Lung cancer (LC) is often diagnosed at advanced stage and as a result, survival rates are low. Recent studies describe exhaled breath and exhaled breath condensate (EBC) as a potential non-invasive method of sampling the airways for assessing inflammation of the respiratory system, and possibly for the early detection of LC. It was hypothesised that higher concentrations of markers and protein will be present in the EBC of LC patients compared to those of normal controls and healthy smokers, and may aid in assessing lung status. Methods: The gaseous phase of breath was investigated for volatile organic compound (VOC) patterns using an electronic nose (eNose) system, in addition to off-line measurements of carbon monoxide (CO) and nitric oxide (NO) levels. The aqueous phase, EBC, was collected during tidal breathing through a glass collection device cooled to 4??C by ice. Nitrite/nitrate (NOx) and pH levels were determined by a fluorescent modification of the Griess method, and silicon chip sensor pH meter, respectively. Protein levels in EBC were examined with a bicinchoninic acid (BCA) assay, silver staining and PAGE techniques, while the levels of tumour markers, CYFRA 21-1 and CEA, were quantified by enzyme-linked immunosorbent assays (ELISA). Results: The eNose machine was not able to produce characteristic VOC profiles from exhaled breath unique to each study group, while no significant difference was observed for mean NOx concentrations in the LC group when compared to other subjects (p=0.8824). Higher protein levels were found in the EBC of LC patient compared to normal controls (p=0.0204), with subsequent measurements of elevated CEA levels observed in the LC group when compared to non-smokers and smokers (p=0.023). Conclusion: This study showed that protein can be detected in the exhaled breath condensate of patients, with a significantly elevated amount in the samples from newly diagnosed LC patients. The mechanism for these differences remains to be determined but may be related to inflammatory changes within the airway, such as vascular protein leakage and release of mediators. Future work may aim to identify the upregulated proteins, and focus on proteomics and tissue microarrays to explore candidate proteins.
| Identifer | oai:union.ndltd.org:ADTP/243024 |
| Date | January 2009 |
| Creators | Tran , Vanessa Hoang, Medical Sciences, Faculty of Medicine, UNSW |
| Publisher | Publisher:University of New South Wales. Medical Sciences |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://unsworks.unsw.edu.au/copyright, http://unsworks.unsw.edu.au/copyright |
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