Antiphospholipid antibody tests: spreading the net

• Published in: Annals of the rheumatic diseases 2005-11, Vol.64 (11), p.1639-1643
• Main Authors: Bertolaccini, M L, Gomez, S, Pareja, J F P, Theodoridou, A, Sanna, G, Hughes, G R V, Khamashta, M A
• Format: Article
• Language: English
• Subjects: aCL; Adult; Antibodies, Anticardiolipin - blood; Antibodies, Antiphospholipid - blood; anticardiolipin antibodies; Anticoagulants; antiphospholipid antibodies; antiphospholipid syndrome; Antiphospholipid Syndrome - complications; Antiphospholipid Syndrome - diagnosis; antiprothrombin antibodies; aPL; APS; aPS-PT; aPT; beta 2-Glycoprotein I; Biological and medical sciences; Biomarkers - blood; Cellulose acetate; coagulation; confidence interval; Confidence intervals; Extended Report; Female; Glycoproteins - immunology; Health risk assessment; Hematologic and hematopoietic diseases; Humans; Immunoglobulin G - blood; Immunoglobulin M - blood; Immunoglobulins; Laboratories; Lupus; lupus anticoagulant; Lupus Coagulation Inhibitor - blood; Lupus Erythematosus, Systemic - complications; Lupus Erythematosus, Systemic - immunology; Male; Medical sciences; Middle Aged; odds ratio; phosphatidylserine-prothrombin complex; Platelet diseases and coagulopathies; Pregnancy; Proteins; prothrombin; Prothrombin - immunology; SLE; Statistical analysis; systemic lupus erythematosus; Thrombosis; Thrombosis - etiology; Thrombosis - immunology; β2-glycoprotein I; β2GPI
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/ard.2005.035824

Objective: To examine the hypothesis that testing for new antiphospholipid antibody specificities may help to identify the antiphospholipid syndrome (APS) in patients with systemic lupus erythematosus (SLE) with thrombosis who are repeatedly negative for anticardiolipin antibodies (aCL) and/or lupus anticoagulant (LA). Methods: Three groups of patients with SLE were studied: (a) SLE/APS (n = 56): 51 female, mean (SD) age 46 (11) years, fulfilling 1999 Sapporo criteria for the APS; (b) SLE/thrombosis (n = 56): 53 female, age 42.6 (12) years, all with a history of thrombosis and persistently negative for aCL and/or LA; (c) SLE only (n = 56): 53 female, age 40 (11) years, without a history of thrombotic events. aCL and LA were retested in all samples. All patients were tested for anti-β2-glycoprotein I (anti-β2GPI) and antiprothrombin antibodies (aPT) by coating prothrombin on irradiated plates or using phosphatidylserine-prothrombin complex as the antigen (aPS-PT). Results: Anti-β2GPI were only present in patients from the SLE/APS group, all of whom were also positive for aCL. aPT and aPS-PT were also more commonly found in SLE/APS than in SLE/thrombosis or SLE only groups (54% v 5%, p