Cytokine aberrations in autism spectrum disorder: a systematic review and meta-analysis

Regional skull translocator protein elevation in autistic adults detected by PET-MRI

Immune processes have been implicated in the pathophysiology of autism spectrum disorder (ASD). Brain borders, such as the skull, have recently been highlighted as sites where neuro-immune interactions occur with key consequences for brain immunity. Translocator protein (TSPO), a mitochondrial protein involved in immune functions, was measured in the skull using [11C]PBR28 positron emission tomography-magnetic resonance imaging (PET-MRI) in 38 autistic adults (26 males, 12 females) and 29 age-and sex-matched healthy controls (19 males, 10 females). [11C]PBR28 uptake relative to a pseudo-reference region assessed using standardized uptake value ratio (SUVR) revealed elevated TSPO in autistic adults in frontal and temporal skull. We did not observe an association between [11C]PBR28 uptake in total or regional skull areas and autism symptom severity. C-reactive protein levels were positively associated with [11C]PBR28 uptake in the total skull across participants. Lastly, [11C]PBR28 uptake in the total skull was stable across a 4-month period. This work indicates regional TSPO elevations in the skull in autistic adults, which may suggest immune involvement.

Profiling of activated monocyte populations in autism and associations with increased severity and comorbid behaviors

Immune dysfunction in autism spectrum disorder (ASD) has been widely reported and is associated with increased impairments in social interactions, communication, repetitive behaviors, anxiety and gastrointestinal problems. Several lines of evidence point towards increased activation of the innate immune system including activation of microglia, increases in innate inflammatory cytokines/chemokines in blood, brain tissue and CSF, activated dendritic cells and macrophages, and abnormal peripheral monocyte cell function. Monocytes are major players in innate immunity and have important functions in the phagocytosis of pathogens or debris, immune defense and cytokine/chemokine production. However, little is known about the frequencies of different circulating monocytes populations in ASD compared with similarly aged typically developing (TD) controls. In this study, the profile of circulating monocytes exhibiting different markers of activation were assessed in 77 children with ASD, and 49 TD controls who were enrolled as part of the Autism Phenome Project and were of a similar age, 2-4 years old. The frequencies of monocytes expressing the activation marker CD137 (4-1BB) were significantly increased in children with ASD and associated with greater behavioral impairments. In addition, although the frequencies of non-classical monocytes (CD14+CD16+) were not significantly different across groups, they were linked to worse behaviors in both the context of ASD and TD. Conversely classical monocytes were associated with better behavioral outcomes. These data further implicate monocytes and innate immune cells in the complex pathophysiology of ASD. Monocyte cells play key roles in modulating immune responses and differences in the activation profiles of these cells may result in immune dysfunction in children with ASD.

Available Treatments for Autism Spectrum Disorder: From Old Strategies to New Options

Autism spectrum disorder (ASD) is a condition that is gaining increasing interest in research and clinical fields. Due to the improvement of screening programs and diagnostic procedures, an increasing number of cases are reaching clinical attention. Despite this, the available pharmacological options for treating ASD-related symptoms are still very limited, and while a wide number of studies are focused on children or adolescents, there is a need to increase research about the treatment of ASD in adult subjects. Given this framework, this work aims to review the available literature about pharmacological treatments for ASD, from older strategies to possible new therapeutic targets for this condition, which are often poorly responsive to available resources. The literature, besides confirming the efficacy of the approved drugs for ASD, shows a lack of adequate research for several psychopharmacological treatments despite possible promising results that need to be further investigated.

Novel Inflammatory Biomarkers for Autism Spectrum Disorder Detected by Plasma Olink Proteomics

Background: Research evidence has recently shown an association between autism spectrum disorder (ASD) and inflammation. For example, the expression of inflammatory cytokines is abnormal in children with ASD, and maternal inflammation can lead to ASD-like behavior in offspring. These studies suggest that inflammation plays an important role in the occurrence and development of ASD. Inflammatory cytokines may, therefore, be potential biomarkers for ASD. In the present study, we sought to systematically identify inflammatory biomarkers of children with ASD. Methods: We used Olink proteomics to comprehensively examine differentially expressed inflammation-related proteins in 60 children with ASD and 28 children with typical development (TD). We validated our findings using published data. Results: A total of 18 inflammation-related proteins were differentially expressed between the ASD and TD groups. Compared with the TD group, the expression of all differentially expressed proteins was up-regulated in the ASD group. Furthermore, eight differentially expressed proteins showed good diagnostic efficacy, as delineated by area under the curve (AUC) values of > 0.7. To our knowledge, this is the first time that up-regulated interleukin-17C (IL-17C), chemokine ligand (CCL)-19, and CCL20 have been detected in the plasma of children with ASD (with AUC of 0.839, 0.763, and 0.756, respectively). We also found that there was a negative correlation between inflammatory cytokines and SRS scores. Conclusions: Multiple inflammatory markers were increased in children with ASD. IL-17C, CCL19, and CCL20 exhibit potential as biomarker candidates for ASD. Elevated expression levels of cytokines may enhance social ability in ASD.

The Role of Oxidative Stress in Autism Spectrum Disorder Pathophysiology, Diagnosis and Treatment

Autism spectrum disorder (ASD) is a significant health problem with no known single cause. There is a vast number of evidence to suggest that oxidative stress plays an important role in this disorder. The author of this article reviewed the current literature in order to summarise the knowledge on the subject. In this paper, the role of oxidative stress is investigated in the context of its influence on pathogenesis, the use of oxidative stress biomarkers as diagnostic tools and the use of antioxidants in ASD treatment. Given the heterogeneity of ASD aetiology and inadequate treatment approaches, the search for common metabolic traits is essential to find more efficient diagnostic tools and treatment methods. There are increasing data to suggest that oxidative stress is involved in the pathogenesis of ASD, both directly and through its interplay with inflammation and mitochondrial dysfunction. Oxidative stress biomarkers appear to have good potential to be used as diagnostic tools to aid early diagnosis of ASD. The results are most promising for glutathione and its derivatives and also for isoprostanses. Probably, complex dedicated multi-parametric metabolic panels may be used in the future. Antioxidants show good potential in ASD-supportive treatment. In all described fields, the data support the importance of oxidative stress but also a need for further research, especially in the context of sample size and, preferably, with a multicentre approach.

Tetrahydrobiopterin and Autism Spectrum Disorder: A Systematic Review of a Promising Therapeutic Pathway

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by persistent deficits in social communication and interaction, along with restricted and repetitive patterns of behavior, interests, or activities. ASD encompasses a wide spectrum of clinical presentations and functional impairments, ranging from mild to severe. Despite its prevalence, the underlying physiopathological mechanisms of ASD remain largely unknown, resulting in a lack of effective targeted therapeutic interventions, contributing to significant financial and emotional burdens on affected families and the healthcare system. Emerging evidence suggests that dysfunction in the tetrahydrobiopterin (BH4) pathway may impair the activity of monoaminergic and nitric oxide (NO)-dependent neurons in individuals with ASD. To explore this potential mechanism, we conducted a systematic review to analyze such impairments to gather information on whether the off-label use of BH4 could represent a novel pharmacological approach for managing ASD. Following the PRISMA 2020 guidelines, we systematically reviewed the literature from four databases: PubMed, Virtual Health Library, Cochrane Library, and SciELO, from January 1967 to December 2021. The quality of the included studies was assessed using the Newcastle-Ottawa scale. The inclusion criteria for this systematic review focused on identifying articles published in English that contained the following keywords, used in various combinations: autism, ASD, autism spectrum disorder, BH4, tetrahydrobiopterin, neopterin, NO, nitric oxide. The analysis was performed between December 2020 and December 2021. The collected data demonstrated that BH4 metabolism was altered in individuals with ASD. Lower levels of BH4 were reported in biological samples from ASD-affected individuals compared to age- and sex-matched controls. Additionally, neopterin levels were elevated in plasma and urine, but decreased in cerebrospinal fluid, while nitric oxide levels were consistently reported to be higher across studies. Treatment with BH4 has shown potential in improving ASD-related symptoms. The reported increase in neopterin in biological fluids indicates inflammation, while the reduction in BH4 levels suggests a potential shift in its metabolic role. Specifically, BH4 may be diverted from its primary role in neurotransmitter synthesis to function as an antioxidant or to perpetuate inflammation through NO production. Given that BH4 is a critical cofactor in monoaminergic neurotransmission, its dysfunction highlights the molecule's therapeutic potential. BH4, already FDA-approved for other conditions, emerges as a promising off-label candidate to alleviate ASD symptomatology.

