Humans ; Child ; Primary Myelofibrosis/genetics* ; Prognosis ; Mutation

OBJECTIVE: To investigate the clinical characteristics of essential thrombocytopenia (ET) patients with positive mutations including JAK2, CALR, MPL, or negative mutations. METHODS: A total of 66 newly diagnosed ET cases from January 2016 to December 2018 in Department of Hematology, Huaian No.1 People's Hospital affiliated to Nanjing Medical University were analyzed. Statistical analysis data included the patient's sex, age, symptoms, thrombosis and embolism events, spleen omegaly, platelet count (Plt), leukocyte (WBC) count, hemoglobin (Hb), fibrinogen (FIB), thrombus elastic diagram (TEG), serum potassium, blood glucose (GLU), lactate dehydrogenase (LDH), JAK2, CALR and MPL mutations, treatment options, and efficacy. RESULTS: All the patients were not MPL-positive, and divided in three groups: JAK2 mutation (46 cases, 69.7%), CALR mutation (9 cases, 13.6%) and gene negative mutation (11 cases, 16.7%) group. The average age of patients in the JAK2 mutation group was 63.2 years old, and significantly higher than that in the CALR mutation group (51.8 year) and gene negative group (50.2 year) (P＜0.05). Compared with the JAK2 mutation group and gene negative group, the CALR mutation group had lower WBC count (6.3×10/L vs 13.79×10/L) (P=0.003) (6.3×10/L vs 9.70×10/L) (P=0.009). Also the Hb level of patients in CALR mutation group was lower than the JAK2 mutation group (121.22 g/L vs 136.2 g/L) (P=0.036). However, there was higher tumor burden in the CALR mutation group, compared with the gene negative mutation group (300.11 U/L vs 227.4 U/L) (P=0. 033). There was no significant difference among the three groups, such as the Plt counts, serum potassium level, GLU level and FIB level (P＞0.05). In addition, thrombus and embolism appeared in 30.3% (20/66) cases. 18.2% (12/66) cases were complicated with hyperkalemia, which significantly correlated with Plt counts (r=0.518). TEG was performed in 34 patients, of which 41.2% (14/34) had abnormal TEG and 55.9% (19/34) were accompanied by Plt count ＞ 1 000 ×10/L, but there was no significant correlation between them (r=0.134). After routine clinical treatment, all the 66 cases achieved partial or complete hematological remission, but the disease usually repeated. Until now 4.5% (3/66) cases had been converted to myelofibrosis (MF) all with JAK2 mutation, but without advancing to acute myeloid leukemia. CONCLUSION ET patients with JAK2 mutation have higher incidence, moreover were in older age. However, the patients with CALR mutations display lower WBC count and Hb level, but higher tumor burden. In short, the multiple gene mutations of ET showed different clinical features closely relates with the prognosis, thus providing guidance for the clinical diagnosis and treatment.
Aged ; Calreticulin ; genetics ; Humans ; Janus Kinase 2 ; genetics ; Middle Aged ; Mutation ; Primary Myelofibrosis ; Thrombocythemia, Essential ; Thrombocytopenia

Objective: To assess the effect of gene mutations on the efficacy of ruxolitinib for treating myelofibrosis (MF) . Methods: We retrospectively analyzed the clinical data of 56 patients with MF treated with ruxolitinib from July 2017 to December 2020 and applied second-generation sequencing (NGS) technology to detect 127 hematologic tumor-related gene mutations. Additionally, we analyzed the relationship between mutated genes and the efficacy of ruxolitinib. Results: ①Among the 56 patients, there were 36 cases of primary bone marrow fibrosis (PMF) , 9 cases of bone marrow fibrosis (ppv-mf) after polycythemia vera, and 11 cases of bone marrow fibrosis (PET-MF) after primary thrombocytosis (ET) . ②Fifty-six patients with MF taking ruxolitinib underwent NGS, among whom, 50 (89.29%) carried driver mutations, 22 (39.29%) carried ≥3 mutations, and 29 (51.79%) carried high-risk mutations (HMR) . ③ For patients with MF carrying ≥ 3 mutations, ruxolitinib still had a better effect of improving somatic symptoms and shrinking the spleen (P=0.001, P<0.001) , but TTF and PFS were significantly shorter in patients carrying ≥ 3 mutations (P=0.007, P=0.042) . ④For patients carrying ≥ 2 HMR mutations, ruxolitinib was less effective in shrinking the spleen than in those who did not carry HMR (t= 10.471, P=0.034) , and the TTF and PFS were significantly shorter in patients carrying ≥2 HMR mutations (P<0.001, P=0.001) . ⑤Ruxolitinib had poorer effects on spleen reduction, symptom improvement, and stabilization of myelofibrosis in patients carrying additional mutations in ASXL1, EZH2, and SRSF2. Moreover, patients carrying ASXL1 and EZH2 mutations had significantly shorter TTF [ASXL1: 360 (55-1270) d vs 440 (55-1268) d, z=-3.115, P=0.002; EZH2: 327 (55-975) d vs 404 (50-1270) d, z=-3.219, P=0.001], and significantly shorter PFS compared to non-carriers [ASXL1: 457 (50-1331) d vs 574 (55-1437) d, z=-3.219, P=0.001) ; 428 (55-1331) d vs 505 (55-1437) d, z=-2.576, P=0.008]. Conclusion: The type and number of mutations carried by patients with myelofibrosis and HMR impact the efficacy of ruxolitinib.
Humans ; Mutation ; Nitriles ; Primary Myelofibrosis/genetics* ; Pyrazoles ; Pyrimidines ; Retrospective Studies ; Technology ; Transcription Factors/genetics*

