Attarbaschi Andishe, Mann Georg, König Margit, Steiner Manuel, Strehl Sabine, Schreiberhuber Anita, Schneider Björn, Meyer Claus, Marschalek Rolf, Borkhardt Arndt, Pickl Winfried F, Lion Thomas, Gadner Helmut, Haas Oskar A, Dworzak Michael N
Department of Hematology and Oncology, St. Anna Children's Hospital, Vienna, Austria.
Clin Cancer Res. 2006 May 15;12(10):2988-94. doi: 10.1158/1078-0432.CCR-05-2861.
Mixed lineage leukemia (MLL) abnormalities occur in approximately 50% of childhood pro-B acute lymphoblastic leukemia (ALL). However, the incidence and type of MLL rearrangements have not been determined in common ALL (cALL) and CD10+ or CD10- pre-B ALL.
To address this question, we analyzed 29 patients with pro-B ALL, 11 patients with CD10- pre-B ALL, 23 pre-B, and 26 cALL patients with CD10 on 20% to 80%, as well as 136 pre-B and 143 cALL patients with CD10 > or = 80% of blasts. They were all enrolled in four Austrian ALL multicenter trials. Conventional cytogenetics were done to detect 11q23 abnormalities and in parallel the potential involvement of the MLL gene was evaluated with a split apart fluorescence in situ hybridization probe set.
We found that 15 of 29 pro-B ALL, 7 of 11 CD10- pre-B ALL, and 1 of 2 French-American-British classification L1 mature B-cell leukemia cases had a MLL rearrangement. However, no 11q23/MLL translocation was identified among the CD10+ pre-B and cALL patients. MLL-rearranged pro-B and CD10- pre-B ALL cases had similar clinical and immunophenotypic (coexpression of CDw65 and CD15) features at initial diagnosis.
The striking similarities between the two CD10- ALL subsets imply that CD10- pre-B ALL variants may represent pro-B ALL cases that maintained the propensity to rearrange and express their immunoglobulin heavy chain rather than actual pre-B ALL forms transformed at this later stage of B-cell differentiation. However, direct experimental data are needed to confirm this observation.
混合谱系白血病（MLL）异常大约出现在50%的儿童前B细胞急性淋巴细胞白血病（ALL）中。然而，MLL重排的发生率和类型在普通ALL（cALL）以及CD10+或CD10-前B细胞ALL中尚未明确。
为解决这个问题，我们分析了29例前B细胞ALL患者、11例CD10-前B细胞ALL患者、23例前B细胞以及26例CD10表达于20%至80%母细胞的cALL患者，还有136例CD10≥80%母细胞的前B细胞和143例cALL患者。他们均纳入了四项奥地利ALL多中心试验。采用传统细胞遗传学方法检测11q23异常，同时用一种分裂荧光原位杂交探针组评估MLL基因的潜在受累情况。
我们发现29例前B细胞ALL中有15例、11例CD10-前B细胞ALL中有7例以及2例法国-美国-英国分类L1成熟B细胞白血病病例中有1例存在MLL重排。然而，在CD10+前B细胞和cALL患者中未发现11q23/MLL易位。MLL重排的前B细胞和CD10-前B细胞ALL病例在初诊时具有相似的临床和免疫表型（CDw65和CD15共表达）特征。
两个CD10-ALL亚组之间的显著相似性表明，CD10-前B细胞ALL变体可能代表前B细胞ALL病例，这些病例保持了重排和表达其免疫球蛋白重链的倾向，而不是在B细胞分化后期实际转化的前B细胞ALL形式。然而，需要直接的实验数据来证实这一观察结果。
