PB0757 - Comparison of clinical and serological features in thrombotic antiphospholipid syndrome patients, with and without associated SLE, followed for up to 42 years: a single centre retrospective study

Monday, June 26, 2023

18:30 – 19:30 ET

Room: Exhibition

Presenting Author(s)

PM

Prabal Mittal

Clinical research Fellow
Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom

Co-Author(s)

MP

Marina Pacheco

Visiting Clinical Fellow
Department of Rheumatology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom
LT

Laura Trives-Folguera

Visiting Clinical Fellow
Department of Rheumatology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom
Jr

Joana rua

Visiting Clinical Fellow
Department of Rheumatology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom
Ibrahim Tohidi-Esfahani, BMed FRACP FRCPA

Clinical research Fellow
Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom
Hannah Cohen, MD

Professor of Haematology and Consultant Haematologist
Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom
ME

Maria Efthymiou

Senior Research Fellow
Haemostasis Research Unit, Department of Haematology, University College London, London, UK
London, England, United Kingdom
DI

David Isenberg

Emeritus Professor of Rheumatology and Consultant Rheumatologist
Department of Rheumatology, University College London Hospitals NHS Foundation Trust, London, UK
London, England, United Kingdom

Background: The impact of concomitant systemic lupus erythematosus (SLE) on the clinicopathological manifestations of thrombotic antiphospholipid syndrome (APS) is undefined.

Aims: To characterise clinical and laboratory features of patients with SLE-associated APS (SLE-APS) compared to primary APS (PAPS), focusing on long-term thrombotic outcomes and antiphospholipid antibody (aPL) profiles.

Methods: In this single-centre, retrospective study, data were collected from medical records of 118 patients, 58 with SLE-APS and 60 with PAPS.

Results: Median follow-up was 13.9 (IQR 7.7–19.3) and 8.6 years (3.5–10.6) for the SLE-APS and PAPS cohorts, respectively. APS was diagnosed significantly earlier in the SLE-APS cohort (mean 35.9 vs PAPS: 46.7 years; p< 0.05). Distribution of aPL subtypes was similar in both cohorts. 198 thrombotic events were identified overall (index plus recurrent), with venous thromboembolism (VTE) and arterial thrombosis each occurring in just over half of patients in both cohorts (Table 1). Microvascular thrombosis (12.1% vs 0%), and a mixed (any combination of venous, arterial and microvascular) thrombotic phenotype (19.0% vs 6.7%, p=0.05) were significantly more prominent in the SLE-APS group. Recurrent thrombosis incidence rates (~0.5 events/10-patient-years), and Kaplan-Meier recurrence-free survival after first thrombosis (Figure-1A), were similar in both cohorts.

In the PAPS cohort, only: (i) triple-aPL-positivity was associated with a significantly higher recurrent thrombosis rate (incidence rate ratio 2.22, p=0.03) and lower recurrence-free survival after first thrombosis (log-rank test p=0.01, hazard ratio 3.2 (95% CI 1.03-11.1), Figure-1B); (ii) in lupus anticoagulant (LA)-positive patients, arterial thrombosis was significantly more prevalent (RR 2.69, p=0.01), and VTE significantly less (RR 0.48, p< 0.001), compared to LA-negative patients.

Conclusion(s): Concomitant SLE does not appear to modify long-term recurrent thrombosis risk, or aPL phenotypes, in patients with APS. However, in SLE-APS patients versus PAPS, risk of microvascular and mixed thrombotic phenotypes may be increased; and triple-aPL-positivity and LA-positive status may have less influence on thrombotic outcomes.