Serum levels of SOD and risk of autism spectrum disorder: A case‐control study

Potential Neuroprotective Effect of Melatonin in the Hippocampus of Male BTBR Mice

Autism spectrum disorder (ASD) is a neurodevelopmental disorder identified by impairments in common social interactions and repetitive behaviors. In ASD patients, substantial morphological alterations have been observed in the hippocampus, which represents an important region for the development of social skills. Melatonin, commonly found in many foods and plants, is also produced by the pineal gland. This indolamine, known to regulate the circadian rhythm, shows antioxidant and anti-inflammatory properties. We therefore hypothesized that melatonin may reduce oxidative stress and inflammation in the hippocampus of ASD patients. We explored our hypothesis using the BTBR mouse, a well-regarded murine transgenic model for ASD. Immediately after weaning, male BTBR and C57BL/6 mice underwent an 8-week treatment with melatonin or vehicle. Later, through immunohistochemistry and the immunoblotting analysis of the hippocampus, we evaluated the overall expression and cellular localization of Nrf2 and SOD1, two enzymes involved in the oxidative stress response. Similarly, we evaluated NLRP3 and NFkB, two mediators of inflammation, and GAD67, an enzyme responsible for the synthesis of GABA. Ultimately, we addressed melatonin's potential to regulate iron metabolism through a DAB-enhanced Perls reaction assay. Results showed melatonin's potential for modulating the analyzed markers in BTBR mice, suggesting a potential neuroprotective effect in ASD patients.

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.

Concurrent Assessment of Oxidative Stress and MT-ATP6 Gene Profiling to Facilitate Diagnosis of Autism Spectrum Disorder (ASD) in Tamil Nadu Population

Autism spectrum disorder (ASD) is a neurodevelopmental disability that causes social impairment, debilitated verbal or nonverbal conversation, and restricted/repeated behavior. Recent research reveals that mitochondrial dysfunction and oxidative stress might play a pivotal role in ASD condition. The goal of this case-control study was to investigate oxidative stress and related alterations in ASD patients. In addition, the impact of mitochondrial DNA (mtDNA) mutations, particularly MT-ATP6, and its link with oxidative stress in ASD was studied. We found that ASD patient's plasma had lower superoxide dismutase (SOD) and higher catalase (CAT) activity, resulting in lower SOD/CAT ratio. MT-ATP6 mutation analysis revealed that four variations, 8865 G>A, 8684 C>T, 8697 G>A, and 8836 A>G, have a frequency of more than 10% with missense and synonymous (silent) mutations. It was observed that abnormalities in mitochondrial complexes (I, III, V) are more common in ASD, and it may have resulted in MT-ATP6 changes or vice versa. In conclusion, our findings authenticate that oxidative stress and genetics both have an equal and potential role behind ASD and we recommend to conduct more such concurrent research to understand their unique mechanism for better diagnosis and therapeutic for ASD.

Oxidative Stress in Autism Spectrum Disorder-Current Progress of Mechanisms and Biomarkers

Autism spectrum disorder (ASD) is a type of neurodevelopmental disorder that has been diagnosed in an increasing number of children around the world. Existing data suggest that early diagnosis and intervention can improve ASD outcomes. However, the causes of ASD remain complex and unclear, and there are currently no clinical biomarkers for autism spectrum disorder. More mechanisms and biomarkers of autism have been found with the development of advanced technology such as mass spectrometry. Many recent studies have found a link between ASD and elevated oxidative stress, which may play a role in its development. ASD is caused by oxidative stress in several ways, including protein post-translational changes (e.g., carbonylation), abnormal metabolism (e.g., lipid peroxidation), and toxic buildup [e.g., reactive oxygen species (ROS)]. To detect elevated oxidative stress in ASD, various biomarkers have been developed and employed. This article summarizes recent studies about the mechanisms and biomarkers of oxidative stress. Potential biomarkers identified in this study could be used for early diagnosis and evaluation of ASD intervention, as well as to inform and target ASD pharmacological or nutritional treatment interventions.

The Effects of Resveratrol on Oxidative Stress Markers: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

OBJECTIVE

Recent trial studies have found that resveratrol supplementation beneficially reduces oxidative stress marker, but, there is no definitive consensus on this context. The present systematic review and meta-analysis aimed to investigate the effect of resveratrol supplementation on oxidative stress parameters.

