Volatile Organic Compounds for the Assessment of Liver Disease
Volatile Organic Compounds for the Assessment of Liver Disease
This study aims to determine whether a breath test could be used for early detection of
 hepatic fibrosis, cirrhosis or hepatocellular carcinoma.

 Patients who are attending for a planned liver outpatient services or investigations will be
 approached to provide a breath sample.

 Multi platform mass spectrometry analysis will be performed to establish volatile biomarkers
 that can discriminate between fibrosis, cirrhosis and hepatocellular carcinoma.
Volatile organic compound (VOCs) emitted from the human body have been of interest to
 researchers for several decades. In 1971, Pauling et al reported that breath and urine
 contained approximately 250 and 280 VOCs respectively in normal human subjects. VOCs are
 traditionally measured in food industry and counter-terrorism. Routine clinical applications
 include the alcohol breathalyser, 13-C urea breath test for H. pylori, nitric oxide in
 asthma, and hydrogen/methane test for bacteria overgrowth.

 Preliminary work has suggested that there is alteration in the VOC profile of patients with
 liver disease. It is suggested that as fibrosis increases, liver function is impaired,
 resulting in increased levels of certain compounds. These compounds are then present at
 higher levels within the blood stream and when they reach the lungs, they are exhaled. There
 has also been work demonstrating a change in the profile of VOCs within cancers,
 demonstrating specific "breath signatures" in patients with oesophageal cancer. At Imperial
 College London, Marker et al have developed a breath test as screening test for oesophageal
 cancer with comparable sensitivity and specificity to other screening methods (e.g. faecal
 occult blood testing). The investigators would aim to achieve similar with hepatobiliary
 disease via a prospective cross-sectional study aimed at determining the diagnostic accuracy
 of exhaled breath volatile organic compounds (VOC) for the detection of liver disease.

 Patients will be recruited from outpatient clinics and hospital wards based across Imperial
 College Healthcare Trust. They may also be recruited from the radiology department when
 attending for liver biopsies or hepatocellular carcinoma surveillance ultrasound scans. When
 attending for their appointment, a member of the research team will discuss the research
 project with the patient, explain that is requires the patient to provide a breath +/- urine
 sample. Patients will be provided with a patient information leaflet. If the patient is to
 agree to this, they will be asked to sign a written consent form. If a recent PHES test has
 not been performed, one will be conducted otherwise no additional investigations, invasive or
 otherwise will be required of the patients.

 For patients under regular follow up within the trust, they may be asked to consent to
 further breath samples being taken at future appointments to facilitate longitudinal follow
 up. Patients will be entitled to withdraw at any point.

 Patients attending for endoscopy, fibroscan or liver biopsy will have been nil by mouth for
 4-6 hours prior to the procedure as per local guidelines. For those attending outpatient
 appointments, if identified prior to their appointment by their clinical team, the
 investigators will aim to contact the patients and request that they fast. Should they not be
 fasted, they may be asked to perform basic oral hygiene techniques (e.g. rinsing mouth with
 water), prior to the breath sample being taken. A food diary of the preceding 24 hours will
 be taken as part of the pre-sampling questionnaire.

 As part of the consent process, patients will also be asked permission to access their
 hospital records for the purpose of the research study only, including their blood tests,
 radiology and pathology results. All data will be anonymised and all hospital records shall
 be handled with strict confidentiality in accordance with the Data Protection Act 1998 and
 the General Data Protection Regulation (GDPR).

 Patients will be asked to give a number of exhalations into a breath sampling device until a
 defined volume of breath has been sampled. This may be done via one of several techniques.
 The investigators preferred option is that they breathe into a custom designed nalophan bag
 which is attached to thermal desorption tubes and a breath sampling device. Alternatively,
 patient may be asked to perform normal tidal breathing whilst wearing a face mask, which
 takes around 2 minutes on average. Patients located at St Mary's Hospital may also be asked
 to breathe directly into a mass spectrometer machine (SYFT Voice200Ultra). This mass
 spectrometer instrument is a self-contained mobile device which can be moved between clinical
 areas within St Mary's Hospital. Sampling by this method will involve a single deep nasal
 inhalation followed by complete exhalation via their mouth into a plastic cylinder connected
 to a tube leading to the mass spectrometer itself. This is repeated three times within a 60
 second window. The investigators expect the breath sampling process to take no longer than
 5-10 minutes in total. Patients will be requested to pass urine into a standardised 60ml
 urine specimen vial, which will be immediately sealed. 20ml of urine will be aliquoted into a
 standard 60ml specimen vial.

 The VOCs from the breath will be trapped onto adsorbent tubes inserted into the breath taking
 device. After sampling the adsorbent tube is removed from the device, capped and transported
 back to the laboratory at St Mary's Hospital London for analysis. Samples will be transported
 by courier or by a member of the research team. The sample(s) shall undergo analysis via mass
 spectrometry instruments, at St Mary's Hospital London.

 Breath VOCs sampled on adsorbent tubes will be analysed within 48 hours of collection. The
 sample constituents are destroyed within the mass spectrometer for detection meaning that no
 clinical material will remain after analysis by the mass spectrometry instruments. Urine
 samples will be stored within a registered tissue bank in accordance with the Human Tissue
 Act and disposed of following analysis.

 As part of the study, the investigators will aim to follow patients up longitudinally to
 ascertain if a participant's VOC profile changes with progression or regression of liver
 disease. At each appointment, before sample is taken, the participant's consent will be
 reviewed and if the participant is still willing to continue in the study, further breath and
 urine samples will then be collected. This would be for a maximum of 24 months.
Inclusion Criteria:

 -  Patients seen in secondary care with suspected or confirmed liver / pancreatic disease
 or hepatocellular carcinoma / pancreatic cancer

 -  Patients able to understand and retain the information provided, thereby being able to
 give informed consent for inclusion in this study

 Exclusion Criteria:

 -  Patients who lack capacity or unable to provide informed consent.

 -  Any patient outside the established age range (18-90years).

 -  Patients unable to fast.