Oxidative stress and lipid-derived inflammatory mediators during acute exacerbations of cystic fibrosis.
OBJECTIVE
In cystic fibrosis (CF) very few studies have assessed sputum 8-iso-PGF2alpha levels during pulmonary exacerbations as a direct measure of airway oxidative stress. The role of other lipid-derived inflammatory mediators, such as the cysteinyl leukotrienes (cys-LTs) and prostaglandin (PG)-E2, during exacerbations is also poorly defined and the effect of conventional antibiotic therapy on these components of the inflammatory process is unclear.


METHODS
Sputum 8-iso-PGF2alpha, total cys-LT and PGE2 levels were measured in 17 CF patients experiencing a pulmonary exacerbation and repeated analysis were performed in 15 of these patients after antibiotic treatment. Eight stable CF and nine healthy subjects provided control data.


RESULTS
Sputum 8-iso-PGF2alpha was significantly elevated in acute, but not stable CF patients versus healthy controls (P < 0.001). Similarly, sputum cys-LT and PGE2 levels were increased in acute compared with stable CF patients and healthy controls (P <or= 0.001). Although substantially lower than in acute patients, sputum cys-LT levels in stable patients were also significantly higher than in normal controls (P = 0.01). There were strong associations between cys-LT levels and sputum total cell counts, and blood neutrophils in acute patients (r2 = 0.53, P = 0.001 and r2 = 0.33, P < 0.05, respectively). Overall in the CF patients, FEV1% predicted was strongly and negatively correlated with sputum 8-iso-PGF2alpha (r2 = 0.34, P = 0.006), cys-LT (r2 = 0.40, P = 0.002) and PGE2 (r2 = 0.52, P < 0.001) levels. Antibiotic treatment reduced sputum total cell count (P = 0.03), but did not affect 8-iso-PGF2alpha, cys-LT or PGE2 levels.


CONCLUSIONS
CF exacerbations are characterized by increased oxidative stress and sputum concentrations of bioactive lipid mediators. Treatment does not modulate these aspects of inflammation and more targeted therapy needs further study.
Reid
David W
DW
Cardio-Respiratory Research Group, University of Tasmania Medical School, Hobart, Tasmania, Australia. d.e.c.reid@utas.edu.au
Misso
Neil
N
Aggarwal
Shashi
S
Thompson
Philip J
PJ
Walters
E Haydn
EH
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007124:Immunoenzyme Techniques; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D011379:Prognosis; D013183:Sputum / Q000166:cytology / Q000378:metabolism
D000900:Anti-Bacterial Agents; D015415:Biomarkers; D015289:Leukotrienes; C112381:cysteinyl-leukotriene; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost; D003545:Cysteine