A lack of association between elevated serum levels of S100B protein and autoimmunity in autistic children

Lipopolysaccharide impairs neurodevelopment and induces changes in astroglial reactivity, antioxidant defenses and bioenergetics in the cerebral cortex of neonatal rats

Neonates have an immature immune system, which increases their vulnerability to infectious agents and inflammatory insults. The administration of the immunostimulatory agent lipopolysaccharide (LPS) has been shown to induce the expression of pro-inflammatory cytokines and cause behavior alterations in rodents at different ages. However, the effects of LPS administration during the neonatal period and its consequences during immune system maturation remain to be elucidated. We showed here that a single intraperitoneal administration of LPS in rats on postnatal day (PND) 7 caused early and variable alterations in TNF-α, S100B and GFAP levels in the cerebral cortex, CSF and serum of the animals, indicating long-term induction of neuroinflammation and astroglial reactivity. However, on PND 21, only GFAP levels were increased by LPS. Additionally, LPS induced oxidative stress and altered energy metabolism enzymes in the cerebral cortex on PND 21, and caused neurodevelopment impairment over time. These data suggest that neuroinflammation induction during the neonatal period induces glial reactivity, oxidative stress and bioenergetic disruption that may lead to neurodevelopment impairment and cognitive deficit in adult life.

Neurovascular crosstalk and cerebrovascular alterations: an underestimated therapeutic target in autism spectrum disorders

Normal brain development, function, and aging critically depend on unique characteristics of the cerebrovascular system. Growing evidence indicated that cerebrovascular defects can have irreversible effects on the brain, and these defects have been implicated in various neurological disorders, including autism spectrum disorder (ASD). ASD is a neurodevelopmental disorder with heterogeneous clinical manifestations and anatomical changes. While extensive research has focused on the neural abnormalities underlying ASD, the role of brain vasculature in this disorder remains poorly understood. Indeed, the significance of cerebrovascular contributions to ASD has been consistently underestimated. In this work, we discuss the neurovascular crosstalk during embryonic development and highlight recent findings on cerebrovascular alterations in individuals with ASD. We also discuss the potential of vascular-based therapy for ASD. Collectively, these investigations demonstrate that ASD can be considered a neurovascular disease.

Astrocyte responses to postnatal erythropoietin and nano-erythropoietin treatments in a valproic acid-induced animal model of autism

BACKGROUND

Despite ample evidence of the potential protective effects of erythropoietin (EPO) on the developing brain, no study has addressed the effects of postnatal EPO on behaviors and brain tissue of animal models of autism. In the present study, we examined the therapeutic effects of postnatal erythropoietin on stereotypic behaviors and astrocyte responses via glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100B) immunohistochemistry in a valproic acid (VPA) animal model of autism. Also, we compared the effects of EPO with EPO-loaded solid lipid nanoparticles (NEPO) because the blood-brain barrier has limited permeability to EPO.

METHODS

Pregnant rats received a single dose of VPA (600mg/kg) at gestational day 12.5. EPO (2000U/kg) and EPO-loaded solid lipid nanoparticles (NEPO1000 and 2000U/kg) were injected intraperitoneally from postnatal days 1-5. Repetitive behaviors in male offspring were assessed by a marble burying test. The immune-staining method was performed to evaluate S100B and GFAP-positive cells in the prefrontal cortex and hippocampal CA1 region.

RESULTS

VPA animal models revealed more repetitive behavior and displayed higher astrogliosis in the prefrontal cortex (PFC) and hippocampus (CA1) regions. The repetitive behaviors were ameliorated relatively in VPA groups with NEPO2000 treatment, and astrogliosis was reduced even when VPA rats were treated with a lower dosage of NEPO.

CONCLUSION

Our results indicate beneficial effects of postnatal NEPO exposure in the VPA animal model of autism, which proposes it as an early treatment in infants with, or at risk of, autism.

A perspective on molecular signalling dysfunction, its clinical relevance and therapeutics in autism spectrum disorder

Intellectual disability (ID) and autism spectrum disorder (ASD) are neurodevelopmental disorders that have become a primary clinical and social concern, with a prevalence of 2-3% in the population. Neuronal function and behaviour undergo significant malleability during the critical period of development that is found to be impaired in ID/ASD. Human genome sequencing studies have revealed many genetic variations associated with ASD/ID that are further verified by many approaches, including many mouse and other models. These models have facilitated the identification of fundamental mechanisms underlying the pathogenesis of ASD/ID, and several studies have proposed converging molecular pathways in ASD/ID. However, linking the mechanisms of the pathogenic genes and their molecular characteristics that lead to ID/ASD has progressed slowly, hampering the development of potential therapeutic strategies. This review discusses the possibility of recognising the common molecular causes for most ASD/ID based on studies from the available models that may enable a better therapeutic strategy to treat ID/ASD. We also reviewed the potential biomarkers to detect ASD/ID at early stages that may aid in diagnosis and initiating medical treatment, the concerns with drug failure in clinical trials, and developing therapeutic strategies that can be applied beyond a particular mutation associated with ASD/ID.

