AUTHOR=Zhang Sheng-Xiao , Chen Hao-Ran , Wang Jia , Shao Hong-Fang , Cheng Ting , Pei Ruo-Meng , Su Qin-Yi , Zhang He-Yi , Li Xiao-Feng TITLE=The efficacy and safety of short-term and low-dose IL-2 combined with tocilizumab to treat rheumatoid arthritis JOURNAL=Frontiers in Immunology VOLUME=15 YEAR=2024 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1359041 DOI=10.3389/fimmu.2024.1359041 ISSN=1664-3224 ABSTRACT=Background

Immunotherapy targeting factors related to immune imbalance has been widely employed for RA treatment. This study aimed to evaluate the efficacy and safety of low-dose interleukin (IL)-2 combined with tocilizumab (TCZ), a biologics targeting IL-6, in RA patients.

Methods

Fifty adults with active RA who met the criteria with complete clinical data were recruited, and divided into three groups: control group (n=15), IL-2 group (n=26), and IL-2+TCZ group (n=9). In addition to basic treatment, participants in the IL-2 group received IL-2 (0.5 MIU/day), while participants in the IL-2+TCZ group received IL-2 (0.5 MIU/day) along with one dose of TCZ (8 mg/kg, maximum dose: 800 mg). All subjects underwent condition assessment, laboratory indicators and safety indicators detection, and records before treatment and one week after treatment.

Results

Compared with the baseline, all three groups showed significant improvement in disease conditions, as evidenced by significantly reduced disease activity indicators. The low-dose IL-2 and combination treatment groups demonstrated a violent proliferation of Tregs, while the absolute number of Th1, Th2, and Th17 cells in the latter group showed a decreasing trend. The decrease in the Th17/Treg ratio was more pronounced in the IL-2+TCZ groups. No significant adverse reactions were observed in any of the patients.

Conclusion

Exogenous low doses of IL-2 combined TCZ were found to be safe and effective in reducing effector T cells and appropriately increasing Treg levels in RA patients with high effector T cell levels. This approach helps regulate immune homeostasis and contributes to the prevention of disease deterioration.

Clinical trial registration

https://www.chictr.org.cn/showprojEN.html?proj=13909, identifier ChiCTR-INR-16009546.