The Thrombotic Events in Polycythemia Vera Patients May Be Related to Increased Oxidative Stress

Abstract

Objective: This study was designed to compare the oxidative stress parameters of patients with polycythemia vera (PV) to those of healthy volunteers and to investigate the probable relationship between vascular events and parameters of oxidative status such as total oxidative status (TOS), total antioxidant status, oxidative stress index (OSI) and malondialdehyde (MDA) in PV patients. Material and Methods: Thirty-five PV patients (20 males and 15 females) and 20 healthy volunteers (11 males and 9 females) were enrolled. The oxidative status parameters of the patients were measured by spectrophotometric analyses at the time of diagnosis and at 6 months after treatment which consisted of phlebotomy and 100 mg/day acetyl salicylic acid with or without hydroxyurea for the high- and low-risk disease group, respectively. These parameters were compared both to healthy controls and to each other, in order to obtain the values before and after treatment. In addition, during diagnosis, the oxidative status parameters of patients with PV and a history of a vascular event were compared with those of patients with no history of a vascular event. Results: The TOS, OSI and MDA values were significantly higher in the patients than in the control group at the time of diagnosis. At 6 months after phlebotomy and 100 mg/day acetyl salicylic acid therapy, the TOS, OSI and MDA values were significantly lower in the patients when compared to the pretreatment values. The TOS and OSI levels were notably higher in the patients with a vascular-event history than in those without this history. Conclusion: Oxidative stress parameters were increased in PV patients.

Lentiginoses in polycythemia vera patient: Is there a role forJAK2 (V617F)mutation?

“…In view of the fact that, JAK2 activates nonreceptor tyrosine kinase (NRTK) cascade 20 and in our recent study increased ROS (reactive oxygen species; oxidative stress) levels were detected in the PV patients having JAK2 mutation, 16 we further hypothesized that JAK2 activates tyrosine kinase by increasing ROS production. Hence, this might be one of the possible pathways of lentiginosis (Fig.…”

“…PV is seen in older ages particularly under the effect of acquired somatic mutation of JAK2 (V617F) 14,15 that the latter is a diagnostic parameter of the disease. 16 JAK2 is a member of the Janus kinase family of nonreceptor protein tyrosine kinases and has an important role in the cellular development and homeostasis. 17 Though, overactivity of the JAK2, chiefly under the effect of JAK2 (V617F) mutation, is well-known in myeloproliferative neoplasms, 16,18,19 its effect in melanocytic disorders has not been elucidated yet.…”

Pathogenetic mechanisms of thrombosis in patients with myeloproliferative neoplasm

“…34,35 Numerous studies have shown a high oxidative status in patients with chronic myeloproliferative neoplasms, a situation that correlates with a higher thrombotic risk. 32,36,37 Although associations of increases in oxidative stress with MPN have been identified, association with changes in membrane fluidity and thrombocyte function remains to be investigated. 32,38 The presence of circulating micro particles plays an important role in the occurrence of thrombosis in patients with chronic myeloproliferative disorders.…”

Evaluation of oxidative stress balance in acute deep vein thrombosis

“…Oxidative stress is associated with disruption of the prooxidant and antioxidant balance [8]. It results from either overproduction of free oxygen radicals or insufficiency of antioxidant mechanisms [6].…”

“…In response to increased oxidative stress, living organisms develop an antioxidant defense against the harmful effects of free oxygen radicals. Individual measurement of all the different antioxidants is difficult due to the workload involved in the laboratory, the high costs incurred, the complex techniques required and the interaction of serum antioxidants [8].…”