Low frequency of phosphatidylserine/prothrombin complex antibodies in a cohort of patients with anticardiolipin antibodies and recent thrombosis

ar641 ARJ Meeting abstract Low frequency of phosphatidylserine/prothrombin complex antibodies in a cohort of patients with anticardiolipin antibodies and recent thrombosis Locht H

Department of Autoimmunology, Statens Serum Institut, Copenhagen, Denmark

Arthritis Res Ther 23rd European Workshop for Rheumatology Research The organizer would like to thank the following companies who have generously supported the 23rd European Workshop for Rheumatology Research: Abbott, Amgen, Aventis, Merck Sharp and Dohme, Novartis, Pharmacia, Schering-Plough, Wyeth Meeting abstracts 23rd European Workshop for Rheumatology Research Marseille, France

27 February – 2 March 2003

1478-6354 2003 5 Suppl 1 11 10.1186/ar641 24 2 2003

Objective

Clinical data from patients who were positive for anticardiolipin antibodies (ACAs), tested on a routine basis in an autoimmune laboratory, were obtained by questionnaires from the referring physicians. One hundred and sixty-two individuals had experienced a recent (within <6 months) thromboembolic event. All sera were tested for IgG and IgM antibodies against cardiolipin, β₂-glycoprotein 1 (β₂-glp 1), and the complex of phosphatidylserine/prothrombin (PPC) by in-house ELISA methods.

Results

Among the 162 ACA-positive patients, 31 (19%) were also positive for antibodies against PPC. In the group with ACA only, 73% of the patients had no pre-existing rheumatic condition, compared with 32% in the PPC group (P = 0.00002). Thirty-two percent in the PPC group had SLE, vs 12% in the ACA group (P = 0.016). The fractions of patients with deep venous thrombosis (DVT), pulmonary embolism (PE), or myocardial infarction (MI) were equal, whereas cerebrovascular incidents (CVI) were more frequent among ACA patients; 51% vs 26% (P = 0.02). Antibodies against β₂-glp 1 were also more frequent in the PPC group 61% vs 30% (P = 0.002).

Conclusion

Antibodies against both ACA and PPC seem to define a subset of patients with autoimmune thrombophilia. More patients with PPC antibodies had SLE and also tested positive for antibodies against β₂-glp 1. The distribution of thrombotic manifestations differed between the two populations in that CVI was more frequent in the ACA-only group, whereas the fractions with DVT, PE, and MI were equal.