Too slow recruitment and no staff availability

This study evaluates the use of exhaled air analysis as tool to monitor the disease activity in Crohn's Disease (CD). This study is a validation of the previous findings. In this study the participant will be asked to donate exhaled air, blood samples and fecal samples. The breath samples will be used to measure various volatile metabolites in breath. The breath air will be next used to validate the previous findings. The blood samples will be used to define the origin of volatile metabolites in breath. Finally, the potential of exhaled breath analysis as non-invasive marker of diseases activity will be compared to established fecal calprotectin.

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

Our target population will consist of individuals with established diagnosis of Crohn's Disease (CD). The target population will include male and female between the ages of 18 and 65 years and standard BMI (between 19 and 30). Potential study participants will be excluded if having any disease compromising immune system (such as HIV positive status or patients after organ transplantations), diagnosis of any liver disease, active and untreated tuberculosis and chemotherapy agents. All potential participants must have scheduled appointment for colonoscopy.