Search

Brain-derived neurotrophic factor (BDNF) and the immune-inflammatory response system (IRS) have been implicated in the pathophysiology of schizophrenia. However, no research examined the associations between BDNF and immune activation both before and after treatment in antipsychotic-naïve first episode psychosis (AN-FEP). This study aims to examine serum BDNF levels and their association with IRS and the compensatory immune-regulatory reflex system (CIRS) in AN-FEP before and after risperidone treatment. We included 31 AN-FEP and 22 healthy controls. AN-FEP showed reduced levels of BDNF as compared to controls, and BDNF levels normalized after treatment with risperidone. BDNF levels were inversely correlated with a greater IRS response. Higher levels of IRS/CIRS biomarkers were associated with lower levels of BDNF including M1 macrophage, T-helper (Th)-1, Th-2, and Th-17, and T-regulatory (Treg) cell responses. Our findings indicate that AN-FEP is characterized by decreased levels of BDNF, which are normalized after treatment with risperidone. BDNF levels were inversely associated with activated immune-inflammatory pathways. The findings support the hypothesis that, increased IRS is linked to neurotoxicity, and that a decrease in BDNF may be part of the IRS/CIRS responses in FEP and, thus, be involved in the development of psychosis., (Copyright © 2021. Published by Elsevier Ltd.)

Recent research has demonstrated that telomere maintenance might be a key integrating point for the cumulative effect of genetic and environmental factors in patients with first-episode psychosis (FEP) and schizophrenia (SCZ). Eighty-one participants with antipsychotic-naïve FEP, 173 with SCZ and 438 HC were enrolled in this study. Psychiatric diagnosis was assessed using the Semi-Structured Clinical Interview for DSM-IV Axis-I (SCID-I). The Positive and Negative Syndrome Scale (PANSS), Young Mania Rating Scale (YMRS) and Calgary Depression Scale for Schizophrenia (CDSS) were used to measure symptoms severity. Telomere length (TL) was determined using a multiplex qPCR assay. After adjustment for age, years of education, and smoking status, we found that patients with SCZ had longer TL (relative ratio (RR) = 1.08) than the HC group (RR = 1.00, Wald χ 2  = 12.48, p = 0.002). Further, non-remitted SCZ patients presented longer TL (RR = 1.00) compared to remitted SCZ (RR = 0.88, Wald χ 2  = 7.20, p = 0.007). TL in patients also correlated to psychopathology assessment in terms of total (p = 0.003) and positive PANSS scores (p = 0.001). No correlation with negative PANSS, YMRS, and CDSS or effects of medication was found on TL. Although the exact pathways underlying longer TL in SCZ patients remain unclear, these findings raise more questions than answers and suggest that TL may be of immense value on SCZ progression. Further studies are required to investigate the association of TL in FEP and SCZ., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Schizophrenia is a neurodevelopmental disorder that produces abnormalities across different brain regions. Measuring structural covariance with MRI is a well-established approach to investigate common changes in distinct systems. We investigated structural covariance in schizophrenia in a large Brazilian sample of individuals with chronic schizophrenia (n = 143), First Episode Psychosis (n = 32), and matched healthy controls (n = 82) using a combination of graph analysis and computational neuroanatomy. Firstly, we proposed the connectivity-closeness and integrity-closeness centrality measures and them compared healthy controls with chronic schizophrenia regarding these metrics. We then conducted a second analysis on the mapped regions comparing the pairwise difference between the three groups. Our results show that compared with controls, both patient groups (in pairwise comparisons) had a reduced integrity-closeness in pars orbitalis and insula, suggesting that the relationship between these areas and other brain regions is increased in schizophrenia. No differences were found between the First Episode Psychosis and Schizophrenia groups. Since in schizophrenia the brain is affected as a whole, this may mirror that these regions may be related to the generalized structural alteration seen in schizophrenia., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Schizophrenia is accompanied by increased lipid peroxidation and nitric oxide (NO) levels and by lowered antioxidant levels. However, the effect of antipsychotic agents on these processes remains unclear. The objective of this study is to determine the oxidative stress (OS) status in drug naïve first-episode psychotic patients (FEP) compared to healthy controls and to delineate the effects of risperidone on these biomarkers., Methods: 51 drug naive FEP patients and 61 healthy controls were enrolled; FEP patients were reassessed 11 weeks after risperidone treatment. Three OS biomarkers, i.e. lipid hydroperoxides - LOOH, NO metabolites - NOx, and advanced oxidation protein products - AOPP, and two antioxidant biomarkers, i.e. total radical-trapping antioxidant parameter - TRAP, and paraoxonase 1 - PON1, were measured. The Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS) were used to measure symptoms severity., Results: Significantly lower PON1 activity and increased TRAP values were found in FEP patients. There were no significant associations between any of the OS/antioxidant biomarkers and clinical data. Risperidone treatment significantly increased PON1 activity and decreased LOOH