Palmitoylethanolamide supplementation for human health: A state-of-the-art systematic review of Randomized Controlled Trials in patient populations

Interest in preventative dietary interventions for human health has increasingly focused on the endocannabinoid (eCB)-like compound palmitoylethanolamide (PEA), a bioactive lipid mediator with anti-inflammatory, analgesic, and neuroprotective properties. This Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020-compliant systematic review aimed at collecting and comprehensively discussing all available data from Randomized Controlled Trials (RCTs) evaluating the efficacy and tolerability of PEA supplementation across human illnesses in patient populations. Overall, 48 eligible outputs from 47 RCTs were extracted, covering neuropsychiatric (n = 15), neurological (n = 17), somatic (n = 13), and visceral (n = 11) disturbances, as well as PEA effects on blood/plasma or other tissue biomarkers (n = 10). The strongest evidence emerged from RCTs exploring PEA impact on pain management and measures of general wellbeing, especially in its ultramicronized/micronized or cold-water dispersible formulations, showing good tolerability compared to controls. Also, alongside symptom improvement, PEA demonstrated to modulate biomarkers early altered in the initial phases of an illness or contributing to its progression, suggesting a disease-modifying potential. This systematic review provided a comprehensive overview of the therapeutic potential of PEA across RCTs, highlighting its versatility either as monotherapy or add-on treatment for various clinical conditions.

Adipose tissue may not be a major player in the inflammatory pathogenesis of Autism Spectrum Disorder

Purpose

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder increasingly recognized for its strong association with chronic inflammation. Adipose tissue functions as an endocrine organ and can secrete inflammatory cytokines to mediate inflammation. However, its involvement in ASD-related inflammation remains unclear. The present study aimed to clarify the role of adipose tissue in inducing inflammatory responses associated with ASD.

Methods

A total of 36 children with ASD and 18 unrelated healthy controls, aged 2-14.5 years, were enrolled in the study. The up-regulated differentially expressed genes from the GSE18123 dataset were subjected to gene ontology (GO) enrichment analysis to explore ASD-associated pathways. Plasma cytokines and adipokines levels were quantified using Milliplex MAP immunoaffinity technology. The BTBR T + Itprtf/J (BTBR) mice that are known for their core ASD behavioral traits and inflammatory phenotypes were employed as an animal ASD model to verify the key clinical findings.

Results

GO enrichment analyses revealed immune dysfunction in ASD. Symptom analysis showed that the recruited individuals had typical autistic symptoms. Plasma analysis showed no significant difference in adipokines levels, including adiponectin, leptin, resistin, adipsin, and lipocalin-2, between the ASD and control groups. However, markedly elevated levels of IL-6, IL-8, and tumor necrosis factor (TNF-α) were detected in children with ASD, suggesting that the inflammatory state is independent of adipokines. Similar results were also observed in BTBR autistic mice. Notably, levels of insulin, which are closely related to the exertion of adipokines function, also showed no significant changes.

Conclusions

Our findings suggest that inflammation in ASD likely originates from non-adipocyte sources, implying that adipose tissue may not play a major role in inflammatory pathogenesis of ASD. Consequently, targeting adipose-related inflammation may not be an effective treatment approach, providing new directions for the development of targeted interventions.

tVNS alters inflammatory response in adult VPA-induced mouse model of autism: evidence for sexual dimorphism

Autism is a neurodevelopmental disorder with limited treatment alternatives and which incidence is increasing. Some research suggests that vagus nerve simulation might lead to the reduction of certain symptom. Therefore, we aimed to examine the effect of bilateral transcutaneous auricular vagus nerve stimulation (tVNS) on the inflammatory response in an adult valproic acid (VPA) induced mouse (C57BL6) model of autism for the first time. The autism model was induced by oral VPA administration (600 mg·kg-1) to C57BL/6 pregnant mice on E12.5 days. The study included three groups: the VPA Transcutaneous Auricular Stimulation Group (VPA + tVNS), the VPA Control Group (VPA + sham), and the Healthy Control Group (Control + sham). Each group included 16 mice (8 M/8 F). Our results show that serum IL-1β and IL-6 levels were significantly higher in male VPA-exposed mice than controls. However, IL-1β was significantly lower, and IL-6, TNF- α, and IL-22 were not different in female VPA-exposed mice compared to the control group. Brain NLRP3 levels were significantly higher in both sexes in the VPA autism model (P < 0.05). tVNS application increased brain NLRP3 levels in both sexes and reduced serum IL-1β levels in male mice. We conclude that cytokine dysregulation is associated with the VPA-induced adult autism model, and the inflammatory response is more pronounced in male mice. tVNS application altered the inflammatory response and increased brain NLPR3 levels in both sexes. Further studies are needed to understand the beneficial or detrimental role of the inflammatory response in autism and its sexual dimorphism.

Therapeutic Potential of Ocimum basilicum L. Extract in Alleviating Autistic-Like Behaviors Induced by Maternal Separation Stress in Mice: Role of Neuroinflammation and Oxidative Stress

A confluence of genetic, environmental, and epigenetic factors shapes autism spectrum disorder (ASD). Early-life stressors like MS play a contributing role in this multifaceted neurodevelopmental disorder. This research was to explore the efficacy of Ocimum basilicum L. (O.B.) extract in mitigating behaviors reminiscent of autism prompted by maternal separation (MS) stress in male mice, focusing on its impact on neuroinflammation and oxidative stress. MS mice were treated with O.B. extract at varying dosages (20, 40, and 60 mg/kg) from postnatal days (PND) 51-53 to PND 58-60. Behavioral experiments, including the Morris water maze, three-chamber test, shuttle box, and resident-intruder test, were conducted post-treatment. The method of maternal separation involved separating the pups from their mothers for 3 h daily, from PND 2 to PND 14. Molecular analysis of hippocampal tissue was performed to assess gene expression of Toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). Hippocampal and serum malondialdehyde (MDA) levels and total antioxidant capacity (TAC) were measured. O.B. extract administration resulted in the amelioration of autistic-like behaviors in MS mice, as evidenced by improved spatial and passive avoidance memories and social interactions, as well as reduced aggression in behavioral tests. O.B. extract attenuated oxidative stress and neuroinflammation, as indicated by decreased MDA and increased TAC levels, as well as downregulation of TLR4, TNF-α, and IL-1β expression in the hippocampus. O.B. extract may offer a novel therapeutic avenue for ASD, potentially mediated through its anti-inflammatory and antioxidant properties.

Blood biomarker discovery for autism spectrum disorder: A proteomic analysis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and social interaction and restricted, repetitive patterns of behavior, interests, or activities. Given the lack of specific pharmacological therapy for ASD and the clinical heterogeneity of the disorder, current biomarker research efforts are geared mainly toward identifying markers for determining ASD risk or for assisting with a diagnosis. A wide range of putative biological markers for ASD are currently being investigated. Proteomic analyses indicate that the levels of many proteins in plasma/serum are altered in ASD, suggesting that a panel of proteins may provide a blood biomarker for ASD. Serum samples from 76 boys with ASD and 78 typically developing (TD) boys, 2-10 years of age, were analyzed to identify possible early biological markers for ASD. Proteomic analysis of serum was performed using SomaLogic's SOMAScanTM assay 1.3K platform. A total of 1,125 proteins were analyzed. There were 86 downregulated proteins and 52 upregulated proteins in ASD (FDR < 0.05). Combining three different algorithms, we found a panel of 12 proteins that identified ASD with an area under the curve (AUC) = 0.8790±0.0572, with specificity and sensitivity of 0.8530±0.1076 and 0.8324±0.1137, respectively. All 12 proteins were significantly different in ASD compared with TD boys, and 4 were significantly correlated with ASD severity as measured by ADOS total scores. Using machine learning methods, a panel of serum proteins was identified that may be useful as a blood biomarker for ASD in boys. Further verification of the protein biomarker panel with independent test sets is warranted.

