title: Methods for subtyping lupus anticoagulants.
abstract: Two simple procedures were tested for their potential to identify beta2-glycoprotein 1 (beta2GP1) or prothrombin cofactor dependence among lupus anticoagulants (LA). The first comprised mixing test plasma 1:4 with beta2GP1-deficient plasma instead of with normal plasma. beta2GP1 deficiency decreased, but did not abolish most LA detectable in KCT, DRVVT and APTT clotting tests. Mixing 1:4 with bovine plasma was evaluated in a second test based on the KCT in the expectation that prothrombin-dependent LA would be preferentially shortened. Bovine plasma had a similar correcting effect on LA in all three tests considered here. Conversely, a prothrombin antibody was found to have similar prolonging effect on all three of these tests. LA patient plasmas displayed considerable heterogeneity when analysed using a combination of these two tests. The clinical significance of these tests remains uncertain. DRVVT and KCT tests do not appear to discriminate beta2GP1-dependent from prothrombin-dependent LA.
authors.affiliation: Gradipore Ltd, Sydney, Australia.
authors.forename: T
authors.initials: T
authors.lastname: Exner
mesh_terms: D000328:Adult; D000818:Animals; D000918:Antibody Specificity; D001324:Autoantigens / Q000276:immunology; D001780:Blood Coagulation Tests; D002417:Cattle; D005069:Evaluation Studies as Topic; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000032:analysis / Q000145:classification* / Q000276:immunology; D010314:Partial Thromboplastin Time; D011516:Prothrombin / Q000276:immunology; D011517:Prothrombin Time; D053482:beta 2-Glycoprotein I
chemical_list: D001324:Autoantigens; D006023:Glycoproteins; D016682:Lupus Coagulation Inhibitor; D053482:beta 2-Glycoprotein I; D011516:Prothrombin