beta 2-Glycoprotein I reactivity of monoclonal anticardiolipin antibodies from patients with the antiphospholipid syndrome.
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.
Ichikawa
K
K
The Rayne Institute, St. Thomas' Hospital, London, UK.
Khamashta
M A
MA
Koike
T
T
Matsuura
E
E
Hughes
G R
GR
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
D017153:Antibodies, Anticardiolipin; D000911:Antibodies, Monoclonal; D006023:Glycoproteins; D010743:Phospholipids; D053482:beta 2-Glycoprotein I; D004247:DNA