Exogenous PD-L1 binds to PD-1 to alleviate and prevent autism-like behaviors in maternal immune activation-induced male offspring mice

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder caused by the interaction of multiple pathogenic factors. Epidemiological studies and animal experiments indicate that maternal immune activation (MIA) is closely related to the development of ASD in offspring. A large number of pro-inflammatory cytokines are transferred from the placenta to the fetal brain during MIA, which impedes fetal neurodevelopment and is accompanied by activation of immune cells and microglia. Programmed cell death protein 1 (PD-1) can be highly expressed on the surface of various activated immune cells, when combined with programmed cell death-ligand 1 (PD-L1), it can activate the PD-1/PD-L1 pathway and exert powerful immunosuppressive effects, suggesting that this immune checkpoint may have the potential to treat MIA-induced ASD. This study combined bioinformatics analysis and experimental validation to explore the efficacy of Fc-fused PD-L1 (PD-L1-Fc) in treating MIA-induced ASD. Bioinformatics analysis results showed that in human placental inflammation, IL-6 was upregulated, T cells proliferated significantly, and the PD-1/PD-L1 pathway was significantly enriched. The experimental results showed that intraperitoneal injection of poly(I:C) induced MIA in pregnant mice resulted in significant expression of IL-6 in their serum, placenta, and fetal brain. At the same time, the expression of PD-1 and PD-L1 in the placenta and fetal brain increased, CD4+ T cells in the spleen were significantly activated, and PD-1 expression increased. Their offspring mice exhibited typical ASD-like behaviors. In vitro experiments on primary microglia of offspring mice have confirmed that the expression of IL-6, PD-1, and PD-L1 is significantly increased, and PD-L1-Fc effectively reduced their expression levels. In the prefrontal cortex of MIA offspring mice, there was an increase in the expression of IL-6, PD-1, and PD-L1; activation of microglial cells, and colocalization with PD-1. Then we administered brain stereotaxic injections of PD-L1-Fc to MIA offspring mice and intraperitoneal injections to MIA pregnant mice. The results indicated that PD-L1-Fc effectively suppressed neuroinflammation in the frontal cortex of offspring mice and partially ameliorated ASD-like behaviors; MIA in pregnant mice was significantly alleviated, and the offspring mice they produced did not exhibit neuroinflammation or ASD-like behaviors. In summary, we have demonstrated the therapeutic ability of PD-L1-Fc for MIA-induced ASD, aiming to provide new strategies and insights for the treatment of ASD.

Alcohol-Induced Activation of Chemokine System and Neuroinflammation Development

Chemokines are immunoregulatory proteins with pleiotropic functions involved in neuromodulation, neurogenesis, and neurotransmission. The way chemokines affect the CNS plays an important role in modulating various conditions that could have negative impact on CNS functions, including development of alcohol use disorders. In this review, we analyzed the literature data available on the problem of chemokine participation in pathogenesis, clinical presentation, and remission of alcohol use disorders both in animal models and in the study of patients with alcoholism. The presented information confirms the hypothesis that the alcohol-induced chemokine production could modulate chronic neuroinflammation. Thus, the data summarized and shown in this review are focused on the relevant direction of research in the field of psychiatry, which is in demand by both scientists and clinical specialists.

Correlation of biochemical markers and inflammatory cytokines in autism spectrum disorder (ASD)

INTRODUCTION

Autism Spectrum Disorder (ASD) is a disorder that severely affects neurodevelopment, and its underlying causes are not yet entirely understood. Research suggests that there may be a connection between the occurrence of ASD and changes in immune responses. This study aims to know if some biochemical and inflammatory cytokines are promising biomarkers for ASD and whether they are involved in the pathogenesis of ASD.

METHODS

The serum levels of CRP, TNF-α, TGF-β, IL-1β, IL-10, 1 L-8, and IL-6 were measured in all of the patients (n = 22) and in the healthy (n = 12) children using ELISA method.

RESULTS

The serum concentrations of IL-10 and IL-8 were significantly lower in the ASD patients compared to the control group (p < 0.05) and there were not significant differences between CRP, TNF-α, TGF-β, IL-6 and IL-1β levels in two groups. There were positive correlations between CRP and IL-10, also CRP and IL-8, in ASD group. In contrast to the ASD patients, the correlations of IL-8, IL-10, and CRP were not significant in the control group.

CONCLUSION

In conclusion, this study highlights the potential role of certain biochemical markers and inflammatory cytokines in ASD. Specifically, the lower levels of IL-10 and IL-8 in ASD patients, along with the significant correlations between CRP and these cytokines, suggest an altered immune response in individuals with ASD. These findings support the hypothesis that immune dysregulation may be involved in ASD pathogenesis. Further research is needed to explore these biomarkers and their mechanistic links to ASD, which could lead to improved diagnostics or therapeutic strategies.

Assessing the biobehavioral effects of ultramicronized-palmitoylethanolamide monotherapy in autistic adults with different severity levels: a report of two cases

Despite promise of its supplementation as both monotherapy and add-on treatment in autism spectrum disorder (ASD), the biobehavioral effects of Palmitoylethanolamide (PEA) in autistic adults have never been explored so far. We discussed the cases of two autistic adults with different degrees of severity (level 1 and level 2) presenting with symptoms of psychic distress, who were treated with ultramicronized-PEA (um-PEA) 600 mg/day monotherapy for a sustained period of 4 months. The level 1 autistic patient showed improved depressive symptoms and social engagement at a 12-week follow-up, in parallel to a tendency toward reduced inflammatory response and enhanced endocannabinoid (eCB) signaling, partially relapsing after um-PEA discontinuation at four months. Opposedly, the level 2 autistic patient exhibited a generally stable psychosocial functioning for the initial 12 weeks, consistent with basically unchanged immune and eCBs levels, abruptly deteriorating and leading to antipsychotic initiation afterwards. No significant side effects were reported in both cases during the observation period. The two cases suggest that um-PEA could be an effective option for the treatment of psychic distress in level 1 autistic adults, warranting further investigation of its age- and level-specificity and of the biological underpinnings of its therapeutic effect in ASD.

Dysregulated plasma autoantibodies are associated with B cell dysfunction in young Arab children with autism spectrum disorder in Qatar

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction and communication, as well as the occurrence of stereotyped and repetitive behaviors. Previous studies have provided solid evidence of dysregulated immune system in ASD; however, limited studies have investigated autoantibody profiles in individuals with ASD. This study aims to screen plasma autoantibodies in a well-defined cohort of young children with ASD (n = 100) and their matched controls (n = 60) utilizing a high-throughput KoRectly Expressed (KREX) i-Ome protein-array technology. We identified differential protein expression of 16 autoantibodies in ASD, which were correlated with differential gene expression of these markers in independent ASD cohorts. Meanwhile, we identified a distinct list of 33 autoantibodies associated with ASD severity; several of which were correlated with maternal age and birth weight in ASD. In addition, we found dysregulated numbers of circulating B cells and activated HLADR+ B cells in ASD, which were correlated with altered levels of several autoantibodies. Further in-depth analysis of B cell subpopulations revealed an increased frequency of activated naïve B cells in ASD, as well as an association of resting naïve B cells and transitional B cells with ASD severity. Pathway enrichment analysis revealed disrupted MAPK signaling in ASD, suggesting a potential relevance of this pathway to altered autoantibodies and B cell dysfunction in ASD. Finally, we found that a combination of eight autoantibodies associated with ASD severity showed an area under the curve (ROC-AUC) of 0.937 (95% CI = 0.890, 0.983; p < 0.001), which demonstrated the diagnostic accuracy of the eight-marker signature in the severity classification of ASD cases. Overall, this study determined dysregulated autoantibody profiles and B cell dysfunction in children with ASD and identified an eight-autoantibody panel for ASD severity classification.

