Bellomo M J
Division autonome de génétique médicale, CHUV, Lausanne.
Schweiz Med Wochenschr. 1994 Jan 11;124(1-2):26-36.
Cytogenic analysis of leukemic cells has proven to be a mandatory part of the diagnosis of malignant hemopathies. Recurring clonal cytogenetic abnormalities may be divided into those exclusively associated with myeloid disorders, those uniquely observed in lymphoid diseases, and those detected in both myeloid and lymphoid hemopathies. Several of the common defects are characteristic of specific FAB types or subtypes and are associated with specific clinico pathologic syndromes and clinical complications. Cytogenetic abnormalities have served to define relatively homogeneous subsets of malignant hemopathies which are not evident from morphological and other available markers. Cytogenetic findings have been demonstrated to be powerful indicators in predicting clinical course and outcome in patients and in guiding their management. Given the significant progress made in the treatment of malignant hemopathies, it is very important to identify parameters which may be used to predict whether patients will respond favorably to standard therapies or if they are unlikely to do so and require alternative strategies, such as bone marrow transplantation. Cytogenetic studies have also provided important insights into the understanding of malignant transformation processes. In a number of recurring chromosome translocations characteristic of leukemias and lymphomas the genes that are located at the breakpoints have been identified. Molecular analysis has revealed that alteration in expression of these genes or in the properties of the encoded proteins resulting from the rearrangements plays an integral part in malignant transformation. Studies of clonality have suggested that several chromosome abnormalities may arise in pluripotent hemopoietic stem cells, whereas others may originate in cells of more restricted lineage. The author focuses first on the implications of the karyotype in the diagnosis and the prognosis of myeloproliferative syndromes, acute leukemias and myelodysplastic syndromes, then on the interest of describing new clinical-cytogenetic associations. Finally, some of the recent results obtained in a cytogenetic study of myelodysplastic syndromes are discussed.
白血病细胞的细胞遗传学分析已被证明是恶性血液病诊断的必要组成部分。复发性克隆性细胞遗传学异常可分为仅与髓系疾病相关的异常、仅在淋巴系疾病中观察到的异常以及在髓系和淋巴系血液病中均检测到的异常。一些常见缺陷是特定FAB类型或亚型的特征，与特定的临床病理综合征和临床并发症相关。细胞遗传学异常有助于定义恶性血液病中相对同质的亚组，而这些亚组从形态学和其他可用标志物中并不明显。细胞遗传学结果已被证明是预测患者临床病程和预后以及指导治疗的有力指标。鉴于恶性血液病治疗取得的重大进展，识别可用于预测患者对标准疗法是否会有良好反应或是否不太可能有良好反应并需要替代策略（如骨髓移植）的参数非常重要。细胞遗传学研究也为理解恶性转化过程提供了重要见解。在白血病和淋巴瘤的一些复发性染色体易位中，位于断点处的基因已被确定。分子分析表明，这些基因表达的改变或重排导致的编码蛋白性质的改变在恶性转化中起着不可或缺的作用。克隆性研究表明，一些染色体异常可能发生在多能造血干细胞中，而其他异常可能起源于谱系更受限的细胞。作者首先关注核型对骨髓增殖性综合征、急性白血病和骨髓增生异常综合征诊断和预后的影响，然后关注描述新的临床-细胞遗传学关联的意义。最后，讨论了骨髓增生异常综合征细胞遗传学研究中最近获得的一些结果。
