Increased anti-streptococcal antibodies in patients with Tourette's syndrome

Infection or postinfectious phenomena have been postulated to play a role i n the pathogenesis of children afflicted with the typical symptoms of Toure tte's syndrome (TS). We investigated whether an increase of titers of antis treptococcal antibodies can be reproduced in our children with TS, and whet her this increase is restricted to children. We examined the titers of two different antistreptococcal antibodies, antistreptolysin (ASL) and antiDNas e B, both in children and adults. Titers of ASO and antiDNase B were measur ed (1) in 13 children/adolescents suffering from TS and in an age-matched c omparison group; (2) in 23 adult patients, a comparison group of 23 age-mat ched controls, and in another group of 17 age-matched, non-medicated acute schizophrenics. ASO and antiDNase B titers were determined by laser nephelo metry using a commercially available kit. Two antistreptococcal cut-off lev els were compared(> 250 U/ml and > 400 U/ml). As expected, increased ASO ti ters (> 400 IU/ml) were found in a higher proportion of children/adolescent s with TS compared to healthy controls. In parallel, high antiDNase titers (> 250 U/ml or > 400 U/ml) were also observed in significantly more childre n/adolescents with TS compared to controls. Regarding adults, titers > 250 U/ml for both antistreptococcal antigens were found in significantly more T S patients than in schizophrenic patients or healthy control subjects. The mean values of ASO and antiDNase titers were significantly higher in both g roups of TS patients compared to control children/adolescents, to the compa rison groups of healthy adults and to schizophrenics. No difference in anti streptococcal titers was found between schizophrenics and the group of heal thy adults. TS patients exhibited higher antistreptococcal titers than age- matched comparison groups of both children/adolescents and adults using dif ferent types of calculation. Our findings support the theory that a postinf ectious immune mechanism may play a role in the pathogenesis of TS. The mec hanism still needs to be elucidated. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.