Cytokine Levels Reflect Tic Symptoms more Prominently During Mild Phases

Various cytokines are involved in the neuroinflammatory circuitry of tic disorders. We aimed to identify the cytokines involved in the pathogenesis of tic disorders. We enrolled 44 patients with tic disorder and 38 healthy controls. Blood samples were analyzed using a Luminex® human cytokine multiplex assay kit. Patients were divided into groups with “mild tics” and “above moderate tics” based on Yale Global Tic Severity Scale (YGTSS) scores. In the mild tic group, interleukin (IL)-12 p70 negatively correlated with motor tic scores. Granulocyte-macrophage colony-stimulating factor, IL-4, IL-8, and tumor necrosis factor (TNF)-α were positively correlated to phonic tic scores. IL-12 p40 and TNF-α were positively correlated to total tic scores. IL-12 p70 and IL-17a negatively correlated to impairment scores and total YGTSS scores. Only patients with mild symptoms exhibit significant correlations, suggesting that correlations between cytokines and tic symptoms are more relevant during the mild or remission phases.