The possible link between the elevated serum levels of neurokinin A and anti-ribosomal P protein antibodies in children with autism

Role of autoimmunity in Neuronal damage in children with Autism spectrum disorder

"Autism spectrum disorder (ASD) is complex neurodevelopmental disorder characterized by impairments in three core behavioral: social deficits, impaired communication, and repetitive behaviors." There is developing indication and emerging data that irregular autoimmune responses to the central nervous system may play a pathogenic role in patients with autism spectrum disorder." The aim of this review was to discuss the updated research carried out at Autism research and treatment center, King Saud University, Riyadh, Kingdom of Saudi Arabia particularly on the role of autoimmunity in Autism spectrum disorder. This review also present state of information available about the role of autoimmunity biomarkers involved in the neuronal damage of central nervous system in autistic children. The systematic literature search was carried out using Google Scholar, Science direct and PubMed databases on the role of autoimmunity in autism and reviewed all relevant articles published in peer reviewed journals by Autism research and treatment center, King Saud University, Riyadh, Kingdom of Saudi Arabia till April, 2022. We searched relevant articles using key words Autism spectrum disorder, Autoimmunity, Neuroinflamation and Central nervous system. This review revealed that plasma levels of autoimmunity related factors/ markers were altered in patients with autism. Significant change in blood markers in subjects with ASD may resulted in several years of decreased neutrotrophic support along with increasing impairment in relationship with down-regulated inflammation that may play a role in the ASD. Overall, the role of autoimmunity in ASD subjects with excess of anti-brain antibodies suggest that in some patients, autoantibodies that target the CNS may be pathological factor in neuronal growth in autistic children. Large cohort studies with well-defined and specially pheno typed autistic groups and matched healthy controls are required to examine the role of autoantibodies in the pathology of subjects with ASD.

Synthesis and evaluation of piperazinotriazoles. Discovery of a potent and orally bioavailable neurokinin-3 receptor inhibitor

The neurokinin-3 receptor (NK3R) is one of three receptors that recognize neurokinins. The finding that pharmacological blockade of neurokinin B (NKB) signaling with an oral NK3R antagonist can significantly improve hot flash symptoms independent of any hormonal effect fits strongly suggest that NK3R is a viable drug target and that drugs targeting this receptor could be novel pharmacotherapies. Currently no NK3R ligands have been approved for the treatment of human disorders. Herein, we designed and synthesized a series of novel imidazolepiperazine derivatives (16a-16x, 20a-20f, 29a-29m) and performed molecular docking to confirm the design, among which the target compound 16x exhibited promising inhibitory activity against NK3R (IC₅₀ = 430.60 nM) with excellent membrane permeability (Papp, A-B = 37.6 × 10^-6 cm/s, ER < 1) and oral bioavailability (F% = 93.6%). Our in vivo studies demonstrated that 16x was orally active, efficacious, and well-tolerated in ovariectomy (OVX) model to suppress blood luteinizing hormone levels, which suggests that 16x is a viable lead compound for further optimization and development.

Bee Pollen and Probiotics May Alter Brain Neuropeptide Levels in a Rodent Model of Autism Spectrum Disorders

Neuropeptides play a major role in maintaining normal brain development in children. Dysfunction of some specific neuropeptides can lead to autism spectrum disorders (ASD) in terms of social interaction and repetitive behavior, but the exact underlying etiological mechanisms are still not clear. In this study, we used an animal model of autism to investigate the role of bee pollen and probiotic in maintaining neuropeptide levels in the brain. We measured the Alpha-melanocyte-stimulating hormone (α-MSH), Beta-endorphin (β-End), neurotensin (NT), and substance P (SP) in brain homogenates of six studied groups of rats. Group I served as control, given only PBS for 30 days; Group II as an autistic model treated with 250 mg PPA/kg BW/day for 3 days after being given PBS for 27 days. Groups III-VI were denoted as intervention groups. G-III was treated with bee pollen (BP) 250 mg/kg body weight/day; G-IV with Lactobacillus paracaseii (LB) (109 CFU/mL) suspended in PBS; G-V with 0.2 g/kg body weight/day Protexin^®, a mixture of probiotics (MPB); and G-VI was transplanted with stool from normal animals (FT) for 27 days prior to the induction of PPA neurotoxicity on the last 3 days of study (days 28–30). The obtained data were analyzed through the use of principal component analysis (PCA), discriminant analysis (DA), hierarchical clustering, and receiver operating characteristic (ROC) curves as excellent statistical tools in the field of biomarkers. The obtained data revealed that brain levels of the four measured neuropeptides were significantly reduced in PPA-treated animals compared to healthy control animals. Moreover, the findings demonstrate the ameliorative effects of bee pollen as a prebiotic and of the pure or mixed probiotics. This study proves the protective effects of pre and probiotics against the neurotoxic effects of PPA presented as impaired levels of α-MSH, β-End, NT, and SP.