METHODS

We searched databases of Pubmed, Scopus and Cochrane Library up to December 2018 with no language restriction. Studies were reviewed according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) and Cochrane handbook. To compare the effects of resveratrol with placebo, weighted mean difference (WMD) with 95% confidence intervals (CI) were pooled based on the random-effects model.

RESULTS

Among sixteen clinical trials, we found that resveratrol supplementation increased GPx serum levels significantly (WMD: 18.61; 95% CI: 8.70 to 28.52; P<0.001) but had no significant effect on SOD concentrations (WMD: 1.01; 95% CI: -0.72 to 2.74; P= 0.25), MDA serum levels (WMD: -1.43; 95% CI: -3.46 to 0.61; P = 0.17) and TAC (WMD: -0.09; 95% CI: -0.29 to 0.11; P = 0.36) compared to placebo. Finally, we observed that resveratrol supplementation may not have a clinically significant effect on oxidative stress.

CONCLUSION

However, the number of human trials is limited in this context, and further large prospective clinical trials are needed to confirm the effect of resveratrol supplement on oxidative stress markers.

Urinary and Plasma Antioxidants in Behavioral Symptoms of Individuals With Autism Spectrum Disorder

The balance between antioxidant capacity and oxidative stress-induced free radicals may be crucial in the pathophysiological development factor of autism spectrum disorder (ASD). We measured the following urinary and plasma biomarker levels of oxidative stress and antioxidants. As urinary biomarkers, (1) hexanoyl-lysine (HEL), which is a new biomarker of oxidative stress, (2) the total antioxidant capacity (TAC), and (3) 8-hydroxy-2'-deoxyguanosine (8-OHdG), as a product of oxidative modifications to DNA; and the plasma levels of (4) the antioxidant protein superoxide dismutase (SOD), which is the crucial defense again oxygen reactive species, and (5) transferrin and (6) ceruloplasmin, which are biomarkers of iron and copper neurotransmission and oxidant-antioxidant systems. We examined the relationship between these urinary and plasma biomarkers and behavioral symptoms in 19 individuals with ASD (mean age, 10.8 ± 5.2 years) and 10 age-matched healthy controls (mean age, 14.2 ± 7.0 years). Behavioral symptoms were estimated using the Aberrant Behavior Checklist (ABC). Urinary TAC levels were significantly lower, whereas urinary HEL levels were significantly increased in the ASD group as compared with the control group. The five ABC subscale and total scores were significantly raised in the autism group than in the control group. The results of a linear regression analysis revealed that plasma SOD levels may be a more accurate predictor of differences in ABC scores between individuals with ASD and control individuals. The present study firstly revealed the important findings that the cooperation between the urinary antioxidant TAC and plasma SOD levels may contribute to the ABC subscale scores of stereotypy. Urinary TAC activity and antioxidant protein SOD may be associated with incomplete mineral body store and antioxidant-related transcription factor and browning reactions. Consequently, a critical imbalance between TAC urinary levels and plasma SOD levels may be an important contributor to autistic behavioral symptoms.

High KEAP1, NRF2 and Low HO-1 Serum Levels in Children with Autism

Introduction

The purpose of our study was to investigate heme oxygenase-1 (HO-1), nuclear factor erythroid-2-related factor 2 (NRF2), and kelch-like ECH-associated protein 1 (KEAP1) levels in children with autism spectrum disorder (ASD) and to reveal their association with the severity of autism.

Methods

This study measured serum HO-1, KEAP1, and NRF2 levels in 43 patients with ASD (aged 3-12 years) and in 41 age- and gender-matched healthy controls. ASD severity was rated using the Childhood Autism Rating Scale (CARS). HO-1, KEAP1, and NRF2 levels were determined in the biochemistry laboratory using the ELISA technique.

Results

HO-1 levels were significantly lower in patients aged 3-12 years compared to controls aged 3-12, while KEAP1 and NRF2 levels were significantly higher (p=0.020, p<0.001, and p=0.017, respectively). No correlation was determined between ASD severity on the basis of total CARS scores and HO-1, KEAP1 or NRF2 (p>0.05).

