Discontinuation of anticoagulation or antiaggregation treatment may be safe in patients with primary antiphospholipid syndrome when antiphospholipid antibodies became persistently negative.

Recommended treatment for patients with primary antiphospholipid syndrome (APS) after a thrombotic event is long-term anticoagulation. Few patients with APS and previously positive antiphospholipid antibodies (aPL) may become negative over time. It is still not exactly known how to treat these patients when aPL become persistently negative. We described the follow-up of 11 primary APS patients whose aPL become persistently negative and in whom thromboprophylaxis was discontinued. The primary end-point was the recurrence of thrombosis in patients with previous thrombotic event and a first thrombotic event in women with previous obstetric APS. Ten (90%) patients were female. Seven (64%) patients had a history of deep venous thrombosis, two of them with pulmonary embolism, and four (36%) women had recurrent miscarriage. Lupus anticoagulant (LAC) was the aPL most frequently detected (82%). Two patients had both LAC and IgG anticardiolipin antibodies. No new thrombotic episode was observed after a median follow-up period of 20 months. Anticoagulation or antiaggregation could be discontinued in some peculiar patients with low-risk primary APS whose aPL become persistently negative. However, studies including a larger number of patients are required to confirm these results.