In: Biomarkers in Inflammatory Bowel Diseases

Adverse drug reactions (ADRs) result in morbidity and mortality as well as placing a significant financial burden on health-care resources. In Europe and North America, they are responsible for approximately 6% of all hospital admissions. Patients with inflammatory bowel disease (IBD) commonly experience adverse drug reactions. Whilst the explosion of new IBD therapies has improved patient outcomes, ADRs remain a significant challenge and for many drugs the major cause of discontinuation. Most ADRs cannot currently be reliably predicted prior to starting treatment, and therefore clinical and laboratory monitoring, which is expensive and inconvenient for patients, is recommended for the duration of treatment. An ability to accurately predict an individual’s risk of developing an ADR prior to treatment may allow the dose to be altered or the drug avoided in at-risk individuals. Pharmacogenetic biomarkers are particularly attractive for the purpose of predicting ADRs as they are present at diagnosis and unaffected by disease phenotype, disease activity or other treatments. Discovery of these biomarkers has been made possible by the increasing availability of reliable, robust and cheap high throughput genotyping and sequencing platforms. In this chapter, we describe several inflammatory bowel disease ADR pharmacogenetic biomarkers, as well as the process of biomarker discovery and the barriers which hinder the successful ‘bench to the bedside’ translation of these tests into routine clinical care