Family Forum / Parenting / Children's Health / February 2009

Autism and Gastrointestinal Pathology
http://www.autism.com/medical/research/advances/autism-gastro.htm

1a. Intestinal pathophysiology in autism

White JF.
Exp Biol Med (Maywood). 2003 Jun;228(6):639-49.
http://www.ebmonline.org/cgi/content/full/228/6/639

[An excellent overview, with a section on intestinal permeability,
another on vaccines including the MMR. White's essay gives perspective
to contrary findings such as those in cites 2 and 3 hereinbelow.]

Autism is a life-long developmental disorder affecting as many as 1 in
500 children. The causes for this profound disorder are largely
unknown. Recent research has uncovered pathology in the
gastrointestinal tract of autistic children. The pathology, reported
to extend from the esophagus to the colon, is described here along
with other studies pointing to a connection between diet and the
severity of symptoms expressed in autism. The evidence that there is
impaired intestinal permeability in autism is reviewed, and various
theories are discussed by which a leaky gut could develop. Lastly,
some possible ways in which impaired gastrointestinal function might
influence brain function are discussed.
   PMID: 12773694

1b. Autism Spectrum Disorders: Concurrent Clinical Disorders

Ming X et al.
Journal of Child Neurology, Vol. 23, No. 1, 6-13 (2008)
http://jcn.sagepub.com/cgi/content/abstract/23/1/6

Individuals with autism spectrum disorder are heterogeneous in
clinical presentation, concurrent disorders, and developmental
outcomes. This study characterized the clinical co-occurrences and
potential subgroups in 160 children with autism spectrum disorders who
presented to The Autism Center between 1999 and 2003. Medical and
psychiatric co-occurrences included sleep disorders, epilepsy, food
intolerance, gastrointestinal dysfunction, mood disorder, and
aggressive and self-injurious behaviors. Sleep disorders were
associated with gastrointestinal dysfunction (P < .05) and mood
disorders (P < .01). Food intolerance was associated with
gastrointestinal dysfunction (P = .001). Subjects with mood disorder
tended to develop aggressive or self-injurious behaviors (P < .05).
Developmental regression was not associated with increased co-
occurrence of medical or psychiatric disorders. Medical co-occurrence
did not present as a risk factor for psychiatric co-occurrence, and
vice versa. These results showed a high prevalence of multiple medical
and psychiatric co-occurrences. There may be common pathophysiologic
mechanisms resulting in clinical subgroups of autism spectrum
disorders. Recognition of the co-occurrence of concurrent disorders
may provide insight into the therapeutic strategy.

2. Abnormal intestinal permeability in children with autism

D'Eufemia P et al.
Acta Paediatr. 1996 Sep;85(9):1076-9.

We determined the occurrence of gut mucosal damage using the
intestinal permeability test in 21 autistic children who had no
clinical and laboratory findings consistent with known intestinal
disorders. An altered intestinal permeability was found in 9 of the 21
(43%) autistic patients, but in none of the 40 controls. Compared to
the controls, these nine patients showed a similar mean mannitol
recovery, but a significantly higher mean lactulose recovery (1.64%
+/- 1.43 vs 0.38% +/- 0.14; P < 0.001). We speculate that an altered
intestinal permeability could represent a possible mechanism for the
increased passage through the gut mucosa of peptides derived from
foods with subsequent behavioural abnormalities.
   PMID: 8888921

3. Intestinal Permeability and Glucagon-like peptide-2 in Children
with Autism: A Controlled Pilot Study

Robertson MA et al.
J Autism Dev Disord. 2008 Feb 29 [Epub ahead of print]

We measured small intestinal permeability using a lactulose:mannitol
sugar permeability test in a group of children with autism, with
current or previous gastrointestinal complaints. Secondly, we examined
whether children with autism had an abnormal glucagon-like peptide-2
(GLP-2) response to feeding. Results were compared with sibling
controls and children without developmental disabilities. We enrolled
14 children with autism, 7 developmentally normal siblings of these
children and 8 healthy, developmentally normal, unrelated children.
Our study did not detect differences in these measures of
gastrointestinal function in a group of children with autism.
   PMID: 18311517

4. Polymorphism of bovine beta-casein and its potential effect on
human health

Stanislaw Kaminski, Anna Cieslinska, Elzbieta Kostyra
Journal of Applied Genetics 48(3),2007, pp. 189 - 198
http://jag.igr.poznan.pl/2007-Volume-48/3/pdf/2007_Volume_48_3-189-198.pdf

