Gastrointestinal symptoms in children with an autism spectrum disorder and language regression

Peripheral neuronal activation shapes the microbiome and alters gut physiology

The gastrointestinal (GI) tract is innervated by intrinsic neurons of the enteric nervous system (ENS) and extrinsic neurons of the central nervous system and peripheral ganglia. The GI tract also harbors a diverse microbiome, but interactions between the ENS and the microbiome remain poorly understood. Here, we activate choline acetyltransferase (ChAT)-expressing or tyrosine hydroxylase (TH)-expressing gut-associated neurons in mice to determine effects on intestinal microbial communities and their metabolites as well as on host physiology. The resulting multi-omics datasets support broad roles for discrete peripheral neuronal subtypes in shaping microbiome structure, including modulating bile acid profiles and fungal colonization. Physiologically, activation of either ChAT+ or TH+ neurons increases fecal output, while only ChAT+ activation results in increased colonic contractility and diarrhea-like fluid secretion. These findings suggest that specific subsets of peripherally activated neurons differentially regulate the gut microbiome and GI physiology in mice without involvement of signals from the brain.

Characterization of Initial Gastrointestinal Evaluation of Children with Autism Spectrum Disorder: A Descriptive Study

Autism spectrum disorder (ASD) is a multifactorial, pervasive neurodevelopmental disorder affecting 1 in 36 children in the United States. Given the rising prevalence and significant economic and social costs associated with ASD, it is critical that continued efforts be made towards better understanding the underlying etiology as well as management of the condition and its commonly associated comorbidities. It has been estimated that upwards of 70% of children with ASD have a positive history of gastrointestinal (GI) symptoms. In this retrospective, descriptive study, we identified 131 patients with diagnosis of autism spectrum disorder who presented for initial evaluation by pediatric gastroenterology at the Baystate Children's Specialty Center. We collected data from chart review of these patients with a particular focus on reason for referral, components of evaluation as well as results of said evaluation. Of the 131 patients, the most frequent reason for referral included constipation (42.7%), abdominal pain (27.5%), and feeding difficulties (26.7%). After completion of the evaluation, 60.3% of patients were ultimately diagnosed with a functional gastrointestinal condition. Of patients who completed endoscopic evaluation, 40% of patients were found to have grossly abnormal and 40% were found to have pathologically abnormal EGD. The majority of patients were recommended to have diagnostic evaluation; however, a large proportion of them were unable to complete said evaluation. The majority of patients were found to have abnormal testing; however, the majority of patients were additionally diagnosed with a functional gastrointestinal condition.

Eating disorder in children: Impact on quality of life, with a spotlight on autism spectrum disorder

Eating behavior, which includes eating habits and preferences, frequency of eating, and other features related to diet, is a major characteristic not only of a person's nutritional status, but also of health in general. In recent years, the prevalence of eating disorders in children has tended to increase; they also require cross-system approaches in diagnosis by a variety of specialists and correction requires appropriate selection of optimal methods. Maladaptive eating attitudes formed at an early age can contribute to the formation of eating disorders, which can lead to or worsen various neuropsychiatric diseases, digestive diseases, and other related conditions. In children with autism spectrum disorder (ASD), eating disorders often appear earlier than other major symptoms of the condition. However, the clinical manifestations of eating disorders in children with ASD are varied and differ in severity and duration, whereas these disorders in neurotypical children might present as short-lived and may not lead to serious consequences. Nevertheless, cases of progressive eating disorders accompanied by a child presenting as under- or overweight and/or with macronutrient and micronutrient deficiencies cannot be excluded. Given the high prevalence of eating disorders in children, many researchers have highlighted the lack of a valid and universally accepted instruments to assess atypical eating behaviors in this population. Therefore, in this review, we wanted to highlight the problems and causes of eating disorders in children, and also to analyze the existing approaches to the validation of these problems, taking into account the existing behavioral features in children with ASD.

Autism spectrum disorders and the gastrointestinal tract: insights into mechanisms and clinical relevance

Autism spectrum disorders (ASDs) are recognized as central neurodevelopmental disorders diagnosed by impairments in social interactions, communication and repetitive behaviours. The recognition of ASD as a central nervous system (CNS)-mediated neurobehavioural disorder has led most of the research in ASD to be focused on the CNS. However, gastrointestinal function is also likely to be affected owing to the neural mechanistic nature of ASD and the nervous system in the gastrointestinal tract (enteric nervous system). Thus, it is unsurprising that gastrointestinal disorders, particularly constipation, diarrhoea and abdominal pain, are highly comorbid in individuals with ASD. Gastrointestinal problems have also been repeatedly associated with increased severity of the core symptoms diagnostic of ASD and other centrally mediated comorbid conditions, including psychiatric issues, irritability, rigid-compulsive behaviours and aggression. Despite the high prevalence of gastrointestinal dysfunction in ASD and its associated behavioural comorbidities, the specific links between these two conditions have not been clearly delineated, and current data linking ASD to gastrointestinal dysfunction have not been extensively reviewed. This Review outlines the established and emerging clinical and preclinical evidence that emphasizes the gut as a novel mechanistic and potential therapeutic target for individuals with ASD.

Developmental regression in children: Current and future directions

Developmental regression describes when a child loses previously established skills, such as the ability to speak words and is most recognised in neurodevelopmental conditions including Autism; Developmental Epileptic Encephalopathies, such as Landau Kleffner syndrome, and genetic conditions such as Rett syndrome and Phelan McDermid syndrome. Although studies have reported developmental regression for over 100 years, there remain significant knowledge gaps within and between conditions that feature developmental regression. The certainty of evidence from earlier work has been limited by condition-specific studies, retrospective methodology, and inconsistency in the definitions and measures used for classification. Given prior limitations in the field, there is a paucity of knowledge about neurocognitive mechanisms, trajectories and outcomes for children with developmental regression, and their families. Here we provide a comprehensive overview, synthesise key definitions, clinical measures, and aetiological clues associated with developmental regression and discuss impacts on caregiver physical and mental health to clarify challenges and highlight future directions in the field.

Questionnaire-based analysis of autism spectrum disorders and gastrointestinal symptoms in children and adolescents: a systematic review and meta-analysis

Background

Gastrointestinal (GI) symptoms are frequently experienced by children with autism spectrum disorder (ASD), and these symptoms cause difficulties for these children and their families. However, studies of GI symptom prevalence differ significantly. This meta-analysis aimed to analyze the prevalence of GI symptoms in children with ASD.

Methods and findings

PubMed, Scopus, Web of Science, EMBASE were electronically searched to collect all literature on gastrointestinal symptoms of children with ASD collected through questionnaires or scales from January 2012 to May 2021. Four researchers independently scanned the literature and extracted information on general characteristics. First author name, year of publication, geographical location, type of study, sample sizes of ASD and control (if any) children, sex and average age, number of GI cases, number of GI symptoms, GI assessment tools (gastrointestinal symptoms scale), autism diagnosis methods, and other necessary data were collected and analyzed using Stata V16. The questionnaires included the Rome, 6-GSI, GIQ, GSRS, GSIQ, ADI-R, PedsQL-GI, parent-report, GI-related, and self-administered questionnaires. Compared with typically developing (TD) children, the odds ratio for In children with ASD with at least one GI symptom was 3.64, and the total prevalence was 55%. The cumulative prevalence rates of various symptoms were summarized, showing that 37% of children with ASD had constipation, 21% had abdominal pain, 19% had diarrhea, 8% had vomiting, and 23% had abdominal distension.

