AB0009 APPLICABILITY OF 2023 ACR/EULAR ANTIPHOSPHOLIPID SYNDROME CLASSIFICATION CRITERIA IN A MONOCENTRIC COHORT OF PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS FULFILLING ENTRY CRITERIA
Authors: Z. Rahme, M. Zen, L. Iaccarino, F. Arru, C. Cruciani, I. A. Gennaio, G. Hulej, F. Vesentini, A. Doria
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> The 2023 ACR/EULAR antiphospholipid syndrome (APS) classification criteria offer a more precise clinical characterisation and a higher sensitivity profile than the previous revised Sapporo criteria. APS can be associated with other connective tissue diseases, specifically with systemic lupus erythematosus (SLE). <h3>Objectives:</h3> To evaluate the use of 2023 ACR/EULAR APS classification criteria in patients affected by SLE with a previous diagnosis of secondary APS according to Revised Sapporo Criteria for APS. <h3>Methods:</h3> A retrospective monocentric cohort study was performed. Patients affected by SLE and diagnosed with APS according to Revised Sapporo Criteria for APS and fulfilling entry criteria for 2023 ACR/EULAR APS classification criteria were included. Data regarding anti-cardiolipin antibodies (aCL) and anti-beta2 glicoprotein I (anti-B2GPI) IgG and IgM refer to serum analysis performed by ELISA assays and confirmed with two measurements 12 weeks apart. Lupus anticoagulant (LA) measurement was considered persistent if confirmed in 3 or more measurements. Clinical and serological data were collected according to items proposed by the new classification criteria. <h3>Results:</h3> 44 patients affected by SLE and previously diagnosed with APS were included, 27 (61.4%) of which females. Mean age at diagnosis was 28.7±11.3 years, mean disease duration was 25.4±8.5 years. Regarding participants' APS clinical manifestations, we observed venous thromboembolism (VTE) in 40 (90.9%) patients, 24 (54.6%) of which without a high VTE profile; eleven (25%) had arterial thrombosis, 6 of which (13.64%) without a high cardiovascular risk profile; seven (15.9%) had suspected microvascular lesions and 3 (6.8%) had pathology-proved aPL nephropathy; two (4.6%) had cardiac valve thickening and 3 (6.8%) had thrombocytopenia not likely to be related to SLE disease activity. 6 (13.6%) had obstetric manifestations, 3 (6.8%) of which had ≥3 consecutive pre-fetal/fetal death (&lt;16w) and 3 (6.8%) had preeclampsia with severe features. At the moment of APS clinical manifestations, 33 (75%) had an active SLE, 5 (11, 4%) had nephrotic syndrome and 6 (13.6%) were being treated with prednisone ≥25 mg. Regarding the serological profile, we observed positive LA in 39 cases (88.6%), in 36 (81.8%) cases LA was persistently positive. We observed moderate-high titers of aCL IgM in 14 cases (31.8%) and IgG in 28 cases (63.6) and of antiB2GPI IgM in 8 cases (18.2%) and IgG in 23 (52.3%). Mean clinical score was 4.2±2.3. Mean laboratory score was 7.8±3.1. Four (9.1%) patients did not meet the new APS classification criteria, having a clinical score &lt;3, as thethe only clinical manifestation was an episode of VTE in patients with a high risk profile for VTE. <h3>Conclusion:</h3> Almost 1 out of 10 SLE patients with a previous diagnosis of concomitant APS did not meet 2023 ACR/EULAR APS classification criteria. The latest criteria offer a more specific and sensitive patient profiling, although further studies need to be conducted to assess the applicability in secondary APS syndrome. <h3>REFERENCES:</h3> [1] Barbhaiya M, Zuily S, Naden R, et al. The 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria. Arthritis Rheumatol. 2023;75(10):1687-1702. doi:10.1002/art.42624. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>