Clinical Significance of Serum Elafin in Children with Inflammatory Bowel Disease

Background: The role of elafin in the pathophysiology of inflammatory bowel disease (IBD) has not been not elucidated. We aimed to evaluate serum elafin in children with IBD and assess its relationship with disease activity. Methods: We enrolled children with IBD in the study group and children with functional abdominal pain in the control group. We evaluated serum elafin using enzyme-linked immunosorbent assay kits. Results: In children with IBD, serum elafin (mean ± SD: 4.192 ± 1.424 ng/mL) was significantly elevated compared with controls (mean ± SD: 3.029 ± 1.366 ng/mL) (p = 0.0005). Elafin was significantly increased in children in the active phase of IBD (mean ± SD: 4.424 ± 1.449 ng/mL) compared with the control group (p = 0.0003). In IBD remission, only children with ulcerative colitis (mean ± SD: 4.054 ± 1.536 ng/mL) had elevated elafin compared with controls (p = 0.004). ROC analysis revealed that the area under the curve (AUC) of serum elafin was 0.809 while discriminating patients with ulcerative colitis from the control group, and the AUC was 0.664 while differentiating patients with Crohn’s disease from the control group. Conclusions: Serum elafin was found to be elevated in our cohort of children with IBD, depending on disease activity. Serum elafin was increased in the active phases of both ulcerative colitis and Crohn’s disease, but only in the remission of ulcerative colitis. Elafin appears to be a potential candidate for a biomarker of ulcerative colitis.