Proteins in bovine milk are a common source of bioactive peptides. The
peptides are released by the digestion of caseins and whey proteins.
In vitro the bioactive peptide beta-casomorphin 7 (BCM-7) is yielded
by the successive gastrointestinal proteolytic digestion of bovine
beta-casein variants A1 and B, but this was not seen in variant A2. In
hydrolysed milk with variant A1 of beta-casein, BCM-7 level is 4-fold
higher than in A2 milk. Variants A1 and A2 of beta-casein are common
among many dairy cattle breeds. A1 is the most frequent in Holstein-
Friesian (0.310-0.660), Ayrshire (0.432-0.720) and Red (0.710) cattle.
In contrast, a high frequency of A2 is observed in Guernsey
(0.880-0.970) and Jersey (0.490-0.721) cattle. BCM-7 may play a role
in the aetiology of human diseases. Epidemiological evidence from New
Zealand claims that consumption of beta-casein A1 is associated with
higher national mortality rates from ischaemic heart disease. It seems
that the populations that consume milk containing high levels of beta-
casein A2 have a lower incidence of cardiovascular disease and type 1
diabetes. BCM-7 has also been suggested as a possible cause of sudden
infant death syndrome. In addition, neurological disorders, such as
autism and schizophrenia, seem to be associated with milk consumption
and a higher level of BCM-7. Therefore, careful attention should be
paid to that protein polymorphism, and deeper research is needed to
verify the range and nature of its interactions with the human
gastrointestinal tract and whole organism.
   PMID: 17666771

5. Relationship of dietary intake to gastrointestinal symptoms in
children with autistic spectrum disorders

Levy SE et al.
Biol Psychiatry. 2007 Feb 15;61(4):492-7.

BACKGROUND: Gastrointestinal (GI) symptoms and abnormalities in stool
consistency are frequently reported by parents of children with autism
spectrum disorders (ASD). The purpose of this study was to 1) describe
dietary intake of a cohort of children with ASD compared with
normative data and 2) determine whether GI symptoms and stool
consistency are related to dietary intake. METHODS: Data from diet
diaries of children (3-8 years) with ASD (n = 62) were analyzed by a
registered pediatric dietician to compare to RDA standards for total
calories, protein, carbohydrate, and fat. Dietary intake was
correlated with descriptors of stool consistency using cumulative
logistic regression methods. RESULTS: Intake of calories,
carbohydrates, and fat were in the average range; protein intake was
increased (211% of RDA). Reported frequency of GI abnormalities,
including abnormal stool consistency (e.g., bulky or loose), was
increased (54%). No statistically significant relationships between
stool consistency and dietary intake were observed. CONCLUSIONS: In
this sample, there was a high rate of reported gastrointestinal
symptoms, despite lack of medical causes. Intake was adequate for
calories and carbohydrates and increased for protein. The children did
not exhibit excessive carbohydrate intake. There was no association of
nutrient intake to changes in stool consistency.
   PMID: 17207470

6. Health implications of milk containing beta-casein with the A2
genetic variant

Bell SJ, Grochoski GT, Clarke AJ.
Crit Rev Food Sci Nutr. 2006;46(1):93-100.

Milk from dairy cows has long provided a high quality source of
protein and selected micronutrients such as calcium to most
populations. Recently, a relationship between disease risk and
consumption of a specific bovine ss-casein fraction either A1 or A2
genetic variants has been identified. Populations, which consume milk
containing high levels of ss-casein A2 variant, have a lower incidence
of cardiovascular disease and type 1 diabetes. Furthermore,
consumption of milk with the A2 variant may be associated with less
severe symptoms of autism and schizophrenia. The mechanism of action
focuses on ss-casein A1 and related forms preferentially that are able
to produce a bioactive opioid peptide, ss-casomorphin-7 (ss-CM-7)
during digestion. Infants may absorb ss-CM-7 due to an immature
gastrointestinal tract. Adults, on the other hand, appear to reap the
biological activity locally on the intestinal brush boarder. ss-CM-7
can potentially affect numerous opioid receptors in the nervous,
endocrine, and immune systems. Whether there is a definite health
benefit to milk containing the A2 genetic variant is unknown and
requires further investigation.
   PMID: 16403684

7. Evaluation of an association between gastrointestinal symptoms and
cytokine production against common dietary proteins in children with
autism spectrum disorders

Jyonouchi H et al.
J Pediatr. 2005 May;146(5):605-10.

OBJECTIVE: To evaluate an association between cytokine production with
common dietary proteins as a marker of non-allergic food
hypersensitivity (NFH) and gastrointestinal (GI) symptoms in young
children with autism spectrum disorders (ASD). STUDY DESIGN:
Peripheral blood mononuclear cells (PBMCs) were obtained from 109 ASD
children with or without GI symptoms (GI [+] ASD, N = 75 and GI (-)
ASD, N = 34], from children with NFH (N = 15), and control subjects (N
= 19). Diarrhea and constipation were the major GI symptoms. We
measured production of type 1 T-helper cells (Th1), type 2 T-helper
cells (Th2), and regulatory cytokines by PBMCs stimulated with whole
cow's milk protein (CMP), its major components (casein, beta-
lactoglobulin, and alpha-lactoalbumin), gliadin, and soy. RESULTS:
PBMCs obtained from GI (+) ASD children produced more tumor necrosis
factor-alpha (TNF-alpha)/interleukin-12 (IL-12) than those obtained
from control subjects with CMP, beta-lactoglobulin, and alpha-
lactoalbumin, irrespective of objective GI symptoms. They also
produced more TNF-alpha with gliadin, which was more frequently
observed in the group with loose stools. PBMCs obtained from GI (-)
ASD children produced more TNF-alpha/IL-12 with CMP than those from
control subjects, but not with beta-lactoglobulin, alpha-lactoalbumin,
or gliadin. Cytokine production with casein and soy were unremarkable.
CONCLUSION: A high prevalence of elevated TNF-alpha/IL-12 production
by GI (+) ASD PBMCs with CMP and its major components indicates a role
of NFH in GI symptoms observed in children with ASD.
   PMID: 15870662

8. Dysregulated innate immune responses in young children with autism
spectrum disorders: their relationship to gastrointestinal symptoms
and dietary intervention

Jyonouchi H et al.
Neuropsychobiology. 2005;51(2):77-85.

