The phenotypic effect of JAK2 mutation in BCR-ABL negative chronic myeloproliferative diseases

Background and aims: Chronic myeloproliferative neoplasia (CMPN) is a clonal disease that causes acute leukemia progression, causing hemostasis and thrombosis anomalies by increasing the number of peripheral and immature cells as a result of uncontrolled proliferation of bone marrow of one or more myeloidyroid cells. According to the World Health Organization's (WHO) 2008 classification of myeloid cancers, CMD is replaced by the term chronic myeloproliferative "cancers" (CMC). In addition, mastocytosis has been included within the CMD and chronic eosinophilic leukemia (BAL) has been implicated in CMD, provided that there is no underlying specific molecular defect (BCR-ABL1, PDGFRA, PDGFRB, or FGFR1). When compared to BCR-ABL1 negative CMD, it is considered that Polycythemia Vera (PV), Essential Thrombocytosis (ET), Primer Myelofibrosis (PMF), Chronic Neutrophilic Leukemia (CNL), Hypereosinophilic syndrome, Mast cell disease and BCR- Other non-classified CMPHs. Materials and Methods: In this study, we included 233 patients between April 2014 and June 2016 who were admitted to the Department of Hematology of Gaziantep University Medical Faculty. Of these patients, 146 were ET (62.66%), 76 were PV (32.61%), and 11 (4.72%) were PMF patients. JAK2 V617F mutation presence in peripheral blood samples of all patients was performed by RT-PCR (Real-time polymerase chain reaction) method. The data was transferred to a computer using SPSS 20.0 (Statistical Package for Social Science). The normal distribution suitability of the variables was tested by Chi-square and Skapiro Wilks test. Results: JAK2 V617F mutation was found to be positive in 77 (% 52,74) of 146 ET patients, 50 (% 65,79) of 76 PV patients and 7 (63,63%) of 11 PMF patients. In women with ET, mutation frequency in men was significantly higher in PV patients than in PMF patients. It is known that high age of diagnosis in CMPNs pose a risk in terms of complications that may develop. There was a significant difference between the mean age of patients with JAK2 V617F mutation positive and the mean age of mutation negative patients (p <0.05) In PV patients, 72% of JAK2 positive patients and 24% of JAK2 negative patients were detected while 58.44% of the JAK2 positive patients and 39.13% of the JAK2 negative patients of ET patients were found to have hepatomegaly, splenomegaly or hepatosplenomegaly (p<0,05). The organomegaly of PMF patients was found to be 85,71% indole in JAK2 positive and 100% (100%) in JAK2 negative ones (p>0,05). Vascular complications (thrombosis / emboli) were found in 29,87% of patients with JAK2 positive ET patients and 8.69% of unda vascular complications were found in JAK2 negative patients (p<0,05). Vascular complications (thrombosis / emboli) were found in 29,87% of patients with JAK2 positive ET patients and 8.69% of unda vascular complications were found in JAK2 negative patients (p<0,05). In the case of PMF, this rate was 50% for JAK2 positive and 57.14% for JAK2 negative (p>0,05). Conclusion: JAK2 positivity in CMPHs has an important role in clinical features and complication development. The rates we have found in our studies show compliance with the literature. Key words: Chronic myeloproliferative neoplasm, JAK2, bcr-abl, thrombosis, hepatosplenomegaly, cytoreductive