The association between systemic autoimmune disorders and epilepsy and its clinical implications

Potential causal association of diabetes mellitus and blood glucose related indexes with the onset of epilepsy: a two-sample Mendelian randomization study

Aim

Diabetes mellitus (DM) may promote the occurrence of epilepsy through mechanisms, such as inflammation, immune imbalance, and cerebrovascular injury, caused by metabolic abnormalities. However, evidence for the effects of DM and blood glucose (BG) on the risk of epilepsy is limited. Herein, this study used the Mendelian randomization (MR) method to investigate the potential causal associations of DM and BG-related indexes with epilepsy.

Methods

In this two-sample MR study, summary statistics data of the genome-wide association studies (GWASs) on exposures, including type 1 diabetes mellitus (T1DM), T2DM, fasting glucose, and glycated hemoglobin (HbAlc), were extracted from the MRC-Integrative Epidemiology Unit (MRC-IEU). The GWAS data on study outcomes, including epilepsy, focal epilepsy, and generalized epilepsy, were obtained from the FinnGen consortium. MR-Egger regression was used to examine horizontal pleiotropism of instrumental variables (IVs), and Cochran's Q statistics was used to quantify the heterogeneity. MR analysis methods including inverse variance weighted (IVW) tests, weighted median, and MR-Egger were utilized to investigate the causal associations between DM and BG-related indexes with epilepsy. The evaluation indexes were odds ratios (ORs) and 95% confidence intervals (CIs). Reverse causal association analyses were also performed. In addition, IVW-radial and leave-one-out tests were utilized for sensitivity analyses.

Results

IVW estimates suggested that T1DM has potential causal associations with epilepsy (OR = 1.057, 95% CI: 1.031-1.084) and generalized epilepsy (OR = 1.066, 95% CI: 1.018-1.116). No significant reverse causal associations of T1DM with epilepsy or generalized epilepsy were found (all P > 0.05). In addition, sensitivity analysis results identified no outlier, indicating that the associations of T1DM with epilepsy and generalized epilepsy were relatively robust.

Conclusion

Patients with T1DM had a potential risk of developing epilepsy, and prompt treatment of DM and dynamic monitoring may be beneficial to prevent epilepsy in this high-risk population. However, the causal associations of DM and BG with epilepsy may warrant further verification.

Hippocampal sclerosis is associated with celiac disease type immunity in patients with drug-resistant temporal lobe epilepsy

BACKGROUND

A prior small-scale single center study suggested an association between celiac disease (CD)-type immunity and refractory temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS). The present study addresses this putative association in a large, well-characterized group of drug-resistant epilepsy (DRE) patients. These patients were grouped based on the spectrum of CD and gluten sensitivity-associated antibodies.

METHODS

In this cross-sectional study, 253 consecutive adult epilepsy patients (135 females, 118 males; age 16-76 years) were categorized into three groups: (i) CD-positive group with either prior diagnosis of CD or CD-specific TG2/EmA antibodies, (ii) AGA-positive group with antigliadin antibodies (AGA) but without CD, and (iii) CD/AGA-negative group without any gluten sensitivity-associated antibodies or CD. Clinical and immunological findings were then compared among the groups.

RESULTS

TLE with HS was more common in the CD-positive group compared to CD/AGA-negative group (31.8% versus 11.9%, P = 0.019). Autoimmune disorders were more common in the AGA-positive group than in the CD/AGA-negative group (P = 0.025). Considering HS lateralization; left lateralization was more common in CD-positive group compared to CD/AGA-negative group (71.4% versus 25%, P = 0.030). TG6 seropositivity did not differ among the groups (P > 0.05).

CONCLUSIONS

This study provides further evidence linking TLE with HS and CD-type autoimmunity suggesting that CD-type immune response to gluten can be one potential mechanism as a disease modifier leading to DRE and HS. Understanding these immunological factors is imperative for developing immunomodulatory or dietary treatments for DRE potentially preventing HS progression.

