DETECTION OF MINIMAL RESIDUAL LEUKEMIA IN CHILDREN

尽管儿童急性淋巴细胞白血病的治愈率有所提高 (所有)，25%-30%的患者最终死于他们的疾病。这个 急性髓细胞白血病(AML)的前景要糟糕得多：只有大约30%的人 儿童在化疗方案中治愈，并选择骨骼 骨髓移植要么是不可用的(因为缺乏 合适的捐献者)或价值有限(因为骨髓率高 复发，可能是由于自体移植物中残留的白血病)。早些时候 检测到低水平的残留白血病对两组都有好处 病人的数量。这将允许更及时地对检索进行调查 治疗，可能在出现多药耐药之前，因为 在临床明显复发的患者中可见，它将使 接受自体骨移植患者的复发来源有待确定 骨髓移植，是否残留疾病在骨髓植入 或经消融治疗后残留的耐药白血病。假说 这一建议的基础是许多急性白血病病例具有 免疫标记物的独特组合可用于 检测微小残留病(MRD)，从而识别患者 需要替代治疗的。要使用的检测系统能够 在10,000个正常细胞中检测1个白血病细胞，因此可以 将白血病量化在10-4水平(标准形态试验 复发需要1-5%可识别的爆炸)。在第一个具体目标中， 在五个不同的时间间隔采集T-T患者的骨髓样本 所有登记参加第三阶段临床试验的人都将接受评估 白血病特异性TDT/CD3表型。将进行类似的研究 从B系所有患者的标本上检测CD19/CD13，CD19/CD33， CD19/CDw65和CD34/CD21表型。年结果数据比较 患有和不患有MRD的儿童将以80%的力量展示其价值 这一方法可用于前瞻性识别高危患者。 巨大的患者收益(4年内200名受试者)也将使 可以直接比较我们的灵敏度和特异度 免疫学检测与聚合酶链式反应(PCR)检测结果一致， 应用于克隆性分子异常(特定目标2)。聚合酶链式反应分析 一直被认为是检测MRD的临床有用工具，但它的 相对于免疫标志物检测的有效性还没有得到证实 在一项对照的前瞻性试验中进行评估。最后，它的实用性 检测MRD的免疫学方法将在儿童AML中进行评估， 使用计划进行自体移植的患者的骨髓标本 移植(特定目标3)。

Despite advancing cure rates in childhood acute lymphoblastic leukemia (ALL), 25-30% of patients eventually succumb to their disease. The outlook is far worse in acute myeloid leukemia (AML): only about 30% of children are cured in chemotherapy programs, and the option of bone marrow transplantation is either not available (because of the lack of suitable donors) or of limited value (because of high rates of marrow relapse, likely due to residual leukemia in the autografts). Early detection of low levels of residual leukemia would benefit both groups of patients. It would permit more timely investigation of retrieval therapy, possibly before the development of multi-drug resistance, as seen in patients with clinically overt relapse, and it would allow the source of relapse to be determined in patients undergoing autologous bone marrow transplantation, whether residual disease in the marrow implant or resistant leukemia remaining after ablative treatment. The hypothesis underlying this proposal is that many cases of acute leukemia possess distinctive combinations of immunologic markers that can be used to detect minimal residual disease (MRD) and thus identify patients requiring alternative treatment. The assay system to be used is capable of detecting 1 leukemic cells among 10,000 normal cells and therefore can quantify leukemia at the 10-4 level (standard morphologic tests for relapse require 1-5% identifiable blasts). In the first specific aim, marrow samples taken at five different intervals from patients with T- ALL, enrolled in a phase III clinical trial, will be assessed for the leukemia-specific TdT/CD3 phenotype. Similar studies will be performed on specimens from B-lineage ALL patients to detect CD19/CD13, CD19/CD33, CD19/CDw65 and CD34/CD21 phenotypes. Comparison of outcome data for children with and without MRD will demonstrate with 80% power the value of this approach for prospective identification of high-risk patients. The large patient accrual (> 200 subjects over 4 years) will also make it possible to directly compare the sensitivity and specificity of our immunologic assays with those of the polymerase chain reaction (PCR), as applied to clonal molecular abnormalities (specific aim 2). PCR analysis has been advocated as a clinically useful tool for MRD detection, but its efficacy relative to that of immunologic marker detection has not been assessed in a controlled, prospective trial. Finally, the usefulness of immunologic methods for MRD detection will be estimated in childhood AML, using marrow specimens from patients scheduled to undergo autologous transplantation (specific aim 3).