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. 2014 Apr 28:10:14.
doi: 10.1186/1744-9081-10-14.

A key role for an impaired detoxification mechanism in the etiology and severity of autism spectrum disorders

Altaf Alabdali, Laila Al-Ayadhi, Afaf El-Ansary  1
Affiliations

A key role for an impaired detoxification mechanism in the etiology and severity of autism spectrum disorders

Altaf Alabdali et al. Behav Brain Funct. .

Abstract

Background: Autism Spectrum Disorders (ASD) is a syndrome with a number of etiologies and different mechanisms that lead to abnormal development. The identification of autism biomarkers in patients with different degrees of clinical presentation (i.e., mild, moderate and severe) will give greater insight into the pathogenesis of this disease and will enable effective early diagnostic strategies and treatments for this disorder.

Methods: In this study, the concentration of two toxic heavy metals, lead (Pb) and mercury (Hg), were measured in red blood cells, while glutathione-s-transferase (GST) and vitamin E, as enzymatic and non-enzymatic antioxidants, respectively, were measured in the plasma of subgroups of autistic patients with different Social Responsiveness Scale (SRS) and Childhood Autism Rating Scale (CARS) scores. The results were compared to age- and gender-matched healthy controls.

Results: The obtained data showed that the patients with autism spectrum disorder had significantly higher Pb and Hg levels and lower GST activity and vitamin E concentrations compared with the controls. The levels of heavy metals (Hg and Pb), GST and vitamin E were correlated with the severity of the social and cognitive impairment measures (SRS and CARS). Receiver Operating Characteristics (ROC) analysis and predictiveness curves indicated that the four parameters show satisfactory sensitivity, very high specificity and excellent predictiveness. Multiple regression analyses confirmed that higher levels of Hg and Pb, together with lower levels of GST and vitamin E, can be used to predict social and cognitive impairment in patients with autism spectrum disorders.

Conclusion: This study confirms earlier studies that implicate toxic metal accumulation as a consequence of impaired detoxification in autism and provides insight into the etiological mechanism of autism.

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Figures

Figure 1
Figure 1
Mean levels of A) mercury (μg/L), B) lead (μg/L), C) GST (μmol/min/ml) and D) vitamin E (nmol/L) of the autistic groups compared with age- and sex-matched controls. The mean value for each group is designated by a line.
Figure 2
Figure 2
Percentage change of A) mercury, B) lead, C) GST and D) vitamin E in the autistic group relative to the control group, which is represented as 100%.
Figure 3
Figure 3
ROC-curves for A) mercury, B) lead, C) GST and D) vitamin E in the autistic groups.
Figure 4
Figure 4
Predictiveness curve for A) mercury, B) lead, C) GST and D) vitamin E in the autistic patients.
See this image and copyright information in PMC

References

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