PDCD4 silencing alleviates KA‑induced neurotoxicity of HT22 cells by inhibiting endoplasmic reticulum stress via blocking the MAPK/NF‑κB signaling pathway

Human programmed cell death 4 (PDCD4) has been reported to participate in multiple neurological diseases. However, the role of PDCD4 in epilepsy, as well as its underlying mechanism, remains unclear. To induce excitotoxicity, 100 µM kainic acid (KA) was applied for the stimulation of HT22 cells for 12 h. Initially, the mRNA and protein expression levels of PDCD4 were evaluated using reverse transcription-quantitative PCR and western blotting. A lactate dehydrogenase assay was performed to detect cell injury. Cell apoptosis was assessed using flow cytometry and western blotting was performed to determine the expression levels of apoptosis-related proteins. Oxidative stress was detected using dichlorodihydrofluorescein diacetate staining, and malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) assay kits. Furthermore, the expression levels of MAPK/NF-κB signaling-related proteins and endoplasmic reticulum (ER) stress-related proteins C/EBP homologous protein, glucose-regulated protein 78, activating transcription factor 4 and phosphorylated-eukaryotic initiation factor-2α were assessed by western blotting. It was revealed that PDCD4 expression was markedly elevated in KA-induced HT22 cells, whereas PDCD4 silencing alleviated KA-induced neurotoxicity of HT22 cells by alleviating cell injury and inhibiting apoptosis. In addition, PDCD4 silencing reduced the levels of reactive oxygen species and MDA, but elevated those of SOD and GSH-Px. PDCD4 silencing also suppressed ER stress by blocking the MAPK/NF-κB signaling pathway. By contrast, the MAPK agonist phorbol myristate acetate reversed the effects of PDCD4 silencing on KA-induced neurotoxicity and oxidative stress in HT22 cells. In conclusion, PDCD4 silencing alleviated KA-induced neurotoxicity and oxidative stress in HT22 cells by suppressing ER stress through the inhibition of the MAPK/NF-κB signaling pathway, which may provide novel insights into the treatment of epilepsy.

Improving Early Recognition of Treatment-Responsive Causes of Rapidly Progressive Dementia: The STAM3 P Score

OBJECTIVE

To improve the timely recognition of patients with treatment-responsive causes of rapidly progressive dementia (RPD).

METHODS

A total of 226 adult patients with suspected RPD were enrolled in a prospective observational study and followed for up to 2 years. Diseases associated with RPD were characterized as potentially treatment-responsive or non-responsive, referencing clinical literature. Disease progression was measured using Clinical Dementia Rating® Sum-of-Box scores. Clinical and paraclinical features associated with treatment responsiveness were assessed using multivariable logistic regression. Findings informed the development of a clinical criterion optimized to recognize patients with potentially treatment-responsive causes of RPD early in the diagnostic evaluation.

RESULTS

A total of 155 patients met defined RPD criteria, of whom 86 patients (55.5%) had potentially treatment-responsive causes. The median (range) age-at-symptom onset in patients with RPD was 68.9 years (range 22.0-90.7 years), with a similar number of men and women. Seizures, tumor (disease-associated), magnetic resonance imaging suggestive of autoimmune encephalitis, mania, movement abnormalities, and pleocytosis (≥10 cells/mm3 ) in cerebrospinal fluid at presentation were independently associated with treatment-responsive causes of RPD after controlling for age and sex. Those features at presentation, as well as age-at-symptom onset <50 years (ie, STAM3 P), captured 82 of 86 (95.3%) cases of treatment-responsive RPD. The presence of ≥3 STAM3 P features had a positive predictive value of 100%.

INTERPRETATION

Selected features at presentation reliably identified patients with potentially treatment-responsive causes of RPD. Adaptation of the STAM3 P screening score in clinical practice may minimize diagnostic delays and missed opportunities for treatment in patients with suspected RPD. ANN NEUROL 2024;95:237-248.

Identification and verification of ferroptosis-related genes in the pathology of epilepsy: insights from CIBERSORT algorithm analysis

Background

Epilepsy is a neurological disorder characterized by recurrent seizures. A mechanism of cell death regulation, known as ferroptosis, which involves iron-dependent lipid peroxidation, has been implicated in various diseases, including epilepsy.

Objective

This study aimed to provide a comprehensive understanding of the relationship between ferroptosis and epilepsy through bioinformatics analysis. By identifying key genes, pathways, and potential therapeutic targets, we aimed to shed light on the underlying mechanisms involved in the pathogenesis of epilepsy.

