INTESTINAL FATTY ACID-BINDING PROTEIN AS A MARKER FOR THE SMALL INTESTINE CONDITION IN CHILDREN WITH AUTISM

The diagnostic value of intestinal fatty acid-binding protein (I-FABP) as a potential marker for small intestinal mucosal integrity has been studied in recent years. This cytoplasmic protein in enterocytes transports fatty acids to the site of lipid synthesis in the endoplasmic reticulum from the apical membrane of the enterocyte. The purpose of the research was to evaluate the level of I-FABP in children with autism spectrum disorders (ASD) depending on the adherence to a gluten-free diet (GFD) and comped to the healthy peers. Research materials and methods: a single-center, prospective, observational, continuous, controlled study of 230 children aged 3 to 15 y/o was conducted in 2019 - 2020. Group 1 included 36 children with ASD who had been on fasting for more than 6 months: 23 (64%) boys/13 (36%) girls. 49 patients with ASD without dietary restrictions made up the Group 2: 35 (71%) boys/14 (29%) girls. The [control] Group 3 included 145 apparently healthy children: 83 (57.3%) boys/62 (42.7%) girls. The patients’ median age in Group 1 was 6.5 [4.0; 8.0] y/o, 6.0 [4.0; 7.0] y/o in G2, and 8.0 [6.0; 11.0] y/o in G3, with the differences being statistically significant (p=0.0001). I-FABP was determined in blood serum by enzyme-linked immunosorbent assay using “Human Casomorphin” and “Human I-FABP” reagent kits (ELISA Kit by “Hycult Biotech, Inc.” Netherlands, with the determination error = 3.2%, 100% method sensitivity, 85% specificity). Results: the median level of I-FABP in blood serum in children with ASD on GFD was statistically significantly (5.6 times) lower compared to children who did not comply with GFD (107.4 [92.70; 197.20] pg/ml and 601 [295.7; 715.3] pg/ml) and 5.1 times lower than the level in the control group (107.4 [92.70; 197.20] pg/ml and 543.80 [388.0; 750.0] pg/ml) (p<0.001). There were no statistically significant differences in I-FABP levels between children in the control group and patients with ASD who did not use diet therapy (p=0.369). There was no statistically significant correlation found - in all groups - between the level of I-FABP and the patients’ age. Conclusion: the obtained results confirm the hypothesis of increased intestinal permeability in children with autism, which may be pathogenetically significant for some patients with ASD, and this must be taken into account in a personalized approach to prescribing the diet therapy. The GFD for children with ASD helps reducing the damage to the small intestine if are having gluten sensitivity.