title: Diagnostic performance of increased prolidase activity in schizophrenia.
abstract: We investigated whether prolidase activity has a diagnostic test value in schizophrenia and assessed the relation between prolidase activity and sociodemographic-clinical characteristics of patients with schizophrenia. Fifty patients with schizophrenia (diagnosed as schizophrenia according to DSM-V criteria) and 50 healthy volunteers were included in this study. Case and control groups had a similar distribution in age, sex, body mass index (BMI), and smoking status. Serum prolidase activity was measured in both groups and was determined to be significantly higher in the patient group (509.706±41.918) compared to the control group (335.4±13.6; t=6.231; p=0.0001). A cut-off point of 392.65U/L prolidase was determined for diagnostic measures from the plotted ROC curve. The area under the ROC curve was 1.000, which was significant (p<0.0001). Higher values were assigned as the disease state. Both positive predictive value (PPV) and negative predictive value (NPV) were 100% at the cut-off point of 392.650U/L. The prolidase levels of the control group were all below the cut-off point. There were no statistically significant differences between the two groups with regard to age, gender, or BMI (p>0.05), and no correlation was found between mean prolidase activity and age of onset of the disease, family history, disease duration, number of hospitalizations, subtypes of schizophrenia, PANSS scores or sub-scores, CGI-S scores, S-A scale scores, and the antipsychotic treatment (p>0.05). The results of this study indicate that serum prolidase activity may be a useful diagnostic test for schizophrenia; however, further studies are needed to verify this.
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: m63gunes@gmail.com.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Güneş
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: drmahmutbulut@yahoo.com.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Bulut
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: drsuleymandemir@gmail.com.
authors.forename: Süleyman
authors.initials: S
authors.lastname: Demir
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: aslihanokan@gmail.com.
authors.forename: Aslıhan Okan
authors.initials: AO
authors.lastname: İbiloğlu
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: mcemalkaya@yahoo.com.
authors.forename: Mehmet Cemal
authors.initials: MC
authors.lastname: Kaya
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: abdullahatli@yandex.com.
authors.forename: Abdullah
authors.initials: A
authors.lastname: Atlı
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: dribrahimkaplan@hotmail.com.
authors.forename: İbrahim
authors.initials: İ
authors.lastname: Kaplan
authors.affiliation: Department of Psychiatry, State Hospital of Afsin, Kahramanmaras, Turkey. Electronic address: dr.akif@gmail.com.
authors.forename: Mehmet Akif
authors.initials: MA
authors.lastname: Camkurt
authors.affiliation: Department of Psychiatry, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Electronic address: aytekinsir2010@gmail.com.
authors.forename: Aytekin
authors.initials: A
authors.lastname: Sir
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004150:Dipeptidases / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D012559:Schizophrenia / Q000175:diagnosis* / Q000201:enzymology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004150:Dipeptidases; C022449:proline dipeptidase
keywords: Biochemical marker; Diagnostic performance; Prolidase activity; Schizophrenia