OBJECTIVE: Our previous study indicated an association between
cellular immune reactivity to common dietary proteins (DPs) and
excessive proinflammatory cytokine production with endotoxin
(lipopolysaccharide, LPS), a major stimulant of innate immunity in the
gut mucosa, in a subset of autism spectrum disorder (ASD) children.
However, it is unclear whether such abnormal LPS responses are
intrinsic in these ASD children or the results of chronic
gastrointestinal (GI) inflammation secondary to immune reactivity to
DPs. This study further explored possible dysregulated production of
proinflammatory and counter-regulatory cytokines with LPS in ASD
children and its relationship to GI symptoms and the effects of
dietary intervention measures. METHODS: This study includes ASD
children (median age 4.8 years) on the unrestricted (n = 100) or
elimination (n = 77) diet appropriate with their immune reactivity.
Controls include children with non-allergic food hypersensitivity
(NFH; median age 2.9 years) on the unrestricted (n = 14) or
elimination (n = 16) diet, and typically developing children (median
age 4.5 years, n = 13). The innate immune responses were assessed by
measuring production of proinflammatory (TNF-alpha, IL-1beta, IL-6,
and IL-12) and counter-regulatory (IL-1ra, IL-10, and sTNFRII)
cytokines by peripheral blood mononuclear cells (PBMCs) with LPS. The
results were also compared to T-cell responses with common DPs and
control T-cell mitogens assessed by measuring T-cell cytokine
production. RESULTS: ASD and NFH PBMCs produced higher levels of TNF-
alpha with LPS than controls regardless of dietary interventions.
However, only in PBMCs from ASD children with positive
gastrointestinal (GI(+)) symptoms, did we find a positive association
between TNF-alpha levels produced with LPS and those with cow's milk
protein (CMP) and its major components regardless of dietary
interventions. In the unrestricted diet group, GI(+) ASD PBMCs
produced higher IL-12 than controls and less IL-10 than GI(-) ASD
PBMCs with LPS. GI(+) ASD but not GI(-) ASD or NFH PBMCs produced less
counter-regulatory cytokines with LPS in the unrestricted diet group
than in the elimination diet group. There was no significant
difference among the study groups with regard to cytokine production
in responses to T-cell mitogens and other recall antigens. Conclusion:
Our results revealed that there are findings limited to GI(+) ASD
PBMCs in both the unrestricted and elimination diet groups. Thus our
findings indicate intrinsic defects of innate immune responses in GI
(+) ASD children but not in NFH or GI(-) ASD children, suggesting a
possible link between GI and behavioral symptoms mediated by innate
immune abnormalities. Copyright 2005 S. Karger AG, Basel.
   PMID: 15741748

9. Innate immunity associated with inflammatory responses and cytokine
production against common dietary proteins in patients with autism
spectrum disorder

Jyonouchi H, Sun S, Itokazu N.
Neuropsychobiology. 2002;46(2):76-84.

   OBJECTIVES: Children with autism spectrum disorder (ASD)
frequently reveal various gastrointestinal (GI) symptoms that may
resolve with an elimination diet along with apparent improvement of
some of the behavioral symptoms. Evidence suggests that ASD may be
accompanied by aberrant (inflammatory) innate immune responses. This
may predispose ASD children to sensitization to common dietary
proteins (DP), leading to GI inflammation and aggravation of some
behavioral symptoms. METHODS: We measured IFN-gamma, IL-5, and TNF-
alpha production against representative DPs [gliadin, cow's milk
protein (CMP), and soy] by peripheral blood mononuclear cells (PBMCs)
from ASD and control children [those with DP intolerance (DPI), ASD
siblings, and healthy unrelated children]. We evaluated the results in
association with proinflammatory and counter-regulatory cytokine
production with endotoxin (LPS), a microbial product of intestinal
flora and a surrogate stimulant for innate immune responses. RESULTS:
ASD PBMCs produced elevated IFN-gamma and TNF-alpha, but not IL-5 with
common DPs at high frequency as observed in DPI PBMCs. ASD PBMCs
revealed increased proinflammatory cytokine responses with LPS at high
frequency with positive correlation between proinflammatory cytokine
production with LPS and IFN-gamma and TNF-alpha production against
DPs. Such correlation was less evident in DPI PBMCs. CONCLUSION:
Immune reactivity to DPs may be associated with apparent DPI and GI
inflammation in ASD children that may be partly associated with
aberrant innate immune response against endotoxin, a product of the
gut bacteria. Copyright 2002 S. Karger AG, Basel
   PMID: 12378124

