Limonene in exhaled breath is elevated in hepatic encephalopathy

M. E. O'Hara*, R. Fernández Del Río, A. Holt, P. Pemberton, Tahir Shah, T. Whitehouse, C. A. Mayhew

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)
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Breath samples were taken from 31 patients with liver disease and 30 controls in a clinical setting and proton transfer reaction quadrupole mass spectrometry (PTR-Quad-MS) used to measure the concentration of volatile organic compounds (VOCs). All patients had cirrhosis of various etiologies, with some also suffering from hepatocellular cancer (HCC) and/or hepatic encephalopathy (HE). Breath limonene was higher in patients with No-HCC than with HCC, median (lower/upper quartile) 14.2 (7.2/60.1) versus 3.6 (2.0/13.7) and 1.5 (1.1/2.3) nmol mol-1 in controls. This may reflect disease severity, as those with No-HCC had significantly higher UKELD (United Kingdom model for End stage Liver Disease) scores. Patients with HE were categorized as having HE symptoms presently, having a history but no current symptoms and having neither history nor current symptoms. Breath limonene in these groups was median (lower/upper quartile) 46.0 (14.0/103), 4.2 (2.6/6.4) and 7.2 (2.0/19.1) nmol mol-1, respectively. The higher concentration of limonene in those with current symptoms of HE than with a history but no current symptoms cannot be explained by disease severity as their UKELD scores were not significantly different. Longitudinal data from two patients admitted to hospital with HE show a large intra-subject variation in breath limonene, median (range) 18 (10-44) and 42 (32-58) nmol mol-1.

Original languageEnglish
Article number046010
JournalJournal of Breath Research
Issue number4
Publication statusPublished - 21 Nov 2016


  • breath analysis
  • cirrhosis
  • hepatic encephalopathy
  • limonene
  • PTR-MS
  • volatile organic compound

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine


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