Objective: Multiple myeloma (MM) is a plasma cell malignancy comprising 15% of hematological malignancies. Many studies have assessed the relationship between free radicals and tumor progression or cancer risk. We aimed to evaluate the antioxidant activity of paraoxonase 1 (PON1), arylesterase (ARE), and 8-isoprostane in patients with stage I MM.
Materials and methods: Spectrophotometric assays of serum PON1 and ARE activities in addition to serum 8-isoprostane level were performed in 34 patients newly diagnosed with stage I MM as compared to 35 age- and sex-matched individuals who comprised the healthy control group.
Results: A significant reduction was found in the activities of PON1 and ARE (for both, P < 0.001) in the patient group. The ratio of PON1/high-density lipoprotein was significantly lower in the MM patient group than in the control group (P < 0.001), while 8-isoprostane levels compared with the control group were significantly higher (P < 0.001), observations that may indicate an increase in oxidative stress in stage I MM patients.
Conclusion: A decrease in PON1 activity and increase in 8-isoprostane serum activities in patients may indicate the importance of lipid peroxidation in MM disease. Oxidative stress and especially lipid peroxidation could reduce the antioxidant activity of PON1 and ARE in MM patients and could be considered as factors in the pathogenesis of MM disease.
Keywords: 8-isoprostane; Multiple myeloma; Oxidative stress; Paraoxonase 1.