Up-regulated serum levels of TAM receptor tyrosine kinases in a group of Egyptian autistic children

TAM receptor family belongs to receptor tyrosine kinases (TAMRTKs). It includes three receptors; Tyro-3, Axl and Mer. TAMRTKs has a great role in resolution of inflammation due to their role in clearance of apoptotic cells by macrophages. Dysregulated TAM signaling pathways are associated with many autoimmune diseases and chronic inflammatory disorders. Autism may be an autoimmune disease in some patients. This work was the first study that investigated serum levels of the soluble ectodomain shed TAMRTKs in a group of autistic children. Serum levels of TAMRTKs were measured by ELISA in 30 autistic children aged between 3.5 and 11 years and 30 age and sex-matched healthy control children. Serum levels of TAMRTKs were significantly higher in autistic children than healthy control children (P < 0.001). Patients with severe autism had significantly higher serum levels of TAMRTKs than patients with mild to moderate autism (P < 0.01). In addition, there were significant positive correlations between scores of the Childhood Autism Rating Scale (CARS) and serum levels of TAMRTKs in autistic patients, (P < 0.01). In conclusions, serum levels of TAMRTKs were up-regulated in autistic children with significant positive correlations with the degree of the disease severity. This initial report requires further studies to investigate the relationship between TAMRTKs and autism.

Molecular Mechanisms of Aberrant Neuroplasticity in Autism Spectrum Disorders (Review)

This review presents the analysis and systematization of modern data on the molecular mechanisms of autism spectrum disorders (ASD) development. Polyetiology and the multifactorial nature of ASD have been proved. The attempt has been made to jointly review and systematize current hypotheses of ASD pathogenesis at the molecular level from the standpoint of aberrant brain plasticity. The mechanism of glutamate excitotoxicity formation, the effect of imbalance of neuroactive amino acids and their derivatives, neurotransmitters, and hormones on the ASD formation have been considered in detail. The strengths and weaknesses of the proposed hypotheses have been analyzed from the standpoint of evidence-based medicine. The conclusion has been drawn on the leading role of glutamate excitotoxicity as a biochemical mechanism of aberrant neuroplasticity accompanied by oxidative stress and mitochondrial dysfunction. The mechanism of aberrant neuroplasticity has also been traced at the critical moments of the nervous system development taking into account the influence of various factors of the internal and external environment. New approaches to searching for ASD molecular markers have been considered.

Plasma levels of nerve growth factor in Egyptian autistic children: Relation to hyperserotonemia and autoimmunity

Hyperserotonemia and brain-specific autoantibodies are detected in some autistic children. Nerve growth factor (NGF) stimulates the proliferation of B lymphocytes with production of antibodies and also increases mast cell serotonin release. This work was the first to investigate the relationship between plasma NGF and both hyperserotonemia and the frequency of serum anti-myelin basic protein (anti-MBP) auto-antibodies in 22 autistic children aged between 4 and 12 years and 22 healthy-matched controls. Levels of NGF, serotonin and anti-MBP were significantly higher in autistic children than healthy control children (P < 0.001). There was a significant positive correlation between NGF and serotonin levels in autistic patients (P < 0.01). In contrast, there was a non-significant correlation between NGF and anti-MBP levels (P > 0.05). In conclusions, serum NGF levels were elevated and significantly correlated to hyperserotonemia found in many autistic children.