Conclusions

The results of this meta-analysis on GI symptoms in ASD show that patients with ASD are more likely to develop symptoms than TD children. The prevalence of GI symptoms in In children with ASD was 55%.

Systematic Review Registration

www.crd.york.ac.uk/PROSPERO, identifier, #CRD42017080579.

Altered gut microbiota correlates with behavioral problems but not gastrointestinal symptoms in individuals with autism

BACKGROUND

Despite inconsistent results across studies, emerging evidence suggests that the microbial micro-environment may be associated with autism spectrum disorder (ASD). Geographical and cultural factors highly impact microbial profiles, and there is a shortage of data from East Asian populations. This study aimed to comprehensively characterize microbial profiles in an East Asian sample and explore whether gut microbiota contributes to clinical symptoms, emotional/behavioral problems, and GI symptoms in ASD.

METHODS

We assessed 82 boys and young men with ASD and 31 typically developing controls (TDC), aged 6-25 years. We analyzed the stool sample of all participants with 16S V3-V4 rRNA sequencing and correlated its profile with GI symptoms, autistic symptoms, and emotional/behavioral problems.

RESULTS

Autistic individuals, compared to TDC, had worse GI symptoms. There were no group differences in alpha diversity of species richness estimates (Shannon-wiener and Simpson diversity indices). Participants with ASD had an increased relative abundance of Fusobacterium, Ruminococcus torques group (at the genus level), and Bacteroides plebeius DSM 17135 (at the species level), while a decreased relative abundance of Ruminococcaceae UCG 013, Ervsipelotrichaceae UCG 003, Parasutterella, Clostridium sensu stricto 1, Turicibacter (at the genus level), and Clostridium spiroforme DSM 1552 and Intestinimonas butyriciproducens (at the species level). Altered taxonomic diversity in ASD significantly correlated with autistic symptoms, thought problems, delinquent behaviors, self dysregulation, and somatic complaints. We did not find an association between gut symptoms and gut microbial dysbiosis.

CONCLUSIONS

Our findings suggest that altered microbiota are associated with behavioral phenotypes but not GI symptoms in ASD. The function of the identified microbial profiles mainly involves the immune pathway, supporting the hypothesis of a complex relationship between altered microbiome, immune dysregulation, and ASD that may advance the discovery of molecular biomarkers for ASD.

Integrative Functional Genomic Analysis in Multiplex Autism Families from Kazakhstan

The study of extended pedigrees containing autism spectrum disorder- (ASD-) related broader autism phenotypes (BAP) offers a promising approach to the search for ASD candidate variants. Here, a total of 650,000 genetic markers were tested in four Kazakhstani multiplex families with ASD and BAP to obtain data on de novo mutations (DNMs), common, and rare inherited variants that may contribute to the genetic risk for developing autistic traits. The variants were analyzed in the context of gene networks and pathways. Several previously well-described enriched pathways were identified, including ion channel activity, regulation of synaptic function, and membrane depolarization. Perhaps these pathways are crucial not only for the development of ASD but also for ВАР. The results also point to several additional biological pathways (circadian entrainment, NCAM and BTN family interactions, and interaction between L1 and Ankyrins) and hub genes (CFTR, NOD2, PPP2R2B, and TTR). The obtained results suggest that further exploration of PPI networks combining ASD and BAP risk genes can be used to identify novel or overlooked ASD molecular mechanisms.

Managing constipation in children with ASD - A challenge worth tackling

Autism Spectrum disorder (ASD) is well known to be associated with significantly high rates of gastrointestinal problems, constipation being common among them, imposing a significant burden on child and the family. On account of multiple underlying factors, both diagnosis and subsequent management of constipation in children with ASD are much more challenging as compared to managing constipation in 'neurotypical' children. Associated higher rate of presentation to the hospital emergency and subsequent hospital admission rates add to the burden. Hence, there is a need for recognizing constipation as a problem in children with ASD. This review summarizes optimization of its management by adopting a multidisciplinary holistic approach to achieve good outcomes and enhance the quality of life for the child and the family.

Gastrointestinal Symptoms in Autism Spectrum Disorder: A Systematic Review

This systematic review aims to offer an updated understanding of the relationship between gastrointestinal symptoms (GIS) and autism spectrum disorder (ASD) in children and adolescents. The databases PsycINFO, Medline, Cinahl, and ERIC were searched using keywords, and relevant literature was hand-searched. Papers (n = 3319) were systematically screened and deemed eligible if they were empirical studies published in English since 2014 and measured the GIS of individuals with ASD who were under 18 years old. Thirty studies were included in the final review. The study findings were synthesized under eight themes, including the prevalence and nature of GIS and their relationship with developmental regression, language and communication, ASD severity, challenging behavior, comorbid psychopathology, sleep problems, and sensory issues. The review found that GIS were common and that there was contradictory evidence concerning their relationship with co-occurring conditions. It also identified evidence of some causal relationships that support the existence of the gut–immune–brain pathways. Future research needs to use large prospective designs and objective and standardized GIS measurements to provide a nuanced understanding of GIS in the context of ASD.

Age of Autism Spectrum Disorder Diagnosis and Comorbidity in Children and Adolescents with Autism Spectrum Disorder

AIM

Research is required to study the relationship between age of autism spectrum disorder (ASD) diagnosis and the presence of comorbidities.

METHOD

The Gastrointestinal Symptom Inventory, Autism Spectrum Disorder-Comorbid for Children, Behavior Problem Inventory-Short Form and Social Communication Questionnaire were completed by parents of 129 children and adolescents with a diagnosis of ASD.

RESULTS

Results revealed significant relationships between the age of ASD diagnosis, the presence of comorbidities and intellectual disability. Significant correlations were found between the age of ASD diagnosis and self-injurious and stereotyped behavior. Comorbid psychopathology significantly predicted the presence of GI symptoms. In addition, the relationship between comorbid psychopathology and challenging behavior in this study was reported as bi-directional as both comorbidities predicted one another in the sample.

CONCLUSION

Future research needs to consider the role of comorbidities in relation to ASD diagnosis.

Gastrointestinal involvement of autism spectrum disorder: focus on gut microbiota

INTRODUCTION

Autism spectrum disorder (ASD) is a neurodevelopmental disorder typical of early age, characterized by impaired communication, social interaction, and repetitive behaviors. ASD patients frequently suffer from gastrointestinal (GI) symptoms. Neuro-psychological functions, intestinal homeostasis, and functional GI disturbances are modulated by the gut microbiota through the so-called 'microbiota-gut-brain axis'.