Demonstration of Ameliorating Effect of Vardenafil Through Its Anti-Inflammatory and Neuroprotective Properties in Autism Spectrum Disorder Induced by Propionic Acid on Rat Model

Introduction: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with complex etiology. In this study, we aimed to determine the ameliorating effects of vardenafil in the ASD rat model induced by propionic acid (PPA) in terms of neurobehavioral changes and also support these effects with histopathological changes, brain biochemical analysis and magnetic resonance spectroscopy (MRS) findings.Materials and Methods: Twenty-one male rats were randomly assigned into 3 groups. Group 1 (control, 7 rats) did not receive treatment. Rats in groups 2 and 3 were given PPA at the dose of 250 mg/kg/day intraperitoneally for 5 days. After PPA administration, animals in group 2 (PPAS, 7 rats) were given saline and animals in group 3 (PPAV, 7 rats) were given vardenafil. Behavioral tests were performed between the 20th and 24th days of the study. The rats were taken for MRS on the 25^th day. At the end of the study, brain levels of interleukin-2 (IL-2), IL-17, tumor necrosis factor-α, nerve growth factor, cGMP and lactate levels were measured. In the cerebellum and the CA1 and CA3 regions of the hippocampus, counts of neurons and Purkinje cells and glial fibrillary acidic protein (associated with gliosis) were evaluated histologically.Results: Three chamber sociability and passive avoiding test, histopathological results, lactate levels derived from MRS, and biochemical biomarkers revealed significant differences among the PPAV and PPAS groups.Conclusion: We concluded that vardenafil improves memory and social behaviors and prevent loss of neuronal and Purkinje cell through its anti-inflammatory and neuroprotective effect.

S100B dysregulation during brain development affects synaptic SHANK protein networks via alteration of zinc homeostasis

Autism Spectrum Disorders (ASD) are caused by a combination of genetic predisposition and nongenetic factors. Among the nongenetic factors, maternal immune system activation and zinc deficiency have been proposed. Intriguingly, as a genetic factor, copy-number variations in S100B, a pro-inflammatory damage-associated molecular pattern (DAMP), have been associated with ASD, and increased serum S100B has been found in ASD. Interestingly, it has been shown that increased S100B levels affect zinc homeostasis in vitro. Thus, here, we investigated the influence of increased S100B levels in vitro and in vivo during pregnancy in mice regarding zinc availability, the zinc-sensitive SHANK protein networks associated with ASD, and behavioral outcomes. We observed that S100B affects the synaptic SHANK2 and SHANK3 levels in a zinc-dependent manner, especially early in neuronal development. Animals exposed to high S100B levels in utero similarly show reduced levels of free zinc and SHANK2 in the brain. On the behavioral level, these mice display hyperactivity, increased stereotypic and abnormal social behaviors, and cognitive impairment. Pro-inflammatory factors and zinc-signaling alterations converge on the synaptic level revealing a common pathomechanism that may mechanistically explain a large share of ASD cases.

Peripheral Blood S100B Levels in Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

The S100 calcium-binding protein beta subunit (S100B) protein, which mostly exists in the central nervous system, is commonly noted as a marker of neuronal damage. We conducted the first systematic review with meta-analysis to compare peripheral blood S100B levels in individuals with ASD with those in healthy controls. A systematic search was carried out for studies published before May 5, 2020. In total, this meta-analysis involved ten studies with 822 participants and 451 cases. The meta-analysis revealed that individuals with ASD had higher peripheral blood S100B levels than healthy controls [standardized mean difference (SMD) = 0.97, 95% confidence interval (95% CI) = 0.41–1.53; p < 0.001]. Peripheral blood S100B levels may have potential as a useful biomarker for ASD.

High Serum Levels of Serum 100 Beta Protein, Neuron-specific Enolase, Tau, Active Caspase-3, M30 and M65 in Children with Autism Spectrum Disorders

Objective

The purpose of this study was therefore to investigate whether neuronal, axonal, and glial cell markers (Neuron-specific enolase [NSE], tau, serum 100 beta protein [S100B], respectively) and apoptosis markers (active caspase 3, M30, M65) and whether these parameters can be used as diagnostic biomarkers in autism spectrum disorders (ASD).

Methods

This study measured the serum S100B, NSE, tau, active caspase 3, M30, and M65 levels in 43 patients with ASD (aged 3−12 years) and in 41 age- and sex-matched healthy controls. ASD severity was rated using the Childhood Autism Rating Scale. The serum levels were determined in the biochemistry laboratory using the ELISA technique. The receiver operator characteristics curve method was employed to evaluate the accuracy of the parameters in diagnosing ASD.

Results

Serum S100B, tau, NSE, active caspase-3, M30, and M65 levels were significantly higher in the patient group than in the control group (p < 0.001, p = 0.002, p = 0.002, p = 0.005, p < 0.001, and p = 0.004, respectively). The cut-off value of S100B was 48.085 pg/ml (sensitivity: 74.4%, specificity: 80.5%, areas under the curve: 0.879, p < 0.001).

Conclusion

Apoptosis increased in children with ASD, and neuronal, axonal, and glial cell injury was observed. In addition, S100B may be an important diagnostic biomarker in patients with ASD. Apoptosis, and neuronal, axonal and astrocyte pathologies may play a significant role in the pathogenesis of ASD, and further studies are now required to confirm this.

