#4-43E. Restoring Immune Balance: Low-Dose IL-2 Therapy in SLE (Nat Commun, 2026)

How can we effectively manage systemic lupus erythematosus (SLE) without exacerbating the infection risks typically associated with conventional immunosuppressants? This multicenter, randomized, double-blind phase IIb trial evaluated the efficacy and safety of low-dose interleukin-2 (Ld-IL2) in 152 patients with active SLE. The study revealed that administering a specific dose of 1.0 million IU of Ld-IL2 optimally and selectively expands regulatory T cells (Tregs). This restoration of immune balance led to a significantly higher SRI-4 response rate, improved disease control, and a substantial reduction in corticosteroid dependence without increasing infection rates compared to placebo. However, when critically appraising these promising results, clinicians must consider the trial's relatively small sample size per treatment group and the lack of long-term safety and efficacy data beyond the 24-week study period. Despite these limitations, this research is highly significant for daily clinical practice; it offers a novel, targeted, and steroid-sparing strategy that safely modulates the immune system. For physicians managing SLE, this optimal 1.0 million IU dosing provides a practical, evidence-based approach to minimize the conventional steroid burden while effectively controlling autoimmune activity.

Citation: Xia Zhang, Ruiling Feng, Jing He, Zhanguo Li, et al. Low dose IL-2 therapy restores regulatory T cells in patients with systemic lupus erythematosus in a dose-dependent manner: a phase IIb trial. Nature Communications. 2026. DOI: 10.1038/s41467-026-72245-7

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