AB1070 DISTINCTIVE TRAITS OF INFECTION-TRIGGERED FLARES IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: PRELIMINARY DATA FROM A MONOCENTRIC COHORT
Authors: G. A. Ramirez, C. Calabrese, G. D. Gallina, L. Moroni, E. Bozzolo, M. Matucci-Cerinic, L. Dagna
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Systemic lupus erythematosus (SLE) is a multi-organ disease characterised by generalised immune dysfunction. Patients with SLE are more susceptible to infections and higher rates of SLE flares are observed following infectious stimuli (1, 2). Little is known about the qualitative impact of infections on SLE phenotype. <h3>Objectives:</h3> To assess potential clinical differences between infection-triggered (ITF) and other SLE flares (OF). <h3>Methods:</h3> A retrospective review of prospectively collected data from &gt;300 patients with SLE was performed. Disease activity was estimated through the SLE disease activity index 2000 (SLEDAI-2K) and the British Isles Lupus Assessment Group (BILAG) 2004 index, damage with the SLE International Collaborating Clinics/American College of Rheumatology Damage index (SDI). DAS-28 was used quantitate arthritis activity. Remission was surrogated by the Lupus Low Disease Activity State (LLDAS) algorithm. Included patient records consisted in couples of consecutive visits showing progression from LLDAS fulfillment to LLDAS loss. Visit couples were divided according to the association vs non-association of recent infections requiring antimicrobial treatment and/or absence from work. Clinical, laboratory and treatment features along with patient history data were compared at inter- and intraindividual level between the two groups. Anti-double stranded DNA antibody titres (ADNA) were recorded in a 0-4 discrete scale. Data are expressed as median (interquartile range), unless otherwise specified. <h3>Results:</h3> Out of 134 visit couples from 114 patients, 38 were ITF. Viral infections were 11/38. ITF involved one or two BILAG domains in 80% of cases, the most frequent being haematological (61%), mucocutaneous (24%) musculoskeletal 34% and renal (18%) domains. Cardiopulmonary manifestations were numerically less frequent in ITF than OF (0/38 vs 9/96; p=0.060). Although no difference was found in the frequency of musculoskeletal manifestations, ITF were characterised by higher DAS-28 scores [2.6 (2.3-4.1), n=12] than OF [2.0 (1.6-2.7), n=47;p=0.024]. Accordingly, intraindividual comparisons showed higher DAS-28 scores during ITF than during OF (10/11 vs 1/11; p=0.004). Compared to OF, viral IF were associated with lower ADNA titres [0 (0-0) vs 2 (0-3);p=0.046) and a lower frequency of complement consumption (2/11 vs 52/96; p=0.029) along with higher creatinine levels [1.2 (0.8-1.3) vs 0.8 (0.7-0.9)];p=0.016]. No differences were found in flare treatment profiles between ITF and OF. <h3>Conclusion:</h3> Preliminary data from a monocentric cohort apparently indicate that ITF, especially of viral origin, are associated with distinct clinical and serological phenotypes. This evidence suggests the existence of diverging pathophysiological mechanisms sustaining SLE activity under different conditions, which might benefit for personalized treatments. <h3>REFERENCES:</h3> [1] Danza A, et al., Lupus. 2013 [2] Joo YB, et al., Scientific Reports. 2021 <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> Giuseppe Alvise Ramirez Astrazeneca (lessons), Astrazeneca, GSK (advisory boards), Astrazeneca (financial support for publication), Chiara Calabrese: None declared, Gabriele Domenico Gallina: None declared, Luca Moroni Astrazeneca (lessons), Astrazeneca, GSK (advisory boards), Astrazeneca (financial support for publication), Enrica Bozzolo: None declared, Marco Matucci-Cerinic: None declared, Lorenzo Dagna: None declared