Conclusion

This study suggests that oxidative stress is higher in children with ASD and that HO-1 levels are insufficient to achieve oxidative balance.

Blood homocysteine levels in children with autism spectrum disorder: An updated systematic review and meta-analysis

Results of studies on peripheral blood levels of homocysteine (Hcy) in children with autism spectrum disorder (ASD) are inconsistent, and conclusions from two previous meta-analyses on this subject published in 2012 are already outdated. Therefore, we conducted an updated systematic review and meta-analysis to quantitatively summarize the peripheral blood Hcy data in children with ASD compared with healthy controls (HC). We searched PubMed, EMBASE, PsycINFO, PsycARTICLES, Web of Science, and Cochrane Library databases from inception to September 2019 for eligible studies, with no language restriction. Using random-effects model, we computed summary statistics. Thirty-one studies (3304 participants including 1641 cases) were included. The pooled results showed that the peripheral blood Hcy levels were significantly elevated in children with ASD when compared to HC (Hedges's g = 0.56, 95% CI = 0.36 to 0.76, P < 0.001). By sensitivity analyses, we confirmed that our results were quite robust. Additionally, no publication bias was observed in this meta-analysis. In conclusion, our study support the association of increased circulating Hcy levels with ASD in children, and the involvement of Hcy in the occurrence of ASD. However, in view of the significant between-study heterogeneity, the conclusions should be interpreted cautiously and more investigation is required.

Association between peripheral blood levels of C-reactive protein and Autism Spectrum Disorder in children: A systematic review and meta-analysis

INTRODUCTION

In the past five years, a growing number of studies have tried to illustrate the association between the peripheral blood level of C-reactive protein (CRP) and Autism Spectrum Disorders (ASD). However, the results have been inconsistent. To assess whether abnormal CRP in peripheral blood was associated with ASD, we conducted a systematic review and meta-analysis.

METHODS

A systematic literature search was performed using the Embase, PubMed, Web of Knowledge, PsycINFO, and Cochrane databases through August 27, 2019. Reference lists were also checked by hand-searching. Clinical studies exploring CRP concentration in the peripheral blood of autistic children and healthy controls were included in our meta-analysis. Overlapping samples were excluded. We pooled obtained data using a fixed- or random-effect model based on a heterogeneity test with Comprehensive Meta-Analysis software and STATA software. Standardized mean differences were converted to Hedges' g statistic in order to obtain the effect size adjusted for sample size. Subgroup analyses, sensitivity analyses, meta-regression, and publication bias tests were also undertaken.

RESULTS

Nine studies with 592 ASD children and 604 healthy children were included in our meta-analysis. Significantly elevated CRP levels in peripheral blood were found in ASD children compared with healthy controls (Hedges' g = 0.527, 95% CI: 0.224-0.830, p = 0.001). Subgroup analyses based on sample types and ethnicity also showed similar results, except for the plasma subgroup. There was also a significant association between peripheral CRP concentration and ASD after removing the studies identified by Galbraith plots. The results of the sensitivity analysis revealed that no single study could reverse our results. Meta-regression analyses revealed that the gender of autistic children had a moderating effect on the outcome of the meta-analysis. In addition, no obvious publication bias was found in the meta-analysis.

CONCLUSIONS AND RELEVANCE

In our study, peripheral CRP levels were significantly elevated in autistic children compared with healthy children. These results may provide us some new insights about ASD.

Towards a Multivariate Biomarker-Based Diagnosis of Autism Spectrum Disorder: Review and Discussion of Recent Advancements

An ever-evolving understanding of autism spectrum disorder (ASD) pathophysiology necessitates that diagnostic standards also evolve from being observation-based to include quantifiable clinical measurements. The multisystem nature of ASD motivates the use of multivariate methods of statistical analysis over common univariate approaches for discovering clinical biomarkers relevant to this goal. In addition to characterization of important behavioral patterns for improving current diagnostic instruments, multivariate analyses to date have allowed for thorough investigation of neuroimaging-based, genetic, and metabolic abnormalities in individuals with ASD. This review highlights current research using multivariate statistical analyses to quantify the value of these behavioral and physiological markers for ASD diagnosis. A detailed discussion of a blood-based diagnostic test for ASD using specific metabolite concentrations is also provided. The advancement of ASD biomarker research promises to provide earlier and more accurate diagnoses of the disorder.