Treating reactivated EBV, HHV-6, HHV-7 infections in children with Autism Spectrum disorder associated with genetic folate cycle disruptions: Outcomes after Valacyclovir, Valganciclovir and Artesunate

Immune dysfunction causes the reactivation of herpesviruses in children with autism spectrum disorder (ASD) associated with the genetic folate cycle deficiency (GFCDs). The aim – to investigate the efficacy of valaciclovir, valganciclovir, and artesunate in reactivated Epstein-Barr virus (EBV), herpes virus type 6 (HHV-6) and herpes virus type 7 (HHV-7) infections in children with ASD. The treatment group consisted of 225 children aged 2 to 9 years who had GFCDs and ASD. The diagnosis of EBV, HHV-6, and HHV-7 reactivations was made by blood leukocyte PCR. Valacyclovir (500-1000 mg twice per day), valganciclovir (225-450mg twice per day), and artesunate (25-50mg twice a day) were prescribed for 3 months. The control group (no antiviral treatment) included 52 children who were comparable in age and diagnosis. Valacyclovir treatment achieved undetectable EBV DNA in 39% of cases. Valganciclovir and artesunate performed complete response rates of 47 and 62%, respectively (р<0.05; Z<Z0.05). HHV-6 DNA was undetectable in 29% of valacyclovir-treated patients. Valganciclovir and artesunate achieved complete response rates of 32 and 57%, respectively (p <0.05; Z<Z0.05). HHV-7 DNA was not detected in 24% of valacyclovir-treated patients, but in 35 and 44%, respectively (p <0.05, Z<Z0.05) in valganciclovir and artesunate groups. There was an association found between negative PCR results and normalized S-100 protein and neuron-specific enolase serum concentrations. Antiviral treatments disrupted the natural course of reactivated EBV, HHV-6, and HHV-7 infections in ASD children, exerting a neuroprotective effect, with artesunate being the most effective option and EBV - the most sensitive to antiviral drugs.

Investigating the Role of Gluten Sensitivity in the Etiology of Autism Spectrum Disorder

<b>Background and Objective:</b> Autism Spectrum Disorder (ASD) is a range of neurodevelopmental disabilities that lack a clear etiology. To date, studies investigating the role of immune reactivity to gluten in ASD have been inconsistent. This study aimed to compare levels of gluten reactivity markers in 319 ASD patients to 172 of their unaffected siblings and 322 of unrelated healthy controls (UHC). <b>Materials and Methods:</b> Patients younger than 12 years old diagnosed with ASD via experienced child psychiatrists and neuro-pediatricians were recruited and gluten reactivity markers and gastrointestinal (GI) complaints commonly found in children with ASD were also investigated. Serum levels of anti-gluten and anti-tissue transglutaminase IgA (anti-TTG IgA) were measured via ELISA. <b>Results:</b> No significant differences were detected in IgA levels and IgG levels for anti-TTG among all groups (p<0.05). The anti-gliadin IgG levels were significantly higher in ASD patients and their siblings compared to the UHC group (p<0.05). Also, those IgG levels were not associated with any GI complaints or Electroencephalogram (EEG) abnormalities (p>0.05). <b>Conclusion:</b> The data suggested gluten sensitivity has no role in ASD pathophysiology or its comorbid symptoms.

Linking Environmental Chemicals to Neuroinflammation and Autism Spectrum Disorder: Mechanisms and Implications for Prevention

This article explores the potential link between endocrine-disrupting chemicals (EDCs), neuroinflammation, and the development of autism spectrum disorder (ASD). Neuroinflammation refers to the immune system's response to injury, infection, or disease in the central nervous system. Studies have shown that exposure to EDCs, such as bisphenol A and phthalates, can disrupt normal immune function in the brain, leading to chronic or excessive neuroinflammation. This disruption of immune function can contribute to developing neurological disorders, including ASD. Furthermore, EDCs may activate microglia, increasing pro-inflammatory cytokine production and astroglia-mediated oxidative stress, exacerbating neuroinflammation. EDCs may also modulate the epigenetic profile of cells by methyltransferase expression, thereby affecting neurodevelopment. This article also highlights the importance of reducing exposure to EDCs and advocating for policies and regulations restricting their use. Further research is needed to understand better the mechanisms underlying the link between EDCs, neuroinflammation, and ASD and to develop new treatments for ASD.

Viral infections in etiology of mental disorders: a broad analysis of cytokine profile similarities - a narrative review

The recent pandemic caused by the SARS-CoV-2 virus and the associated mental health complications have renewed scholarly interest in the relationship between viral infections and the development of mental illnesses, a topic that was extensively discussed in the previous century in the context of other viruses, such as influenza. The most probable and analyzable mechanism through which viruses influence the onset of mental illnesses is the inflammation they provoke. Both infections and mental illnesses share a common characteristic: an imbalance in inflammatory factors. In this study, we sought to analyze and compare cytokine profiles in individuals infected with viruses and those suffering from mental illnesses. The objective was to determine whether specific viral diseases can increase the risk of specific mental disorders and whether this risk can be predicted based on the cytokine profile of the viral disease. To this end, we reviewed existing literature, constructed cytokine profiles for various mental and viral diseases, and conducted comparative analyses. The collected data indicate that the risk of developing a specific mental illness cannot be determined solely based on cytokine profiles. However, it was observed that the combination of IL-8 and IL-10 is frequently associated with psychotic symptoms. Therefore, to assess the risk of mental disorders in infected patients, it is imperative to consider the type of virus, the mental complications commonly associated with it, the predominant cytokines to evaluate the risk of psychotic symptoms, and additional patient-specific risk factors.

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.

Autistic Children/Adolescents Have Lower Adherence to the Mediterranean Diet and Higher Salivary IL-6 Concentration: Potential Diet-Inflammation Links?

BACKGROUND

Autism spectrum disorder (ASD) is one of the most prevalent neurodevelopmental disorders. Many patients with ASD often show behavioral problems at mealtimes, including food selectivity and atypical feeding behaviors. The Mediterranean diet (MD) has a beneficial effect on mental health for the general population across different ages. There is evidence that good adherence to the MD is effective in reducing peripheral inflammatory markers, such as the cytokine interleukin-6 (IL-6). The present study was designed to evaluate adherence to the MD in children with ASD using age- and sex-matched, typically developing individuals (TDs) as a control group and to determine whether differences in adherence to the MD are associated with salivary IL-6 and IL-6 receptor concentration.

METHODS

Twenty children and adolescents with ASD (mean age 9.95 ± 0.65 years) and twenty TDs (mean age: 9.85 ± 0.59 years) participated in this study (N = 16 males and N = 4 females in each group). Participants with ASD were enrolled in a psychiatric consultation in Valencia (Spain), and TDs were recruited from two public schools in Valencia. The parents of both ASD and TD groups answered the items in a validated Mediterranean Diet Quality Index for children and adolescents (KIDMED) questionnaire on their children's adherence to the MD.

RESULTS

The mean adherence to MD score was significantly lower in the ASD group (9.10 ± 0.42) (range 6-12) than in the TD group (10.35 ± 0.31) (range 8-12) (p = 0.02, Mann-Whitney U test). There was no statistically significant association between adherence to the MD and age or sex in both groups, but there was a significant correlation between the total KIDMED score and body mass index (BMI) in the ASD group. Regarding the concentration of Il-6 and the Il-6 receptor in saliva samples, there were no significant differences between the two groups; however, linear regression analysis by group revealed significant associations between the adherence to MD score and the concentration of IL-6 and its receptor in saliva in the ASD group (p = 0.003, OR = 0.68, 95% CI 0.007 to -0.02; p = 0.009, OR = -0.64, 95% CI -0.01 to -0.00). In contrast, no significant associations were observed between the adherence to MD score and the concentration of IL-6 and its receptor in saliva in the TD group.

CONCLUSIONS

Children and adolescents with ASD showed significantly lower adherence to the MD, which can contribute to nutritional deficits described in ASD, and the role of BMI composition (fat versus lean mass) needs to be further investigated in this group. The concentration of IL-6 and its receptor in saliva is associated with adherence to the MD, suggesting a possible link between IL-6 and diet in ASD. Further studies to clarify the associations between IL-6, psychiatric alterations, and diet in ASD are needed.

Acute rapamycin treatment reveals novel mechanisms of behavioral, physiological, and functional dysfunction in a maternal inflammation mouse model of autism and sensory over-responsivity

Maternal inflammatory response (MIR) during early gestation in mice induces a cascade of physiological and behavioral changes that have been associated with autism spectrum disorder (ASD). In a prior study and the current one, we find that mild MIR results in chronic systemic and neuro-inflammation, mTOR pathway activation, mild brain overgrowth followed by regionally specific volumetric changes, sensory processing dysregulation, and social and repetitive behavior abnormalities. Prior studies of rapamycin treatment in autism models have focused on chronic treatments that might be expected to alter or prevent physical brain changes. Here, we have focused on the acute effects of rapamycin to uncover novel mechanisms of dysfunction and related to mTOR pathway signaling. We find that within 2 hours, rapamycin treatment could rapidly rescue neuronal hyper-excitability, seizure susceptibility, functional network connectivity and brain community structure, and repetitive behaviors and sensory over-responsivity in adult offspring with persistent brain overgrowth. These CNS-mediated effects are also associated with alteration of the expression of several ASD-,ion channel-, and epilepsy-associated genes, in the same time frame. Our findings suggest that mTOR dysregulation in MIR offspring is a key contributor to various levels of brain dysfunction, including neuronal excitability, altered gene expression in multiple cell types, sensory functional network connectivity, and modulation of information flow. However, we demonstrate that the adult MIR brain is also amenable to rapid normalization of these functional changes which results in the rescue of both core and comorbid ASD behaviors in adult animals without requiring long-term physical alterations to the brain. Thus, restoring excitatory/inhibitory imbalance and sensory functional network modularity may be important targets for therapeutically addressing both primary sensory and social behavior phenotypes, and compensatory repetitive behavior phenotypes.