10. Real-time PCR quantitation of clostridia in feces of autistic
children

Song Y, Liu C, Finegold SM.
Appl Environ Microbiol. 2004 Nov;70(11):6459-65.
http://aem.asm.org/cgi/content/full/70/11/6459?view=long&pmid=15528506

Based on the hypothesis that intestinal clostridia play a role in late-
onset autism, we have been characterizing clostridia from stools of
autistic and control children. We applied the TaqMan real-time PCR
procedure to detect and quantitate three Clostridium clusters and one
Clostridium species, C. bolteae, in stool specimens. Group- and
species-specific primers targeting the 16S rRNA genes were designed,
and specificity of the primers was confirmed with DNA from related
bacterial strains. In this procedure, a linear relationship exists
between the threshold cycle (CT) fluorescence value and the number of
bacterial cells (CFU). The assay showed high sensitivity: as few as 2
cells of members of cluster I, 6 cells of cluster XI, 4 cells of
cluster XIVab, and 0.6 cell of C. bolteae could be detected per PCR.
Analysis of the real-time PCR data indicated that the cell count
differences between autistic and control children for C. bolteae and
the following Clostridium groups were statistically significant: mean
counts of C. bolteae and clusters I and XI in autistic children were
46-fold (P = 0.01), 9.0-fold (P = 0.014), and 3.5-fold (P = 0.004)
greater than those in control children, respectively, but not for
cluster XIVab (2.6 x 10(8) CFU/g in autistic children and 4.8 x 10(8)
CFU/g in controls; respectively). More subjects need to be studied.
The assay is a rapid and reliable method, and it should have great
potential for quantitation of other bacteria in the intestinal tract.
   PMID: 15528506

11. Differences between the gut microflora of children with autistic
spectrum disorders and that of healthy children

Parracho HM, Bingham MO, Gibson GR, McCartney AL.
J Med Microbiol. 2005 Oct;54(Pt 10):987-91.
http://jmm.sgmjournals.org/cgi/content/full/54/10/987

Children with autistic spectrum disorders (ASDs) tend to suffer from
severe gastrointestinal problems. Such symptoms may be due to a
disruption of the indigenous gut flora promoting the overgrowth of
potentially pathogenic micro-organisms. The faecal flora of patients
with ASDs was studied and compared with those of two control groups
(healthy siblings and unrelated healthy children). Faecal bacterial
populations were assessed through the use of a culture-independent
technique, fluorescence in situ hybridization, using oligonucleotide
probes targeting predominant components of the gut flora. The faecal
flora of ASD patients contained a higher incidence of the Clostridium
histolyticum group (Clostridium clusters I and II) of bacteria than
that of healthy children. However, the non-autistic sibling group had
an intermediate level of the C. histolyticum group, which was not
significantly different from either of the other subject groups.
Members of the C. histolyticum group are recognized toxin-producers
and may contribute towards gut dysfunction, with their metabolic
products also exerting systemic effects. Strategies to reduce
clostridial population levels harboured by ASD patients or to improve
their gut microflora profile through dietary modulation may help to
alleviate gut disorders common in such patients.
   PMID: 16157555

12. Therapy and epidemiology of autism--clostridial spores as key
elements

Finegold SM.
Med Hypotheses. 2008;70(3):508-11. Epub 2007 Sep 29.

This manuscript reviews evidence indicating that intestinal bacteria,
specifically clostridia, may play a role in certain cases of autism
and hypothesizes that the clostridial spores (which are notably
resistant to antimicrobial agents and commonly used germicides) are
involved in: (1) relapse in the autistic subject after a response to
an agent such as oral vancomycin, after the drug is discontinued, (2)
the unexplained increased incidence of autism in recent years, and (3)
the unexplained increase in numbers of multiple cases in the same
family. Hypothesis (1), if established as valid, would spur research
to find well-tolerated and safe agents that could be given together
with vancomycin (or other appropriate antimicrobial agent) to
eliminate spores; this would revolutionize the therapeutic approach.
Hypotheses (2) and (3) relate to widespread use of antimicrobial
agents, poor hygiene in young autistic children, and difficulty in
removing spores from the home environment. These latter two hypotheses
have major implications with regard to the epidemiology of this
important and distressing disease and would encourage research into
methods to eliminate clostridial spores from the home and other
environments.
   PMID: 17904761

13. Tight junctions, leaky intestines, and pediatric diseases

Liu Z, Li N, Neu J.
Acta Paediatr. 2005 Apr;94(4):386-93.

BACKGROUND: Tight junctions (TJs) represent the major barrier within
the paracellular pathway between intestinal epithelial cells.
Disruption of TJs leads to intestinal hyperpermeability (the so-called
"leaky gut") and is implicated in the pathogenesis of several acute
and chronic pediatric disease entities that are likely to have their
origin during infancy. AIM: This review provides an overview of
evidence for the role of TJ breakdown in diseases such as systemic
inflammatory response syndrome (SIRS), inflammatory bowel disease,
type 1 diabetes, allergies, asthma, and autism. CONCLUSION: A better
basic understanding of this structure might lead to prevention or
treatment of these diseases using nutritional or other means.
   PMID: 16092447

14. Pilot study of a moderate dose multivitamin/mineral supplement for
children with autistic spectrum disorder

Adams JB, Holloway C.
J Altern Complement Med. 2004 Dec;10(6):1033-9.

