title: Increased neutrophil oxidative burst metabolism in systemic lupus erythematosus.
abstract: BACKGROUND
  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.
  
  
  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 (ΔMFI) 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.
  
  
  CONCLUSIONS
  The present findings corroborate the important role of innate immunity in SLE and implicate neutrophils in the pathophysiology of the disease.
authors.affiliation: Division of Rheumatology, UNIFESP/EPM, São Paulo, Brazil.
authors.forename: S F
authors.initials: SF
authors.lastname: Perazzio
authors.forename: R
authors.initials: R
authors.lastname: Salomão
authors.forename: N P
authors.initials: NP
authors.lastname: Silva
authors.forename: L E C
authors.initials: LE
authors.lastname: Andrade
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005434:Flow Cytometry; D005452:Fluoresceins / Q000737:chemistry; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism*; D010084:Oxidation-Reduction; D010586:Phagocytes / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012720:Severity of Illness Index; D013211:Staphylococcus aureus / Q000378:metabolism; D055815:Young Adult
chemical_list: D005452:Fluoresceins; D017382:Reactive Oxygen Species; C029569:diacetyldichlorofluorescein