Antiphospholipid Antibody Syndrome

Antiphospholipid Antibody Syndrome

Antiphospholipid Antibody Syndrome (APS), also known as Hughes syndrome, is an autoimmune disorder characterized by the presence of antiphospholipid antibodies (aPL) in the blood. These antibodies increase the risk of blood clots (thrombosis) in both arteries and veins, and can lead to complications such as recurrent miscarriages, stroke, and deep vein thrombosis.

Pathophysiology

APS is associated with the production of antibodies against phospholipids, which are essential components of cell membranes. The most common antibodies involved are anticardiolipin antibodies, lupus anticoagulant, and anti-β2 glycoprotein I antibodies. These antibodies interfere with the normal function of the coagulation system, leading to a hypercoagulable state.

Clinical Manifestations

The clinical manifestations of APS can vary widely, but they primarily include:

• Thrombosis: Both venous and arterial thromboses are common. Venous thrombosis often presents as deep vein thrombosis (DVT) or pulmonary embolism (PE). Arterial thrombosis can lead to stroke or myocardial infarction.
• Pregnancy Morbidity: APS is a significant cause of recurrent miscarriages, particularly in the second and third trimesters. It can also lead to preeclampsia and intrauterine growth restriction.
• Thrombocytopenia: A low platelet count is sometimes observed in patients with APS.

Diagnosis

The diagnosis of APS is based on clinical criteria and laboratory findings. The revised Sapporo criteria are commonly used, which require:

• Clinical Criteria: One or more episodes of vascular thrombosis or pregnancy morbidity.
• Laboratory Criteria: The presence of antiphospholipid antibodies on two or more occasions, at least 12 weeks apart.

Treatment

The primary treatment for APS involves anticoagulation therapy to prevent thrombosis. Commonly used medications include:

• Warfarin: A vitamin K antagonist that requires regular monitoring of the international normalized ratio (INR).
• Heparin: Often used in pregnant women with APS due to its safety profile during pregnancy.
• Low-dose Aspirin: Sometimes used in combination with anticoagulants to reduce the risk of thrombosis.

Prognosis

The prognosis for individuals with APS varies depending on the severity of the disease and the effectiveness of treatment. With appropriate management, many patients can lead normal lives, although they may require lifelong anticoagulation therapy.

Also see

• Systemic lupus erythematosus
• Deep vein thrombosis
• Pulmonary embolism
• Autoimmune disorders