Interleukin 1 receptor antagonist and soluble tumor necrosis factor receptor 1 are associated with general severity and psychotic symptoms in schizophrenia and bipolar disorder

Peripheral inflammation is associated with impaired sadness recognition in euthymic bipolar patients

BACKGROUND

Inflammation impairs cognitive function in healthy individuals and people with psychiatric disorders, such as bipolar disorder (BD). This effect may also impact emotion recognition, a fundamental element of social cognition. Our study aimed to investigate the relationships between pro-inflammatory cytokines and emotion recognition in euthymic BD patients and healthy controls (HCs).

METHODS

We recruited forty-four euthymic BD patients and forty healthy controls (HCs) and measured their inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α. We applied validated cognitive tasks, the Wisconsin Card-Sorting Test (WCST) and Continuous Performance Test (CPT), and a social cognitive task for emotion recognition, Diagnostic Analyses of Nonverbal Accuracy, Taiwanese Version (DANVA-2-TW). We analyzed the relationships between cytokines and cognition and then explored possible predictive factors of sadness recognition accuracy.

RESULTS

Regarding pro-inflammatory cytokines, TNF-α was elevated in euthymic BD patients relative to HCs. In euthymic BD patients only, higher TNF-α levels were associated with lower accuracy of sadness recognition. Regression analysis revealed that TNF-α was an independent predictive factor of sadness recognition in patients with euthymic BD when neurocognition was controlled for.

CONCLUSIONS

We demonstrated that enhanced inflammation, indicated by increased TNF-α, was an independent predictive factor of impaired sadness recognition in BD patients but not in HCs. Our findings suggested a direct influence of TNF-α on sadness recognition and indicated vulnerability to depression in euthymic BD patients with chronic inflammation.

The role of Toll-like receptors in neuropsychiatric disorders: Immunopathology, treatment, and management

Neuropsychiatric disorders denote a broad range of illnesses involving neurology and psychiatry. These disorders include depressive disorders, anxiety, schizophrenia, bipolar disorder, attention deficit hyperactivity disorder, autism spectrum disorders, headaches, and epilepsy. In addition to their main neuropathology that lies in the central nervous system (CNS), lately, studies have highlighted the role of immunity and neuroinflammation in neuropsychiatric disorders. Toll-like receptors (TLRs) are innate receptors that act as a bridge between the innate and adaptive immune systems via adaptor proteins (e.g., MYD88) and downstream elements; TLRs are classified into 13 families that are involved in normal function and illnesses of the CNS. TLRs expression affects the course of neuropsychiatric disorders, and is influenced during their pharmacotherapy; For example, the expression of multiple TLRs is normalized during the major depressive disorder pharmacotherapy. Here, the role of TLRs in neuroimmunology, treatment, and management of neuropsychiatric disorders is discussed. We recommend longitudinal studies to comparatively assess the cell-type-specific expression of TLRs during treatment, illness progression, and remission. Also, further research should explore molecular insights into TLRs regulation and related pathways.

Migraine and the microbiota. Can probiotics be beneficial in its prevention? - a narrative review

Migraine is a recurrent disease of the central nervous system that affects an increasing number of people worldwide causing a continuous increase in the costs of treatment. The mechanisms underlying migraine are still unclear but recent reports show that people with migraine may have an altered composition of the intestinal microbiota. It is well established that the gut-brain axis is involved in many neurological diseases, and probiotic supplementation may be an interesting treatment option for these conditions. This review collects data on the gastrointestinal and oral microbiota in people suffering from migraine and the use of probiotics as a novel therapeutic approach in its treatment.

Intestinal permeability and low-grade chronic inflammation in schizophrenia: A multicentre study on biomarkers. Rationale, objectives, protocol and preliminary results

BACKGROUND

Altered intestinal permeability and low-grade chronic inflammation disrupt the integrity of the blood-brain barrier (microbiota-gut-brain axis), probably playing a role in the pathophysiology of schizophrenia-spectrum disorders. However, studies assessing the microbiota-gut-brain axis are inconsistent. This article describes the rationale, objectives, protocol, and presents descriptive results for a new project.

METHODS

The sample of this study came from an observational, cross-sectional and multisite study including four centers in Spain (PI17/00246) recruiting adult patients with DSM-5 schizophrenia-spectrum disorders at any stage of the disease. The aims of the project are to assess the interrelation between intestinal permeability and low-grade chronic inflammation in schizophrenia-spectrum disorders and the role of peripheral biomarkers, diet, exercise, metabolic syndrome, disease severity and functioning as well as cognition. Assessments included the following variables: (1) anthropometric, (2) intestinal permeability, diet, and physical exercise, (3) clinical and functional, (4) neuropsychological and cognitive reserve, and (5) peripheral biomarkers from blood.