levels. These effects of risperidone were not significantly associated with the clinical response and risperidone dosage., Discussion: Changes in antioxidant profile, but not in lipid or protein oxidation or increased NO production, were found in drug-naive FEP. Risperidone may have antioxidant effects by lowering lipid peroxidation and increasing the antioxidant defenses against lipid peroxidation related to PON1. None of the biomarkers predicted treatment outcome., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A study of the gene expression levels in the blood of individuals with schizophrenia in the beginning of the disease, such as first-episode psychosis (FEP), is useful to detect gene expression changes in this disorder in response to treatment. Although a large number of genetic studies on schizophrenia have been conducted, little is known about the effects of antipsychotic treatment on gene expression. The aim of the present study was to examine differences in the gene expression in the blood of antipsychotic-naïve FEP patients before and after risperidone treatment (N = 44) and also to verify the correlation with treatment response. In addition, we determined the correlations between differentially expressed genes and clinical variables. The expression of 40 neurotransmitter and neurodevelopment-associated genes was assessed using the RT2 Profiler PCR Array. The results indicated that the GABRR2 gene was downregulated after risperidone treatment, but no genes were associated with response to treatment and clinical variables after Bonferroni correction. GABRR2 downregulation after treatment can both suggest an effect of risperidone treatment or processes related to disease progression, either not necessarily associated with the improvement of symptoms. Despite this change was observed in blood, this decrease in GABRR2 mRNA levels might be an effect of changes in GABA concentrations or other systems interplay consequently to D2 blockage induced by risperidone, for example. Thus, it is important to consider that antipsychotics or the progression of psychotic disorders might interfere with gene expression., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objective: To investigate possible differences in peripheral levels of chemokines, BDNF and oxidative markers between patients with Schizophrenia (SZ) and matched healthy controls, and investigate the correlation of these biomarkers with cognitive performance., Methods: Thirty individuals with SZ and 27 healthy controls were included and the following plasmatic biomarkers' levels were determined according to manufacturers' instructions: BDNF, TBARS, protein carbonyl content (PCC) and the chemokines CXCL-10/IP-10, CXCL-8/IL-8, CCL-11, CCL-24/Eotaxin-2, CCL-2/MCP-1, CCL-3/MIP-1. Selected neuropsychological tasks were administered to assess verbal learning (Hopkins Verbal Learning Test), verbal fluency (FAS test), working memory (Visual Working Memory Task, Keep Track Task, Letter Memory Task), set shifting (Plus-minus task, Number-letter task), inhibition (Computerized Stroop Task, Semantic Generation Task) and complex executive function tasks (Tower of London and the shortened version of the WCST-64)., Results: Compared with the healthy control group, individuals with SZ presented significantly higher levels of BDNF and the chemokine CCL-11, and lower levels of TBARS and the chemokine CXCL-10/IP-10. When we examined only the SZ group, BDNF levels were positively correlated with semantic generation tasks. Working memory ability was negatively correlated with PCC. Regarding chemokines, CCL-11 was negatively correlated to performance in working memory test, and positively correlated with cognitive flexibility task. CXCL-8/IL-8 was positively correlated with verbal fluency. CCL-24/Eotaxin-2 was positively correlated with semantic generation ability and letter memory task., Conclusions: Our results indicate that cognitive performance in SZ is associated with mediators of neuroplasticity that can be measured peripherally., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Schizophrenia (SZ) has been associated with an imbalance in the inflammatory cytokine TNF-α. The objectives of this study were to compare TNF-α and its soluble receptors' serum levels in individuals with SZ with the levels found in a group of healthy volunteers and to investigate the possible association between these biomarkers and the dimensions and severity of symptoms, clinical outcomes and response to treatment in patients with SZ., Methods: Fifty-four chronically medicated SZ outpatients and 118 healthy controls were included in the study. TNF-α levels were measured by Cytometric Bead Assay (CBA), and serum levels of soluble tumor necrosis factor receptor 1 (sTNFR1) and soluble tumor necrosis factor receptor 2 (sTNFR2) were measured by ELISA., Results: sTNFR1 and sTNFR2 were significantly elevated in patients with SZ as compared to the healthy control group. In the group of individuals with SZ, the levels of both types of soluble TNF receptors showed a negative correlation with global functioning. sTNFR1 levels were higher in the treatment-resistant patients as compared to the non-treatment-resistant patients and the controls. sTNFR1 levels were also heightened in patients with SZ and concomitant depression., Conclusion: Our findings reinforce that SZ is associated with an inflammatory profile and suggest that sTNFR1 is a marker of a treatment-resistance and severe clinical course in SZ., (Copyright © 2013 Elsevier Ltd. All rights reserved.)