Materials and methods

We conducted a comprehensive analysis by screening gene expression data from the Gene Expression Omnibus (GEO) database and identified the differentially expressed genes (DEGs) related to ferroptosis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to gain insights into the biological processes and pathways involved. Moreover, we constructed a protein-protein interaction (PPI) network to identify hub genes, which was further validated using the receiver operating characteristic (ROC) curve analysis. To explore the relationship between immune infiltration and genes, we employed the CIBERSORT algorithm. Furthermore, we visualized four distinct interaction networks-mRNA-miRNA, mRNA-transcription factor, mRNA-drug, and mRNA-compound-to investigate potential regulatory mechanisms.

Results

In this study, we identified a total of 33 differentially expressed genes (FDEGs) associated with epilepsy and presented them using a Venn diagram. Enrichment analysis revealed significant enrichment in the pathways related to reactive oxygen species, secondary lysosomes, and ubiquitin protein ligase binding. Furthermore, GSVA enrichment analysis highlighted significant differences between epilepsy and control groups in terms of the generation of precursor metabolites and energy, chaperone complex, and antioxidant activity in Gene Ontology (GO) analysis. Furthermore, during the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, we observed differential expression in pathways associated with amyotrophic lateral sclerosis (ALS) and acute myeloid leukemia (AML) between the two groups. To identify hub genes, we constructed a protein-protein interaction (PPI) network using 30 FDEGs and utilized algorithms. This analysis led to the identification of three hub genes, namely, HIF1A, TLR4, and CASP8. The application of the CIBERSORT algorithm allowed us to explore the immune infiltration patterns between epilepsy and control groups. We found that CD4-naïve T cells, gamma delta T cells, M1 macrophages, and neutrophils exhibited higher expression in the control group than in the epilepsy group.

Conclusion

This study identified three FDEGs and analyzed the immune cells in epilepsy. These findings pave the way for future research and the development of innovative therapeutic strategies for epilepsy.

The evolution of antiseizure medication therapy selection in adults: Is artificial intelligence -assisted antiseizure medication selection ready for prime time?

Antiseizure medications (ASMs) are the mainstay of symptomatic epilepsy treatment. The primary goal of pharmacotherapy with ASMs in epilepsy is to achieve complete seizure remission while minimizing therapy-related adverse events. Over the years, more ASMs have been introduced, with approximately 30 now in everyday use. With such a wide variety, much guidance is needed in choosing ASMs for initial therapy, subsequent replacement monotherapy, or adjunctive therapy. The specific ASMs are typically tailored by the patient's related factors, including epilepsy syndrome, age, sex, comorbidities, and ASM characteristics, including the spectrum of efficacy, pharmacokinetic properties, safety, and tolerability. Weighing these key clinical variables requires experience and expertise that may be limited. Furthermore, with this approach, patients may endure multiple trials of ineffective treatments before the most appropriate ASM is found. A more reliable way to predict response to different ASMs is needed so that the most effective and tolerated ASM can be selected. Soon, alternative approaches, such as deep machine learning (ML), could aid the individualized selection of the first and subsequent ASMs. The recognition of epilepsy as a network disorder and the integration of personalized epilepsy networks in future ML platforms can also facilitate the prediction of ASM response. Augmenting the conventional approach with artificial intelligence (AI) opens the door to personalized pharmacotherapy in epilepsy. However, more work is needed before these models are ready for primetime clinical practice.

Electro-responsive micelle-based universal drug delivery system for on-demand therapy in epilepsy

A universal drug delivery system (DDS) with brain-targeted ability is demanded to enhance antiepileptic therapeutic efficacy and reduce side effects in multiple types of epileptic seizures. In this study, we reported a micelle-based DDS possessing the brain-targeted ability and electro-responsive feature for universal delivery of antiepileptic drugs (AEDs). The system is fabricated by ferrocene (Fc)-conjugated D-a-tocopherol polyethylene glycol succinate and amphiphilic block copolymer, which improve the drug encapsulation of different AEDs. Interestingly, the intrinsic nature of TPGS-Fc including transferrin receptor-mediated transcytosis and efflux pump inhibition endows the system with high permeability across the blood-brain barrier. Based on the hydrophobic-hydrophilic transition of Fc, the micelles can respond to epileptiform discharges and thus release the loaded AEDs. Improved antiepileptic efficacy of the micelles has been demonstrated in acute, continuous, and chronic epilepsy models. In summary, we have developed a universal micelle-based DDS for various AEDs delivery, which provides a promising approach to on-demand therapy of different epileptic seizures.

