antiphospholipid syndrome

Question 1

definition of antiphospholipid syndrome

Answer 1

Characterized by the presence of antiphospholipid antibodies (APL) in the plasma, venous and arterial thromboses, recurrent foetal loss and thrombocytopenia.

Question 2

aetiology of antiphospholipid syndrome

Answer 2

APL Ab are directed against plasma proteins bound to anionic phospholipids (e.g.b2 glycoprotein-I a clotting and platelet aggregation inhibitor).

APL may develop in susceptible individuals eg those with rheumatic disease eg SLE, following exposure to infectious agents

once APL are present, need 2nd hit for development of the syndrome

procoagulant effects of APL may be mediated by their effect on B2-GP-1, protein C, annexin V, platelets, fibrinolysis

complement activation is critical for pregnancy complications

Question 3

epidemiology of antiphospholipid syndrome

Answer 3

more common in young female

accounts for 20% strokes in <45yrs

and 27% of women with >2 miscarriages

Question 4

sx of antiphospholipid syndrome

Answer 4

recurrent miscarriages

history of arterial thromboses (stroke)

venous thromboses - DVT, PE

thrombotic tendency affects cerebral, renal and other vessels

headaches - migraine

chorea

epilepsy

Question 5

signs of antiphospholipid syndrome

Answer 5

livedo reticularis

signs of SLE - malar flush, discoid lesions, photosensitivity

signs of valvular heart disease

Question 6

Ix for antiphospholipid syndrome

Answer 6

FBC - low platelets

ESR normal

UE - APL nephropathy from microangiopathic thrombosis (present as oedema and proteinuria)

clotting screen - slow APTT

presence of APL demonstrated by:

• ELISA for anticardiolipin and anti-B2-GPI Ab
• lupus anticoagulant assay
  
  • Clotting assays showing effects of APL on the phospholipid-dependent factors in the coagulation cascade.

False-positive VDRL test for syphilis may be a clue to the presence of any type of APL.

Question 7

what are the antiphospholipid Ab in antiphospholipid syndrome

Answer 7

anticardiolipin and lupus anticoagulant

anti-B glycoprotein 1

Question 8

acronym for effects of antiphospholipid syndrome

Answer 8

CLOTS

c - coagulation defect (arterial/venous)

livedo reticularis

obstetric - recurrent miscarriage

thrombocytopenia

Question 9

diagnosis of antiphospholipid syndrome

Answer 9

persistent antiphospholipid antibodies with clinical features

Question 10

Answer 10

libedo reticularis

pink-blue mottling caused by capillary dilatation and stasis in skin vessels

causes - physiological, cold, vasculitis