Journal Article

O35 Timing of thromboembolic events in systemic lupus erythematosus associated to antiphospholipid syndrome; results from a population-based study set in Norway

Wivestad, Gro Å, Lerang, Karoline, Moe, Sigrid R, Botea, Antonela, Damjanic, Nenad, Orre, Anniken, Øvreås, Heidi, Bøe, Thea, Provan, Sella A, Haukeland, Hilde, Molberg, Øyvind, Garen, Torild, Brunborg, Cathrine

2024

Overview

ObjectiveTo estimate occurrence of thromboembolic event in a population-based setting and compare characteristics of new-onset Systemic Lupus Erythematosus (SLE) with and without Antiphospholipid Syndrome (APS).MethodsWe included all new-onset SLE cases residing in the Southeast Norway area 1999–2017. Follow-up ended 31 December 2017.All cases had diagnosis confirmed by chart-review, fulfilled the 2019 EULAR/ACR classification criteria and were captured within one year of diagnosis.All APS fulfilled the 2006 Sapporo classification criteria. Arterial thromboembolic events included ischemic stroke, transient ischemic attack, myocardial infarction or angina pectoris identified either by individual-level chart-review or by ICD-code (G45–46, I63 excluding I63.6, I20-I25, R96) in The National Cause of Death Register. Venous thromboembolic events included syndromes caused by occlusion of major venous vessel identified by chart-review. We estimated incidence rates per 100 person-years at risk and 95% confidence intervals (CI) using Poisson distribution.ResultsOf the 749 cases with new-onset SLE 1999–2017, 84 (11%) had coexisting APS. APS cases were more prone to develop thrombocytopenia, neuropsychiatric disease and anti-dsDNA positivity during the disease course than cases without APS (table 1).By the end of follow-up, 174 (23%) cases had ever experienced at least one arterial or venous event (TE). APS cases were younger at their first TE than those without APS (mean age 37 versus 59, p-value<0.001). TE tended to coincide with SLE diagnosis in APS cases (figure 1).In the 675 cases without previous TE at SLE diagnosis, 38 and 69 TE occurred within one year and five years disease duration. Overall 5-year incidence rate for TE was 2.6 (95% CI 2.0–3.3). APS cases exhibited a high incidence of TE the first year after SLE diagnosis (51.1, 95% 33.4–74.8), that decreased to 8.6 (95% CI 4.7–14.7) one to five year after SLE diagnosis. Cases without APS had a considerable lower first-year incidence of TE (2.3, 95% CI 1.4–3.8) and the decline were not as pronounce (1–5-year incidence 0.8, 95% CI .0.5–1.2).ConclusionsThe risk of APS-related thromboembolic events are high around the time of SLE diagnosis. Awareness of thromboembolic events around the time of SLE diagnosis appear crucial, especially in cases with antiphospholipid antibodies.AcknowledgementsThis work was supported by the The Norwegian Women’s Public Health Association, The DAM Foundation, Vivi Irene Hansens Foundation, Ragna and Egil Eiken`s Foundation and the Norwegian Rheumatism Association.Abstract O35 Figure 1Timing of thromboembolic events in new-onset Systemic Lupus Erythematosus with and without Antiphospholipid SyndromeAbstract O35 Table 1Demographic, cumulative clinical features, medication use and outcome parameters in in new-onset Systemic Lupus Erythematosus with and without Antiphospholipid Syndrome Antiphospholipid Syndromea p-value No Yes Number of cases 665 84 Baseline demographics Age at SLE diagnosis, years µ (SD) 40 (17) 37 (15) 0.116 Female, n (%) 555 (85) 67 (80) 0.216 Of European ancestry, n (%) 549 (83) 74 (88) 0.201 Juvenile-onsetb, n (%) 35 (5) 4 (5) 1.0 Smoking (ever), n (%) 43 (51) 250 (38) 0.016 Cumulative clinical features EA criteriac, score at study end, µ (SD) 22 (8) 25 (8) 0.004 Malar erythema, n (%) 254 (38) 32 (38) 0.931 Oral ulcers, n (%) 189 (28) 27 (32) 0.460 Photo sensibility, n (%) 375 (56) 50 (60) 0.822 Non-erosive arthritis, n (%) 361 (54) 50 (60) 0.365 Hemolytic anemia, n (%) 60 (9) 13 (15) 0.067 Thrombocytopenia, n (%) 132 (20) 28 (33) 0.004 Leukopenia, n (%) 281 (42) 31 (37) 0.484 Serositis, n (%) 170 (26) 22 (26) 0.901 Lupus nephritisd, n (%) 209 (31) 31 (37) 0.311 Neuropsychiatric diseasee, n (%) 21 (3) 8 (10) 0.004 Antibody profile (ever) Anti-double-stranded DNA ab, n (%) 476 (72) 71 (85) 0.012 Anti-Smith ab, n (%) 133 (20) 15 (18) 0.210 Anti-SSA and/or SSB ab, n (%) 335 (50) 40 (48) 0.634 Low C3 and/or C4, n (%) 337 (51) 51 (61) 0.083 Anti-cardiolipin ab, n (%) 148 (22) 51 (81) <0.001 Lupus anticoagulant ab, n (%) 125 (19) 73 (87) <0.001 Anti-beta-2-glycoprotein ab, n (%) 87 (13) 33 (39) <0.001 Two or more antiphospholipid ab, n (%) 98 (15) 49 (58) <0.001 Triple positive antiphospholipid ab, n (%) 636 (5) 24 (29) <0.001 Missing antiphospholipid status, n (%) 51 (8) 0 na Medication use (ever)f Hydroxychloroquine, n (%) 591 (89) 77 (92) 0.502 Methotrexate, n (%) 148 (22) 13 (15) 0.142 Azathioprine, n (%) 233 (35) 35 (42) 0.248 Mycophenolate mofetil, n (%) 159 (24) 20 (24) 0.983 Cyclophosphamide, n (%) 106 (16) 16 (19) 0.498 Outcome parameters Follow-up yearsg, µ (SD) 8 (5) 10 (6) 0.010 Arterial or venous thromboembolic event (ever), n (%) 101 (15) 73 (87) <0.001 Arterial thromboembolic event (ever), n (%) 72 (11) 28 (33) <0.001 Venous thromboembolic event (ever), n (%) 37 (6) 54 (64) <0.001 aDefined by 2006 Sapporo classification criteria, bSLE diagnosis before age 16 years, cThe 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus, dLupus nephritis defined cThe 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus, eNeuropsychiatric disease defined by The 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus, tUse of medication six months or more, gFrom inception at SLE diagnosis to last follow-up n: number; µ: mean, SD: Standard Deviation, ab: antibody, na: not applicable

• Publisher: Lupus Foundation of America,BMJ Publishing Group LTD,BMJ Publishing Group
• Subject: Angina pectoris / Classification / Ischemia / Lupus / Oral Presentations / Population-based studies / Rheumatism / Rheumatology / Thrombocytopenia / Thromboembolism