Oxidative stress in systemic lupus erythematosus: relationship to disease activity and symptoms

Oxidative stress may play a role in the pathogenesis of systemic lupus erythematosus (SLE). We examined the hypothesis that oxidative stress was associated with indices of lupus disease activity and severity of symptoms. Urinary F2 isoprostane excretion, a validated marker of oxidative stress, was measured in 95 patients with SLE and 103 healthy controls. Outcome measures included SLEDAI and SLICC scores, the modified health assessment questionnaire, the fatigue severity scale (FSS), and visual analogue scales (VAS) for fatigue, pain and overall disease activity. F2 isoprostane excretion was compared in patients and controls, and its relationship with clinical variables in SLE examined. F2 isoprostane excretion did not differ significantly among patients with lupus (2.7 +/- 2.3 ng/mg Cr) and control subjects (2.2 +/- 1.4 ng/mg Cr) (P = 0.70). In patients with lupus, F2 isoprostane concentrations were independently associated with higher patient reported disease activity (VAS) (OR = 1.52, P = 0.01), fatigue (FSS, OR = 1.52, P = 0.03) and lower quality of life (OR = 0.73, P = 0.05), but not with objective markers or inflammation or disease activity. In conclusion, F2 isoprostane excretion is associated with patient-reported symptoms in SLE but not with measures of inflammation, SLEDAI or SLICC. Oxidative stress may contribute to debilitating symptoms such as fatigue in SLE.