[Significance of Tim-3 and Its Ligand Galectin-9 in Th1/Th2 Imbalance in Patients with Multiple Myeloma]

To investigate the significance of Tim-3 and Galectin-9 in Th1/Th2 imbalance in patients with multiple myeloma (MM).

55 newly diagnosed MM patients and 20 healthy controls were included. Flow cytometry was used to detect the expression of Tim-3 on CD4⁺T cells, the proportion of Th1, Th2, Tim-3⁺Th1 and Tim-3⁺Th2 cells in peripheral blood. ELISA was used to detect the levels of cytokines IFN-γ and IL-4 in serum, and PCR was used to detect the level of Galectin-9 mRNA. Then the correlations between Galectin-9 mRNA expression and Th-cell subsets and related cytokine levels, as well as the relationship between Tim-3⁺Th1/Tim-3⁺Th2 ratio and corresponding clinical features were analyzed.

Compared with the control group, the expression of Tim-3 on CD4⁺T cells in peripheral blood of MM patients was significantly increased (P<0.05), the proportions of Tim-3⁺Th1 cells, Tim-3⁺Th2 cells and Tim-3⁺Th1/Tim-3⁺Th2 ratio in MM patients were also increased (P<0.05), while the proportion of Th1 cells and Th1/Th2 ratio in MM patients were significantly decreased (P<0.05). The level of cytokine IFN-γ and IFN-γ/IL-4 ratio in MM patients were significantly decreased (P<0.05), while the level of cytokine IL-4 was increased (P<0.05). The mRNA levels of Galectin-9 in MM patients were significantly increased (P<0.05). The levels of Galectin-9 mRNA were positively correlated with Tim-3⁺CD4⁺T cells (r=0.663), Tim-3⁺Th2 cells (r=0.492) and IL-4 (r=0.470), while negatively correlated with IFN-γ (r=-0.593). The ratios of Tim-3⁺Th1/Tim-3⁺Th2 in MM patients were positively correlated with ISS stage (r=0.511), osteolytic damage (r=0.556) and chromosome abnormality (r=0.632).

These results suggest that Tim-3 and Galectin-9 are involved in Th1/Th2 imbalance in MM patients, and the high ratio of Tim-3⁺Th1/Tim-3⁺Th2 is associated with poor clinical prognosis.