Mercury as a hapten: A review of the role of toxicant-induced brain autoantibodies in autism and possible treatment considerations

BACKGROUND

Mercury has many direct and well-recognized neurotoxic effects. However, its immune effects causing secondary neurotoxicity are less well-recognized. Mercury exposure can induce immunologic changes in the brain indicative of autoimmune dysfunction, including the production of highly specific brain autoantibodies. Mercury, and in particular, Thimerosal, can combine with a larger carrier, such as an endogenous protein, thereby acting as a hapten, and this new molecule can then elicit the production of antibodies.

METHODS

A comprehensive search using PubMed and Google Scholar for original studies and reviews related to autism, mercury, autoantibodies, autoimmune dysfunction, and haptens was undertaken. All articles providing relevant information from 1985 to date were examined. Twenty-three studies were identified showing autoantibodies in the brains of individuals diagnosed with autism and all were included and discussed in this review.

RESULTS

Research shows mercury exposure can result in an autoimmune reaction that may be causal or contributory to autism, especially in children with a family history of autoimmunity. The autoimmune pathogenesis in autism is demonstrated by the presence of brain autoantibodies (neuroantibodies), which include autoantibodies to: (1) human neuronal progenitor cells; (2) myelin basic protein (MBP); (3) neuron-axon filament protein (NAFP); (4) brain endothelial cells; (5) serotonin receptors; (6) glial fibrillary acidic protein (GFAP); (7) brain derived neurotrophic factor (BDNF); (8) myelin associated glycoprotein (MAG); and (9) various brain proteins in the cerebellum, hypothalamus, prefrontal cortex, cingulate gyrus, caudate putamen, cerebral cortex and caudate nucleus.

CONCLUSION

Recent evidence suggests a relationship between mercury exposure and brain autoantibodies in individuals diagnosed with autism. Moreover, brain autoantibody levels in autism are found to correlate with both autism severity and blood mercury levels. Treatments to reduce mercury levels and/or brain autoantibody formation should be considered in autism.

Cortical signatures in behaviorally clustered autistic traits subgroups: a population-based study

Extensive heterogeneity in autism spectrum disorder (ASD) has hindered the characterization of consistent biomarkers, which has led to widespread negative results. Isolating homogenized subtypes could provide insight into underlying biological mechanisms and an overall better understanding of ASD. A total of 1093 participants from the population-based "Healthy Brain Network" cohort (Child Mind Institute in the New York City area, USA) were selected based on score availability in behaviors relevant to ASD, aged 6-18 and IQ >= 70. All participants underwent an unsupervised clustering analysis on behavioral dimensions to reveal subgroups with ASD traits, identified by the presence of social deficits. Analysis revealed three socially impaired ASD traits subgroups: (1) high in emotionally dysfunctional traits, (2) high in ADHD-like traits, and (3) high in anxiety and depressive symptoms. 527 subjects had good quality structural MRI T1 data. Site effects on cortical features were adjusted using the ComBat method. Neuroimaging analyses compared cortical thickness, gyrification, and surface area, and were controlled for age, gender, and IQ, and corrected for multiple comparisons. Structural neuroimaging analyses contrasting one combined heterogeneous ASD traits group against controls did not yield any significant differences. Unique cortical signatures, however, were observed within each of the three individual ASD traits subgroups versus controls. These observations provide evidence of ASD traits subtypes, and confirm the necessity of applying dimensional approaches to extract meaningful differences, thus reducing heterogeneity and paving the way to better understanding ASD traits.

