Self-Classified Topic Area(s): Breath and VOC Analysis
Volatile Organic Compound (VOC) Profiling in Liver Disease via Selected-Ion Flow-Tube Mass Spectrometry (SIFT-MS)
Michael J Hewitt, Ilaria Belluomo, Piers R Boshier, Mark Thursz, George B Hanna Imperial College London
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Michael Hewitt (Presenter) Imperial College London
Presenter Bio: I am currently working at Imperial College London as a Clinical Research Fellow, undertaking a PhD under the supervision of Professor George Hanna.
I completed my undergraduate training in medicine with an intercalated BSc in gastroenterology and hepatology at Imperial College London in 2012. Since then, I have gone on to complete foundation medical training and core medical training. I hold a gastroenterology training number in North East London and am currently taking time out of my training to undertake research.
I have a keen interest in the liver and my current research is focusing on the potential diagnostic capabilities of volatile organic compounds for liver disease.
Relevant Financial Disclosures
(within past 24 months)
No relevant financial relationship(s) to disclose.
Abstract
INTRODUCTION:
Chronic liver disease and cirrhosis are associated with significant morbidity and mortality and represent a major burden to health services. Multiple underlying aetiologies, unclear diagnostic pathways and late presentation of clinical signs are all challenges to improved detection and management of liver disease. The detection of volatile organic compounds (VOCs) in breath by mass spectrometry has the potential to discriminate between healthy controls and patients with liver disease.
OBJECTIVES:
The primary objective of this study is to measure the VOC profile of patients with liver disease via selected-ion flow-tube mass spectrometry (SIFT-MS).
METHODS:
Patients attending St Mary’s Hospital for hepatology investigations or follow up were invited to participate in this study. Patients having an ultrasound were required to be fasted for a minimum of 4 hours prior to the scan and any patients who had not been fasted had a food diary taken for the preceding 12 hours. Patients were asked to provide six tidal exhalations into the heated inlet of the SIFT-MS instrument (Syft Voice200ultra). This method permits real time quantification of selected VOCs via direct injection. VOCs previously identified as being significantly different in liver disease were selectively analysed. Patients were then divided into four categories on the basis of their pre-existing pathology or radiology results: (i) healthy, (ii) healthy with risk factor for liver disease (e.g. viral hepatitis), (iii) fibrosis and (iv) cirrhosis.
RESULTS:
41 participants were recruited (34 male; median 54.5 years, range 24-81 years): 6 healthy, 15 with risk factor for liver disease, 7 fibrosis patients and 13 cirrhotic patients. There was a significant difference in the levels of nonanone (0.40ppb vs. 0.78ppb) and octanone (1.02ppb vs. 1.78ppb) between healthy controls and cirrhotic patients. Limonene was significantly higher in healthy controls with risk factors compared to cirrhotic patients (4.40ppb vs. 8.80ppb). Propanol was significantly higher in both healthy controls and healthy controls with risk factors compared to cirrhotics (80.55ppb vs. 67.20 ppb vs. 33.38 ppb) . When only including patients that had fasted, the variability was reduced across all cohorts.
CONCLUSION:
This data set raises the possibility that VOC profiles in breath could be used to discriminate between healthy and diseased livers and form the basis of non-invasive screening test. Further work needs to be done to standardise breath testing including consideration of dietary exclusions prior to undertaking breath analysis via mass spectrometry.
= Discovery stage.
= Translation stage.
= Clinically available.
