B-cell progenitors (hematogones) are markedly decreased or completely absent in the bone marrows of myelodysplastic syndromes (MDS), and the finding is considered as an important feature in MDS flow cytometry immunophenotyping. We studied CD34+ hematogones as a proportion of total CD34+ cells in 160 treatment naïve low grade primary MDS patients, consecutively collected over a two-year period. While confirming that the median CD34 + hematogones was significantly decreased (1.08%, 0%, to 67.86%), we observed variably preserved CD34 + hematogones in some MDS patients. Using a 5% cutoff, a total of 46 (29%) MDS patients had ≥5% CD34 + hematogones, significantly overrepresented by MDS with ring sideroblasts (RS) (MDS-RS) (18/40, 45%, vs. 28/120, 23%, P = 0.015). While we did not observe unique features among MDS-RS, mutations were noticeably absent in a significant number of MDS without RS (37% vs. 14%, P = 0.013), including TP53 mutations (0% vs.16.5%, P = 0.021) if ≥5% CD34 + hematogones were present. Although the follow up was short (18.5 months, 0 to 151.0), a better overall survival was observed in MDS with ≥5% CD34 + hematogones, either as a group (P = 0.008) or among patients with no RS (P = 0.028). In multivariate analysis, reduced hematogones remained to be significant hazard (P = 0.015). In summary, preserved CD34 + hematogones (≥5%) are seen in over a quarter of primary low-grade MDS and these cases are overrepresented by MDS with RS or MDS with no detectable mutations. The finding is new, and this phenomenon may in part attribute to preservation of B-cell differentiation of CD34+ progenitors, and it is associated with a better prognosis in low grade MDS patients. © 2019 International Clinical Cytometry Society.

中文翻译：

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保留了CD34 + B细胞前体（CD34 +血细胞激素）的低级骨髓增生异常综合征。

在骨髓增生异常综合症（MDS）的骨髓中，B细胞祖细胞（七边形）显着减少或完全不存在，这一发现被认为是MDS流式细胞仪免疫表型的重要特征。我们研究了160名未接受过治疗的低级原发性MDS患者的CD34 +血细胞激素在总CD34 +细胞中的比例，该研究在两年期间连续收集。在确认中位数CD34 +血红素显着降低（1.08％，0％，至67.86％）的同时，我们观察到一些MDS患者中CD34 +血红素的保存不同。使用5％的截断值，总共46（29％）名MDS患者的CD34 +血细胞激素≥5％，显着超过了带有环铁粒母细胞（RS）（MDS-RS）的MDS（18/40，45％，vs 28） / 120，23％，P = 0.015）。虽然我们没有观察到MDS-RS的独特功能，如果存在≥34％CD34 +血红素，则大量无RS的MDS中明显没有突变（37％比14％，P = 0.013），包括TP53突变（0％比16.5％，P = 0.021）。尽管随访时间很短（18.5个月，从0到151.0），但作为一组（P = 0.008）或无RS患者（P = 0.028），CD34 +血红素≥5％的MDS总体生存率更高。 ）。在多变量分析中，血红素降低仍然是重大危险（P = 0.015）。总之，在超过四分之一的原发性低级MDS中发现了CD34 +血细胞激素（≥5％），这些病例被具有RS或MDS且无可检测突变的MDS所代表。这一发现是新发现，这一现象可能部分归因于保留了CD34 +祖细胞的B细胞分化，在低级MDS患者中，它与更好的预后相关。©2019国际临床细胞计量学会。