Antigenic Targets of Patient and Maternal Autoantibodies in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder whose behavioral symptoms become apparent in early childhood. The underlying pathophysiological mechanisms are only partially understood and the clinical manifestations are heterogeneous in nature, which poses a major challenge for diagnosis, prognosis and intervention. In the last years, an important role of a dysregulated immune system in ASD has emerged, but the mechanisms connecting this to a disruption of brain development are still largely unknown. Although ASD is not considered as a typical autoimmune disease, self-reactive antibodies or autoantibodies against a wide variety of targets have been found in a subset of ASD patients. In addition, autoantibodies reactive to fetal brain proteins have also been described in the prenatal stage of neurodevelopment, where they can be transferred from the mother to the fetus by transplacental transport. In this review, we give an extensive overview of the antibodies described in ASD according to their target antigens, their different origins, and timing of exposure during neurodevelopment.

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

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

The levels of blood mercury and inflammatory-related neuropeptides in the serum are correlated in children with autism spectrum disorder

Tachykinins (substance P, neurokinin A, and neurokinin B) are pro-inflammatory neuropeptides that may play an important role in some autoimmune neuroinflammatory diseases, including autism spectrum disorder (ASD). Mercury (Hg) is a neurotoxicant, and potentially one of the main environmental triggers for ASD as it induces neuroinflammation with a subsequent release of neuropeptides. This is the first study to explore the potentially causal relationship between levels of serum neurokinin A and blood mercury (BHg) in children with ASD. Levels of serum neurokinin A and BHg were measured in 84 children with ASD, aged between 3 and 10 years, and 84 healthy-matched children. There was a positive linear relationship between the Childhood Autism Rating Scale (CARS) and both serum neurokinin A and BHg. ASD children had significantly higher levels of serum neurokinin A than healthy controls (P < 0.001). Increased levels of serum neurokinin A and BHg were respectively found in 54.8 % and 42.9 % of the two groups. There was significant and positive linear relationship between levels of serum neurokinin A and BHg in children with moderate and severe ASD, but not in healthy control children. It was found that 78.3 % of the ASD patients with increased serum levels of neurokinin A had elevated BHg levels (P < 0.001). Neuroinflammation, with increased levels of neurokinin A, is seen in some children with ASD, and may be caused by elevated BHg levels. Further research is recommended to determine the pathogenic role of increased levels of serum neurokinin A and BHg in ASD. The therapeutic role of tachykinin receptor antagonists, a potential new class of anti-inflammatory medications, and Hg chelators, should also be studied in ASD.

Association Between Atopic Dermatitis and Autism Spectrum Disorders: A Systematic Review

BACKGROUND

Atopic dermatitis (AD) is an allergic disorder caused by both immunological dysregulation and epidermal barrier defect. Several studies have investigated the association between AD and mental health disorders. Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental conditions characterized by impairments in social communication and restricted, stereotyped interests and behaviors. The concurrent increased prevalence of AD and ASD in the last decades has led many scientists to investigate the relationship between the two diseases.

OBJECTIVE

The aim of this systematic review was to examine the association between AD and ASD.

METHODS

A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed and ScienceDirect were searched up to March 2015 for all reports examining the association between ASD and AD. Descriptive statistics of the studies are reported.

RESULTS

The review included 18 studies assessing the association between ASD and AD. Of these studies, two focused on ASD in relation to AD alone, 14 discussed ASD in relation to both AD and other atopic disorders, and two evaluated AD in parents of children with ASD. Most of these studies found a positive association between the two disorders, although there were some studies going in the opposite direction. The entity of the association is somewhat inconsistent among the different studies given that the frequencies of AD in ASD compared with a control group ranged from 7 to 64.2%. In addition, odds ratios (ORs) or hazard ratios (HRs) gave different results as three studies found a weak association with an OR below 2 and a nonsignificant p value, and three other studies found a moderate or strong association with an OR ranging from 1.52 to 7.17 and a significant p value. When all atopic disorders were considered when evaluating the risk of ASD, the association was strong with an HR of 3.4 or an OR of 1.24 and p < 0.001.

CONCLUSIONS

Overall, the results of this systematic review seem to reveal an association between ASD and AD, suggesting that subjects with ASD have an increased risk of presenting with AD compared with typically developing controls, and vice versa. This association is supported by clinical/epidemiological aspects, shared genetic background and common immunological and autoimmune processes. However, the variability in study population and design, and the presence of other risk factors acting as confounding factors, sometimes contribute to inconsistent results. Further studies are needed to clarify the underlying pathophysiologic mechanism explaining the association between ASD and AD and to explore the causal association between the two conditions.

