P406 Clinical correlations of infliximab trough levels and antibodies to infliximab in Korean patients with Crohn's disease
Oh E.H.*1, Ko D.-H.2, Seo H.3, Chang K.3, Kim G.-U.3, Song E.M.3, Seo M.3, Lee H.-S.4, Hwang S.W.3,5, Yang D.-H.3, Ye B.D.3,5, Byeon J.-S.3, Myung S.-J.3, Yang S.-K.3,5, Park S.H.3,5
1University of Ulsan College of Medicine, Asan Medical Center, Department of Internal Medicine, Seoul, South Korea 2Hallym University College of Medicine, Dongtan Sacred Heart Hospital, Department of Laboratory Medicine, Hwaseong, South Korea 3University of Ulsan College of Medicine, Asan Medical Center, Department of Gastroenterology, Seoul, South Korea 4University of Ulsan College of Medicine, Asan Medical Center, Health Screening and Promotion Center, Seoul, South Korea 5Asan Medical Center, University of Ulsan College of Medicine, Inflammatory Bowel Disease Center, Seoul, South Korea
The clinical implications of infliximab trough levels (IFX-TLs) and antibodies to infliximab (ATI) levels in routine clinical practice are still being debated. Because limited data are available in Asian patients with inflammatory bowel diseases, we analyzed these variables in patients with Crohn's disease (CD) receiving IFX as maintenance therapy.
IFX-TL and ATI level were measured using prospectively collected samples obtained with informed consent from CD patients being treated at Asan Medical Center, Korea. We analyzed the correlations between IFX-TLs/ATI levels and the clinical activity of CD (quiescent vs active disease) based on the CD activity index (CDAI), C-reactive protein level, and physician's judgment of patients' clinical status at enrollment. The impact of concomitant immunomodulators was also investigated.
This study enrolled 138 patients with CD (84 with quiescent and 54 with active disease). In patients with quiescent and active diseases, the median IFX-TLs were 1.423 μg/mL and 0.163 μg/mL, respectively (p<0.001) and the median ATI levels were 8.064 AU/mL and 11.209 AU/mL, respectively (p<0.001). In the ATI-negative and -positive groups, the median IFX-TLs were 1.415 μg/mL and 0.141 μg/mL, respectively (p<0.001). In patients with and without concomitant immunomodulator use, there were no differences in IFX-TLs (0.632 μg/mL and 1.150 μg/mL, respectively; p=0.274) or ATI levels (8.655 AU/mL and 9.017 AU/mL, respectively; p=0.083).
IFX-TL/ATI levels were well correlated with the clinical activity in Korean CD patients. Our findings support the usefulness of IFX-TLs/ATIs in treating CD patients receiving IFX in clinical practice.