Beishuizen A, de Bruijn M A, Pongers-Willemse M J, Verhoeven M A, van Wering E R, Hählen K, Breit T M, de Bruin-Versteeg S, Hooijkaas H, van Dongen J J
Department of Immunology, University Hospital Rotterdam/Erasmus University Rotterdam, The Netherlands.
Leukemia. 1997 Dec;11(12):2200-7. doi: 10.1038/sj.leu.2400904.
Virtually all immunoglobulin kappa (IGK) gene deletions are mediated via rearrangements of the so-called kappa deleting element (Kde). Kde rearrangements occur either to Vkappa gene segments (Vkappa-Kde rearrangements) or to the heptamer recombination signal sequence in the Jkappa-Ckappa intron. Kde rearrangements were analyzed by the polymerase chain reaction (PCR) and heteroduplex analysis in 130 B-lineage leukemias: 63 precursor-B-acute lymphoblastic leukemias (ALL) and 67 chronic B cell leukemias. To obtain detailed information about Kde rearrangements, we sequenced 109 of the 189 detected junctional regions. Vkappa gene family usage in the Vkappa-Kde rearrangements in our series of B-lineage leukemias was comparable to Vkappa gene family usage in functional Vkappa-Jkappa rearrangements in normal and malignant mature B cells, except for a higher frequency of VkappaII family usage in precursor-B-ALL. Junctional region sequencing of the Kde rearrangements in precursor-B-ALL revealed a mean insertion of 4.7 nucleotides and a mean deletion of 9.5 nucleotides, resulting in an extensive junctional diversity, whereas in chronic B cell leukemias the insertion (1.9) and deletion (6.0) were significantly lower. The relatively extensive junctional diversity of the Kde rearrangements in precursor-B-ALL allowed us to design leukemia/patient-specific oligonucleotide probes, which were proven to be useful for detection of minimal residual disease (MRD) with sensitivities of 10(-4) to 10(-5). Kde rearrangements occur in approximately 50% of precursor-B-ALL cases and are likely to remain stable during the disease course, because Kde rearrangements are assumed to be 'end-stage' rearrangements, which cannot easily be replaced by continuing rearrangement processes. These findings indicate that junctional regions of Kde rearrangements in precursor-B-ALL represent new valuable patient-specific PCR targets for detection of MRD.
几乎所有免疫球蛋白κ（IGK）基因缺失都是通过所谓的κ缺失元件（Kde）重排介导的。Kde重排发生在Vκ基因片段（Vκ-Kde重排）或Jκ-Cκ内含子中的七聚体重组信号序列上。采用聚合酶链反应（PCR）和异源双链分析对130例B系白血病进行Kde重排分析：63例前体B淋巴细胞白血病（ALL）和67例慢性B细胞白血病。为获取有关Kde重排的详细信息，我们对189个检测到的连接区域中的109个进行了测序。在我们的B系白血病系列中，Vκ-Kde重排中的Vκ基因家族使用情况与正常和恶性成熟B细胞中功能性Vκ-Jκ重排中的Vκ基因家族使用情况相当，只是前体B-ALL中VκII家族使用频率较高。前体B-ALL中Kde重排的连接区域测序显示平均插入4.7个核苷酸，平均缺失9.5个核苷酸，导致广泛的连接多样性，而在慢性B细胞白血病中插入（1.9）和缺失（6.0）明显更低。前体B-ALL中Kde重排相对广泛的连接多样性使我们能够设计白血病/患者特异性寡核苷酸探针，经证实这些探针可用于检测微小残留病（MRD），灵敏度为10^(-4)至10^(-5)。Kde重排发生在约50%的前体B-ALL病例中，并且在疾病过程中可能保持稳定，因为Kde重排被认为是“终末期”重排，不容易被持续的重排过程所取代。这些发现表明，前体B-ALL中Kde重排的连接区域代表了用于检测MRD的新的有价值的患者特异性PCR靶点。
