Despite the important role of Galectin-9 (Gal-9) in inflammation and angiogenesis, only a few studies on Galectin-9 expression have been performed in rheumatoid arthritis (RA) patients. The present study aimed to identify the concentration of Galectin-9 in plasma, its expression in peripheral blood T cell subsets in RA patients, and the association between Galectin-9 and vascular endothelial growth factor (VEGF) in RA.
One hundred and five active RA patients and 52 age- and sex-matched healthy controls (HCs) were enrolled in the study. Gal-9, vascular endothelial growth factor (VEGF), and tumour necrosis factor (TNF)-α level in plasma were determined by ELISA. The intracellular positive expression rates and medium fluorescence intensity (MFI) of Gal-9 and VEGF in T cell subsets, were examined by flow cytometry.
Plasma Gal-9, TNF-α, and VEGF levels were higher in the RA group than in the HCs group. The plasma Gal-9 level positively correlated with Gal-9 expression in the total lymphocyte and CD3+ T cell, CRP, SDAI, and CDAI of RA patients. The Gal-9 expressions in the cytoplasm of CD4+ T, CD8+ T, Treg, and DNT cells positively correlated with plasma TNF-α levels in RA patients. The Gal-9 expressions in CD4+ T and CD8+ T subsets also positively correlated with plasma VEGF levels. The plasma VEGF levels and VEGF expressions in CD4+ T, CD8+ T, and Treg subsets positively correlated with SDAI and CRP in RA patients.
Gal-9 can be a potential biomarker for RA disease activity. Gal-9 is probably associated with angiogenesis processing in RA.