DETERMINATION OF INFLAMMATORY BOWEL-DISEASE ACTIVITY BY BREATH PENTANE ANALYSIS

PURPOSE: Quantitative determination of breath pentane, an alkane generated by peroxidation of cellular fatty acids, has been used as a noninvasive determinant of inflammation. Herein we report the first examination of the relationship between breath pentane and intestinal inflammation in humans. METHODS: Patients (N = 33), either with a known history of inflammatory bowel disease (IBD) with symptoms of relapse or with no known history of but having symptoms consistent with IBD, were evaluated with indium- 111 -labeled leukocyte imaging to assess the presence of active inflammation. At the time of the indium scan, the exhaled breath of the patients was obtained via a collecting tube. Gas chromatography was used to quantify the pentane content. and these values were compared with graded indium scans. RESULTS: The range of breath pentane found in our population (36 determinations in 33 patients) was from 0 to 38.4 nmol/l of exhaled air. For patients with negative scans, the mean pentane was 2.1 nmol/l, for intermediate scans 3.1, for positive scans 4.3, and for nonintestinal nuclide imaging 5.5 [P = 0.005 by analysis of variance (ANOVA)]. CONCLUSIONS: We have previously demonstrated the correlation of breath pentane with gross and histologic evidence of intestinal inflammation in a rodent colitis model. This current study also demonstrates that pentane analysis can be correlated with inflammatory bowel disease activity in humans.