Elevated exhalation of hydrogen peroxide and thiobarbituric acid reactive substances in patients with community acquired pneumonia.
BACKGROUND
Bacterial pneumonia involves influx of activated phagocytes into distal airways. These cells release oxidants including H2O2, that may be exhaled or induce peroxidative damage to lung tissues with formation of thiobarbituric reactive substances (TBARs).


OBJECTIVE
To determine whether concentrations of H2O2 and TBARs in exhaled breath condensate (EBC) is elevated and correlate with systemic response to pneumonia during 10 days of hospital treatment.


METHODS
The concentration of H2O2 and TBARs was measured in EBC of 43 inpatients with community acquired pneumonia (CAP) and 20 healthy never smoked subjects over 10 days and were accompanied by monitoring of WBC count, serum concentration of C-reactive protein (CRP) and peroxyl radical-trapping capacity.


RESULTS
Patients with CAP exhaled 4.6-, 3.7-, 3.9-, 3.3-times more H2O2 than healthy controls at 1st, 3rd, 5th and 10th day of treatment (P<0.05), respectively. EBC concentrations of TBARs were elevated at 1st and 3rd day. H2O2 and TBARs levels decreased along with treatment course. Correlation (P<0.05) was found between H2O2 levels and CRP and WBC count (r = 0.31) at 1st day and between TBARs and CRP at 5th (r = 0.34) and 10th day (r = 0.46). The mean H2O2 exhalation estimated over ten days of treatment correlated with pneumonic chest X-ray score (r = 0.42), CRP levels (r = 0.46) and WBC count (r = 0.33) at admission (P<0.05).


CONCLUSIONS
Pneumonia is accompanied by oxidative stress in airways that moderately correlates with intensity of systemic inflammatory response. Determination of H2O2 in EBC may be helpful for non-invasive monitoring of oxidants production during lower respiratory tract infection.
Majewska
Edyta
E
Department of Experimental and Clinical Physiology, Institute of Physiology and Biochemistry, Medical University of Lodz, Mazowiecka St. 6/8, 92-215 Lodz, Poland.
Kasielski
Marek
M
Luczynski
Rafal
R
Bartosz
Grzegorz
G
Bialasiewicz
Piotr
P
Nowak
Dariusz
D
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods; D002097:C-Reactive Protein / Q000378:metabolism; D017714:Community-Acquired Infections / Q000378:metabolism; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D018410:Pneumonia, Bacterial / Q000188:drug therapy / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism*
D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D002097:C-Reactive Protein; D006861:Hydrogen Peroxide