A randomised, controlled study of dietary intervention in autistic syndromes

Intestinal lymphocyte populations in children with regressive autism: evidence for extensive mucosal immunopathology

Inflammatory intestinal pathology has been reported in children with regressive autism (affected children). Detailed analysis of intestinal biopsies in these children indicates a novel lymphocytic enterocolitis with autoimmune features; however, links with cognitive function remain unclear. To characterize further, the nature and extent of this disease we examined the mucosal infiltrate using flow cytometry. Duodenal, ileal, and colonic biopsies were obtained from 52 affected children, 25 histologically normal, and 54 histologically inflamed, developmentally normal controls. Epithelial and lamina propria lymphocyte populations were isolated and examined by multicolor flow cytometry. Adjacent biopsies were assessed by semiquantitative histopathology. At all sites, CD3(+) and CD3(+)CD8(+) IEL as well as CD3(+) LPL were significantly increased in affected children compared with developmentally normal noninflamed control groups (p<0.01) reaching levels similar to inflamed controls. In addition, two populations--CD3(+)CD4(+) IEL and LP CD19(+) B cells--were significantly increased in affected children compared with both noninflamed and inflamed control groups including IBD, at all sites examined (p<0.01). Histologically there was a prominent mucosal eosinophil infiltrate in affected children that was significantly lower in those on a gluten- and casein-free diet, although lymphocyte populations were not influenced by diet. The data provide further evidence of a pan-enteric mucosal immunopathology in children with regressive autism that is apparently distinct from other inflammatory bowel diseases.

Focal-enhanced gastritis in regressive autism with features distinct from Crohn's and Helicobacter pylori gastritis

BACKGROUND

Immunohistochemistry allowed recent recognition of a distinct focal gastritis in Crohn's disease. Following reports of lymphocytic colitis and small bowel enteropathy in children with regressive autism, we aimed to see whether similar changes were seen in the stomach. We thus studied gastric antral biopsies in 25 affected children, in comparison to 10 with Crohn's disease, 10 with Helicobacter pylori infection, and 10 histologically normal controls. All autistic, Crohn's, and normal patients were H. pylori negative.

METHODS

Snap-frozen antral biopsies were stained for CD3, CD4, CD8, gammadelta T cells, HLA-DR, IgG, heparan sulphate proteoglycan, IgM, IgA, and C1q. Cell proliferation was assessed with Ki67.

RESULTS

Distinct patterns of gastritis were seen in the disease states: diffuse, predominantly CD4+ infiltration in H. pylori, and focal-enhanced gastritis in Crohn's disease and autism, the latter distinguished by striking dominance of CD8+ cells, together with increased intraepithelial lymphocytes in surface, foveolar and glandular epithelium. Proliferation of foveolar epithelium was similarly increased in autism, Crohn's disease and H. pylori compared to controls. A striking finding, seen only in 20/25 autistic children, was colocalized deposition of IgG and C1q on the subepithelial basement membrane and the surface epithelium.

CONCLUSIONS

These findings demonstrate a focal CD8-dominated gastritis in autistic children, with novel features. The lesion is distinct from the recently recognized focal gastritis of Crohn's disease, which is not CD8-dominated. As in the small intestine, there is epithelial deposition of IgG.

Gluten- and casein-free diets for autistic spectrum disorder

BACKGROUND

It has been suggested that peptides from gluten and casein may have a role in the origins of autism and that the physiology and psychology of autism might be explained by excessive opioid activity linked to these peptides. Research has reported abnormal levels of peptides in the urine and cerebrospinal fluid of persons with autism. If this is the case, diets free of gluten and /or casein should reduce the symptoms associated with autism.

OBJECTIVES

To determine the efficacy of gluten- and/or casein- free diets as an intervention to improve behaviour, cognitive and social functioning in individuals with autism.

SEARCH STRATEGY

Electronic searching of abstracts from the Cochrane Library (Issue 3, 2003), PsycINFO (1971- May 2003), EMBASE (1974- May 2003), CINAHL (1982- May 2003), MEDLINE (1986- May 2003), ERIC (1965-2003), LILACS (to 2003) and the specialist register of the Cochrane Complementary Medicine Field (January 2004). Review bibliographies were also examined to identify potential trials.

