BIOLOGICAL STUDIES OF PCR POSITIVITY IN CML

接受干扰素或骨髓移植治疗的CML患者可以进入 长期的细胞遗传学缓解。 令人惊讶的是，其中只有一部分 患者最终会复发。 因为慢性粒细胞白血病患者携带一种癌症- 特异性标志物-t（9; 22）导致BCR-ABL基因异常， 蛋白质--检测到极低水平的微小残留病， 现在可以使用FISH和PCR技术。 然而，在这方面， 微小残留病的临床相关性尚不清楚， 这些患者结局的异质性。 例如，骨髓 移植受者和干扰素治疗的患者可能会显示出 残留BCR-ABL阳性细胞或细胞遗传学阳性前夕， 临床复发 相反，我们也观察到PCR阴性的CML 几个月内复发的病人。 因此我们建议 对细胞遗传学缓解的CML患者进行系统分析 在接受移植、干扰素或化疗后， （在此P01中概述）以确定（i）是否存在低水平的残留疾病 通过PCR或FISH在骨髓中检测到的肿瘤是由于存在 BCR-ABL信息在能够分裂和形成集落的细胞中的作用;（ii） 如果PCR阳性菌落百分比的研究增加了与 PCR检测可以帮助确定哪些患者具有最小残留 疾病将复发;和（iii）如果BCR-ABL的差异表达， 信息和p210/BCR-ABL在造血细胞中的表达 成熟（通过细胞分离技术和通过阶段特异性的 菌落测定）存在。 这些实验将在不同的 患者类别，如PCR阳性的同种异体移植后患者 或FISH阳性并复发的人与不复发的人相比。 我们 结果将与实验结果进行比较， 间期与中期FISH，试图了解临床 不同亚组的微小残留病患者， 阐明少数Ph+细胞保留的机制 而不会复发。

CML patients treated with interferon or bone marrow transplant can enter long-term cytogenetic remissions. Surprisingly, only a portion of these patients will eventually relapse. Because CML patients carry a cancer- specific marker--the t(9;22) resulting in an aberrant BCR-ABL gene and protein--the detection of very low levels of minimal residual disease is now possible with the use of FISH and PCR-based technologies. However, the clinical relevance of minimal residual disease is unclear because of the heterogeneity of outcome in these patients. For instance, bone marrow transplant recipients and interferon-treated patients may show evidence of residual BCR-ABL- positive cells or eve of cytogenetic positivity without clinical relapse. Conversely, we have also observed a PCR-negative CML patient who relapsed within several months. We therefore propose to undertake a systematic analysis of CML patients in cytogenetic remission after treatment with the transplant, interferon, or chemotherapy programs (outlined in this P01) to determine (i) if low levels of residual disease detected by PCR or FISH in bone marrow are accounted for by the presence of BCR-ABL message in cells capable of dividing and forming colonies; (ii) if the study of the percentage of PCR-positive colonies adds relevance to the PCR assay and can help determine which patients with minimal residual disease will relapse; and (iii) if differential expression of the BCR-ABL message and p210/BCR-ABL in hematopoietic cells at different stages of maturation (obtained by cell separation techniques and by stage-specific colony assays) exists. These experiments will be performed in various categories of patients such as those after allograft who are PCR-positive or FISH-positive and relapse as opposed to those who do not relapse. Our results will be compared to those obtained from experiments with interphase vs metaphase FISH in an attempt to understand the clinically different subsets of patients with minimal residual disease and to elucidate the mechanisms by which small numbers of Ph+ cells remain without the occurrence of relapse.