Antiphospholipid autoantibodies have become very heterogeneous

The term antiphospholipid antibodies (aPLs) includes a heterogeneous family of antibodies directed towards various antigens such as anionic or zwitterionic phospholipids but also protein-phospholipid complex and even proteins alone. Some of them are called conventional antibodies and are recognized as laboratory criteria of the antiphospholipid syndrome (APS): anticardiolipin and anti-beta(2)-glycoprotein I antibodies and lupus anticoagulant. The persistent presence of one of these antibodies is sufficient for the diagnosis of APS but none of them is specific of APS and the sensitivity for the clinical abnormalities is variable according to the antibody or according to the antigenic target of the same antibody. So, the heterogeneous character as much clinical as biological of APS makes difficult the diagnosis. Other aPLs were described in patients having clinical features suggestive of APS without any conventional aPLS. Among them, anti-phosphatidylethanolamine and anti-prothrombin antibodies deserve a particular attention because several studies have shown these antibodies to be significantly associated with the clinical events of APS. Thus, the complexity of the biological exploration of APS has greatly increased for some years making essential the use of an algorithm. (C) 2011 Elsevier Masson SAS. All rights reserved.