125- Antiphospholipis Syndrome: clinical features and diagnosis
Autor(s): M. Galli
Issue: RIMeL - IJLaM, Vol. 5, N. 2, 2009 (MAF Servizi srl ed.)
Page(s): 125-130
The antiphospholipid antibodies syndrome (APS) is defined by the combination of thrombotic events (venous and / or arterial) and /or pregnancy-related complications and at least one of the 3 most common antiphospholipid antibodies (aPL) (lupus anticoagulant, LAC; anticardiolipin antibodies, aCL-Ab, IgG and / or IgM; antibodies versus b 2-glycoprotein I, aβ2GPI, IgG and /or IgM. The presence of aPL is essential for the correct diagnosis of APS. Clinical studies have shown that LAC is more strongly associated with risk of arterial and venous thrombosis rather than to CL and β2GPI antibodies. The LAC-β2GPI-dependent antibody seems to be the most important antibody in the risk of thrombosis, on the contrary the LAC-β2GPI-independent antibody (LAC prothrombin dependent) does not increase the thrombotic risk in patients. Asymptomatic APL-positive subjects do not require antithrombotic prophylaxis, because their risk of first event is <1% patients per year. Prophylaxis is recommended in case of surgery, prolonged immobility or in other situations of increased risk of thrombosis, and the removal or correction of the acquired thrombotic risk factors if possible. The recurrence of deep vein thrombosis (DVT) in patients with APS has a prevalence between 22 and 69%. The type of thrombosis is often predictive of the subsequent events. The long-term anticoagulation with moderate-intensity warfarin (PT INR 2,0 and 3,0) reduces the risk of thrombotic recurrence by 80 to 90%. It is still uncertain what is the most suitable treatment of the recurrence of DVT while under warfarin therapy. Possible options are: low molecular weight heparin or unfractioned heparin, high-intensity warfarin (PT INR 3,0-4,0) or warfarin with anti-platelet drugs. Patients who had an arterial thrombosis have a yearly risk of recurrence around 11%, indepedently from the type of secondary prophylaxis with intermediate-intensity warfarin (PT INR 1,4-2,8) or aspirin (325 mg / day). Key-words: Antiphospholipid Syndrome, diagnostic criteria, Lupus anticoagulant, β2-glycoprotein I, Anticardiolipin antibodies.