To study the expression of CD200 in acute myeloid leukemia (AML) bone marrow stem cells and its clinical efficacy.

Totally 51 AML patients were divided into the high white blood cell group (18 cases) and non-high white blood cell group (33 cases) according to whether the initial white blood cell count > 100 × 10⁹/L. The 51 AML patients also were divided into the complete response group (31 cases) and the non-response group (20 cases) after the first chemotherapy, and 51 iron-deficiency anemia or megaloblastic anemia patients were selected as the control group at the same time. The expression of CD200 and Foxp3⁺/CD4⁺ before and after the first chemotherapy were detected by flow cytometry in AML patients. The levels of interleukin-17 (IL-17), IL-4 and interferon-gamma (IFN-γ) in the peripheral blood before and after chemotherapy were detected by enzyme-linked immunosorbent assay (ELISA) in AML patients and control group. The Pearson correlation was used to analyze the relationship between expression of CD200 in AML patients and IL-17, IL-4, IFN-γ and Foxp3⁺/CD4⁺ before and after chemotherapy.

The positive rate of CD200 in the high white blood cell group were much higher than those in the non-high white blood cell group [(4.8 ± 2.8)% vs. (3.7 ± 2.2)%, t = 4.961, P < 0.001], and the positive rate of CD200 in the non-response group also increased as compared with the complete response group [(4.8 ± 2.6)% vs. (3.1 ± 1.6)%, t = 5.716, P < 0.001]. In the control group, the levels of IL-17 and IFN-γ were significantly higher (t = 26.970, P < 0.001; t = 4.370, P < 0.001), the IL-4 and Foxp3⁺/CD4⁺ were much lower (t = 9.965, P < 0.001; t = 7.346, P < 0.001) than those in AML patients before chemotherapy. And statistically significant differences were observed only in the levels of IL-17 and IL-4 between the control group and AML patients after chemotherapy (t = 8.897, P < 0.001; t = 3.965, P < 0.001). Compared with the AML patients before chemotherapy, the IL-17 [(147 ± 42) ng/L vs. (332 ± 68) ng/L, t = 15.920, P < 0.001] and IFN-γ [(24 ± 8) μg/L vs. (31 ± 12) μg/L, t = 3.576, P < 0.001] increased markedly, the IL-4 [(142 ± 54) μg/L vs. (84 ± 31) μg/L, t = 6.644, P < 0.001] and Foxp3⁺/CD4⁺ [(7.5 ± 2.4)% vs. (5.2 ± 2.4)%, t = 5.330, P < 0.001] decreased obviously after chemotherapy. The expression of CD200 in AML patients was only correlated with Foxp3⁺/CD4⁺ levels after chemotherapy (r = 0.347, P = 0.012).

The espression of CD200 can affect the clinical efficacy in AML patients by suppressing the immune-related factors.