AREAS COVERED

Literature regarding GI symptoms among the ASD community as well as the involvement and modulation of the gut microbiota in GI disturbances of ASD patients was searched. Constipation, diarrhea, reflux, abdominal bloating, pain, and discomfort are reported with variable prevalence. ASD is characterized by a reduction of Bacteroidetes/Firmicutes, of the abundance of Bacteroidetes and other imbalances. ASD patients with GI symptoms present microbial changes with plausible relation with deficiency of digestive enzymes, carbohydrate malabsorption, selective eating, bacterial toxins, serotonin metabolism, and inflammation. The strategies to mitigate the GI distress through the gut microbiota modulation comprise antimicrobials, probiotics, prebiotics, fecal microbiota transplantation, and dietary intervention.

EXPERT OPINION

The modulation of the gut microbiota in ASD individuals with GI disturbances seems a promising target for the future medicine. A standardization of the research strategies for large-scale studies together with a focus on poorly explored fields is necessary to strengthen this hypothesis.

Attention deficit hyperactivity disorder (ADHD) symptoms, comorbid psychopathology, behaviour problems and gastrointestinal symptoms in children and adolescents with autism spectrum disorder

OBJECTIVES

The study aims to investigate attention deficit hyperactivity disorder (ADHD) symptoms, gastrointestinal (GI) symptoms, comorbid psychopathology and behaviour problems in children and adolescents with autism spectrum disorder (ASD).

METHODS

Parents of 147 children and adolescents with ASD aged 6-18 years completed the Conners 3 Parent-Short Form, Gastrointestinal Symptom Inventory, Behavior Problems Inventory-Short Form and Autism Spectrum Disorder-Comorbid for Children.

RESULTS

Fifty-six per cent of children and adolescents had a comorbid diagnosis of ADHD, yet over 70% presented with clinically significant ADHD symptoms. Forty per cent of participants received a diagnosis of ADHD before ASD and 25.6% received a diagnosis of ASD first. Relationships were found between ADHD symptoms and comorbid psychopathology, GI symptoms, and behaviour problems.

CONCLUSIONS

The outcomes suggest that ADHD is being underestimated as a comorbid disorder of ASD. This may have implications on treatment and interventions for children and adolescents who have a diagnosis of both ASD and ADHD.

Gluten and Autism Spectrum Disorder

An expanding body of literature is examining connections between Autism Spectrum Disorder (ASD) and dietary interventions. While a number of specialist diets have been suggested as beneficial in ASD, gluten has received particularly close attention as a potentially exacerbating factor. Reports exist suggesting a beneficial effect of the gluten-free diet (GFD) in ameliorating behavioural and intellectual problems associated with ASD, while epidemiological research has also shown a comorbidity between ASD and coeliac disease. However, both caregivers and clinicians have expressed an uncertainty of the value of people with ASD going gluten-free, and as the GFD otherwise receives considerable public attention a discussion which focuses specifically on the interaction between ASD and gluten is warranted. In this review we discuss the historical context of ASD and gluten-related studies, and expand this to include an overview of epidemiological links, hypotheses of shared pathological mechanisms, and ultimately the evidence around the use and adoption of the GFD in people with ASD.

Gastrointestinal Symptoms in 2- to 5-Year-Old Children in the Study to Explore Early Development

Gastrointestinal symptoms (GIS) are commonly reported in children with autism spectrum disorder (ASD). This multi-site study evaluated the prevalence of GIS in preschool-aged children with ASD/(n = 672), with other developmental delays (DD)/(n = 938), and children in the general population (POP)/(n = 851). After adjusting for covariates, children in the ASD group were over 3 times more likely to have parent-reported GIS than the POP group, and almost 2 times more likely than the DD group. Children with GIS from all groups had more behavioral and sleep problems. Within the ASD group, children with developmental regression had more GIS than those without; however, there were no differences in autism severity scores between children with and without GIS. These findings have implications for clinical management.

Autism Spectrum Disorder and Medical Cannabis: Review and Clinical Experience

Autism spectrum disorder (ASD) is a multifactorial, pervasive neurodevelopmental disorder defined by the core symptoms of significant impairment in social interaction and communication as well as restricted, repetitive patterns of behavior. In addition to these core behaviors, persons with ASD frequently have associated noncore behavioral disturbance (ie, self-injury, aggression), as well as several medical comorbidities. Currently, no effective treatment exists for the core symptoms of ASD. This review reports the available preclinical and clinical data regarding the use of cannabis and cannabidiol in the treatment of core symptoms, noncore symptoms and comorbidities associated with ASD. Additionally, we describe our clinical experience working with children and young adults with ASD who have used cannabis or cannabidiol. At present, preclinical and clinical data suggest a potential for therapeutic benefit among some persons with ASD and that it is overall well tolerated. Further research is required to better identify patients who may benefit from treatment without adverse effects.

Developmental-behavioral profiles in children with autism spectrum disorder and co-occurring gastrointestinal symptoms

Gastrointestinal (GI) symptoms are frequently reported in children with autism spectrum disorder (ASD). We evaluated the frequency and severity of GI symptoms in preschool-aged children with ASD compared to participants with typical development (TD). Our goal was to ascertain whether GI symptoms are associated with differences in sex or developmental and behavioral measures. Participants were between 2 and 3.5 years of age and included 255 children with ASD (184 males/71 females) and 129 age-matched TD controls (75 males/54 females). A parent interview was used to assess GI symptoms (abdominal pain, gaseousness/bloating, diarrhea, constipation, pain on stooling, vomiting, difficulty swallowing, blood in stool or in vomit). Children with GI symptoms in each diagnostic group were compared to children without GI symptoms on measures of developmental, behavioral, and adaptive functioning. GI symptoms were reported more frequently in children with ASD compared to the TD group (47.8% vs. 17.8%, respectively). Children with ASD were also more likely to experience multiple GI symptoms (30.6% vs. 5.4%). GI symptoms were equally common in males and females across both diagnostic groups. There were no statistically significant differences in developmental or adaptive measures based on presence of GI symptoms in either ASD or TD children. Co-occurring GI symptoms were, however, associated with increased self-injurious behaviors, restricted stereotyped behaviors, aggressive behaviors, sleep problems and attention problems in both ASD and TD children. In children with ASD, a higher number of GI symptoms was associated with an increase in self-injurious behaviors, somatic complaints, reduced sleep duration, and increased parasomnias. LAY SUMMARY: ASD is characterized by challenges in social communication and repetitive behaviors. But, people with autism have many other difficulties including gastrointestinal problems. Children with ASD were three times more likely to experience GI symptoms than typically developing peers. Increased GI symptoms are associated with increased problem behaviors such as sleep problems, self-injury, and body aches. Since GI symptoms are often treatable, it is important to recognize them as soon as possible. Both clinicians and parents should become more aware of the high occurrence of GI problems in autistic people. Autism Res 2020, 13: 1778-1789. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

A Descriptive Review on the Prevalence of Gastrointestinal Disturbances and Their Multiple Associations in Autism Spectrum Disorder

