尽管免疫表型分析最近取得了进展，但急性髓系白血病（AML）的预后仍然主要使用年龄和遗传标记来估计。由于AML患者的遗传异质性很高，基于流式细胞术的分类和适当的生物标志物可以有效补充风险分层和治疗选择。据报道，免疫检查点蛋白 B7-H3 (CD276) 的表达增加与不良预后相关。然而，可用数据有限且异构。在这里，我们使用一种新型、专有的鼠抗 B7-H3 8H8 抗体对 77 名患者的 AML 母细胞中 B7-H3 的表达进行流式细胞术分析。我们的抗体可靠地检测到 62.3% 的 AML 患者中有大量 B7-H3 表达。根据欧洲白血病网络，B7-H3 表达在单核细胞法美英 (FAB) M5 组以及中危和低危患者中较高。使用接收器操作特征 (ROC)，我们确定了特定的荧光强度截止值 4.45，以区分 B7-H3high 和 B7-H3low 表达。高 B7-H3 表达与较短的总生存期 (OS) 和无进展生存期 (PFS) 相关。总之，我们开发了一种新型 B7-H3 抗体，作为检测 AML 中 B7-H3 表达的新工具，可能有助于促进 AML 患者的风险分层和治疗选择。

Despite recent advances in immunophenotyping, the prognosis of acute myeloid leukemia (AML) is still mainly estimated using age and genetic markers. As the genetic heterogeneity of AML patients is high, flow cytometry-based classification with appropriate biomarkers can efficiently complement risk stratification and treatment selection. An increased expression of B7-H3 (CD276), an immune checkpoint protein, has been reported and associated with poor prognosis. However, the available data are limited and heterogeneous. Here, we used a novel, proprietary murine anti-B7-H3 8H8 antibody for the flow cytometric analysis of B7-H3 expression in AML blasts from 77 patients. Our antibody reliably detected substantial B7-H3 expression in 62.3% of AML patients. B7-H3 expression was higher in the monocytic French-American-British (FAB) M5 group and in intermediate and poor risk patients according to the European Leukemia Network. Using receiver operating characteristics (ROCs), we identified a specific fluorescence intensity cut-off of 4.45 to discriminate between B7-H3high and B7-H3low expression. High B7-H3 expression was associated with shorter overall survival (OS) and progression-free survival (PFS). In conclusion, we have developed a novel B7-H3 antibody that serves as a new tool for the detection of B7-H3 expression in AML and may help to facilitate risk stratification and treatment selection in AML patients.