Platelet Levels of Brain-Derived Neurotrophic Factor in Adults with Autism Spectrum Disorder: Is There a Specific Association with Autism Spectrum Psychopathology?

To date, although several studies have investigated the circulating levels of brain-derived neurotrophic factor (BDNF) in children with autism spectrum disorder (ASD), only a few authors have addressed their evaluation in adults. Furthermore, an important limitation of these studies lies in the fact that circulating BDNF is stored in platelets and released into the circulation when needed. To the best of our knowledge, a very limited number of studies have related peripheral BDNF values to platelet counts, and yet no study has evaluated intra-platelet BDNF levels in adults with ASD. In this framework, the aim of the present work is to pave the way in this field and evaluate platelet BNDF levels in adult ASD patients, as well as their correlation with autistic symptoms and related psychopathological dimensions. We recruited 22 ASD and 22 healthy controls, evaluated with the Adult autism subthreshold spectrum (AdAS Spectrum), the Social Anxiety Spectrum-self report (SHY-SR), the Trauma and loss spectrum-self report (TALS-SR), the Work and Social Adjustment Scale (WSAS), and the Mood Spectrum-self report for suicidality. Intra-platelet BDNF levels were also assessed. The results highlighted lower BDNF levels in the ASD group; moreover, AdAS Spectrum and WSAS total score as well as AdAS Spectrum Restricted interest and rumination, WSAS Private leisure activities, TALS-SR Arousal, and SHY-SR Childhood domains were significant negative predictors of platelet BDNF levels.

In vivo translocator protein in females with autism spectrum disorder: a pilot study

Sex-based differences in the prevalence of autism spectrum disorder (ASD) are well-documented, with a male-to-female ratio of approximately 4:1. The clinical presentation of the core symptoms of ASD can also vary between sexes. Previously, positron emission tomography (PET) studies have identified alterations in the in vivo levels of translocator protein (TSPO)-a mitochondrial protein-in primarily or only male adults with ASD, with our group reporting lower TSPO relative to whole brain mean in males with ASD. However, whether in vivo TSPO levels are altered in females with ASD, specifically, is unknown. This is the first pilot study to measure in vivo TSPO in the brain in adult females with ASD using [11C]PBR28 PET-magnetic resonance imaging (MRI). Twelve adult females with ASD and 10 age- and TSPO genotype-matched controls (CON) completed one or two [11C]PBR28 PET-MRI scans. Females with ASD exhibited elevated [11C]PBR28 standardized uptake value ratio (SUVR) in the midcingulate cortex and splenium of the corpus callosum compared to CON. No brain area showed lower [11C]PBR28 SUVR in females with ASD compared to CON. Test-retest over several months showed stable [11C]PBR28 SUVR across time in both groups. Elevated regional [11C]PBR28 SUVR in females with ASD stand in stark contrast to our previous findings of lower regional [11C]PBR28 SUVR in males with ASD. Preliminary evidence of regionally elevated mitochondrial protein TSPO relative to whole brain mean in ASD females may reflect neuroimmuno-metabolic alterations specific to females with ASD.

Juvenile peripheral LPS exposure overrides female resilience to prenatal VPA effects on adult sociability in mice

Autism spectrum disorder (ASD) exhibits a gender bias, with boys more frequently affected than girls. Similarly, in mouse models induced by prenatal exposure to valproic acid (VPA), males typically display reduced sociability, while females are less affected. Although both males and females exhibit VPA effects on neuroinflammatory parameters, these effects are sex-specific. Notably, females exposed to VPA show increased microglia and astrocyte density during the juvenile period. We hypothesized that these distinct neuroinflammatory patterns contribute to the resilience of females to VPA. To investigate this hypothesis, we treated juvenile animals with intraperitoneal bacterial lipopolysaccharides (LPS), a treatment known to elicit brain neuroinflammation. We thus evaluated the impact of juvenile LPS-induced inflammation on adult sociability and neuroinflammation in female mice prenatally exposed to VPA. Our results demonstrate that VPA-LPS females exhibit social deficits in adulthood, overriding the resilience observed in VPA-saline littermates. Repetitive behavior and anxiety levels were not affected by either treatment. We also evaluated whether the effect on sociability was accompanied by heightened neuroinflammation in the cerebellum and hippocampus. Surprisingly, we observed reduced astrocyte and microglia density in the cerebellum of VPA-LPS animals. These findings shed light on the complex interactions between prenatal insults, juvenile inflammatory stimuli, and sex-specific vulnerability in ASD-related social deficits, providing insights into potential therapeutic interventions for ASD.

Ketogenic Diet Induced Shifts in the Gut Microbiome Associate with Changes to Inflammatory Cytokines and Brain-Related miRNAs in Children with Autism Spectrum Disorder

In this interventional pilot study, we investigated the effects of a modified ketogenic diet (KD) on children with autism spectrum disorder (ASD). We previously observed improved behavioral symptoms in this cohort following the KD; this trial was registered with Clinicaltrials.gov (NCT02477904). This report details the alterations observed in the microbiota, inflammation markers, and microRNAs of seven children following a KD for a duration of 4 months. Our analysis included blood and stool samples, collected before and after the KD. After 4 months follow up, we found that the KD led to decreased plasma levels of proinflammatory cytokines (IL-12p70 and IL-1b) and brain-derived neurotrophic factor (BDNF). Additionally, we observed changes in the gut microbiome, increased expression of butyrate kinase in the gut, and altered levels of BDNF-associated miRNAs in the plasma. These cohort findings suggest that the KD may positively influence ASD sociability, as previously observed, by reducing inflammation, reversing gut microbial dysbiosis, and impacting the BDNF pathway related to brain activity.

Oxytocin-induced increases in cytokines and clinical effect on the core social features of autism: Analyses of RCT datasets

Although oxytocin may provide a novel therapeutics for the core features of autism spectrum disorder (ASD), previous results regarding the efficacy of repeated or higher dose oxytocin are controversial, and the underlying mechanisms remain unclear. The current study is aimed to clarify whether repeated oxytocin alter plasma cytokine levels in relation to clinical changes of autism social core feature. Here we analyzed cytokine concentrations using comprehensive proteomics of plasmas of 207 adult males with high-functioning ASD collected from two independent multi-center large-scale randomized controlled trials (RCTs): Testing effects of 4-week intranasal administrations of TTA-121 (A novel oxytocin spray with enhanced bioavailability: 3U, 6U, 10U, or 20U/day) and placebo in the crossover discovery RCT; 48U/day Syntocinon or placebo in the parallel-group verification RCT. Among the successfully quantified 17 cytokines, 4 weeks TTA-121 6U (the peak dose for clinical effects) significantly elevated IL-7 (9.74, 95 % confidence interval [CI] 3.59 to 15.90, False discovery rate corrected P (PFDR) < 0.001), IL-9 (56.64, 20.46 to 92.82, PFDR < 0.001) and MIP-1b (18.27, 4.96 to 31.57, PFDR < 0.001) compared with placebo. Inverted U-shape dose-response relationships peaking at TTA-121 6U were consistently observed for all these cytokines (IL-7: P < 0.001; IL-9: P < 0.001; MIP-1b: P = 0.002). Increased IL-7 and IL-9 in participants with ASD after 4 weeks TTA-121 6U administration compared with placebo was verified in the confirmatory analyses in the dataset before crossover (PFDR < 0.001). Furthermore, the changes in all these cytokines during 4 weeks of TTA-121 10U administration revealed associations with changes in reciprocity score, the original primary outcome, observed during the same period (IL-7: Coefficient = -0.05, -0.10 to 0.003, P = 0.067; IL-9: -0.01, -0.02 to -0.003, P = 0.005; MIP-1b: -0.02, -0.04 to -0.007, P = 0.005). These findings provide the first evidence for a role of interaction between oxytocin and neuroinflammation in the change of ASD core social features, and support the potential role of this interaction as a novel therapeutic seed. Trial registration: UMIN000015264, NCT03466671/UMIN000031412.

