Exploratory study of plasma GFAP and GAD65-Ab levels in children with ADHD

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder in children of school age. In mice with ADHD, glial fibrillary acidic protein (GFAP) levels were significantly higher, whereas glutamic acid decarboxylase 65 (GAD65) levels were lower. The goal of this study is to look at the potential function of GFAP and GAD65 antibodies (GAD65-Ab) in mice and children with ADHD by assessing GFAP and GAD65-Ab levels in the blood. An ADHD model was established in pregnant mice with 15 mg/kg of S-ketamine administration using intraperitoneal injection for 5 days from G14 to G18. Children were enrolled if they met in ADHD Rating Scale (ARS) in Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria for ADHD based on clinical interviews. Venous blood was obtained from children and mice under aseptic conditions and the serum was centrifuged and preserved. Clear supernatants from mice and children were processed simultaneously in duplicate, side by side, for ELISA assay with the calibrators supplied in the GFAP and GAD65-Ab kit. In mice with ADHD-like behaviors, there was a strong positive connection between serum GFAP levels and open-arm times in the elevated plus maze, which corresponded with the association between serum GFAP levels and hyperactivity-impulsivity ratings (r [Spearman] = 0.496, P = 0.004). The optimal cut-off value of serum GFAP levels as an indicator for auxiliary diagnosis of ADHD was projected to be 28.8 ng/ml based on the receiver operating characteristic (ROC) curve, yielding a sensitivity of 28.6% and a specificity of 100%; the area under the curve was 0.7221 (95% CI, 0.5553–0.8889; P = 0.0214). Additionally, we discovered that in mice exhibiting ADHD-like behaviors, a reduction in context-related freezing time was connected to an increase in blood GAD65-Ab levels. With an ideal cut-off value of 9.2 ng/ml (sensitivity, 77.3%; specificity, 88.4%; Area Under the Curve (AUC), 0.7044; 95%CI, 0.5336–0.8752; P = 0.0342), there was a striking link between inattention scores and serum GAD65-Ab levels (P = 0.0336; r [Pearson] = 0.486, P = 0.048). The data support the theory that elevated blood levels of GFAP and GAD65-Ab may be involved in the pathophysiology of ADHD in children and that these levels may be correlated with the severity of ADHD in children. Name of the registry: The study of the accuracy and specificity of glial fibrillary acid protein (GFAP) combined with glutamate decarboxylase autoantibody GAD-Ab in the diagnosis of Attention Hyperactivity Deficit Hyperactivity Disorder (ADHD). Trial registration number: ChiCTR2300068366. Date of registration: 02/16/2023. URL of trial registry record: https://www.chictr.org.cn/index.html.