OBJECTIVE: To construct a myeloproliferative neoplasms (MPN) transplanted mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation, and establish a systematic evaluation system to verify the success of model construction. METHODS: The bone marrow c-kit⁺ cells of the mice were obtained by the following steps: The mice were killed by cervical dislocation, the femur, tibia and ilium were separated, and the bone marrow cells were collected. The c-kit⁺ cells were sorted after incubation with CD117 magnetic beads. The method of constructing mouse primary mutant cells is as follows: A gene mutation vector with a GFP tag was constructed by the retroviral system, and the retroviral vector was packaged into the Platinum-E cells to obtain the virus supernatant, and then used it to infect the c-kit⁺ cells of mice. The MPN mouse model was constructed as follows: the mouse primary c-kit⁺ cells containing the mutant genes were collected after infection, and then transplanted them via the tail vein into the female recipient mice of the same species which were irradiated with a lethal dose of gamma rays (8.0 Gy). The MPN mouse model was evaluated as follows: After transplantation, the peripheral blood of the mice was regularly collected from the tail vein to perform the complete blood count test, and the size of spleen and the degree of bone marrow fibrosis were estimated. RESULTS: The mouse c-kit⁺ cells with the mutant genes were successfully obtained from the bone marrow. MPN mouse model was successfully constructed: The peripheral blood cells of the MPN-transplanted mice carried exogenous implanted GFP-positive cells, and the white blood cells (WBC), platelet (PLT) and hematocrit (HCT) were all increased; the body weight loss, and the water and food intake were reduced in the transplanted mice; further pathological analysis showed that the transplanted mice displayed splenomegaly and bone marrow fibrosis. These results suggested that the MPN mouse model was successfully constructed. According to the common and different characteristics of the three MPN mouse model, a preliminary evaluation system for judging the success of MPN mouse model construction was summarized, which mainly included the following indicators, for example, the proportion of GFP-positive cells in the peripheral blood of mice; WBC, PLT and HCT; the degree of spleen enlargement and the bone marrow fibrosis. CONCLUSION The MPN mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation is successfully established by retroviral system, which can provide an important experimental animal model for the research of MPN pathogenesis and drug-targeted therapy.
Female ; Mice ; Animals ; Primary Myelofibrosis ; Myeloproliferative Disorders/genetics* ; Bone Marrow/pathology* ; Mutation ; Disease Models, Animal ; Neoplasms ; Janus Kinase 2/genetics*

No abstract available.
Female ; Fusion Proteins, bcr-abl/*genetics ; Humans ; Male ; Middle Aged ; Mutation ; Myeloproliferative Disorders/*genetics ; Polycythemia Vera/genetics ; Primary Myelofibrosis/genetics ; Proteins/*genetics ; Thrombocythemia, Essential/genetics

Classical BCR/ABL fusion gene negative myeloproliferative neoplasms (MPN), including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF), are clonal hematopoietic malignancies sharing in common origin in a multipotential hematopoietic stem cell. The phenotypic variability of the three entities can not be elucidated by JAK2V617F mutation only. Recent discoveries indicated that JAK2V617F allele burden, other mutated genes (such as TET2, ASXL1) and inherited predisposition can play roles in the complicated pathogenesis of MPN, which are summarized in this review.
Bone Marrow Neoplasms ; genetics ; Genetic Predisposition to Disease ; Humans ; Janus Kinase 2 ; genetics ; Mutation ; Myeloproliferative Disorders ; genetics ; Polycythemia Vera ; genetics ; Primary Myelofibrosis ; genetics ; Thrombocythemia, Essential ; genetics

Humans ; Janus Kinase 2 ; antagonists & inhibitors ; genetics ; physiology ; Myeloproliferative Disorders ; diagnosis ; genetics ; Point Mutation ; Polycythemia Vera ; genetics ; Primary Myelofibrosis ; genetics ; Thrombocytopenia ; genetics