OBJECTIVE: Determine the effect of a moderate dose multivitamin/
mineral supplement on children with autistic spectrum disorder.
DESIGN: Randomized, double-blind, placebo-controlled 3-month study.
SUBJECTS: Twenty (20) children with autistic spectrum disorder, ages
3-8 years. RESULTS: A Global Impressions parental questionnaire found
that the supplement group reported statistically significant
improvements in sleep and gastrointestinal problems compared to the
placebo group. An evaluation of vitamin B(6) levels prior to the study
found that the autistic children had substantially elevated levels of
B6 compared to a control group of typical children (75% higher, p <
0.0000001). Vitamin C levels were measured at the end of the study,
and the placebo group had levels that were significantly below average
for typical children, whereas the supplement group had near-average
levels. DISCUSSION: The finding of high vitamin B(6) levels is
consistent with recent reports of low levels of pyridoxal-5-phosphate
and low activity of pyridoxal kinase (i.e., pyridoxal is only poorly
converted to pyridoxal-5-phosphate, the enzymatically active form).
This may explain the functional need for high-dose vitamin B(6)
supplementation in many children and adults with autism.
    PMID: 15673999

15. The significance of ileo-colonic lymphoid nodular hyperplasia in
children with autistic spectrum disorder

Wakefield AJ et al.
Eur J Gastroenterol Hepatol. 2005 Aug;17(8):827-36.

BACKGROUND: Intestinal mucosal pathology, characterized by ileo-
colonic lymphoid nodular hyperplasia (LNH) and mild acute and chronic
inflammation of the colorectum, small bowel and stomach, has been
reported in children with autistic spectrum disorder (ASD). AIM: To
assess ileo-colonic LNH in ASD and control children and to test the
hypothesis that there is an association between ileo-colonic LNH and
ASD in children. PATIENTS AND METHODS: One hundred and forty-eight
consecutive children with ASD (median age 6 years; range 2-16; 127
male) with gastrointestinal symptoms were investigated by ileo-
colonoscopy. Macroscopic and histological features were scored and
compared with 30 developmentally normal (non-inflammatory bowel
disease, non-coeliac disease) controls (median age 7 years; range
1-11; 25 male) showing mild non-specific colitis in 16 cases (13 male)
and normal colonic histology in 14 cases (12 male). Seventy-four ASD
children and 23 controls also underwent upper gastrointestinal
endoscopy. The influence on ileal LNH of dietary restriction, age at
colonoscopy, and co-existent LNH elsewhere in the intestine, was
examined. RESULTS: The prevalence of LNH was significantly greater in
ASD children compared with controls in the ileum (129/144 (90%) vs.
8/27 (30%), P < 0.0001) and colon (88/148 (59%) vs. 7/30 (23%), P =
0.0003), whether or not controls had co-existent colonic inflammation.
The severity of ileal LNH was significantly greater in ASD children
compared with controls, with moderate to severe ileal LNH present in
98 of 144 (68%) ASD children versus 4 of 27 (15%) controls (P <
0.0001). Severe ileal LNH was associated with co-existent colonic LNH
in ASD children (P = 0.01). The presence and severity of ileal LNH was
not influenced by either diet or age at colonoscopy (P = 0.2).
Isolated ileal LNH without evidence of pathology elsewhere in the
intestine was a rare event, occurring in less than 3% of children
overall. On histopathological examination, hyperplastic lymphoid
follicles are significantly more prevalent in the ileum of ASD
children (84/138; 61%) compared with controls (2/23; 9%, P = 0.0001).
CONCLUSION: Ileo-colonic LNH is a characteristic pathological finding
in children with ASD and gastrointestinal symptoms, and is associated
with mucosal inflammation. Differences in age at colonoscopy and diet
do not account for these changes. The data support the hypothesis that
LNH is a significant pathological finding in ASD children.
   PMID: 16003132

16. Spontaneous mucosal lymphocyte cytokine profiles in children with
autism and gastrointestinal symptoms: mucosal immune activation and
reduced counter regulatory interleukin-10

Ashwood P et al.
J Clin Immunol. 2004 Nov;24(6):664-73.