Serum levels of superoxide dismutases in patients with benign paroxysmal positional vertigo

Objective: To investigate the possible role of superoxide dismutases (SODs) in the development of benign paroxysmal positional vertigo (BPPV) and recurrence events in a 1-year follow-up study.

Methods: This was a prospective one-center study. A total of 204 patients with BPPV and 120 age-and sex matched healthy subjects were included. The levels of SOD between patients and control cases were compared. The levels of SOD between posterior semicircular canal (PSC) and horizontal semicircular canal (HSC) were also compared. In the 1-year follow-up, recurrence events were confirmed. The influence of SOD levels on BPPV and recurrent BPPV were performed by binary logistic regression analysis.

Results: The serum levels of SOD in patients with BPPV were lower than in those control cases (P<0.001). Levels of SOD did not differ in patients with PSC and HSC (P=0.42). As a categorical variable, for per interquartile range (IQR) increment of serum level of SOD, the unadjusted and adjusted risks of BPPV would be decreased by 72% (with the odds ratio [OR] of 0.28 [95% confidence interval (CI): 0.21–0.37], P<0.001) and 43% (0.57 [0.42–0.69], P<0.001), respectively. Recurrent attacks of BPPV were reported in 50 patients (24.5%). Patients with recurrent BPPV had lower levels of SOD than in patients without (P<0.001). For per IQR increment of serum level of SOD, the unadjusted and adjusted risks of BPPV would be decreased by 51% (with the OR of 0.49 [95% CI: 0.36–0.68], P<0.001) and 24% (0.76 [0.60–0.83], P<0.001), respectively.

Conclusion: Reduced serum levels of SOD were associated with higher risk of BPPV and BPPV recurrence events.

Fourier Transform Infrared Spectroscopy Based Complementary Diagnosis Tool for Autism Spectrum Disorder in Children and Adolescents

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that begins early in life and continues lifelong with strong personal and societal implications. It affects about 1%-2% of the children population in the world. The absence of auxiliary methods that can complement the clinical evaluation of ASD increases the probability of false identification of the disorder, especially in the case of very young children. In this study, analytical models for auxiliary diagnosis of ASD in children and adolescents, based on the analysis of patients' blood serum ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared) spectra, were developed. The models use chemometrics (either Principal Component Analysis (PCA) or Partial Least Squares Discriminant Analysis (PLS-DA)) methods, with the infrared spectra being the X-predictor variables. The two developed models exhibit excellent classification performance for samples of ASD individuals vs. healthy controls. Interestingly, the simplest, unsupervised PCA-based model results to have a global performance identical to the more demanding, supervised (PLS-DA)-based model. The developed PCA-based model thus appears as the more economical alternative one for use in the clinical environment. Hierarchical clustering analysis performed on the full set of samples was also successful in discriminating the two groups.

Dysregulated enzymatic antioxidant network in peripheral neutrophils and monocytes in children with autism

Autism spectrum disorder (ASD) is a neurodevelopmental disorder where immune cells play an important role. Oxidants and pro-inflammatory cytokines generated by innate immune cells have been implicated in the pathogenesis of ASD. Many previous reports have shown the role of various enzymatic antioxidants in the plasma/red blood cells of ASD subjects, however no study so far has evaluated them in peripheral immune cells of innate origin (neutrophils and monocytes) in ASD patients and typically developing control (TDC) children. With this background, our study explored the expression and activities of major enzymatic antioxidants such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR) in peripheral neutrophils and monocytes of TDC/ASD subjects. Our data show that expression and activity of SOD is increased in ASD subjects as compared to TDC children in neutrophils and monocytes. On the other hand, GPx/GR activity is either reduced/unaltered in neutrophils and monocytes of ASD subjects as compared to TDC children. Increased SOD expression is associated with upregulated expression of nitrotyrosine (a marker of oxidant damage) in both innate immune cells of ASD subjects. Our study suggests that despite adaptive antioxidant response, there is an increased oxidative burden in peripheral neutrophils and monocytes of ASD subjects. This suggests that dysregulated enzymatic antioxidant network in peripheral innate immune cells could play a significant role in the pathogenesis of autism.

