Biomarkers of oxidative-stress and inflammation in exhaled breath of hospital cleaners

Abstract

Background: The inhalation of cleaning products has been associated with impaired respiratory health. This study was aimed at evaluating whether the use of products containing chlorine induces changes in biomarkers of oxidative-stress and inflammation in exhaled breath condensate (EBC) and blood. Methods: We recruited 40 cleaners and 40 healthy controls and collected spirometric parameters and levels of fractional exhaled nitric oxide (FeNO). Information on respiratory symptoms and exposure history was reported using a European-Community-Respiratory-Health-Survey questionnaire. Malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), Nitrites (NO2-), Nitrates (NO3-), pH, hydrogen peroxide (H2O2) and ammonium (NH4+) were tested in EBC. Pentraxin-3 (PTX3) and soluble type II receptor of IL-1 (sIL-1RII) were analysed both in EBC and plasma. Results: No significant differences were found in the frequency of respiratory symptoms, in spirometric and FeNO parameters between the two groups. Levels of MDA-EBC, 4-HNE-EBC, and NO3--EBC were higher, whilst pH-EBC values were lower, in cleaners compared to controls both in pre and post-exposure. PTX3 and sIL-1RII were under the detection limit in EBC. In plasma, PTX3 concentrations were higher in controls, although within normal values. MDA-EBC was directly associated with both 4-HNE-EBC and reactive NO species and vice versa. Furthermore, MDA-EBC was inversely associated with pH-EBC but had a stronger correlation with PTX3. Conclusion: Exposure to cleaning agents containing chlorine is associated with higher concentrations of oxidative stress/inflammation biomarkers in EBC. These findings support the possible usefulness of EBC for the early detection of airways damage.