ABSTRACT
Objective:To investigate the expression and ratio of CD4 +CD25 +Foxp3 +regulatory T cells (Tregs) to helper T cells 17 (Th17) in the peripheral blood of children with B-cell acute lymphoblastic leukemia (B-ALL). Method:54 children with newly diagnosed B-ALL in Children′s Hospital Capital Institute of Pediatrics from February 2017 to October 2019 were selected as the research subjects, with a median age of 4.9 (3.1 to 7.4) years. These children were divided into a pre-treatment group and a post-treatment group. According to the disease outcome after treatment, they were further divided into a complete remission group (45 cases), and a relapse/refractory group (9 cases). 20 healthy children were selected as the control group. Flow cytometry (FCM) was used to detect the proportions of CD4 +CD25 +Foxp3 +Treg cells and Th17 cells. The ratio of Treg/Th17 cells was calculated. Result:Before treatment, the proportion of Treg cells in the relapse/refractory group and the complete remission group (respectively 6.11±0.48, 6.20±1.16) were higher than those in the control group (4.89±1.46) (P<0.05), and the ratio of Treg/Th17 cells in peripheral blood of children with B-ALL in relapse/refractory stage and complete remission stage (respectively 8.34±2.14, 5.91±1.92) were higher than those in the control group (3.55±1.68) (P<0.05); The ratio of Treg/Th17 cells in the relapsed/refractory group was higher than that in the complete remission group (P<0.05). After treatment, the proportion of Treg cells and ratio of Treg/Th17 cells in peripheral blood of children with B-ALL in relapse/refractory stage (respectively 6.09±0.80, 7.37±1.19) were higher than those in complete remission stage (respectively 5.25±0.87, 4.22±1.50) and control group (respectively 4.89±1.46, 3.55±1.68) (P<0.05). Compared with that before treatment, children in complete remission stage after treatment had lower proportions of Treg cells and the ratio of Treg/Th17 cells, as well as higher proportions of Th17 cells in the peripheral blood (P<0.05). There were no significant differences in the proportions of Treg cells and Treg/Th17 ratio between the pre-treatment group and the post-treatment group of children in relapse/refractory stage (P>0.05).Conclusion:In peripheral blood of children with B-ALL, there is a ratio change of Treg/Th17 cells caused by the increase of CD4 +CD25 +Foxp3 +Treg cells and the decrease of Th17 cells, which tends to be normal with the remission of the disease. Regular detection of Treg and Th17 cells helps to monitor the immune status and provide prognosis of children with B-ALL, and may provide a basis for the immunotherapy of B-ALL.