The possible link between elevated serum levels of epithelial cell-derived neutrophil-activating peptide-78 (ENA-78/CXCL5) and autoimmunity in autistic children

Background

In autoimmune disorders, the underlying pathogenic mechanism is the formation of antigen-antibody complexes which trigger an inflammatory response by inducing the infiltration of neutrophils. Epithelial cell-derived neutrophil-activating peptide-78 (ENA-78) is a chemokine that recruits and activates neutrophils, thus it could play a pathogenic role in inflammation and autoimmune disorders. Some autistic children have elevated levels of brain specific auto-antibodies. We are the first to evaluate serum expression of ENA-78 and its relation to antineuronal auto-antibodies in autistic children.

Methods

Serum ENA-78 and antineuronal auto-antibodies were measured by ELISA test in 62 autistic children aged between 4–11 years and 62 health-matched controls.

Results

Serum levels of ENA-78 were significantly higher in autistic children than healthy controls (P < 0.001). Increased serum levels of ENA-78 have been found in 69.35% of autistic patients. In addition, autistic children had significantly higher percent positivity of serum antineuronal auto-antibodies (64.5%) than healthy controls (6.45%), P < 0.001. There was a significant positive association between the positivity of serum antineuronal auto-antibodies and the elevated levels of serum ENA-78 (P < 0.001) in autistic children.

Conclusions

Serum levels of ENA-78 were elevated in autistic children and they were significantly associated with the increased levels of serum antineuronal auto-antibodies. However, these data should be treated with caution until further research is conducted to determine the pathogenic role of ENA-78 in autism and its relation to brain specific auto-antibodies that have been found in some autistic children. The possible therapeutic role of ENA-78 antagonist in autistic children should be also studied.

Systemic auto-antibodies in children with autism

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Altered cytokine and BDNF levels in autism spectrum disorder

The contribution of neuroimmune functioning and brain-derived neurotrophic factor (BDNF) to functional dysregulation in autism spectrum disorder was assessed in 29 patients under treatment in two specialized centers of Basilicata (Chiaromonte and Matera), Southern Italy, through analysis of serum levels of cytokines and BDNF. Elevated levels of the pro-inflammatory cytokine, including interleukin-1, interleukin-6, interleukin-12, interleukin-23, tumor necrosis factor-α and BDNF were observed, regardless of age and gender. Comparisons were made with age- and gender-related healthy controls. The present findings reinforce current notions regarding immunoexcitotoxic mechanisms contributing to the pathophysiology of autistic disorder.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

S100B is a calcium-binding protein that is produced primarily by astrocytes. Increased serum S100B protein levels reflect neurological damage. Autoimmunity may have a role in the pathogenesis of autism in some patients. Autoantibodies may cross the blood-brain barrier and combine with brain tissue antigens, forming immune complexes and resulting in neurological damage. We are the first to investigate the relationship between serum levels of S100B protein, a marker of neuronal damage, and antiribosomal P protein antibodies in autistic children.

METHODS

Serum S100B protein and antiribosomal P antibodies were measured in 64 autistic children in comparison to 46 matched healthy children.

RESULTS

Autistic children had significantly higher serum S100B protein levels than healthy controls (P < 0.001). Children with severe autism had significantly higher serum S100B protein than patients with mild to moderate autism (P = 0.01). Increased serum levels of antiribosomal P antibodies were found in 40.6% of autistic children. There were no significant correlations between serum levels of S100B protein and antiribosomal P antibodies (P = 0.29).

CONCLUSIONS

S100B protein levels were elevated in autistic children and significantly correlated to autistic severity. This may indicate the presence of an underlying neuropathological condition in autistic patients. Antiribosomal P antibodies may not be a possible contributing factor to the elevated serum levels of S100B protein in some autistic children. However, further research is warranted to investigate the possible link between serum S100B protein levels and other autoantibodies, which are possible indicators of autoimmunity to central nervous system in autism.