title: Prevalence of antiphospholipid and antioxidized low-density lipoprotein antibodies in rheumatoid arthritis.
abstract: Antiphospholipid antibodies characterize the antiphospholipid syndrome (APS), but they can also be found in various autoimmune, infectious, and malignant conditions. This study's objectives were to detect the prevalence of antiphospholipid and antioxidized low-density lipoprotein (anti-oxLDL) antibodies among patients with rheumatoid arthritis (RA) who did not have clinical manifestations of APS. Using a standard enzyme-linked immunosorbent assay (ELISA), we evaluated the levels of immunoglobulin G (IgG) and IgM anticardiolipin, IgG, and IgM anti-beta-2-glycoprotein-I (anti-beta(2)GPI), and anti-oxLDL autoantibodies in 82 patients with RA. The cutoff levels for detecting these autoantibodies were 15 IgG phospholipid units (GPL), 15 IgM phospholipid units (MPL), and 25 ELISA units (EU)/mL, respectively. Elevated levels of IgG anticardiolipin antibodies were detected in 17 of 82 (21%) RA patients, including 10 with low levels of IgG anticardiolipin and 7 with medium to high levels of anticardiolipin autoantibodies. IgM anticardiolipin was found in only 1 (1%) patient, and both IgG and IgM anti-beta(2)GPI were found in 3 (4%) patients with RA. Elevated levels of anti-oxLDL antibodies were found in 8 (10%) patients, 4 of whom also had elevated levels of IgG anticardiolipin. We conclude that IgG anticardiolipin autoantibodies can be found in about one-fifth of RA patients who do not have clinical manifestations of APS. Whether the presence of anticardiolipin signifies increased risk for thrombosis and atherosclerosis in these patients should be studied further.
authors.affiliation: Department of Medicine B and Center of Autoimmune Diseases, Sheba Medical Center, Tel Hashomer 52621, Israel.
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Sherer
authors.forename: Roberto
authors.initials: R
authors.lastname: Gerli
authors.forename: Gaetano
authors.initials: G
authors.lastname: Vaudo
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Schillaci
authors.forename: Boris
authors.initials: B
authors.lastname: Gilburd
authors.forename: Andrea
authors.initials: A
authors.lastname: Giordano
authors.forename: Elena Bartoloni
authors.initials: EB
authors.lastname: Bocci
authors.forename: Rosita
authors.initials: R
authors.lastname: Allegrucci
authors.forename: Simona
authors.initials: S
authors.lastname: Marchesi
authors.forename: Elmo
authors.initials: E
authors.lastname: Mannarino
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Shoenfeld
mesh_terms: D017153:Antibodies, Anticardiolipin / Q000097:blood*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008077:Lipoproteins, LDL / Q000276:immunology*; D053482:beta 2-Glycoprotein I
chemical_list: D017153:Antibodies, Anticardiolipin; D001323:Autoantibodies; D006023:Glycoproteins; D007074:Immunoglobulin G; D008077:Lipoproteins, LDL; D053482:beta 2-Glycoprotein I; C099252:oxidized low density lipoprotein