Common targetable inflammatory pathways in brain transcriptome of autism spectrum disorders and Tourette syndrome

Prenatal Programming of Monocyte Chemotactic Protein-1 Signaling in Autism Susceptibility

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that involves functional and structural defects in selective central nervous system (CNS) regions, harming the individual capability to process and respond to external stimuli, including impaired verbal and non-verbal communications. Etiological causes of ASD have not been fully clarified; however, prenatal activation of the innate immune system by external stimuli might infiltrate peripheral immune cells into the fetal CNS and activate cytokine secretion by microglia and astrocytes. For instance, genomic and postmortem histological analysis has identified proinflammatory gene signatures, microglia-related expressed genes, and neuroinflammatory markers in the brain during ASD diagnosis. Active neuroinflammation might also occur during the developmental stage, promoting the establishment of a defective brain connectome and increasing susceptibility to ASD after birth. While still under investigation, we tested the hypothesis whether the monocyte chemoattractant protein-1 (MCP-1) signaling is prenatally programmed to favor peripheral immune cell infiltration and activate microglia into the fetal CNS, setting susceptibility to autism-like behavior. In this review, we will comprehensively provide the current understanding of the prenatal activation of MCP-1 signaling by external stimuli during the developmental stage as a new selective node to promote neuroinflammation, brain structural alterations, and behavioral defects associated to ASD diagnosis.

Symptoms compatible with long COVID in an Italian pediatric cohort of Tourette patients with and without SARS‑CoV‑2 infection: a short-term follow-up assessment

BACKGROUND

Tourette Syndrome (TS) is a childhood-onset neurodevelopmental disorder with a worldwide prevalence of about 0.3-1% of the population. During the pandemic caused by SARS-CoV-2 infection, the impact on the mental health of children and adolescents was very important. The persistence of symptoms in the post-acute phase of the disease has been termed Long COVID. The neuropsychiatric symptoms seem to be the most common impairment in children and adolescents with long COVID.

OBJECTIVES

Considering the impact of pandemic on mental health, in this study we analyzed the long-term effects of SARS-CoV-2 infection in children and adolescents affected by TS.

METHODS

We conducted an online questionnaire covering socio-demographic and clinical data among 158 patients affected by TS or chronic tic disorders (CTD), of which 78 participants reported a positive SARS-CoV-2 infection. Data were collected to investigate tic severity and both the comorbidities, as well as lockdown-related changes to daily life activities and, in case of infection of SARS-CoV-2, possible symptoms of acute infection and long COVID. Markers of systemic inflammation including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ferritin, iron, electrolytes, white blood cell counts, platelet cell counts levels, markers of liver, kidney and thyroid function were analyzed. First, all patients were screened with the Schedule for affective disorders and Schizophrenia for School age children-present and lifetime (Kiddie-SADS-PL) to rule out primary psychiatric disorders considered as criteria of exclusion. Then, all patients were clinically assessed at baseline (T0), and after three months (T1) through the administration of Yale Global Tic Severity Rating Scale (YGTSS), Multidimensional Anxiety Scale for Children (MASC), Child Depression Inventory (CDI) and Child Behavior Checklist (CBCL).

RESULTS

Among the cohort of TS patients that contracted SARS-CoV-2 infection, 84.6% (n = 66) experienced any acute symptoms, and long COVID symptoms occurred in 38.5% (n = 30). A worsening of clinical symptoms of tics and eventually associated comorbidities occurred in 34.6% (n = 27) of TS patients that contracted SARS-CoV-2 infection. TS patients with or without SARS-CoV-2 infection showed an increase in the severity of tics and also behavioral, depressive and anxious symptoms. Instead, this increase was more evident in patients who contracted the infection than in patients who did not contract it.

CONCLUSIONS

SARS-CoV-2 infection may have a role in the increase of tics and associated comorbidities in TS patients. Despite of these preliminary results, further investigations are necessary to improve knowledge about the acute and long-term impact of SARS-CoV-2 in TS patients.