Nico van Beveren

Validation of a Blood-Based Laboratory Test to Aid in the Confirmation of a Diagnosis of Schizophrenia

We describe the validation of a serum-based test developed by Rules-Based Medicine which can be used to help confirm the diagnosis of schizophrenia. In preliminary studies using multiplex immunoassay profiling technology, we identified a disease signature comprised of 51 analytes which could distinguish schizophrenia (n = 250) from control (n = 230) subjects. In the next stage, these analytes were developed as a refined 51-plex immunoassay panel for validation using a large independent cohort of schizophrenia (n = 577) and control (n = 229) subjects. The resulting test yielded an overall sensitivity of 83% and specificity of 83% with a receiver operating characteristic area under the curve (ROC-AUC) of 89%. These 51 immunoassays and the associated decision rule delivered a sensitive and specific prediction for the presence of schizophrenia in patients compared to matched healthy controls.

An activated set point of T-cell and monocyte inflammatory networks in recent-onset schizophrenia patients involves both pro- and anti-inflammatory forces

We recently described a pro-inflammatory gene expression signature in the monocytes of 60% of patients with recent-onset schizophrenia (SCZ). Here we investigated whether the T-cell system is also in a pro-inflammatory state. A detailed fluorescence-activated cell sorting (FACS) analysis, e.g. of CD3+CD25+ T cells, IFN-γ+, IL-4+, IL-17A+ (CD4+) lymphocytes and CD4+CD25highFoxP3+ regulatory T cells, was performed on peripheral blood of 26 patients with recent-onset SCZ (in 19 of whom the inflammatory gene expression signature of the monocyte had been determined) and in age-/gender-matched healthy controls. Various relevant T-cell cytokines, e.g. sCD25, IFN-γ, IL-17A and IL-4, were measured in serum by a multiplex assay. We detected: (a) not only higher percentages of pro-inflammatory-prone monocytes, activated CD3+CD25+ T cells and pro-inflammatory Th17 cells in patients, but also higher percentages of anti-inflammatory CD4+CD25highFoxP3+ regulatory T cells and IL-4+ lymphocytes; (b) that this activated T-cell set point was reflected in significantly raised serum levels of sCD25; (c) that the up-regulation of IL-4+-containing lymphocytes was predominantly found in patients characterized by a monocyte pro-inflammatory set point; and (d) that regulatory T-cell and Th17-cell numbers were higher in patients irrespective of the pro-inflammatory state of the monocytes. Our data do not support the concept that the T-cell system is in a simple pro-inflammatory state in recent-onset SCZ, but do show that the monocyte and T-cell networks are activated and involve both pro- and anti-inflammatory forces. This suggests control within an activated inflammatory system.

Immune and Neuroimmune Alterations in Mood Disorders and Schizophrenia

A large number of publications over the past 20 years have indicated that immune system function is altered in schizophrenia and mood disorder patients. This chapter reviews the evidence, which suggests that a proinflammatory state of the cytokine network induces psychopathologic symptoms and may be involved in the pathogenesis and pathophysiology of these major mental illnesses. The authors also present recent data, which relates immune activation to present theories on the influence of activated immune cells in altering brain function. They also focus on the role of the environment in immune activation and on the role of the microbiome and gut flora. Increased understanding of such factors could help in the development of novel treatment strategies and improved clinical management of mental disorders.

The effect of antipsychotic medication on facial affect recognition in schizophrenia: A review

Patients with schizophrenia suffer from impairments in facial affect recognition and social functioning. Since antipsychotic medication affects different areas in the brain, they may also affect target areas involved in emotional processing mechanisms. In this article, we review the findings of the effect of antipsychotic medication on facial affect recognition in schizophrenia. We searched PubMed for articles in English with the keywords schizophrenia, facial, affect, emotion, antipsychotic and medication, published till January 2008. Eight relevant articles were found describing original studies. No substantial improvements in facial affect recognition were found after treatment with either typical or atypical antipsychotic drugs. Facial affect recognition was not related to neuropsychological functioning, and it was unclear whether improvement of symptom severity was related to performance on the facial affect recognition tasks. It is recommended that future research should focus on measuring social skills and social functioning more directly, and by investigating the effects of additional behavioural treatments on facial affect recognition and social functioning relative to treatment with antipsychotic medication alone.

BIOMARKERS OF NEUROLOGICAL AND PSYCHIATRIC DISEASE

A large number of publications over the past 20 years have indicated that immune system function is altered in schizophrenia and mood disorder patients. This chapter reviews the evidence, which suggests that a proinflammatory state of the cytokine network induces psychopathologic symptoms and may be involved in the pathogenesis and pathophysiology of these major mental illnesses. The authors also present recent data, which relates immune activation to present theories on the influence of activated immune cells in altering brain function. They also focus on the role of the environment in immune activation and on the role of the microbiome and gut flora. Increased understanding of such factors could help in the development of novel treatment strategies and improved clinical management of mental disorders.

Serum brain-derived neurotrophic factor level in relation to illness severity and episode duration in patients with major depression

BACKGROUND Since there are few data on the possible association between BDNF levels and characteristics of major depression, the present study assesses brain-derived neurotrophic factor (BDNF) levels in three drug-free patient samples, and explores whether episode duration, and severity correlate with serum BDNF levels. METHOD Serum BDNF levels were measured in 42 drug-free patients with major depression. The duration of the index episode and the presence of psychotic features were assessed with the Schedule for Affective Disorders and Schizophrenia, and the severity of depression was measured with the 17-item Hamilton Rating Scale for Depression. The sample was divided into three groups: severely depressed inpatients without psychotic features, severely depressed inpatients with psychotic features, and moderately depressed outpatients. RESULTS Mean serum BDNF level in the total sample was 18.0 ± 2.8 ng/ml, with no significant difference between the three patient samples (F = 1.80, df = 2, p = 0.18). Mean serum BDNF level was significantly lower in patients with an index episode over one year, compared with patients who had a shorter index episode (F = 4.90, df = 1, p = 0.033). CONCLUSION These data show that patients with a long index episode have significantly lower serum BDNF levels. We found no influence of the presence of psychotic features and severity of depression on serum BDNF levels.

