Axelrad A A, Eskinazi D, Correa P N, Amato D
Department of Anatomy, University of Toronto, Mt Sinai Hospital, Toronto, Ontario, Canada.
Blood. 2000 Nov 15;96(10):3310-21.
Hematopoietic progenitor cells in 2 myeloproliferative disorders, juvenile chronic myelomonocytic leukemia and polycythemia vera, are known to be hypersensitive to cytokines that control normal progenitor cell proliferation, differentiation, and survival in their respective granulocyte/macrophage and erythroid lineages. Because thrombopoietin controls these functions in the normal megakaryocytic lineage, we asked the question: Are megakaryocytic progenitor cells in the myeloproliferative disorder essential thrombocythemia (ET) hypersensitive to thrombopoietin? Peripheral blood mononuclear cells from patients with ET, or secondary (reactive) thrombocytosis (2 degrees T), or healthy volunteers were grown in strictly serum-free agarose culture containing interleukin 3 (IL-3) and all-trans-retinoic acid, with various concentrations of PEG-rHu megakaryocyte growth and development factor (MGDF). The concentration of cytokine at half-maximum colony number served as a measure of progenitor cell sensitivity. Hypersensitivity to PEG-rHu MGDF was found in circulating progenitors from 18 of 20 (90%) informative patients with presumptive diagnosis ET, 1 of 8 (12.5%) 2 degrees T patients, and none of the 22 healthy volunteers. Median MGDF sensitivity ratio in ET patients was approximately 53 times greater than in the controls. This hypersensitivity, which was also directed to rHu thrombopoietin, was highly specific with respect to cytokine, disease, and cell lineage. We propose that, despite their single pluripotential cell origin, the different clinicopathologic phenotypes in different chronic myeloproliferative disorders are determined by lineage-restricted hypersensitivities of hematopoietic progenitor cells to endogenous cytokines. This work emphasizes the importance of stringent serum-free conditions for revealing true sensitivities to cytokines. The findings also offer a basis for evolving a positive test for ET, a diagnosis now made essentially by exclusion.
已知在两种骨髓增殖性疾病——青少年慢性粒单核细胞白血病和真性红细胞增多症中，造血祖细胞对控制正常祖细胞在其各自粒细胞/巨噬细胞和红系谱系中增殖、分化及存活的细胞因子高度敏感。由于血小板生成素控制正常巨核细胞谱系中的这些功能，我们提出问题：骨髓增殖性疾病原发性血小板增多症（ET）中的巨核细胞祖细胞对血小板生成素是否高度敏感？来自ET患者、继发性（反应性）血小板增多症（2度T）患者或健康志愿者的外周血单个核细胞在含有白细胞介素3（IL-3）和全反式维甲酸的严格无血清琼脂糖培养体系中培养，并添加不同浓度的聚乙二醇化重组人巨核细胞生长和发育因子（MGDF）。半数最大集落数时的细胞因子浓度作为祖细胞敏感性的指标。在20例初步诊断为ET的可提供信息的患者中，有18例（90%）循环祖细胞对聚乙二醇化重组人MGDF高度敏感，8例2度T患者中有1例（12.5%）敏感，22例健康志愿者中无一例敏感。ET患者的MGDF敏感性中位数比对照组大约高53倍。这种对重组人血小板生成素也存在的高度敏感性在细胞因子、疾病和细胞谱系方面具有高度特异性。我们提出，尽管不同慢性骨髓增殖性疾病的不同临床病理表型起源于单一的多能干细胞，但却是由造血祖细胞对内源性细胞因子的谱系限制性高度敏感性所决定的。这项工作强调了严格无血清条件对于揭示对细胞因子的真正敏感性的重要性。这些发现也为发展ET的阳性检测方法提供了基础，ET目前主要通过排除法诊断。