Chronic maternal interleukin-17 and autism-related cortical gene expression, neurobiology, and behavior

Chronic inflammation during pregnancy (e.g., preeclampsia, diabetes) is linked to increased risk for offspring neurodevelopmental disorders such as autism spectrum disorder (ASD). However, mediators of such exposures that could be targeted with maternal intervention are unclear, as few chronic gestational inflammation models have been tested. One potential mediator is interleukin-17 (IL-17), a pro-inflammatory cytokine implicated in neurodevelopmental disorders and gestational disease. To test chronic maternal IL-17 impacts on offspring, C57BL/6J dams were administered IL-17A continuously throughout pregnancy. Offspring were assessed for body weight; cortical volume, gene expression, and cellular composition; and adult behavior. IL-17A-condition offspring exhibited decreased somatic and cortical size at embryonic day 18 (E18) and as adults. mRNA sequencing of E18 cortex revealed 320 differentially expressed genes in males, but none in females. These were significantly enriched for ASD (Simons Foundation Autism Research Initiative), synaptic, and cell cycle genes. By adulthood, neocortical glial cell density and gene expression were decreased, while GABAergic synaptic gene expression was increased in males. Furthermore, IL-17A-condition male but not female offspring exhibited reduced anxiety-like behavior. Social approach deficits in males were negatively correlated with neocortical GABAergic synaptic gene expression. Chronic gestational IL-17A was sufficient to cause ASD-like phenotypes early and persistently in male offspring. This echoes the male bias, altered cortical development, and behavioral findings in ASD, suggesting that chronic maternal IL-17 contributes to offspring ASD pathogenesis. Furthermore, the trajectory from embryonically dysregulated synaptic and cell cycle genes to disrupted adult glia, inhibitory synapses, and behavior suggests a mechanism for chronic maternal IL-17 effects on offspring.

Probiotics and oxytocin nasal spray as neuro-social-behavioral interventions for patients with autism spectrum disorders: a pilot randomized controlled trial protocol

Background

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by impairments in social interaction and communication. Oxytocin (OXT), as a neuropeptide, plays a role in emotional and social behaviors. Lactobacillus reuteri (L. reuteri) supplementation led to an OXT-dependent behavioral improvement in ASD mouse models. Despite some promising results from animal studies, little is known about the efficacy of supplementation with L. reuteri, alone or with exogenous OXT therapy, on social-behavioral functions in ASD patients. This paper presents a protocol for a pilot randomized controlled trial to evaluate the feasibility of conducting a full trial comparing oral supplementation of L. reuteri probiotics and intranasal OXT spray to placebo on the effect of social and behavioral functions in ASD patients. The study will also capture preliminary estimates of the efficacy of the proposed interventions in ASD patients.

Methods

This pilot trial is a two-staged, randomized, double-blind, placebo-controlled, parallel-group study. Throughout the study (0-24 weeks), 60 patients with ASD will be randomly assigned to receive either oral L. reuteri probiotics or placebo. In the second study stage (13-24 weeks), all participants will receive intranasal OXT spray. As primary outcomes, serum OXT levels will be assayed and social behaviors will be assessed via the Autism Behavior Checklist and the Social Responsiveness Scale which are validated questionnaires, an objective emotional facial matching test, and a new video-based eye-tracking test. Secondary outcomes include the GI-severity-index and Bristol Stool Chart to assess GI function and gut microbiome/short-chain fatty acids. All the outcomes will be assessed at baseline and weeks 12 and 24.

Discussion

This pilot study will provide important information on the feasibility of recruitment, blinding and concealment, treatment administration, tolerability and adherence, specimen collection, outcome assessment, potential adverse effects, and the preliminary efficacy on both primary and secondary outcomes. If successful, this pilot study will inform a larger randomized controlled trial fully powered to examine the efficacies of oral L. reuteri probiotics and/or intranasal OXT spray on social-behavioral improvement in ASD patients.

Trial registration

ClinicalTrials.gov, NCT03337035. Registered 8 November 2017.

The influence of neuroinflammation in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by deficits in social communication and restricted or repetitive behaviours. The clinical presentation of ASD is highly variable and diagnosis is based on the presence of impaired social communication and repetitive and/or restricted behaviours. Although the precise pathophysiologies underlying ASD are unclear, growing evidence supports a role for dysregulated neuroinflammation. The potential involvement of microglia and astrocytes reactive to inflammatory stimuli in ASD has generated much interest due to their varied roles including in mounting an immune response and regulating synaptic function. Increased numbers of reactive microglial and astrocytes in both ASD postmortem tissue and animal models have been reported. Whether dysregulation of glial subtypes exacerbates alterations in neural connectivity in the brain of autistic patients is not well explored. A role for the gut-brain axis involving microbial-immune-neuronal cross talk is also a growing area of neuroinflammation research. Greater understanding of these interactions under patho/physiological conditions and the identification of consistent immune profile abnormalities can potentially lead to more reliable diagnostic measures and treatments in ASD.

Do Alarmins Have a Potential Role in Autism Spectrum Disorders Pathogenesis and Progression?

Autism spectrum disorders (ASDs) represent a disabling condition in early childhood. A number of risk factors were proposed in order to explain their pathogenesis. A multifactorial model was proposed, and data supported the implication of genetic and environmental factors. One of the most accepted speculations is the existence of an imbalance of the immune system. Altered levels of cytokines, chemokines and immunoglobulins were demonstrated in patients with ASDs; in particular, proinflammatory mediators were significantly increased. Alarmins are a multifunctional heterogeneous group of proteins, structurally belonging to specific cells or incorporated by them. They are released in the surrounding tissues as a consequence of cell damage or inflammation. Their functions are multiple as they could activate innate immunity or recruit and activate antigen-presenting cells stimulating an adaptive response. Alarmins are interesting both for understanding the inflammatory process and for diagnostic purposes as biomarkers. Moreover, recent studies, separately, showed that alarmins like interleukin (IL)-33, high-mobility group box 1 (HMGB1), heat-shock protein (HSP) and S100 protein (S100) could play a relevant role in the pathogenesis of ASDs. According to the literature, some of these alarmins could be suitable as biomarkers of inflammation in ASD. Other alarmins, by interfering with the immune system blocking pro-inflammatory mediators, could be the key for ameliorating symptoms and behaviours in autistic disorders.

