P319 Trough levels of adalimumab better correlate with combined mucosal and transmural healing than clinical remission in Korean patients with Crohn’s disease on adalimumab maintenance therapy
E. H. Oh*1, A-R. Yoon2, S. H. Park3, J. Kim1, N. Ham1, E. M. Song1, S. W. Hwang1,2, S. H. Park1,2, D-H. Yang1, J-S. Byeon1, S-J. Myung1, S-K. Yang1,2, B. D. Ye1,2
1Asan Medical Center, Gastroenterology, Seoul, South Korea, 2Asan Medical Center, Inflammatory Bowel Disease Center, Seoul, South Korea, 3Asan Medical Center, Radiology, Seoul, South Korea
Studies on correlations between trough levels of adalimumab (TLAs) and levels of antibody to adalimumab (ATA levels) with combined mucosal and transmural healing as well as clinical remission in Crohn’s disease (CD) in non-Caucasians are still lacking.
TLAs and ATA levels were measured using prospectively collected serum samples drawn from CD patients on adalimumab (ADL) maintenance therapy for more than 1 year at Asan Medical Center, South Korea, from August 2017 to July 2018. We analysed correlations between TLA/ATA levels and combined mucosal and transmural healing as well as clinical remission. TLAs/ATA levels according to concomitant immunomodulator use were also evaluated.
This study included 189 serum samples drawn from 149 patients. Ninety-eight patients were males (65.8%). The median age at diagnosis of CD and at starting ADL was 21.0 years (interquartile range [IQR], 18.0–28.0) and 31.0 years (IQR, 23.0–37.5), respectively. Fifty patients (33.6%) have been previously exposed to infliximab. Clinical remission (Crohn’s disease activity index [CDAI] < 150) was observed in 77.8% (147/189 samples) and combined mucosal and transmural healing was observed in 16.2% (18/111 samples). TLAs differed significantly between two groups divided by a cut-off value of ATA as 4 µg/ml-eq (7.051 µg/ml [IQR 5.185–10.191] in ATI-negative samples [
Abstract P320 – P320
|TLAs (µg/ml)||ATA levels (µg/ml-eq)|
|At the time of measuring TLAs/ATA levels||8.176 (6.009–10.845)||7.291 (5.219–10.926)||0.001 (0.001–0.001)||0.001 (0.001–0.001)|
|During induction period||7.891 (5.337–10.947)||7.626 (5.347–10.861)||0.001 (0.001–0.001)||0.001 (0.001–0.001)|
|Continuously from induction period to the time of measuring TLAs/ATA levels||8.007 (5.526–10.945)||7.291 (5.266–10.668)||0.001 (0.001–0.001)||0.001 (0.001–0.001)|
|*Median (interquartile range)|
TLAs/ATA levels according to concomitant immunomodulator use.
TLAs above 11.79, 12.00 and 14.76 µg/ml (area under the receiver-operating characteristic curve = 0.695) identified patients on deep healing with specificities of 85%, 90% and 95%, respectively.
TLAs better correlated with combined mucosal and transmural healing than clinical remission in Korean CD patients on ADL maintenance therapy. There was no difference in TLAs/ATA levels according to concomitant immunomodulator use.