Pediatric acute-onset neuropsychiatric syndrome (PANS) features a heterogeneous constellation of acute obsessive-compulsive disorder (OCD), eating restriction, cognitive, behavioral and/or affective symptoms, often followed by a chronic course with cognitive deterioration. An immune-mediated etiology is advocated in which the CNS is hit by different pathogen-driven (auto)immune responses. This narrative review focused on recent clinical (ie, diagnostic criteria, pre-existing neurodevelopmental disorders, neuroimaging) and pathophysiological (ie, CSF, serum, genetic and autoimmune findings) aspects of PANS. We also summarized recent points to facilitate practitioners with the disease management. Relevant literature was obtained from PubMed database which included only English-written, full-text clinical studies, case reports, and reviews. Among a total of 1005 articles, 205 were pertinent to study inclusion. Expert opinions are converging on PANS as the effect of post-infectious events or stressors leading to “brain inflammation”, as it is well-established for anti-neuronal psychosis. Interestingly, differentiating PANS from either autoimmune encephalitides and Sydenham’s chorea or from alleged “pure” psychiatric disorders (OCD, tics, Tourette’s syndrome), reveals several overlaps and more analogies than differences. Our review highlights the need for a comprehensive algorithm to help both patients during their acute distressing phase and physicians during their treatment decision. A full agreement on the hierarchy of each therapeutical intervention is missing owing to the limited number of randomized controlled trials. The current approach to PANS treatment emphasizes immunomodulation/anti-inflammatory treatments in association with both psychotropic and cognitive-behavioral therapies, while antibiotics are suggested when an active bacterial infection is established. A dimensional view, taking into account the multifactorial origin of psychiatric disorders, should suggest neuro-inflammation as a possible shared substrate of different psychiatric phenotypes. Hence, PANS and PANS-related disorders should be considered as a conceptual framework describing the etiological and phenotypical complexity of many psychiatric disorders.

Introduction: Our single-center case–control study aimed to evaluate the unclear glymphatic system alteration in autism spectrum disorder (ASD) through an innovative neuroimaging tool which allows to segment and quantify perivascular spaces in the white matter (WM-PVS) with filtering of non-structured noise and increase of the contrast-ratio between perivascular spaces and the surrounding parenchyma.Methods: Briefly, files of 65 ASD and 71 control patients were studied. We considered: ASD type, diagnosis and severity level and comorbidities (i.e., intellectual disability, attention-deficit hyperactivity disorder, epilepsy, sleep disturbances). We also examined diagnoses other than ASD and their associated comorbidities in the control group.Results: When males and females with ASD are included together, WM-PVS grade and WM-PVS volume do not significantly differ between the ASD group and the control group overall. We found, instead, that WM-PVS volume is significantly associated with male sex: males had higher WM-PVS volume compared to females (p = 0.01). WM-PVS dilation is also non-significantly associated with ASD severity and younger age (< 4 years). In ASD patients, higher WM-PVS volume was related with insomnia whereas no relation was found with epilepsy or IQ.Discussion: We concluded that WM-PVS dilation can be a neuroimaging feature of male ASD patients, particularly the youngest and most severe ones, which may rely on male-specific risk factors acting early during neurodevelopment, such as a transient excess of extra-axial CSF volume. Our findings can corroborate the well-known strong male epidemiological preponderance of autism worldwide.

Background: Heterogeneous mental health outcomes during the COVID-19 pandemic are documented in the general population. Such heterogeneity has not been systematically assessed in youth with autism spectrum disorder (ASD) and related neurodevelopmental disorders (NDD). To identify distinct patterns of the pandemic impact and their predictors in ASD/NDD youth, we focused on pandemic-related changes in symptoms and access to services. Methods: Using a naturalistic observational design, we assessed parent responses on the Coronavirus Health and Impact Survey Initiative (CRISIS) Adapted For Autism and Related neurodevelopmental conditions (AFAR). Cross-sectional AFAR data were aggregated across 14 European and North American sites yielding a clinically well-characterized sample of N = 1275 individuals with ASD/NDD (age = 11.0 ± 3.6 years; n females = 277). To identify subgroups with differential outcomes, we applied hierarchical clustering across eleven variables measuring changes in symptoms and access to services. Then, random forest classification assessed the importance of socio-demographics, pre-pandemic service rates, clinical severity of ASD-associated symptoms, and COVID-19 pandemic experiences/environments in predicting the outcome subgroups. Results: Clustering revealed four subgroups. One subgroup—broad symptom worsening only (20%)—included youth with worsening across a range of symptoms but with service disruptions similar to the average of the aggregate sample. The other three subgroups were, relatively, clinically stable but differed in service access: primarily modified services (23%), primarily lost services (6%), and average services/symptom changes (53%). Distinct combinations of a set of pre-pandemic services, pandemic environment (e.g., COVID-19 new cases, restrictions), experiences (e.g., COVID-19 Worries), and age predicted each outcome subgroup. Limitations: Notable limitations of the study are its cross-sectional nature and focus on the first six months of the pandemic. Conclusions: Concomitantly assessing variation in changes of symptoms and service access during the first phase of the pandemic revealed differential outcome profiles in ASD/NDD youth. Subgroups were characterized by distinct prediction patterns across a set of pre- and pandemic-related experiences/contexts. Results may inform recovery efforts and preparedness in future crises; they also underscore the critical value of international data-sharing and collaborations to address the needs of those most vulnerable in times of crisis.

