Elevated Plasma S100B, Psychotic Symptoms, and Cognition in Schizophrenia

Abstract

S100B is a calcium binding protein mainly produced by glial cells. Previous studies have shown elevated levels of S100B in patients with schizophrenia. We measured S100B levels in fasting plasma of 39 patients with schizophrenia and 19 adult healthy controls. We used linear regression to compare S100B between patients and controls. In patients only, we also investigated the relationship between S100B levels and psychotic symptoms (assessed by the Positive and Negative Syndrome Scale), and cognitive function (assessed by the NIH Toolbox Cognition Battery), respectively by calculating Pearson's correlation coefficients. Mean plasma S100B was significantly higher in the patient group than in the control group. There were no significant correlations between plasma S100B and psychotic symptoms or cognition.

Different serum protein factor levels in first‐episode drug‐naive patients with schizophrenia characterized by positive and negative symptoms

“…Serum levels of S100β have reportedly been correlated with deficit symptoms in schizophrenia patients at a mean age of 63 years, 64 whereas these levels have been reported as not associated with psychotic symptoms in a young sample with schizophrenia (a mean age of 33 years). 32 Our study used unmedicated and young schizophrenia patients (mean age of 23-24 years), which may have contributed to the non-association of serum levels of S100β with psychotic or negative symptoms in the present study.…”

“…This finding is consistent with previous findings of increased serum levels of S100β in schizophrenia patients compared with healthy controls. 32,59,60 S100β belongs to the S100-calmodulin-troponin superfamily and is mainly produced by astrocytes. 61 It has been postulated that S100β could exert either a neuroprotective effect (at nanomolecular concentrations) or an apoptosis-inducing effect (at micromolecular concentrations) depending on its concentration.…”

“…This finding is inconsistent with some previous findings, 34,64 but is supported by others. 32,65 The relation between serum levels of S100β and psychotic symptoms, especially negative symptoms, remains inconsistent so far. The relation may be influenced by several factors.…”

“…S100β can regulate the proliferation and differentiation of neurons and glia. 31 Studies have demonstrated that serum levels of S100β seem to be significantly higher in schizophrenia patients, 18,32 and increased serum levels of S100β are positively correlated with the negative symptoms of schizophrenia. [33][34][35] To date, accumulating studies have indicated that multiple dysfunctions in dopaminergic, glutamatergic, serotonergic, and gammaaminobutyric acid (GABA)-ergic signaling might be involved in the pathophysiology of schizophrenia.…”

Oxidative-Antioxidant Imbalance and Impaired Glucose Metabolism in Schizophrenia

“…Claudin-5 proteins are absent along the blood vessels of the brain of schizophrenic patients, which may be associated with the penetration of low-molecular blood elements, e.g., S100β, resulting in impaired brain homeostasis [253]. The calcium-binding S100β protein is mainly produced by astrocytes [253,256,257]. An increase in plasma S100β levels shows a positive correlation with the occurrence of negative symptoms of schizophrenia and cognitive disorders [254].…”