New non-invasive biomarkers of intestinal inflammation and increased intestinal permeability in pediatric inflammatory bowel diseases and their correlation with fecal calprotectin: a pilot study.

ABSTRACT

BACKGROUND: Increased intestinal permeability is considered to play a crucial role in the pathogenesis of inflammatory bowel diseases (IBD). Therefore, recently, the use of non-invasive biomarkers in both diagnosis and monitoring IBD is emphasized. The aim of this study was to investigate fecal and serum zonulin and serum I-FABP in pediatric IBD patients and their correlation with fecal calprotectin (FCP). METHODS: Seventy-one individuals 32 Crohn's disease (CD) patients, 33 ulcerative colitis (UC) patients and 6 controls were examined for fecal and serum zonulin and plasma I-FABP. Values were correlated to FCP and to each other for all children included in the study. A stool specimen and blood samples were collected during check-up visits at hospital. Then fecal and serum zonulin, I-FABP and FCP were tested by ELISA test. Non-parametric statistical tests were used for data analysis. RESULTS: The level of fecal zonulin and FCP were higher in IBD patients compared to control group (CG) median for CD - 46.0 (7.0-3854) ng/mL, 252.0 (77.0 -1054.2) ug/g; UC - 115.3 (50.7-418.3) ng/mL, 40 (16.0-1883.0) ug/g; CG - 60.8 (31.8-123.0) ng/mL, 41.5 (31.0-323.0) ug/g, respectively, (P<0.05). No statistically significant difference in concentrations of serum zonulin and I-FABP was reported between patients and CG (P=0.55). The only correlation that has been reported was between fecal zonulin and FCP and the strongest one was in CD CD - R = 0.73, UC - R = 0.67, All - R=0.67, CG - R=0.65. CONCLUSIONS: According to our results it seems that only fecal zonulin may serve as another, next to FCP, biomarker of intestinal damage in IBD. However, both fecal and serum zonulin as well as IFABP need further studies to assess their usefulness in diagnostics and monitoring in IBD.