Association between platelet indices and non-alcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Platelet indices have the potential for the evaluation of the activity of non-alcoholic fatty liver disease (NAFLD), but their associations are under hard debate. This meta-analysis aims to assess whether platelet count (PC), mean platelet volume (MPV) and platelet distribution width (PDW) are associated with NAFLD and its progression.

METHODS

A literature search was conducted using electronic databases to find publications up to July 2022, where the relationship between PC, MPV, PDW and NAFLD was evaluated. Random-effects models were applied to pool effect estimates that were presented as standardized mean differences (SMD) with 95% confidence interval (CI).

RESULTS

Nineteen studies involving 3592 NAFLD patients and 1194 healthy individuals were included. The pooled results showed that NAFLD patients had a lower PC (SMD=-0.66, 95% CI =-1.22 to -0.09, P=0.023) but a higher MPV (SMD=0.89, 95% CI=0.26-1.51, P=0.005) and PDW (SMD=0.55, 95% CI=0.11-0.99, P=0.014) compared to healthy controls. Patients with non-alcoholic steatohepatitis (NASH) exhibited a lower PC (SMD=-0.86, 95% CI=-1.20 to -0.52, P<0.001) and a higher MPV (SMD=0.71, 95% CI=0.40-1.02, P<0.001) than non-NASH individuals. A meta-regression analysis demonstrated that MPV was significantly positively correlated with aspartate aminotransferase (P=0.008), the total cholesterol (P=0.003), triglyceride (P=0.006) and low-density lipoprotein cholesterol (P=0.007), but was significantly negatively correlated with high-density lipoprotein cholesterol (P=0.010).

CONCLUSION

This meta-analysis revealed that NAFLD patients presented a reduced PC but an increased MPV and PDW, and the changes might be associated with NAFLD severity. A higher MPV is associated with lipid metabolic disorders in NAFLD.

Ameliorating effect of pioglitazone on prenatal valproic acid-induced behavioral and neurobiological abnormalities in autism spectrum disorder in rats

Autism spectrum disorder (ASD) is a neurodevelopment disorder that mainly arises due to abnormalities in different brain regions, resulting in behavioral deficits. Besides its diverse phenotypical features, ASD is associated with complex and varied etiology, presenting challenges in understanding its precise neuro-pathophysiology. Pioglitazone was reported to have a fundamental role in neuroprotection in various other neurological disorders. The present study aimed to investigate the therapeutic potential of pioglitazone in the prenatal valproic acid (VPA)-model of ASD in Wistar rats. Pregnant female Wistar rats received VPA on Embryonic day (E.D12.5) to induce autistic-like-behavioral and neurobiological alterations in their offspring. VPA-exposed rats presented core behavioral symptoms of ASD such as deficits in social interaction, poor spatial and learning behavior, increased anxiety, locomotory and repetitive activity, and decreased exploratory activity. Apart from these, VPA exposure also stimulated neurochemical and histopathological neurodegeneration in various brain regions. We administered three different doses of pioglitazone i.e., 2.5, 5, and 10 mg/kg in rats to assess various parameters. Of all the doses, our study highlighted that 10 mg/kg pioglitazone efficiently attenuated the autistic symptoms along with other neurochemical alterations such as oxidative stress, neuroinflammation, and apoptosis. Moreover, pioglitazone significantly attenuated the neurodegeneration by restoring the neuronal loss in the hippocampus and cerebellum. Taken together, our study suggests that pioglitazone exhibits therapeutic potential in alleviating behavioral abnormalities induced by prenatal VPA exposure in rats. However, further research is needed to fully understand and establish pioglitazone's effectiveness in treating ASD.

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.

Influence of maternal immune activation on autism-like symptoms and coping strategies in male offspring

Maternal immune activation (MIA) caused by exposure to pathogens or inflammation during critical periods of gestation increased susceptibility to neurodevelopmental disorders, including autism, in the offspring. In the present work, we aimed to provide characterization of the long-term consequences on anxiety-like behavior and cardiovascular stress response of MIA in the offspring. This study aimed to evaluate the effect of MIA by lipopolysaccharide (LPS) in adult male offspring. In our study, the animals were subjected to a range of behavioral and physiological tests, including the elevated plus maze, social interaction, cat odor response, open field behavior, contextual fear conditioning, and cardiovascular responses during restraint stress. In the offspring of MIA, our study unveiled distinct anxious behaviors. This was evident by fewer entries into the open arms of the maze, diminished anti-thigmotaxis in the open field, and a decrease in social interaction time. Moreover, these rats showed heightened sensitivity to cat odor, exhibited prolonged freezing during fear conditioning, and presented elevated 22 Hz ultrasonic vocalizations. Notably, during restraint stress, these animals manifested an augmented blood pressure response, and this was associated with an increase in c-fos expression in the locus coeruleus compared to the control group. These findings collectively underline the extensive behavioral and physiological alterations stemming from MIA. This study deepens our understanding of the significance of maternal health in predisposing offspring to neurobehavioral deficits and psychiatric disorders.

Autism spectrum disorder: pathogenesis, biomarker, and intervention therapy

Autism spectrum disorder (ASD) has become a common neurodevelopmental disorder. The heterogeneity of ASD poses great challenges for its research and clinical translation. On the basis of reviewing the heterogeneity of ASD, this review systematically summarized the current status and progress of pathogenesis, diagnostic markers, and interventions for ASD. We provided an overview of the ASD molecular mechanisms identified by multi-omics studies and convergent mechanism in different genetic backgrounds. The comorbidities, mechanisms associated with important physiological and metabolic abnormalities (i.e., inflammation, immunity, oxidative stress, and mitochondrial dysfunction), and gut microbial disorder in ASD were reviewed. The non-targeted omics and targeting studies of diagnostic markers for ASD were also reviewed. Moreover, we summarized the progress and methods of behavioral and educational interventions, intervention methods related to technological devices, and research on medical interventions and potential drug targets. This review highlighted the application of high-throughput omics methods in ASD research and emphasized the importance of seeking homogeneity from heterogeneity and exploring the convergence of disease mechanisms, biomarkers, and intervention approaches, and proposes that taking into account individuality and commonality may be the key to achieve accurate diagnosis and treatment of ASD.

Mast Cells in Autism Spectrum Disorder-The Enigma to Be Solved?

Autism Spectrum Disorder (ASD) is a disturbance of neurodevelopment with a complicated pathogenesis and unidentified etiology. Many children with ASD have a history of "allergic symptoms", often in the absence of mast cell (MC)-positive tests. Activation of MCs by various stimuli may release molecules related to inflammation and neurotoxicity, contributing to the development of ASD. The aim of the present paper is to enrich the current knowledge on the relationship between MCs and ASD by discussing key molecules and immune pathways associated with MCs in the pathogenesis of autism. Cytokines, essential marker molecules for MC degranulation and therapeutic targets, are also highlighted. Understanding the relationship between ASD and the activation of MCs, as well as the involved molecules and interactions, are the main points contributing to solving the enigma. Key molecules, associated with MCs, may provide new insights to the discovery of drug targets for modeling inflammation in ASD.

Mapping autism's research landscape: trends in autism screening and its alignment with sustainable development goals

Introduction

Autism Spectrum Disorder is a complex neurodevelopmental syndrome that profoundly affects social interactions, communication, and sensory perception. The research traced the evolution of autism research from 2011-2022, specifically focusing on the screening and diagnosis of children and students.

Methods

Through an analysis of 12,262 publications using the PRISMA framework, bibliographic coupling, science mapping, and citation analysis, this study illuminates the growth trajectory of ASD research and significant disparities in diagnosis and services.

Results

The study indicates an increasing trend in autism research, with a strong representation of female authorship. Open Access journals show a higher average citation impact compared to their closed counterparts. A keyword co-occurrence analysis revealed four central research themes: Child Development and Support Systems, Early Identification and Intervention, Prevalence and Etiology, and Mental Health. The pandemic's onset has prioritized research areas like mental health, telehealth, and service accessibility.