SELECTION CRITERIA

All randomised controlled trials involving programmes which eliminated gluten, casein or both gluten and casein from the diets of individuals diagnosed with autistic spectrum disorder.

DATA COLLECTION AND ANALYSIS

Abstracts of studies identified in searches of electronic databases were read and assessed to determine whether they might meet the inclusion criteria. The authors independently selected the relevant studies from the reports identified in this way. As only one trial fitted the inclusion criteria, no meta-analysis is currently possible and data are presented in narrative form.

MAIN RESULTS

The one trial included reported results on four outcomes. Unsurprisingly in such a small-scale study, the results for three of these outcomes (cognitive skills, linguistic ability and motor ability) had wide confidence intervals that spanned the line of nil effect. However, the fourth outcome, reduction in autistic traits, reported a significant beneficial treatment effect for the combined gluten- and casein- free diet.

REVIEWERS' CONCLUSIONS

This is an important area of investigation and large scale, good quality randomised controlled trials are needed.

Use of complementary and alternative treatments for children with autistic spectrum disorders is increasing

Interventions considered to be CAM are in constant flux. New treatments emerge, older treatments become less popular, and the cycle recurs. Data supporting new treatments should be scrutinized for scientific study design, clinical safety, and scientific validity. Many families approach the clinician armed with brochures, handouts, and printouts from Web sites that are dedicated to the care and support of parents and children with ASD. A recent web search using "autism and detoxification" resulted in almost 8,000 sites. The Defeat Autism Now! (DAN!) Project arose in 1995 from collaboration of members of the Autism Research Institute. The DAN! Project advocates a specific and extensive protocol for diagnosis and treatment and can be viewed at http://www.autism.com/ari/#dan. The scientific validation and support for many interventions is incomplete and disparate from the recommendation in the American Academy of Pediatrics Policy Statement. Families should be encouraged to discuss all proposed investigations or treatments they wish to try with their primary care provider so the practitioner can serve as the medical home (Sidebar, page 688). The clinician should communicate and collaborate with the family and educational professionals to encourage objective identification of what works. With increasing access to health information and societal pressure for families to actively participate in their health management, continued growth of interest in CAM can be anticipated. Clinicians must remember that parents may have different beliefs regarding the effectiveness of treatment and different tolerance for treatment risks. Practitioners must keep avenues of communication open, remain open-minded, and not assume a "don't ask, don't tell" posture in the context of providing a medical home to the increasing number of children diagnosed with autism.

Can the pathophysiology of autism be explained by the nature of the discovered urine peptides?

Opioid peptides derived from food proteins (exorphins) have been found in urine of autistic patients. Based on the work of several groups, we try to show that exorphins and serotonin uptake stimulating factors may explain many of the signs and symptoms seen in autistic disorders. The individual symptoms ought to be explainable by the properties and behavioural effects of the found peptides. The data presented form the basis of an autism model, where we suggest that exorphins and serotonin uptake modulators are key mediators for the development of autism. This may be due to a genetically based peptidase deficiency in at least two or more peptidases and, or of peptidase regulating proteins made manifest by a dietary overload of exorphin precursors such as by increased gut uptake.

Findings in normal rats following administration of gliadorphin-7 (GD-7)

This paper discusses the effects of gliadorphin-7 (GD-7) infusion in rats and contrasts them with those of beta-casomorphin-7 (betaC-7). Both induce FLI in a dose related fashion. Very strong expression in both geniculate nuclei (GN) and the alveus hippocampus follow GD-7 400 microgram and betaC-7 30 microgram/kg BW. GD-7 affects only these three regions while betaC-7affects 45. FLI is prevented by Naloxone 2mg/kg BW in all regions except the GN where it is diminished 60%. betaC-7 causes bizarre behavior beginning 60s after infusion is started. GD-7 causes no behavioral change. These findings suggest GD-7 gains access to brain cells by diffusion through circumventricular organs while betaC-7 passes the BBB by carrier facilitation.