AUTHOR=Niznik Stanley , Rapoport Micha J. , Avnery Orly , Lubetsky Aharon , Haj Yahia Soad , Ellis Martin H. , Agmon-Levin Nancy 

TITLE=Patterns of Recurrent Thrombosis in Primary Antiphospholipid Syndrome—Multicenter, Real-Life Long-Term Follow-Up

JOURNAL=Frontiers in Immunology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.843718

DOI=10.3389/fimmu.2022.843718

ISSN=1664-3224

ABSTRACT=Background: Antiphospholipid Syndrome (APS) is an acquired hypercoagulable condition associated with antiphospholipid antibodies (aPLs) presence. Data on re-thrombosis following APS-diagnosis is limited.
Methods: Retrospective analysis of new thrombotic events among primary-APS (pAPS) patients followed for up to 15 years in three medical centres in Israel.
Results: Among 312 primary-APS patients 143 (46%) had new thrombotic event classified to three patterns: (1) Arterial - associated with heart valve disease (OR 7.24, 95% C.I. 2.26-24.6), hypertension (OR 3, 95% C.I. 1.44-6.25), elevated anti B2-GPI IgM (OR 1.04, 95% C.I. 0.996-1.08), arterial thrombosis at presentation (OR 1.74 CI95% 0.992-3.26) and older age (41 vs. 34 years, p<0.001). (2) Venous – linked with venous thrombosis at presentation (OR 12.9, 95% C.I. 5.27-31.6, p<0.001), heart valve disease (OR 9.81 CI95% 1.82-52.9, p=0.018), aGAPSS (OR 1.15 CI95% 1.02-1.29) and younger age (31 vs. 36.5 years, p=0.001); (3) Combined pattern - associated with heart valve disease (OR 40.5 95% C.I. 7.7- 212) and pulmonary embolism (OR 7.47 95% C.I. 1.96-28.5). 
A 4th variant "the Breakthrough pattern" defined by re-thrombosis despite prophylactic therapy was observed in 100/143(70%) patients and linked with heart valve disease (OR 8. 95% C.I. 2.43-26.3), venous thrombosis at presentation (OR 2.61 95% C.I. 1.47-4.66), leg ulcers (OR 12.2, 95% C.I. 1.4-107), hypertension (OR 1.99, 95% C.I. 0.92-4.34) and higher aGAPSS (OR 1.08, 95% C.I. 0.99-1.18).
Conclusion: In this real life observation, re-thrombosis was common among pAPS patients including in those recommended to receive prophylactic therapy. Different patterns of recurrence were identified and linked with presenting symptoms, specific serological markers, APS-manifestations and comorbidities.  Studies that will address interventions to prevent recurrences of APS related events are needed.