Background and Objectives: Gastrointestinal disturbances have been frequently, but not unanimously, reported in autism spectrum disorder (ASD) individuals. Thus, digestive symptoms, such as constipation, diarrhea, abdominal bloating, and pain have been reported to correlate to the various maladaptive behaviors in ASD children, such as irritability, social withdrawal, stereotypy, hyperactivity, and even language regression. In this context, the present study provides an overview on the prevalence of the gastrointestinal (GI) disorders in ASD and the correlation between these and ASD symptoms and comorbidities and subsequently discusses the metabolic and microbiome factors underlying the effects of GI disorders in ASD. Materials and Methods: For our analysis of GI symptoms in children with ASD, we have searched peer-reviewed journals from 2005 to 2017 in PubMed databases that addressed the specificity of GI symptoms in ASD and included correlations of GI and ASD symptoms. The criteria for inclusion were clear quantitative mentioning of GI modifications, GI symptoms correlation with specific ASD symptoms or comorbidities, an appropriate methodology for defining ASD, and larger size samples. For this topic, only studies on human patients and original research were considered. A subsequent search in PubMed databases in journals from 2000 to 2017 we analyzed 13 articles on the mechanisms underlying the impact of GI dysfunctions in ASD, including gut microbial dysbiosis, immune reactivity, genetics, and altered neurotransmitters on the gut-brain axis. Results: In the 18 original research studies that we selected out of an initial 327 studies, despite the different methodology, a predominant 83% highlighted the increased prevalence of GI symptoms in ASD patients. Constipation was most frequently cited, appearing in 12 of the studies (80%), followed by diarrhea reports in eight studies (53%). The association between cognitive and behavioral deficits and GI disorders was suggested in certain groups of ASD individuals. Conclusion: The evidence presented so far by numerous studies seems to indicate that GI dysfunctions are of particular relevance in ASD, underlined by various abnormalities along the nervous connections between the central nervous system and the gut, such as impaired parasympathetic activity and increased endocrine stress response. Sufficiently large size samples and standardized methodology are required for future studies to clarify the complex interactions between GI disturbances and ASD symptoms.

Vocal and motor behaviors as a possible expression of gastrointestinal problems in preschoolers with Autism Spectrum Disorder

Background

Gastrointestinal (GI) problems are one of the most frequent comorbidities in Autism Spectrum Disorder (ASD) but can be under-recognized due to the concomitant communication difficulties of this population. Accordingly, some associated behaviors (AB) such as verbal and motor behaviors (VB and MB, respectively) have been identified as a possible expression of an underlying GI problem and evaluated through an ad hoc questionnaire (the Associated Behaviors Questionnaire -ABQ-). The aims of this study were to investigate the presence and the type of AB in an Italian sample of ASD preschoolers, and to determine their correlations with GI problems.

Methods

We included 85 ASD preschoolers (mean age 4.14 years; SD 1.08) splitted into two groups (GI and No-GI) through the GI Severity Index instrument. AB were evaluated through the ABQ that includes VB, MB and Changes in overall state (C) clusters. Specific tools were administered to evaluate the ASD core ad associated symptoms, as well as the intellective and adaptive functioning.

Results

The GI group (N = 30) showed significantly higher scores in all the three ABQ areas (VB, MB and C) than the No-GI group (N = 55), with a positive correlation between GI symptoms and some specific AB as well as ABQ Total score. By dividing the whole sample in verbal and non-verbal individuals, both specific and shared AB emerged in the two groups.

Conclusions

Our results alert clinicians to consider behavioral manifestations as a possible expression of GI problems in ASD subjects. Therefore, the evaluation of AB may be useful to identify the presence of GI problems in the ASD populations, and especially in non-verbal ASD children.

Social Differences Between Monolingual English and Bilingual English-Spanish Children With Autism Spectrum Disorders

OBJECTIVE

Bilingualism is increasingly prevalent; however, research in bilingual children with autism is sparse. The purpose of this study was to compare social skills and autistic features in monolingual English and bilingual English-Spanish children with autism spectrum disorder.

METHODS

We conducted a review of the multidisciplinary evaluations done in all children aged one to six years diagnosed with autism spectrum disorder in an inner city, university-affiliated clinic from 2003 to 2013. Collected information included demographics, developmental testing, and autistic characteristics.

RESULTS

We identified 462 children; 165 were bilingual English-Spanish and 297 were monolingual English. Parents of bilingual children reported stereotyped or repetitive use of language more often (66% vs 48% P = 0.002) than monolinguals. Significant differences were not found in social interaction, use of nonverbal behaviors, peer relationships, sharing or social or emotional reciprocity, mannerisms, or autism severity.

CONCLUSIONS

Bilingualism does not seem to confer an extra vulnerability on children with autism spectrum disorder; however, differences in qualitative use of language were observed.

HLA-DQ Genotyping, Duodenal Histology, and Response to Exclusion Diet in Autistic Children With Gastrointestinal Symptoms

OBJECTIVES

A correlation between autism spectrum disorders (ASDs) and gastrointestinal (GI) problems, and a possible link between gluten consumption and ASD have been increasingly reported. Gluten/casein-free diet (GCFD) is often undertaken, with conflicting results. This study aimed at evaluating the distribution of human leukocyte antigen (HLA)-DQ2/DQ8 typing among patients with ASD with GI symptoms, together with its correlation with duodenal histology and response to GCFD.

METHODS

Between 2002 and 2015 all patients with ASD with GI symptoms referred to our outpatient clinic, displaying clinical, laboratory, or ultrasound findings suggestive of organic disease, underwent endoscopy, celiac disease (CD) serum antibodies testing and HLA-DQ2/DQ8 genotyping. Patients were prescribed a 6-month GCFD, and then clinically reassessed.

RESULTS

Among 151 enrolled patients, 134 (89%) were negative for CD-specific antibodies; 72 (48%) were positive for HLA-DQ2/DQ8; and 56 (37%) showed duodenal microscopic inflammation. Clinical improvement was observed in non-CD patients irrespective of the rigorous or partial adherence to the diet, being the difference nonstatistically significant. Response to diet was related to the presence of histological duodenal alterations at baseline (odds ratio 11.323, 95% confidence interval 1.386-92.549 for Marsh 2 pattern), but not to HLA-DQ2/DQ8 positivity (odds ratio 1.120, 95% confidence interval 0.462-2.716).

CONCLUSIONS

Our data suggest that children with ASD with GI symptoms have a high prevalence of duodenal intraepithelial lymphocytic infiltration, which seems to be linked to a mechanism other than autoimmune response to gluten consumption. Alteration of duodenal histology, but not the HLA-DQ2/DQ8 status, was associated with clinical response to the diet.

Association of Autism Spectrum Disorders and Inflammatory Bowel Disease

Autism spectrum disorders (ASD) and inflammatory bowel disease (IBD) both have multifactorial pathogenesis with an increasing number of studies demonstrating gut-brain associations. We aim to examine the association between ASD and IBD using strict classification criteria for IBD. We conducted a retrospective case-cohort study using records from the Military Health System database with IBD defined as having one encounter with an ICD-9-CM diagnostic code for IBD and at least one outpatient prescription dispensed for a medication to treat IBD. Children with ASD were more likely to meet criteria for Crohn's disease (CD) and Ulcerative colitis (UC) compared to controls. This higher prevalence of CD and UC in children with ASD compared to controls confirms the association of ASD with IBD.

