A101 NO ASSOCIATION WITH RISK OF INFECTION IN IBD WITH HIGH SERUM INFLIXIMAB LEVELS

Improved rates of clinical outcome in IBD are associated with higher IFX levels and some patients are treated with higher than standard dosing due to suboptimal response. Data evaluating the correlation between IFX levels and toxicity is limited. To evaluate the safety of IFX in IBD patients and compare the frequency of adverse events (AE’s) in relation to their levels We performed a retrospective analysis of 180 patients with at least one measurement of serum IFX from 2012 through 2016. The cohort was divided separately according to an IFX level cut-off of 15 ug/ml and into 3 groups based on IFX concentrations (<8; 8–20; >20). Frequencies of AE’s were compared using logistic regression. The frequency of total AE’s was significantly higher in patients with IFX levels less than 15 ug/ml (64% vs 34%; p=0.02). Infusion reactions were also more frequent in the NR group (10% vs 0% p=0.015). However, there were no significant associations between the rate of infections, skin manifestations or serious AE and IFX levels. No significant differences in rates of infections were demonstrated among the 3 groups of IFX levels. Higher IFX levels were not associated with higher rates of infections. Clinicians and patients should be aware of the risks of AE with IFX therapy but higher dosing should not be avoided if clinically indicated. None