Volatiles in Exhaled Breath and Blood in Crohn's Disease: Validation Cohort

In the recent study(doi: 10.1097/Mib.0000000000000436) it was shown the potential of analysis
of exhaled air to differentiate active and inactive state of Crohn's Disease (CD). Although,
the molecules found in this cohort have shown potential to differentiate between CD patients
in remission or with active disease, the validation of the outcomes has to be performed in
new population. One crucial pathophysiologic factor in CD is excessive lipid peroxidation
during oxidative stress, i.e. during overproduction of oxidants compared to the protective
antioxidants. Oxidative stress is a potential aetiological factor and/or a triggering factor
in CD. Many volatile compounds including hydrocarbons and aldehydes are produced during
oxidative stress and they can be non-invasively measured in exhaled air 5, 6. However,
exhaled breath contains volatile metabolites originating from previous or current uptake of
environmental contaminants, and more interestingly from metabolism of foreign organisms
(bacteria, viruses, fungi or yeasts). Therefore, it is important to study not only exhaled
air but also blood in which blood borne volatile molecules can be measured. Since the current
study also aims for validating the use of volatile molecules in exhaled air as non-invasive
markers for disease activity in CD patients, the investigators will compare the outcome of
exhaled air analysis with currently established non-invasive measure of disease activity,
i.e. fecal calprotectin.

Inclusion Criteria:

- Age: 18-65

- BMI: 19-30

- scheduled colonoscopy

Exclusion Criteria:

- disease compromising immune system (such as HIV positive status or patients after
organ transplantation

- liver disease

- active and untreated tuberculosis

- chemotherapy agents