RESULTS

A total of 646 patients were enrolled (257, 39.7% female). Mean age was 43.2±13.6 years, illness duration 15.1±11.5 years. 55.8% consumed tobacco. Positive PANSS score was 13.68±6.55, and 20.38±8.69 in the negative symptoms. CGI was 4.16±2.22 and GAF was 60.00±14.84.

CONCLUSION

The results obtained by this project are expected to contribute toward the understanding of the physiopathology of schizophrenia-spectrum disorders. This will likely aid to personalize treatments in real-world clinical practice, potentially including variables related to intestinal permeability and inflammation.

Increased prefrontal cortical cells positive for macrophage/microglial marker CD163 along blood vessels characterizes a neuropathology of neuroinflammatory schizophrenia

Transcript levels of cytokines and SERPINA3 have been used to define a substantial subset (40%) of individuals with schizophrenia with elevated inflammation and worse neuropathology in the dorsolateral prefrontal cortex (DLPFC). In this study, we tested if inflammatory proteins are likewise related to high and low inflammatory states in the human DLFPC in people with schizophrenia and controls. Levels of inflammatory cytokines (IL6, IL1β, IL18, IL8) and a macrophage marker (CD163 protein) were measured in brains obtained from the National Institute of Mental Health (NIMH) (N = 92). First, we tested for diagnostic differences in protein levels overall, then we determined the percentage of individuals that could be defined as "high" inflammation using protein levels. IL-18 was the only cytokine to show increased expression in schizophrenia compared to controls overall. Interestingly, two-step recursive clustering analysis showed that IL6, IL18, and CD163 protein levels could be used as predictors of "high and low" inflammatory subgroups. By this model, a significantly greater proportion of schizophrenia cases (18/32; 56.25%; SCZ) were identified as belonging to the high inflammatory (HI) subgroup compared to control cases (18/60; 30%; CTRL) [χ2(1) = 6.038, p = 0.014]. When comparing across inflammatory subgroups, IL6, IL1β, IL18, IL8, and CD163 protein levels were elevated in both SCZ-HI and CTRL-HI compared to both low inflammatory subgroups (all p < 0.05). Surprisingly, TNFα levels were significantly decreased (-32.2%) in schizophrenia compared to controls (p < 0.001), and were most diminished in the SCZ-HI subgroup compared to both CTRL-LI and CTRL-HI subgroups (p < 0.05). Next, we asked if the anatomical distribution and density of CD163+ macrophages differed in those with schizophrenia and high inflammation status. Macrophages were localized to perivascular sites and found surrounding small, medium and large blood vessels in both gray matter and white matter, with macrophage density highest at the pial surface in all schizophrenia cases examined. A higher density of CD163+ macrophages, that were also larger and more darkly stained, was found in the SCZ-HI subgroup (+154% p < 0.05). We also confirmed the rare existence of parenchymal CD163+ macrophages in both high inflammation subgroups (schizophrenia and controls). Brain CD163+ cell density around blood vessels positively correlated with CD163 protein levels. In conclusion, we find a link between elevated interleukin cytokine protein levels, decreased TNFα protein levels, and elevated CD163+ macrophage densities especially along small blood vessels in those with neuroinflammatory schizophrenia.

Research and Diagnostic Algorithmic Rules (RADAR) for mood disorders, recurrence of illness, suicidal behaviours, and the patient's lifetime trajectory

The top-down Diagnostic and Statistical Manual/International Statistical Classification of Diseases categories of mood disorders are inaccurate, and their dogmatic nature precludes both deductive (as indisputable) and inductive (as top-down) remodelling of case definitions. In trials, psychiatric rating scale scores employed as outcome variables are invalid and rely on folk psychology-like narratives. Using machine learning techniques, we developed a new precision nomothetic model of mood disorders with a recurrence of illness (ROI) index, a new endophenotype class, namely Major Dysmood Disorder (MDMD), characterised by increased ROI, a more severe phenome, and more disabilities. Nonetheless, our previous studies did not compute Research and Diagnostic Algorithmic Rules (RADAR) to diagnose MDMD and score ROI, lifetime (LT), and current suicidal behaviours, as well as the phenome of mood disorders. Here, we provide rules to compute bottom-up RADAR scores for MDMD, ROI, LT and current suicidal ideation and attempts, the phenome of mood disorders, and the lifetime trajectory of mood disorder patients from a family history of mood disorders and substance abuse to adverse childhood experiences, ROI, and the phenome. We also demonstrate how to plot the 12 major scores in a single RADAR graph, which displays all features in a two-dimensional plot. These graphs allow the characteristics of a patient to be displayed as an idiomatic fingerprint, allowing one to estimate the key traits and severity of the illness at a glance. Consequently, biomarker research into mood disorders should use our RADAR scores to examine pan-omics data, which should be used to enlarge our precision models and RADAR graph.