Idiopathic myelofibrosis is a type of chronic myeloproliferative disorders characterized by splenomegaly, a leukoerythroblastic blood picture, teardrop poikilocytosis, in various degrees of bone marrow fibrosis and extramedullary hematopoiesis. In this paper, the biological characters and pathogenesis of idiopathic myelofibrosis such as mutation of tyrosine kinase receptor, mutation of GABA transporter 1, JAK2 mutation and c-MPl mutation, as well as other pathogenesis related with idiopathic myelofibrosis were reviewed.
GABA Plasma Membrane Transport Proteins ; genetics ; Humans ; Janus Kinase 2 ; genetics ; Mutation ; Primary Myelofibrosis ; etiology ; genetics ; Receptor Protein-Tyrosine Kinases ; genetics ; Receptors, Thrombopoietin ; genetics

The morbidity and mortality of myeloproliferative neoplasms (MPNs) are primarily caused by arterial and venous complications, progression to myelofibrosis, and transformation to acute leukemia. However, identifying molecular-based biomarkers for risk stratification of patients with MPNs remains a challenge. We have previously shown that interferon regulatory factor-8 (IRF8) and IRF4 serve as tumor suppressors in myeloid cells. In this study, we evaluated the expression of IRF4 and IRF8 and the JAK2V617F mutant allele burden in patients with MPNs. Patients with decreased IRF4 expression were correlated with a more developed MPN phenotype in myelofibrosis (MF) and secondary AML (sAML) transformed from MPNs versus essential thrombocythemia (ET). Negative correlations between the JAK2V617F allele burden and the expression of IRF8 (P < 0.05) and IRF4 (P < 0.001) and between white blood cell (WBC) count and IRF4 expression (P < 0.05) were found in ET patients. IRF8 expression was negatively correlated with the JAK2V617F allele burden (P < 0.05) in polycythemia vera patients. Complete response (CR), partial response (PR), and no response (NR) were observed in 67.5%,10%, and 22.5% of ET patients treated with hydroxyurea (HU), respectively, in 12 months. At 3 months, patients in the CR group showed high IRF4 and IRF8 expression compared with patients in the PR and NR groups. In the 12-month therapy period, low IRF4 and IRF8 expression were independently associated with the unfavorable response to HU and high WBC count. Our data indicate that the expression of IRF4 and IRF8 was associated with the MPN phenotype, which may serve as biomarkers for the response to HU in ET.
Biomarkers ; Humans ; Hydroxyurea/therapeutic use* ; Interferon Regulatory Factors/genetics* ; Janus Kinase 2/genetics* ; Leukemia, Myeloid, Acute/genetics* ; Mutation ; Phenotype ; Primary Myelofibrosis/genetics* ; Thrombocythemia, Essential/genetics*

OBJECTIVETo compare the morphologic features of bone marrow (BM) between the prefibrotic-early primary myelofibrosis (PMF) and essential thrombocythaemia (ET).

METHODSeven cases of prefibrotic-early PMF were selected and analyzed. Based on the diagnostic standard of prefibrotic-early PMF by WHO, BM aspirate smears, trephine biopsy sections and imprints of 156 uncertain ET cases conducted simultaneously were recruited into this study, the BM morphologic features between the prefibrotic-early PMF and ET groups were analyzed. The morphological difference in 22 cases of prefibrotic-early PMF and 27 ET were compared between the JAK2V617F mutation positive and negative groups.

RESULTSOf the 156 uncertain ET cases, it was reclassified 61 prefibrotic-early PMF (34 MF-0, 27 MF-1), 12 PMF and 83 ET. The platelet count and LDH level in MF-1 group were obviously higher than that of ET group (P < 0.05). The blast percentage of BM smear in MF-1 group was also higher than that of ET group (P < 0.05). As to BM section, cases with increased nucleated cells (granulocyte), compact megakaryocytic cluster, megakaryocyte near bone trabecula, cloud-like megakaryocyte, small bare nucleus of megakaryocyte and large ball-like megakaryocyte in MF-0 and MF-1 group were significantly higher than that of ET group (all P < 0.05), cases with megakaryocytic cluster of various size in MF-1 group were significantly higher than that of MF-0 and ET groups (P < 0.05). The JAK2V617F mutation rate in prefibrotic-early PMF and ET groups were 54.5% and 48.1%, respectively. Hb level in JAK2V617F mutation positive group was obviously higher than the negative group (P < 0.05), no special change with megakaryocytic morphology was found between the positive and negative groups.

CONCLUSIONMorphology of BM section, especially megakaryocytic morphologic characteristics are the main basis in distinguishing prefibrotic-early PMF from ET. The importance of morphologic index were megakaryocytic cluster with various size, cloud-like megakaryocyte, large ball-like megakaryocyte, increased nucleated cells (granulocyte), small bare nucleus, megakaryocyte near bone trabecula and compact megakaryocytic cluster in order. JAK2V617F mutation provides no specific effect on the megakaryocytic morphology.

Aged ; Bone Marrow ; pathology ; Bone Marrow Examination ; Female ; Humans ; Janus Kinase 2 ; genetics ; Male ; Megakaryocytes ; pathology ; Middle Aged ; Primary Myelofibrosis ; genetics ; pathology ; Thrombocythemia, Essential ; genetics ; pathology