Background: C-X-C motif chemokine 13 (CXCL13), a key chemokine driving the formation of lymphoid follicles within the inflamed synovium, is one of the most promising biomarkers recently identified in the field of chronic arthritis, because of its association with active synovitis (Bechman et al. BMC Rheumatology 2020) and poor prognosis in rheumatoid arthritis (RA) (Bugatti et al. Rheumatology 2014). We have recently demonstrated its levels are higher in seronegative RA than in psoriatic arthritis, suggesting its possible value in the differential diagnosis of these two chronic inflammatory arthritis (Piantoni et al. EULAR abstract 2022). Recently, higher CXCL13 levels were found in patients with systemic lupus erythematosus (SLE), even if an association with arthritis was not demonstrated (Ribeiro Sa et al. Lupus 2018).

Objectives: The aim of this study is to evaluate CXCL13 levels in our cohort of SLE patients with a clinical history of arthritis in comparison with RA patients and healthy controls (HC).

Methods: Cross sectional analysis of patients with SLE and arthritis [n:80; male/female=2/78; median age (25°-75° percentile)=26 (19-33) years; SLEDAI score=4 (2-6)] and with RA [n:143; male/female=30/113; age=62 (50-70) years; CRP-DAS28=2.1 (1.5-2.8)] was performed. 100 sex and age-matched healthy controls (HC) were also enrolled. CXCL13 serum levels were assessed through commercial ELISA test (R&D).

Results: CXCL13 serum levels were higher in all the subgroups of patients [SLE: 93 (42-169) pg/mL, p<0.01; RA: 77 (53-108) pg/mL, p<0.01] than in HC (22 (18-34) pg/mL). No difference was found between SLE and RA (p=0.38). No correlations were found between CXCL13 serum levels and diseases activity indices, SLEDAI 2K for SLE (r=0.18;p=0.07) and CRP-DAS28 for RA (r=0.06;p=0.60). Among SLE patients, when comparing patient based on their clinical manifestations, other than arthritis, the subgroup of those with history of lupus nephritis (LN) tended to have higher levels than the others (119 (53-232) vs 79 (32-144); p=0.06).

Conclusion: These results demonstrated the potential value of CXCL13 as a biomarker in the field of chronic arthritis. In SLE, not so many data are available regarding its potential clinical significance. Further studies are needed to better define the correlation with a specific SLE clinical domain. The finding of high levels in patients with an history of LN confirmed the results of previous research (Zeng Y et al. Clin Exp Med 2021). CXCL13 may induce B-cell infiltration into the kidneys via its receptor CXCR5 and enhances albuminuria and organ damage (Moreth K et al. J Clin Invest 2010).

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.