Analyses of peripheral blood dendritic cells and magnetic resonance spectroscopy support dysfunctional neuro-immune crosstalk in Tourette syndrome

Exploring the complex relationship between attention deficit hyperactivity disorder and the immune system: A bidirectional Mendelian randomization analysis

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition that can be accompanied by alterations in immune markers. However, the intricate nature of the association between ADHD and immune markers remains insufficiently elucidated. To explore the currently ambiguous causal relationship between ADHD and the immune system, we performed a bidirectional Mendelian randomization (MR) analysis of immune cell traits and ADHD under the randomized inverse variance weighting (IVW) method based on genome-wide association study (GWAS) summary data. We found ADHD increased the level of 3 immune cell traits including myeloid dendritic cells (β = 0.28, P = 0.008), monocyte (β = 0.25, P = 0.024) and granulocyte (β = 0.2, P = 0.042). We also identified 1 trait which belongs to B cell panel was a risk factor (odds ratio (OR) = 1.07, P = 0.001) for ADHD onset. Other 5 traits including CD14+ monocyte (OR = 0.98, P = 0.002), immature myeloid-derived suppressor cells (MDSC) (OR = 0.98, P = 0.003), monocyte MDSC (OR = 0.95, P = 0.005), CD33br HLA DR+ (OR = 0.97, P = 0.021) and basophil (OR = 0.96, P = 0.022) were protective factors for ADHD. Here we identified a range of causal relationships extending from ADHD to immune cell traits, underscoring the complex interaction patterns between ADHD and the immune system. Enhanced interventions for protective and risk factors may be beneficial in the prevention and treatment of ADHD.

Tourette syndrome: clinical features, pathophysiology, and treatment

Tourette syndrome is a chronic neurodevelopmental disorder characterised by motor and phonic tics that can substantially diminish the quality of life of affected individuals. Evaluating and treating Tourette syndrome is complex, in part due to the heterogeneity of symptoms and comorbidities between individuals. The underlying pathophysiology of Tourette syndrome is not fully understood, but recent research in the past 5 years has brought new insights into the genetic variations and the alterations in neurophysiology and brain networks contributing to its pathogenesis. Treatment options for Tourette syndrome are expanding with novel pharmacological therapies and increased use of deep brain stimulation for patients with symptoms that are refractory to pharmacological or behavioural treatments. Potential predictors of patient responses to therapies for Tourette syndrome, such as specific networks modulated during deep brain stimulation, can guide clinical decisions. Multicentre data sharing initiatives have enabled several advances in our understanding of the genetics and pathophysiology of Tourette syndrome and will be crucial for future large-scale research and in refining effective treatments.

Immunity and Gilles de la Tourette syndrome: A systematic review and meta-analysis of evidence for immune implications in Tourette syndrome

BACKGROUND AND PURPOSE

The neurobiology of Gilles de la Tourette syndrome (GTS) is known to involve corticostriatal loops possibly under genetic control. Less is known about possible environmental triggers of GTS. Specifically, immune-related events following possible environmental inducers have been evoked, but important controversies still exist. In this systematic review and meta-analysis, we looked for evidence in favor of such possibilities.

METHODS

We performed a systematic review and meta-analysis of all immunological data in PubMed.

RESULTS

We found large discrepancies concerning immune dysfunctions in GTS, and meta-analyzing cytokines data did not allow us to conclude there is an involvement of specific cytokines in GTS neurobiology. When looking specifically at pediatric autoimmune neuropsychiatric disorder associated with streptococcus/pediatric acute onset neuropsychiatric syndrome, we found some important evidence of a possible infectious involvement but in a limited number of studies. Our meta-analysis found an increased level of anti-streptolysin O antibodies in GTS patients, but the level of anti-DNase B antibodies was not increased.

CONCLUSIONS

Too many questions still exist to allow us to definitively reach the conclusion that there is an infectious and immunological etiology in GTS. Much work is still needed to elucidate the possible role of immunology in GTS neurobiology and to favor immunological treatment rather than classical treatment.