A systematic review of gut-immune-brain mechanisms in Autism Spectrum Disorder

Despite decades of research, the etiological origins of Autism Spectrum Disorder (ASD) remain elusive. Recently, the mechanisms of ASD have encompassed emerging theories involving the gastrointestinal, immune, and nervous systems. While each of these perspectives presents its own set of supporting evidence, the field requires an integration of these modular concepts and an overarching view of how these subsystems intersect. In this systematic review, we have synthesized relevant evidences from the existing literature, evaluating them in an interdependent manner and in doing so, outlining their possible connections. Specifically, we first discussed gastrointestinal and immuno-inflammation pathways in-depth, exploring the relationships between microbial composition, bacterial metabolites, gut mucosa, and immune system constituents. Accounting for temporal differences in the mechanisms involved in neurodevelopment, prenatal and postnatal phases were further elucidated, where the former focused on maternal immune activation (MIA) and fetal development, while the latter addressed the role of immune dysregulation in contributing to atypical neurodevelopment. As autism remains, foremost, a neurodevelopmental disorder, this review presents an integration of disparate modules into a "Gut-Immune-Brain" paradigm. Existing gaps in the literature have been highlighted, and possible avenues for future research with an integrated physiological perspective underlying ASD have also been suggested.

Blood-brain barrier regulation in psychiatric disorders

The blood-brain barrier (BBB) is a dynamic interface between the peripheral blood supply and the cerebral parenchyma, controlling the transport of material to and from the brain. Tight junctions between the endothelial cells of the cerebral microvasculature limit the passage of large, negatively charged molecules via paracellular diffusion whereas transcellular transportation across the endothelial cell is controlled by a number of mechanisms including transporter proteins, endocytosis, and diffusion. Here, we review the evidence that perturbation of these processes may underlie the development of psychiatric disorders including schizophrenia, autism spectrum disorder (ASD), and affective disorders. Increased permeability of the BBB appears to be a common factor in these disorders, leading to increased infiltration of peripheral material into the brain culminating in neuroinflammation and oxidative stress. However, although there is no common mechanism underpinning BBB dysfunction even within each particular disorder, the tight junction protein claudin-5 may be a clinically relevant target given that both clinical and pre-clinical research has linked it to schizophrenia, ASD, and depression. Additionally, we discuss the clinical significance of the BBB in diagnosis (genetic markers, dynamic contrast-enhanced-magnetic resonance imaging, and blood biomarkers) and in treatment (drug delivery).

Elevated plasma concentrations of S100 calcium-binding protein B and tumor necrosis factor alpha in children with autism spectrum disorders

Objective:

To investigate plasma concentrations of S100B (a calcium-binding protein derived primarily from the glia) and inflammatory cytokines in children with autism and the relationship between S100B and cytokine concentrations.

Methods:

Plasma levels of S100B, tumor necrosis factor alpha (TNF-α), interferon gamma, interleukin (IL)-1β, IL-4, IL-6, IL-10, and IL-17A were measured in 40 unmedicated children with autism and 35 normally developing healthy children. The severity of autism was assessed using the Childhood Autism Rating Scale (CARS).

Results:

Concentrations of both S100B and TNF-α were higher in children with autism before and after adjusting for a priori-selected confounders (age, sex, and body mass index). S100B concentrations were higher in children with severe autism compared to children with mild-moderate autism. However, this association remained as a trend after adjusting for confounders. S100B concentrations correlated positively with TNF-α concentrations.

Conclusion:

Our findings showing an increase in peripheral concentrations of S100B and TNF-α provide limited support to the hypothesis about the roles of altered immune function and S100B in autism spectrum disorder (ASD). Studies of larger numbers of well-characterized individuals with ASD are needed to clarify the potential role of the immune system in the pathophysiology of this disorder.

Peripheral Inflammatory Markers Contributing to Comorbidities in Autism

This study evaluates the contribution of peripheral biomarkers to comorbidities and clinical findings in autism. Seventeen autistic children and age-matched typically developing (AMTD), between three to nine years old were evaluated. The diagnostic followed the Diagnostic and Statistical Manual of Mental Disorders 4th Edition (DMS-IV) and the Childhood Autism Rating Scale (CARS) was applied to classify the severity. Cytokine profile was evaluated in plasma using a sandwich type ELISA. Paraclinical events included electroencephalography (EEG) record. Statistical analysis was done to explore significant differences in cytokine profile between autism and AMTD groups and respect clinical and paraclinical parameters. Significant differences were found to IL-1β, IL-6, IL-17, IL-12p40, and IL-12p70 cytokines in individuals with autism compared with AMTD (p < 0.05). All autistic patients showed interictalepileptiform activity at EEG, however, only 37.5% suffered epilepsy. There was not a regional focalization of the abnormalities that were detectable with EEG in autistic patients with history of epilepsy. A higher IL-6 level was observed in patients without history of epilepsy with interictalepileptiform activity in the frontal brain region, p < 0.05. In conclusion, peripheral inflammatory markers might be useful as potential biomarkers to predict comorbidities in autism as well as reinforce and aid informed decision-making related to EEG findings in children with Autism spectrum disorders (ASD).

The positive association between elevated blood lead levels and brain-specific autoantibodies in autistic children from low lead-polluted areas

The underlying pathogenic mechanism in autoimmune disorders is the formation of autoantibodies. In children with autism spectrum disorder (ASD), it has been documented increased levels of brain-specific autoantibodies. Furthermore, lead (Pb) has been identified as one of the main neurotoxicants acting as environmental triggers for ASD as it induces neuroinflammation and autoimmunity. The present study is the first to explore a potential relationship between the levels of blood lead (BPb) and seropositivity of anti-ribosomal P protein antibodies in ASD children. Levels of BPb and serum anti-ribosomal P protein antibodies were measured in 60 children with ASD and 60 healthy control matched children, aged between 5 and 12 years, recruited from low Pb-polluted areas. The levels of BPb were significantly higher in ASD children than in healthy control children (P < 0.001). Patients with ASD had significantly higher frequency of increased BPb levels ≥10 μg/dL (43.3 %) than healthy control children (13.3 %; P < 0.001). There were significant and positive correlations between the levels of BPb, and the values of Childhood Autism Rating Scale (CARS) (P < 0.01) and IQ in children with ASD (P < 0.001). Patients with ASD showing increased levels of BPb had significantly higher frequency of seropositivity of anti-ribosomal P antibodies (92.3 %) than patients with normal BPb levels (32.3 %; P < 0.001). The findings of the present study suggest that increased levels of BPb in some children with ASD may trigger the production of serum anti-ribosomal P antibodies. Further research is warranted to determine if the production of brain autoantibodies is triggered by environmental Pb exposure in children with ASD. The possible therapeutic role of Pb chelators in ASD children should also be studied.

Association between Asthma and Autism Spectrum Disorder: A Meta-Analysis

Objective

We conducted a meta-analysis to summarize the evidence from epidemiological studies of the association between asthma and autism spectrum disorder (ASD).

Methods

A literature search was conducted using PubMed, Embase, and Cochrane library for studies published before February 2nd, 2016. Observational studies investigating the association between asthma and ASD were included. A random effects model was used to calculate the pooled risk estimates for the outcome. Subgroup analysis was used to explore potential sources of heterogeneity and publication bias was estimated using Begg's and Egger's tests.

Results

Ten studies encompassing 175,406 participants and 8,809 cases of ASD were included in this meta-analysis. In the cross-sectional studies, the prevalence of asthma in ASD was 20.4%, while the prevalence of asthma in controls was 15.4% (P < 0.001). The pooled odds ratio (OR) for the prevalence of asthma in ASD in the cross-sectional studies was 1.26 (95% confidence interval (CI): 0.98–1.61) (P = 0.07), with moderate heterogeneity (I² = 65.0%, P = 0.02) across studies. In the case-control studies, the pooled OR for the prevalence of asthma in ASD was 0.98 (95% CI: 0.68–1.43) (P = 0.94), and there was no evidence of an association between asthma and ASD. No evidence of significant publication bias on the association between asthma and ASD was found.

Conclusions

In conclusion, the results of this meta-analysis do not suggest an association between asthma and ASD. Further prospective studies ascertaining the association between asthma and ASD are warranted.

Activity-Regulated Cytoskeleton-Associated Protein Dysfunction May Contribute to Memory Disorder and Earlier Detection of Autism Spectrum Disorders

OBJECTIVE

To explore a possible role for activity-regulated cytoskeleton-associated (Arc/Arg3.1) protein in the clinical identification of children with autism.

SUBJECTS AND METHODS

The plasma levels of Arc/Arg3.1 in 62 boys with autism and 32 healthy boys were measured using an enzyme-linked immunosorbent assay (ELISA). The Childhood Autism Rating Scale (CARS) was used to assess the severity of autism as defined in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV). The Mann-Whitney U test was used for comparisons between children with autism and healthy children. The Spearman r correlation coefficient (r) was used to determine the relationship between the CARS scores among patients with autism and different variables.

RESULTS

The mean plasma level of Arc/Arg3.1 protein in autism was 1.689 ± 0.917 pg/ml, significantly higher than that of healthy controls, i.e. 0.792 ± 1.056 pg/ml (p < 0.001). No significant relationship was found between plasma levels of Arc/Arg3.1 protein and CARS scores (r = -0.06; p > 0.05) or age (r = -0.27; p > 0.05).

CONCLUSIONS

The mean plasma level of Arc/Arg3.1 protein was higher in children with autism than in controls, suggesting that Arc/Arg3.1 could be a potential early blood biomarker for diagnosis of autism.

S100B Serum Levels Predict Treatment Response in Patients with Melancholic Depression

BACKGROUND

There is an ongoing search for biomarkers in psychiatry, for example, as diagnostic tools or predictors of treatment response. The neurotrophic factor S100 calcium binding protein B (S100B) has been discussed as a possible predictor of antidepressant response in patients with major depression, but also as a possible biomarker of an acute depressive state. The aim of the present study was to study the association of serum S100B levels with antidepressant treatment response and depression severity in melancholically depressed inpatients.

METHODS

After a wash-out period of 1 week, 40 inpatients with melancholic depression were treated with either venlafaxine or imipramine. S100B levels and Hamilton Depression Rating Scale (HAM-D) scores were assessed at baseline, after 7 weeks of treatment, and after 6 months.

RESULTS

Patients with high S100B levels at baseline showed a markedly better treatment response defined as relative reduction in HAM-D scores than those with low baseline S100B levels after 7 weeks (P=.002) and 6 months (P=.003). In linear regression models, S100B was a significant predictor for treatment response at both time points. It is of interest to note that nonresponders were detected with a predictive value of 85% and a false negative rate of 7.5%. S100B levels were not associated with depression severity and did not change with clinical improvement.