Sex differences in neuroimmunoendocrine communication. Involvement on longevity

Endocrine, nervous, and immune systems work coordinately to maintain the global homeostasis of the organism. They show sex differences in their functions that, in turn, contribute to sex differences beyond reproductive function. Females display a better control of the energetic metabolism and improved neuroprotection and have more antioxidant defenses and a better inflammatory status than males, which is associated with a more robust immune response than that of males. These differences are present from the early stages of life, being more relevant in adulthood and influencing the aging trajectory in each sex and may contribute to the different life lifespan between sexes.

Identification of hub genes significantly linked to subarachnoid hemorrhage and epilepsy via bioinformatics analysis

Background

Although epilepsy has been linked to subarachnoid hemorrhage (SAH), the underlying mechanism has not been fully elucidated. This study aimed to further explore the potential mechanisms in epilepsy and SAH through genes.

Methods

Gene expression profiles for subarachnoid hemorrhage (GSE36791) and epilepsy (GSE143272) were downloaded from the Gene Expression Omnibus (GEO) database. Differential expression analysis was performed to identify the common differentially expressed genes (DEGs) to epilepsy and SAH, which were further analyzed by functional enrichment analysis. Single-sample gene set enrichment analysis (ssGSEA) and weighted correlation network analysis (WGCNA) were used to identify common module genes related to the infiltration of immune cells in epilepsy and SAH. Hub module genes were identified using a protein-protein interaction (PPI) network. Finally, the most relevant genes were obtained by taking the intersection points between the DEGs and hub module genes. We performed validation by retrospectively analyzing the RT-PCR levels of the most relevant genes in patients with pure SAH and patients with SAH complicated with epilepsy. Our experiments verified that the SAH and SAH+epilepsy groups were significantly different from the normal control group. In addition, significant differences were observed between the SAH and SAH+epilepsy groups.

Results

In total, 159 common DEGs-85 downregulated genes and 74 upregulated genes-were identified. Functional analysis emphasized that the immune response was a common feature to epilepsy and SAH. The results of ssGSEA and WGCNA revealed changes in immunocyte recruitment and the related module genes. Finally, MMP9 and C3aR1 were identified as hub genes, and RT-PCR confirmed that the expression levels of the hub genes were higher in epilepsy and SAH samples than in normal samples.

Conclusions

Our study revealed the pathogenesis of SAH complicated with epilepsy and identified hub genes that might provide new ideas for further mechanistic studies.

A Comprehensive Review on Anti-Inflammatory Response of Flavonoids in Experimentally-Induced Epileptic Seizures

Flavonoids, a group of natural compounds with phenolic structure, are becoming popular as alternative medicines obtained from plants. These compounds are reported to have various pharmacological properties, including attenuation of inflammatory responses in multiple health issues. Epilepsy is a disorder of the central nervous system implicated with the activation of the inflammatory cascade in the brain. The aim of the present study was to summarize the role of various neuroinflammatory mediators in the onset and progression of epilepsy, and, thereafter, to discuss the flavonoids and their classes, including their biological properties. Further, we highlighted the modulation of anti-inflammatory responses achieved by these substances in different forms of epilepsy, as evident from preclinical studies executed on multiple epilepsy models. Overall, the review summarizes the available evidence of the anti-inflammatory potential of various flavonoids in epilepsy.

Epilepsy, Immunity and Neuropsychiatric Disorders

Several studies have focused on the emerging role of immunity and inflammation in a wide range of neurological disorders. Autoimmune diseases involving central nervous system share well defined clinical features including epileptic seizures and additional neuropsychiatric symptoms, like cognitive and psychiatric disturbances. The growing evidence about the role of immunity in the pathophysiologic mechanisms underlying these conditions lead to the concept of autoimmune epilepsy. This relatively-new term has been introduced to highlight the etiological and prognostic implications of immunity in epileptogenesis. In this review, we aim to discuss the role of autoimmunity in epileptogenesis and its clinical, neurophysiological, neuroimaging and therapeutic implications. Moreover, we wish to address the close relationship between immunity and additional symptoms, particularly cognitive and psychiatric features, which deeply impact clinical outcomes in these patients. To assess these aspects, we first analyzed Rasmussen's encephalitis. Subsequently, we have covered autoimmune encephalitis, particularly those associated with autoantibodies against surface neuronal antigens, as these autoantibodies express a direct immune-mediated mechanism, different from those against intracellular antigens. Then, we discussed the connection between systemic immune disorders and neurological manifestations. This review aims to highlight the need to expand knowledge about the role of inflammation and autoimmunity in the pathophysiology of neurological disorders and the importance to early recognize these clinical entities. Indeed, early identification may result in faster recovery and a better prognosis.

