Levels of nitric oxide oxidation products are increased in the epithelial lining fluid of children with persistent asthma.
BACKGROUND
Children with severe allergic asthma have persistent airway inflammation and oxidant stress.


OBJECTIVE
We hypothesized that children with severe allergic asthma would have increased concentrations of the nitric oxide (NO) oxidation products nitrite, nitrate, and nitrotyrosine in the proximal and distal airway epithelial lining fluid (ELF). We further hypothesized that NO oxidation products would be associated with higher exhaled NO values (fraction of exhaled nitric oxide [F(ENO)]), greater allergic sensitization, and lower pulmonary function.


METHODS
Bronchoalveolar lavage fluid was obtained from 15 children with mild-to-moderate asthma, 30 children with severe allergic asthma, 5 nonasthmatic children, and 20 nonsmoking adults. The bronchoalveolar lavage fluid was divided into proximal and distal portions and nitrite, nitrate, and nitrotyrosine values were quantified.


RESULTS
Children with mild-to-moderate and severe allergic asthma had increased concentrations of nitrite (adult control subjects, 15 +/- 3 micromol/L; pediatric control subjects, 23 +/- 4 micromol/L; subjects with mild-to-moderate asthma, 56 +/- 26 micromol/L; subjects with severe asthma, 74 +/- 18 micromol/L), nitrate (37 +/- 13 vs 145 +/- 38 vs 711 +/- 155 vs 870 +/- 168 micromol/L, respectively) and nitrotyrosine (2 +/- 1 vs 3 +/- 1 vs 9 +/- 3 vs 10 +/- 4 micromol/L, respectively) in the proximal ELF. Similar results were seen in the distal ELF, although the concentrations were significantly lower (P < .05 for each). Although univariate analyses revealed no associations between NO oxidation products and clinical features, multivariate analyses revealed F(ENO) values to be a significant predictor of NO oxidation in asthmatic children.


CONCLUSIONS
NO oxidation products are increased in the ELF of asthmatic children. The relationship between F(ENO) values and airway nitrosative stress is complicated and requires further study.
Fitzpatrick
Anne M
AM
Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA. anne.fitzpatrick@emory.edu
Brown
Lou Ann S
LA
Holguin
Fernando
F
Teague
W Gerald
WG
D000293:Adolescent; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009566:Nitrates / Q000032:analysis*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000032:analysis*; D020545:Respiratory Mucosa / Q000378:metabolism*; D013147:Spirometry; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis
D018927:Anti-Asthmatic Agents; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine