Plasma cytokine levels in children with autistic disorder and unrelated siblings

Gut Microbiota and Autism Spectrum Disorder: A Neuroinflammatory Mediated Mechanism of Pathogenesis?

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social communication and behavior, frequently accompanied by restricted and repetitive patterns of interests or activities. The gut microbiota has been implicated in the etiology of ASD due to its impact on the bidirectional communication pathway known as the gut-brain axis. However, the precise involvement of the gut microbiota in the causation of ASD is unclear. This study critically examines recent evidence to rationalize a probable mechanism in which gut microbiota symbiosis can induce neuroinflammation through intermediator cytokines and metabolites. To develop ASD, loss of the integrity of the intestinal barrier, activation of microglia, and dysregulation of neurotransmitters are caused by neural inflammatory factors. It has emphasized the potential role of neuroinflammatory intermediates linked to gut microbiota alterations in individuals with ASD. Specifically, cytokines like brain-derived neurotrophic factor, calprotectin, eotaxin, and some metabolites and microRNAs have been considered etiological biomarkers. We have also overviewed how probiotic trials may be used as a therapeutic strategy in ASD to reestablish a healthy balance in the gut microbiota. Evidence indicates neuroinflammation induced by dysregulated gut microbiota in ASD, yet there is little clarity based on analysis of the circulating immune profile. It deems the repair of microbiota load would lower inflammatory chaos in the GI tract, correct neuroinflammatory mediators, and modulate the neurotransmitters to attenuate autism. The interaction between the gut and the brain, along with alterations in microbiota and neuroinflammatory biomarkers, serves as a foundational background for understanding the etiology, diagnosis, prognosis, and treatment of autism spectrum disorder.

The Ambiguous Role of Growth Factors in Autism: What Do We Really Know?

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with multifactorial origins, including the potential involvement of neurotrophins and growth factors. These molecules, which are crucial for neuronal survival, synaptic plasticity, and brain development, have been implicated in ASD pathophysiology. Altered levels of neurotrophins such as NGF, BDNF, NT3, and NT4, as well as growth factors like IGF1, VEGF, and FGF, have been associated with cognitive deficits, sensory processing abnormalities, and behavioral issues in ASD patients. However, the literature presents conflicting results, often due to differences in research methodologies, sample sizes, patient populations, and diagnostic criteria. Despite these inconsistencies, the potential of neurotrophins and growth factors as biomarkers and therapeutic targets for ASD remains promising. Future research with standardized methodologies, larger cohorts, and a clearer understanding of genetic influences is needed to further elucidate their roles in ASD diagnosis and treatment.

Toward a better understanding of T cell dysregulation in autism: An integrative review

Autism spectrum disorder (ASD) is a highly heterogeneous disorder characterized by impairments in social, communicative, and restrictive behaviors. Over the past 20 years, research has highlighted the role of the immune system in regulating neurodevelopment and behavior. In ASD, immune abnormalities are frequently observed, such as elevations in pro-inflammatory cytokines, alterations in immune cell frequencies, and dysregulated mechanisms of immune suppression. The adaptive immune system - the branch of the immune system conferring cellular immunity - may be involved in the etiology of ASD. Specifically, dysregulated T cell activity, characterized by altered cellular function and increased cytokine release, presence of inflammatory phenotypes and altered cellular signaling, has been consistently observed in several studies across multiple laboratories and geographic regions. Similarly, mechanisms regulating their activation are also disrupted. T cells at homeostasis coordinate the healthy development of the central nervous system (CNS) during early prenatal and postnatal development, and aid in CNS maintenance into adulthood. Thus, T cell dysregulation may play a role in neurodevelopment and the behavioral and cognitive manifestations observed in ASD. Outside of the CNS, aberrant T cell activity may also be responsible for the increased frequency of immune based conditions in the ASD population, such as allergies, gut inflammation and autoimmunity. In this review, we will discuss the current understanding of T cell biology in ASD and speculate on mechanisms behind their dysregulation. This review also evaluates how aberrant T cell biology affects gastrointestinal issues and behavior in the context of ASD.

Vasostatin-1 restores autistic disorders in an idiopathic autism model (BTBR T+ Itpr3tf/J mice) by decreasing hippocampal neuroinflammation

Chromogranin A (CgA), a ∼ 49 kDa acidic secretory protein, is ubiquitously distributed in endocrine and neuroendocrine cells and neurons. As a propeptide, CgA is proteolytically cleaved to generate several peptides of biological importance, including pancreastatin (PST: hCgA250-301), Vasostatin 1 (VS1: hCgA1-76), and catestatin (CST: CgA 352-372). VS1 represents the most conserved fragment of CgA. A 20 amino acid domain within VS1 (CgA 47-66) exhibits potent antimicrobial and anti-inflammatory activities. Autism is known to be associated with inflammation. Therefore, we seek to test the hypothesis that VS1 modulates autism behaviors by reducing inflammation in the hippocampus. Treatment of C57BL/6 (B6) and BTBR (a mouse model of idiopathic autism) mice with VS1 revealed the following: BTBR mice showed a significant decrease in chamber time in the presence of a stranger or a novel object. Treatment with VS1 significantly increased chamber time in both cases, underscoring a crucial role for VS1 in improving behavioral deficits in BTBR mice. In contrast to chamber time, sniffing time in BTBR mice in the presence of a stranger was less compared to B6 control mice. VS1 did not improve this latter parameter. Surprisingly, sniffing time in BTBR mice in the presence of a novel object was comparable with B6 mice. Proinflammatory cytokines such as IL-6 and IL-1b, as well as other inflammatory markers, were elevated in BTBR mice, which were dramatically reduced after supplementation with VS1. Interestingly, even Beclin-1/p62, pAKT/AKT, and p-p70-S6K/p70-S6K ratios were notably reduced by VS1. We conclude that VS1 plays a crucial role in restoring autistic spectrum disorders (ASD) plausibly by attenuating neuroinflammation.

NLRP3 inflammasome-mitochondrion loop in autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and the presence of restricted interests and repetitive behavior. To date, no single cause has been demonstrated but both genetic and environmental factors are believed to be involved in abnormal brain development. In recent years, immunological and mitochondrial dysfunctions acquired particular interest in the study of the molecular mechanisms underlying the pathophysiology of ASD. For this reason, our study focused on evaluating the mitochondrial component and activation of the NLRP3 inflammasome, a critical player of the innate immune system. The assembly of NLRP3 with ASC mediates activation of Caspase-1, which in turn, by proteolytic cleavage, activates Gasdermin D and the proinflammatory cytokines IL-1β/IL-18 with their subsequent secretion. Using primary fibroblasts of autistic and control patients we studied basal and stimulated conditions. Specifically, LPS and ATP were used to activate the NLRP3 inflammasome and MCC950 for its inhibition. In addition, FCCP was used as a mitochondrial stressor and MitoTEMPO as a scavenger of mitochondrial ROS. Our results showed a hyperactivation of NLRP3 inflammasome in ASDs, as evidenced by the co-localization of the two main components, NLRP3 and ASC, by the higher levels of ASC specks, oligomers and dimers and by the increased amounts of active Caspase-1 and IL-1β. In addition, increased mitochondrial superoxide anion and reduced mitochondrial membrane potential were detected in ASD cells. These data are in accordance with the abnormal mitochondrial morphology evidenced by transmission electron microscopy analysis. Interestingly, NLRP3 inflammasome inhibition with MCC950 improved mitochondrial parameters, while the use of MitoTEMPO, in addition to decrease mitochondrial ROS production, was able to prevent NLRP3 inflammasome activation suggesting for the first time an abnormal bidirectional crosstalk between mitochondria and NLRP3 inflammasome in ASD.

Investigating brain-gut microbiota dynamics and inflammatory processes in an autistic-like rat model using MRI biomarkers during childhood and adolescence

Autism spectrum disorder (ASD) is characterized by social interaction deficits and repetitive behaviors. Recent research has linked that gut dysbiosis may contribute to ASD-like behaviors. However, the exact developmental time point at which gut microbiota alterations affect brain function and behavior in patients with ASD remains unclear. We hypothesized that ASD-related brain microstructural changes and gut dysbiosis induce metabolic dysregulation and proinflammatory responses, which collectively contribute to the social behavioral deficits observed in early childhood. We used an autistic-like rat model that was generated via prenatal valproic acid exposure. We analyzed brain microstructural changes using diffusion tensor imaging (DTI) and examined microbiota, blood, and fecal samples for inflammation biomarkers. The ASD model rats exhibited significant brain microstructural changes in the anterior cingulate cortex, hippocampus, striatum, and thalamus; reduced microbiota diversity (Prevotellaceae and Peptostreptococcaceae); and altered metabolic signatures. The shift in microbiota diversity and density observed at postnatal day (PND) 35, which is a critical developmental period, underscored the importance of early ASD interventions. We identified a unique metabolic signature in the ASD model, with elevated formate and reduced acetate and butyrate levels, indicating a dysregulation in short-chain fatty acid (SCFA) metabolism. Furthermore, increased astrocytic and microglial activation and elevated proinflammatory cytokines-interleukin-1 beta (IL-1β), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α)-were observed, indicating immune dysregulation. This study provided insights into the complex interplay between the brain and the gut, and indicated DTI metrics as potential imaging-based biomarkers in ASD, thus emphasizing the need for early childhood interventions.

