A cytokine study in children and adolescents with Tourette's disorder.
BACKGROUND
While immune system dysregulation has been postulated to play a role in Tourette's disorder (TD), most research has focused on the hypothesis of an autoimmune process similar to rheumatic fever. This study examined the potential role of cytokines, modulators of the immune system. We hypothesized that children with TD would have increased levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-12, IL-1 beta and IL-6, and decreased IL-2. We also explored whether comorbid obsessive compulsive disorder (OCD) had an effect on the cytokine profile of TD patients.


METHODS
Thirty-two children and adolescents with TD (27 males, ages 7-18 years), 17 with comorbid OCD (14 males), and 16 healthy comparison subjects (7 males, ages 9-19), were enrolled. Plasma cytokines were examined using an enzyme-linked immunosorbent assay. The Mann-Whitney and binary logistic regression tests were used to compare the groups.


RESULTS
Only patients with comorbid OCD (TD+OCD; n=17) had significantly elevated IL-12 plasma levels compared to controls (2.73+/-5.12 pg/ml vs. 0.55+/-0.88 pg/ml, rank statistic=222.5; p<0.04). IL-2 was significantly higher in the TD+OCD subgroup compared to the non-OCD TD subgroup (0.74+/-0.29 pg/ml vs. 0.49+/-0.24 pg/ml, rank statistics=108.5; p<0.03). There were no other significant cytokine differences between groups.


CONCLUSIONS
Findings suggest a role for IL-12 and IL-2 in TD, and that the TD+OCD subgroup may involve different neuroimmunological functions than the TD-OCD subgroup. Larger studies with medication-free patients should follow.
Gabbay
Vilma
V
NYU Child Study Center, Child and Adolescent Psychiatry, New York University School of Medicine, 577 First Avenue, New York, NY 10016, USA. vilma.gabbay@nyumc.org
Coffey
Barbara J
BJ
Guttman
Leah E
LE
Gottlieb
Lev
L
Katz
Yisrael
Y
Babb
James S
JS
Hamamoto
Mia M
MM
Gonzalez
Charles J
CJ
D000293:Adolescent; D000367:Age Factors; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D018664:Interleukin-12 / Q000097:blood* / Q000502:physiology; D007376:Interleukin-2 / Q000097:blood* / Q000502:physiology; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000097:blood / Q000453:epidemiology / Q000523:psychology; D005879:Tourette Syndrome / Q000097:blood* / Q000453:epidemiology / Q000523:psychology; D055815:Young Adult
D007376:Interleukin-2; D018664:Interleukin-12