title: Systematic review and meta-analysis of circulating S100B blood levels in schizophrenia.
abstract: S100B is a calcium-binding protein secreted in central nervous system from astrocytes and other glia cells. High blood S100B levels have been linked to brain damage and psychiatric disorders. S100B levels have been reported to be higher in schizophrenics than healthy controls. To quantify the relationship between S100B blood levels and schizophrenia a systematic literature review of case-control studies published on this topic within July 3rd 2014 was carried out using three bibliographic databases: Medline, Scopus and Web of Science. Studies reporting mean and standard deviation of S100B blood levels both in cases and controls were included in the meta-analysis. The meta-Mean Ratio (mMR) of S100B blood levels in cases compared to controls was used as a measure of effect along with its 95% Confidence Intervals (CI). 20 studies were included totaling for 994 cases and 785 controls. Schizophrenia patients showed 76% higher S100B blood levels than controls with mMR = 1.76 95% CI: 1.44-2.15. No difference could be found between drug-free patients with mMR = 1.84 95%CI: 1.24-2.74 and patients on antipsychotic medication with mMR = 1.75 95% CI: 1.41-2.16). Similarly, ethnicity and stage of disease didn't affect results. Although S100B could be regarded as a possible biomarker of schizophrenia, limitations should be accounted when interpreting results, especially because of the high heterogeneity that remained >70%, even after carrying out subgroups analyses. These results point out that approaches based on traditional categorical diagnoses may be too restrictive and new approaches based on the characterization of new complex phenotypes should be considered.
authors.affiliation: Institute of Public Health, Section of Hygiene, Department of Public Health, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Katina
authors.initials: K
authors.lastname: Aleksovska
authors.affiliation: Institute of Public Health, Section of Hygiene, Department of Public Health, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Leoncini
authors.affiliation: Area of Systems Approaches and Non Communicable Diseases, Unit of Clinical and Molecular Epidemiology, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bonassi
authors.affiliation: Deputy Scientific Director and Systems Medicine Coordinator, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Cesario
authors.affiliation: Institute of Public Health, Section of Hygiene, Department of Public Health, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Boccia
authors.affiliation: Area of Systems Approaches and Non Communicable Diseases, Unit of Clinical and Molecular Epidemiology, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Frustaci
mesh_terms: D006801:Humans; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*; D012559:Schizophrenia / Q000097:blood*
chemical_list: D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human