Antiphospholipid Syndrome

Question 1

What is antiphospholipid syndrome?

Answer 1

An acquired disorder characterised by a predisposition to:

• Venous and arterial thromboses
• Recurrent fetal loss
• Thrombocytopenia.

Question 2

It can occur as a primary or secondary condition. What condition is it often secondary to?

Answer 2

Systemic Lupus Erythematosus (SLE)

Question 3

What does antiphospholipid syndrome do to APTT?

Answer 3

It causes a paradoxical rise in the APTT.

This is due to an ex-vivo reaction of the lupus anticoagulant autoantibodies with phospholipids involved in the coagulation cascade

Question 4

What are some features of antiphospholipid syndrome?

Answer 4

• Venous/arterial thrombosis
• Recurrent fetal loss
• Livedo reticularis
• Thrombocytopenia
• Prolonged APTT
• Other features: pre-eclampsia, pulmonary hypertension

Question 5

What other conditions, apart from SLE, is antiphospholipid syndrome associated with?

Answer 5

• Other autoimmune disorders
• Lymphoproliferative disorders
• Phenothiazines (rare)

Question 6

According to the BCSH guidelines, how is antiphospholipid syndrome managed?

Answer 6

• VTE
  
  • Initial: Treat with warfarin with a target INR of 2-3 for 6 months
  • Recurrent: lifelong warfarin. INR 2-3.
    
    • ​If occurred whilst taking warfarin then increase target INR to 3-4
• Arterial thrombosis - Lifelong warfarin with target INR 2-3

Question 7

What complications may occur in pregnancy?

Answer 7

• Recurrent miscarriage
• IUGR
• Pre-eclampsia
• Placental abruption
• Pre-term delivery
• Venous thromboembolism

Question 8

How is antiphosphoplipid syndrome managed in pregnancy?

By how much does management increase the chance of a live birth rate?

Answer 8

• Low dose aspirin once pregnancy is confirmed on urine test.
• LMWH once fetal heart seen on USS.
  
  • LMWH stopped at 34 weeks.

This increases the chances of live birth x7.