Therapeutic efficacy of Genistein in activation of neuronal AC/cAMP/CREB/PKA and mitochondrial ETC-Complex pathways in experimental model of autism: Evidence from CSF, blood plasma and brain analysis

Autism is a complex neurodevelopmental condition characterized by repetitive behaviors, impaired social communication, and various associated conditions such as depression and anxiety. Its multifactorial etiology includes genetic, environmental, dietary, and gastrointestinal contributions. Pathologically, Autism is linked to mitochondrial dysfunction, oxidative stress, neuroinflammation, and neurotransmitter imbalances involving GABA, glutamate, dopamine, and oxytocin. Propionic acid (PRPA) is a short-chain fatty acid produced by gut bacteria, influencing central nervous system functions. Elevated PRPA levels can exacerbate Autism-related symptoms by disrupting metabolic processes and crossing the blood-brain barrier. Our research investigates the neuroprotective potential of Genistein (GNT), an isoflavone compound with known benefits in neuropsychiatric and neurodegenerative disorders, through modulation of the AC/cAMP/CREB/PKA signaling pathway and mitochondrial ETC complex (I-IV) function. In silico analyses revealed GNT's high affinity for these targets. Subsequent in vitro and in vivo experiments using a PRPA-induced rat model of autism demonstrated that GNT (40 and 80 mg/kg., orally) significantly improves locomotion, neuromuscular coordination, and cognitive functions in PRPA-treated rodents. Behavioral assessments showed reduced immobility in the forced swim test, enhanced Morris water maze performance, and restored regular locomotor activity. On a molecular level, GNT restored levels of key signaling molecules (AC, cAMP, CREB, PKA) and mitochondrial complexes (I-V), disrupted by PRPA exposure. Additionally, GNT reduced neuroinflammation and apoptosis, normalized neurotransmitter levels, and improved the complete blood count profile. Histopathological analyses confirmed that GNT ameliorated PRPA-induced brain injuries, restored normal brain morphology, reduced demyelination, and promoted neurogenesis. The study supports GNT's potential in autism treatment by modulating neural pathways, reducing inflammation, and restoring neurotransmitter balance.

The mast cells - Cytokines axis in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disturbance, diagnosed in early childhood. It is associated with varying degrees of dysfunctional communication and social skills, repetitive and stereotypic behaviors. Regardless of the constant increase in the number of diagnosed patients, there are still no established treatment schemes in global practice. Many children with ASD have allergic symptoms, often in the absence of mast cell (MC) positive tests. Activation of MCs may release molecules related to inflammation and neurotoxicity, which contribute to the pathogenesis of ASD. The aim of the present paper is to enrich the current knowledge regarding the relationship between MCs and ASD by providing PPI network analysis-based data that reveal key molecules and immune pathways associated with MCs in the pathogenesis of autism. Network and enrichment analyzes were performed using receptor information and secreted molecules from activated MCs identified in ASD patients. Our analyses revealed cytokines and key marker molecules for MCs degranulation, molecular pathways of key mediators released during cell degranulation, as well as various receptors. Understanding the relationship between ASD and the activation of MCs, as well as the involved molecules and interactions, is important for elucidating the pathogenesis of ASD and developing effective future treatments for autistic patients by discovering new therapeutic target molecules.

Sex-dependent alterations of inflammatory factors, oxidative stress, and histopathology of the brain-gut axis in a VPA-induced autistic-like model of rats

INTRODUCTION

In this study, we aimed to investigate the inflammatory factors, oxidative stress, and histopathological consequences of the brain-gut axis in male and female rats prenatally exposed to VPA.

METHODS

Pregnant Wistar rats were randomly divided into two groups. The animals received saline, and valproic acid (VPA) (600 mg/kg, i.p.) on embryonic day 12.5 (E12.5). All offspring were weaned on postnatal day 21, and the experiments were done in male and female rats on day 60. The brain and intestine tissues were extracted to assess histopathology, inflammation, and oxidative stress.

RESULTS

An increase of interleukin-1β (IL-1β) and interleukin-6 (IL-6) and a decrease of interleukin-10 (IL-10) were observed in the two sexes and two tissues of the autistic rats. In the VPA-exposed animals, malondialdehyde (MDA) and protein carbonyl (PC) increased in the brain of both sexes and the intestines of only the males. The total antioxidant capacity (TAC), superoxide dismutase (SOD), and catalase (CAT) significantly decreased in both tissues of male and female autistic groups. Histopathological evaluation showed that the %apoptosis of the cortex in the autistic male and female groups was more than in controls whereas this parameter in the CA1 and CA3 was significant only in the male rats. In the intestine, histopathologic changes were seen only in the male autistic animals.

CONCLUSION

The inflammatory and antioxidant factors were in line in the brain-gut axis in male and female rats prenatally exposed to VPA. Histopathological consequences were more significant in the VPA-exposed male animals.

Innate Immune Dysfunction and Neuroinflammation in Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by communication and social behavior deficits. The presence of restricted and repetitive behaviors often accompanies these deficits, and these characteristics can range from mild to severe. The past several decades have seen a significant rise in the prevalence of ASD. The etiology of ASD remains unknown; however, genetic and environmental risk factors play a role. Multiple hypotheses converge to suggest that neuroinflammation, or at least the interaction between immune and neural systems, may be involved in the etiology of some ASD cases or groups. Repeated evidence of innate immune dysfunction has been seen in ASD, often associated with worsening behaviors. This evidence includes data from circulating myeloid cells and brain resident macrophages/microglia in both human and animal models. This comprehensive review presents recent findings of innate immune dysfunction in ASD, including aberrant innate cellular function, evidence of neuroinflammation, and microglia activation. Appeared originally in Brain Behav Immun 2023; 108:245-254.

Approaches of marine compounds and relevant immune mediators in Autism Spectrum Disorder: Opportunities and challenges

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that affects social skills, language, communication, and behavioral skills, significantly impacting the individual's quality of life. Recently, numerous works have centered on the connections between the immune and central nervous systems and the influence of neuroinflammation on autism symptomatology. Marine natural products are considered as important alternative sources of different types of compounds, including polysaccharides, polyphenols, sterols, carotenoids, terpenoids and, alkaloids. These compounds present anti-inflammatory, neuroprotective and immunomodulatory activities, exhibiting a potential for the treatment of many diseases. Although many studies address the marine compounds in the modulation of inflammatory mediators, there is a gap regarding their use in the regulation of the immune system in ASD. Thus, this review aims to provide a better understanding regarding cytokines, chemokines, growth factors and immune responses in ASD, as well as the potential of bioactive marine compounds in the immune regulation in ASD. We expect that this review would contribute to the development of therapeutic alternatives for controlling immune mediators and inflammation in ASD.

Discovery of a novel cytokine signature for the diagnosis of autism spectrum disorder in young Arab children in Qatar

Background

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized by impaired social interaction and communication and the occurrence of stereotyped and repetitive behaviors. Several studies have reported altered cytokine profiles in ASD and hence may serve as potential diagnostic biomarkers of the disorder. This study aims to identify diagnostic biomarkers for ASD in a well-defined study cohort in Qatar.

Methods

We measured the protein levels of 45 cytokines in the plasma samples of age- and gender-matched children (2-4 years) with ASD (n = 100) and controls (n = 60) using a Luminex multiplex assay. We compared the differences in the levels of these cytokines between the two study groups and then fitted the significantly altered cytokines into a logistic regression model to examine their diagnostic potential for ASD.

Results

We found elevated levels of IFN-γ, FGF-2, IL-1RA, and IL-13 and reduced levels of eotaxin, HGF, IL-1 alpha, IL-22, IL-9, MCP-1, SCF, SDF-1 alpha, VEGFA, and IP-10 in the plasma of children with ASD compared to controls. Furthermore, we observed that elevated levels of IFN-γ (odds ratio (OR) = 1.823; 95% (confidence interval) CI = 1.206, 2.755; p = 0.004) and FGF-2 (OR = 2.528; 95% CI = 1.457, 4.385; p < 0.001) were significantly associated with increased odds of ASD, whereas reduced levels of eotaxin (OR = 0.350; 95% CI = 0.160, 0.765; p = 0.008) and HGF (OR = 0.220; 95% CI = 0.070, 0.696; p = 0.010) were significantly associated with lower odds of ASD relative to controls. The combination of these four cytokines revealed an area under the curve (ROC-AUC) of 0.829 (95% CI = 0.767, 0.891; p < 0.001), which demonstrates the diagnostic accuracy of the four-cytokine signature.

Conclusions

Our results identified a panel of cytokines that could discriminate between children with ASD and controls in Qatar. In addition, our findings support the predominance of a Th1 immune phenotype in ASD children and emphasize the need to validate these results in larger populations.

Cadmium exposure exacerbates immunological abnormalities in a BTBR T+ Itpr3tf/J autistic mouse model by upregulating inflammatory mediators in CD45R-expressing cells

Autism spectrum disorder (ASD) is a neurodevelopmental illness characterized by behavior, learning, communication, and social interaction abnormalities in various situations. Individuals with impairments usually exhibit restricted and repetitive actions. The actual cause of ASD is yet unknown. It is believed, however, that a mix of genetic and environmental factors may play a role in its development. Certain metals have been linked to the development of neurological diseases, and the prevalence of ASD has shown a positive association with industrialization. Cadmium chloride (Cd) is a neurotoxic chemical linked to cognitive impairment, tremors, and neurodegenerative diseases. The BTBR T+ Itpr3tf/J (BTBR) inbred mice are generally used as a model for ASD and display a range of autistic phenotypes. We looked at how Cd exposure affected the signaling of inflammatory mediators in CD45R-expressing cells in the BTBR mouse model of ASD. In this study, we looked at how Cd affected the expression of numerous markers in the spleen, including IFN-γ, IL-6, NF-κB p65, GM-CSF, iNOS, MCP-1, and Notch1. Furthermore, we investigated the effect of Cd exposure on the expression levels of numerous mRNA molecules in brain tissue, including IFN-γ, IL-6, NF-κB p65, GM-CSF, iNOS, MCP-1, and Notch1. The RT-PCR technique was used for this analysis. Cd exposure increased the number of CD45R+IFN-γ+, CD45R+IL-6+, CD45R+NF-κB p65+, CD45R+GM-CSF+, CD45R+GM-CSF+, CD45R+iNOS+, and CD45R+Notch1+ cells in the spleen of BTBR mice. Cd treatment also enhanced mRNA expression in brain tissue for IFN-γ, IL-6, NF-κB, GM-CSF, iNOS, MCP-1, and Notch1. In general, Cd increases the signaling of inflammatory mediators in BTBR mice. This study is the first to show that Cd exposure causes immune function dysregulation in the BTBR ASD mouse model. As a result, our study supports the role of Cd exposure in the development of ASD.

