Is there a correlation between infliximab trough levels and the development of adverse events in patients with inflammatory bowel disease?

Background/Aims The measurement of infliximab trough levels (IFX-TLs) in patients with inflammatory bowel disease (IBD) is performed to optimize treatment. However, the association between the development of adverse events (AEs) and IFX-TLs has not been sufficiently studied thus far. To investigate the possible association of IFX-TLs with AEs in Greek patients with IBD receiving maintenance treatment with IFX. Methods A retrospective analysis of the registry data of the Gastroenterology Department of the University Hospital of Heraklion, from IBD patients with at least one available IFX-TL measurement during the years 2016 to 2017 was conducted. AEs reported 4 months before and 4 months after the measured IFX-TLs were recorded. The IFX-TLs of patients with or without AEs were compared. Results Of a total of 83 IBD patients (61 Crohn’s disease [73%]; 52 men [63%]; mean age ± standard deviation, 43.3 ± 16.0 years), 147 measurements of IFX-TLs were available (median 4.69 μg/mL [1.32–9.16]), and 99 AEs (67.3%, 14 severe) were registered. The median IFX-TL of patients with AEs was 5.79 μg/mL (1.36–10.25), higher than the median IFX-TL of patients without AEs (3.40 μg/mL [1.30–5.92]), but the difference was not significant (P=0.97). The presence of infections or dermatologic reactions was not correlated with IFX-TLs. There was no difference in the prevalence of the total AEs (66.7% vs. 73.3%, P=0.77) or in the analysis of AEs by group between patients with IFX-TLs ≥ 15 μg/mL and patients with IFX-TLs < 15 μg/mL. Conclusions IFX-TLs are not significantly associated with the development of AEs in IBD patients receiving maintenance treatment with IFX.