Increase of novel biomarkers for oxidative stress in patients with plasma cell disorders and in multiple myeloma patients with bone lesions.

OBJECTIVES: Protein oxidation plays a key role in the pathogenesis of oncological diseases. In this study, we analyzed the oxidative stress in untreated multiple myeloma (MM) patients and in patients affected by monoclonal gammopathy of uncertain significance (MGUS). METHODS: We evaluated serum levels of advanced oxidation protein products (AOPPs), advanced glycation end products (AGEs), and protein nitrosylation in patients with monoclonal gammopathy and in control subjects. RESULTS: Serum levels of AOPPs and S-nitrosylated proteins were significantly increased in MM patients in comparison to controls and to MGUS subjects. Moreover, in MM patients the levels of AOPPs, AGEs and S-nitrosylated proteins were significantly higher in patients with bone lesions compared with those without lytic bone lesions. CONCLUSIONS: MM is closely associated with oxidative stress and further investigation might provide an insight to understand a putative causal link between oxidative stress and MM disease onset and progression or MM complications