Childhood-onset Systemic Lupus Erythematosus

Childhood-onset systemic lupus erythematosus (cSLE) is a severe chronic autoimmune disease with a high burden of major-organ involvement. Lupus nephritis (LN) affects more than half of children with SLE, and proliferative LN-including class III, IV, III+V, and IV+V disease-is associated with acute kidney injury, progression to end-stage kidney disease, and poor long-term outcomes. Glucocorticoids remain a cornerstone of induction therapy for proliferative LN. However, the optimal initial dose in children is uncertain. Although recent adult SLE and LN guidelines increasingly recommend lower-dose glucocorticoid regimens with rapid tapering, pediatric guidelines still commonly recommend high initial prednisone doses of 1.5-2.0 mg/kg/day. Adult trials and comparative observational studies suggest that lower-dose glucocorticoid regimens may preserve efficacy while reducing treatment-related toxicity. Because cumulative glucocorticoid exposure in children may impair growth, development, psychosocial well-being, and medication adherence, this trial will compare low-dose versus high-dose initial glucocorticoid regimens for induction treatment of pediatric proliferative LN. The objective is to determine whether a lower-dose regimen is non-inferior in efficacy while reducing glucocorticoid-related adverse effects and improving quality of life.

This prospective observational study aims to characterize the peripheral immune landscape of pediatric patients with childhood-onset systemic lupus erythematosus ( cSLE) who are receiving CD3×CD19 bispecific T-cell engager (BiTE) therapy under a separate, approved exploratory clinical study. The present study does not assign, modify, or influence any therapeutic interventions. Peripheral blood samples are collected longitudinally at predefined time points in parallel with routine clinical follow-up. Immune profiling is performed using multiparameter flow cytometry, with single-cell sequencing conducted in a subset of samples to further explore cellular and molecular features. Clinical data, including disease activity indices and relevant serological biomarkers, are recorded concurrently. The objective of this study is to describe immune cell dynamics and immune features associated with changes in disease activity in cSLE, and to explore potential biomarker candidates that may inform future immune-monitoring strategies and mechanistic research in this population.