Plasma cytokine concentrations of children with autism spectrum disorder and neurotypical siblings

Several studies of autism spectrum disorder (ASD) have shown cytokine dysregulation in children with ASD, leading to a consideration of the immune theory of the ASD etiopathogenesis and a debate about cytokines as potential biomarkers of ASD. However, the results of these studies are still inconsistent. Overall, studies comparing the cytokine levels of children with ASD and neurotypical siblings achieved relatively different results than studies with control groups of non-siblings. The studies suggest that the immune profile of siblings of individuals with ASD serving as control is more similar to children with ASD than the profile of non-siblings. However, there are still only a few studies with control groups including neurotypical siblings of children with ASD. The aim of our study was to determine whether the concentration of plasma cytokine levels may differentiate children with ASD from their neurotypical siblings. The sample consisted of 40 children with ASD (mean age 7.11 years, SD 2.9) and 21 neurotypical siblings (mean age 7.38, SD 3.3). Levels of 20 cytokines were included into the statistical analysis. A multiple logistic regression model using multiple corrections showed that an increase in log-transformed plasma G-CSF (granulocyte colony stimulating factor) concentration is associated with an increased risk of the child being diagnosed as an ASD case (OR = 4.35, 95% CI 1.77, 10.73). Although the significantly increased concentration of G-CSF suggests a slightly different activity of the immune system of children with ASD, the overall cytokine profile of their siblings appeared to be very similar.

IL-6, homocysteine, and autism spectrum phenotypes: an investigation among adults with autism spectrum disorder and their first-degree relatives

BACKGROUND

The importance of recognizing different kinds of autism spectrum presentations among adults, including subthreshold forms and the broad autism phenotype (BAP), has been increasingly highlighted in recent studies. Meanwhile, the possible involvement of immune system deregulation and altered methylation/trans-sulfuration processes in autism spectrum disorder (ASD) is gaining growing attention, but studies in this field are mainly focused on children. In this framework, the aim of this study was to compare plasmatic concentrations of IL-6 and homocysteine (HCY) among adults with ASD, their first-degree relatives, and healthy controls (CTLs), investigating also possible correlations with specific autism symptoms.

METHODS

Plasma concentrations of IL-6 and HCY were measured in a group of adult subjects with ASD, their first-degree relatives (BAP group), and healthy controls (CTL). All participants were also evaluated with psychometric instruments.

RESULTS

IL-6 and HCY concentrations were significantly higher in the ASD group than in CTLs, while BAP subjects reported intermediate results. Significant correlations were reported between biochemical parameters and psychometric scales, particularly for the dimension of ruminative thinking.

CONCLUSIONS

These findings support the hypothesis of a key involvement of HCY-related metabolism and immune system alteration in autism spectrum pathophysiology. HCY and IL-6 seem to show different associations with specific autism dimensions.

Innate immune dysfunction and neuroinflammation in autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by communication and social behavior deficits. The presence of restricted and repetitive behaviors often accompanies these deficits, and these characteristics can range from mild to severe. The past several decades have seen a significant rise in the prevalence of ASD. The etiology of ASD remains unknown; however, genetic and environmental risk factors play a role. Multiple hypotheses converge to suggest that neuroinflammation, or at least the interaction between immune and neural systems, may be involved in the etiology of some ASD cases or groups. Repeated evidence of innate immune dysfunction has been seen in ASD, often associated with worsening behaviors. This evidence includes data from circulating myeloid cells and brain resident macrophages/microglia in both human and animal models. This comprehensive review presents recent findings of innate immune dysfunction in ASD, including aberrant innate cellular function, evidence of neuroinflammation, and microglia activation.

Effects of COVID-19 on children with autism

The coronavirus disease 2019 (COVID-19) pandemic affects all countries and populations worldwide, significantly impacting people with autism with a high risk of morbidity and mortality due to COVID-19. Approximately 25% of children with autism have an asymptomatic or symptomatic immune deficiency or dysfunction. In addition, they frequently have various comorbid conditions that increase the severity of COVID-19. In addition, severe COVID-19 during pregnancy may increase the risk of autism in the offspring. Furthermore, severe acute respiratory syndrome coronavirus 2 could target human nervous system tissues due to its neurotrophic effects. The COVID-19 pandemic intensely impacts many patients and families in the autism community, especially the complex management of autism-associated disorders during the complete lockdown. During the complete lockdown, children with autism had difficulties coping with the change in their routine, lack of access to special education services, limited physical space available, and problems related to food and sleep. Additionally, children with autism or intellectual disabilities are more liable to be abused by others during the pandemic when the standard community supports are no longer functioning to protect them. Early detection and vaccination of children with autism against COVID-19 are highly indicated. They should be prioritized for testing, vaccination, and proper management of COVID-19 and other infectious diseases. In this review, we discuss the various effects of COVID-19 on children with autism, the difficulties they face, the increased risk of infection during pregnancy, how to alleviate the impact of COVID-19, and how to correct the inequalities in children with autism.

In search of immune cellular sources of abnormal cytokines in the blood in autism spectrum disorder: A systematic review of case-control studies

Abnormal cytokine levels in circulating blood have been repeatedly reported in autism; however, the underlying cause remains unclear. This systematic review aimed to investigate cytokine levels in peripheral blood compartments and identify their potential immune cellular sources in subjects with autism through comparison with controls. We conducted an electronic database search (PubMed, Scopus, ProQuest Central, Ovid, SAGE Journals, and Wiley Online Library) from inception (no time limits) to July 9, 2020, and identified 75 relevant articles. Our qualitative data synthesis focused on results consistently described in at least three independent studies, and we reported the results according to the PRISMA protocol. We found that compared with controls, in subjects with autism, cytokines IL-6, IL-17, TNF-α, and IL-1β increased in the plasma and serum. We also identified monocytes, neutrophils, and CD4+ T cells as potential sources of these elevated cytokines in autism. Cytokines IFN-γ, TGF-β, RANTES, and IL-8 were increased in the plasma/serum of subjects with autism, and IFN-γ was likely produced by CD4+ T cells and natural killer (NK) cells, although conflicting evidence is present for IFN-γ and TGF-β. Other cytokines-IL-13, IL-10, IL-5, and IL-4-were found to be unaltered in the plasma/serum and post-stimulated blood immune cells in autistic individuals as compared with controls. The frequencies of T cells, monocytes, B cells, and NK cells were unchanged in subjects with autism as opposed to controls, suggesting that abnormal cytokines were unlikely due to altered cell numbers but might be due to altered functioning of these cells in autism. Our results support existing studies of abnormal cytokines in autism and provide comprehensive evidence of potential cellular sources of these altered cytokines in the context of autism.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020205224, identifier [CRD42020205224].

Immune Dysregulation in Autism Spectrum Disorder: What Do We Know about It?

Autism spectrum disorder (ASD) is a group of complex multifactorial neurodevelopmental disorders characterized by a wide and variable set of neuropsychiatric symptoms, including deficits in social communication, narrow and restricted interests, and repetitive behavior. The immune hypothesis is considered to be a major factor contributing to autism pathogenesis, as well as a way to explain the differences of the clinical phenotypes and comorbidities influencing disease course and severity. Evidence highlights a link between immune dysfunction and behavioral traits in autism from several types of evidence found in both cerebrospinal fluid and peripheral blood and their utility to identify autistic subgroups with specific immunophenotypes; underlying behavioral symptoms are also shown. This review summarizes current insights into immune dysfunction in ASD, with particular reference to the impact of immunological factors related to the maternal influence of autism development; comorbidities influencing autism disease course and severity; and others factors with particular relevance, including obesity. Finally, we described main elements of similarities between immunopathology overlapping neurodevelopmental and neurodegenerative disorders, taking as examples autism and Parkinson Disease, respectively.

Increased Monocyte Production of IL-6 after Toll-like Receptor Activation in Children with Autism Spectrum Disorder (ASD) Is Associated with Repetitive and Restricted Behaviors

The prevalence of autism spectrum disorder (ASD) has starkly increased, instigating research into risk factors for ASD. This research has identified immune risk factors for ASD, along with evidence of immune dysfunction and excess inflammation frequently experienced by autistic individuals. Increased innate inflammatory cytokines, including interleukin (IL)-6, are seen repeatedly in ASD; however, the origin of excess IL-6 in ASD has not been identified. Here we explore specific responses of circulating monocytes from autistic children. We isolated CD14⁺ monocytes from whole blood and stimulated them for 24 h under three conditions: media alone, lipoteichoic acid to activate TLR2, and lipopolysaccharide to activate TLR4. We then measured secreted cytokine concentrations in cellular supernatant using a human multiplex bead immunoassay. We found that after TLR4 activation, CD14⁺ monocytes from autistic children produce increased IL-6 compared to monocytes from children with typical development. IL-6 concentration also correlated with worsening restrictive and repetitive behaviors. These findings suggest dysfunctional activation of myeloid cells, and may indicate that other cells of this lineage, including macrophages, and microglia in the brain, might have a similar dysfunction. Further research on myeloid cells in ASD is warranted.

