Relapse is a major complication of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (SCT). The objective of our study was to evaluate chimerism monitoring on the CD3-negative mononuclear cells by RQ-PCR to predict relapse of patients allografted for AML and to compare its performance with WT1 quantification. A cohort of 100 patients undergoing allogenic SCT for AML was retrospectively analyzed in a single institution. Patients without complete chimerism, defined as less than 0.01% of recipient's DNA in CD3-negative cells, had a significantly higher risk of relapse and a lower overall survival (p < 0.001). An increase in the percentage of recipient DNA in CD3-negative cells was associated with an increased risk of relapse (p < 0.001) but not with overall survival. Comparable performances between monitoring of CD3-negative cell chimerism and WT1 expression to predict relapse was observed up to more than 90 days before hematological relapse, with sensitivity of 82% and 78%, respectively, and specificity of 100% for both approaches. Quantitative specific chimerism of the CD3-negative mononuclear fraction, enriched in blastic cells, is a new and powerful tool for monitoring measurable residual disease and could be used for AML patients without available molecular markers.

中文翻译：

---

CD3阴性单核细胞中的定量嵌合预测了造血干细胞移植后急性髓细胞性白血病患者的预后。

复发是同种异体造血干细胞移植（SCT）后急性髓细胞性白血病（AML）的主要并发症。我们研究的目的是通过RQ-PCR评估对CD3阴性单核细胞的嵌合监测，以预测同种异体移植AML患者的复发情况，并将其性能与WT1定量进行比较。在单个机构中回顾性分析了接受异基因SCT治疗AML的100名患者。没有完全嵌合体的患者（定义为CD3阴性细胞中受体DNA的不到0.01％）具有较高的复发风险和较低的总体生存率（p <0.001）。CD3阴性细胞中受体DNA百分比的增加与复发风险增加相关（p <0.001），但与整体存活率无关。在血液学复发之前的90天内，观察到CD3阴性细胞嵌合体和WT1表达的预测复发之间的可比性能，其敏感性分别为82％和78％，两种方法的特异性均为100％。富含母细胞的CD3阴性单核部分的定量特异性嵌合是监测可测量残留疾病的一种新的强大工具，可用于没有可用分子标记的AML患者。