Increased serum levels of macrophage migration inhibitory factor in autism spectrum disorders

OBJECTIVE

Macrophage migration inhibitory factor (MIF) has been suggested as a pivotal regulator of innate immunity and inflammatory. The aim of this study was to measure serum circulating levels of MIF in relation to the degree of the severity of autism spectrum disorders (ASD).

METHODS

One hundred and two Chinese children with ASD and same their age-sex matched typical development children were included. Concentrations of MIF were tested by Quantikine Human MIF Immunoassay. Serum levels of homocysteine (HCY), C-reactive protein (CRP) and serum Interleukin 6 (IL-6) were also tested. The influence of serum levels of MIF on ASD risk and ASD severity were performed by binary logistic regression analysis.

RESULTS

The serum levels of MIF in the children with ASD (24.7 ± 08.9 ng/ml) were significantly higher than those of control subjects (18.3 ± 5.5 ng/ml) (t = 6.134, P < 0.001). Levels of MIF increased with increasing severity of ASD as defined by the CARS score (P < 0.001). In multivariate model, MIF was associated with an increased risk of ASD (OR 1.11, 95% CI: 1.05-1.17; P < 0.001). MIF improved the combined model (HCY/CRP/IL-6) to predict ASD (P < 0.001). At admission, 68 children (66.7%) had a severe autism. In these children, the mean serum level of MIF was higher than in those children with mild to moderate autism (28.1 ± 8.5 ng/ml VS. 17.9 ± 4.7 ng/ml; t = 6.482, P < 0.001). In multivariate model, MIF was still associated with an increased risk of severe ASD (OR: 1.15, 95% CI: 1.04-1.19; P < 0.001). MIF improved the combined model (HCY/CRP/IL-6) to predict severe ASD (P < 0.001).

CONCLUSIONS

These results identify high serum MIF levels are associated with severity of ASD. Further study is warranted on the precise involvement of MIF in ASD, and the mechanism by which MIF contributes to ASD pathogenesis.

A certain role of SOD/CAT imbalance in pathogenesis of autism spectrum disorders

The real impact of reactive oxygen species, antioxidant enzymes, mitochondrial dysfunction and chronic inflammation on the development of autism spectrum disorders (ASD) remains unclear, and even controversial. In this study we compared the plasma levels of antioxidant enzymes and their cofactors, markers of oxidative damage, and the respiratory burst in peripheral blood polymorphonuclear leucocytes (PMNL) as surrogate marker of chronic inflammation obtained from 10 children (4-10 year old) who met DSM-5 criteria and their siblings. We demonstrated diminished superoxide dismutase (SOD) and enhanced catalase (CAT) activities resulting in a markedly decreased SOD/CAT ratio and enhanced carbonyl content in the plasma of ASD patients. A strong correlation was present between SOD and CAT activities in the control group, which was not noted in ASD patients. Moreover, in autistic patients, we observed negative correlation between SOD activity on one side, and carbonyl content in plasma, 8-Hydroxy-2-deoxyguanosin content in urine, and respiratory burst intensity in PMNL on the other side. At the same time, low SOD level in autistic children was positively correlated with the magnesium content in the packed RBCs, which might indicate the involvement of the mitochondrial MnSOD in ASD pathogenesis, and therefore the consequent partaking of mitochondrial dysfunction in the development of ASD. Altogether, these results indicate that decreased antioxidant capacity and increased oxidative stress in ASD patients may have functional consequence in terms of increased superoxide leakage, oxidative protein damage, chronic inflammatory response, and, finally, neuronal cell abnormal functioning or death.

