• DOI:10.1007/s00787-007-1009-1
• Corpus ID: 39150343

Plasma kynurenine and related measures in tic disorder patients

@article{Hoekstra2007PlasmaKA,
  title={Plasma kynurenine and related measures in tic disorder patients},
  author={Pieter J. Hoekstra and George M Anderson and Pieter W. Troost and Cees G. M. Kallenberg and Ruud B. Minderaa},
  journal={European Child \& Adolescent Psychiatry},
  year={2007},
  volume={16},
  pages={71-77}
}

• P. Hoekstra, G. Anderson, +2 authors R. Minderaa
• Published 15 May 2007
• Medicine, Biology, Psychology
• European Child & Adolescent Psychiatry

ObjectiveIncreased plasma kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of kynurenine and related molecules in a group of tic disorder patients.MethodsPlasma concentrations of tryptophan, kynurenine, cortisol, and neopterin were determined in Dutch tic disorder patients (N = 59), and healthy volunteers (N = 32). Group means were compared and age-controlled intra-individual correlations between tic severity and plasma levels of these molecules were examined.ResultsNo significant differences were found between patient and control groups in plasma levels of tryptophan, kynurenine, and cortisol concentrations, nor in the kynurenine/tryptophan ratio. However, neopterin was significantly (p = 0.035) higher in patients (mean = 5.13 nmol/l) than in controls (mean = 3.30 nmol/l). Plasma levels of these molecules did not correlate with tic severity, with the exception of tryptophan (r = −0.289, p = 0.049). In patients, plasma neopterin correlated with kynurenine (r = 0.438, p = 0.002); in healthy subjects, tryptophan correlated with kynurenine (r = 0.670, p < 0.001).ConclusionWhile the observed elevation in plasma neopterin is consistent with immune activation in a subset of tic disorder patients, metabolism of tryptophan through the kynurenine pathway appears to be unaltered in tic disorder patients.