Anti phospholipid syndrome Flashcards
What is it?
autoimmune disorder characterised by arterial and venous thrombosis, adverse pregnancy outcomes (for mother and foetus), and raised levels of antiphospholipid antibodies. While it can occur as a primary condition, it often occurs secondary to systemic lupus erythematosus (SLE).
Features
Clots - Usually venous thromboembolism (eg. deep venous thrombosis or pulmonary embolism), but arterial embolism (eg. myocardial infarction or stroke) can also occur.
Livedo reticularis - A mottled, lace-like appearance of the skin on the lower limbs.
Obstetric loss - Recurrent miscarriages, pre-eclampsia and premature births can occur.
Thrombocytopenia.
In addition cardiac valve disease can occur, usually aortic and mitral regurgitation ± stenosis.
Investigations?
One or more of the following positive blood tests are needed on 2 occasions, 12-weeks apart to diagnose APS:
Anti-cardiolipin antibodies.
Anti-beta2-GPI antibodies.
Positive lupus anticoagulant assay.
Note - syphilis can cause false positive tests for the above, and so should be excluded with treponemal serology.
FBC - Thrombocytopenia often occurs in APS.
Methods to reduce risk factors for thromboembolism
Venous - Avoid oestrogen-containing contraception / hormone replacement therapy and long periods of immobility.
Arterial - Control cardiovascular risk factors (eg. smoking, blood pressure, cholesterol, blood glucose).
Treatment of thromboembolism in antiphospholipid syndrome
Treatment is not recommended prophylactically in patients that have not experienced a thromboembolic event.
Those that do have an event should receive anticoagulation in the normal way eg. warfarin / NOAC. When anticoagulation is started in APS, it is usually life-long.
The use of warfarin in antiphospholipid syndrome
As warfarin is teratogenic and there is a large risk to the foetus in APS, alternate forms of anticoagulation during pregnancy are needed such as low molecular weight heparin.
