Various lines of evidence suggest that immune system dysregulation has a key role in autism spectrum disorder (ASD). Estes and McAllister review this evidence, covering genetic and maternal immune system-related risk factors, chronic immune system changes in individuals with ASD and in animal models, and potential pathophysiological mechanisms. Increasing evidence points to a central role for immune dysregulation in autism spectrum disorder (ASD). Several ASD risk genes encode components of the immune system and many maternal immune system-related risk factors — including autoimmunity, infection and fetal reactive antibodies — are associated with ASD. In addition, there is evidence of ongoing immune dysregulation in individuals with ASD and in animal models of this disorder. Recently, several molecular signalling pathways — including pathways downstream of cytokines, the receptor MET, major histocompatibility complex class I molecules, microglia and complement factors — have been identified that link immune activation to ASD phenotypes. Together, these findings indicate that the immune system is a point of convergence for multiple ASD-related genetic and environmental risk factors.

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Immune mediators in the brain and peripheral tissues in autism spectrum disorder

Objective We updated a prior systematic review of interventions for children (0–12 years) with autism spectrum disorder (ASD), focusing on recent studies of behavioral interventions. Data sources We searched the MEDLINE® (PubMed®), PsycInfo, and Educational Resources Information Clearinghouse (ERIC) databases as well as the reference lists of included studies and recent systematic reviews. We conducted the search in December 2013. Methods We included comparative studies (with treatment and comparison groups) of behavioral interventions with at least 10 participants with ASD in the update, and made our conclusions based on the cumulative comparative evidence across the original report and update. Two investigators independently screened studies against predetermined inclusion criteria and independently rated the quality of included studies. Results We included 65 unique studies comprising 48 randomized trials and 17 nonrandomized comparative studies (19 good, 39 fair, and 7 poor quality) published since the prior review. The quality of studies improved compared with that reported in the earlier review; however, our assessment of the strength of evidence (SOE), our confidence in the stability of effects of interventions in the face of future research, remains low for many intervention/outcome pairs. Early intervention based on high-intensity applied behavior analysis over extended timeframes was associated with improvement in cognitive functioning and language skills (moderate SOE for improvements in both outcomes) relative to community controls in some groups of young children. The magnitude of these effects varied across studies, potentially reflecting poorly understood modifying characteristics related to subgroups of children. Early intensive parent training programs modified parenting behaviors during interactions; however, data were more limited about their ability to improve developmental skills beyond language gains for some children (low SOE for positive effects on language). Social skills interventions varied in scope and intensity and showed some positive effects on social behaviors for older children in small studies (low SOE for positive effects on social skills). Studies of play/interaction-based approaches reported that joint attention interventions may demonstrate positive outcomes in preschool-age children with ASD when targeting joint attention skills (moderate SOE); data on the effects of such interventions in other areas were limited (low SOE for positive effects on play skills, language, social skills). Studies examining the effects of cognitive behavioral therapy on anxiety reported positive results in older children with IQs ≥70 (high SOE for improvements in anxiety in this population). Smaller short-term studies of other interventions reported some improvements in areas such as sleep and communication, but data were too sparse to assess their overall effectiveness. Conclusions A growing evidence base suggests that behavioral interventions can be associated with positive outcomes for children with ASD. Despite improvements in the quality of the included literature, a need remains for studies of interventions across settings and continued improvements in methodologic rigor. Substantial scientific advances are needed to enhance our understanding of which interventions are most effective for specific children with ASD and to isolate elements or components of interventions most associated with effects.

