OA39 Development of a Childhood Lupus Low Disease Activity State definition: recommendations from the International Childhood Lupus Treat-to-Target Task Force
Authors: Smith Eve M D , Aggarwal Amita , Ainsworth Jenny , Al-Abadi Eslam , Avcin Tadej , Bortey Lynette , Burnham Jon , Ciurtin Coziana , Hedrich Christian M , Kamphuis Sylvia , Levy Deborah , Lewandowski Laura , Maxwell Naomi , Morand Eric , Ozen Seza , Pain Clare , Ravelli Angelo , Saad Magalhaes Claudia , Pilkington Clarissa , Schonenberg Dieneke , Scott Chris , Tullus Kjell , Beresford Michael W 
Published: April 2023

Abstract

Background/Aims
International interest in development of treat-to-target (T2T) in both childhood-onset systemic lupus erythematosus (cSLE) and adult-onset SLE (aSLE) is increasing. T2T could facilitate more effective and structured use of treatments, aggressively controlling disease activity, preventing organ damage, and improving health-related quality of life. The first step is the selection of an appropriate target. Remission is deemed the ultimate target, but may not be attainable by all. Low disease activity (LDA), based on the principle of “tolerable” disease activity on stable treatment, with low corticosteroid dosage, may be more appropriate for some patients. The aim of this study was to derive a consensus-based cSLE appropriate definition of LDA, building upon existing aSLE definitions to improve applicability to cSLE, whilst maintaining sufficient unity to ensure that future T2T studies including adolescents and adults together are possible.

Methods
The International cSLE T2T Task Force, including 18 specialists from paediatric rheumatology/nephrology, and adult rheumatology undertook a series of Delphi surveys, exploring views on aSLE LDA targets. Two virtual consensus meetings were held, utilising a modified nominal group technique to debate, modify, and vote upon topics underpinning the cSLE LDA target and its criteria. Agreement of &gt; 80% was considered consensus.

Results
The task force agreed that the LDA target should encompass cSLE as a whole and be based upon the aSLE Lupus Low Disease Activity State definition (LLDAS), with modifications to make it more applicable to cSLE (cLLDAS, all 100% agreement). A conceptual definition of cLLDAS was defined: ‘A state, which if sustained, is associated with a low likelihood of adverse outcome (considering disease activity, damage, and medication toxicity)’ (100% agreement). Five cLLDAS criteria were agreed, as detailed within Table 1. The final cLLDAS definition was endorsed by the Paediatric Rheumatology European Society (PReS) Executive Council and PReS cSLE Working Party Chair, on behalf of the Society.

Conclusion
A cSLE, age-appropriate definition of cLLDAS has been generated, preserving sufficient unity with the aSLE LLDAS definition to encourage life-course research. The development and validation of targets has been a key enabler for T2T trials, therefore this initiative represents a significant step forward for cSLE.
Disclosure
E.M.D. Smith: None. A. Aggarwal: None. J. Ainsworth: None. E. Al-Abadi: None. T. Avcin: None. L. Bortey: None. J. Burnham: None. C. Ciurtin: None. C.M. Hedrich: None. S. Kamphuis: None. D. Levy: None. L. Lewandowski: None. N. Maxwell: None. E. Morand: None. S. Ozen: None. C. Pain: None. A. Ravelli: None. C. Saad Magalhaes: None. C. Pilkington: None. D. Schonenberg: None. C. Scott: None. K. Tullus: None. M.W. Beresford: None.