Diurnal cortisol patterns of young male patients with schizophrenia

Aims:  It has been suggested that schizophrenic patients are more vulnerable to stress than healthy persons, and that stressors can trigger a psychotic episode or worsen symptoms. The biological system often studied in relation to stress is the hypothalamic–pituitary–adrenal (HPA) axis, which controls the release of cortisol. We investigated whether the diurnal basal activity of the HPA axis differed between young male patients with schizophrenia and healthy controls.

Marked reduction of AKT1 expression and deregulation of AKT1-associated pathways in peripheral blood mononuclear cells of schizophrenia patients

Background Recent studies have suggested that deregulated AKT1 signaling is associated with schizophrenia. We hypothesized that if this is indeed the case, we should observe both decreased AKT1 expression as well as deregulation of AKT1 regulated pathways in Peripheral Blood Mononuclear Cells (PBMCs) of schizophrenia patients. Objectives To examine PBMC expression levels of AKT1 in schizophrenia patients versus controls, and to examine whether functional biological processes in which AKT1 plays an important role are deregulated in schizophrenia patients. Methods/Results A case-control study, investigating whole-genome PBMC gene expression in male, recent onset (<5 years) schizophrenia patients (N = 41) as compared to controls (N = 29). Genes, differentially expressed between patients and controls were identified using ANOVA with Benjamini-Hochberg correction (false discovery rate (FDR) = 0.05). Functional aspects of the deregulated set of genes were investigated with the Ingenuity Pathway Analysis (IPA) Software Tool. We found significantly decreased PBMC expression of AKT1 (p<0.001, t = −4.25) in the patients. AKT1 expression was decreased in antipsychotic-free or -naive patients (N = 11), in florid psychotic (N = 20) and in remitted (N = 21) patients. A total of 1224 genes were differentially expressed between patients and controls (FDR = 0.05). Functional analysis of the entire deregulated gene set indicated deregulated canonical pathways involved in a large number of cellular processes: immune system, cell adhesion and neuronal guidance, neurotrophins and (neural) growth factors, oxidative stress and glucose metabolism, and apoptosis and cell-cycle regulation. Many of these processes are associated with AKT1. Conclusions We show significantly decreased PBMC gene expression of AKT1 in male, recent-onset schizophrenia patients. Our observations suggest that decreased PBMC AKT1 expression is a stable trait in recent onset, male schizophrenia patients. We identified several AKT related cellular processes which are potentially affected in these patients, a majority of which play a prominent role in current schizophrenia hypotheses.

Cardiovascular variability during treatment with haloperidol, olanzapine or risperidone in recent-onset schizophrenia

Abstract This study aimed to investigate the effects of treatment with haloperidol, olanzapine and risperidone on cardiovascular variability in patients with recent-onset schizophrenia by means of spectral analysis. Unmedicated patients (n = 18) had a higher mean heart rate and a tendency for a lower high-frequency power of heart rate variability than healthy control subjects (n = 57), indicating a decreased cardiac vagal control in unmedicated patients with schizophrenia. Patients treated with haloperidol (n = 10) showed significantly lower low-frequency power of heart rate and systolic blood pressure variability compared with olanzapine-treated patients, suggesting that haloperidol attenuated sympathetic functioning. On the contrary, olanzapine-treated patients (n = 10) showed the highest power in the low-frequency range of heart rate and systolic blood pressure variability, suggesting an increased sympathetic cardiac functioning. No significant effects of risperidone (n = 13) were found. None of the antipsychotic agents differed in their parasympathetic cardiovascular effects. We conclude that young, unmedicated patients with schizophrenia differed from controls in their parasympathetic functioning, but the antipsychotic agents haloperidol, risperidone and olanzapine induced only minor cardiovascular side effects.

Towards a blood-based diagnostic panel for bipolar disorder

BACKGROUND Bipolar disorder (BD) is a costly, devastating and life shortening mental disorder that is often misdiagnosed, especially on initial presentation. Misdiagnosis frequently results in ineffective treatment. We investigated the utility of a biomarker panel as a diagnostic test for BD. METHODS AND FINDINGS We performed a meta-analysis of eight case-control studies to define a diagnostic biomarker panel for BD. After validating the panel on established BD patients, we applied it to undiagnosed BD patients. We analysed 249 BD, 122 pre-diagnostic BD, 75 pre-diagnostic schizophrenia and 90 first onset major depression disorder (MDD) patients and 371 controls. The biomarker panel was identified using ten-fold cross-validation with lasso regression applied to the 87 analytes available across the meta-analysis studies. We identified 20 protein analytes with excellent predictive performance [area under the curve (AUC)⩾0.90]. Importantly, the panel had a good predictive performance (AUC 0.84) to differentiate 12 misdiagnosed BD patients from 90 first onset MDD patients, and a fair to good predictive performance (AUC 0.79) to differentiate between 110 pre-diagnostic BD patients and 184 controls. We also demonstrated the disease specificity of the panel. CONCLUSIONS An early and accurate diagnosis has the potential to delay or even prevent the onset of BD. This study demonstrates the potential utility of a biomarker panel as a diagnostic test for BD.