OC 011 Exhaled volatile organic compound breath analysis in inflammatory bowel disease
Introduction Distinguishing between Crohn's disease (CD) and ulcerative colitis (UC) is important for determining management and prognosis. Selected ion flow tube mass spectrometry (SIFT MS) may be used to analyse volatile organic compounds (VOCs) in exhaled breath: these may be altered in disease states, and distinguishing breath VOC profiles can be identified.1A recent paediatric study used SIFT MS to distinguish IBD patients from healthy controls (HC).2The aim of this pilot study was to identify, quantify and analyse VOCs present in the breath of adult IBD patients and controls, potentially providing insights into disease pathogenesis and complementing current diagnostic algorithms.Abstract OC 011 Table 1 Sensitivity Specificity Q2value CD vs HC 94.4 94.4 0.78 UC vs HC 90.5 94.4 0.66 CD vs UC 88.9 90.0 0.69 Method SIFT MS breath profiling of 56 individuals (20 UC, 18 CD and 18 healthy controls) was undertaken. Multivariate analysis included principal components analysis (PCA) and partial least squares discriminant analysis with orthogonal signal correction (OSC PLS DA) Receiver Operator Characteristic (ROC) analysis was performed for each comparative analysis using statistically significant VOCs. Results OSC PLS DA modelling was able to distinguish both CD and UC from healthy controls and from one other with good sensitivity and specificity. ROC analysis using combinations of statistically significant VOCs (dimethyl sulphide, hydrogen sulphide, hydrogen cyanide, ammonia, butanal and nonanal) gave integrated areas under the curve (AUC) of 0.86 (CD vs HC) 0.74 (UC vs HC) and 0.83 (CD vs UC) Conclusion SIFT MS breath profiling was able to distinguish IBD patients from controls, as well as separate UC from CD, using both multivariate and univariate statistical techniques. The specific VOCs characterising the breath in IBD relate to bacterial dysbiosis (sulphur compounds and ammonia) and oxidative stress (aldehydes)3 both mechanisms implicated in disease pathogenesis. Disclosure of interest None Declared.Abstract OC 011 Figure 1 References Popov TA. Human exhaled breath analysis. Ann Allergy Asthma Immunol. 2011;106(6):451 6 Patel N, Alkhouri N, Eng K, et al. Metabolomic analysis of breath volatile organic compounds reveals unique breathprints in children with inflammatory bowel disease: a pilot study. Aliment Pharmacol Ther. 2014;40(5):498 507 Bos LD, Sterk PJ, Schultz MJ. Volatile metabolites of pathogens: a systematic review. PLoS Pathog. 2013;9(5):e1003311