Clinical Use of Measuring Trough Levels and Antibodies against Infliximab in Patients with Pediatric Inflammatory Bowel Disease.
OBJECTIVE
The clinical use of measuring infliximab (IFX) trough levels (TLs) and antibodies against IFX (ATIs) in patients with pediatric inflammatory bowel disease (IBD) remains unclear. We propose measuring these variables to create individual IFX treatment strategies for patients with pediatric IBD.


METHODS
This retrospective study was conducted in pediatric patients with IBD who received IFX from July 2009 to June 2014.


RESULTS
Samples were available from 39 patients with pediatric IBD. A significant difference was observed in IFX TLs in 16 patients who were in clinical remission (group A) after IFX therapy (median, 3.99 μg/ mL; interquartile range [IQR], 0.30 to 21.96) compared to 23 patients who had a poor response to treatment (group B) (median, 0.88 μg/mL; IQR, 0.00 to 6.80, p=0.002). In group B, 21 patients underwent empiric intensification of IFX treatment. After dose intensification, 17 patients had an improved response to treatment. Four patients still had no response to dose intensification. Therefore, these patients were switched to other biologics.


CONCLUSIONS
Patients who had poor responses and subtherapeutic IFX TLs had an improved response to dose intensification. Patients who had ATIs were likely to continue to have no response after dose intensification. Therefore, tailoring individual IFX treatments based on IFX TLs, ATIs, and the clinical response should be considered.
Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
So Yoon
SY
Choi
Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Ben
B
Kang
Department of Pediatrics, Korea University Ansan Hospital, Korea University School of Medicine, Ansan, Korea.
Jee Hyun
JH
Lee
Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Yon Ho
YH
Choe
D000293:Adolescent; D000906:Antibodies / Q000097:blood* / Q000276:immunology; D002648:Child; D003093:Colitis, Ulcerative / Q000188:drug therapy*; D003424:Crohn Disease / Q000188:drug therapy*; D016903:Drug Monitoring; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005765:Gastrointestinal Agents / Q000097:blood / Q000276:immunology / Q000627:therapeutic use*; D006801:Humans; D000069285:Infliximab / Q000097:blood / Q000276:immunology / Q000627:therapeutic use*; D008297:Male; D012074:Remission Induction; D012189:Retrospective Studies; D016896:Treatment Outcome
D000906:Antibodies; D005765:Gastrointestinal Agents; D000069285:Infliximab
Antibodies; Infliximab; Pediatric inflammatory bowel disease; Trough level