Increased plasma peroxides as a marker of oxidative stress in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

<b>Background</b>: There is evidence that myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by activation of immune, inflammatory, oxidative and nitrosative stress (IO&NS) pathways. The present study was carried out in order to examine whether ME/CFS is accompanied by increased levels of plasma peroxides and serum oxidized LDL (oxLDL) antibodies, two biomarkers of oxidative stress.<br /><br /><b>Material/Methods</b>: Blood was collected from 56 patients with ME/CFS and 37 normal volunteers. Severity of ME/CFS was measured using the Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale.<br /><br /><b>Results</b>: Plasma peroxide concentrations were significantly higher in patients with ME/CFS than in normal controls. There was a trend towards significantly higher serum oxLDL antibodies in ME/CFS than in controls. Both biomarkers contributed significantly in discriminating between patients with ME/CFS and normal controls. Plasma peroxide and serum oxLDL antibody levels were both significantly related to one of the FF symptoms.<br /><br /><b>Conclusions</b>: The results show that ME/CFS is characterized by increased oxidative stress.<br />