Serum Cytokine and Growth Factor Levels in Children with Autism Spectrum Disorder

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.

Pathology and Astrocytes in Autism

A distinct pathology for autism spectrum disorder (ASD) remains elusive. Human and animal studies have focused on investigating the role of neurons in ASD. However, recent studies have hinted that glial cell pathology could be a characteristic of ASD. Astrocytes are the most abundant glial cell in the brain and play an important role in neuronal function, both during development and in adult. They regulate neuronal migration, dendritic and spine development, and control the concentration of neurotransmitters at the synaptic cleft. They are also responsible for synaptogenesis, synaptic development, and synaptic function. Therefore, any change in astrocyte number and/or function could contribute to the impairment of connectivity that has been reported in ASD. Data available to date is scarce but indicates that while the number of astrocytes is reduced, their state of activation and their GFAP expression is increased in ASD. Disruption of astrocyte function in ASD may affect proper neurotransmitter metabolism, synaptogenesis, and the state of brain inflammation. Astrocytes alterations are common to ASD and other neurodevelopmental disorders. Future studies about the role of astrocytes in ASD are required to better understand this disorder.

Serum cytokine levels in children with spectrum autism disorder: Differences in pro- and anti-inflammatory balance

BACKGROUND

Autism Spectrum Disorders (ASDs) is a developmental and neurological disorder that affects all aspects of social communication, with limited and stereotypical interest, and atypical responses to sensory stimuli. Diagnosis of ASD is currently phenotype based with no reliable laboratory test available to assist clinicians. Researches have shown that individuals with autism often exhibit dysfunction of cytokines.

METHODS

A total of 42 patients with ASD and 20 matched controls participants were recruited for the study. Diagnosis was conducted by medical specialists and based on the International Classification of Mental and Behavioral Disorders - ICD-10, DSM-5 and CARS sore. Whole blood samples were collected and serum IL's and chemokin levels were made using ELISA kits.

RESULTS

Results demonstrated that in comparison to the controls, the individuals with autism showed significantly higher concentration of IL-1β, IL-4, IL-6 and IL-13. We also demonstrated significant correlations between the levels of cytokines which implies the presence of an interactive network between them. The results of ROC analysis indicated the 4-factors (IL-1β, IL-4, IL-6 and IL-13) could be potential biomarkers in diagnosis of ASD.

CONCLUSIONS

In this study, serum levels of cytokine differed among children with ASD. However, the findings of this support the possibility of using an appropriate selection of serum cytokine for the diagnosis ASD and emphasize the need to standardize quantitative methods for serum analysis.

From bedside to bench and back: Translating ASD models

Autism spectrum disorders (ASD) represent a heterogeneous group of disorders defined by deficits in social interaction/communication and restricted interests, behaviors, or activities. Models of ASD, developed based on clinical data and observations, are used in basic science, the "bench," to better understand the pathophysiology of ASD and provide therapeutic options for patients in the clinic, the "bedside." Translational medicine creates a bridge between the bench and bedside that allows for clinical and basic science discoveries to challenge one another to improve the opportunities to bring novel therapies to patients. From the clinical side, biomarker work is expanding our understanding of possible mechanisms of ASD through measures of behavior, genetics, imaging modalities, and serum markers. These biomarkers could help to subclassify patients with ASD in order to better target treatments to a more homogeneous groups of patients most likely to respond to a candidate therapy. In turn, basic science has been responding to developments in clinical evaluation by improving bench models to mechanistically and phenotypically recapitulate the ASD phenotypes observed in clinic. While genetic models are identifying novel therapeutics targets at the bench, the clinical efforts are making progress by defining better outcome measures that are most representative of meaningful patient responses. In this review, we discuss some of these challenges in translational research in ASD and strategies for the bench and bedside to bridge the gap to achieve better benefits to patients.