Discussion

Recommendations on a global level stress the importance of developing timely biological markers for ASD, amplifying Disability Inclusion research, and personalizing mental health services to bridge these critical service gaps. These strategies, underpinned by interdisciplinary collaboration and telehealth innovation, particularly in low-resource settings, can offer a roadmap for inclusive, context-sensitive interventions at local levels that directly support SDG3's aim for health and well-being for all.

Neurodevelopmental and Neuropsychiatric Disorders

This chapter will focus on microglial involvement in neurodevelopmental and neuropsychiatric disorders, particularly autism spectrum disorder (ASD), schizophrenia and major depressive disorder (MDD). We will describe the neuroimmune risk factors that contribute to the etiopathology of these disorders across the lifespan, including both in early life and adulthood. Microglia, being the resident immune cells of the central nervous system, could play a key role in triggering and determining the outcome of these disorders. This chapter will review preclinical and clinical findings where microglial morphology and function were examined in the contexts of ASD, schizophrenia and MDD. Clinical evidence points out to altered microglial morphology and reactivity, as well as increased expression of pro-inflammatory cytokines, supporting the idea that microglial abnormalities are involved in these disorders. Indeed, animal models for these disorders found altered microglial morphology and homeostatic functions which resulted in behaviours related to these disorders. Additionally, as microglia have emerged as promising therapeutic targets, we will also address in this chapter therapies involving microglial mechanisms for the treatment of neurodevelopmental and neuropsychiatric disorders.

The Interplay of Astrocytes and Neurons in Autism Spectrum Disorder

Autism spectrum disorder (ASD) comprises a complex neurodevelopmental condition characterized by an impairment in social interaction, involving communication deficits and specific patterns of behaviors, like repetitive behaviors. ASD is clinically diagnosed and usually takes time, typically occurring not before four years of age. Genetic mutations affecting synaptic transmission, such as neuroligin and neurexin, are associated with ASD and contribute to behavioral and cognitive deficits. Recent research highlights the role of astrocytes, the brain's most abundant glial cells, in ASD pathology. Aberrant Ca2+ signaling in astrocytes is linked to behavioral deficits and neuroinflammation. Notably, the cytokine IL-6 overexpression by astrocytes impacts synaptogenesis. Altered neurotransmitter levels, disruptions in the blood-brain barrier, and cytokine dysregulation further contribute to ASD complexity. Understanding these astrocyte-related mechanisms holds promise for identifying ASD subtypes and developing targeted therapies.

Is the efficacy of oxytocin for autism diminished at higher dosages or repeated doses?: Potential mechanisms and candidate solutions

No approved pharmacological intervention currently exists to address the core symptoms of autism spectrum disorder, a prevalent neurodevelopmental condition. However, there is a growing body of empirical evidence highlighting oxytocin's modulatory effects on social and communicative behaviors. Numerous single-dose trials have consistently demonstrated the efficacy of oxytocin in ameliorating behavioral and neural measurements associated with the core symptoms of autism spectrum disorder. Nevertheless, prior investigations involving the repeated administration of oxytocin have yielded disparate findings concerning its effectiveness, particularly in relation to clinical measures of the core symptoms of autism spectrum disorder. Recent studies have also raised the possibility of diminishing efficacy of oxytocin over time, particularly when higher or recurrent dosages of oxytocin are administered. This review article aims to provide an overview of previous studies examining this issue. Furthermore, it aims to discuss the potential mechanisms underlying these effects, including the interaction between oxytocin and vasopressin, as well as potential strategies for addressing the challenges mentioned. This review's overall objective is to provide insights into the potential development of innovative therapeutics to mitigate the core symptoms of autism spectrum disorder, representing potential breakthroughs in the treatment of this complex neurodevelopmental condition.

Gonadal hormones impart male-biased behavioral vulnerabilities to immune activation via microglial mitochondrial function

There is a strong male bias in the prevalence of many neurodevelopmental disorders such as autism spectrum disorder. However, the mechanisms underlying this sex bias remain elusive. Infection during the perinatal period is associated with an increased risk of neurodevelopmental disorder development. Here, we used a mouse model of early-life immune activation that reliably induces deficits in social behaviors only in males. We demonstrate that male-biased alterations in social behavior are dependent upon microglial immune signaling and are coupled to alterations in mitochondrial morphology, gene expression, and function specifically within microglia, the innate immune cells of the brain. Additionally, we show that this behavioral and microglial mitochondrial vulnerability to early-life immune activation is programmed by the male-typical perinatal gonadal hormone surge. These findings demonstrate that social behavior in males over the lifespan are regulated by microglia-specific mechanisms that are shaped by events that occur in early development.

Pre-autism: What a paediatrician should know about early diagnosis of autism‎

Autism, also known as an autism spectrum disorder, is a complex neurodevelopmental disorder usually diagnosed in the first three years of a child's life. A range of symptoms characterizes it and can be diagnosed at any age, including adolescence and adulthood. However, early diagnosis is crucial for effective management, prognosis, and care. Unfortunately, there are no established fetal, prenatal, or newborn screening programs for autism, making early detection difficult. This review aims to shed light on the early detection of autism prenatally, natally, and early in life, during a stage we call as "pre-autism" when typical symptoms are not yet apparent. Some fetal, neonatal, and infant biomarkers may predict an increased risk of autism in the coming baby. By developing a biomarker array, we can create an objective diagnostic tool to diagnose and rank the severity of autism for each patient. These biomarkers could be genetic, immunological, hormonal, metabolic, amino acids, acute phase reactants, neonatal brainstem function biophysical activity, behavioral profile, body measurements, or radiological markers. However, every biomarker has its accuracy and limitations. Several factors can make early detection of autism a real challenge. To improve early detection, we need to overcome various challenges, such as raising community awareness of early signs of autism, improving access to diagnostic tools, reducing the stigma attached to the diagnosis of autism, and addressing various culturally sensitive concepts related to the disorder.

The tryptophan catabolite or kynurenine pathway in autism spectrum disorder; a systematic review and meta-analysis

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication and interaction, as well as rigid and unchanging interests and behaviors. Several studies have reported that activated immune-inflammatory and nitro-oxidative pathways are accompanied by depletion of plasma tryptophan (TRP), increased competing amino acid (CAAs) levels, and activation of the TRP catabolite (TRYCAT) pathway. This study aims to systematically review and meta-analyze data on peripheral TRP, CAAs, TRYCAT pathway activity, and individual TRYCATs, including kynurenine (KYN) and kynurenic acid (KA) levels, in the blood and urine of ASD patients. After extensively searching PubMed, Google Scholar, and SciFinder, a total of 25 full-text papers were included in the analysis, with a total of 6653 participants (3557 people with ASD and 3096 healthy controls). Our results indicate that blood TRP and the TRP/CAAs ratio were not significantly different between ASD patients and controls (standardized mean difference, SMD = -0.227, 95% confidence interval, CI: -0.540; 0.085, and SMD = 0.158, 95% CI: -0.042; 0.359), respectively. The KYN/TRP ratio showed no significant difference between ASD and controls (SMD = 0.001, 95% CI: -0.169; 0.171). Blood KYN and KA levels were not significantly changed in ASD. Moreover, there were no significant differences in urine TRP, KYN, and KA levels between ASD and controls. We could not establish increases in neurotoxic TRYCATs in ASD. In conclusion, this study demonstrates no abnormalities in peripheral blood TRP metabolism, indoleamine 2,3-dioxygenase enzyme (IDO) activity, or TRYCAT production in ASD. Reduced TRP availability and elevated neurotoxic TRYCAT levels are not substantial contributors to ASD's pathophysiology.

Microglia depletion ameliorates neuroinflammation, anxiety-like behavior, and cognitive deficits in a sex-specific manner in Rev-erbα knockout mice

The circadian system is an evolutionarily adaptive system that synchronizes biological and physiological activities within the body to the 24 h oscillations on Earth. At the molecular level, circadian clock proteins are transcriptional factors that regulate the rhythmic expression of genes involved in numerous physiological processes such as sleep, cognition, mood, and immune function. Environmental and genetic disruption of the circadian clock can lead to pathology. For example, global deletion of the circadian clock gene Rev-erbα (RKO) leads to hyperlocomotion, increased anxiety-like behaviors, and cognitive impairments in male mice; however, the mechanisms underlying behavioral changes remain unclear. Here we hypothesized that RKO alters microglia function leading to neuroinflammation and altered mood and cognition, and that microglia depletion can resolve neuroinflammation and restore behavior. We show that microglia depletion (CSF1R inhibitor, PLX5622) in 8-month-old RKO mice ameliorated hyperactivity, memory impairments, and anxiety/risky-like behaviors. RKO mice exhibited striking increases in expression of pro-inflammatory cytokines (e.g., IL-1β and IL-6). Surprisingly, these increases were only fully reversed by microglia depletion in the male but not female RKO hippocampus. In contrast, male RKO mice showed greater alterations in microglial morphology and phagocytic activity than females. In both sexes, microglia depletion reduced microglial branching and decreased CD68 production without altering astrogliosis. Taken together, we show that male and female RKO mice exhibit unique perturbations to the neuroimmune system, but microglia depletion is effective at rescuing aspects of behavioral changes in both sexes. These results demonstrate that microglia are involved in Rev-erbα-mediated changes in behavior and neuroinflammation.

