Antiphospholipid Syndrome

Question 1

Definition

Answer 1

Characterised by the presence of antiphospholipid antibodies (APL) in the plasma,
venous and arterial thrombosis, recurrent foetal loss and thrombocytopaenia

Question 2

Aetiology

Answer 2

• Antiphospholipid antibodies (APL) are directed against plasma proteins bound to
phospholipids
• APL may develop in susceptible individuals following exposure to infectious agents
• Once APL are present, a second event is needed for the syndrome to develop
• APL has effects on a number of coagulation factors (e.g. protein C, annexin V, platelets,
fibrinolysis)
• Complement activation by APL is critical for the complications

Question 3

Epidemiology

Answer 3

• More common in YOUNG WOMEN
• Accounts for 20% of strokes in < 45 yrs
• Accounts for 27% of women with > 2 miscarriages

Question 4

Presenting symptoms

Answer 4

• RECURRENT MISCARRIAGES

• Headaches (migraine)
• Chorea
• Epilepsy

• History of:
o Arterial thromboses (stroke)
o Venous thromboses (DVT, PE)

Question 5

Signs on physical examination

Answer 5

• Livedo reticularis
o A skin finding consisting of a mottled reticulated vascular pattern that appears as
a lace-like purplish discolouration of the skin

• Signs of SLE (e.g. malar rash, discoid lesions)
• Signs of valvular heart disease

Question 6

Investigations

Answer 6

• FBC - low platelets
• ESR - usually normal
• U&Es - can get APL nephropathy
• Clotting screen - high APTT

• Presence of antiphospholipid antibodies may be demonstrated by:
o ELISA testing for anticardiolipin antibodies
o Lupus anticoagulant assays