Serum Zonulin and Claudin-5 but not Interferon-Gamma and Interleukin-17A Levels Increased in Children with Specific Learning Disorder: A Case-Control Study.

Background: Gut-blood and blood-brain barrier permeabilty (gut-brain axis) has been attracting increased attention in the etiology of neurodevelopmental disorders. In this study, we aimed to investigate serum levels of zonulin (a biomarker of intestinal permeability), claudin-5 (a biomarker of blood-brain barrier permeability), and interferon-gamma and interleukin-17A in children with specific learning disorder. Methods: Forty-three children with DSM-5 diagnosis of specific learning disorder and 43 healthy children were included in this study. Serum levels of zonulin, claudin-5, interferon-gamma, and interleukin-17A were measured using commercial enzyme-linked immunosorbent assay kits. Results: Serum zonulin and claudin-5 levels of the study group were significantly higher than the control group according to the multivariate analysis of covariance test while controlling for age, gender, and body mass index. However, serum interferon-gamma and interleukin-17A levels were not significantly different between the two groups. There was no correlation either between zonulin and interferon-gamma and interleukin-17A or claudin-5 and interferon-gamma and interleukin-17A. Conclusion: Gut-blood and blood-brain barrier permeability may be disrupted in subjects with special learning disorder. Further research is needed to determine whether zonulin and claudin-5 may be biomarkers, and some dietary interventions or specific agents such as zonulin or claudin-5 inhibitors could be used in the management of neurodevelopmental disorders including special learning disorder.

Executive Functions and Social Responsiveness in Children and Adolescents With Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder.

Objective: To evaluate the executive functions and social reciprocity of children and adolescents diagnosed with autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) and compared them with healthy controls. Material and Method: Patients aged 6-17 years diagnosed with ASD (n = 33) and ADHD (n = 37) and healthy controls in the same age range (n = 33) were included in the study. Behavioral Rating Inventory of Executive Functions (BRIEF) sub-scales and Social Responsiveness Scale (SRS) were used for evaluating executive function areas and social responsiveness. Results: Our results revealed that children and adolescents with ASD and ADHD were significantly impaired for all BRIEF sub-scales except emotional control and that the significant increase in sub-scale scores expressing deterioration continued after adjustment for SES, verbal IQ scores, and gender. ASD patients received significantly higher SRS scores compared to ADHD and control groups and ADHD patients also had significantly higher values compared to the controls. Conclusion: Further studies with parent-report scales that allow easier and faster evaluation of executive functions and social reciprocity will contribute to better understanding of the personal needs of children with neurodevelopmental disorders and the finding of new treatments.