Cytokines profile in neonatal and adult wild-type mice post-injection of U. S. pediatric vaccination schedule

Introduction

A recent study from our laboratory demonstrated a number of neurobehavioral abnormalities in mice colony injected with a mouse-weight equivalent dose of all vaccines that are administered to infants in their first 18 months of life according to the U. S. pediatric vaccination schedule.

Cytokines have been studied extensively as blood immune and inflammatory biomarkers, and their association with neurodevelopmental disorders. Given the importance of cytokines in early neurodevelopment, we aimed to investigate the potential post-administration effects of the U. S. pediatric vaccines on circulatory cytokines in a mouse model.

In the current study, cytokines have been assayed at early and late time points in mice vaccinated early in postnatal life and compared with placebo controls.

Materials and methods

Newborn mouse pups were divided into three groups: i) vaccine (V1), ii) vaccine ​× ​3 (V3) and iii) placebo control. V1 group was injected with mouse weight-equivalent of the current U. S. pediatric vaccine schedule. V3 group was injected with same vaccines but at triple the dose and the placebo control was injected with saline. Pups were also divided according to the sampling age into two main groups: acute- and chronic-phase group. Blood samples were collected at postnatal day (PND) 23, two days following vaccine schedule for the acute-phase group or at 67 weeks post-vaccination for the chronic-phase groups. Fifteen cytokines were analyzed: GM-CSF, IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-12p70, IL-13, IL-17A, MCP-1, TNF-α, and VEGF-A. Wilcoxon Rank Sum test or unpaired Student's t-test was performed where applicable.

Results

IL-5 levels in plasma were significantly elevated in the V1 and V3 group compared with the control only in the acute-phase group. The elevation of IL-5 levels in the two vaccine groups were significant irrespective of whether the sexes were combined or analyzed separately. Other cytokines (VEGF-A, TNF-α, IL-10, MCP-1, GM-CSF, IL-6, and IL-13) were also impacted, although to a lesser extent and in a sex-dependent manner. In the acute-phase group, females showed a significant increase in IL-10 and MCP-1 levels and a decrease in VEGF-A levels in both V1 and V3 group compared to controls. In the acute-phase, a significant increase in MCP-1 levels in V3 group and CM-CSF levels in V1 and V3 group and decrease in TNF-α levels in V1 group were observed in treated males as compared with controls. In chronic-phase females, levels of VEGF-A in V1 and V3 group, TNF-α in V3 group, and IL-13 in V1 group were significantly decreased in contrast with controls. In chronic-phase males, TNF-α levels were significantly increased in V1 group and IL-6 levels decreased in V3 group in comparison to controls. The changes in levels of most tested cytokines were altered between the early and the late postnatal assays.

Conclusions

IL-5 levels significantly increased in the acute-phase of the treatment in the plasma of both sexes that were subjected to V1 and V3 injections. These increases had diminished by the second test assayed at week 67. These results suggest that a profound, albeit transient, effect on cytokine levels may be induced by the whole vaccine administration supporting our recently published observations regarding the behavioral abnormalities in the same mice. These observations support the view that the administration of whole pediatric vaccines in a neonatal period may impact at least short-term CNS functions in mice.

Association of Peripheral Blood Levels of Cytokines With Autism Spectrum Disorder: A Meta-Analysis

Background: Although increasing evidence suggests an association between alterations in peripheral cytokines and autism spectrum disorder (ASD), a consensus is lacking. To determine whether abnormal cytokine profiles in peripheral blood were associated with ASD, we performed this systemic review and meta-analysis. Methods: A systematic literature search was conducted through the Embase, PubMed, Web of Knowledge, PsycINFO, and Cochrane databases up to 4 June 2020. Clinical studies exploring the aberration of peripheral cytokines of autistic patients and controls were included in our meta-analysis. We pooled extracted data using fixed- or random-effects models based on heterogeneity tests with Comprehensive Meta-analysis software. We converted standardized mean differences to Hedges' g statistic to obtain the effect sizes adjusted for sample size. Subgroup analyses, sensitivity analyses, meta-regression, and publication bias tests were also carried out. Results: Sixty-one articles (326 studies) were included to assess the association between 76 cytokines and ASD. We conducted our meta-analysis based on 37 cytokines with 289 studies. Since there were fewer than three studies on any of the other 39 cytokines, we only provided basic information for them. The levels of peripheral IL-6, IL-1β, IL-12p70, macrophage migration inhibitory factor (MIF), eotaxin-1, monocyte chemotactic protein-1 (MCP-1), IL-8, IL-7, IL-2, IL-12, tumor necrosis factor-α (TNF-α), IL-17, and IL-4 were defined as abnormal cytokines in the peripheral blood of ASD patients compared with controls. The other 24 cytokines did not obviously change in ASD patients compared with the controls. Conclusions: The findings of our meta-analysis strengthen the evidence for an abnormal cytokine profile in ASD. These abnormal cytokines may be potential biomarkers for the diagnosis and treatment of ASD in the future.

Polymorphism of interleukin-1β and interleukin-1 receptor antagonist genes in children with autism spectrum disorders

In this study, we first investigated interleukin-1 beta (IL-1β) and IL-1 receptor antagonist (IL-1RA) levels in a cohort of Egyptian children with autism spectrum disorder (ASD) and in healthy controls. Second, we examined the single-nucleotide polymorphisms (SNPs) at positions -31 and - 511 of the IL-1β gene promoter and IL1RA and assessed the association between IL1B and IL1RA polymorphisms with ASD. We examined IL1β promoter polymorphism at -511 (IL-1β-511) and - 31 (IL-1β-31) and IL1RA gene polymorphism in 80 children with ASD and 60 healthy children. The children with ASD had significantly higher levels of IL-1β and IL-1RA than the controls. The children with ASD also had significantly higher frequencies of homozygous (CC) and heterozygous (TC) genotype variants of IL-1β-511, and IL-1RA than the controls. Moreover, the frequency of the IL-1β-511 allele (C) was higher in the ASD group than in the controls (p = .001). The homozygous and heterozygous variants of IL-1RA allele II were also significantly higher in the ASD group than in the control group. There was no significant association between the IL-1β-31 genotype and autism classes. However, there were significant differences in the distribution of the IL-1RA heterogeneous genotype and allele II among children with severe autism. The inflammatory role of cytokines has been implicated in a variety of neuropsychiatric pathologies, including autism. Our data show alterations in the IL-1β system, with abnormally increased serum levels of IL-1β and IL-1RA in the children with ASD. Further, polymorphisms in the IL-1β-511 and IL-1RA genotype variants correlated positively with autism severity and behavioral abnormalities. IL-1β-511 and IL-1RA gene polymorphisms could impact ASD risk and may be used as potential biomarkers of ASD. Variations in the IL-1β and IL-1RA systems may have a role in the pathophysiology of ASD.

Autism spectrum disorders and natural killer cells: a review on pathogenesis and treatment

Introduction: Autism spectrum disorder (ASD), as a wide spectrum of neurodevelopmental disorders, is characterized by early-onset impairments in social-communication, repetitive behaviors, and restrictive interests.Areas covered: Although still unknown, there are some pieces of evidence suggesting altered immune function in the etiology of ASD. This review aims to summarize studies linking Natural Killer (NK) cells to ASD by searching through databases like MEDLINE and Scopus up to October 2020. NK cells play important roles in the innate immune system and immune regulation. As parts of the immune system, they interact with the neural system as well. Immune dysregulations such as autoimmunity and improper immune responses to both internal and external stimulations, especially in early developmental stages of the brain, may induce neurodevelopmental disorders. NK cells' dysfunction in children with ASD as well as their parents have been highlighted in many studies.Expert opinion: Changes in the frequency, gene expressions, cytotoxicity features, and receptors of NK cells are reported in children with ASD. Immune therapy for children with ASD with immune abnormality has shown promising results. However, further studies are needed to elucidate the exact role of NK cells in the pathogenesis of ASD providing future treatment options for these children.

Microbiota, Immune System and Autism Spectrum Disorders: An Integrative Model towards Novel Treatment Options

BACKGROUND

Autism Spectrum Disorder (ASD) is a condition strongly associated with genetic predisposition and familial aggregation. Among ASD patients, different levels of symptoms severity are detectable, while the presence of intermediate autism phenotypes in close relatives of ASD probands is also known in literature. Recently, increasing attention has been paid to environmental factors that might play a role in modulating the relationship between genomic risk and development and severity of ASD. Within this framework, an increasing body of evidence has stressed a possible role of both gut microbiota and inflammation in the pathophysiology of neurodevelopment. The aim of this paper is to review findings about the link between microbiota dysbiosis, inflammation and ASD.

METHODS

Articles ranging from 1990 to 2018 were identified on PUBMED and Google Scholar databases, with keyword combinations as: microbiota, immune system, inflammation, ASD, autism, broad autism phenotype, adult.

RESULTS

Recent evidence suggests that microbiota alterations, immune system and neurodevelopment may be deeply intertwined, shaping each other during early life. However, results from both animal models and human samples are still heterogeneous, while few studies focused on adult patients and ASD intermediate phenotypes.

