title: beta 2-Glycoprotein I reactivity of monoclonal anticardiolipin antibodies from patients with the antiphospholipid syndrome.
abstract: OBJECTIVE
  To elucidate the specificity of anticardiolipin antibodies (aCL) from patients with the antiphospholipid syndrome (APS) to various phospholipids (PLs), DNA, and beta 2-glycoprotein I (beta 2-GPI).
  
  
  METHODS
  Five monoclonal aCL were established from peripheral blood lymphocytes of 3 patients with the APS. The reactivity of monoclonal aCL with various PLs, with DNA, and with beta 2-GPI was examined by enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  All of the monoclonal aCL bound to anionic PLs, only in the presence of beta 2-GPI. Neither monoclonal aCL nor beta 2-GPI bound to DNA. Monoclonal aCL bound to solid-phase beta 2-GPI on polystyrene ELISA plates that had carboxyl groups on their surface, but did not react with solid-phase beta 2-GPI on ordinary polystyrene plates. A mixture of beta 2-GPI and CL inhibited the binding of monoclonal aCL to beta 2-GPI, but CL or beta 2-GPI alone did not.
  
  
  CONCLUSIONS
  Monoclonal aCL may recognize a cryptic epitope, which appears as a result of beta 2-GPI binding to anionic PLs or to polystyrene with carboxyl groups.
authors.affiliation: The Rayne Institute, St. Thomas' Hospital, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Ichikawa
authors.forename: M A
authors.initials: MA
authors.lastname: Khamashta
authors.forename: T
authors.initials: T
authors.lastname: Koike
authors.forename: E
authors.initials: E
authors.lastname: Matsuura
authors.forename: G R
authors.initials: GR
authors.lastname: Hughes
mesh_terms: D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000187:drug effects / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000187:drug effects / Q000276:immunology*; D000918:Antibody Specificity; D016736:Antiphospholipid Syndrome / Q000276:immunology*; D004247:DNA / Q000276:immunology; D005260:Female; D006023:Glycoproteins / Q000276:immunology / Q000494:pharmacology*; D006801:Humans; D010743:Phospholipids / Q000276:immunology; D053482:beta 2-Glycoprotein I
chemical_list: D017153:Antibodies, Anticardiolipin; D000911:Antibodies, Monoclonal; D006023:Glycoproteins; D010743:Phospholipids; D053482:beta 2-Glycoprotein I; D004247:DNA