IMPAIRED FIBRINOLYSIS IN TRIPLE-POSITIVE ANTIPHOSPHOLIPID ANTIBODY PATIENTS: EVIDENCE OF DELAYED AND INEffECTIVE CLOT RESOLUTION

Antiphospholipid Syndrome (APS) is associated with a persistent prothrombotic state. The Triple- Positive Antiphospholipid Antibodies profile is characterized by the presence of Lupus Anticoagulant (LA), anticardiolipin antibodies (aCL), and anti-β2 glycoprotein I antibodies. This profile is considered a high-risk feature for APS due to its propensity to thrombotic events. Antiphospholipid antibodies may interfere with fibrinolysis, impairing fibrin clot degradation. To assess fibrinolysis in triple-positive antiphospholipid antibody patients. Blood samples from patients investigated for APS at the Coagulation Outpatient Clinic, University of Campinas, were compared with age- and sex-matched healthy controls. A global fibrinolysis resistance assay, based on six parameters, was applied to assess clot formation and lysis. Associations with lupus anticoagulant, anticardiolipin, and anti-β2 glycoprotein I antibodies were analyzed. Twenty triple-positive antiphospholipid antibody patients were included. Compared with 20 health individuals as a control, patients showed a significantly longer time to clot initiation (median: 9.0 min [6.0–7.3] vs. 2.3 min [2.7–2.8]; p = 0.003), slower maximum clot formation rate (184.0 [128.0–211.0] vs. 92.7 [47.7–69.5]; p < 0.001), and a threefold prolonged clot lysis time (9.7 [8.0–12.0] vs. 3.4 [3.0–3.7]); p < 0.001). Triple-positive antiphospholipid antibody patients exhibit markedly delayed and ineffective fibrinolysis, favoring the formation of more persistent and resistant fibrin. These alterations may contribute to recurrent thrombotic events and obstetric complications. Findings highlight the need for closer monitoring of triple-positive antiphospholipid antibody patients and warrant further studies on fibrinolysis-targeted therapeutic strategies.