Chemotherapy is a crucial treatment for patients with acute myeloid leukemia (AML), with bone marrow suppression as the most common toxic side effect. The development, proliferation, and differentiation of various types of blood cells are regulated by a variety of hematopoietic factors. However, it is not clear whether there is a difference in the expression level of hematopoietic factors after chemotherapy in patients with AML at different altitudes and the change pattern has not been clarified.

To investigate whether there are differences in the expression levels of hematopoietic factors in bone marrow and serum before and after chemotherapy and their changes in patients with AML at varying altitudes.

A total of 28 AML patients (non-M3 type) treated for the first time in the Department of Hematology at Qinghai Provincial People's Hospital (1 501 to 2 500 m in the middle altitude area) and the Department of Hematology of Xi-Jing Hospital, Air Force Medical University of PLA (500 to 1 500 m in low altitude area) from 2021 to 2022 were selected as the research subjects, and according to the altitude of the hospitals they visited, the AML patients were divided into the middle altitude group (13 cases) and the low altitude group (15 cases). The WHO grading criteria for acute and subacute toxicity of anticancer drugs was used to evaluate the myelosuppressive scores of the patients on days 8, 14, and 28 of chemotherapy. The expression levels of erythropoietin (EPO), FMS-like tyrosine kinase 3 ligand (Flt3-L), thrombopoietin (TPO), and interferon γ (IFN-γ) in serum and bone marrow before chemotherapy and on day 8, day 28 of chemotherapy were detected and compared by enzyme-linked immunosorbent assay.

On days 14 and 28 of chemotherapy, the myelosuppressive scores of patients in the low-altitude group were higher than those in the middle-altitude group (Z=-1.975, P=0.048; Z=-2.049, P=0.040). On day 28 of chemotherapy, the serum and bone marrow EPO expression levels in the low-altitude group were higher than those in the middle-altitude group (P<0.05), the serum EPO expression level on day 28 of chemotherapy was lower than that on day 8 of chemotherapy, and the difference was statistically significant (P<0.05). On day 28 of chemotherapy, the serum and bone marrow expression levels of Flt3-L were higher in the low-altitude group compared to the middle-altitude group (P<0.05) ; the serum Flt3-L expression levels on day 8 and day 28 of chemotherapy were higher than those before chemotherapy in both groups, the bone marrow Flt3-L expression level on day 28 of chemotherapy was higher than that before chemotherapy in both groups (P<0.05). The serum TPO expression levels in the low-altitude group were higher than those in the middle-altitude group before chemotherapy, on the day 8 day 28 of chemotherapy (P<0.05) ; the serum TPO expression level in the low-altitude group was lower than that before chemotherapy on the day 8 of chemotherapy (P<0.05) ; the bone marrow TPO expression level in the low-altitude group was higher than that in the middle-altitude group on the day 28 of chemotherapy (P<0.05) ; the expression level of bone marrow TPO in the middle-altitude group on the day 28 of chemotherapy was lower than that before chemotherapy (P<0.05). There was no significant difference in serum and bone marrow IFN-γ expression levels between and within the two groups before and after chemotherapy (P>0.05) .

The expression levels of haemopoietic factors including EPO, Flt3-L, and TPO were higher during the recovery of myelosuppression after chemotherapy in AML patients at low altitude, compared to those at middle altitude. There was no significant difference between the two groups in terms of the hematopoietic inhibitory factor IFN-γ. Myelosuppression grades and degree after chemotherapy are more severe in AML patients at middle altitude than at low altitude.

化疗是急性髓系白血病（AML）患者重要的治疗手段，最常见的毒副作用是骨髓抑制。各类血细胞的发育增殖、分化受到多种造血因子的调控，不同海拔AML患者化疗后造血因子表达水平是否存在差异及其变化规律尚未明确。

探讨不同海拔AML患者化疗前后骨髓及血清造血因子表达水平是否存在差异及其变化。

选取2021—2022年青海省人民医院血液科（中海拔地区1 501~2 500 m）及中国人民解放军空军军医大学西京医院血液科（低海拔地区500~1 500 m）首诊初治的28例AML患者（非M3型）为研究对象，根据就诊医院海拔高低将AML患者分为中海拔组（13例）和低海拔组（15例）。采用WHO抗癌药物急性及亚急性毒性反应分级标准评估患者化疗第8、14、28天骨髓抑制分度；采用酶联免疫吸附法对两组患者化疗前、化疗第8天、化疗第28天血清及骨髓促红细胞生成素（EPO）、FMS样酪氨酸激酶3配体（Flt3-L）、促血小板生成素（TPO）和干扰素γ（IFN-γ）表达水平进行检测并比较。

化疗第14、28天，低海拔组患者骨髓抑制分度均高于中海拔组（Z=-1.975，P=0.048；Z=-2.049，P=0.040）。化疗第28天，低海拔组血清及骨髓EPO表达水平高于中海拔组（P<0.05）；中海拔组化疗第28天血清EPO表达水平低于化疗第8天（P<0.05）。化疗第28天，低海拔组血清及骨髓Flt3-L表达水平均高于中海拔组（P<0.05）；两组患者化疗第8天、化疗第28天血清Flt3-L表达水平均高于化疗前，两组患者化疗第28天骨髓Flt3-L表达水平均高于化疗前（P<0.05）。化疗前、化疗第8天、化疗第28天，低海拔组血清TPO表达水平均高于中海拔组（P<0.05）；低海拔组患者化疗第8天血清TPO表达水平低于化疗前（P<0.05）；化疗第28天，低海拔组骨髓TPO表达水平高于中海拔组（P<0.05）；中海拔组化疗第28天骨髓TPO表达水平低于化疗前（P<0.05）。两组患者化疗前后血清及骨髓IFN-γ表达水平组间、组内比较，差异均无统计学意义（P>0.05）。

低海拔AML患者化疗后骨髓抑制恢复期间造血生长因子EPO、Flt3-L、TPO表达水平高于中海拔，造血抑制因子IFN-γ两组间无明显差异；中海拔AML患者化疗后骨髓抑制分度及程度较低海拔更严重。