A67 RAPID REDUCTION IN ANXIETY SCORES IN IBD PATIENTS AFTER INFLIXIMAB INFUSION IS ASSOCIATED WITH CHANGES IN KYNURENINE/TRYPTOPHAN METABOLISM

Abstract

Background: Patients with inflammatory bowel disease (IBD) frequently suffer from psychiatric comorbidities, mainly anxiety and depression. Infliximab, an anti‐TNFα antibody, is commonly used for treatment of colitis. There are anecdotal reports of IBD patients having improvement in mood only hours after infliximab infusion, well before intestinal mucosal healing could occur. Aims: To evaluate the immediate effects of infliximab infusion on intestinal and extra‐intestinal symptoms and immune markers in IBD patients. Methods: IBD patients attending the McMaster University and Charlton infusion clinics were enrolled in the study. Patients were examined at baseline (day 0), 1 day, and 7 days after the infliximab infusion. We assessed anxiety and depression (HAD and STAI‐Y scales), disease specific quality of life (SIDBQ), as well as disease activity scores using the Harvey Bradshaw Index (HBI) or the Mayo Score. Serum C‐reactive protein (CRP), kynurenine, tryptophan, and serotonin levels were measured at each visit. Results: We enrolled 41 IBD patients (Crohn's disease = 35, Ulcerative Colitis = 5, indeterminate colitis = 1; median age 33 yrs, median disease duration 9 yrs). Disease activity decreased at day 1 compared to baseline (p=0.01), but this was not sustained at day 7. Anxiety scores (HADS‐A) decreased significantly at day 1 (p=0.006), and remained lower at day 7 (p=0.009). An improvement in quality of life (SIBDQ) was seen only at day 7 (p=0.017). The decrease in anxiety scores strongly correlated with the improvement in quality of life (SIBDQ r=‐0.81; p<0.001) at day 1 and day 7. The kynurenine/tryptophan ratio decreased significantly at day 1 (p=0.025) and remained lower at day 7 (p=0.047). However, CRP levels did not change during the study period. Conclusions: Infliximab infusion induces rapid changes in anxiety and disease activity. We hypothesise that this effect is central, mediated through changes in kynurenine/tryptophan metabolism, and not through improvement of gut inflammation.