Identification of anti-neuronal antibodies in the serum of patients with Tourette's syndrome

Tourette syndrome (TS) is a chronic multiple-tic disorder affecting 0.8 to 1% of the pediatric population. Consistent data support the presence of abnormalities of immune regulation in children with TS. Environmental factors acting on the immune system, such as group A Streptococcus (GAS) infection, could modify the course of the severity of tics and symptoms in TS. Structural similarity between streptococcal and cerebral antigens might elicit a pathogenic cross-reactivity of antibodies originally targeting GAS antigens to host antigens. Molecular mimicry models has been proposed involving cross-reactivity between streptococcal and neuronal proteins. Given the role of dopamine and dopamine receptors in the control of movement and behavior, we hypothesized that patients with TS harbored serum autoantibodies against dopamine receptors. In our work, we screen and measure the anti-neuronal antibodies in TS patient’s sera. Specifically, we use flow cytometry cell-based assay to test sera for the presence of autoantibodies binding to dopamine D2 (DRD2) and D1 receptors (DRD1) on surface of transfected HEK293 cells. Within the European Multicentre Tics in Children Studies project, financed under the 7th Framework Programme of the European Union, we measure IgG reactivity to DRD2, DRD1, of a thousand of Tourette’s sera from all Europe. The data thus obtained will present high statistical power and will represent the starting point for the diagnostic methodology of TS.