Low-dose interleukin-2 for the treatment of systemic lupus erythematosus: A systematic review and meta-analysis

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• Picked for Rheumatology (top studies of the week, 20 September 2026): Systematic review, low-dose IL-2 efficacy in SLE

Abstract

OBJECTIVES: Low-dose interleukin-2 (IL-2) is a rational therapy for a variety of autoimmune disorders as it leads to expansion and improved functionality of regulatory T (Treg) cells. In this study, we reviewed the clinical efficacy of IL-2 in patients diagnosed with systemic lupus erythematosus (SLE). METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched the Scopus and MEDLINE databases for clinical trials reporting standardized outcomes of clinical efficacy after treatment with low-dose IL-2 in SLE. Our primary outcome was clinical efficacy, defined as a change in the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score. Secondary endpoints included clinical and laboratory markers of disease activity and safety. We computed mean differences and 95% confidence intervals (CIs) using a random effects model. Heterogeneity was assessed by I2 and τ2 statistics. RESULTS: Of 1448 screened articles, nine were selected, including six open-label and three randomized controlled trials. In total, the trials included 584 SLE patients treated with low-dose IL-2 and 140 receiving conventional treatment or placebo. Patients treated with low-dose IL-2 exhibited significant decreases in the SLEDAI score (mean difference - 4.62 [95% CI -5.83, -3.4], I2 = 94.4%, τ2 = 3.569), corresponding to reduced anti-double-stranded DNA (anti-dsDNA) antibody titers alongside increases in complement C3 and C4, and Treg counts. Controlled studies only partially achieved statistically significant results, but displayed a consistent trend toward higher response rates and prednisone reductions in the IL-2 groups. Few, mostly minor adverse events were reported. CONCLUSION: Low-dose IL-2 therapy may offer a promising and safe approach for the treatment of SLE. However, larger controlled trials will be needed to determine the magnitude and clinical relevance of its effects.

Abstract as published, via PubMed.