Glial-Neuronal Interaction in Synapses: A Possible Mechanism of the Pathophysiology of Bipolar Disorder

Bipolar disorder (BD) is a severe and chronic psychiatric disorder that affects approximately 1-4% of the world population and is characterized by recurrent episodes of mania or hypomania and depression. BD is also associated with illnesses marked by immune activation, such as metabolic syndrome, obesity, type 2 diabetes mellitus, and cardiovascular diseases. Indeed, a connection has been suggested between neuroinflammation and peripheral inflammatory markers in the pathophysiology of BD, which can be associated with the modulation of many dysfunctional processes, including synaptic plasticity, neurotransmission, neurogenesis, neuronal survival, apoptosis, and even cognitive/behavioral functioning. Rising evidence suggests that synaptic dysregulations, especially glutamatergic system dysfunction, are directly involved in mood disorders. It is becoming clear that dysregulations in connection and structural changes of glial cells play a central role in the BD pathophysiology. This book chapter highlighted the latest findings that support the theory of synaptic dysfunction in BD, providing an overview of the alterations in neurotransmitters release, astrocytic uptake, and receptor signaling, as well as the role of inflammation on glial cells in mood disorders. Particular emphasis is given to the alterations in presynaptic and postsynaptic neurons and glial cells, all cellular elements of the "tripartite synapse," compromising the neurotransmitters system, excitatory-inhibitory balance, and neurotrophic states of local networks in mood disorders. Together, these studies provide a foundation of knowledge about the exact role of the glial-neuronal interaction in mood disorders.

The Role of Gut Dysbiosis in the Pathophysiology of Neuropsychiatric Disorders

Mounting evidence shows that the complex gut microbial ecosystem in the human gastrointestinal (GI) tract regulates the physiology of the central nervous system (CNS) via microbiota and the gut-brain (MGB) axis. The GI microbial ecosystem communicates with the brain through the neuroendocrine, immune, and autonomic nervous systems. Recent studies have bolstered the involvement of dysfunctional MGB axis signaling in the pathophysiology of several neurodegenerative, neurodevelopmental, and neuropsychiatric disorders (NPDs). Several investigations on the dynamic microbial system and genetic-environmental interactions with the gut microbiota (GM) have shown that changes in the composition, diversity and/or functions of gut microbes (termed "gut dysbiosis" (GD)) affect neuropsychiatric health by inducing alterations in the signaling pathways of the MGB axis. Interestingly, both preclinical and clinical evidence shows a positive correlation between GD and the pathogenesis and progression of NPDs. Long-term GD leads to overstimulation of hypothalamic-pituitary-adrenal (HPA) axis and the neuroimmune system, along with altered neurotransmitter levels, resulting in dysfunctional signal transduction, inflammation, increased oxidative stress (OS), mitochondrial dysfunction, and neuronal death. Further studies on the MGB axis have highlighted the significance of GM in the development of brain regions specific to stress-related behaviors, including depression and anxiety, and the immune system in the early life. GD-mediated deregulation of the MGB axis imbalances host homeostasis significantly by disrupting the integrity of the intestinal and blood-brain barrier (BBB), mucus secretion, and gut immune and brain immune functions. This review collates evidence on the potential interaction between GD and NPDs from preclinical and clinical data. Additionally, we summarize the use of non-therapeutic modulators such as pro-, pre-, syn- and post-biotics, and specific diets or fecal microbiota transplantation (FMT), which are promising targets for the management of NPDs.

Psychotic features, particularly mood incongruence, as a hallmark of severity of bipolar I disorder

BACKGROUND

The occurrence of psychotic features within mood episodes in patients with bipolar I disorder (BD I) has been associated in some studies with a more severe clinical and socio-professional profile. In contrast, other studies establishing the associations of psychotic features in BD I, and in particular of mood-congruent (MC) and mood-incongruent (MI) features, with clinical characteristics have yielded contradictory results. However, many pre-existing studies have been affected by serious methodological limitations. Using a sample of thoroughly assessed patients with BD I our aims were to: (1) establish the proportion of those with MI and MC features, and (2) compare BD I patients with and without psychotic features as well as those with MI to those with MC features on a wide array of socio-demographic and clinical characteristics including course, psychiatric comorbidity and treatment.

