Whole transcription profile of responders to anti-TNF drugs in pediatric inflammatory bowel disease

Background: In pediatric inflammatory bowel disease (IBD) up to 30% of patients do not respond to anti-TNF therapy. The aim was to identify pharmacogenomic markers that predict early response to anti-TNF drugs in pediatric patients with IBD. Methods: The study population included 29 responders and 9 non-responders to anti-TNF therapy patients aged <18 years with IBD who started treatment with infliximab or adalimumab. Whole gene expression profiles from total RNA isolated from whole-blood samples of 6 responders and 6 non-responders taken before biologic administration and after 2 weeks were analyzed by RNA next-generation sequencing. The expression of 6 selected genes was measured for validation in all of 38 patients recruited using qPCR; Results: Differentially expressed genes in non-responders versus responders to anti-TNF treatment were identified, 32 prior treatment initiation and 44 after 2 weeks (Log2FC (Fold change)>0.6 o <-0.6 and p value < 0.05). After validation, FCGR1A, FCGR1B and GBP1 were overexpressed in non-responders after 2 weeks of anti-TNF treatment (Log2FC 1.05, 1.21 and 1.08, respectively, p value <0.05,); Conclusion: Expression of the FCGR1A, FCGR1B, and GBP1 genes is a pharmacogenomic biomarker of early response to anti-TNF agents in pediatric IBD. Overall design: Whole gene expression profiles from total RNA isolated from whole-blood samples of 6 responders and 6 non-responders taken before biologic administration and after 2 weeks were analyzed by RNA next-generation sequencing.