الفهرس 
AUTISMOnly 14 pages are availabe for public view
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Abstract
Autism is a complex developmental disorder diagnosed on the basis of behavioral symptoms that typically appear during the first 3 years of life. Autism is one of five coming under the umbrella of pervasive developmental disorders (PDDs) or autistic spectrum disorders (ASDs). Children with autism typically have difficulties in verbal and non-verbal communication, social interactions, and leisure or play activities. The prevalence of autism is 1 case per 500 in USA, but cases of autism are increasing.
Gastrointestinal symptoms are reported to be more common in children with ASDs although this is somewhat controversial. Many parents observe that the onset of gastrointestinal symptoms coincides with early concerns about their infant’s development. In the leaky gut opioid-excess theory, it is proposed that increased intestinal permeability in children leads to increased absorption of dietary peptides, which ultimately leads to disruption of neuroregulatory mechanisms and normal brain development.
The measuring of passive permeability using the dual sugar technique; lactulose and mannitol; may be the most useful and precise non-invasive method for assessing mucosal integrity in the small bowel. Mannitol; a monosaccharide; and lactulose; a disaccharide are water soluble molecules that are not metabolized by the body. Hence, our aim of the present work was to detect the increased intestinal permeability in autistic children by using the convenient and non-invasive lactulose/mannitol test which assesses mucosal integrity of the small bowel in children as well as its relation to the severity of the disease. This study was conducted on 50 children with autism diagnosed according to DSM-IV. They were compared to 20 age- and sex-matched healthy controls. The autistic children were subclassified according to the severity of autism using CARS classification into 38 children with mild to moderate degree of autism and 12 children with severe degree of autism.
Urinary mannitol and lactulose concentrations was measured using HPLC and the results were expressed as lactulose recovery % (concentration of lactulose in urine/amount of lactulose ingested x 100), mannitol recovery % (concentration of mannitol in urine/amount of mannitol ingested x 100) and L/M recovery ratio (lactulose recovery % / mannitol recovery %).
Our results revealed a highly significant elevation of both lactulose recovery % and L/M recovery ratio in autistic children when compared to healthy controls. On the other hand, mannitol recovery % didn’t show a statistically significant difference between the two groups.
Diagnostic performance study using Receiver Operating Characteristic (ROC) curve analysis was done for lactulose recovery % and L/M recovery ratio in an attempt to determine the best cut-off value for each one that helps in assessment of the increased intestinal permeability in all autistic patients versus healthy control group. It revealed that the best cut-off value for lactulose recovery % was 2.6% at which the diagnostic sensitivity was 92%, diagnostic specificity 100%, positive predictive value 100%, negative predictive value 83% and diagnostic efficacy 94%. While the best cut-off for L/M recovery ratio was 0.5 at which the diagnostic sensitivity was 96%, diagnostic specificity 90%, positive predictive value 96%, negative predictive value 90% and diagnostic efficacy 94%.
As regard the relation of intestinal permeability to the severity of the disease. Both lactulose recovery % and L/M recovery ratio showed significant elevation in each of mild to moderate and severe autistic patients groups in relation to the controls. In addition, L/M recovery ratio was significantly higher in severe autistic patients when compared to mild to moderate ones.