Serum antibodies against human caudate, putamen, and globus pallidus were assayed by enzyme-linked immunosorbent assay (ELISA) and Western blot techniques in 41 children (mean age, 11 years) with Tourette syndrome (TS) and 39 controls, and results were correlated with clinical findings and markers of streptococcal infection (antistreptolysin O (ASO) and antideoxyribonuclease B (antiDNAse-B)), in a study at Johns Hopkins Hospital, Baltimore, MD. TS children had significant increases in mean and median ELISA optical density (OD) levels of serum antibodies against putamen, but not caudate or globus pallidus, and 61% of the TS group compared to 33% of controls had levels greater than the mean. TS patients with familial tics had higher ELISA antibody values. Specific antibodies to caudate/putamen measured by Western blot techniques occurred more frequently in TS subjects cf controls. Age of tic onset, tic severity, and associated ADHD or OCD showed no correlations with antibody levels. The risk ratio for abnormal streptococcal titers in TS subjects was similar to controls, and elevated putamen ELISA levels and ASO titers were not correlated. However, a subgroup analysis of subjects with elevated streptococcal titers showed a significantly larger number of TS children with elevated OD serum antibodies against putamen. 
COMMENT. Children with Tourette syndrome have significantly increased antineuronal serum antibody levels against putamen, suggesting an immune mechanism, but the relation of TS to ASO titers is equivocal and manifested only by subgroup analyses. Immune-based interventions, including penicillin therapy, for tics deserve further study. My own experience with limited open trials of penicillin treatment in ADHD patients with comorbid tics and elevated ASO titers is encouraging.
Dr Roger Kurlan, University of Rochester, NY, reviews research results of pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) and their limitations . Criteria for diagnosis of TS-PANDAS include childhood onset of tics, and sudden onset or exacerbations related to streptococcal infection.