骨髓中的 CD34 CD38- 群体包括造血干/祖细胞。最近，在急性髓性白血病中，焦点已转移到针对 CD34 CD38- 白血病细胞的流式细胞术分析，因为它们在最小/可测量残留疾病检测和预后预测方面有效。然而，在不存在白血病细胞的情况下，骨髓中这些细胞的免疫表型和细胞频率仍然未知。我们旨在通过流式细胞术评估正常细胞和白血病细胞中 CD34 CD38- 细胞的详细特征。我们比较了以下组中 CD34 CD38- 部分的细胞频率和免疫表型：特发性血小板减少性紫癜和恶性淋巴瘤患者作为对照（ n = 17）、治疗后无异常原始细胞的患者（n = 35）和患有骨髓恶性肿瘤的患者（n = 86）。比较基于 CD45RA 表达的存在或不存在，CD45RA 表达是一种常用于前瞻性分离 CD34 CD38- 部分中淋巴引发的细胞群的标记物。CD34 CD38- CD45RA 细胞群在骨髓中表现出显着扩增，但没有白血病细胞 1与对照组相比，脐带血移植后一个月以及各种类型的骨髓恶性肿瘤中的结果（p<<0.01）。 CD45RA 的持续表达和 CD34 CD38- CD45RA- 群体的显着扩增仅在骨髓增生异常综合征相关疾病中观察到。与 CD34 CD38- CD45RA- 群体相比，CD34 CD38- CD45RA 群体在白血病和非白血病细胞中频繁表达各种标记物。考虑到正常造血前体细胞的性质，应仔细评估 CD34 CD38- 部分，他们的细胞频率和免疫表型，包括 CD45RA 表达模式，以提高骨髓恶性肿瘤诊断的准确性。© 2023 国际临床细胞计量学会。

The CD34+ CD38- population in bone marrow includes hematopoietic stem/progenitor cells. Recently, in acute myeloid leukemia, the focus has shifted to flow cytometry analysis targeting CD34+ CD38- leukemic cells due to their effectiveness in minimal/measurable residual disease detection and prognosis prediction. Nevertheless, the immunophenotype and cell frequency of these cells in the bone marrow, in the absence of leukemic cells, remains unknown. We aimed to evaluate detailed characteristics of CD34+ CD38- cells in both normal and leukemic cells by flow cytometry.We compared the cell frequency and immunophenotype of the CD34+ CD38- fraction in the following groups: patients with idiopathic thrombocytopenic purpura and malignant lymphoma as controls (n = 17), post-treatment patients without abnormal blasts (n = 35), and patients with myeloid malignancies (n = 86). The comparison was based on the presence or absence of CD45RA expression, a marker commonly used to prospectively isolate lymphoid-primed cell populations within the CD34+ CD38- fraction.The CD34+ CD38- CD45RA+ cell population exhibited a significant expansion in bone marrow without leukemic cells 1 month after cord blood transplantation and in various type of myeloid malignancies, compared to the control group (p < 0.01). Continuous CD45RA expression and notable expansion of the CD34+ CD38- CD45RA- population were exclusively observed in myelodysplastic syndrome-related diseases. The CD34+ CD38- CD45RA+ population displayed frequent expression of various markers in both leukemic and non-leukemic cells, in contrast to the CD34+ CD38- CD45RA- population.The CD34+ CD38- fraction should be carefully evaluated considering the nature of normal hematopoietic precursor cells, their cell frequency and immunophenotype, including CD45RA expression pattern, for improving the accuracy of myeloid malignancy diagnosis.© 2023 International Clinical Cytometry Society.