METHODS

A sample of 162 treated patients with BD I (60.5% female, mean age = 41.4 (s.d: 10.2) years) was recruited within a large family study of mood disorders. Clinical, course and treatment characteristics relied on information elicited through direct diagnostic interviews, family history reports and medical records.

RESULTS

(1) A total of 96 patients (59.3%) had experienced psychotic features over their lifetime. Among them, 44.8% revealed MI features at least once in their lives. (2) Patients with psychotic features were much less likely to be professionally active, revealed alcohol abuse more frequently and used health care, particularly inpatient treatment, more frequently than those without psychotic features. Within patients with psychotic symptoms, those with MI features showed more clinical severity in terms of a higher likelihood of reporting hallucinations, suicidal attempts and comorbid cannabis dependence.

CONCLUSION

Our data provide additional support for both the distinction between BD-I with and without psychotic features as well as the distinction between MI and MC psychotic features. The more severe course of patients with psychotic features, and particularly those with MI psychotic features, highlights the need for thorough psychopathological evaluations to assess the presence of these symptoms to install appropriate treatment.

The interplay between the gut-brain axis and the microbiome: A perspective on psychiatric and neurodegenerative disorders

What is the effect of our gut microbial flora on brain? Does the gut microbiome have any role in the causation of psychiatric and neurodegenerative diseases? Does the effect of gut microbiota traverse the gut-brain axis? Questions like these have captured the interest and imagination of the scientific community for quite some time now. Research in the quest for answers to these questions, to unravel the potential role of the microbiota inhabiting the gut in controlling brain functions, has progressed manifold over the last two decades. Although the possibility of microbiome as a key susceptibility factor for neurological disorders viz. Parkinson's disease, Alzheimer's disease, multiple sclerosis, and autism spectrum disorder has bolstered by an increase in the clinical and preclinical evidence, the field is still in its infancy. Given the fact that the diversity of the gut microbiota is affected by various factors including the diet and exercise, the interpretation of such data becomes all the more difficult. Also, such studies have been mostly conducted on animal models, so there is a need for randomized controlled trials in human subjects, corroborated by longitudinal studies, to establish if modulating the gut microbiota can unravel novel therapeutic interventions. Exploring the genomic, metagenomic and metabolomic data from clinical subjects with psychiatric and neurological diseases can prove to be a helpful guide in individual treatment selection.

Interleukin-1 receptor antagonist (IL-1RA) and interleukin-4 (IL-4) variable number of tandem repeat polymorphisms in schizophrenia and bipolar disorder: an association study in Turkish population

Background

Pro-inflammatory/anti-inflammatory cytokine imbalance in cerebrospinal fluid or plasma of schizophrenia (SCZ) and bipolar disorder (BD) patients has been documented over the last decade. We aim to examine the interleukin-1 receptor antagonist (IL-1RA) and IL-4 variable number of tandem repeat (VNTR) polymorphisms in SCZ and BD patients by comparing them with healthy controls.

Methods

Two hundred and thirty-four unrelated patients (127 patients with SCZ, 107 patients with BD) and 204 healthy controls were included. The Structured Clinical Interview for DSM-IV Axis I Disorders was used to confirm the diagnosis. In addition, the polymerase chain reaction technique was used to investigate IL-1RA and IL-4 VNTR polymorphisms.

Results

Our results showed that the distributions of IL-1RA and IL-4 genotype and the allele frequencies of SCZ or BD patients were not significantly different from the healthy control group. IL-1RA allele 2 homozygous genotype and IL-1RA allele 2 frequencies were non-significantly higher among SCZ patients than in controls.

Conclusions

Our study indicates that the IL-1RA and IL-4 VNTR polymorphisms are not considered risk factors for developing SCZ and BD among Turkish patients.

Metabolic phenotyping reveals a potential link between elevated faecal amino acids, diet and symptom severity in individuals with severe mental illness

The brain-gut axis is increasingly recognized as an important contributing factor in the onset and progression of severe mental illnesses such as schizophrenia spectrum disorders and bipolar disorder. This study investigates associations between levels of faecal metabolites identified using ¹H-NMR, clinical parameters, and dietary components of forty-two individuals diagnosed in a transdiagnostic approach to have severe mental illness. Faecal levels of the amino acids; alanine, leucine, and valine showed a significant positive correlation with psychiatric symptom severity as well as with dairy intake. Overall, this study proposes a diet-induced link between the brain-gut axis and the severity of psychiatric symptoms, which could be valuable in the design of novel dietary or therapeutic interventions to improve psychiatric symptoms.

