POS1187 EFFECTIVENESS OF RITUXIMAB IN JUVENILE ONSET SYSTEMIC LUPUS ERYTHEMATOSUS, A REAL LIFE STUDY IN ARGENTINA

Abstract

Background:

Systemic lupus erythematosus is an autoimmune disease in which B cells play a central role in its pathogenesis. Childhood onset tends to be more severe and associated with a worse prognosis compared to adult-onset. Rituximab (RTX) is a chimeric monoclonal antibody targeting the CD20 on mature B lymphocytes. Despite its widespread use in the treatment of juvenile systemic lupus erythematosus (jSLE), evidence of its effectiveness remains limited.

Objectives:

To evaluate the effectiveness of RTX in jSLE in a cohort from a tertiary care hospital in Argentina.

Methods:

This is a retrospective study with prospective data collection including patients diagnosed with jSLE based on the SLICC 2012 and/or EULAR 2019 criteria. All patients received RTX treatment between 2014 and 2024, and had a minimum follow-up of six months after the first dose. Patients were assessed at baseline (onset of RTX treatment), six months (T1) and twelve months (T2) post treatment. Disease activity was measured using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and categorized as follows: inactive disease (SLEDAI = 0), mild activity (SLEDAI = 1-5), moderate activity (SLEDAI = 6-10), high activity (SLEDAI = 11-19), and very high activity (SLEDAI >20). Additionally, corticosteroids doses were recorded. Statistics: descriptive statistics, T Student, Mac Nemar.

Results:

A total of 153 patients were analyzed, 40 received RTX and 25 met inclusion criteria. All were assessed at T1, but only 17 reached T2 at the time of the analysis. Demographic characteristics are presented in Table 1. Rituximab was prescribed according to the following involvements: haematological and neuropsychiatric, followed by renal and pulmonary. At baseline 88% patients showed moderate, high or very high disease activity, and all were receiving doses of corticosteroids 1 mg/kg/day or higher. At T1, none of the patients had high or very high disease activity with a median SLEDAI 4 (p<0,0005). By T2, all patients exhibited either mild activity or inactive disease, with a median SLEDAI 2 (p <0.0001), and were receiving a low dose oral glucocorticoid (0.5 mg/kg/day or less, p <0,0002).

Conclusion:

In this study RTX proved effectiveness treating jSLE, achieving inactive or minimal disease activity in all cases and significantly reducing corticosteroid use. Long-term studies are warranted to evaluate durability of these responses.

REFERENCES:

NIL. Table 1Demographic characteristicsN=25Female * = 22 (88)Age at diagnosis - years** = 11,3 (7,14-15,8)Time at onset of treatment - years** = 0,1 (0-6,1)Impacts *Haematological25 (100)Constitutional23 (92)Cutaneous22 (88)Musculoskeletal17 (68)Renal17 (68)Lymphoid10 (40)Neuropsychiatric10 (40)Pulmonar8 (32)Serosal3 (12)Concomitant medication*Steroids25 (100)Hydroxychloroquine24 (96)Mycophenolate19 (76)Cyclophosphamide7 (28)Others3 (13)* N(%) ** Median (range) Table 2ResultsThe indication for RTX was related to*Haematological14 (56)Neuropsychiatric4 (16)Pulmonar2 (8)Renal2 (8)Combined3 (12)Disease activityBaseline (N=25)Time 1 (N=25)Time 2 (N=17)pInactive047NSMild activity315100,0031Moderate activity7600,0238High activity10000,0007Very high activity500NS* N(%), NS no statistically significant

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.