CONCLUSION

A better understanding of these pathways, within an integrative framework between central and peripheral systems, might not only shed more light on neural basis of ASD symptoms, clarifying brain pathophysiology, but it may also allow to develop new therapeutic strategies for these disorders, still poorly responsive to available treatments.

Salivary Cytokine Profile as a Possible Predictor of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is characterized by neurodevelopmental disorders and alterations in immune function and cytokine levels. The aim of this study is to determine the salivary levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), Regulated on Activation, Normal T-cell Expressed and Secreted (RANTES), and Eotaxin in children with ASD and in healthy controlsto assess their predictive potential. We explored correlations between the cytokine levels and the neurodevelopmental disorders related to ASD. The study comprised 19 children with ASD and 19 typically developing (TD) ones. We analyzed salivary levels of IL-1β, IL-6, IL-8, TNFα, MCP-1, RANTES, and eotaxin on Luminex with custom-designed 7-plex kits. The level of RANTES in ASD children was significantly lower than those of TD. In TDs, the salivary levels of IL-1β, MCP-1, and TNFα correlated positively with age. In ASD, the cytokine levels did not correlate with age. There were statistically significant differences between the RANTES level and aggression and gait disturbances, between IL-8 level and fixations/stimulations, and between IL-1β level and no active speech. The levels of the cytokine detected can manifest both systemic and local changes related to ASD. The cytokine pattern cannot be used as a sole ASD predictor, but the salivary levels may be helpful in categorizing the ASD subtype.

Therapeutic Effects of the In Vitro Cultured Human Gut Microbiota as Transplants on Altering Gut Microbiota and Improving Symptoms Associated with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a brain-based neurodevelopmental disorder characterized by behavioral abnormalities. Accumulating studies show that the gut microbiota plays a vital role in the pathogenesis of ASD, and gut microbiota transplantation (GMT) is a promising technique for the treatment of ASD. In clinical applications of GMT, it is challenging to obtain effective transplants because of the high costs of donor selection and heterogeneity of donors' gut microbiota, which can cause different clinical responses. In vitro batch culture is a fast, easy-to-operate, and repeatable method to culture gut microbiota. Thus, the present study investigates the feasibility of treating ASD with in vitro cultured gut microbiota as transplants. We cultured gut microbiota via the in vitro batch culture method and performed GMT in the maternal immune activation (MIA)-induced ASD mouse model with original donor microbiota and in vitro cultured microbiota. Open field, three-chamber social, marble burying, and self-grooming tests were used for behavioral improvement assessment. Serum levels of chemokines were detected. Microbial total DNA was extracted from mouse fecal samples, and 16S rDNA was sequenced using Illumina. Our results showed that GMT treatment with original and cultured donor gut microbiota significantly ameliorated anxiety-like and repetitive behaviors and improved serum levels of chemokines including GRO-α (CXCL1), MIP-1α (CCL3), MCP-3 (CCL7), RANTES (CCL5), and Eotaxin (CCL11) in ASD mice. Meanwhile, the gut microbial communities of the two groups that received GMT treatment were changed compared with the ASD mice groups. In the group treated with in vitro cultured donor gut microbiota, there was a significant decrease in the relative abundance of key differential taxa, including S24-7, Clostridiaceae, Prevotella_other, and Candidatus Arthromitus. The relative abundance of these taxa reached close to the level of healthy mice. Prevotella_other also decreased in the group treated with original donor gut microbiota, with a significant increase in Ruminococcaceae and Oscillospira. The present study demonstrated that GMT with in vitro cultured microbiota also improved behavioral abnormalities and chemokine disorders in an ASD mouse model compared with GMT with original donor gut microbiota. In addition, it significantly modified several key differential taxa in gut microbial composition.

Differential regulation of Nrf2 is linked to elevated inflammation and nitrative stress in monocytes of children with autism

Autism spectrum disorder (ASD) is a very complex neurodevelopmental disorder characterized by deficits in social and communication skills. Innate immune cells like monocytes are believed to play a cardinal role in neuroimmune inflammation and nitrative stress. On the other hand, Nrf2, a basic leucine zipper transcription factor plays a significant role in protecting the immune cells against inflammation and oxidants. However, its role in monocytes of ASD children and typically developing control (TDC) children has not been elucidated in relation with inflammation and nitrative stress. Therefore, this study was undertaken to evaluate Nrf2 expression/activity along with parameters of inflammation (NFkB, IL-6, IL-1β) and nitrative stress (iNOS, nitrotyrosine) in monocytes of ASD/TDC children. Further, sulforaphane (SFN) was utilized as an Nrf2 activator to assess its effect on above said inflammatory and nitrative stress parameters. Our study shows that monocytes of ASD subjects have decreased Nrf2 expression/activity along with increased inflammation and nitrative stress. Further, monocytes from ASD have deficiency in induction of Nrf2 activity upon stimulation with LPS. However, activation of Nrf2 in vitro by SFN reverses LPS-induced effects on inflammation in monocytes by reduction in NFkB signaling. Further, treatment with SFN also reverses LPS-induced effects on nitrative stress (iNOS, nitrotyrosine) in monocytes of ASD subjects. This study propounds the idea that SFN protects against nitrative stress and inflammation by downregulating oxidative stress and inflammation through blockade of NFkB signaling in autistic children. This may be the reason behind reported ameliorative effects of SFN in ASD subjects.

T cell populations in children with autism spectrum disorder and co-morbid gastrointestinal symptoms

Children with ASD are more likely to experience gastrointestinal (GI) symptoms than typically-developed children. Numerous studies have reported immune abnormalities and inflammatory profiles in the majority of individuals with ASD. Immune dysfunction is often hypothesized as a driving factor in many GI diseases and it has been suggested that it is more apparent in children with ASD that exhibit GI symptoms. In this study we sought to characterize peripheral T cell subsets in children with and without GI symptoms, compared to healthy typically-developing children. Peripheral blood mononuclear cells were isolated from participants, who were categorized into three groups: children with ASD who experience GI symptoms (n ​= ​14), children with ASD who do not experience GI symptoms (n ​= ​10) and typically-developing children who do not experience GI symptoms (n ​= ​15). In order to be included in the GI group, GI symptoms such as diarrhea, constipation, and/or pain while defecating, had to be present in the child regularly for the past 6 months; likewise, in order to be placed in the no GI groups, bowel movements could not include the above symptoms present throughout development. Cells were assessed for surface markers and intracellular cytokines to identify T cell populations. Children with ASD and GI symptoms displayed elevated TH17 populations (0.757% ​± ​0.313% compared to 0.297% ​± ​0.197), while children with ASD who did not experience GI symptoms showed increased frequency of TH2 populations (2.02% ​± ​1.08% compared to 1.01% ​± ​0.58%). Both ASD groups showed evidence of reduced gut homing regulatory T cell populations compared to typically developing children (ASDGI:1.93% ​± ​0.75% and ASDNoGI:1.85% ​± ​0.89 compared to 2.93% ​± ​1.16%). Children with ASD may have deficits in immune regulation that lead to differential inflammatory T cell subsets that could be linked to associated co-morbidities.

Immune network dysregulation associated with child neurodevelopmental delay: modulatory role of prenatal alcohol exposure

Background

Evidence suggests that cytokine imbalances may be at the root of deficits that occur in numerous neurodevelopmental disorders, including schizophrenia and autism spectrum disorder. Notably, while clinical studies have demonstrated maternal cytokine imbalances with alcohol consumption during pregnancy—and data from animal models have identified immune disturbances in alcohol-exposed offspring—to date, immune alterations in alcohol-exposed children have not been explored. Thus, here we hypothesized that perturbations in the immune environment as a result of prenatal alcohol exposure will program the developing immune system, and result in immune dysfunction into childhood. Due to the important role of cytokines in brain development/function, we further hypothesized that child immune profiles might be associated with their neurodevelopmental status.

Methods

As part of a longitudinal study in Ukraine, children of mothers reporting low/no alcohol consumption or moderate-to-heavy alcohol consumption during pregnancy were enrolled in the study and received neurodevelopmental assessments. Group stratification was based on maternal alcohol consumption and child neurodevelopmental status resulting in the following groups: A/TD, alcohol-consuming mother, typically developing child; A/ND, alcohol-consuming mother, neurodevelopmental delay in the child; C/TD, control mother (low/no alcohol consumption), typically development child; and C/ND, control mother, neurodevelopmental delay in the child. Forty cytokines/chemokines were measured in plasma and data were analyzed using regression and constrained principle component analysis.

Results

Analyses revealed differential cytokine network activity associated with both prenatal alcohol exposure and neurodevelopmental status. Specifically, alcohol-exposed children showed activation of a cytokine network including eotaxin-3, eotaxin, and bFGF, irrespective of neurodevelopmental status. However, another cytokine network was differentially activated based on neurodevelopmental outcome: A/TD showed activation of MIP-1β, MDC, and MCP-4, and inhibition of CRP and PlGF, with opposing pattern of activation/inhibition detected in the A/ND group. By contrast, in the absence of alcohol-exposure, activation of a network including IL-2, TNF-β, IL-10, and IL-15 was associated with neurodevelopmental delay.

Conclusions

Taken together, this comprehensive assessment of immune markers allowed for the identification of unique immune milieus that are associated with alcohol exposure as well as both alcohol-related and alcohol-independent neurodevelopmental delay. These findings are a critical step towards establishing unique immune biomarkers for alcohol-related and alcohol-independent neurodevelopmental delay.

