PURPOSE:Increased 8-isoprostane in the exhaled breath condensate (EBC) was found in studies in patients with pneumoconioses. Little is known, however, whether the concentration of markers of oxidant stress is also affected by some systemic diseases (atherosclerosis, diabetes, etc.). Another unanswered question is the locus of the origin of these markers in the respiratory tract.
METHODS:Twenty patients with pneumoconiosis were examined; five of them during two different ventilation rates. Following markers were measured both in blood and in the EBC: 8-isoprostane, malondialdehyde (MDA), 4-hydroxy-trans-2-nonenal (HNE), and leukotriene B4 (LTB4). Highly sensitive methods combining enrichment method (lyophilisation, SPE extraction) with LC-MS were used for analysis. Statistical analysis was performed by paired t-test and by QC Expert software (Trilobyte).
RESULTS:Mean level in the blood and in the EBC of 8-isoprostane was 66±10 and 75.3±8.5 pg/ml; MDA 445±76 and 67±13 ng/ml; HNE 1980±440 and 448±87 ng/ml; LTB4 18.9±2.2 and 34.5±4.7 pg/ml, respectively. During breathing frequency per minute of 18 and 25, the mean level of 8-isoprostane was 75±16 and 77±20 pg/ml; MDA 80±45 and 84±49 ng/ml; HNE 320±250 and 300±220 ng/ml; and LTB4 29.4±7.6 and 33±11 pg/ml, respectively.
CONCLUSION:No positive correlation between blood and EBC concentrations was seen in the studied markers. No significant difference was seen in the level of the markers at different breathing frequency.
CLINICAL IMPLICATIONS:Markers of oxidative stress in the EBC seem independent from the blood levels which confirms their importance for lung disorders. The results are compatible with the hypothesis, that the source of increased EBC markers is the lung parenchyma. Acknowledgement: IGA MZCR NR9338 and MSM 0001620807.
DISCLOSURE:Daniela Pelclova, None.