CONCLUSIONS

Low S100B levels predict nonresponse to venlafaxine and imipramine with high precision. Future studies have to show which treatments are effective in patients with low levels of S100B so that this biomarker will help to reduce patients' burden of nonresponding to frequently used antidepressants.

Increased production of IL-17 in children with autism spectrum disorders and co-morbid asthma

Inflammation and asthma have both been reported in some children with autism spectrum disorder (ASD). To further assess this connection, peripheral immune cells isolated from young children with ASD and typically developing (TD) controls and the production of cytokines IL-17, -13, and -4 assessed following ex vivo mitogen stimulation. Notably, IL-17 production was significantly higher following stimulation in ASD children compared to controls. Moreover, IL-17 was increased in ASD children with co-morbid asthma compared to controls with the same condition. In conclusion, children with ASD exhibited a differential response to T cell stimulation with elevated IL-17 production compared to controls.

Neurodevelopment and phenotype-modulating functions of S100B protein: a pilot study

The importance of certain neurotrophic proteins found in maternal blood and milk for breastfed infants has remained ambiguous. This study was conducted to present evidence of the impact of an induced deficit of active S100B protein on neonate development. Newborn mice from two groups of mothers, immunized or sham-immunized against S100B, were subjected to various behavioral tests, and the development of their morphological characteristics was recorded from birth until weaning. Morphological problems, including weight gain and fur coating, a delay in the maturation of neurobehavioral systems and a deficit in neuromotor functions, including visual abilities, somato-sensory and posture reactions, muscular strength, locomotion, and fear/orienting processes, were observed in pups of immunized mothers. The S100B protein of external or internal origin in infants may be considered to be a specific factor that determines neuro- and morphological development and a risk-avoidance ('homeward-bent' or fearful) phenotype. The suppression of activity of the S100B protein results in a slower neonatal development and the formation of a risk-tolerant (fearless) phenotype of the offspring. This study thus considers the mechanism of neuroplastic regulation on the extent of sensation-seeking or risk-taking (homeless-like or fearless) and sensation- or risk-avoidance (home-bound or fearful) features in individual phenotypes.

A possible association between elevated serum levels of brain-specific auto-antibodies and reduced plasma levels of docosahexaenoic acid in autistic children

Polyunsaturated fatty acids (PUFAs) are not only essential for energy production, but they also exhibit a range of immunomodulatory properties that progress through T cell mediated events. Autoimmunity may have a pathogenic role in a subgroup of autistic children. This study is the first to investigate the relationship between serum levels of anti-myelin basic protein (anti-MBP) brain-specific auto-antibodies and reduced plasma levels of PUFAs in autistic children. Plasma levels of PUFAs (including linoleic, alphalinolenic, arachidonic "AA" and docosahexaenoic "DHA" acids) and serum anti-MBP were measured in 80 autistic children, aged between 4 and 12 years, and 80 healthy-matched children. Autistic patients had significantly lower plasma levels of PUFAs than healthy children. On the other hand, ω6/ω3 ratio (AA/DHA) was significantly higher in autistic patients than healthy children. Low plasma DHA, AA, linolenic and linoleic acids were found in 67.5%, 50%, 40% and 35%, respectively of autistic children. On the other hand, 70% of autistic patients had elevated ω6/ω3 ratio. Autistic patients with increased serum levels of anti-MBP auto-antibodies (75%) had significantly lower plasma DHA (P<0.5) and significantly higher ω6/ω3 ratio (P<0.5) than patients who were seronegative for these antibodies. In conclusions, some autistic children have a significant positive association between reduced levels of plasma DHA and increased serum levels of anti-MBP brain-specific auto-antibodies. However, replication studies of larger samples are recommended to validate whether reduced levels of plasma PUFAs are a mere association or have a role in the induction of the production of anti-MBP in some autistic children.

Systemic auto-antibodies in children with autism

Autoimmunity to central nervous system may have a role in the pathogenesis of autism. A subset of anti-ds-DNA antibodies has been recently proved to be pathogenic to the brain as well as to the kidney. Due to the paucity of studies investigating the frequency of systemic auto-antibodies in autism, we are the first to investigate the frequency of anti-ds-DNA antibodies in a group of autistic children. The seropositivity of anti-nuclear antibodies (ANA) was also investigated. Serum anti-ds-DNA antibodies and ANA were measured in 100 autistic children, aged between 4 and 11 years, in comparison to 100 healthy-matched children. The seropositivity of anti-ds-DNA antibodies and ANA in autistic children was 34% and 25%, respectively. In addition, 42% of autistic children were seropositive for anti-ds-DNA antibodies and/or ANA. The frequencies of anti-ds-DNA antibodies and ANA in autistic children were significantly higher than that in healthy children (4% and 2%, respectively), (P<0.001 and P<0.001, respectively). Autistic children with a family history of autoimmunity (45%) had significantly higher frequency of serum anti-ds-DNA antibodies (48.9%) than patients without such a history (21.8%), P=0.008. There was a significant positive association between the seropositivity of anti-ds-DNA antibodies and ANA (P<0.001). In conclusion, anti-ds-DNA antibodies and ANA were found in the sera of a subgroup of autistic children. However, replication studies of larger samples are warranted to validate whether these antibodies are a mere association or have a pathogenic role in some autistic children.

