Sa1240 LéMann Index Assessment Overtime in Crohn's Disease Patients Treated With Anti TNFs: A Pilot Observational Cohort Study

Abstract

completing the follow-up period of 8 weeks without any thiopurine dose adjustments. Results: Thirty-two patients with leukopenia and 162 patients without leukopenia were included. Patients with leukopenia were more frequently treated with 6MP than AZA: Odds Ratio (OR) = 7.3 (95%CI 3.1 17.0; p < 0.00001). Additionally, these patients were more often co-treated with anti-TNF agents: OR 5.1 (95%CI 1.6 16.4; p = 0.009). At T1 threshold values of ~213 pmol/8×108 red blood cells (RBC) for 6TGN and ~3525 pmol/8×108 RBC for 6MMPR, patients with elevated T1 6TGN or T1 6MMPR levels were at increased risk of leukopenia between week 1 8: Odds ratios were 6.2 (95%CI: 2.8 13.8; p < 0.001) and 5.9 (95%CI: 2.7 13.3; p < 0.001), respectively. Finally, a logistic regression model was designed including the T1 6TGN and 6MMPR threshold parameters, thiopurine type and concurrent anti-TNF therapy at baseline. The predictive performance measured by Receiver Operating Characteristic (ROC) analysis revealed an area under the curve (AUC) of 0.70 (95%CI: 0.59 0.81; p < 0.001), when either T1 6TGN or 6MMPR threshold values were evaluated. Including all parameters, the AUC was 0.84 (95%CI: 0.76 0.92; p < 0.000001). Conclusions: Both 6TGN and 6MMPR metabolites were independently associated with the occurrence of leukopenia during the first 8 weeks of thiopurine therapy. Assessment of 6TGN and 6MMPR metabolite concentrations one week after thiopurine initiation helps to identify patients at risk of developing leukopenia.