Childhood neurodevelopmental disorders and maternal diabetes: A population-based cohort study

AIM

To assess the risk of a wide spectrum of neurodevelopmental disorders (NDDs) in offspring of mothers with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and gestational diabetes mellitus (GDM).

METHOD

This retrospective cohort study included 877 233 singletons born between 2004 and 2008 in Taiwan. Children were followed up to 2015 for diagnoses of NDDs, including autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), developmental delay, intellectual disability, cerebral palsy, and epilepsy/infantile spasms using health insurance claims data. We performed Cox regression models to estimate the relative risks of NDDs associated with maternal diabetes. Covariates included parental age, year of birth, child sex, family income, urbanization level, hypertensive disorder, and preterm delivery status.

RESULTS

In utero there were 338 (0.04%) children exposed to T1DM, 8749 (1.00%) to T2DM, and 90 200 (10.28%) to GDM. The effect of T1DM on NDDs was the largest, followed by T2DM, then GDM. T1DM was associated with an increased risk of developmental delay, intellectual disability, and epilepsy/intellectual spasms in offspring. T2DM was associated with an increased risk of ASD, ADHD, developmental delay, intellectual disability, cerebral palsy, and epilepsy/intellectual spasms. GDM was associated with an increased risk of ASD, ADHD, and developmental delay.

INTERPRETATION

Maternal diabetes during pregnancy, including T1DM, T2DM, and GDM, is associated with an increased risk of some NDDs in offspring.

Sirtuins (SIRTs) As a Novel Target in Gastric Cancer

Gastric cancer is a major health burden worldwide. Among all neoplasms, gastric cancer is the fifth most common and the third most deadly type of cancer. It is known that sirtuins (SIRTs), are NAD⁺-dependent histone deacetylases regulating important metabolic pathways. High expression of SIRTs in the human body can regulate metabolic processes; they prevent inflammation but also resist cell death and aging processes. The seven members of this family enzymes can also play a fundamental role in process of carcinogenesis by influencing cell viability, apoptosis and metastasis. This review collects and discusses the role of all seven sirtuins (SIRT1-SIRT7) in the pathogenesis of gastric cancer (GC).

Inflammation-related genes and immune infiltration landscape identified in kainite-induced temporal lobe epilepsy based on integrated bioinformatics analysis

BACKGROUND

Temporal lobe epilepsy (TLE) is a common brain disease. However, the pathogenesis of TLE and its relationship with immune infiltration remains unclear. We attempted to identify inflammation-related genes (IRGs) and the immune cell infiltration pattern involved in the pathological process of TLE via bioinformatics analysis.

MATERIALS AND METHODS

The GSE88992 dataset was downloaded from the Gene Expression Omnibus (GEO) database to perform differentially expressed genes screening and weighted gene co-expression network analysis (WGCNA). Subsequently, the functional enrichment analysis was performed to explore the biological function of the differentially expressed IRGs (DEIRGs). The hub genes were further identified by the CytoHubba algorithm and validated by an external dataset (GSE60772). Furthermore, the CIBERSORT algorithm was applied to assess the differential immune cell infiltration between control and TLE groups. Finally, we used the DGIbd database to screen the candidate drugs for TLE.

RESULTS

34 DEIRGs (33 up-regulated and 1 down-regulated gene) were identified, and they were significantly enriched in inflammation- and immune-related pathways. Subsequently, 4 hub DEIRGs (Ptgs2, Jun, Icam1, Il6) were further identified. Immune cell infiltration analysis revealed that T cells CD4 memory resting, NK cells activated, Monocytes and Dendritic cells activated were involved in the TLE development. Besides, there was a significant correlation between hub DEIRGs and some of the specific immune cells.

CONCLUSION

4 hub DEIRGs (Ptgs2, Jun, Icam1, Il6) were associated with the pathogenesis of TLE via regulation of immune cell functions, which provided a novel perspective for the understanding of TLE.

