This study investigated the relationship between body mass index (BMI) and immunological disturbances in patients with systemic lupus erythematosus (SLE). Among 34 patients analyzed, those with lower BMI more frequently presented with fever and mucocutaneous symptoms. BMI showed a negative correlation with disease activity, as measured by SLEDAI-2K scores, and was identified as an independent predictor of disease activity, regardless of anti-dsDNA antibody or complement levels. While lower BMI was also associated with reduced levels of serum IFN-alpha and IFN-gamma, further analysis confirmed that BMI had a direct effect on disease activity, independent of interferon signaling.
Immunophenotyping and transcriptomic analysis revealed that BMI primarily affected T cell subsets, particularly regulatory T cells and B cells. Notably, lower BMI was linked to decreased expression in glucose metabolism-related pathways in Th1 and effector memory CD8+ T cells, but did not significantly impact IFN signaling. These findings suggest that low BMI, or cachexia, is a systemic manifestation of active SLE and plays a role in shaping immune cell behavior and gene expression. The results underscore BMI as an important factor in understanding SLE pathogenesis and disease progression.
Reference: Teruya H, Shoda H, Itamiya T, et al. Body weight in systemic lupus erythematosus is associated with disease activity and the adaptive immune system, independent of type I IFN. Front Immunol. 2025 Feb 18;16:1503559. doi: 10.3389/fimmu.2025.1503559. PMID: 40040694; PMCID: PMC11876045.
Link: https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1503559/full
