Janus kinase 2 mutation and venous thrombosis in Egyptian patients with Philadelphia negative chronic myeloproliferative neoplasms

Abstract

Background
The Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders, in which the Janus kinase 2 (JAK2) V617F mutation is detected in more than 95% of polycythemia vera (PV) patients and in ~50% of patients with essential thrombocytosis and primary myelofibrosis (PMF). Thrombosis is acknowledged as a primary cause of morbidity and mortality in PV and essential thrombocytosis. Multifactorial pathophysiology underlies thrombosis in MPN. We aimed to study the presence and risk of thrombosis in Egyptian patients with Philadelphia negative myeloproliferative neoplasms and its relation to JAK2 V617F mutation status.


Patients and methods
Forty-seven patients with Philadelphia negative chronic myeloproliferative disorders were included in this case study. All patients were assessed for JAK2 mutation and the presence of thrombosis by abdomino-pelvic ultrasonography, duplex assessment of deep veins of the abdomen and veins of both lower limbs, computed tomography pulmonary angiography, computed tomography brain, and electrocardiogram (ECG).


Results
Thrombosis was reported in 16 (34%) cases of our patients, the main site of thrombosis among participants was deep venous thrombosis (DVT) 25%. Positive JAK2 V617F mutation was found among 38 participants (group-I) constituting (80.9%) of the studied group; 14 cases of them (group A) showed thrombosis (36.8%), while 24 cases of them (group B) showed no thrombosis in any screened site (63.2%). On the other hand, negative JAK2 V617F gene mutation (group-II) was found in 9 (19.1%) cases constituting of the studied group; two of them (group C) showed thrombosis (22.2%), while remaining 7 cases (group D) showed no thrombosis (77.8%) with no statistically significant difference found between JAK2 V617F positive and JAK2 V617F negative groups regarding the presence of thrombosis (P value=0.416). Comparison between JAK2 V617F positive and negative groups with complete blood count indices was found to be statistically significant only with total leucocytic count (TLC) level (P value=0.001), while found to be not statistically significant with hemoglobin, hematocrit (HCT), and platelet (PLT) (P value=0.481, 0.768, 0.103, respectively). No statistical significance was found when comparing the thrombosis positive and negative groups with TLC, hemoglobin, HCT, and PLT (P value=0.080, 0.163, 0.481, 0.668, respectively).


Conclusion
Despite the increased occurrence of thrombosis in the JAK2 V617F positive Philadelphia negative chronic myeloproliferative neoplasms, we could not find a significant correlation when compared with JAK2 V617F negative group.