Association Between Anti-Basal Ganglia Antibodies And Streptococcal Infection In Children With Tourette's Syndrome

Background: The classical neurological disorder after group A beta hemolytic streptococcal infection is Sydenham's chorea. Recently a tic disorder occurring after group A streptococcal infection has been described and termed PANDAS (paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection). It is proposed that antibodies induced after group A streptococcal infection react with basal ganglia neurones in Sydenham's chorea and PANDAS, in a process involving molecular mimicry. Similar to the model for Sydenham's chorea and PANDAS, anti-basal ganglia antibodies (ABGA), which develop in response to a preceding group A beta hemolytic streptococcal infection, have been speculated to have a role in the development of Tourette's syndrome .Objective: To test the hypothesis that Tourette's syndrome may be associated with group A streptococcal infection and ABGA. Methods: 80 children with Tourette's syndrome (DSM-1V, mean age 9.8 years, range: 5 to 1 6 years, 65 boys and 15 girls), were enrolled in the study. 80 age-matched healthy children were studied as controls.Antistreptolysin O titers (ASOT) and antideoxyribonuclease B (antiDNase-B) titers were used to define recent group A streptococcal infection and determined on the Beckman Coulter IMMAGE System. Positive ASOT and antiDNase-B titers were determined by cutoffs of 120IU/ml and 200U/ml respectively. And it was considered to be positive antistreptococcal antibodies titers if one of ASOT and antiDNase-B titers was positive at least. Serum ABGA was detected using indirect immunofluorescence on unfixed frozen sections (8μm) from rat brain striatum. Results: The rate of positive ASOT was significant increase in Tourette's syndrome group (25%. 20/80). compared with that in control group (8.8%, 7/80) (p<0.01). AntiDNase-B titers was also raised in 27.5% (22/80) of the children with Tourette's syndrome and in 11.3% (9/80) of controls (p<0.01). Significant differences were found in the frequency of positive antistreptococcal antibodies titers between children with Tourette's syndrome (32.5% 26/80) and controls (12.5% 10/80) (p<0.01). A statistically significant increase in the prevalence of ABGA was found in children with Tourette's syndrome (43.8% 35/80). compared with the prevalence in controls (22.5% 18/80) (p<0.01). 48.6% of Tourette's syndrome children with positive ABGA indirect immunofluorescence had a positive antistreptococcal antibodies titers (17/35), compared with 20% of Tourette's syndrome children with negative ABGA indirect immunofluorescence (9/45) (p<0.01). There is a correlation between ABGA determinations and positive antistreptococcal antibodies titers. Conclusions: The results have shown that children with Tourette's syndrome have evidence of increase antistreptococcal antibodies titers and ABGA. These results support that a post-streptococcal autoimmunemay involve in the process of Tourette's syndrome.