Excitotoxicity in the pathogenesis of neurological and psychiatric disorders: Therapeutic implications

Neurological and psychiatric disorders are leading contributors to the global disease burden, having a serious impact on the quality of life of both patients and their relatives. Although the molecular events underlying these heterogeneous diseases remain poorly understood, some studies have raised the idea of common mechanisms involved. In excitotoxicity, there is an excessive activation of glutamate receptors by excitatory amino acids, leading to neuronal damage. Thus, the excessive release of glutamate can lead to a dysregulation of Ca²⁺ homeostasis, triggering the production of free radicals and oxidative stress, mitochondrial dysfunction and eventually cell death. Although there is a consensus in considering excitotoxicity as a hallmark in most neurodegenerative diseases, increasing evidence points to the relevant role of this pathological mechanism in other illnesses affecting the central nervous system. Consequently, antagonists of glutamate receptors are used in current treatments or in clinical trials in both neurological and psychiatric disorders. However, drugs modulating other aspects of the excitotoxic mechanism could be more beneficial. This review discusses how excitotoxicity is involved in the pathogenesis of different neurological and psychiatric disorders and the promising strategies targeting the excitotoxic insult.

Ultrahigh-yield synthesis of N-doped carbon nanodots that down-regulate ROS in zebrafish

Oxidative damage induced by accumulation of excessive reactive oxygen species (ROS) could result in increased chronic inflammation and thus ageing and age-related diseases. Carbonaceous nanodrugs hold great promise for ameliorating age-related diseases, and it is necessary to develop ultrahigh-yield synthesis of such nanodrugs. To improve the synthetic yield (less than 50%) of carbon nanodots (CNDs), the general choice is to screen precursors. However, no reliable concept for improving the yield has been explored over the past few decades. We are the first to propose the concept of using carbon-carbon double bonds to boost the synthetic yield and demonstrate record breaking ultrahigh-yield (85.9%) synthesis of N-doped CNDs. When the C[double bond, length as m-dash]C content increased from 14 to 56 mmol, the synthetic yield exhibited a 3.3-fold increase. Nitrogen elements are doped as pyridinic-like N and NH₂, where conjugated π-systems as electron donors and pyridinic-like structures would benefit the potential down-regulated effect for ROS. N-doped CNDs exhibit an outstanding protective effect against oxidative stress via inhibiting exogenous and endogenous ROS generation, where the ROS in zebrafish are significantly reduced by 68%. Hence the concept of carbon-carbon double bond-boosted ultrahigh-yield synthesis of N-doped CNDs provides a promising strategy to be employed for carbonaceous nanodrugs aiming at preventing and curing ageing and age-related diseases.

Impaired Redox Control in Autism Spectrum Disorders: Could It Be the X in GxE?

PURPOSE OF REVIEW

This review aims to provide a brief description of the complex etiology of autism spectrum disorders (ASD), with special emphasis on the recent findings of impaired redox control in ASD, and to suggest a possible model of oxidative stress-specific gene-environment interaction in this group of disorders.

RECENT FINDINGS

Recent findings point out to the significance of environmental, prenatal, and perinatal factors in ASD but, at the same time, are in favor of the potentially significant oxidative stress-specific gene-environment interaction in ASD. Available evidence suggests an association between both the identified environmental factors and genetic susceptibility related to the increased risk of ASD and the oxidative stress pathway. There might be a potentially significant specific gene-environment interaction in ASD, which is associated with oxidative stress. Revealing novel susceptibility genes (including those encoding for antioxidant enzymes), or environmental factors that might increase susceptibility to ASD in carriers of a specific genotype, might enable the stratification of individuals more prone to developing ASD and, eventually, the possibility of applying preventive therapeutic actions.

Behavioral regression in 2 patients with autism spectrum disorder and attention-deficit/hyperactivity disorder after oral surgery performed with a general anesthetic

BACKGROUND AND OVERVIEW

Routine dental care for people with autism spectrum disorders can be complex. There is little published on postoperative behavioral changes associated with use of general anesthetics in this population.

CASE DESCRIPTION

The authors describe postoperative behavioral changes in 2 patients with autism spectrum disorder and attention deficit hyperactivity disorder that the patients' caretakers described as regression. In both cases, behaviors representative of autism spectrum disorder and attention deficit hyperactivity disorder worsened after uncomplicated oral surgery after receipt of a general anesthetic in the operating room. In both cases, behavioral changes caused great difficulties for the patients and caretakers and were difficult to address.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

With little in the scientific literature, these 2 cases have a great importance for the dental care practitioner. Awareness must be raised so that further investigation can occur regarding this phenomenon.

