title: A contribution to detection of anticardiolipin and anti-β2glycoprotein I antibodies: Comparison between a home-made ELISA and a fluorescence enzyme immunoassay.
abstract: BACKGROUND
  Currently, ELISA for detection of anticardiolipin (aCL) and anti-β2glycoprotein I (anti-β2GPI) antibodies is not standardized. Recently, few studies have compared the performance of ELISA with that of fluorescence enzyme immunoassay (FEIA), but they have produced debatable results. The aim of this investigation was to compare ELISA with FEIA results in detecting aCL and anti-β2GPI antibodies.
  
  
  METHODS
  The study cohort included 94 primary antiphospholipid syndrome (PAPS) patients, 65 subjects with the clinical criteria for PAPS classification but ELISA negative for the laboratory criteria and 165 control subjects. Serum IgG/IgM aCL/anti-β2GPI antibodies were determined using FEIA-EliA™ and a home-made ELISA.
  
  
  RESULTS
  The sensitivities of the two methods were similar with the exception of IgM aCL which was found to be significantly higher in the PAPS patients using the ELISA method, even if IgM aCL was detected at a low level by both techniques. The two assays had a comparable specificity, a high/significant agreement and a significant correlation between the antibody levels. FEIA testing uncovered no significant prevalence of any antiphospholipid (aPL) antibody in the ELISA negative patients.
  
  
  CONCLUSIONS
  Our results suggest that FEIA is comparable to a home-made ELISA.
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy. Electronic address: elena.mattia80@gmail.com.
authors.forename: Elena
authors.initials: E
authors.lastname: Mattia
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Amelia
authors.initials: A
authors.lastname: Ruffatti
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Lauro
authors.initials: L
authors.lastname: Meneghel
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Tonello
authors.affiliation: Laboratory Medicine Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Faggian
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Ariela
authors.initials: A
authors.lastname: Hoxha
authors.affiliation: Department of Cardiologic, Thoracic, and Vascular Sciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Marny
authors.initials: M
authors.lastname: Fedrigo
authors.affiliation: Rheumatology Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Punzi
authors.affiliation: Laboratory Medicine Unit, Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017153:Antibodies, Anticardiolipin / Q000097:blood*; D016736:Antiphospholipid Syndrome / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards; D005260:Female; D005453:Fluorescence; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards*; D008297:Male; D008875:Middle Aged; D055815:Young Adult; D053482:beta 2-Glycoprotein I / Q000097:blood*
chemical_list: D017153:Antibodies, Anticardiolipin; D015415:Biomarkers; D053482:beta 2-Glycoprotein I
keywords: Anti-β2glycoprotein I antibodies; Anticardiolipin antibodies; ELISA; Fluorescence enzyme immunoassay; Primary antiphospholipid syndrome