Abstract
For severe forms of ulcerative colitis (UC), a chronic inflammatory bowel disease (IBD), biological therapies, including tumor necrosis factor inhibitors (anti-TNF), are often used. However, these drugs have a high variability in treatment response. Multiple factors, such as genetic variants, can affect this variability. The goal of the study was to verify if selected candidate variants could affect response to anti-TNF in UC treatment. This association study included 76 participants suffering from UC and past or current users of anti-TNF. Clinical data for phenotyping was collected through a single visit with the participant and a medical chart review. Blood or saliva samples were collected to extract DNA and to genotype eight selected candidate variants in genes TNF, TNFAIP3, TNFRSF1 A and TNFRSF1B. For anti-TNF users, 30% of individuals were non-responders, 70% suffered from AE and none of the studied variants was associated with the response's phenotype. However, for infliximab users only (n = 44), the TNFRSF1B-rs1061622 variant was associated with nonresponse to infliximab for the first time in a cohort of UC patients (p-value = 0.028). Next steps are to replicate this association in independent cohorts and to perform functional studies to gain more evidence on the variant.