A meta-analysis of pro-inflammatory cytokines in autism spectrum disorders: Effects of age, gender, and latitude

BACKGROUND

Autism spectrum disorders (ASD) occur in 1.5% of the general population worldwide. Studies suggest that ASD might have more costs than diabetes and attention deficit and hyperactivity disorder by 2025. Dysregulation of the cytokine system is well-documented in ASD. We conducted a meta-analysis of studies providing data on circulating concentrations of pro-inflammatory cytokines in people with ASD compared with control subjects without ASD.

METHODS

We identified potentially eligible studies by systematically searching electronic databases from inception to February 2018.

RESULTS

Thirty-eight studies with total of 2487 participants (1393 patients with ASD and 1094 control subjects) were included in the meta-analysis; 13 for interferon (IFN)-γ, 17 for interleukin (IL)-1β, 22 for IL-6, 19 for tumor necrosis factor (TNF)-α, 4 for IL-1α, 6 for IL-2, 4 for IL-7, 8 for IL-8, 14 for IL-12, 3 for IL-15, 12 for IL-17, 3 for IL-18, 3 for IL-2 receptor, 3 for TNF-β, and 3 for IL-23. We found medium increases in levels of plasma IFN-γ (standardized mean difference, SMD = 0.53) and serum IL-1β (SMD = 0.56) and small increases in levels of blood IL-1β (SMD = 0.35), serum IL-6 (SMD = 0.30) and serum TNF-α (SMD = 0.31) for patients with ASD. Meta-regression analyses identified latitude as a negative moderator of the effect size (ES) of difference in mean levels of IFN-γ (R² = 0.26) and TNF-α (R² = 0.74). Also, difference in the mean age between patients and controls had a negative interaction with the ES of difference in mean levels of IL-1β. In contrast, there was a positive effect of the moderator of difference in the proportion of male subjects between patients and controls on the ES of difference in mean levels of IL-1β. We found no significant alterations in peripheral levels of other pro-inflammatory cytokines including IL-1α, IL-2, IL-2R, IL-3, IL-7, IL-8, IL-12, IL-12p40, IL-12p70, IL-15, IL-17, IL-18, IL-23, TBF-β, and TNFRI/II in patients with ASD.

CONCLUSIONS

This meta-analysis provides evidence for higher concentration of pro-inflammatory cytokines IFN-γ, IL-1β, IL-6, and TNF-α in autistic patents compared with control subjects. Also, meta-regression analyses point to the interaction of latitude, age, and gender with peripheral alterations of associated pro-inflammatory cytokines.

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.

Anti-inflammatory cytokines in autism spectrum disorders: A systematic review and meta-analysis

BACKGROUND

In the search for the causes of autism spectrum disorders (ASD), inflammatory markers have emerged as potential candidates. The present meta-analysis was performed on studies examining circulating concentrations of anti-inflammatory cytokines in people with ASD compared with control subjects without ASD.

METHODS

We identified potentially eligible studies by systematically searching electronic databases from inception to February 2018.

RESULTS

Twenty-five studies with a total of 1754 participants (1022 patients with ASD and 732 control subjects) were included in the mate-analysis; 4 for interferon (IFN)-α, 9 for interleukin (IL)-1 receptor antagonist (Ra), 9 for IL-4, 6 for IL-5, 3 for IL-9, 14 for IL-10, 7 for IL-13, and 6 for transforming growth factor (TGF)-β. We found a moderate decrease in plasma levels of IL-10 (SMD = -0.59) and a small decrease in serum levels of IL-1Ra (SMD = -0.25) in patients with ASD. On the contrary, serum IL-5 levels were slightly increased (SMD = 0.26) in these patients. We conducted meta-regression analyses to investigate the possible effect of moderatos on the effect size (ES) of difference in mean levels of IL-10. Difference in the mean age between patients and controls showed a negative influence on the ES and was able to explain about 0.4 of total between-study variance. In contrast, latitude exerted a positive effect on the ES and explained a lower proportion (0.1) of total between-study variance.

CONCLUSIONS

This meta-analysis provides evidence for the lower concentration of anti-inflammatory cytokines IL-10 and IL-1Ra in autistic patients compared with control subjects. Also, meta-regression analyses point to the interaction of latitude, age, and gender with peripheral alterations of associated anti-inflammatory cytokines.

Ginseng oligopeptides protect against irradiation-induced immune dysfunction and intestinal injury

Intestinal injury and immune dysfunction are commonly encountered after irradiation therapy. While the curative abilities of ginseng root have been reported in prior studies, there is little known regarding its role in immunoregulation of intestinal repairability in cancer patients treated with irradiation. Our current study aims to closely examine the protective effects of ginseng-derived small molecule oligopeptides (Panax ginseng C. A. Mey.) (GOP) against irradiation-induced immune dysfunction and subsequent intestinal injury, using in vitro and in vivo models. Expectedly, irradiation treatment resulted in increased intestinal permeability along with mucosal injury in both Caco-2 cells and mice, probably due to disruption of the intestinal epithelial barrier, leading to high plasma lipopolysaccharide (LPS) and pro-inflammatory cytokines levels. However, when the cells were treated with GOP, this led to diminished concentration of plasma LPS and cytokines (IL-1 and TNF-α), suggesting its dampening effect on inflammatory and oxidative stress, and potential role in restoring normal baseline intestinal permeability. Moreover, the Caco-2 cells treated with GOP showed high trans-epithelial electrical resistance (TEER) and low FITC-dextran paracellular permeability when compared to the control group. This could be explained by the higher levels of tight junction proteins (ZO-1 and Occludin) expression along with reduced expression of the apoptosis-related proteins (Bax and Caspase-3) noticed in the GOP-treated cells, highlighting its role in preserving intestinal permeability, through prevention of their degradation while maintaining normal levels of expression. Further confirmatory in vivo data showed that GOP-treated mice exhibited high concentrations of lymphocytes (CD3+, CD4+, CD8+) in the intestine, to rescue the irradiation-induced damage and restore baseline intestinal integrity. Therefore, we propose that GOP can be used as an adjuvant therapy to attenuate irradiation-induced immune dysfunction and intestinal injury in cancer patients.

Immune Abnormalities in Autism Spectrum Disorder-Could They Hold Promise for Causative Treatment?

Autism spectrum disorders (ASD) are characterized by impairments in language and communication development, social behavior, and the occurrence of stereotypic patterns of behavior and interests. Despite substantial speculation about causes of ASD, its exact etiology remains unknown. Recent studies highlight a link between immune dysfunction and behavioral traits. Various immune anomalies, including humoral and cellular immunity along with abnormalities at the molecular level, have been reported. There is evidence of altered immune function both in cerebrospinal fluid and peripheral blood. Several studies hypothesize a role for neuroinflammation in ASD and are supported by brain tissue and cerebrospinal fluid analysis, as well as evidence of microglial activation. It has been shown that immune abnormalities occur in a substantial number of individuals with ASD. Identifying subgroups with immune system dysregulation and linking specific cellular immunophenotypes to different symptoms would be key to defining a group of patients with immune abnormalities as a major etiology underlying behavioral symptoms. These determinations would provide the opportunity to investigate causative treatments for a defined patient group that may specifically benefit from such an approach. This review summarizes recent insights into immune system dysfunction in individuals with ASD and discusses the potential implications for future therapies.

A pilot study of high-dose intravenous immunoglobulin 5% for autism: Impact on autism spectrum and markers of neuroinflammation

Research has shown that a subset of the autism spectrum disorder (ASD) population presents with immune dysregulation. To explore this topic further, we investigated the efficacy and tolerability of intravenous immunoglobulin (IVIG) infusion in children with ASD. In this study, participants were recruited based on a diagnosis of autistic disorder, Asperger's disorder, or pervasive developmental disorder not otherwise specified. Participants also showed evidence of immune dysfunction based on abnormal levels of specific biomarkers, including CD40 ligand (CD154), lymphocyte stimulation, and T or B cell dysfunction. Of 17 screened patients, 14 completed the trial and received IVIG treatment (1 g/kg dose) for ten 21-day treatment cycles. The primary endpoint was disease improvement assessed using standardized cognitive and behavioral tests (Children's Communication Checklist [CCC-2], Social Responsiveness Scale [SRS], Aberrant Behavior Checklist [ABC], Clinical Global Impressions-Severity [CGI-S] and -Improvement [CGI-I], Autism Diagnostic Observation Schedule [ADOS], and Peabody Picture Vocabulary Test [PPVT]). Secondary endpoints included experimental biomarkers such as CD154, toll-like receptor-4, memory B cells, FOXP3, and lymphocyte stimulation. Significant improvements from baseline to study endpoint were observed in several subscales of the CCC-2, SRS, CGI-I, CGI-S, and ADOS, including Associated Maladaptive Behaviors (P ≤ .043), Reciprocal Social Interaction (P = .015), Communication (P < .001), and Stereotyped Behaviors and Repetitive Interests (P ≤ .013). Statistically significant reductions were also seen in numerous secondary outcomes of immunological biomarkers indicative of neuroinflammation. IVIG was well tolerated; no subjects withdrew due to an adverse event, and clinical data showed no evidence of thromboembolic events. Autism Res 2018, 11: 421-433. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY

Since research has demonstrated a link between autism spectrum disorder (ASD) and immune dysfunction, this study investigated the efficacy and tolerability of intravenous immunoglobulin (IVIG) infusion in children with ASD. Fourteen patients received IVIG treatment and were assessed using standardized cognitive and behavioral tests. Following treatment with IVIG, significant improvement was observed across several subscales of the clinical tests and significant reductions were seen in the markers of neuroinflammation. These data suggest that inflammatory etiologies may play a role in select cases of autism, and IVIG treatment may exert a positive impact on behaviors and markers of inflammation in ASD.

