Diagnostic and severity correlation of serum zinc, copper, and anti-myelin basic protein antibodies in children with autism spectrum disorder: a cross-sectional controlled study

Abstract Background Recent evidence has linked the pathophysiology of autism spectrum disorder (ASD) to immune dysregulation, oxidative stress, and imbalances in trace elements, particularly zinc and copper. Elevated levels of anti-myelin basic protein (anti-MBP) antibodies may also reflect an autoimmune component in ASD. The roles of these biomarkers in oxidative stress regulation, neuronal development, and immune-mediated myelin damage suggest their contribution to the pathophysiology of ASD. Objective This cross-sectional controlled study aimed to compare serum levels of zinc, copper, and anti-MBP antibodies in children with ASD and healthy controls. It also investigated the association between these biomarkers and the severity of ASD, and their potential use in supporting diagnosis. Methods Thirty children diagnosed with ASD were enrolled in this study along with 30 healthy age- and sex-matched controls. Serum levels of zinc, copper, and anti-MBP antibodies were measured in both groups for comparison. Severity of ASD was assessed using the Childhood Autism Rating Scale (CARS). All biomarkers were correlated to ASD severity. Results Children with ASD had significantly lower serum zinc levels (mean ± SD = 60.10 ± 2.26 µg per deciliter [µg/dL] vs. 77.50 ± 10.20 µg/dL), higher copper levels (mean ± SD = 192.60 ± 6.83 µg/dL vs. 99.17 ± 14.58 µg/dL), and higher anti-MBP antibody levels (mean ± SD = 11.59 ± 8.55 nanograms per milliliter [ng/mL] vs. 3.44 ± 1.34 ng/mL) compared to controls ( p -value < 0.001). ROC analysis demonstrated strong diagnostic performance for zinc (area under the curve [AUC] = 92.9%; optimal cutoff: ≤ 59 µg/dL), copper (AUC = 99.6%; cutoff: ≥ 121 µg/dL), and anti-MBP antibodies (AUC = 99.4%; cutoff: ≥ 3.94 ng/mL). Significant correlations were found between CARS scores and serum zinc ( r = –0.460, p -value = 0.010), copper ( r = 0.533, p -value = 0.002), the zinc/copper ratio ( r = –0.518, p -value = 0.003), and anti-MBP antibody levels ( r = 0.505, p -value = 0.004). Conclusions Children with ASD showed significantly lower zinc, higher copper levels, and elevated anti-MBP antibodies. These biomarkers could serve as possible diagnostic indicators or therapeutic targets in ASD management. The results suggest a correlation between these biomarkers and the severity of ASD. Larger studies are warranted to validate these findings.