BACKGROUND Flow cytometry (FCM) is a simple, sensitive, and specific technique that can potentially determine DNA ploidy in B-cell precursor ALL (BCP-ALL) and is complementary to cytogenetics. METHODS A prospective FCM DNA ploidy analysis using FxCycle™ Violet (assay sensitivity 0.01%) was done in 125 consecutive new cases of BCP-ALL (90 cases <15 years of age) and compared with corresponding cytogenetic ploidy (karyotyping and/or FISH) data wherever available. This assay was also subsequently evaluated for detection of residual aneuploid clone in few BCP-ALL cases. RESULTS Of the total 125 BCP-ALL cases evaluated, flow ploidy analysis revealed diploidy (DI 0.96-1.05) in 44.8% (n = 56), low-hyperdiploidy (DI 1.06 to 1.15) in 13.6% (n = 17), high-hyperdiploidy (DI 1.16-1.39) in 32.8% (n = 41) and near-tetraploidy (DI ≥ 1.80) in 2.4% (n = 3) cases. The high risk sub-group of low-hypodiploidy (DI 0.70 to 0.88)/near-triploidy (DI 1.40 to 1.79) constituted 5.6% (n = 7) cases while there was only one case with haploidy (DI 0.58). Overall, high concordance of 90.4% (n = 113) was noted between the combined cytogenetics ploidy and FCM ploidy. Of the total discordant cases (n = 12), the maximum discordance was seen in the low-hyperdiploid DI subgroup (n = 10), which included seven cases with low DNA index high hyperdiploidy (LDI-HHD). FCM DNA ploidy assay was able to detect the residual clone in all six MRD positive aneuploid cases evaluated. CONCLUSIONS FxCycle™ based DNA ploidy ascertains strong correlation with cytogenetic profiles and yields complementary information that can be used by the cytogenetics laboratories or otherwise. © 2019 International Clinical Cytometry Society.

中文翻译：

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基于FxCycle™的倍性与B细胞急性淋巴细胞白血病中的细胞遗传倍性相关，能够检测非整倍性最小残留疾病克隆。

背景技术流式细胞术（FCM）是一种简单，灵敏和特异的技术，可以潜在地确定B细胞前体ALL（BCP-ALL）中的DNA倍性，并且是细胞遗传学的补充。方法使用FxCycle™紫罗兰（测定灵敏度0.01％）对连续的125例BCP-ALL新病例（90例<15岁）进行前瞻性FCM DNA倍体分析，并将其与相应的细胞遗传倍体（核型分析和/或FISH）进行比较可用数据。随后还对该方法进行了评估，以检测在少数BCP-ALL病例中残留的非整倍体克隆。结果在评估的全部125例BCP-ALL病例中，流倍体分析显示44.8％（n = 56）的二倍体（DI 0.96-1.05），13.6％（n = 17）的低超二倍体（DI 1.06至1.15）。 -超二倍体（DI 1.16-1.39）在32.8％（n = 41）和近四倍体（DI≥1.80）在2。4％（n = 3）例。低二倍体（DI 0.70至0.88）/近三倍体（DI 1.40至1.79）的高风险亚组占5.6％（n = 7）例，而单倍体（DI 0.58）仅一例。总体而言，细胞遗传学倍性和FCM倍性之间的一致性高达90.4％（n = 113）。在全部不一致病例（n = 12）中，最大的不一致发生在低二倍体DI亚组（n = 10）中，其中包括7例具有低DNA指数高双倍体（LDI-HHD）的病例。FCM DNA倍性分析能够检测所有6个MRD阳性非整倍性病例中的残留克隆。结论基于FxCycle™的DNA倍性确定了与细胞遗传学特征的强相关性，并产生了可被细胞遗传学实验室或其他机构使用的互补信息。©2019国际临床细胞计量学会。