P408 Long-term impact of the decrease of infliximab trough levels on the disease course in Inflammatory Bowel Disease patients under maintenance treatment with infliximab
E. Orfanoudaki1, M. Gazouli2, K. Foteinogiannopoulou1, E. Theodoraki1, E. Legaki2, I. Koutroubakis1
1Gastroenterology, University Hospital of Heraklion, Heraklion Crete, Greece, 2Laboratory of Biology- Department of Basic Medical Science, National and Kapodistrian University of Athens, Athens, Greece
Background
The measurement of infliximab trough levels (IFX-TLs) has been suggested as an important biomarker for the optimisation of treatment in patients with inflammatory bowel disease (IBD). We have previously reported that IFX-TLs of patients under maintenance treatment with IFX show decreasing patterns associated with an increasing pattern of CRP levels1. We aimed to study the clinical impact of this observation by recording the treatment changes that became necessary during a three year follow-up.
Methods
Consecutive asymptomatic patients on maintenance treatment with IFX were included. Two different measurements of IFX-TLs were made (ELISA, Eagle BioSciences) with a ten-month interval using serum samples drained before IFX infusion. After the second measurement patients were followed up for three years and all treatment modifications including IFX intensification, change of biologic agent or IBD-related surgical intervention were assessed.
Results
Among a total of 86 IBD patients under maintenance treatment with IFX, 64 [49 CD, 15 UC, 42 men, mean age 44.2 ± 15.2 years, 41 in combination therapy with immunomodulator, 6 in intensified dose], with 2 available measurements of IFX-TLs (A and B) were included in the study. Median levels of IF-TLs were 5.07 (IQR 1.60–12.73) μg/ml in measurement A and 4.68 (1.19–7.83) μg/ml in measurement B (
Conclusion
IBD patients who are on maintenance treatment with infliximab showing decreasing patterns of IFX-TLs often need treatment optimisation during the follow-up due to clinical or endoscopic activity. These results probably suggest the importance of the proactive therapeutic drug monitoring and early treatment optimisation in these patients
Orfanoudaki E, Gazouli M, Foteinogiannopoulou K et al. Infliximab trough levels are decreasing over time in patients with inflammatory bowel disease on maintenance treatment with infliximab. Eur J Gastroenterol Hepatol 31:187–191