PF685 THE RELATIONSHIP BETWEEN TOTAL ANTIOXIDANT CAPACITY AND JAK2V617F MUTATION IN ESSENTIAL THROMBOCYTHEMIA

Background:Essential thrombocythemia (ET) is a BCR‐ABL1‐negative myeloproliferative neoplasm associated in 50–60% of cases with the presence of the JAK2V617F mutation. Several studies have revealed that oxidative stress induces a growth advantage to JAK2V617F‐ positive clones, but little is known about the antioxidant status of ET patients.Essential thrombocythemia (ET) is a BCR‐ABL1‐negative myeloproliferative neoplasm associated in 50–60% of cases with the presence of the JAK2V617F mutation. Several studies have revealed that oxidative stress induces a growth advantage to JAK2V617F‐ positive clones, but little is known about the antioxidant status of ET patients.Aims:To evaluate the total antioxidant capacity (TAC) in patients with ET and to investigate if there are any differences between JAK2V617F‐positive cases and JAK2V617F‐negative ET cases in terms of TAC.Methods:We evaluated patients diagnosed with ET according to the WHO criteria (2016 revised) vs. healthy subjects (control group). Patients were classified based on age, sex and JAK2V617F mutational status. Haematological and biochemical parameters, as well as bone marrow aspirate or biopsy, were analyzed. Detection of JAK2V617F mutation was performed by RT‐PCR. TAC was measured using a multi‐detection microplate reader FLUOstar Omega (reagents from Sigma‐Aldrich). Data analysis was conducted using the student T‐test and a p‐value ≤ 0.05 was considered statistically significant. The study was approved by the Ethics Committee of the University of Medicine and Pharmacy of Craiova, Romania, approval no. 79/23.02.2017. All subjects agreed to partake in the study and signed a written informed consent.Results:The study group involved 58 ET patients (mean age 59.72 ± 14.63 years, age range 22–82): 25 males (40.32%, mean age 55.77 ± 15.80 years, age range 22–82) and 37 females (59.68%, mean age 62.14 ± 13.30 years, age range 23–81). 36 patients (62.07%) were JAK2V617F‐positive and 22 patients (37.93%) were JAK2V617F‐negative. 7 patients (12.07%) had homozygous genotype and 29 patients (50.00%) had a heterozygous genotype. TAC was decreased in patients with ET compared with healthy subjects and in JAK2V617F‐positive vs. JAK2V617F‐negative cases (p < 0.05). We found no significant differences between sexes in terms of age (men = 55.77 ± 15.80 years vs. women = 62.14 ± 13.30 years, p = 0.1116) or TAC (men = 0.50 ± 0.04 mM/L vs. women = 0.49 ± 0.06 mM/L, p = 0.3043). Also, we did not record significant differences in terms of TAC between JAK2V617F homozygous genotype vs. JAK2V617F heterozygous genotype (0.48 ± 0.05 mM/L vs. 0.49 ± 0.06 mM/L, p = 0.1686).Summary/Conclusion:In patients diagnosed with ET, TAC is decreased compared to normal individuals. Also, the decrease in TAC is more expressed in JAK2V617F‐positive cases vs. JAK2V617F‐negative cases or controls. No significant differences in terms of TAC were found between sexes or JAK2V617F homozygous vs. heterozygous genotype.