mauriziano, Torino, Italy.
authors: B
authors: B
authors: Montaruli
authors: Laboratory Analysis, AO Ordine Mauriziano, Torino, Italy.
authors: E
authors: E
authors: De Luna
authors: Laboratory Analysis, AO Ordine Mauriziano, Torino, Italy.
authors: L
authors: L
authors: Erroi
authors: Laboratory Analysis, AO Ordine Mauriziano, Torino, Italy.
authors: C
authors: C
authors: Marchese
authors: Laboratory Analysis, Città della Salute e della Scienza, Torino, Italy.
authors: G
authors: G
authors: Mengozzi
authors: Laboratory Analysis, AO Martini, Torino, Italy.
authors: P
authors: P
authors: Napoli
authors: Laboratory Analysis, AO San Luigi Orbassano, Torino, Italy.
authors: C
authors: C
authors: Nicolo'
authors: Laboratory Analysis, AO Maria Vittoria, Torino, Italy.
authors: A
authors: A
authors: Romito
authors: Clinical Immunology, AO Ordine Mauriziano, Torino, Italy.
authors: M T
authors: MT
authors: Bertero
authors: Haematology, AO Ordine Mauriziano, Torino, Italy.
authors: P
authors: P
authors: Sivera
authors: Laboratory Analysis, AO Ordine Mauriziano, Torino, Italy.
authors: M
authors: M
authors: Migliardi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017153:Antibodies, Anticardiolipin / Q000097:blood; D017152:Antibodies, Antiphospholipid / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D016682:Lupus Coagulation Inhibitor / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult; D053482:beta 2-Glycoprotein I / Q000276:immunology
chemical_list: D017153:Antibodies, Anticardiolipin; D017152:Antibodies, Antiphospholipid; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016682:Lupus Coagulation Inhibitor; D011933:Reagent Kits, Diagnostic; D053482:beta 2-Glycoprotein I
keywords: Antiphospholipid syndrome; anti-β2-glycoprotein I antibodies; anticardiolipin antibodies; chemiluminescence assays