Assessment of Serum Levels of Zinc and Copper in Children with Autism Spectrum Disorders: Relation to Anti-Myelin-Basic Protein Brain-Specific Antibodies

Abstract

Abstract Background Heavy metals include arsenic, cadmium, chromium, copper, lead, nickel, and zinc, all of which cause risks for human health and the environment. Zn and Cu are important trace elements necessary for the proper functioning of neurons. Impaired zinc and/or copper metabolism and signaling are implicated in many brain diseases, including autism. Cu in normal levels is essential for optimal health, cell metabolism, and oxidation-reduction reaction. Autoimmunity to CNS may have a pathogenic role in autism. This may be indicated by the presence of brain-specific auto-antibodies in some autistic children. There is also an increase in the frequency of autoimmune disorders among autistic families. Aim of the Work First objective: The correlation between levels of anti-myelin-basic protein brain specific antibodies and both zinc and copper in autistic children. Second objective: The relationship between these results and the degree of severity of autism spectrum disorder will be studied. Patients and Methods This study was designed to be a pilot cross section study. It was conducted at the Department of Pediatrics, Children's Hospital, Faculty of Medicine, Ain Shams University over a period of 6 months. Thirty autistic children (Group A) were recruited from the Developmental and Behavioral Pediatric Clinic, Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt, during their follow up visits. The control group (Group B) comprised 30 age- and sex- matched apparently healthy children. They were recruited from the Outpatients Clinic, Children's Hospital, Faculty of Medicine, Ain Shams University. The control children were not related to the children with autism, and demonstrated no clinical findings suggestive of infections, allergic manifestations and immunological or neuropsychiatric disorders.serum levels of copper and zinc measured by Atomic Absorption for case and control and also serum levels of anti-myelin-basic protein brain specific antibodies measured by human ELISA. The degree of the disease severity was assessed by using the Childhood Autism Rating Scale (CARS). Results this study had revealed that Group A had significantly lower zinc levels Mean±SD(60.10±2.26) µ/dL compared to Group B (77.5±10.20) µ/dL, higher copper levels (192.60±6.83) µ/dL compared to Group B (99.17±14.58) µ/dL and higher levels of antimyelin-basic protein antibody (11.59±8.55) ng/mL compared to Group B (3.44±1.34) ng/mL. These differences are highly significant (p < 0.001**), indicating distinct serum profiles between the two groups. Also Zn /Cu ratio was lower in cases group(0.797 ± 0.157) than control group (0.313 ± 0.019)with highly significant P value (0,001). Also the study had revealed that there was negative correlation between CARS(Childhood Autism Rating Scale) Score and low serum zinc level, of statistical significance (p = 0.005). and there was positive correlation between CARS Score and high serum copper level, of statistical significance (p = 0.012)Also, there was positive correlation between CARS Score and antimyelin basic protein antibody was statistically significant (p = 0.001). Also The correlation between serum zinc levels and serum antibody levels was not statistically significant (p = 0.459), Similarly, the correlation between copper and antimyelin basic protien antibody is not statistically significant (p = 0.926). Conclusion Our findings suggest that elevated serum levels of copper, low serum levels of zinc and elevated levels of antimyelin basic protein are associated with autism.