Page 55 - Haematologica March 2020

Seronegative antiphospholipid syndrome
Primary and secondary prevention strategies
Antiphospholipid antibody carriers
In subjects with positivity for aPL in the absence of clin- ical thrombotic events, primary prevention strategy includes cardiovascular risk factors such as arterial hyper- tension, diabetes, dyslipidemia and cigarette smoking (Figure 2). Treatment with low-dose aspirin (LDA, 75-100 mg/die) is still controversial6 and could be considered in patients at high risk, such as those with triple positivity or persistent positivity with medium-high titer of aCL.71,72 Recently, the positivity for IgG aPS/PT has been suggested as a marker of thrombotic risk in aPL carriers in addition to triple positivity (Figure 2).58 Regarding oral anticoagula- tion, with or without LDA, the quality of evidence is too low to demonstrate benefit or harm of anticoagulant use in aPL carriers.73
In women with a high-risk aPL profile but no history of thrombosis or pregnancy complications, treatment with LDA (75-100 mg daily) during pregnancy should be con- sidered according to 2019 European League Against Rheumatism (EULAR) recommendations.
Secondary antiphospholipid syndrome
In APS patients with previous arterial or venous throm- boembolism, use of unfractionated or low molecular weight heparins (LMWH) is recommended in the acute phase6 followed by long-term treatment with warfarin, with an international normalized ratio (INR) range between 2-3.8,74
Warfarin therapy in APS has several critical points. Indeed, a recent study10 showed that, in the APS popula- tion, the management of anticoagulant therapy is more problematic compared to a population of patients with
Table 4. Suggested extra-criteria antibodies in seronegative antiphospholipid syndrome and its clinical manifestations.
Extra-critera antibodies
Anti-prothrombin/phosphatidylserine antibodies
Anti-annexin V antibodies/annexin A5 resistance Antibodies to vimentin/CL complex Phosphatidylethanolamine
Phosphatidic acid
Phosphatidylserine
Clinical manifestations
Thrombosis
Thrombosis and/or pregnancy complications Arterial thrombosis
Fetal loss and/or thrombosis
Fetal loss
Fetal loss
Fetal loss
Thrombosis
Phosphatidylinositol
IgA aCL and aβ2GPI antibodies CL:cardiolipin; aβ2GPI: anti- β2 Glycoprotein I.
Figure 2. Summary of antithrombotic treatment options in patients with antiphospholipid syndrome and seronegative antiphospholipid syndrome.72 APS: antiphos- pholipid syndrome; aPL: antiphospholipid antibodies; aCL: anticardiolipin antibodies; VTE: venous thromboembolism; LDA: low-dose aspirin, LMWH: low molecular weight heparin, UFH: unfractionated heparin; INR: international normalized ratio; EULAR: European League Against Rheumatism.
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