(R)-ketamine attenuates neurodevelopmental disease-related phenotypes in a mouse model of maternal immune activation

Infections during pregnancy are associated with an increased risk of neuropsychiatric disorders with developmental etiologies, such as schizophrenia and autism spectrum disorders (ASD). Studies have shown that the animal model of maternal immune activation (MIA) reproduces a wide range of phenotypes relevant to the study of neurodevelopmental disorders. Emerging evidence shows that (R)-ketamine attenuates behavioral, cellular, and molecular changes observed in animal models of neuropsychiatric disorders. Here, we investigate whether (R)-ketamine administration during adolescence attenuates some of the phenotypes related to neurodevelopmental disorders in an animal model of MIA. For MIA, pregnant Swiss mice received intraperitoneally (i.p.) lipopolysaccharide (LPS; 100 µg/kg/day) or saline on gestational days 15 and 16. The two MIA-based groups of male offspring received (R)-ketamine (20 mg/kg/day; i.p.) or saline from postnatal day (PND) 36 to 50. At PND 62, the animals were examined for anxiety-like behavior and locomotor activity in the open-field test (OFT), as well as in the social interaction test (SIT). At PND 63, the prefrontal cortex (PFC) was collected for analysis of oxidative balance and gene expression of the cytokines IL-1β, IL-6, and TGF-β1. We show that (R)-ketamine abolishes anxiety-related behavior and social interaction deficits induced by MIA. Additionally, (R)-ketamine attenuated the increase in lipid peroxidation and the cytokines in the PFC of the offspring exposed to MIA. The present work suggests that (R)-ketamine administration may have a long-lasting attenuation in deficits in emotional behavior induced by MIA, and that these effects may be attributed to its antioxidant and anti-inflammatory activity in the PFC.

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.

Extracellular free water elevations are associated with brain volume and maternal cytokine response in a longitudinal nonhuman primate maternal immune activation model

Maternal infection has emerged as an important environmental risk factor for neurodevelopmental disorders, including schizophrenia and autism spectrum disorders. Animal model systems of maternal immune activation (MIA) suggest that the maternal immune response plays a significant role in the offspring's neurodevelopment and behavioral outcomes. Extracellular free water is a measure of freely diffusing water in the brain that may be associated with neuroinflammation and impacted by MIA. The present study evaluates the brain diffusion characteristics of male rhesus monkeys (Macaca mulatta) born to MIA-exposed dams (n = 14) treated with a modified form of the viral mimic polyinosinic:polycytidylic acid at the end of the first trimester. Control dams received saline injections at the end of the first trimester (n = 10) or were untreated (n = 4). Offspring underwent diffusion MRI scans at 6, 12, 24, 36, and 45 months. Offspring born to MIA-exposed dams showed significantly increased extracellular free water in cingulate cortex gray matter starting as early as 6 months of age and persisting through 45 months. In addition, offspring gray matter free water in this region was significantly correlated with the magnitude of the maternal IL-6 response in the MIA-exposed dams. Significant correlations between brain volume and extracellular free water in the MIA-exposed offspring also indicate converging, multimodal evidence of the impact of MIA on brain development. These findings provide strong evidence for the construct validity of the nonhuman primate MIA model as a system of relevance for investigating the pathophysiology of human neurodevelopmental psychiatric disorders. Elevated free water in individuals exposed to immune activation in utero could represent an early marker of a perturbed or vulnerable neurodevelopmental trajectory.

Liposomal Epigallocatechin-3-Gallate for the Treatment of Intestinal Dysbiosis in Children with Autism Spectrum Disorder: A Comprehensive Review

Autism Spectrum Disorder (ASD) is characterized by varying degrees of difficulty in social interaction and communication. These deficits are often associated with gastrointestinal symptoms, indicating alterations in both intestinal microbiota composition and metabolic activities. The intestinal microbiota influences the function and development of the nervous system. In individuals with ASD, there is an increase in bacterial genera such as Clostridium, as well as species involved in the synthesis of branched-chain amino acids (BCAA) like Prevotella copri. Conversely, decreased amounts of Akkermansia muciniphila and Bifidobacterium spp. are observed. Epigallocatechin-3-gallate (EGCG) is one of the polyphenols with the greatest beneficial activity on microbial growth, and its consumption is associated with reduced psychological distress. Therefore, the objective of this review is to analyze how EGCG and its metabolites can improve the microbial dysbiosis present in ASD and its impact on the pathology. The analysis reveals that EGCG inhibits the growth of pathogenic bacteria like Clostridium perfringens and Clostridium difficile. Moreover, it increases the abundance of Bifidobacterium spp. and Akkermansia spp. As a result, EGCG demonstrates efficacy in increasing the production of metabolites involved in maintaining epithelial integrity and improving brain function. This identifies EGCG as highly promising for complementary treatment in ASD.

Peripheral Inflammatory Markers in Autism Spectrum Disorder and Attention Deficit/Hyperactivity Disorder at Adolescent Age

Autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) are associated with immune dysregulation. We aimed to estimate the pro- and anti-inflammatory activity/balance in ASD and ADHD patients at a little-studied adolescent age with respect to sex. We evaluated 20 ASD patients (5 girls, average age: 12.4 ± 1.9 y), 20 ADHD patients (5 girls, average age: 13.4 ± 1.8 y), and 20 age- and gender-matched controls (average age: 13.2 ± 1.9 y). The evaluated parameters included (1) white blood cells (WBCs), neutrophils, monocytes, lymphocytes, platelets, platelet distribution width (PDW), mean platelet volume, and derived ratios, as well as (2) cytokines-interferon-gamma, interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, and IL-10, tumor necrosis factor-alpha (TNF-α), and derived profiles and ratios. ASD adolescents showed higher levels of WBC, monocytes, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, and IL-10, macrophages (M)1 profile, and anti-inflammatory profile than the controls, with ASD males showing higher monocytes, IL-6 and IL-10, anti-inflammatory profile, and a lower T-helper (Th)1/Th2+T-regulatory cell ratio than control males. The ADHD adolescents showed higher levels of PDW, IL-1β and IL-6, TNF-α, M1 profile, proinflammatory profile, and pro-/anti-inflammatory ratio than the controls, with ADHD females showing a higher TNF-α and pro-/anti-inflammatory ratio than the control females and ADHD males showing higher levels of IL-1β and IL-6, TNF-α, and M1 profile than the control males. Immune dysregulation appeared to be different for both neurodevelopmental disorders in adolescence.

Inflammation, Dopaminergic Brain and Bilirubin

Dopamine is a well-known neurotransmitter due to its involvement in Parkinson's disease (PD). Dopamine is not only involved in PD but also controls multiple mental and physical activities, such as the pleasure of food, friends and loved ones, music, art, mood, cognition, motivation, fear, affective disorders, addiction, attention deficit disorder, depression, and schizophrenia. Dopaminergic neurons (DOPAn) are susceptible to stressors, and inflammation is a recognized risk for neuronal malfunctioning and cell death in major neurodegenerative diseases. Less is known for non-neurodegenerative conditions. Among the endogenous defenses, bilirubin, a heme metabolite, has been shown to possess important anti-inflammatory activity and, most importantly, to prevent DOPAn demise in an ex vivo model of PD by acting on the tumor necrosis factor-alpha (TNFα). This review summarizes the evidence linking DOPAn, inflammation (when possible, specifically TNFα), and bilirubin as an anti-inflammatory in order to understand what is known, the gaps that need filling, and the hypotheses of anti-inflammatory strategies to preserve dopamine homeostasis with bilirubin included.