title: Amino acid cerebrospinal fluid/plasma ratios in children: influence of age, gender, and antiepileptic medication.
abstract: OBJECTIVE
  The purpose of this work was to investigate the influence of age, gender, and antiepileptic therapy on amino acid cerebrospinal fluid/plasma ratios in children.
  
  
  METHODS
  Concentrations of 17 amino acids measured by ion-exchange chromatography with ninhydrin detection in plasma and cerebrospinal fluid from 68 patients with neurologic diseases were used to calculate their cerebrospinal fluid/plasma ratios (70 measurements; 28 female patients [29 punctures] and 40 male patients [41 punctures]). Age dependence and the effects of gender and antiepileptic medication on amino acid cerebrospinal fluid/plasma ratios were investigated by linear multiple regression analysis, and nonstandardized predicted mean values for 2 age groups were calculated (cutoff: 3 years old).
  
  
  RESULTS
  The cerebrospinal fluid/plasma ratios ranged between 0.02 for glycine and 0.93 for glutamine. Age had a significant influence on cerebrospinal fluid/plasma ratios for valine, isoleucine, leucine, and tyrosine, with higher ratios in younger children. Gender had a significant influence only on the glutamine cerebrospinal fluid/plasma ratio (female patients had lower ratios). Cerebrospinal fluid/plasma ratios of glutamine and tyrosine were significantly elevated by valproate therapy and those of serine, asparagine, glutamine, valine, methionine, and phenylalanine by phenobarbital therapy. No significant influence of age, gender, and antiepileptic drugs was detectable on cerebrospinal fluid/plasma ratios of threonine, proline, glycine, alanine, histidine, ornithine, lysine, and arginine.
  
  
  CONCLUSIONS
  Cerebrospinal fluid/plasma ratios, especially for essential neutral amino acids and for serine, asparagine, and glutamine were influenced to different degrees by age, gender, and antiepileptic therapy.
authors.affiliation: Division of Neonatology, Neuropediatrics, and Inborn Errors of Metabolism, Innsbruck Medical University, Innsbruck, Austria. sabine.scholl-buergi@uki.at
authors.forename: Sabine
authors.initials: S
authors.lastname: Scholl-Bürgi
authors.forename: Edda
authors.initials: E
authors.lastname: Haberlandt
authors.forename: Peter
authors.initials: P
authors.lastname: Heinz-Erian
authors.forename: Florian
authors.initials: F
authors.lastname: Deisenhammer
authors.forename: Ursula
authors.initials: U
authors.lastname: Albrecht
authors.forename: Sara Baumgartner
authors.initials: SB
authors.lastname: Sigl
authors.forename: Markus
authors.initials: M
authors.lastname: Rauchenzauner
authors.forename: Hanno
authors.initials: H
authors.lastname: Ulmer
authors.forename: Daniela
authors.initials: D
authors.lastname: Karall
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000596:Amino Acids / Q000097:blood* / Q000134:cerebrospinal fluid*; D000927:Anticonvulsants / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015415:Biomarkers / Q000032:analysis; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004827:Epilepsy / Q000175:diagnosis* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000175:diagnosis / Q000188:drug therapy; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012640:Seizures / Q000175:diagnosis / Q000188:drug therapy; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D000596:Amino Acids; D000927:Anticonvulsants; D015415:Biomarkers