Inflammatory dysregulation of monocytes in pediatric patients with obsessive-compulsive disorder

BACKGROUND

Although the exact etiology of obsessive-compulsive disorder (OCD) is unknown, there is growing evidence of a role for immune dysregulation in the pathophysiology of the disease, especially in the innate immune system including the microglia. To test this hypothesis, we studied inflammatory markers in monocytes from pediatric patients with OCD and from healthy controls.

METHODS

We determined the percentages of total monocytes, CD16+ monocytes, and classical (CD14^highCD16-), intermediate (CD14^highCD16^low), and non-classical (CD14^lowCD16^high) monocyte subsets in 102 patients with early-onset OCD and in 47 healthy controls. Moreover, proinflammatory cytokine production (GM-CSF, IL-1β, IL-6, IL-8, and TNF-α) was measured by multiplex Luminex analysis in isolated monocyte cultures, in basal conditions, after exposure to lipopolysaccharide (LPS) to stimulate immune response or after exposure to LPS and the immunosuppressant dexamethasone.

RESULTS

OCD patients had significantly higher percentages of total monocytes and CD16+ monocytes than healthy controls, mainly due to an increase in the intermediate subset but also in the non-classical monocytes. Monocytes from OCD patients released higher amounts of GM-CSF, IL-1β, IL-6, IL-8, and TNF-α than healthy controls after exposure to LPS. However, there were no significant differences in basal cytokine production or the sensitivity of monocytes to dexamethasone treatment between both groups. Based on monocyte subset distribution and cytokine production after LPS stimulation, patients receiving psychoactive medications seem to have an intermediate inflammatory profile, that is, lower than non-medicated OCD individuals and higher than healthy controls.

CONCLUSIONS

These results strongly support the involvement of an enhanced proinflammatory innate immune response in the etiopathogenesis of early-onset OCD.

Cytokine levels and associations with symptom severity in male and female children with autism spectrum disorder

Background

Autism spectrum disorders (ASDs) are complex, pervasive, and heterogeneous neurodevelopmental conditions with varying trajectories, significant male bias and largely unknown etiology. However, an understanding of the biological mechanisms driving pathophysiology is evolving. Immune system aberrations, as identified through cytokine profiles, are believed to have a role in ASD. Altered cytokine levels may facilitate identification of ASD subtypes as well as provide biological markers of response to effective treatments. Research exploring the relationship between cytokine profiles and ASD symptoms is, however, in its infancy. The objective of this study was to explore relationships between cytokine levels and the severity of ASD and other clinical traits.

Methods

Multiplex assay techniques were used to measure levels of 27 cytokines in plasma samples from a cohort of 144 children diagnosed with ASD.

Results

Overall, results showed a significant negative association between platelet-derived growth factor (PDGF)-BB, and the severity of ASD symptoms. Furthermore, a significant interaction with sex suggested a different immune profile for females compared to males. ASD symptom severity was negatively associated with levels of 4 cytokines, IL-1β, IL-8, MIP-1β, and VEGF, in females, but not in males.

Conclusions

Results of the present study suggest that an altered cytokine response or profile is associated with the severity of ASD-related symptoms, with sex a potential modifier of this relationship. Further research in larger populations which recognizes the importance of sex comparisons and longitudinal assessments are now required to extend and further describe the role of the immune system in ASD.

Electronic supplementary material

The online version of this article (10.1186/s13229-017-0176-2) contains supplementary material, which is available to authorized users.

Deficiency of a brain-specific chemokine-like molecule, SAM3, induces cardinal phenotypes of autism spectrum disorders in mice

Chemokines are small secreted signaling proteins produced by a broad range of cells, including immune cells. Several studies have recently suggested potential roles of chemokines and their receptors in the pathophysiology of autism spectrum disorders (ASDs). SAM3 is a novel brain-specific chemokine-like molecule with an unknown physiological function. We explored the relevance of chemokines in the development of ASD in mice, with a focus on SAM3. We generated Sam3 gene knockout (KO) mice and characterized their behavioral phenotypes, with a focus on those relevant to ASD. Sam3-deficient mice displayed all three core phenotypes of ASD: impaired responses to social novelty, defects in social communication, and increased repetitive behavior. In addition, they showed increased anxiety. Interestingly, gender differences were identified for several behaviors: only male Sam3 KO mice exhibited increased anxiety and increased repetitive behaviors. Sam3 KO mice did not exhibit changes in other behaviors, including locomotor activities, fear learning and memory, and object recognition memory. These findings indicate that a deficiency of SAM3, a novel brain-specific chemokine-like molecule, may lead to the pathogenesis of ASDs and suggest the possibility that SAM3, a soluble factor, could be a novel therapeutic target for ASD treatment.

Neuroinflammation in Autism Spectrum Disorders: Role of High Mobility Group Box 1 Protein

The pathogenesis of autism spectrum disorder (ASD) likely involves genetic and environmental factors, impacting the complex neurodevelopmental and behavioral abnormalities of the disorder. Scientific research studies emerging within the past two decades suggest that immune dysfunction and inflammation have pathogenic influences through different mechanisms, all leading to both a chronic state of low grade inflammation, and alterations in the central nervous system and immune response, respectively. The high mobility group box-1 protein (HMGB1) is an inflammatory marker which has been shown to play a role in inducing and influencing neuroinflammation. Current evidences suggest a possible role in the multiple pathogenic mechanisms of ASD. The aim of this manuscript is to review the major hypothesis for ASD pathogenesis, with specific regards to the immunological ones, and to provide a comprehensive review of the current data about the association between HMGB1 and ASD. A systematic search has been carried out through Medline via Pubmed to identify all original articles published in English, on the basis of the following keywords: "HMGB1", "autism", "autism spectrum disorder", "neuroinflammation", and "child".

High monocyte level and low lymphocyte to monocyte ratio in autism spectrum disorders

Objective: This study aims to investigate the level of peripheral blood mononuclear cells and their ratios which may point to the immunological mechanisms involved in the etiopathogenesis of ASD. Method: The complete blood count parameters of the 45 ASD cases were compared with those of healthy controls.Childhood Autism Rating Scale (CARS) was performed to measure the disease severity. Results: The monocytes of ASD group were significantly higher; and the lymphocyte-to-monocyte ratio (LMR) was lower than the controls'. LMR and neutrophil-to-lymphocyte ratio were found to be predictors of ASD. The decrease in LMR (B: -0.744; P=0.035; CI: -1.431 to -0.056) and the increase in age (B: 0.432; P=0.045; CI: 0.011-0.853) were related to high CARS scores in linear regression analyses. Conclusions: The results of this study support the role of altered immune cell counts and ratios in ASD. A high monocyte level and low LMR may have diagnostic values in autism.

Ginseng (Panax ginseng Meyer) oligopeptides regulate innate and adaptive immune responses in mice via increased macrophage phagocytosis capacity, NK cell activity and Th cells secretion

Traditionally used as a restorative medicine, ginseng (Panax ginseng Meyer) has been the most widely used and acclaimed herb in Chinese communities for thousands of years. To investigate the immune-modulating activity of ginseng oligopeptides (GOP), 420 healthy female BALB/c mice were intragastrically administered distilled water (control), whey protein (0.15 g per kg body weight (BW)), and GOP 0.0375, 0.075, 0.15, 0.3 and 0.6 g per kg BW for 30 days. Blood samples from mice were collected from the ophthalmic venous plexus and then sacrificed by cervical dislocation. Seven assays were conducted to determine the immunomodulatory effects of GOP on innate and adaptive immune responses, followed by flow cytometry to investigate spleen T lymphocyte sub-populations, multiplex sandwich immunoassays to investigate serum cytokine and immunoglobulin levels, and ELISA to investigate intestinally secreted immunoglobulin to study the mechanism of GOP affecting the immune system. Our results showed that GOP was able to enhance innate and adaptive immune responses in mice by improving cell-mediated and humoral immunity, macrophage phagocytosis capacity and NK cell activity. Notably, the use of GOP revealed a better immune-modulating activity compared to whey protein. We conclude that the immune-modulating activity might be due to the increased macrophage phagocytosis capacity and NK cell activity, and the enhancement of T and Th cells, as well as IL-2, IL-6 and IL-12 secretion and IgA, IgG1 and IgG2b production. These results indicate that GOP could be considered a good candidate that may improve immune functions if used as a dietary supplement, with a dosage that ranges from 0.3 to 0.6 g per kg BW.

Serum and cerebrospinal fluid immune mediators in children with autistic disorder: a longitudinal study

BACKGROUND

The causes of autism likely involve genetic and environmental factors that influence neurobiological changes and the neurological and behavioral features of the disorder. Immune factors and inflammation are hypothesized pathogenic influences, but have not been examined longitudinally.

METHODS

In a cohort of 104 participants with autism, we performed an assessment of immune mediators such as cytokines, chemokines, or growth factors in serum and cerebrospinal fluid (n = 67) to determine potential influences of such mediators in autism.

RESULTS

As compared with 54 typically developing controls, we found no evidence of differences in the blood profile of immune mediators supportive of active systemic inflammation mechanisms in participants with autism. Some modulators of immune function (e.g., EGF and soluble CD40 ligand) were increased in the autism group; however, no evidence of group differences in traditional markers of active inflammation (e.g., IL-6, TNFα, IL-1β) were observed in the serum. Further, within-subject stability (measured by estimated intraclass correlations) of most analytes was low, indicating that a single measurement is not a reliable prospective indicator of concentration for most analytes. Additionally, in participants with autism, there was little correspondence between the blood and CSF profiles of cytokines, chemokines, and growth factors, suggesting that peripheral markers may not optimally reflect the immune status of the central nervous system. Although the relatively high fraction of intrathecal production of selected chemokines involved in monocyte/microglia function may suggest a possible relationship with the homeostatic role of microglia, control data are needed for further interpretation of its relevance in autism.

