AB1093 RHUPUS (RS) IN AFRO-DESCENDANT POPULATION: INFLUENCE OF OVERLAPPING SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND RHEUMATOID ARTHRITIS (RA) ON CLINICAL AND BIOLOGICAL PROFILE OF SLE
Authors: L. S. Fabienne, M. Ichtertz, B. Suzon, F. Moinet, P. Numeric, C. Deligny, A. Felix
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Rhupus (RS) is a rare and understudied disease entity featuring both clinical and laboratory features of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). To date, there's no consensus regarding diagnosis and management of this overlap syndrome [1]. Martinique is a 376,480-inhabitant French West Indies island, with a population predominantly of sub-Saharan African ancestry, and one of the highest SLE prevalence in the world [2]. The University Hospital of Martinique (CHUM) is the only hospital on the island, admitting most patients with autoimmune diseases and inflammatory rheumatism. <h3>Objectives:</h3> We aimed to investigate both clinical and biological characteristics of RS in the Martinican population. <h3>Methods:</h3> Retrospective, monocentric cohort of RS patients followed at the CHUM. Patients were identified 1) prospectively by their attending rheumatologists or internists between October 2021 and December 2022 either through outpatient consultations or inpatient admissions 2) using the hospital's centralised medical and biological database. Clinical and biological data were collected retrospectively from each patient's medical record. Patients meeting the diagnostic criteria for SLE (SLICC) and RA (ACR/EULAR 2010) were included. Patients who had received anti-TNF drugs prior to the diagnosis of SLE were excluded. <h3>Results:</h3> Eighteen RS were identified. Mean age at diagnosis was 51.4 (± 5.8) years, 15/18 RS were female and 1 was a smoker. RA appeared before SLE in 44.4% of cases, and 16.6% of patients had a concomitant diagnosis of SLE and RA. Hematological involvement was the most frequent feature (83.3%), followed by acute/subacute skin rash (44.4%). Renal involvement, chronic cutaneous lupus, seritis and pulmonary involvement each accounted for 27.8% of RS. Erosions were present in 66.7% of RS. Anti-CCP, rheumatoid factor and anti-DNA each were positive in 13 patients. All patients had ever received methotrexate (MTX). At last evaluation, 47.1% of patients had discontinued MTX due to side effects or ineffectiveness. Fifteen (83.3%) patients had ever received hydroxychloroquine and 17 (94.1%) corticosteroids, 8 of them long-term. Eight RS (53%) had received biotherapy, mainly Tocilizumab (38.9%) and Rituximab (27.8%). No relapses of SLE were reported in any of the 3 patients receiving TNF inhibitors. <h3>Conclusion:</h3> This is the first study of RS in the French West Indies. Afro-descendant RS from Martinique exhibits similarities with those from European, American and Asian cohorts/series. Renal involvement appears to be less frequent, and hematological involvement more frequent in Martinican RS than in Martinican SLE. Clinical and severity profiles of Afro-descendant SLE might be attenuated when overlapping with RA. Further studies of Afro-descendant RS are needed to confirm this finding. <h3>REFERENCES:</h3> [1] Antonini et al.,Autoimmunity Reviews 2020 [2] Lewis and Jawad, Rheumatology 2017 <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>