Antigen Specificity and Clinical Relevance of Antiphospholipid Syndrome- Related Autoantibodies

Abstract

The presence of antiphospholipid antibodies (aPL) combined with venous or arterial thrombosis, and/or obstetric complications defines the antiphospholipid syndrome (APS). Lupus anticoagulants (LA) and anticardiolipin antibodies (aCL) were the first described aPL. It has been shown that aPL, despite their name, are not directed against anionic phospholipids, as had previously thought, but are a part of a large family of autoantibodies against phospholipid-binding plasma proteins. The most important and relevant antigenic targets involved in APS are β 2 glycoprotein I (β 2 GPI) and prothrombin. However, an increasing number of other phospholipid-binding proteins with crucial functions in the regulation of blood coagulation and fibrinolysis are also targeted by APS-related autoantibodies. For clinical purposes, it is important to find which aPL markers has the best prognostic value. While it has been clearly demonstrated that LA and, to a lesser extent, aCL represent a risk for thrombosis, the role of antibodies directed against β 2 GPI, prothrombin as well as other targets is still uncertain and controversial. Data from a prospective study showed the presence of antibodies to prothrombin and/or β 2 GPI is a predictor of first or recurrent thromboembolic events in patients with LA and/or aCL. This review intends to highlight the antigen specificity and clinical relevance of APSrelated aPL.

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“…The primary inhibitor of FVIIa/TF is tissue factor pathway inhibitor (TFPI). Interestingly, previous studies have shown that antithrombin (AT) inhibits FVIIa and FVIIa/ TF in the presence of heparin [1][2][3][4][5]. However, only limited information is known about the role of other serine protease inhibitors (Serpins) in regulating FVIIa and FVIIa/TF activity.…”

“…The APS-associated aPL are autoantibodies directed against b 2 glycoprotein I (anti-b 2 GPI) and prothrombin [2]. aPL are also found to be positive in patients with viral as well as bacterial infections.…”

Laboratory Criteria of Antiphospholipid Syndrome Need to be Updated or Strictly Followed?~!2009-09-24~!2009-09-28~!2010-03-11~!

“…Considering anti 2 GPI, it was early described an association between the presence of these antibodies and thrombosis [86] and it is well known that they correlated very well with clinical manifestations of APS [6,9,23,87]. For this reason anti 2 GPI were included in the revised criteria for APS [1].…”

“…The other protein that has been recognized as a protein antigen involved in APS is human prothrombin (PT) [5]. Many other proteins with high affinity for PL have been found to be recognized by serum of many patients with APS: Annexin A5, Protein S, TFPI, etc, but these assays have not become clinical useful [6].…”

GOMOZIGOTNAYa MUTATsIYa V GENE INGIBITORA AKTIVATORA PLAZMINOGENA 1 U PATsIENTOV S ANTIFOSFOLIPIDNYM SINDROMOM

“…В то же время ИАП 1 является белком острой фазы, отмечалось повыше-ние его содержания в острый период инфаркта миокарда, при сепсисе и воспалительных заболеваниях [14,15]. Во всех исследованиях, проводимых в данной области, бы-ло показано, что у пациентов с СКВ и ВА активность ИАП 1 значительно повышена [16,17].…”