Genetic predictors of celiac disease, lactose intolerance, and vitamin D function and presence of peptide morphins in urine of children with neurodevelopmental disorders

Gastrointestinal disturbances, nutritional deficiencies, and food intolerances are frequently observed in children with neurodevelopmental disorders (NDD). To reveal possible association of celiac disease risk variants (HLA-DQ), lactose intolerance associated variant (LCT-13910C>T) as well as variant associated with vitamin D function (VDR FokI) with NDD, polymerase chain reaction-based methodology was used. Additionally, intestinal peptide permeability was estimated in NDD patients and healthy children by measuring the level of peptides in urine using high-performance liquid chromatography. Levels of opioid peptides, casomorphin 8, and gluten exorphin C were significantly elevated in urine samples of NDD patients (P = 0.004 and P = 0.005, respectively), but no association of genetic risk variants for celiac disease and lactose intolerance with NDD was found. Our results indicate that increased intestinal peptide permeability observed in analyzed NDD patients is not associated with genetic predictors of celiac disease or lactose intolerance. We have also found that FF genotype of VDR FokI and lower serum levels of vitamin D (25-OH) showed association with childhood autism (CHA), a subgroup of NDD. We hypothesize that vitamin D might be important for the development of CHA.

Evolution in the Understanding of Autism Spectrum Disorder: Historical Perspective

The study of the evolution in the diagnosis and treatment of autism is a lesson in the dangers of medical beliefs or doctrines that are not grounded in medical science. The early descriptions of autism suggested that it was the result of childhood psychoses or psychodynamic disturbances of parent-child relationships. This flawed conceptualization of autism spectrum disorders (ASD) gave way to advances in medical science, which have established ASD as a neurobiological disorder of early brain development. There are many genetic, epigenetic, metabolic, hormonal, immunological, neuroanatomical and neurophysiological etiologies of ASD, as well as an array of gastrointestinal and other systemic co-morbid disorders. Thus, ASD are a biologically heterogeneous population with extensive neurodiversity. Early identification and understanding of ASD is crucial; interventions at younger ages are associated with improved outcomes. The advent of understanding the biological sub-phenotypes of ASD, along with targeted medical therapies, coupled with a multimodal therapeutic approach that encompasses behavioral, educational, social, speech, occupational, creative arts, and other forms of therapies has created a new and exciting era for individuals with ASD and their families: "personalized" and "precision" medical care based upon underlying biological sub-phenotypes and clinical profiles. For many individuals and their families dealing with the scourge of autism, their long and frustrating diagnostic journey is beginning to come to an end, with a hope for improved outcomes and quality of life.

Blood-brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders

Background

Autism spectrum disorders (ASD) are complex conditions whose pathogenesis may be attributed to gene–environment interactions. There are no definitive mechanisms explaining how environmental triggers can lead to ASD although the involvement of inflammation and immunity has been suggested. Inappropriate antigen trafficking through an impaired intestinal barrier, followed by passage of these antigens or immune-activated complexes through a permissive blood–brain barrier (BBB), can be part of the chain of events leading to these disorders. Our goal was to investigate whether an altered BBB and gut permeability is part of the pathophysiology of ASD.

Methods

Postmortem cerebral cortex and cerebellum tissues from ASD, schizophrenia (SCZ), and healthy subjects (HC) and duodenal biopsies from ASD and HC were analyzed for gene and protein expression profiles. Tight junctions and other key molecules associated with the neurovascular unit integrity and function and neuroinflammation were investigated.

Results

Claudin (CLDN)-5 and -12 were increased in the ASD cortex and cerebellum. CLDN-3, tricellulin, and MMP-9 were higher in the ASD cortex. IL-8, tPA, and IBA-1 were downregulated in SCZ cortex; IL-1b was increased in the SCZ cerebellum. Differences between SCZ and ASD were observed for most of the genes analyzed in both brain areas. CLDN-5 protein was increased in ASD cortex and cerebellum, while CLDN-12 appeared reduced in both ASD and SCZ cortexes. In the intestine, 75% of the ASD samples analyzed had reduced expression of barrier-forming TJ components (CLDN-1, OCLN, TRIC), whereas 66% had increased pore-forming CLDNs (CLDN-2, -10, -15) compared to controls.

Conclusions

In the ASD brain, there is an altered expression of genes associated with BBB integrity coupled with increased neuroinflammation and possibly impaired gut barrier integrity. While these findings seem to be specific for ASD, the possibility of more distinct SCZ subgroups should be explored with additional studies.

Psychophysiological Associations with Gastrointestinal Symptomatology in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is often accompanied by gastrointestinal disturbances, which also may impact behavior. Alterations in autonomic nervous system functioning are also frequently observed in ASD. The relationship between these findings in ASD is not known. We examined the relationship between gastrointestinal symptomatology, examining upper and lower gastrointestinal tract symptomatology separately, and autonomic nervous system functioning, as assessed by heart rate variability and skin conductance level, in a sample of 120 individuals with ASD. Relationships with co-occurring medical and psychiatric symptoms were also examined. While the number of participants with significant upper gastrointestinal tract problems was small in this sample, 42.5% of participants met criteria for functional constipation, a disorder of the lower gastrointestinal tract. Heart rate variability, a measure of parasympathetic modulation of cardiac activity, was found to be positively associated with lower gastrointestinal tract symptomatology at baseline. This relationship was particularly strong for participants with co-occurring diagnoses of anxiety disorder and for those with a history of regressive ASD or loss of previously acquired skills. These findings suggest that autonomic function and gastrointestinal problems are intertwined in children with ASD; although it is not possible to assess causality in this data set. Future work should examine the impact of treatment of gastrointestinal problems on autonomic function and anxiety, as well as the impact of anxiety treatment on gastrointestinal problems. Clinicians should be aware that gastrointestinal problems, anxiety, and autonomic dysfunction may cluster in children with ASD and should be addressed in a multidisciplinary treatment plan. Autism Res 2017, 10: 276-288. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Breast Milk Protects Against Gastrointestinal Symptoms in Infants at High Risk for Autism During Early Development

OBJECTIVES

Parents of children with autism spectrum disorders (ASDs) often report gastrointestinal (GI) dysfunction in their children. The objectives of the present study were to determine whether infants at high risk for developing ASD (ie, siblings of children diagnosed as having ASD) show greater prevalence of GI problems and whether this prevalence is associated with diet and age at weaning from breast milk.

METHODS

Using questionnaires, diet history and GI problems were tracked prospectively and retrospectively in 57 high-risk infants and for comparison in 114 low-risk infants (infants from families without ASD history).

