ANTIPHOSPHOLIPID SYNDROME Flashcards
Define antiphospholipid syndrome.
Antiphospholipid syndrome (APS) is an autoimmune disorder characterised by arterial and venous thrombosis and is strongly associated with repetitive miscarriage.
What are the antibodies associated with antiphospholipid syndrome?
Anticardiolipin
Lupus anticoagulant
Anti-β2-glycoprotein I
What is cardiolipin?
A negatively charged phospholipid.
What is Lupus anticoagulant?
Despite its name, it is actually a prothrombotic agent which is more associated with antiphospholipid syndrome than lupus (although some SLE patients do have the antibody)
What is the pathogenesis of antiphospholipid syndrome?
Mechanism is believed to be similar to SLE. Negatively charged phospholipids and β2-glycoprotein I, present on the outer surface of apoptotic blebs, are bound by pathogenic antiphospholipid antibodies. When these cells include endothelial cells, platelets, monocytes and trophoblasts the altered function of the cells lead to thrombosis.
How would a patient with suspected antiphospholipid syndrome present?
History of ischaemic events
DVTs happen in 40%
Stroke in 20%
Miscarriage
What percentage of women who have had two or more miscarriages have antiphospholipid syndrome?
27%
Is the thrombosis involved in antiphospholipid syndrome arterial or venous?
Unlike most thrombophilia, APS can cause both.
What is catastrophic antiphospholipid syndrome?
This is when multiple infarcts in different organs cause simultaneous multiple organ failure.
What is the pathogenesis of antiphospholipid syndrome?
Mechanism is believed to be similar to SLE. Negatively charged phospholipids and β2-glycoprotein I, present on the outer surface of apoptotic blebs, are bound by pathogenic antiphospholipid antibodies (aPLs). When these cells include endothelial cells, platelets, monocytes and trophoblasts the altered function of the cells lead to thrombosis.
What is catastrophic antiphospholipid syndrome?
This is when multiple infarcts in different organs cause simultaneous multiple organ failure. There is a high mortality associated with catastrophic antiphospholipid syndrome.
Other than a history of thromboembolic events and a history of miscarriages, what other features do patients with antiphospholipid syndrome present with?
Thrombocytopenia Chorea Migraine Epilepsy Valvular heart disease Cutaneous manisfestations Positive Coombs test Renal impairment
What is the main treatment option for someone diagnosed with anti-phospholipid syndrome?
Long term anticoagulation with warfarin.
Pregnant women with APS are given oral aspirin and subcutaneous heparin from early in gestation.
What prophylaxis treatment might you give to someone found to have anti-phospholipid syndrome who have never had thrombosis?
Aspirin or clopidogrel
What is the target INR of someone on warfarin treatment for anti-phospholipid syndrome?
Evidence suggests that there is no added value of target INR being 3-4 versus 2-3 for patients experiencing venous thromboembolic events. However, for patients experiencing arterial thromboembolic events a target INR of 3-4 is recommended.
