title: Elevated levels of kynurenic acid in the cerebrospinal fluid of male patients with schizophrenia.
abstract: Previous studies have shown that endogenous brain levels of kynurenic acid (KYNA), a glutamate receptor antagonist, are elevated in patients with schizophrenia. Here we analyse KYNA in the cerebrospinal fluid (CSF) from a large cohort, including male healthy controls (n=49) and male patients with schizophrenia (n=90). We found that male patients with schizophrenia had significantly higher levels of CSF KYNA compared to healthy male controls (1.45 nM+/-0.10 vs. 1.06 nM+/-0.06 in the control group). Furthermore, when the patients with schizophrenia were divided into subgroups we found that CSF KYNA levels were significantly elevated in drug-naïve, first episode patients (1.53 nM+/-0.19, n=37) and in patients undergoing treatment with antipsychotic drugs (1.53 nM+/-0.17, n=34) compared to healthy male controls. No elevated CSF KYNA levels were detected in drug-free patients with schizophrenia, i.e. patients previously undergoing antipsychotic medications but drug-free at time of sampling (1.16 nM+/-0.10, n=19). Present results confirm that CSF KYNA concentration is elevated in patients with schizophrenia and are consistent with the hypothesis that KYNA contributes to the pathophysiology of the disease.
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institutet, SE-171 77 Stockholm, Sweden. Linda.Nilsson@fyfa.ki.se
authors.forename: L K
authors.initials: LK
authors.lastname: Nilsson
authors.forename: K R
authors.initials: KR
authors.lastname: Linderholm
authors.forename: G
authors.initials: G
authors.lastname: Engberg
authors.forename: L
authors.initials: L
authors.lastname: Paulson
authors.forename: K
authors.initials: K
authors.lastname: Blennow
authors.forename: L H
authors.initials: LH
authors.lastname: Lindström
authors.forename: C
authors.initials: C
authors.lastname: Nordin
authors.forename: A
authors.initials: A
authors.lastname: Karanti
authors.forename: P
authors.initials: P
authors.lastname: Persson
authors.forename: S
authors.initials: S
authors.lastname: Erhardt
mesh_terms: D000293:Adolescent; D000328:Adult; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007736:Kynurenic Acid / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000134:cerebrospinal fluid*; D012720:Severity of Illness Index
chemical_list: D007736:Kynurenic Acid