Therapies for Children With Autism Spectrum Disorder: Behavioral Interventions Update

Autism spectrum disorders (ASD) are characterized by social communication deficits, cognitive rigidity, and repetitive stereotyped behaviors. Mesenchymal stem cells (MSC) have a paracrine regenerative effect, and were speculated to be a potential therapy for ASD. The BTBR inbred mouse strain is a commonly used model of ASD as it demonstrates robust behavioral deficits consistent with the diagnostic criteria for ASD. BTBR mice also exhibit decreased brain-derived neurotrophic factor (BDNF) signaling and reduced hippocampal neurogenesis. In the current study, we evaluated the behavioral and molecular effects of intracerebroventricular MSC transplantation in BTBR mice. Transplantation of MSC resulted in a reduction of stereotypical behaviors, a decrease in cognitive rigidity and an improvement in social behavior. Tissue analysis revealed elevated BDNF protein levels in the hippocampus accompanied by increased hippocampal neurogenesis in the MSC-transplanted mice compared with sham treated mice. This might indicate a possible mechanism underpinning the behavioral improvement. Our study suggests a novel therapeutic approach which may be translatable to ASD patients in the future.

Mesenchymal Stem Cell Transplantation Promotes Neurogenesis and Ameliorates Autism Related Behaviors in BTBR Mice.

A systematic review of molecular imaging (PET and SPECT) in autism spectrum disorder: current state and future research opportunities

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

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

Cellular therapy is an emerging therapeutic modality with a great potential for the treatment of autism. Recent findings show that the major underlying pathogenetic mechanisms of autism are hypoperfusion and immune alterations in the brain. So conceptually, cellular therapy which facilitates counteractive processes of improving perfusion by angiogenesis and balancing inflammation by immune regulation would exhibit beneficial clinical effects in patients with autism. This is an open label proof of concept study of autologous bone marrow mononuclear cells (BMMNCs) intrathecal transplantation in 32 patients with autism followed by multidisciplinary therapies. All patients were followed up for 26 months (mean 12.7). Outcome measures used were ISAA, CGI, and FIM/Wee-FIM scales. Positron Emission Tomography-Computed Tomography (PET-CT) scan recorded objective changes. Out of 32 patients, a total of 29 (91%) patients improved on total ISAA scores and 20 patients (62%) showed decreased severity on CGI-I. The difference between pre- and postscores was statistically significant (P < 0.001) on Wilcoxon matched-pairs signed rank test. On CGI-II 96% of patients showed global improvement. The efficacy was measured on CGI-III efficacy index. Few adverse events including seizures in three patients were controlled with medications. The encouraging results of this leading clinical study provide future directions for application of cellular therapy in autism.

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Autologous Bone Marrow Mononuclear Cell Therapy for Autism: An Open Label Proof of Concept Study

Cell therapy offers a promising premise in alleviating complex neurological disorders. Autologous bone marrow mononuclear cells (BMMNCs) have been used in many studies and have been documented to have a safe and ethical profile. These cells have shown angiogenetic and immunomodulatory properties in addition to other neuroprotective effects. Precisely, these may serve to address a disorder at a neurophysiological level and thus, hold gratifying results in autism. The literature suggests hypoperfusion and immune alteration as major underlying pathogenetic mechanisms in autism. Herewith, we present a case of autism treated with intrathecal administration of autologous BMMNCs. Results were documented objectively on Indian Scale for Assessment of Autism (ISAA), Childhood Autism Rating Scale (CARS), Clinical Global Impression (CGI) scores and positron emission tomography computerized tomography (PET-CT) scan. On regular follow-up assessment of the patient at 3 mo, at 6 mo (pre 2nd dose) and at 9 mo (i.e., 3 mo post 2nd dose), significant clinical improvement was noted in social relationship, communication and behavior. On the outcome measure, his ISAA score improved from 132 (moderate autism) to 103 (mild autism). On comparison of the PET-CT scan, changes in metabolism correlated with the clinical improvements. On the CGI scores, he showed improvement in all the three domains, with a decrease in the severity of illness and with partial remission of symptoms. This case provides a useful insight into the clinical effects of autologous BMMNCs in autism and guides us to plan future studies and offers a promising premise in alleviating complex neurological disorders.

Mrudula Kali

Papers

Autologous Bone Marrow Mononuclear Cell Therapy for Autism: An Open Label Proof of Concept Study

Cell therapy effects portrayed on positron emission tomography of the brain serve as a new dimension for autism