Alternatives in the management of inflammatory bowel disease

This thesis consists of clinical research on optimization of the management of inflammatory bowel diseases (IBD) by exploring alternatives for monitoring and treatment of IBD. Furthermore, research was conducted on the implications of SARS-CoV-2 for patients with various immune-mediated inflammatory diseases (IMID), including IBD.
One aspect of the investigation involved assessing therapy response in Crohn's disease (CD) through pan-enteric capsule endoscopy (Pan-CE), enabling observation of the entire small intestine and colon. Pan-CE demonstrated its efficacy in measuring changes in endoscopic disease activity among CD patients. Additionally, four faecal biomarkers of intestinal inflammation were compared in paediatric Crohn's disease cases: faecal calprotectin (FCP), chitinase 3-like-1 protein (CHI3L1), S100A12, and osteoprotegerin (OPG). Among these biomarkers, FCP proved to be the most suitable indicator of clinical and endoscopic disease activity in children with CD. In another study, a novel POCT (point-of-care testing) device was validated for measuring concentrations of infliximab, adalimumab, and CRP in capillary blood obtained through finger-prick, as well as FCP levels in stool samples.
A randomized controlled trial (RCT) compared placebo to mercaptopurine, with mercaptopurine dosing guided by therapeutic drug monitoring. Mercaptopurine was more effective, as after one year of treatment, a significantly higher number of patients on mercaptopurine achieved clinical, endoscopic, and histological remission. Subsequently, a switch from intravenous vedolizumab maintenance treatment to subcutaneous vedolizumab injections was investigated. Vedolizumab concentration in the blood increased after the transition from infusions to vedolizumab injections, with a correlation between lower disease activity and higher serum drug levels.
Utilizing data from a comprehensive observational study on SARS-CoV-2 in immune-mediated inflammatory diseases, the long-term humoral immune response was explored in patients with confirmed previous SARS-CoV-2 infection. Patients treated with anti-TNF agents (including infliximab or adalimumab) had a lower seropositivity rate following a prior infection. Approximately one-quarter of patients reported increased IMID activity, resulting in treatment intensification in only two percent of these cases.