Increased neutrophil oxidative burst metabolism in systemic lupus erythematosus

Introduction: There is increased frequency of discoid lesions (2.7%) and SLE (0.5%) in patients with chronic granulomatosus disease, but the literature is still controversial about phagocyte oxidative burst in SLE patients. Materials and methods: 300 SLE patients and 301 blood donors were evaluated for quantitation of the oxidative burst in phagocytes by flow cytometry based on the oxidation of 2,7-dichlorofluorescein-diacetate after stimuli with Staphylococcus aureus and Pseudomonas aeruginosa. Results: Neutrophils from SLE patients displayed higher basal reactive oxygen species (ROS) production than healthy controls [Mean of fluorescence intensity (MFI)=53.77 +/- 11.38 vs 15.08 +/- 2.63, p<0.001] and after stimulation with S. aureus (MFI=355.46 +/- 58.55 vs 151.92 +/- 28.25, p<0.001) or P. aeruginosa (MFI=82.53 +/- 10.1 vs 48.99 +/- 6.74, p<0.001). There was stronger neutrophil response after bacterial stimuli (Delta MFI) in SLE patients than in healthy controls (S. aureus=301.69 +/- 54.42 vs 118.38 +/- 26.03, p<0.001; P. aeruginosa=28.76 +/- 12.3 vs 15.45 +/- 5.15, p<0.001), but no difference with respect to the oxidative burst profile according to disease activity (SLEDAI >= 6) or severity (SLICC-DI >= 2). Patients with kidney involvement presented higher basal and stimulated ROS production in neutrophils. Discussion: The present findings corroborate the important role of innate immunity in SLE and implicate neutrophils in the pathophysiology of the disease. Lupus (2012) 21, 1543-1551.