Anti-TNF Non-Response in Ulcerative Colitis: Correcting for Mucosal Drug Exposure Reveals Distinct Cytokine Profiles

It remains unclear why up to 30% of ulcerative colitis patients (UC) do not respond to tumor necrosis factor inhibitors (TNFi). Validated biomarkers for (non-)response ((N)R) are lacking. Most studies investigating underlying mechanisms do not differentiate between pharmacokinetic and inflammatory mechanisms. We therefore aimed to develop a framework to correct for mucosal drug exposure (MDE) and applied this on mucosal cytokine profiles previously linked to (N)R.