Antiphospholipid Syndrome

Antiphospholipid Syndrome

Antiphospholipid Syndrome (APS) important in vascular medicine as well as obstetrics. In obstetrics, it is important because it can cause fetal loss, intrauterine growth retardation and severe preeclampsia. In vascular medicine it is important because it can cause thrombotic events which could be arterial, venous or microvascular [1]. It can also be accompanied by moderate thrombocytopenia [2]. Thrombotic events involving multiple organs may be termed catastrophic Antiphospholipid Syndrome [3].

APS is an autoimmune disease with antibodies directed against beta2 glycoprotein I. This leads to suppression of tissue factor pathway inhibitor, activates complement and reduces the levels of protein C activity, all leading to thrombotic episodes. APS may occur with or without other systemic autoimmune diseases like systemic lupus erythematosus (SLE). Of the three important antibodies, lupus anticoagulant has better correlation with clinical events than anti beta2 glycoprotein I antibodies and anticardiolipin antibodies.

There is no consensus on giving aspirin for primary prevention in those with no thrombotic episodes yet. Heparin and warfarin are recommended for those with a history of venous thrombosis. Just as in other cases of unprovoked venous thrombosis, anticoagulation has to be probably continued life long. It may be noted that falsely elevated international normalized ratio (INR) may occur with certain types of tests in APS. Warfarin is often recommended for arterial thrombosis as well, though patients with stroke and low levels of anticardiolipin antibodies may even be treated with aspirin alone.

In pregnancy with thrombotic episodes, low dose aspirin and full dose of heparin or low molecular weight heparin are given. Low dose of aspirin or prophylactic dose of heparin are preferred in pregnancy with no prior thrombotic episodes. This may be continued six weeks after delivery.


  1. Garcia D, Erkan D. Diagnosis and Management of the Antiphospholipid Syndrome. N Engl J Med 2018; 378:2010-2021.
  2. Gómez-Puerta JA, Cervera R. Diagnosis and classification of the antiphospholipid syndrome. J Autoimmun. 2014 Feb-Mar;48-49:20-5.
  3. Cervera R, Rodríguez-Pintó I; G Espinosa on behalf of the Task Force on Catastrophic Antiphospholipid Syndrome. Catastrophic antiphospholipid syndrome: task force report summary. Lupus. 2014 Oct;23(12):1283-5.