RESULTS

In low-risk infants, prevalence of GI symptoms, in aggregate, did not vary with diet or age of weaning. By contrast, high-risk infants with GI symptoms were weaned earlier than those without symptoms (P < 0.04), and high-risk infants showed greater prevalence of GI symptoms, in aggregate, on a no breast milk diet than on an exclusive breast milk diet (P < 0.017). Constipation, in particular, was more prevalent in high-risk infants compared with low-risk infants (P = 0.01), especially on a no breast milk diet (P = 0.002). High-risk infants who completed weaning earlier than 6 months showed greater prevalence of constipation (P = 0.001) and abdominal distress (P = 0.004) than those fully weaned after 6 months.

CONCLUSIONS

The greater prevalence of GI symptoms in high-risk infants suggests that GI dysfunction during early infant development may be a part of the ASD endophenotype. Late weaning and exclusive breast milk were associated with protection against GI symptoms in high-risk infants.

Prevalence of Inflammatory Bowel Disease Among Patients with Autism Spectrum Disorders

BACKGROUND

The objective of this study was to measure the prevalence of inflammatory bowel disease (IBD) among patients with autism spectrum disorders (ASD), which has not been well described previously.

METHODS

The rates of IBD among patients with and without ASD were measured in 4 study populations with distinct modes of ascertainment: a health care benefits company, 2 pediatric tertiary care centers, and a national ASD repository. The rates of IBD (established through International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes) were compared with respective controls and combined using a Stouffer meta-analysis. Clinical charts were also reviewed for IBD among patients with ICD-9-CM codes for both IBD and ASD at one of the pediatric tertiary care centers. This expert-verified rate was compared with the rate in the repository study population (where IBD diagnoses were established by expert review) and in nationally reported rates for pediatric IBD.

RESULTS

In all of case-control study populations, the rates of IBD-related ICD-9-CM codes for patients with ASD were significantly higher than that of their respective controls (Stouffer meta-analysis, P < 0.001). Expert-verified rates of IBD among patients with ASD were 7 of 2728 patients in one study population and 16 of 7201 in a second study population. The age-adjusted prevalence of IBD among patients with ASD was higher than their respective controls and nationally reported rates of pediatric IBD.

CONCLUSIONS

Across each population with different kinds of ascertainment, there was a consistent and statistically significant increased prevalance of IBD in patients with ASD than their respective controls and nationally reported rates for pediatric IBD.

Serotonin mediated immunoregulation and neural functions: Complicity in the aetiology of autism spectrum disorders

Serotonergic system has long been implicated in the aetiology of autism spectrum disorders (ASD), since platelet hyperserotonemia is consistently observed in a subset of autistic patients, who respond well to selective serotonin reuptake inhibitors. Apart from being a neurotransmitter, serotonin functions as a neurotrophic factor directing brain development and as an immunoregulator modulating immune responses. Serotonin transporter (SERT) regulates serotonin level in lymphoid tissues to ensure its proper functioning in innate and adaptive responses. Immunological molecules such as cytokines in turn regulate the transcription and activity of SERT. Dysregulation of serotonergic system could trigger signalling cascades that affect normal neural-immune interactions culminating in neurodevelopmental and neural connectivity defects precipitating behavioural abnormalities, or the disease phenotypes. Therefore, we suggest that a better understanding of the cross talk between serotonergic genes, immune systems and serotonergic neurotransmission will open wider avenues to develop pharmacological leads for addressing the core ASD behavioural deficits.

Clinical differences in children with autism spectrum disorder with and without food selectivity

Several studies have described the atypical eating behaviors frequently occurring in children with Autism Spectrum Disorder (ASD), and food selectivity is the most frequent of these problems. The everyday management of mealtime behaviors among children with ASD can have a negative impact on family routines and become a significant stressor for families. However, much remains unknown about why food selectivity is so prevalent among individuals with ASD. The objective of this study was to investigate clinical and behavioral features in individuals with ASD with the aim of identifying distinctive clinical profiles in children with and without food selectivity. A total of 158 children with ASD were enrolled in this study: 79 participants with food selectivity (FS) were age and sex matched with 79 participants without food selectivity (No FS). All participants and their parents completed a battery of psychological tests for a comprehensive evaluation of ASD symptoms, cognitive abilities, adaptive skills, behavioral problems and parental stress level. No statistically significant difference on gastrointestinal symptoms and growth adequacy was found between the FS group and the No FS group. Overall, the FS group showed significantly higher rates of ASD symptoms as compared to the No FS group in the questionnaires completed by parents. Furthermore, parents of the FS group reported significantly higher levels of parental stress and a larger degree of their children's behavioral problems as compared to the No FS group. Finally, there were no differences between the FS and the No FS group on any adaptive skill domain. Our findings suggest that the identification of distinctive clinical and behavioral patterns in children with ASD and food selectivity is a crucial issue for parents and therapists in the daily management.

Overview of biomarkers for diagnosis and monitoring of celiac disease

Among the adverse reactions caused by wheat, celiac disease (CD) is the longest studied and best-known pathology. The more recently defined non-celiac gluten sensitivity (NCGS) presents with symptoms which are often indistinguishable from CD. Diagnosis of CD is based on serologic, molecular, and bioptic testing. The IgA anti-transglutaminase (tTG) test is considered highly important, as it shows high sensitivity and specificity and its levels correlate to the degree of intestinal damage. Small bowel biopsy can be avoided in symptomatic patients with IgA anti-tTG levels above 10× the manufacturer's cut-off. Recently, tests of anti-deamidated peptides of gliadin (DGP) have replaced classic anti-native gliadin (AGA) tests. DGP assays have a considerably higher diagnostic accuracy than AGA assays, especially in the IgG class, and can replace anti-tTG tests in patients with selective IgA deficiency. The combination of IgG anti-DGP plus IgA anti-tTG assays show greater sensitivity than a single test, with very high specificity. EMA tests have great diagnostic accuracy but are not recommended by all the latest guidelines because they are observer dependent. Biopsy must still be considered the gold standard for CD diagnosis. HLA-DQ genotyping can be used to screen asymptomatic children and in cases of histology/serology disagreement. About half of NCGS patients are DQ2 positive and have IgG AGA. To diagnose NCGS, first CD and wheat allergy must be excluded; then the wheat dependence of symptoms must be verified by a gluten-free diet and subsequent gluten challenge.

Parent-reported gastro-intestinal symptoms in children with autism spectrum disorders

The objective of this study is to investigate whether parentally-reported gastro-intestinal (GI) symptoms are increased in a population-derived sample of children with autism spectrum disorders (ASD) compared to controls. Participants included 132 children with ASD and 81 with special educational needs (SEN) but no ASD, aged 10-14 years plus 82 typically developing (TD) children. Data were collected on GI symptoms, diet, cognitive abilities, and developmental histories. Nearly half (weighted rate 46.5 %) of children with ASD had at least one individual lifetime GI symptom compared with 21.8 % of TD children and 29.2 % of those with SEN. Children with ASD had more past and current GI symptoms than TD or SEN groups although fewer current symptoms were reported in all groups compared with the past. The ASD group had significantly increased past vomiting and diarrhoea compared with the TD group and more abdominal pain than the SEN group. The ASD group had more current constipation (when defined as bowel movement less than three times per week) and soiling than either the TD or SEN groups. No association was found between GI symptoms and intellectual ability, ASD severity, ASD regression or limited or faddy diet. Parents report more GI symptoms in children with ASD than children with either SEN or TD children but the frequency of reported symptoms is greater in the past than currently in all groups.

