Oxidative status in treatment-naïve essential thrombocythemia: a pilot study in a single center.

Oxidative stress (OS), due to pro-oxidant species [reactive oxygen species (ROS)] excess not counterbalanced by endogenous antioxidant molecules [e.g., reduced glutathione (GSH)], is involved in the pathogenesis of human cancers, but few data are available on essential thrombocythemia (ET). This study aims to investigate OS in ET off-therapy patients. Thirty ET treatment-naïve patients were compared with 26 age-matched and gender-matched controls. Serum ROS, urinary 8-hydroxydeoxyguanosine, full blood GSH levels, and reduced/oxidized GSH ratio (GSH/GSSG) were measured. Data were adjusted for gender, age, JAK2 mutational status, smoking, dyslipidemia, or hypercholesterolemia requiring drug therapy, antiplatelet therapy, treatment with acetylsalicylic acid, high-sensitive C-reactive protein levels, and absolute monocyte count. ROS and GSH levels were increased in both patients and controls. Patients showed increased GSSG (p = 0.05), reduced GSH/GSSG ratio (p = 0.08), and similar 8-hydroxydeoxyguanosine levels when compared with controls. No differences in OS parameters were found between JAK2-positive and JAK2-negative patients. Confounding factors did not modify the results. Our study suggests an OS condition in a cohort of treatment-naïve ET patients, not associated with JAK2 mutational status or with chronic inflammation situation. GSH/GSSG ratio, altered in ET patients because of increased GSSG levels, showed the presence of higher GSH levels in ET than controls as a possible compensatory mechanism of an excess of pro-oxidant production. Copyright © 2015 John Wiley & Sons, Ltd.