Variability in the international normalised ratio (INR) in patients with antiphospholipid syndrome and positive lupus anticoagulant: should the INR targets be higher?
Thesis
Antiphospholipid syndrome (APS) is an autoimmune disorder characterised by hypercoagulability requiring anticoagulant therapy as the basis, with warfarin as the treatment of choice in cases requiring long-term management. However, patients with positive lupus anticoagulant (LA) present a challenge because they have an increasedrisk of thrombotic events, in addition to the fact that the monitoring of the international normalised ratio (INR) is unreliable because these antibodies generate interference with the laboratory tests based on phospholipids, as is the case for prothrombin time (PT) with prolonged baseline INR, even before the start of anticoagulant therapy. For this reason, we present the case of a patient with primary APS and positive LA who had multiple thrombotic events despite receiving anticoagulant therapy.