A lymphocytic enterocolitis has been reported in a cohort of children
with autistic spectrum disorder (ASD) and gastrointestinal (GI)
symptoms. This study tested the hypothesis that dysregulated
intestinal mucosal immunity with enhanced pro-inflammatory cytokine
production is present in these ASD children. Comparison was made with
developmentally normal children with, and without, mucosal
inflammation. Duodenal and colonic biopsies were obtained from 21 ASD
children, and 65 developmentally normal paediatric controls, of which
38 had signs of histological inflammation. Detection of CD3+
lymphocyte staining for spontaneous intracellular TNFalpha, IL-2,
IL-4, IFNgamma, and IL-10, was performed by multicolor flow cytometry.
Duodenal and colonic mucosal CD3+ lymphocyte counts were elevated in
ASD children compared with noninflamed controls (p<0.03). In the
duodenum, the proportion of lamina propria (LP) and epithelial CD3(+)
TNFalpha+ cells in ASD children was significantly greater compared
with noninflamed controls (p<0.002) but not coeliac disease controls.
In addition, LP and epithelial CD3(+)IL-2+ and CD3(+)IFNgamma+, and
epithelial CD3(+)IL-4+ cells were more numerous in ASD children than
in noninflamed controls (p<0.04). In contrast, CD3(+)IL-10+ cells were
fewer in ASD children than in noninflamed controls (p<0.05). In the
colon, LP CD3(+)TNFalpha+ and CD3(+)IFNgamma+ were more frequent in
ASD children than in noninflamed controls (p<0.01). In contrast with
Crohn's disease and non-Crohn's colitis, LP and epithelial CD3(+)
IL-10+ cells were fewer in ASD children than in nondisease controls
(p<0.01). There was a significantly greater proportion of CD3(+)
TNFalpha+ cells in colonic mucosa in those ASD children who had no
dietary exclusion compared with those on a gluten and/or casein free
diet (p<0.05). There is a consistent profile of CD3+ lymphocyte
cytokines in the small and large intestinal mucosa of these ASD
children, involving increased pro-inflammatory and decreased
regulatory activities. The data provide further evidence of a diffuse
mucosal immunopathology in some ASD children and the potential for
benefit of dietary and immunomodulatory therapies.
   PMID: 15622451

17. Immune activation of peripheral blood and mucosal CD3+ lymphocyte
cytokine profiles in children with autism and gastrointestinal
symptoms

Ashwood P, Wakefield AJ.
J Neuroimmunol. 2006 Apr;173(1-2):126-34. Epub 2006 Feb 21.

Gastrointestinal pathology, characterized by lymphoid nodular
hyperplasia and entero-colitis, has been demonstrated in a cohort of
children with autistic spectrum disorder (ASD). Systemic and
intestinal mucosal immune dysregulation was assessed in ASD children
with gastrointestinal (GI) symptoms (n = 18), and typically developing
controls (n = 27), including non-inflamed controls (NIC) and inflamed
GI control children with Crohn's disease (CD), by analysis of
intracellular cytokines in CD3+ lymphocytes. In both peripheral blood
and mucosa, CD3+ TNFalpha+ and CD3+ IFNgamma+ were increased in ASD
children compared with NIC (p < 0.004) and reached levels similar to
CD. In contrast, peripheral and mucosal CD3+ IL-10+ were markedly
lower in ASD children with GI symptoms compared with both NIC and CD
controls (p < 0.02). In addition, mucosal CD3+ IL-4+ cells were
increased (p < 0.007) in ASD compared with NIC. There is a unique
pattern of peripheral blood and mucosal CD3+ lymphocytes intracellular
cytokines, which is consistent with significant immune dysregulation,
in this ASD cohort.
   PMID: 16494951

18. Autism spectrum disorders: concurrent clinical disorders

Xue Ming , Brimacombe M, Chaaban J, Zimmerman-Bier B, Wagner GC.
J Child Neurol. 2008 Jan;23(1):6-13. Epub 2007 Dec 3

Individuals with autism spectrum disorder are heterogeneous in
clinical presentation, concurrent disorders, and developmental
outcomes. This study characterized the clinical co-occurrences and
potential subgroups in 160 children with autism spectrum disorders who
presented to The Autism Center between 1999 and 2003. Medical and
psychiatric co-occurrences included sleep disorders, epilepsy, food
intolerance, gastrointestinal dysfunction, mood disorder, and
aggressive and self-injurious behaviors. Sleep disorders were
associated with gastrointestinal dysfunction (P < .05) and mood
disorders (P < .01). Food intolerance was associated with
gastrointestinal dysfunction (P = .001). Subjects with mood disorder
tended to develop aggressive or self-injurious behaviors (P < .05).
Developmental regression was not associated with increased co-
occurrence of medical or psychiatric disorders. Medical co-occurrence
did not present as a risk factor for psychiatric co-occurrence, and
vice versa. These results showed a high prevalence of multiple medical
and psychiatric co-occurrences. There may be common pathophysiologic
mechanisms resulting in clinical subgroups of autism spectrum
disorders. Recognition of the co-occurrence of concurrent disorders
may provide insight into the therapeutic strategy.
   PMID: 18056691

19. Regression in autism: prevalence and associated factors in the
CHARGE Study

Hansen RL et al.
Ambul Pediatr. 2008 Jan-Feb;8(1):25-31.

