Combination therapy with anti-TNFs and thiopurines does affect drug metabolite levels but it is not associated with body composition in inflammatory bowel disease patients: A cross-sectional study

In this cross-sectional, real-life study we have investigated the potential association between 6-thioguanine nucleotide (6-TGN) and anti-TNF [infliximab (IFX), adalimumab (ADA)], anti-drug antibody levels and body composition parameters. Based on our results thiopurine and anti-TNF combination therapy resulted in decreased antibody formation in IFX-treated patients. AZA-ADA-treated patients showed increased anti-TNF drug concentrations, regardless of antibody formation. Drug metabolites did not correlate with body composition parameters.