Yue Yanhua, Wei Wei, Guo Yanting, Wang Fei, Dong Weimin, Liu Yue, Lin Yan, Cao Yang, Gu Weiying
Department of Hematology, The First People's Hospital of Changzhou, Changzhou, Jiangsu, China (mainland).
Am J Case Rep. 2020 Oct 6;21:e925151. doi: 10.12659/AJCR.925151.
BACKGROUND Although the V617F mutation in the Janus kinase 2 (JAK2) gene and the breakpoint cluster region-abl1 (BCR-ABL1) oncogene fusion have been considered mutually exclusive in most myeloproliferative neoplasms (MPNs), many recent studies have described patients with both. This report describes a patient with chronic myelogenous leukemia (CML) and the unusual JAK2 R795S mutation and reviews 23 additional patients with JAK2 gene mutations coexisting with myelofibrosis (MF) and CML. CASE REPORT A 50-year-old woman with MF experienced rapid disease progression 3 weeks later, accompanied by severe abdominal pain and a white blood cell count of 257.45×10⁹/l. Karyotype analysis indicated that she was 46, XY, Philadelphia (Ph) (+) and BCR-ABL1 positive. Bone marrow aspiration after 1 cycle of chemotherapy and treatment with dasatinib showed that her marrow was hypercellular, with an increased number of megakaryocytes and 48.5% myeloblasts expressing the myeloid antigens CD33, CD13, CD34, CD117, and CD71. Next-generation sequencing identified a rare JAK2 R795S mutation. She was diagnosed with CML in blast phase, and was successfully treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT). CONCLUSIONS JAK2 gene mutations, including the rare JAK2 R795S mutation, can coexist with BCR-ABL1 in patients with MPNs. The clinical course of MPN in patients with both BCR-ABL1 and JAK2 mutations may be different from that in patients with classical MPNs.
尽管在大多数骨髓增殖性肿瘤（MPN）中，Janus激酶2（JAK2）基因的V617F突变和断裂点簇集区-阿贝尔逊白血病病毒1（BCR-ABL1）致癌基因融合被认为是相互排斥的，但最近许多研究描述了同时存在这两种情况的患者。本报告描述了一名患有慢性粒细胞白血病（CML）且伴有罕见JAK2 R795S突变的患者，并回顾了另外23例同时存在JAK2基因突变与骨髓纤维化（MF）和CML的患者。病例报告：一名患有MF的50岁女性在3周后病情迅速进展，伴有严重腹痛，白细胞计数为257.45×10⁹/L。核型分析表明她为46，XY，费城染色体（Ph）（+）且BCR-ABL1阳性。化疗1个周期并使用达沙替尼治疗后进行骨髓穿刺显示，她的骨髓细胞增多，巨核细胞数量增加，48.5%的原始粒细胞表达髓系抗原CD33、CD13、CD34、CD117和CD71。二代测序鉴定出一种罕见的JAK2 R795S突变。她被诊断为急变期CML，并通过异基因造血干细胞移植（allo-HSCT）成功治疗。结论：JAK2基因突变，包括罕见的JAK2 R795S突变，可在MPN患者中与BCR-ABL1共存。同时存在BCR-ABL1和JAK2突变的MPN患者的临床病程可能与经典MPN患者不同。
