A Prospective Evaluation of Adalimumab Drug Levels and Anti-Drug Antibodies Using Two Commercial ELISA and the Influence of 6-Thioguanine Nucleotides Amongst Patients With Crohn's Disease
Background: Some, but not all, studies have demonstrated a relationship between therapeutic drug monitoring (TDM) of adalimumab (ADA) and outcomes in Crohn's disease (CD). We evaluated the utility of TDM of ADA in patients with CD using two commercially-available ELISA.
Methods: ADA drug levels (DL) and anti-drug antibodies (ADAb) were measured in CD patients (n=80) from 2 tertiary referral centres, between November 13 and February 14 using the Lisa-Tracker Duo ((LT) Theradiag, France) and Immundiagnostik ELISA ((IM) Germany). Faecal calprotectin (FC), C-reactive protein(CRP;<5ng/mL remission) and clinical activity (Harvey Bradshaw Index,(HBI)<5 remission)were also recorded. LT kits were provided by Theradiag at no cost.
Results: Neither assay showed a significant difference in ADA DL between remission and active disease (Table 1).