Rigid-compulsive behaviors are associated with mixed bowel symptoms in autism spectrum disorder

Based on clinical experience, we hypothesized that rigid-compulsive behaviors are associated with severe constipation and co-occurring diarrhea or underwear staining in children with autism spectrum disorder. Using data from the Autism Treatment Network, we evaluated the association between these gastrointestinal symptoms and measures of rigid compulsive behavior in children ages 2-17. Following statistical correction, four of five primary measures were significantly associated with constipation and diarrhea or underwear staining, including parental report of repetitive behavior, parental report of compulsive behavior, clinician diagnosis of obsessive-compulsive disorder, and report of rituals observed on the autism diagnostic observation schedule. This association could point to a causal connection between these symptoms or to a common biological pathway that impacts both gut and brain.

Bone density in peripubertal boys with autism spectrum disorders

We determined whether bone mineral density (BMD) is lower in boys with autism spectrum disorders (ASD) than controls, and also assessed variables that may affect BMD in ASD. BMD was measured using dual energy X-ray absorptiometry (DXA) in 18 boys with ASD and 19 controls 8-14 years old. Boys with ASD had lower BMD Z-scores at the spine, hip and femoral neck, and differences at the hip and femoral neck persisted after controlling for maturity and BMI. Vitamin D intake from food and in serum were lower in ASD subjects, as was exercise activity. We conclude that BMD is lower in peripubertal boys with ASD and may be associated with impaired vitamin D status and lower exercise activity.

Markers of Celiac Disease and Gluten Sensitivity in Children with Autism

OBJECTIVE

Gastrointestinal symptoms are a common feature in children with autism, drawing attention to a potential association with celiac disease or gluten sensitivity. However, studies to date regarding the immune response to gluten in autism and its association with celiac disease have been inconsistent. The aim of this study was to assess immune reactivity to gluten in pediatric patients diagnosed with autism according to strict criteria and to evaluate the potential link between autism and celiac disease.

METHODS

Study participants included children (with or without gastrointestinal symptoms) diagnosed with autism according to both the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview, Revised (ADI-R) (n = 37), their unaffected siblings (n = 27), and age-matched healthy controls (n = 76). Serum specimens were tested for antibodies to native gliadin, deamidated gliadin, and transglutaminase 2 (TG2). Affected children were genotyped for celiac disease associated HLA-DQ2 and -DQ8 alleles.

RESULTS

Children with autism had significantly higher levels of IgG antibody to gliadin compared with unrelated healthy controls (p<0.01). The IgG levels were also higher compared to the unaffected siblings, but did not reach statistical significance. The IgG anti-gliadin antibody response was significantly greater in the autistic children with gastrointestinal symptoms in comparison to those without them (p<0.01). There was no difference in IgA response to gliadin across groups. The levels of celiac disease-specific serologic markers, i.e., antibodies to deamidated gliadin and TG2, did not differ between patients and controls. An association between increased anti-gliadin antibody and presence of HLA-DQ2 and/or -DQ8 was not observed.

CONCLUSIONS

A subset of children with autism displays increased immune reactivity to gluten, the mechanism of which appears to be distinct from that in celiac disease. The increased anti-gliadin antibody response and its association with GI symptoms points to a potential mechanism involving immunologic and/or intestinal permeability abnormalities in affected children.

Brief report: Association between behavioral features and gastrointestinal problems among children with autism spectrum disorder

Recent reports suggest certain behaviors among children with autism spectrum disorders (ASD) may indicate underlying gastro-intestinal (GI) problems, and that the presence of these behaviors may help alert primary care providers to the need to evaluate a child with ASD for GI problems. The purpose of this population-based study of 487 children with ASD, including 35 (7.2%) with a medically documented history of GI problems, was to compare behavioral features of children with and without a history of GI problems. Unusual sleeping or eating habits and oppositional behavior were significantly associated with GI problems. These behaviors, however, were frequent in both children with and without GI problems, suggesting they may have limited utility in a screening capacity for GI problems.

Non-celiac gluten sensitivity

Gluten sensitivity has been best recognized and understood in the context of two conditions, celiac disease and wheat allergy. However, some individuals complain of symptoms in response to ingestion of "gluten," without histologic or serologic evidence of celiac disease or wheat allergy. The term non-celiac gluten sensitivity (NCGS) has been suggested for this condition, although a role for gluten proteins as the sole trigger of the associated symptoms remains to be established. This article reviews the available information regarding symptomatology, epidemiology and genetics, serology and histology, and in vitro and in vivo experimental data on the pathophysiology of NCGS.

Neurologic and psychiatric manifestations of celiac disease and gluten sensitivity

Celiac Disease (CD) is an immune-mediated disease dependent on gluten (a protein present in wheat, rye or barley) that occurs in about 1% of the population and is generally characterized by gastrointestinal complaints. More recently the understanding and knowledge of gluten sensitivity (GS), has emerged as an illness distinct from celiac disease with an estimated prevalence 6 times that of CD. Gluten sensitive people do not have villous atrophy or antibodies that are present in celiac disease, but rather they can test positive for antibodies to gliadin. Both CD and GS may present with a variety of neurologic and psychiatric co-morbidities, however, extraintestinal symptoms may be the prime presentation in those with GS. However, gluten sensitivity remains undertreated and underrecognized as a contributing factor to psychiatric and neurologic manifestations. This review focuses on neurologic and psychiatric manifestations implicated with gluten sensitivity, reviews the emergence of gluten sensitivity distinct from celiac disease, and summarizes the potential mechanisms related to this immune reaction.

Autism spectrum disorders: from immunity to behavior

Autism spectrum disorders (ASD) are complex and heterogeneous with a spectrum of diverse symptoms. Mounting evidence from a number of disciplines suggests a link between immune function and ASD. Although the causes of ASD have yet to be identified, genetic studies have uncovered a host of candidate genes relating to immune regulation that are altered in ASD, while epidemiological studies have shown a relationship with maternal immune disturbances during pregnancy and ASD. Moreover, decades of research have identified numerous systemic and cellular immune abnormalities in individuals with ASD and their families. These include changes in immune cell number, differences in cytokine and chemokine production, and alterations of cellular function at rest and in response to immunological challenge. Many of these changes in immune responses are associated with increasing impairment in behaviors that are core features of ASD. Despite this evidence, much remains to be understood about the precise mechanism by which the immune system alters neurodevelopment and to what extent it is involved in the pathogenesis of ASD. With estimates of ASD as high as 1% of children, ASD is a major public health issue. Improvements in our understanding of the interactions between the nervous and immune system during early neurodevelopment and how this interaction is different in ASD will have important therapeutic implications with wide ranging benefits.

Autoimmune and gastrointestinal dysfunctions: does a subset of children with autism reveal a broader connection?

