Role of Reactive Oxygen Species and Lipid Peroxidation in Patients with Newly Diagnosed Hematological Malignancies

Abstract 5199

Reactive oxygen species (ROS) may play a role in ischemia, inflammation, aging, and carcinogenesis. In some studies, it was shown that the metabolism of ROS and lipid peroxidation were stimulated in solid tumors and hematological malignancies. Moreover different results for the levels of protective enzymes from ROS were reported.

In this prospective study, the role of ROS, lipid peroxidation, and protective enzymes from ROS were investigated in patients with newly diagnosed hematologic malignancies.

Fifty-one patients (33 were male and 18 female, with mean age of 64 ± 15 years) with newly diagnosed and untreated hematological malgnancies were enrolled to this study. Local ethical commity of our university approved this study. 21 of the patients were chronic lymphocytic leukemia (CLL), 18 multiple myeloma (MM) and 12 non-Hodgkin's lymphoma (NHL). 31 healthy individuals (19 were male and 12 female, with mean age of 63±11 years) were selected as control group. The exclusion criteria were diabetes mellitus, malignancy, acute and chronic infections, and chronic inflammatory diseases. 72%, 14%, and 14% of the patients with CLL were in Stage A, Stage B and Stage C, respectively. 17%, 33%, and 50% of patients with MM were in International prognostic index-1 (IPI1), IPI2, and IPI3, respectively. The types of patients with NHL were diffuse large B-cell lymphoma (92%) and mantle cell lymphoma (8%). According to Ann-Arbor staging system, 42% of the patients with NHL were at stage 1, 8% in stage 2, 8% at stage 3, and 42% at stage 4, respectively. When diagnosed, superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, total glutathione (GSH), and malondialdehyde (MDA) as the predictor of lipid peroxidation were evaluated in both patients and controls bu spectrophometrical. The results were compared with Student-t, One-way ANOVA, and Chi-square tests.

In this study, there is no difference between patient and control groups in terms of age and sex (p>0.05). When evaluated in terms of SOD, MDA, and catalase, no difference was found between control and patient groups (p>0.05). The levels of Gpx in patients with hematological malignancies were significantly lower than control group (p< 0.001). While the levels of Gpx in all patient groups were lower than control (p< 0.001 for all groups), no significant difference was determined between patient groups (p< 0.001). Total GSH levels in patients with hematological malignancies were higher than control group (p<0.001). While GSH levels were higher only in patients with CLL (p<0.05) and MM (p<0.005), there was no difference between patients with NHL and controls (p>0.05). However, the levels of GSH were not different in patient groups (p>0.05).

In conclusion, unchanged lipid peroxidation in patients with hematological malignancies may be related to decrease in Gpx and increase in GSH. This condition may be due to inhibition of lipid peroxidation by Gpx in presence of GSH and suppression of lipid peroxidation as protective mechanism of body.