OBJECTIVE: The aim of this study was to examine the prevalence of
regressive autism and associated demographic, medical, and
developmental factors by using 2 different definitions of regression
based on the Autism Diagnostic Interview, Revised. METHODS: Subjects
were aged 2 to 5 years, with autism (AU) or autism spectrum disorder
(ASD) confirmed by standardized measures. Children with regression,
defined as a) loss of both language and social skills or b) loss of
either language or social skills, were compared with each other and to
children with AU or ASD with no reported loss of skills on
developmental and adaptive functioning. Parents reported on seizure,
gastrointestinal, and sleep concerns. RESULTS: Fifteen percent
(50/333) of the combined AU-ASD group lost both language and social
skills; 41% (138/333) lost either language or social skills. No
differences were found between the 2 samples of children with
regression. Few developmental, demographic, or medical differences
were found between the combined regression group and children without
loss of skills, in both the larger AU-ASD sample and the more
homogeneous AU-only sample. Children with regression had significantly
lower communication scores than children without regression.
CONCLUSIONS: The prevalence of regression in a large sample of young
children with AU and ASD varies depending on the definition used;
requiring loss of language significantly underestimates the frequency
of developmental regression. Children with regression performed
significantly less well than those without regression on 2 measures of
communication, but the clinical meaningfulness of these differences is
uncertain because of the small effect sizes.
   PMID: 18191778

20. Frequency of gastrointestinal symptoms in children with autistic
spectrum disorders and association with family history of autoimmune
disease

Valicenti-McDermott M et al.
J Dev Behav Pediatr. 2006 Apr;27(2 Suppl):S128-36.

This is a cross-sectional study that compares lifetime prevalence of
gastrointestinal (GI) symptoms in children with autistic spectrum
disorders (ASDs) and children with typical development and with other
developmental disabilities (DDs) and examines the association of GI
symptoms with a family history of autoimmune disease. A structured
interview was performed in 50 children with ASD and 2 control groups
matched for age, sex, and ethnicity-50 with typical development and 50
with other DDs. Seventy-four percent were boys with a mean age of 7.6
years (SD, +/-3.6). A history of GI symptoms was elicited in 70% of
children with ASD compared with 28% of children with typical
development (p <.001) and 42% of children with DD (p =.03). Abnormal
stool pattern was more common in children with ASD (18%) than controls
(typical development: 4%, p =.039; DD: 2%, p =.021). Food selectivity
was also higher in children with ASD (60%) compared with those with
typical development (22%, p =.001) and DD (36%, p =.023). Family
history of autoimmune disease was reported in 38% of the ASD group and
34% of controls and was not associated with a differential rate of GI
symptoms. In the multivariate analysis, autism (adjusted odds ratio
(OR), 3.8; 95% confidence interval (CI), 1.7-11.2) and food
selectivity (adjusted OR, 4.1; 95% CI, 1.8-9.1) were associated with
GI symptoms. Children with ASD have a higher rate of GI symptoms than
children with either typical development or other DDs. In this study,
there was no association between a family history of autoimmune
disease and GI symptoms in children with ASD.
   PMID: 16685179

21. Early medical history of children with autism spectrum disorders

Niehus R, Lord C.
J Dev Behav Pediatr. 2006 Apr;27(2 Suppl):S120-7.

Previous studies have suggested that children with autism spectrum
disorders (ASD) may have different medical histories than nonspectrum
children in several areas: their reactions to vaccinations, number of
ear infections, chronic gastrointestinal problems, and use of
antibiotics. Furthermore, some studies have found associations between
regressive autism and gastrointestinal (GI) symptoms. The present
study analyzes the medical records from birth to the age of 2 years of
99 children (24 typically developing; 75 with ASD, of whom 29 had
parent-reported regression). Data were coded in the following areas:
frequency and purpose of pediatrician visits, frequency and type of
illnesses and medications, type and chronicity of GI complaints, date
of vaccinations, growth data, and whether the pediatrician noted
behaviors indicative of an ASD before the age of 2 years. Children
with ASD were found to have significantly more ear infections than the
typically developing children as well as to use significantly more
antibiotics. Typically developing children had significantly more
illness-related fevers. There was a nonsignificant trend toward the
ASD group having more chronic gastrointestinal problems. There were no
significant differences between the groups for the age of vaccination
or for number of pediatrician visits. Finally, pediatricians noted
symptoms of onset of possible autism, including language delay, for 44
of the 75 children with ASD and 2 of the 24 typical children. Results
are discussed in terms of needs for future research.
   PMID: 16685178

22. Disruption of cerebral cortex MET signaling in autism spectrum
disorder

Campbell DB et al.
Ann Neurol. 2007 Sep;62(3):243-50.

OBJECTIVE: Multiple genes contribute to autism spectrum disorder (ASD)
susceptibility. One particularly promising candidate is the MET gene,
which encodes a receptor tyrosine kinase that mediates hepatocyte
growth factor (HGF) signaling in brain circuit formation, immune
function, and gastrointestinal repair. The MET promoter variant
rs1858830 allele "C" is strongly associated with ASD and results in
reduced gene transcription. Here we examined expression levels of MET
and members of the MET signaling pathway in postmortem cerebral cortex
from ASD cases and healthy control subjects. METHODS: Protein, total
RNA, and DNA were extracted from postmortem temporal cortex gray
matter samples (BA 41/42, 52, or 22) belonging to eight pairs of ASD
cases and matched control subjects. MET protein expression was
determined by Western blotting; messenger RNA expression of MET and
other related transcripts was assayed by microarray and quantitative
reverse transcriptase polymerase chain reaction. RESULTS: MET protein
levels were significantly decreased in ASD cases compared with control
subjects. This was accompanied in ASD brains by increased messenger
RNA expression for proteins involved in regulating MET signaling
activity. Analyses of coexpression of MET and HGF demonstrated a
positive correlation in control subjects that was disrupted in ASD
cases. INTERPRETATION: Altered expression of MET and related molecules
suggests dysregulation of signaling that may contribute to altered
circuit formation and function in ASD. The complement of genes that
encode proteins involved in MET activation appears to undergo long-
term compensatory changes in expression that may be a hallmark
contribution to the pathophysiology of ASD.
   PMID: 17696172

