Plasma biomarkers of oxidative stress: relationship to lung disease and inhaled nitric oxide therapy in premature infants.
OBJECTIVE
Inhaled nitric oxide treatment for ventilated premature infants improves survival without bronchopulmonary dysplasia. However, there has been no information regarding possible effects of this therapy on oxidative stress. We hypothesized that inhaled nitric oxide therapy would not influence concentrations of plasma biomarkers of oxidative stress.


METHODS
As part of the Nitric Oxide Chronic Lung Disease Trial, we collected blood samples at specified intervals from a subpopulation of 100 infants of <1250 g birth weight who received inhaled nitric oxide (20 ppm, weaned to 2 ppm) or placebo gas for 24 days. Plasma was assayed for total protein and for 3-nitrotyrosine and carbonylation by using immunoassays.


RESULTS
The demographic characteristics and primary outcome for the infants were representative of the entire group of infants who were in the Nitric Oxide Chronic Lung Disease Trial. For all infants at baseline, before receiving study gas, the concentration of total protein was inversely correlated with the respiratory severity score, and plasma carbonyl was positively correlated with severity score, supporting an association between oxidative stress and severity of lung disease. Infants who survived without bronchopulmonary dysplasia had 30% lower protein carbonylation concentrations at study entry than those who had an adverse outcome. At each of 3 time points (1-10 days) during exposure to study gas, there were no significant differences between control and treated infants for concentrations of plasma protein, 3-nitrotyrosine, and carbonylation.


CONCLUSIONS
Inhaled nitric oxide treatment for premature infants who are at risk for bronchopulmonary dysplasia does not alter plasma biomarkers of oxidative stress, which supports the safety of this therapy.
Ballard
Philip L
PL
Department of Pediatrics, University of California, San Francisco, California 94118, USA. ballardp@peds.ucsf.edu
Truog
William E
WE
Merrill
Jeffrey D
JD
Gow
Andrew
A
Posencheg
Michael
M
Golombek
Sergio G
SG
Parton
Lance A
LA
Luan
Xianqun
X
Cnaan
Avital
A
Ballard
Roberta A
RA
D000280:Administration, Inhalation; D015415:Biomarkers / Q000097:blood*; D001997:Bronchopulmonary Dysplasia / Q000517:prevention & control; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009569:Nitric Oxide / Q000008:administration & dosage*; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D011506:Proteins / Q000378:metabolism; D012127:Respiratory Distress Syndrome, Newborn / Q000097:blood / Q000401:mortality* / Q000628:therapy*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016019:Survival Analysis; D016896:Treatment Outcome; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood
D015415:Biomarkers; D011506:Proteins; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine