High Interleukin-37 (IL-37) Expression and Increased Mucin-Domain Containing-3 (TIM-3) on Peripheral T Cells in Patients with Rheumatoid Arthritis
Lijun Song, Yunqing Wang, Yameng Sui, Jiao Sun, Dong Li, Guosheng Li, Jianwei Liu, Tianwang Li, Qiang Shu
Shenzhen Research Institute of Shandong University, Shenzhen, Guangdong, China (mainland)
Med Sci Monit 2018; 24:5660-5667
Anti-inflammatory mediators such as mucin-domain containing-3 (TIM-3) and IL-37 play an important role in the regulation of Th1-mediated immunity. This study was designed to investigate the proportions of various T cell subsets and monocytes in the peripheral blood of rheumatoid arthritis (RA) patients, as well as the level of TIM-3 on these cells and serum cytokine levels.
MATERIAL AND METHODS: We enrolled 59 RA patients and 46 age- and sex-matched healthy controls in this study. The proportion of T cells and TIM-3 expression on these T cells were determined by flow cytometry. Cytokine levels in serum were determined by ELISA.
RESULTS: Compared with the healthy controls, the proportions of CD3+CD4+ T cells and CD3+CD4+CD25+CD127low T cells in the peripheral blood were significantly higher in RA patients. However, RA patients had significantly lower proportions of CD3+CD8+ T cells and CD3+CD4-CD8- T cells. TIM-3 was highly expressed on CD3+CD4+, CD3+CD8+, CD3+CD4+CD25+CD127low, and CD3+CD4-CD8- T cells, as well as CD14+ monocytes, in RA patients. Nevertheless, no correlation between TIM-3 level and an RA disease activity score of 28 was found. The elevated serum levels of IL-6 and IL-37 were positively correlated with tumor necrosis factor-α (TNF-α).
CONCLUSIONS: Both pro-inflammatory cytokines (TNF-α and IL-6) and anti-inflammatory mediators (TIM-3 and IL-37) simultaneously contribute to the pathogenesis of RA. TIM-3 and IL-37 may be used as potential biomarkers of active RA.
Keywords: Interleukins, T-Lymphocyte Subsets, Arthritis, Rheumatoid