Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD.
University of Pennsylvania-Abramson Comprehensive Cancer Center, Philadelphia, PA.
Blood Adv. 2018 Apr 24;2(8):825-831. doi: 10.1182/bloodadvances.2018015925.
Internal tandem duplications in (ITDs) are common in acute myeloid leukemia (AML) and confer a poor prognosis. A sensitive and specific assay for the detection of minimal residual disease (MRD) in ITD mutated AML could guide therapy decisions. Existing assays for MRD in ITD AML have not been particularly useful because of limited sensitivity. We developed a sensitive and specific MRD assay for ITD mutations using next-generation sequencing. The initial validation of this assay was performed by spiking fixed amounts of mutant DNA into wild-type DNA to establish a sensitivity of detection equivalent to ≥1 ITD-containing cell in 10 000, with a minimum input of 100 000 cell equivalents of DNA. We subsequently validated the assay in bone marrow samples from patients with ITD AML in remission. Finally, we analyzed bone marrow samples from 80 patients with ITD relapsed/refractory AML participating in a trial of a novel FLT3 inhibitor, gilteritinib, and demonstrated a relationship between the mutation burden, as detected by the assay, and overall survival. This novel MRD assay is specific and 2 orders of magnitude more sensitive than currently available polymerase chain reaction- or next-generation sequencing-based ITD assays. The assay is being prospectively validated in ongoing randomized clinical trials.
（ITD）内部串联重复是急性髓系白血病（AML）中的常见现象，预后不良。一种用于检测 ITD 突变 AML 微小残留病（MRD）的敏感且特异的检测方法可以指导治疗决策。由于灵敏度有限，现有的用于 ITD AML 的 MRD 检测方法并不是特别有用。我们使用下一代测序开发了一种用于 ITD 突变的敏感且特异的 MRD 检测方法。该方法的初步验证是通过将固定量的突变 DNA 掺入野生型 DNA 中进行的，以建立检测灵敏度等效于≥10000 个细胞中含有 1 个 ITD 的细胞，最低输入量为 100000 个细胞当量的 DNA。随后，我们在缓解期的 ITD AML 患者的骨髓样本中验证了该检测方法。最后，我们分析了 80 名接受新型 FLT3 抑制剂 gilteritinib 治疗的 ITD 复发/难治性 AML 患者的骨髓样本，该检测方法显示突变负担与总体生存率之间存在相关性。与目前可用的聚合酶链反应或基于下一代测序的 ITD 检测方法相比，这种新型的 MRD 检测方法具有特异性，灵敏度高 2 个数量级。该检测方法正在前瞻性地验证中。
