Terminal deoxynucleotidyl transferase (TdT) is expressed on precursor lymphoblastic neoplasms and some acute myeloid leukemia (AML) cells. The clinical impact of TdT expression on AML outcomes remains unclear. Here, we conducted a retrospective analysis to identify prognostic implications of TdT expression in AML with an intermediate-risk karyotype. Forty-eight cases of intermediate-risk AML were enrolled. TdT positivity was defined as expression on ≥ 10% of the gated cells. Of 48 cases, 12 (25%) were positive for TdT [median expression rate of TdT 0.9% (range 0–86.9%)]. No significant differences in patient characteristics or complete remission rate were observed between TdT-positive and TdT-negative cases. The probability of overall survival (OS) and event-free survival (EFS) at 1 year was not significantly different between TdT-positive and TdT-negative cases (OS: 58.3% vs. 65.2%, p = 0.32; EFS: 33.3% vs. 57.1%, p = 0.06). Relapse-free survival (RFS) probability at 1 year was significantly lower for TdT-positive than TdT-negative cases (10% vs. 71.3%, p = 0.002). Multivariate analyses revealed that TdT positivity was an independent significant adverse factor for RFS [hazard ratio: 3.309, 95% confidence interval: 1.334–8.209, p = 0.009]. Our results suggest that TdT expression is associated with increased risk of relapse in patients with intermediate-risk AML.

末端脱氧核苷酸转移酶（TdT）在前体淋巴母细胞肿瘤和一些急性髓细胞性白血病（AML）细胞上表达。TdT表达对AML结果的临床影响尚不清楚。在这里，我们进行了回顾性分析，以鉴定TdT表达在具有中等风险核型的AML中的预后意义。入选了48例中危AML患者。TdT阳性定义为在≥10％的门控细胞中表达。在48例中，有12例（25％）TdT阳性[TdT的中位表达率为0.9％（范围0-86.9％）]。在TdT阳性和TdT阴性病例之间，患者特征或完全缓解率没有显着差异。p  = 0.32；EFS：33.3％和57.1％，p  = 0.06）。TdT阳性的患者在1年时无复发生存（RFS）的可能性显着低于TdT阴性的病例（10％对71.3％，p  = 0.002）。多变量分析显示，TdT阳性是RFS的一个独立的重要不利因素[危险比：3.309，95％置信区间：1.334-8.209，p  = 0.009]。我们的结果表明，TdT表达与中危AML患者复发风险增加有关。