Background: Adequate infliximab (IFX) trough levels (TL) are associated with clinical remission (CR) and mucosal healing (MH). We aimed to investigate the association between ITX TL and quality of life (QoL) in inflammatory bowel disease (IBD) patients.
Methods: We carried out a prospective cohort study in IBD patients in IFX maintenance therapy. IFX levels were determined using a quantitative rapid test immediately before drug infusion. Disease activity indices (MAYO/HBI), endoscopic scores (MAYO/SES-CD) were obtained. QoL was assessed using the Inflammatory Bowel Disease Questionnaire (IBDq). The study was approved by the Institutional Review Board and informed consent was obtained from all patients.
Results: Seventy-one consecutive subjects were included in the study (59 with Crohn's disease and 17 with ulcerative colitis). Drug levels were considered satisfactory (TL≥3μg/mL) in 29 patients (39.4%) and unsatisfactory (TL<3μg/mL) in 43 (60.6%). Satisfactory TL were associated with higher rates of clinical remission (85.7% x 27.9%, p<0.001) and mucosal healing (85.7% x 18.6%, p<0.001). Higher TL were also associated with improved IBDQ scores (183±32 x 161±28, p=0.006), particularly regarding bowel symptoms (59.6±9.3 x 52.3±8.5, p=0.001), systemic function (27.3±5.6 x 22.7±5.2, p=0.001) and social function (30.8±5.7 x 26.7±7.4, p=0.015).
Conclusions: Satisfactory IFX levels were associated with higher rates of CR, MH and improved QoL in IBD patients on maintenance therapy.