Long non-coding RNA Tug1 regulates inflammation in microglia and in status epilepticus rats through the NF-κB signaling pathway

Background

Inflammation plays an important role in the pathogenesis of status epilepticus (SE). The long non-coding RNA (lncRNA) taurine up-regulated gene1 (Tug1) plays a well-defined role in inflammatory diseases. However, the molecular mechanism of Tug1 in SE progression remains unknown. In present study, we investigated whether Tug1 is involved in microglial inflammation in SE rats.

Methods

The SE rat model was established via intraperitoneal injection of lithium chloride-pilocarpine. RNA-binding protein immunoprecipitation (RIP) and RIP sequencing were carried out in rat microglia (RM). Tug1 cloned into the adenovirus was overexpressed in the microglia. Knockdown of Tug1 was performed via siRNA transfection. The level of Tug1 and inflammatory factors IL-1β and TNF-α was examined by real-time polymerase chain reaction (RT-PCR) and western blotting. Protein levels of p65, p-p65, p-ΙκΒα and ΙκΒα were assessed by western blotting.

Results

The RIP-seq result showed 14 lncRNAs that bound to the NF-κB p65 protein in RM. The lncRNA Tug1 directly interacted with p65. The level of declined Tug1 was decreased in the hippocampus of SE rats. Overexpression of Tug1 reduced the LPS-induced inflammation and M1/M2 polarization of microglia, while knockdown of Tug1 aggravated the inflammatory response in microglia. Accordingly, the protein levels of p-p65/p65 and p-ΙκΒα/ΙκΒα were reduced in the Tug1-overexpression microglia and elevated in the Tug1-knockdown microglia.

Conclusions

These findings indicate that Tug1 modulates the inflammation in microglia through the NF-κB signal pathway, and the Tug1/P65 axis are like to play a significant role in the inflammatory processes, providing a valid target for the therapy of SE.

Epilepsy-associated comorbidities among adults: A plausible therapeutic role of gut microbiota

Epilepsy is a debilitating disorder that affects about 70 million people in the world currently. Most patients with epilepsy (PWE) often reported at least one type of comorbid disorder. These may include neuropsychiatric disorders, cognitive deficits, migraine, cardiovascular dysfunction, systemic autoimmune disorders and others. Current treatment strategies against epilepsy-associated comorbidities have been based on targeting each disorder separately with either anti-seizure medications (ASMs), anti-inflammatories or anti-depressant drugs, which have often given inconsistent and ineffective results. Gut dysbiosis may be a common pathological pathway between epilepsy and its comorbid disorders, and thus may serve as a possible intervention target. Therefore, this narrative review aimed to elucidate the potential pathological and therapeutic role of the gut microbiota in adult epilepsy-associated comorbidities. This review noticed a scarcity in the current literature on studies investigating the direct role of the gut microbiota in relation to epilepsy-associated comorbidities. Nevertheless, gut dysbiosis have been implicated in both epilepsy and its associated comorbidities, with similarities seen in the imbalance of certain gut microbiota phyla (Firmicutes), but differences seen in the mechanism of action. Current gut-related interventions such as probiotics have been consistently reported across studies to provide beneficial effects in correcting gut dysbiosis and improving various disorders, independent of epilepsy. However, whether these beneficial effects may translate towards epilepsy-associated comorbidities have yet to be determined. Thus, future studies determining the therapeutic potential of gut microbiota interventions in PWE with epilepsy-associated comorbidities may effectively improve their quality of life.

Changes of Cytokines in Children With Tic Disorder

Tic disorder (TD) is a common childhood-onset disease associated with abnormal development of brain networks involved in the motor and sensory processing. The underlying pathophysiological mechanisms in TD are still unclear. An involvement of immune mechanisms in its pathophysiology has been proposed. This study investigates the association between the changes of cytokines and the etiology and development of TD. Different expressions of cytokines in a larger number of samples in our study may provide new insights to the field. The levels of cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ) were evaluated in 1,724 patients who were clinically diagnosed with TD from 1 to 17.5 years old and 550 were from 6 months to 14.5 years old in the control group. We assessed the levels of cytokines according to the patient's medication status and the severity of the disease. Of the cytokines we investigated, the serum IL-6 concentration of children with TD was significantly higher than that of the control group, while the levels of other cytokines were lower in TD patients. In the patient group whose YTGSS score ranged from 1 to 9, the IL-4, IL-10, and IFN-γ levels increased in medication group compared to unmedication group. Our data suggested that the cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ) may play an important role in the etiology and the severity in TD. Whether drug intervention in the early stage of tic disorder has a better effect on children needs further research.