A large number of autoimmune disorders have a gastrointestinal (GI) dysfunction component that may interplay with genetic, hormonal, environmental and/or stress factors. This narrarive review investigates possible links between autism, immune system abnormalities and GI symptoms in a subgroup of children with autism. A literature search on Medline (1950 to September 2010) was conducted to identify relevant articles by using the keywords 'autism and gastrointestinal' (71 publications) and 'autism and immune' (237 publications), cross-referencing and general searching to evaluate the available literature on the immunological and GI aspects of autism. Sufficient evidence exists to support that a subgroup of children with autism may suffer from concomitant immune-related GI symptoms.

Autism spectrum disorders are associated with an elevated autoantibody response to tissue transglutaminase-2

We report that a significant number of autistic children have serum levels of IgA antibodies above normal to the enzyme tissue transglutaminase II (TG2), and that expression of these antibodies to TG2 is linked to the (HLA)-DR3, DQ2 and DR7, DQ2 haplotypes. TG2 is expressed in the brain, where it has been shown to be important in cell adhesion and synaptic stabilization. Thus, these children appear to constitute a subpopulation of autistic children who fall within the autism disease spectrum, and for whom autoimmunity may represent a significant etiological component of their autism.

Autism spectrum disorders and allergy: observation from a pediatric allergy/immunology clinic

IgE-mediated allergic diseases (e.g., allergic rhinoconjunctivitis, atopic asthma and food allergy) are prevalent (up to 30%) in the general population and are increasing in developed countries. In infants and young children, non-IgE-mediated food allergy is also prevalent. In addition to easily recognized organ-specific symptoms, allergic diseases can cause neuropsychiatric symptoms, such as irritability and hyperactivity, in otherwise healthy individuals. This is also likely to occur in children with autism spectrum disorder (ASD). Moreover, the discomfort and pain associated with allergic diseases could aggravate behavioral symptoms in ASD children. Allergic conditions are easily treatable; however, ASD children may be underdiagnosed and/or undertreated for allergic and other common childhood diseases, in part due to their impaired communication skills. Practicing physicians should be aware of the potential impact of allergic diseases on behavioral symptoms and cognitive activity in ASD children. However, they also need to be aware that certain symptoms often attributed to 'allergy' by caregivers may not be immune mediated and should understand that behavioral symptoms can also be affected by many non-IgE-mediated causes.

Immune dysfunction in autism: a pathway to treatment

Autism is a complex and clinically heterogeneous disorder with a spectrum of symptoms. Clinicians, schools, and service agencies worldwide have reported a dramatic increase in the number of children identified with autism. Despite expanding research, the etiology and underlying biological processes of autism remain poorly understood, and the relative contribution from genetic, epigenetic, and environmental factors remains unclear. Although autism affects primarily brain function (especially affect, social functioning, and cognition), it is unknown to what extent other organs and systems are disrupted. Published findings have identified widespread changes in the immune systems of children with autism, at both systemic and cellular levels. Brain specimens from autism subjects exhibit signs of active, ongoing inflammation, as well as alterations in gene pathways associated with immune signaling and immune function. Moreover, many genetic studies have indicated a link between autism and genes that are relevant to both the nervous system and the immune system. Alterations in these pathways can affect function in both systems. Together, these reports suggest that autism may in fact be a systemic disorder with connections to abnormal immune responses. Such immune system dysfunction may represent novel targets for treatment. A better understanding of the involvement of the immune response in autism, and of how early brain development is altered, may have important therapeutic implications.

Contributions of the environment and environmentally vulnerable physiology to autism spectrum disorders

PURPOSE OF REVIEW

This review presents a rationale and evidence for contributions of environmental influences and environmentally vulnerable physiology to autism spectrum disorders (ASDs).

RECENT FINDINGS

Recent studies suggest a substantial increase in ASD prevalence above earlier Centers for Disease Control figures of one in 150, only partly explicable by data artifacts, underscoring the possibility of environmental contributors to increased prevalence. Some gene variants in ASD confer altered vulnerability to environmental stressors and exposures. De-novo mutations and advanced parental age as a risk factor for ASD also suggest a role for environment. Systemic and central nervous system pathophysiology, including oxidative stress, neuroinflammation, and mitochondrial dysfunction can be consistent with a role for environmental influence (e.g. from air pollution, organophosphates, heavy metals) in ASD, and some of the underlying biochemical disturbances (such as abnormalities in glutathione, a critical antioxidant and detoxifier) can be reversed by targeted nutritional interventions. Dietary factors and food contaminants may contribute risk. Improvement and loss of diagnosis in some with ASD suggest brain circuitry amenable to environmental modulation.

SUMMARY

Prevalence, genetic, exposure, and pathophysiological evidence all suggest a role for environmental factors in the inception and lifelong modulation of ASD. This supports the need for seeking targets for early and ongoing medical prevention and treatment of ASD.

Medical treatment of autism spectrum disorders

PURPOSE OF REVIEW

There are several common medical conditions occurring in people with autism spectrum disorders (ASD) that can benefit from treatment and can in turn improve the health and quality of life of people with ASD. This review will primarily focus on these medical comorbidities, with a brief review of potential future treatments.

RECENT FINDINGS

There continues to be disagreement regarding the exact prevalence and etiological significance of gastrointestinal conditions, epilepsy and other abnormal electroencephalographic findings, and sleep problems. It is not clear whether gastrointestinal conditions occur more frequently than in typically developing children, and whether there are distinct conditions that occur more often in ASD than in non-ASD populations. Abnormal electroencephalographic findings have been reported in up to 60% of children with ASD, and some believe that these abnormalities may be responsible for parts of the ASD phenotype. Sleep problems are reported more frequently than in the general population, and effective treatments are available. Future medical treatments for ASD may be directed at underlying core symptoms and have greater impact than today's symptomatic approach.

SUMMARY

Further research in these areas is needed to better guide diagnosis and treatment of a variety of medical conditions experienced by people with ASD.

A longitudinal study of gastrointestinal diseases in individuals diagnosed with infantile autism as children

BACKGROUND

A number of studies have indicated a link between gastrointestinal (GI) diseases and autism spectrum disorders.

METHOD

The objective of this study was to compare the prevalence and types of GI diseases in a clinical sample of 118 individuals diagnosed as children with infantile autism (IA) with GI diseases in 336 matched controls from the general population, based on data from the nationwide Danish National Hospital Register (DNHR). The average observation time was 30.3 years (SD 0.4) (range 27-30 years), and mean age at the end of the observation period was 42.7 years (SD 7.7) (range between 27 and 57 years of age).

RESULTS

Of the 118 individuals with IA, 97 (82.2%) had been in contact with a medical hospital (inpatient hospitalization or outpatient visits) during the observation period, compared with 312/336 (92.9%) in the control group (P= 0.001). A similar proportion of members from the case and comparison group had a diagnosis of any GI disease in the DNHR: 30.5% against 30.7%, but the nature of their diseases may be somewhat different. Only diseases of oral cavity were significantly associated with IA: 20.3% against 1.2%, P < 0.0001. Otherwise, specific GI diseases occurred with low frequency in both groups.

CONCLUSION

Overall, no evidence was found that patients with IA were more likely than control persons without IA to have defined GI diseases during the 30.3-year observation period.