Anti-brain antibodies in PANDAS versus uncomplicated streptococcal infection

The objective of this study was to assess brain involvement through the presence of antineuronal antibodies in Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS) and in uncomplicated active Group A streptococcal infection. We compared serum antibrain antibody to human basal ganglia sections assessed by indirect tissue immunofluorescence in two groups: a PANDAS group, comprised of 22 patients (mean age 10.1 years; 20 male, 2 female) who met strict National Institutes of Mental Health diagnostic criteria for PANDAS and had clinically active tics or obsessive-compulsive disorder, or both; and a GABHS control group consisting of 22 patients (mean age 9.1 years; 15 mol/L, 7 female) with clinical evidence of active Group A β-hemolytic streptococcal (GABHS) infection confirmed by throat culture and elevated antistreptolysin O titers but without history or clinical evidence of tics or obsessive-compulsive disorder. We observed positive anti-basal ganglia staining (defined as detectable staining at 1:10 serum dilution) in 14/22 patients in the PANDAS group (64%) but only 2/22 (9%) in the GABHS control group (P <0.001, Fisher's exact test). These results suggest that antibrain antibodies are present in children with PANDAS that cannot be explained merely by a history of GABHS infection.