[Expression and Significance of PD-1, TIM-3 and VISTA on T Cell of Acute Myeloid Leukemia Patients].

Objective: To study the expression of multiple negative costimulatory molecules on peripheral blood T cells in patients with acute myeloid leukemia (AML) and its affection on prognosis.

Methods: The peripheral blood samples from patients with newly diagnosed AML, complete remission (CR), and no-remission (NR) were collected, the expression levels PD-1、VISTA and TIM-3 in CD4 and CD8 T cells were detected by flow cytometry , and the clinical data of patients were analyzed.

Results: The expression levels of PD-1、VISTA and TIM-3 of CD4 and CD8 T cells in the newly diagnosed AML patients were significantly higher than those in control group (P＜0.05). The expression levels of PD-1、TIM-3 and VISTA of CD4 and CD8 T cells in the CR group were significantly lower than those in newly diagnosed and the NR group (P＜0.05). The TIM-3 expression level positively correlated with VISTA expression level of CD4 and CD8 T cells in newly diagnosed AML patients (r=0.85 and 0.73). The VISTA and PD-1 expression level of CD4 T cells in newly diagnosed AML, NR after first induction chemotherapy and high risk patients significantly increased (P＜0.05), the TIM-3 expression level of CD8 T cells in high risk group significantly increased (P＜0.05), and the VISTA expression level of CD8 T cells in CBFβ-MYH11 mutation-positive group significantly decreased (P＜0.05).

Conclusion: The expression of PD-1、TIM-3 and VISTA in AML peripheral blood T cells may be involved in the immune escape of AML and can be the targets of treatment for acute myeloid leukemia patients.