Decreased total antioxidant capacity has a larger effect size than increased oxidant levels in urine in individuals with autism spectrum disorder

Oxidant/antioxidant imbalance may contribute to the pathophysiology of autism spectrum disorder (ASD). We assayed urinary levels of oxidative stress related biomarkers, hexanoyl-lysine (HEL), total antioxidant capacity (TAOC), the DNA methylation biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG), and plasma levels of superoxide dismutase (SOD), which is major antioxidant enzyme. We examined the relationship between these four biomarkers and social responsiveness in 20 individuals with ASD and in 11 healthy controls. The sex (ASD group, 7/13 vs. control group, 4/7) and age distributions (ASD group, 10.7 ± 5.0 years vs. control group, 14.7 ± 6.3 years) were not significantly different between the groups. Social responsiveness was assessed using the social responsiveness scale (SRS). We used standardized regression coefficients to measure the effect size. The ASD group exhibited significantly lower urinary TAOC levels and significantly elevated urinary HEL levels than the control group. Urinary 8-OHdG levels and plasma SOD levels were not significantly different between the groups. The ASD group showed significantly higher SRS scores than the control group. Plasma SOD levels correlated significantly with urinary TAOC levels. Standardized regression coefficients revealed that TAOC levels had a larger effect size than HEL levels in urine. This study firstly reveals that an imbalance between urinary HEL and TAOC levels in favor of urinary TAOC levels may contribute to impaired social responsiveness in individuals with ASD. Plasma SOD levels may also affect urinary TAOC levels.

Toll-like receptor 4 signaling is associated with upregulated NADPH oxidase expression in peripheral T cells of children with autism

Autism spectrum disorders (ASD) affect millions of children worldwide, and are characterized by impairment in social interaction and communication, and specific repetitive behavioral patterns. Growing evidence highlights a role of toll-like receptors (TLRs) in the pathogenesis of ASD. Specifically, TLR-4 activation has been shown to be associated with increased pro-inflammatory cytokines as well as autistic symptoms in offspring. NADPH oxidase (NOX-2) derived reactive oxygen species (ROS) have also been shown to play pathogenic role under inflammatory conditions. However, the role of TLR-4 in the regulation of NOX-2 derived ROS has not been explored in ASD, particularly in T cells. Therefore, this study explored TLR-4 and NOX-2 related signaling in peripheral T cells of ASD patients (n=35) and age-matched typically developing children (n=30). In this study, we find that ASD individuals have increased TLR-4 expression on T cells which is associated with increased NOX-2 expression and ROS generation as compared to typically developing children. Moreover, activation of TLR-4 on T cells by lipopolysaccharide (LPS) in vitro leads to enhanced generation of NOX-2 derived ROS via nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway. These data support a link between T cell TLR-4 activation and NOX-2/ROS upregulation in ASD patients. Our study has implications in the context of neuroinflammation observed in ASD patients as ROS may lead to amplification and perpetuation of inflammation both in the periphery and central nervous system. Our data also suggest that therapeutic targeting of TLR-4 signaling may lead to reduction in inflammation of ASD patients.

Serum levels of Glial fibrillary acidic protein in Chinese children with autism spectrum disorders

OBJECTIVE

Glial fibrillary acidic protein (GFAP) has been studied in many neurological diseases. The purpose of this study is to investigate the potential role of GFAP in Chinese children with autism spectrum disorders (ASD) by measuring serum circulating levels of GFAP and comparing them with age and gender-matched typical development children.

METHODS

A total of one hundred and fifty 2-6 years old Chinese children (75 confirmed autism cases and 75 their age-gender matched typical development children) participated in this study. Serum levels of GFAP were assayed with enzyme-linked immunosorbent assay methods, and severity of ASD was evaluated with the Childhood Autism Rating Scale (CARS) Score.