Evidence linking oxidative stress, mitochondrial dysfunction, and inflammation in the brain of individuals with autism

Autism spectrum disorders (ASDs) are a heterogeneous group of neurodevelopmental disorders that are defined solely on the basis of behavioral observations. Therefore, ASD has traditionally been framed as a behavioral disorder. However, evidence is accumulating that ASD is characterized by certain physiological abnormalities, including oxidative stress, mitochondrial dysfunction and immune dysregulation/inflammation. While these abnormalities have been reported in studies that have examined peripheral biomarkers such as blood and urine, more recent studies have also reported these abnormalities in brain tissue derived from individuals diagnosed with ASD as compared to brain tissue derived from control individuals. A majority of these brain tissue studies have been published since 2010. The brain regions found to contain these physiological abnormalities in individuals with ASD are involved in speech and auditory processing, social behavior, memory, and sensory and motor coordination. This manuscript examines the evidence linking oxidative stress, mitochondrial dysfunction and immune dysregulation/inflammation in the brain of ASD individuals, suggesting that ASD has a clear biological basis with features of known medical disorders. This understanding may lead to new testing and treatment strategies in individuals with ASD.

Serum antinucleosome-specific antibody as a marker of autoimmunity in children with autism

Background

Increasing evidence of autoimmune phenomena in some individuals with autism could represent the presence of altered or inappropriate immune responses in this disorder. The role of the nucleosome in the induction of antibody response in some autoimmune-mediated tissue damage may provide novel targets for treatment. Due to the paucity of studies investigating the frequency of systemic auto-antibodies in autism, we are the first to investigate the frequency of antinucleosome-specific antibodies in a group of autistic children.

Methods

Serum antinucleosome-specific antibodies were measured by ELISA in 60 autistic children, between the ages of 3 and 12 years, in comparison to 60 healthy children. Autistic severity was assessed using the Childhood Autism Rating Scale (CARS).

Results

Autistic children had significantly higher serum antinucleosome-specific antibodies than healthy children (P <0.001). The seropositivity of antinucleosome-specific antibodies was found in 46.7% of autistic children. Autistic children with a family history of autoimmunity (40%) had a significantly higher frequency of serum antinucleosome-specific antibodies (83.3%) than patients without such a history (22.2%, P <0.001).

Conclusions

Serum levels of antinucleosome-specific antibodies were increased in some autistic children. However, these data should be treated with caution until further investigations are performed with a larger subject population to determine whether these antibodies have a role in the induction of autoimmunity in a subgroup of autistic children. The role of immunotherapy in children with autism should be also studied.

Redox Regulation and the Autistic Spectrum: Role of Tryptophan Catabolites, Immuno-inflammation, Autoimmunity and the Amygdala

The autistic spectrum disorders (ASD) form a set of multi-faceted disorders with significant genetic, epigenetic and environmental determinants. Oxidative and nitrosative stress (O&NS), immuno-inflammatory pathways, mitochondrial dysfunction and dysregulation of the tryptophan catabolite (TRYCATs) pathway play significant interactive roles in driving the early developmental etiology and course of ASD. O&NS interactions with immuno-inflammatory pathways mediate their effects centrally via the regulation of astrocyte and microglia responses, including regional variations in TRYCATs produced. Here we review the nature of these interactions and propose an early developmental model whereby different ASD genetic susceptibilities interact with environmental and epigenetic processes, resulting in glia biasing the patterning of central interarea interactions. A role for decreased local melatonin and N-acetylserotonin production by immune and glia cells may be a significant treatment target.

Biomarkers in autism

Autism spectrum disorders (ASDs) are complex, heterogeneous disorders caused by an interaction between genetic vulnerability and environmental factors. In an effort to better target the underlying roots of ASD for diagnosis and treatment, efforts to identify reliable biomarkers in genetics, neuroimaging, gene expression, and measures of the body's metabolism are growing. For this article, we review the published studies of potential biomarkers in autism and conclude that while there is increasing promise of finding biomarkers that can help us target treatment, there are none with enough evidence to support routine clinical use unless medical illness is suspected. Promising biomarkers include those for mitochondrial function, oxidative stress, and immune function. Genetic clusters are also suggesting the potential for useful biomarkers.

Camel Milk as a Potential Therapy as an Antioxidant in Autism Spectrum Disorder (ASD)

Extensive studies have demonstrated that oxidative stress plays a vital role in the pathology of several neurological diseases, including autism spectrum disorder (ASD); those studies proposed that GSH and antioxidant enzymes have a pathophysiological role in autism. Furthermore, camel milk has emerged to have potential therapeutic effects in autism. The aim of the current study was to evaluate the effect of camel milk consumption on oxidative stress biomarkers in autistic children, by measuring the plasma levels of glutathione, superoxide dismutase, and myeloperoxidase before and 2 weeks after camel milk consumption, using the ELISA technique. All measured parameters exhibited significant increase after camel milk consumption (P < 0.5). These findings suggest that camel milk could play an important role in decreasing oxidative stress by alteration of antioxidant enzymes and nonenzymatic antioxidant molecules levels, as well as the improvement of autistic behaviour as demonstrated by the improved Childhood Autism Rating Scale (CARS).

Elevated serum levels of macrophage-derived chemokine and thymus and activation-regulated chemokine in autistic children

Background

In some autistic children, there is an imbalance of T helper (Th)1/Th2 lymphocytes toward Th2, which may be responsible for the induction of the production of autoantibodies in these children. Th2 lymphocytes express CCR4 receptors. CCR4 ligands include macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC). They direct trafficking and recruitment of Th2 cells. We are the first to measure serum levels of CCR4 ligands in relation to the degree of the severity of autism.

Methods

Serum concentrations of MDC and TARC were measured, by quantitative sandwich enzyme immunoassay technique, in 56 autistic children and 32 healthy matched children.

