Assessment of the natural killer cell, IFN- and IL-10 blood levels in children with attention-deficit/hyperactivity disorder.

Abstract

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder, affects millions of youngsters and typically persists into adulthood. The pathophysiology of ADHD may be due to an impaired immune response, common genetics, and environmental linkages, as all have been suggested as potential underlying mechanisms for ADHD. During systemic inflammation, natural killer (NK) cells can produce pro-inflammatory cytokines like interferon (IFN- ) and anti-inflammatory cytokines like interleukin (IL-10); this demonstrates the importance of both of their roles as regulators to counteract inflammation and prevent immune-mediated host damage. In this work we aimed to determine the role of inflammation in children with ADHD by measuring the level of NK cells in peripheral blood compared to typically developing children besides estimating the inflammatory cytokines INF- and IL -10 in both groups. This study included 50 children diagnosed with ADHD based on the Diagnostic and Statistical Manual of Mental Disorders-5th edition and 50 age and sex- matched normally developed children, as controls. The estimation of NK was done using flow cytometry, while the studied cytokines were measured using the ELISA technique. We found that children with ADHD had a significantly higher level of NK cells in peripheral blood compared to controls (p < 0.001). Furthermore, increased IFN -, while decreased IL-10 serum levels were observed in children with ADHD compared to their control group. In conclusion our findings suggested that children with ADHD may have impaired immune responses, as NK cells were increased in peripheral blood compared to the control group. Also, the serum level of IFN - was higher, while the serum level of IL-10 was lower in ADHD children as compared to controls.