RESULTS

The results indicated that the mean serum GFAP level was significantly (P<0.001) higher in autistic children as compared to controls (1.71±0.53ng/ml vs. 0.99±0.25ng/ml). There was a significant positive association between serum GFAP levels and CARS scores (r [Pearson]=0.390, P=0.001). Based on the Receiver operating characteristic (ROC) curve, the optimal cut-off value of serum GFAP levels as an indicator for auxiliary diagnosis of autism was projected to be 1.28ng/ml which yielded a sensitivity of 77.3% and a specificity of 88.4%, the area under the curve was 0.895(95%CI, 0.844-0.947). Further, an increased risk of ASD was associated with GFAP levels >1.28ng/ml (adjusted OR 9.88, 95% CI: 3.32-17.82) in the multivariate logistic analysis model.

CONCLUSION

The data indicates that serum GFAP levels may be associated with severity of ASD among Chinese children, suggesting the hypothesis that increased serum levels of GFAP could be implicated in the pathophysiology of autism in Chinese children.

Lower maternal serum 25(OH) D in first trimester associated with higher autism risk in Chinese offspring

OBJECTIVE

The aim of this study was to examine the association between maternal serum vitamin D status in first trimester and risk of ASD at age 3-7years in the offspring.

METHODS

Using a case-control design, 68 children diagnosed with ASD and 68 sex and age matched typically-developing children were included. Archived maternal blood samples from the first trimester of pregnancy (11-13weeks gestational age) were identified for those participants. Maternal serum levels of 25 hydroxyvitamin D3 [25(OH) D], unmetabolized folic acid (FA), vitamin B12, homocysteine (HCY) and High Sensitivity C Reactive protein (CRP) were measured from those samples. We examined the associations between those factors in pregnancy and diagnosis of ASD with logistic regression using SPSS.

RESULTS

Mothers in autistic group had significantly lower maternal serum levels of 25(OH) D than in typically-developing group [19.2(IQR: 15.8-22.9)ng/ml vs. 24.3(19.3-27.3)ng/ml, P<0.001], with 55.9% and 29.4% being vitamin D deficient, respectively (P<0.001). Levels of 25(OH) D increased with decreasing severity of ASD as defined by the CARS score (r=-0.302, P<0.001). Maternal first trimester serum levels of 25(OH) D in the lower 3 quartiles (quartile 1, 2, 3) (compared to the highest quartile) was associated with increased odds of ASD diagnosis in offspring [OR (95% CI) Q1: 1.36(0.84-2.58, P=0.25); Q2: 2.68(1.44-4.29, P=0.006); Q3:3.99(2.58-7.12, P<0.001)].

CONCLUSIONS

Lower first trimester maternal serum levels of 25(OH) D were associated with increased risk of developing autism in offspring. If these findings are confirmed, this may present an opportunity for prenatal intervention to reduce the risk for ASD.

Reduced endogenous urinary total antioxidant power and its relation of plasma antioxidant activity of superoxide dismutase in individuals with autism spectrum disorder

Individuals with autism spectrum disorders (ASD) have impaired detoxification capacity. Investigating　the neurobiological bases of　impaired antioxidant capacity is thus a research priority in the pathophysiology of ASD.　We measured　the urinary levels of hexanoyl-lysine (HEL) which is a new oxidative stress　biomarker, total antioxidant power (TAP) and DNA methylation biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG), and the plasma levels of superoxide dismutase (SOD), which is a major antioxidant enzyme. We examined whether the urinary levels of these enzymes and biomarkers may be related to symptoms of social impairment in 20 individuals with ASD (meanage,11.1±5.2years) and 12 age- and gender-matched healthy controls (meanage,14.3±6.2years). Symptoms of social impairment were　assessed using the Social Responsiveness Scale (SRS). The dietary TAP of the fruit juice, chocolate, cookies, biscuits, jam and marmalade were significantly higher in the ASD group than in the control group, although the intake of nutrients was not significantly different between the groups. The urinary TAP levels were significantly lower in the ASD group than in the control group. There were no significantly differences in urinary HEL and 8-OHdG levels between the ASD and control groups. The SRS scores were significantly higher in the ASD group than in the control group. Stepwise regression analysis revealed that urinary TAP levels and plasma SOD levels can differences in the biomarkers and the SRS scores between the ASD group and the control group. The endogenous antioxidant capacity may be deficient without altered urinary HEL and 8-OHdG levels in individuals with ASD. The plasma SOD levels may be related to reduced endogenous antioxidant capacity.