Results

Autistic children had significantly higher serum levels of MDC and TARC than healthy controls (P <0.001 and P <0.001, respectively). Children with severe autism had significantly higher serum levels of MDC and TARC than patients with mild to moderate autism (P <0.001 and P = 0.01, respectively). In addition, there were significant positive correlations between CARS and serum levels of both MDC (P <0.001) and TARC (P <0.001) in children with autism. There were significant positive correlations between serum levels of MDC and TARC in autistic children (P <0.001).

Conclusions

Serum levels of CCR4 ligands were elevated in autistic children and they were significantly correlated to the degree of the severity of autism. However, further research is warranted to determine the pathogenic role of CCR4 ligands in autism and to shed light on the therapeutic role of CCR4-ligand antagonism in autistic children.

The link between some alleles on human leukocyte antigen system and autism in children

The reason behind the initiation of autoimmunity to brain in some patients with autism is not well understood. There is an association between some autoimmune disorders and specific alleles of human leukocyte antigen (HLA) system. Thus, we examined the frequency of some HLA-DRB1 alleles in 100 autistic children and 100 healthy matched-children by differential hybridization with sequence-specific oligonucleotide probes. The risk of association between acquisition or absence of these alleles and autism and also a history of autoimmune diseases in autistic relatives was studied. Autistic children had significantly higher frequency of HLA-DRB1*11 allele than controls (P<0.001). In contrast, autistic children had significantly lower frequency of HLA-DRB1*03 allele than controls (P<0.001). Acquisition of HLA-DRB1*011 and absence of HLA-DRB1*3 had significant risk for association with autism (odds ratio: 3.21 and 0.17, respectively; 95% CI: 1.65-6.31 and 0.06-0.45, respectively). HLA-DRB1*11 had a significant risk for association with a family history of autoimmunity in autistic children (odds ratio: 5.67; 95% CI: 2.07-16.3). In conclusions, the link of some HLA alleles to autism and to family history of autoimmunity indicates the possible contributing role of these alleles to autoimmunity in some autistic children. Despite a relatively small sample size, we are the first to report a probable protective association of HLA-DRB1*03 allele with autism. It warrants a replication study of a larger sample to validate the HLA-DRB1 genetic association with autism. This is important to determine whether therapeutic modulations of the immune function are legitimate avenues for novel therapy in selected cases of autism.

Reduced serum concentrations of 25-hydroxy vitamin D in children with autism: relation to autoimmunity

BACKGROUND

Aside from the skeletal health affection, vitamin D deficiency has been implicated as a potential environmental factor triggering for some autoimmune disorders. Vitamin D might play a role in the regulation of the production of auto-antibodies. Immunomodulatory effects of vitamin D may act not only through modulation of T-helper cell function, but also through induction of CD4(+)CD25(high) regulatory T-cells. We are the first to investigate the relationship between serum levels of 25-hydroxy vitamin D and anti-myelin-associated glycoprotein (anti-MAG) auto-antibodies in autistic children.

METHODS

Serum levels of 25-hydroxy vitamin D and anti-MAG auto-antibodies were measured in 50 autistic children, aged between 5 and 12 years, and 30 healthy-matched children. Serum 25-hydroxy vitamin D levels 10-30 ng/mL and < 10 ng/mL were defined as vitamin D insufficiency and deficiency, respectively.

RESULTS

Autistic children had significantly lower serum levels of 25-hydroxy vitamin D than healthy children (P < 0.001) with 40% and 48% being vitamin D deficient and insufficient, respectively. Serum 25-hydroxy vitamin D had significant negative correlations with Childhood Autism Rating Scale (P < 0.001). Increased levels of serum anti-MAG auto-antibodies were found in 70% of autistic patients. Serum 25-hydroxy vitamin D levels had significant negative correlations with serum levels of anti-MAG auto-antibodies (P < 0.001).

CONCLUSIONS

Vitamin D deficiency was found in some autistic children and this deficiency may contribute to the induction of the production of serum anti-MAG auto-antibodies in these children. However, future studies looking at a potential role of vitamin D in the pathophysiology and treatment of autism are warranted.

Elevated serum levels of interleukin-17A in children with autism

BACKGROUND

The T-helper (Th)1/Th2 dichotomy dominated the field of immune regulation until interleukin (IL)-17-expressing T cells (Th17) were proposed to be a third lineage of helper T cells, the key players in the pathogenesis of autoimmune disorders. Autoimmunity to brain tissue may play a pathogenic role in autism. IL-17A is a pro-inflammatory cytokine that has been shown to play an important role in various autoimmune neuroinflammatory diseases. The aim of this study was to measure serum levels of IL-17A in relation to the degree of the severity of autism.

METHODS

Serum IL-17A levels were measured by ELISA in 45 children with autism and 40 matched healthy controls.

RESULTS

Children with autism had significantly higher serum IL-17A levels than healthy controls (P <0.001), with increased serum levels of IL-17A found in 48.9% of the autism group. Patients with severe autism had significantly higher serum IL-17A levels than those with mild to moderate autism (P=0.01), and raised serum IL-17A levels were significantly more common in children with severe autism (67.9%) than in those with mild to moderate autism (17.6%), P=0.001.

CONCLUSIONS

Serum IL-17A levels were raised in the group with autism, and the levels correlated significantly with the severity of autism. This is the first study to measure levels of IL-17A in relation to the severity of autism, to our knowledge. Further research, with a larger subject population, is warranted to determine whether the increase of serum IL-17A levels plasma has a pathogenic role in autism, and whether anti- IL-17A therapy could be useful.