Autism spectrum disorders (ASD) are characterized by a wide spectrum of clinical, behavioral, and cognitive manifestations. It is, therefore, crucial to investigate possible biomarkers associated with specific ASD phenotypes. Ample literature suggests a possible role for vitamin D (VD) in influencing ASD clinical phenotypes. We analyzed three vitamin D binding protein gene (DBP) functional polymorphisms (rs2282679, rs7041, and rs4588), which are involved in the modulation of vitamin D serum concentration in 309 ASD children and 831 healthy controls. Frequency comparisons of single nucleotide polymorphisms (SNPs) alleles, genotypes, and GC isoforms (GC1f, G1s, and GC2)—generated by the combination of rs7041 and rs4588 alleles—were correlated with ASD diagnostic, behavioral, and functioning scales. The GC1f isoform was significantly more frequent in ASD compared with controls (18.6% vs. 14.5% pc = 0.02). Significantly higher scores for item 15 of the Childhood Autism Rating Scale (CARS) and lower ones for the Children’s Global Assessment Scale (CGAS) functioning scales were seen in ASD carrying the GC1f isoform. In GC phenotype analysis, a gradient of severity for overall CARS scores and CARS item 15 was observed, with scores decreasing according to the presence of GC1f-GC1f > GC1f-GC1s > GC1s-GC1s > GC1f-GC2 > GC2-GC2 isoforms. Similarly, lower CGAS scores were seen in carriers of the GC1f-GC1f isoform, whereas higher scores were present in those carrying GC2-GC2 (p = 0.028). This is the first study to evaluate possible relationships between GC variants and the different aspects of ASD in Italian ASD children. Results, although needing to be validated in ampler cohorts, suggest that the GC1f isoform could be a marker of severity in ASD that may be useful in establishing the intensity of therapeutic and rehabilitative protocols.

ASD is a neurodevelopmental disorder of unknown aetiology but with a known contribution of pathogenic immune-mediated mechanisms. HERVs are associated with several neuropsychiatric diseases, including ASD. We studied anti-HERV-W, -K and -H-env immune profiles in ASD children to analyse differences between their respective mothers and child/mother control pairs and possible correlations to ASD severity and loss of adaptive abilities. Of the 84 studied individuals, 42 children (23 ASD and 19 neurotypical) and their paired mothers underwent clinical and neuropsychological evaluations. ASD severity was analysed with standardised tests. Adaptive functioning was studied with ABAS-II and GAC index. Plasma anti-env responses of HERV-K, -H and -W were tested with indirect ELISA. ASD and neurotypical children did not differ in age, gender, comorbidities and anti-HERV responses. In children with ASD, anti-HERV levels were not correlated to ASD severity, while a significant inverse correlation was found between anti-HERV-W-248-262 levels and adaptive/social abilities. Upregulation of anti-HERV-W response correlates to dysfunctional social and adaptive competences in ASD but not in controls, suggesting anti-HERV response plays a role in the appearance of peculiar ASD symptoms.

Increasing evidence indicates that human endogenous retroviruses (HERVs) are important to human health and are an underexplored component of many diseases. Certain HERV families show unique expression patterns and immune responses in autism spectrum disorder (ASD) patients compared to healthy controls, suggesting their potential as biomarkers. Despite these interesting findings, the role of HERVs in ASD needs to be further investigated. In this review, we discuss recent advances in genetic research on ASD, with a particular emphasis on the implications of HERVs on neurodevelopment and future genomic initiatives aimed at discovering ASD-related genes through Artificial Intelligence. Given their pro-inflammatory and autoimmune characteristics, the existing literature suggests that HERVs may contribute to the onset or worsening of ASD in individuals with a genetic predisposition. Therefore, we propose that investigating their fundamental properties could not only improve existing therapies but also pave the way for new therapeutic strategies.