CONCLUSIONS

These longitudinal observations fail to provide support for the hypothesized role of disturbances in the expression of circulating cytokines and chemokines as an indicator of systemic inflammation in autism. ClinicalTrials.gov, NCT00298246.

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).

Altered plasma levels of chemokines in autism and their association with social behaviors

Autism Spectrum Disorder (ASD) is a group of neurodevelopment disorders with an unclear etiology. Chemokines have been implicated in the etiology and pathogenesis of ASD. The current study investigated the plasma levels of seven chemokines (RANTES, Eotaxin, MIP-1 α, MIP-1 β, MCP-1, IP-10, and MIG) in 42 young autistic patients and 35 age-matched typically developing (TD) children. The study also tested the association between these chemokine levels and social behaviors, as measured by the Social Responsiveness Scale (SRS). Compared to the TD children, RANTES, MIP-1α, and MIP-1β were higher, while IP-10 and MIG were lower in the autistic patients, after correcting for multiple comparisons. Among these seven chemokines, MIP-1α, MIP-1β and IP-10 levels were found to be associated with social behaviors in all the participants. Moreover, MIP-1α and IP-10 were found to be independent predictors of social behaviors. The results of our study support the hypothesis that altered chemokine levels are involved in the pathophysiology of ASD and they indicate that chemokines plasma levels could be potential biomarkers for ASD.

Characterization of immune cell phenotypes in adults with autism spectrum disorders

Autism spectrum disorders (ASDs) are neurodevelopmental disorders characterized by impairments in verbal and non-verbal communication, impaired social interactions and repetitive behaviors. There is evidence of a link between ASD symptoms and immune dysfunction, but few studies have been performed in adult patients to confirm this. In this work, we used flow cytometry to study immunological differences in peripheral blood mononuclear cells from 59 adult patients and 26 healthy control subjects to identify possible immune cell profiles related with this group of disorders. We analyzed six immune cell subpopulations (ie, B-cells, CD4(+) and CD8(+) T-cells, NK, NKT cells, and monocytes) and their corresponding stages of apoptosis and activation. The most noteworthy results showed that, compared to healthy controls, patients had increased percentages of CD8(+) T-cells and B-cells, and a decrease in the percentage of NKT cells. Regarding CD25 expression, we found overall CD25(+) overexpression, primarily in NK and NKT cells. Apoptosis percentage showed an increasing trend only in monocytes of patients. These data support a link between ASD and immune dysfunction, suggesting that specific cellular phenotypes and/or activation status of immune cells may be relevant in adult ASD.

Multiplex Immunoassay of Plasma Cytokine Levels in Men with Alcoholism and the Relationship to Psychiatric Assessments

Chronic alcohol use alters adaptive immunity and cytokine activity influencing immunological and hormone responses, inflammation, and wound healing. Brain cytokine disturbances may impact neurological function, mood, cognition and traits related to alcoholism including impulsiveness. We examined the relationship between plasma cytokine levels and self-rated psychiatric symptoms in 40 adult males (mean age 51 ± 6 years; range 33–58 years) with current alcohol dependence and 30 control males (mean age 48 ± 6 years; range 40–58 years) with no history of alcoholism using multiplex sandwich immunoassays with the Luminex magnetic-bead based platform. Log-transformed cytokine levels were analyzed for their relationship with the Symptom Checklist-90R (SCL-90R), Barratt Impulsivity Scales (BIS) and Alcoholism Severity Scale (ASS). Inflammatory cytokines (interferon γ-induced protein-10 (IP-10); monocyte chemoattractant protein-1 (MCP1); regulated on activation, normal T cell expressed and secreted (RANTES)) were significantly elevated in alcoholism compared to controls while bone marrow-derived hematopoietic cytokines and chemokines (granulocyte-colony stimulating factor (GCSF); soluble CD40 ligand (sCD40L); growth-related oncogene (GRO)) were significantly reduced. GRO and RANTES levels were positively correlated with BIS scales; and macrophage-derived chemokine (MDC) levels were positively correlated with SCL-90R scale scores (p < 0.05). Elevated inflammatory mediators in alcoholism may influence brain function leading to increased impulsiveness and/or phobia. The novel association between RANTES and GRO and impulsivity phenotype in alcoholism should be further investigated in alcoholism and psychiatric conditions with core impulsivity and anxiety phenotypes lending support for therapeutic intervention.

Elevated plasma oxytocin levels in children with Prader-Willi syndrome compared with healthy unrelated siblings

Prader-Willi syndrome (PWS) is a rare genetic disorder associated with distinct abnormal behaviors including hyperphagia, profound social deficits, and obsessive-compulsive tendencies. PWS males showed reduced oxytocin receptor (OTR) gene expression and density in the hypothalamic paraventricular nucleus that may play a role in PWS psychopathology. Oxytocin is an anorexigenic neuropeptide similar to vasopressin that is associated with social cognition and obsessive-compulsive behavior. To evaluate oxytocin biology in PWS, we examined overnight fasting plasma oxytocin levels in 23 children with PWS (mean ± SD age: 8.2 ± 2.0 year) having genetic confirmation and 18 age matched healthy unrelated siblings without PWS (mean ± SD age: 8.2 ± 2.3 year) and a similar gender ratio under the same clinical assessments, specimen processing and laboratory conditions. Multiplex immune assays were carried out using the Milliplex Human Neuropeptide Magnetic panel and the Luminex system. Natural log-transformed oxytocin levels were analyzed using general linear model adjusting for diagnosis, gender, age and body mass index (BMI). Oxytocin plasma levels were significantly elevated in children with PWS (168 ± 121 pg/ml) compared with unrelated and unaffected siblings without the diagnosis of PWS (64.8 ± 83.8 pg/ml, F = 8.8, P < 0.01) and the diagnosis of PWS predicted oxytocin level (F = 9.5, P < 0.003) in controlled regression analysis with an overall model fit R(2) = 0.33 (P < 0.01). The symptoms of hyperphagia, anxiety and repetitive behaviors classically seen in PWS may be related to the disruption of oxytocin responsivity or feedback in the hypothalamic paraventricular nucleus possibly influencing vasopressin signaling. Further study is needed to characterize oxytocin function in PWS.

EVALUATION OF PLASMA SUBSTANCE P AND BETA-ENDORPHIN LEVELS IN CHILDREN WITH PRADER-WILLI SYNDROME

BACKGROUND

Prader-Willi syndrome (PWS) is a rare obesity-related genetic disorder often caused by a deletion of the chromosome 15q11-q13 region inherited from the father or by maternal disomy 15. Growth hormone deficiency with short stature, hypogonadism, cognitive and behavioral problems, analgesia, decreased gastric motility and decreased ability to vomit with hyperphagia are common in PWS leading to severe obesity in early childhood, if not controlled. Substance P (SP) and beta-endorphin (BE) are neuropeptides involved with centrally and peripherally mediated pain perception, emotional regulation, and gastric motility impacting nausea, emesis and feeding patterns.

OBJECTIVE

The goal of this study was to investigate potential mechanisms for PWS symptom development for pain, emotion and gastric motility and plasma levels of substance P and beta-endorphin between PWS and unrelated unaffected children.

METHODOLOGY

Plasma samples were collected from 23 Caucasian children with PWS and 18 unrelated, unaffected siblings with an average age of 8.2 ±2.0 years and age range of 5 to 11 years following an overnight fast and neuropeptide substance p and beta-endorphin levels were assessed using Multiplex sandwich immunoassays using the Luminex magnetic-bead based platform. Linear regression analysis was carried out on log-transformed values adjusted for age, sex, and body mass index (BMI).

RESULTS

The mean plasma SP (57 ± 23 pg/ml) and BE (592 ± 200 pg/ml) levels in PWS were significantly higher than SP (35 ± 20 pg/ml, F=10.5, P<0.01) and BE (402 ± 162 pg/ml, F=10.8, P<0.01) levels found in unrelated, unaffected siblings suggesting a previously uncharacterized neuroendocrine pathophysiology in PWS.

CONCLUSIONS

The increased BE and SP plasma levels relative to unrelated, unaffected siblings may contribute to hyperphagia, abnormal pain sensation and adrenal insufficiency seen in PWS. Increases in SP levels may be modulated by central and/or peripheral actions of BE on opioid, GABA or POMC precursors and may reflect loss of feedback inhibitory control. Further studies are needed to confirm and elucidate the biochemical basis for observed disturbances in neuropeptide levels seen in our study and may impact on the development and persistence of symptoms commonly seen in PWS.

Potential cytokine biomarkers in autism spectrum disorders

Autism spectrum disorders (ASD) are complex neurodevelopmental disorders characterized by impairments in three core behavioral areas. As prevalence rates for ASD continue to rise there is also increasing interest in finding biomarkers associated with ASD. The use of biomarkers could help identify those at risk for ASD or ASD-associated comorbid conditions and help to predict the developmental course of these children. Due to the heterogeneity of ASD, biomarkers may help to identify subpopulations within ASD that share similar traits or profiles. Such work could lead to specialized therapy and help to develop biomarkers whereby the benefits of treatments/therapies for individuals could be monitored over time and through clinical trials. Over the last 10 years, the evidence of immune involvement in ASD has been steadily growing and many investigators have begun to look at possible immune biomarkers, such as immune cytokine profiles, in children with ASD.