Detection of JAK2V617F and CALR Gene Mutations by Multiplex of Patients with Myeloproliferative Neoplasms PCR-Capillary Electrophoresis / 中国实验血液学杂志

OBJECTIVE@#To evaluate the proformance of multiplex PCR and capillary electrophoresis(MPCE) in the detection of JAK2V617F and CALR mutation in myeloproliferative neoplasms(MPN).@*METHODS@#The specificity primers of JAK2617F gene mutation and the primers of CALR gene were designed at the same time. The JAK2V617F and CALR gene primers were labeled with Cy5 fluorescence, all the primers were mixed in one tube for multiplex PCR and the PCR prodcuts were analysised by capillary electrophoresis. Then detection limit and sensitivity of MPCE were evaluated, and compared with comercial diagnostic kit.@*RESULTS@#JAK2V617F and CALR gene mutations could be detect by MPCE in one PCR test. JAK2V617F mutation could be detected at 0.01 ng genomic DNA, double positive JAK2V617F and CLAR gene mutations could be detected at 0.1 ng genomic DNA, at least 0.1% JAK2V617F positive mutation could be detected. The consistency between MPCE and commercial diagnostic gene mutation kit was 100%.@*CONCLUSION@#It is developed that a new gene mutation detection method of JAK2 V617F and CLAR gene based on MPCE in our experiment and it can be used as a new reagent for molecular diagnosis of MPN patients.

Differences in Hematological and Clinical Features Between Essential Thrombocythemia Cases With JAK2- or CALR-Mutations

No abstract available.

Straightforward Identification of Masked Polycythemia Vera Based on Proposed Revision of World Health Organization Diagnostic Criteria for BCR-ABL1-Negative Myeloproliferative Neoplasms

No abstract available.

Incidence, Clinical Features, and Prognostic Impact of CALR Exon 9 Mutations in Essential Thrombocythemia and Primary Myelofibrosis: An Experience of a Single Tertiary Hospital in Korea

We evaluated the incidence, clinical characteristics, and prognostic impact of calreticulin (CALR) mutations in essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients. In all, 48 ET and 14 PMF patients were enrolled, and the presence of CALR mutations was analyzed by direct sequencing. Patients were classified into three subgroups according to Janus kinase 2 (JAK2) V617F and CALR mutation status, and their clinical features and prognosis were compared. CALR mutations were detected in 15 (24.2%) patients, and the incidence increased to 50.0% in 30 JAK2 V617F mutation-negative cases. These included 11 patients with three known mutations (c.1092_1143del [seven cases], c.1154_1155insTTGTC [three cases], and c.1102_1135del [one case]) and 4 patients with novel mutations. ET patients carrying CALR mutation were younger, had lower white blood cell counts, and experienced less thrombosis during follow-up than those carrying JAK2 V617F mutation, while both patient groups showed similar clinical features and prognosis. In ET patients without JAK2 V617F mutation, CALR mutation did not significantly affect clinical manifestation and prognosis. In conclusion, CALR mutation analysis could be a useful diagnostic tool for ET and PMF in 50% of the cases without JAK2 V617F mutations. The prognostic impact of CALR mutations needs further investigation.

JAK2 V617F, MPL, and CALR Mutations in Korean Patients with Essential Thrombocythemia and Primary Myelofibrosis

Mutations in the calreticulin gene, CALR, have recently been discovered in subsets of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). We investigated Korean patients with ET and PMF to determine the prevalence, and clinical and laboratory correlations of CALR/JAK2/MPL mutations. Among 84 ET patients, CALR mutations were detected in 23 (27.4%) and were associated with higher platelet counts (P=0.006) and lower leukocyte counts (P=0.035) than the JAK2 V617F mutation. Among 50 PMF patients, CALR mutations were detected in 11 (22.0%) and were also associated with higher platelet counts (P=0.035) and trended to a lower rate of cytogenetic abnormalities (P=0.059) than the JAK2 V617F mutation. By multivariate analysis, triple-negative status was associated with shorter overall survival (HR, 7.0; 95% CI, 1.6-31.1, P=0.01) and leukemia-free survival (HR, 6.3; 95% CI, 1.8-22.0, P=0.004) in patients with PMF. The type 1 mutation was the most common (61.1%) type among all patients with CALR mutations, and tended toward statistical predominance in PMF patients. All 3 mutations were mutually exclusive and were never detected in patients with other myeloid neoplasms showing thrombocytosis. CALR mutations characterize a distinct group of Korean ET and PMF patients. Triple-negative PMF patients in particular have an unfavorable prognosis, which supports the idea that triple-negative PMF is a molecularly high-risk disease.

Calreticulin Exon 9 Mutations in Myeloproliferative Neoplasms

BACKGROUND: Calreticulin (CALR) mutations were recently discovered in patients with myeloproliferative neoplasms (MPNs). We studied the frequency and type of CALR mutations and their hematological characteristics. METHODS: A total of 168 MPN patients (36 polycythemia vera [PV], 114 essential thrombocythemia [ET], and 18 primary myelofibrosis [PMF] cases) were included in the study. CALR mutation was analyzed by the direct sequencing method. RESULTS: CALR mutations were detected in 21.9% of ET and 16.7% of PMF patients, which accounted for 58.5% and 33.3% of ET and PMF patients without Janus kinase 2 (JAK2) or myeloproliferative leukemia virus oncogenes (MPL) mutations, respectively. A total of five types of mutation were detected, among which, L367fs*46 (53.6%) and K385fs*47 (35.7%) were found to be the most common. ET patients with CALR mutation had lower leukocyte counts and ages compared with JAK2-mutated ET patients. CONCLUSION: Genotyping for CALR could be a useful diagnostic tool for JAK2-or MPL-negative ET or PMF patients. CALR mutation may be a distinct disease group, with different hematological characteristics than that of JAK2-positive patients.

Characterization of Calreticulin Expression in Mouse Endometrium during Embryo Implantation

Calreticulin (CRT), a Ca2+-binding storage protein and chaperone in the endoplasmic reticulum, modulates cell adhesiveness and integrin-dependent Ca2+ signaling. However, the role of CRT during implantation remains poorly understood. In the present study, we characterized the expression of CRT mRNA and the protein in mouse endometria from pregnancy DI to D7. Real-Time PCR and in situ hybridization results showed that the levels of CRT mRNA in the endometria of pregnant mice were significantly higher than those of non-pregnant mice (P<0.05), and increased gradually from pregnancy DI to D4, reaching the máximum level on D4, followed by a plateau from D4 to D7. Using immunofluorescence histochemistry and western blot, changes of CRT expression in the endometria of pregnant mice were consistent with the expression of CRT mRNA. Furthermore, antisense CRT oligodeoxynucleotide was injected into the uterus horns of pregnant mice (D3) to investígate its effect on embryo implantation. The result showed that the number of implanted embryos markedly decreased in the side of uterine horns receiving antisense CRT oligodeoxynucleotide(í><0.05). These findings suggest that CRT may play an important role in embryo implantation in mice.