Inclusion Criteria:  2-18 years old diagnosis of Crohn's Disease receiving exclusive enteral nutrition or corticosteroids as first-line treatment, Pediatric Crohn's disease Activity Index (PCDAI)>10 or The Simple Endoscopic Score for Crohn Disease (SES-CD)<3 after exclusive enteral nutrition or corticosteroids  Exclusion Criteria:  history of biological agents targeting at tumor necrosis factor (TNF) Crohn's Disease-related surgery infections tumors