Free 3-nitrotyrosine in exhaled breath condensates of children fails as a marker for oxidative stress in stable cystic fibrosis and asthma.
3-Nitrotyrosine (3-NT) is considered as a marker of oxidative stress, which occurs during inflammation. Since 3-NT levels in exhaled breath condensate (EBC) are very low, we applied a specific and sensitive gas chromatography-negative ion chemical ionization-mass spectrometry (GC-NICI-MS) method and high performance liquid chromatography (HPLC) with electrochemical detection for the analysis of free 3-NT in EBC. A total of 42 children (aged 5-17 years) were enrolled in this study, including children with asthma (n=12), cystic fibrosis (n=12), and healthy controls (n=18). Additionally, 14 healthy non-smoking adults (aged 18-59 years) were included. An EcoScreen system was used for the collection of EBC samples. Free 3-NT levels in EBC ranged from 0.54-6.8 nM. Median (interquartile range) concentrations (nM) were similar in all groups: 1.46 (0.97-2.49) in healthy adults, 2.51 (1.22-3.51) in healthy children, 1.46 (0.88-2.02) in children with asthma, and 1.97 (1.37-2.35) in CF children, respectively (p=0.24, Kruskall-Walis test). No difference was found between the children with airway disease and age-matched healthy controls. In healthy subjects, there was no effect of age on 3-NT concentrations. HPLC analyses provided similar concentration ranges for EBC 3-NT when compared with GC-NICI-MS. Our study has clearly demonstrated that free 3-NT in EBC fails as a marker for oxidative stress in children with stable CF and asthma.
Celio
Silva
S
Division of Respiratory Medicine, University Children's Hospital Zurich, Steinwiesstrasse 75, CH-8032 Zurich, Switzerland.
Troxler
Heinz
H
Durka
Silke S
SS
Chládek
Jaroslav
J
Wildhaber
Johannes H
JH
Sennhauser
Felix H
FH
Heizmann
Claus W
CW
Moeller
Alexander
A
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism*; D001944:Breath Tests; D002648:Child; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000378:metabolism*; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D015415:Biomarkers; C002744:3-nitrotyrosine; D014443:Tyrosine