23. A genetic variant that disrupts MET transcription is associated
with autism

Campbell DB et al.
Proc Natl Acad Sci U S A. 2006 Nov 7;103(45):16834-9. Epub 2006 Oct
19.
http://www.pnas.org/cgi/content/full/103/45/16834

There is strong evidence for a genetic predisposition to autism and an
intense interest in discovering heritable risk factors that disrupt
gene function. Based on neurobiological findings and location within a
chromosome 7q31 autism candidate gene region, we analyzed the gene
encoding the pleiotropic MET receptor tyrosine kinase in a family
based study of autism including 1,231 cases. MET signaling
participates in neocortical and cerebellar growth and maturation,
immune function, and gastrointestinal repair, consistent with reported
medical complications in some children with autism. Here, we show
genetic association (P = 0.0005) of a common C allele in the promoter
region of the MET gene in 204 autism families. The allelic association
at this MET variant was confirmed in a replication sample of 539
autism families (P = 0.001) and in the combined sample (P = 0.000005).
Multiplex families, in which more than one child has autism, exhibited
the strongest allelic association (P = 0.000007). In case-control
analyses, the autism diagnosis relative risk was 2.27 (95% confidence
interval: 1.41-3.65; P = 0.0006) for the CC genotype and 1.67 (95%
confidence interval: 1.11-2.49; P = 0.012) for the CG genotype
compared with the GG genotype. Functional assays showed that the C
allele results in a 2-fold decrease in MET promoter activity and
altered binding of specific transcription factor complexes. These data
implicate reduced MET gene expression in autism susceptibility,
providing evidence of a previously undescribed pathophysiological
basis for this behaviorally and medically complex disorder.
   PMID: 17053076

24. Short report: Autistic gastrointestinal and eating symptoms
treated with secretin: a subtype of autism

Pallanti S et al.
Clin Pract Epidemol Ment Health. 2005 Nov 15;1:24.
http://www.cpementalhealth.com/content/1/1/24

Pervasive Developmental Disorders (PDD) are chronic, lifelong
disorders for which there is as yet no effective cure, and medical
management remains a challenge for clinicians. The current report
describes two patients affected by autistic disorder with associated
gastrointestinal symptoms. They received multiple doses of intravenous
secretin for a six-month period and were assessed with several
specific outcome measures to evaluate drug effect. The administration
of secretin led to some significant and lasting improvement in only
one case. Gastroesophageal reflux may contribute to some of the
behavioural problems and explain the effect of secretin since its
suppressive effect on gastric secretion is well known. It is also true
that autistic children with gastroesophageal reflux and a higher IQ
could constitute a subtype which responds to secretin administration
and that could be labelled as a "gastrointestinal subtype".
   PMID: 16287506

25. Constipation with acquired megarectum in children with autism

Afzal N et al.
Pediatrics. 2003 Oct;112(4):939-42.
http://pediatrics.aappublications.org/cgi/content/full/112/4/939

OBJECTIVE: Recent evidence suggests that autistic children may have
significant gastrointestinal symptoms. Although constipation occurs in
2% to 5% of healthy children, its clinical diagnosis is often
difficult in children with behavioral disorders. We thus aimed to
assess the prevalence of fecal loading in autistic children with
gastrointestinal symptoms and to identify possible predictors of
constipation. METHODS: We studied abdominal radiographs of 103
autistic children (87 boys) who were referred for gastroenterological
assessment, in comparison with 29 control radiographs from children
who were referred to the emergency department, most with abdominal
pain. Radiographs were scored independently, in blinded manner, by 4
pediatric gastroenterologists and a radiologist. The severity of
constipation was determined using a validated index. Details of stool
habit, abdominal pain, dietary history, and laxative use were obtained
from case notes. RESULTS: The incidence of constipation in the control
subjects with abdominal pain was higher than reported for normal
children. Despite this, moderate or severe constipation was more
frequent in the autistic group than in the control subjects (36% vs
10%). Analysis of rectosigmoid loading showed more striking
differences (54.4% of autistic children had moderate/severe loading or
acquired megarectum compared with 24.1% of control subjects).
Multivariate regression analysis showed consumption of milk to be the
strongest predictor of constipation in the autistic group, whereas
stool frequency, gluten consumption, soiling, and abdominal pain were
not predictive of constipation. CONCLUSIONS: Constipation is a
frequent finding in children with gastrointestinal symptoms and
autism, particularly in the rectosigmoid colon, often with acquired
megarectum. The absence of any correlation between the clinical
history and the degree of fecal impaction in autistic children
confirms the importance of an abdominal radiograph in the assessment
of their degree of constipation.
   PMID: 14523189