title: Diagnostic Accuracy of Brain-derived Neurotrophic Factor and Nitric Oxide in Patients with Schizophrenia: A pilot study.
abstract: BACKGROUND
  Brain-derived neurotrophic factor (BDNF) and nitric oxide (NO) play multiple roles in the developing and adult CNS. Since BDNF and NO metabolisms are dysregulated in schizophrenia, we measured these markers simultaneously in the blood of schizophrenics and assessed their diagnostic accuracy.
  
  
  METHODS
  Thirty-eight patients with schizophrenia classified according to demographic characteristics, symptomatologyand therapy and 39 age- and gender-matched healthy controls were enrolled. BDNF was determined by the ELISA technique while the concentration of nitrite/nitrate ([Formula: see text]) was measured by the colorimetric method.
  
  
  RESULTS
  Serum BDNF levels were significantly lower (20.38±3.73 ng/mL, P = 1.339E-05), whilst plasma [Formula: see text] concentrations were significantly higher (84.3 (72-121) μmol/L, P=4.357E-08) in patients with schizophrenia than in healthy controls (25.65±4.32 ng/mL; 60.9 (50-76) μmol/L, respectively). The lowest value of BDNF (18.14±3.26 ng/mL) and the highest [Formula: see text] concentration (115.3 (80-138) μmol/L) were found in patients treated with second-generation antipsychotics (SGA). The patients diseased before the age of 24 and the patients suffering for up to one year had significantly lower serum BDNF levels than those diseased after the age of 24 and the patients who were ill longer than one year. Both BDNF and [Formula: see text] showed good diagnostic accuracy, but BDNF had better ROC curve characteristics, especially in patients with negative symptomatology.
  
  
  CONCLUSIONS
  BDNF and nitrite/nitrate showed inverse changes in schizophrenic patients. The most pronounced changes were found in patients treated with second-generation antipsychotics. Although BDNF is not specific of schizophrenia, it may be a clinically useful biomarker for the diagnosis of patients expressing predominantly negative symptoms.
authors.affiliation: Clinic for Mental Health Protection, Clinical Centre Niš, Serbia.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Djordjević
authors.affiliation: Clinic for Psychiatry, Clinical Centre Niš, Serbia.
authors.forename: Dušan
authors.initials: D
authors.lastname: Lazarević
authors.affiliation: Centre for Medical Biochemistry, Clinical Centre Niš, Serbia.
authors.forename: Vladan
authors.initials: V
authors.lastname: Ćosić
authors.affiliation: Department of Neuroscience, University of Kragujevac, Serbia.
authors.forename: Marinela Z
authors.initials: MZ
authors.lastname: Knežević
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Niš, Serbia.
authors.forename: Vidosava B
authors.initials: VB
authors.lastname: Djordjević
authors.affiliation: Institute of Biochemistry, Faculty of Medicine, Niš, Serbia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Stojanović
keywords: ROC curve; brain-derived neurotrophic factor; nitric oxide; schizophrenia