Clinical significance of phospholipid-cofactor antibodies in patients with systemic lupus erythematosus-associated antiphospholipid syndrome

Abstract EN

-To establish whether antibodies directed against phospholipid-binding plasma proteins such as β2-glycoprotein I (β2GPI), prothrombin (PT), and Annexin V (AnxV) constitute a risk factor for thrombosis in patients with systemic lupus erythematosus (SLE)-associated antiphospholipid syndrome (SLE/APS). Patients and methods A group of SLE patients (with and without APS) and patients with primary APS (PAPS) were included in this study.

Fifteen patients with deep vein thrombosis but without antiphospholipid (aPL) antibodies, and another 15 age-matched and sex-matched apparently healthy individuals served as a control group.

All patients were investigated for lupus anticoagulants and detection of anticardiolipin (aCL) immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies. Antibodies against β2GPI (IgG and IgM), PT (IgG and IgM), and AnxV (IgG) were also measured using the respective enzyme-linked immunosorbent assays. Results The study included 58 SLE patients (18 SLE/APS patients and 40 patients without APS) as well as 40 patients with PAPS, mean age 43 years (range: 18–74 years).

IgG and/or IgM aCL antibodies were detected in all patients with PAPS (100%), whereas the prevalence rates of aPL-cofactor antibodies were as follows: 75% anti-β2GPI, 70% anti-PT, and 25% anti-AnxV antibodies.

In SLE patients without APS, aCL antibodies were detected in 17.5%, anti-β2GPI antibodies in 20%, anti-AnxV antibodies in 20%, and anti-PT antibodies in 10% of patients.

None of the antibodies measured were detected in deep vein thrombosis cases or healthy controls. Conclusion Measurement of antiphospholipid-cofactor antibodies in addition to the more widely used aCL and anti-β2GPI antibodies could be a useful prognostic marker for the risk of thrombosis in SLE/APS patients.