Basophils are hematopoietic cells derived from myeloid progenitor cells and are found in increased numbers in some myeloid neoplasms, particularly chronic myeloid leukemia (CML). Marked basophilia is a poor prognostic indicator in CML and defines accelerated phase according to the revised 4th edition World Health Organization (WHO4R) classification and the International Consensus Classification (ICC).

Basophilia is less well-documented in the classic BCR::ABL1-negative myeloproliferative neoplasms (MPNs) essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). The clinical behavior of these BCR::ABL1-negative MPNs is heterogeneous, with varying propensity to progress to fibrotic or blast phase. Prior studies have reported that patients with primary or secondary myelofibrosis (MF) with high basophil counts have increased risk of progression to blast phase, shortened survival, and more frequent CALR mutations [1].

The significance of basophilia across ET, PV, and PMF, as well as its association with driver mutations other than the classic JAK2 V617F, CALR, and MPL, have not been previously characterized. In the current study, we examined a broad cohort of MPNs to determine associations of basophilia with clinical and molecular features and patient outcome.

嗜碱性粒细胞是源自髓系祖细胞的造血细胞，在一些髓系肿瘤中的数量增加，尤其是慢性髓系白血病 （CML）。标记性嗜碱性粒细胞增多是 CML 的不良预后指标，根据修订后的第 4 版世界卫生组织 （WHO4R） 分类和国际共识分类 （ICC） 定义加速期。

嗜碱性粒细胞增多症在经典的 BCR：：ABL1 阴性骨髓增生性肿瘤 （MPN）、原发性血小板增多症 （ET）、真性红细胞增多症 （PV） 和原发性骨髓纤维化 （PMF） 中记录较少。这些 BCR：：ABL1 阴性 MPN 的临床行为是异质性的，具有不同的进展到纤维化或急变期的倾向。既往研究报道，嗜碱性粒细胞计数高的原发性或继发性骨髓纤维化 （MF） 患者进展至急变期的风险增加，生存期缩短，CALR 突变更频繁 [1]。

嗜碱性粒细胞增多在 ET 、 PV 和 PMF 中的重要性，以及它与经典 JAK2 V617F 、 CALR 和 MPL 以外的驱动突变的相关性，以前尚未表征。在目前的研究中，我们检查了广泛的 MPN 队列，以确定嗜碱性粒细胞增多与临床和分子特征以及患者预后的关联。