title: Detection and clinical significance of Ba2+- and Sr2+-dependent antiprothrombin antibodies in patients with systemic lupus erythematosus and antiphospholipid syndrome.
abstract: We conducted this study to confirm whether or not Ca2+-dependent antiprothrombin antibody (aPT) in patients' sera with systemic lupus erythematosus and/or primary antiphospholipid syndrome would react to prothrombin/phosphatidylserine in the presence of Sr2+, Mn2+ or Ba2+, or divalent metal ions like Ca2+, utilizing ELISA, and to analyze the clinical significance of these metal-dependent aPT. We found the presence of Ba2+- and Sr2+-dependent IgG, IgM and IgA-aPT in up to 65% of patients negative for Ca2+-dependent IgG-, IgM and IgA-aPT. Maximally 69% of them were complicated by antiphospholipid syndrome-related symptoms. These data suggest that the measurement of Ba2+- and Sr2+- along with Ca2+-dependent aPT may become a clinically useful tool to correctly detect patients with antiphospholipid-related complications. However, further study is needed to clarify the clinicopathological differences among these aPTs in the future.
authors.affiliation: Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sanaka
authors.forename: J
authors.initials: J
authors.lastname: Matsuda
authors.forename: T
authors.initials: T
authors.lastname: Teramoto
mesh_terms: D000328:Adult; D016736:Antiphospholipid Syndrome / Q000150:complications / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D001464:Barium; D002413:Cations, Divalent; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010718:Phosphatidylserines / Q000276:immunology; D011516:Prothrombin / Q000276:immunology*; D013324:Strontium
chemical_list: D001323:Autoantibodies; D002413:Cations, Divalent; D010718:Phosphatidylserines; D001464:Barium; D011516:Prothrombin; D013324:Strontium