Limited association between infections, autoimmune disease and genetic risk and immune activation in severe mental disorders

BACKGROUND

Low-grade inflammation may be part of the underlying mechanism of schizophrenia and bipolar disorder. We investigated if genetic susceptibility, infections or autoimmunity could explain the immune activation.

METHODS

Seven immune markers were selected based on indicated associations to severe mental disorders (IL-1Ra, sIL-2R, IL-18, sgp130, sTNFR-1, APRIL, ICAM-1) and measured in plasma of patients with schizophrenia (SCZ, N = 732) and bipolar spectrum disorders (BD, N = 460) and healthy controls (HC, N = 938). Information on rate of infections and autoimmune diseases were obtained from Norwegian national health registries for a twelve-year period. Polygenic risk scores (PRS) of SCZ and BD were calculated from genome-wide association studies. Analysis of covariance were used to test effects of infection rate, autoimmune disease and PRS on differences in immune markers between patients and HC.

RESULTS

Infection rate differed between all groups (BD > HC > SCZ, all p < 0.001) whereas autoimmune disease was more frequent in BD compared to SCZ (p = 0.004) and HC (p = 0.003). sIL-2R was positively associated with autoimmune disease (p = 0.001) and negatively associated with PRS of SCZ (p = 0.006) across SCZ and HC; however, associations represented only small changes in the difference of sIL-2R levels between SCZ and HC.

CONCLUSION

There were few significant associations between rate of infections, autoimmune disease or PRS and altered immune markers in SCZ and BD, and the detected associations represented only small changes in the immune aberrations. The findings suggest that most of the low-grade inflammation in SCZ and BD is explained by other factors than the underlying PRS, autoimmunity and infection rates.

Pro-inflammatory cytokines and suicidal behavior among patients with bipolar I disorder

OBJECTIVE

Suicidal behavior and different mood states of bipolar I disorder (BD) have been shown to be associated with dysregulated proinflammatory cytokines. Only a few studies have examined the association between inflammation and SB in BD, and the association between proinflammatory cytokines, SB, and cognitive deficits in patients with BD remains unclear.

METHODS

77 patients with BD and 61 age-/sex-matched healthy controls were recruited. Patients were divided into two groups: with suicidal ideation (SI; n = 21) and no SI (n = 56). SI was defined by a score of ≥1 in item 10 of Montgomery Åsberg Depression Rating Scale. Levels of proinflammatory cytokines, including soluble interleukin-6 receptor (sIL-6R), soluble tumor necrosis factor-α receptor type 1 (sTNF-αR1), and C-reactive protein (CRP), were measured, and cognitive function was assessed using 2-back task and Go/No-Go task.

RESULTS

Patients with SI had higher levels of sTNF-αR1 than those without SI and the controls (p = .004). BD patients with or without a history of suicide attempt had higher levels of CRP than the controls. SI was associated with serum levels of sTNF-αR1 and IL-6sR, even after additionally controlling for working memory and inhibitory control (p < .05).

CONCLUSION

This study indicates that serum levels of sTNF-αR1 have distinct differences between BD patients with or without SI, and our findings strengthen the hypothesis of a link between suicidal behavior and neuro-inflammation pathophysiology in BD.

Quantitative detection of methylated SOCS-1 in schizophrenia and bipolar disorder considering SOCS-1 -1478CA/del polymorphism and clinical parameters

BACKGROUND

We aimed to investigate the quantitative detection of methylated suppressor of cytokine signaling-1 (SOCS-1) in schizophrenia (SCZ) and bipolar disorder (BD), considering SOCS-1 -1478CA/del polymorphism and clinical parameters.

METHODS

Our research is a case-control study in which 114 patients with SCZ, 86 patients with BD, and 80 volunteers as a healthy group participated. Bisulfite-converted DNA samples were analyzed using the real-time quantitative methylation-specific PCR (qMS-PCR) method to measure the methylation level of the SOCS-1 gene. In addition, SOCS-1 -1478CA/del gene polymorphism was analyzed with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

When the SOCS-1 promoter methylation levels of SCZ and BD patients were compared with the control group, the methylation levels of SCZ and BD were significantly lower than the control group. An earlier age of illness onset was significantly related to the SOCS-1 promoter hypermethylation in DNA samples of SCZ patients. Again, SOCS-1 promoter hypermethylation was significantly associated with the higher Young Mania Rating Scale (YMRS) score in BD patients. While the SOCS-1 CA/CA genotype frequency was significantly higher in the control group than in the BD group, the del/del genotype was significantly related to a higher frequency of rapid cycling and a lower frequency of family history in the BD patient group.

CONCLUSION

In summary, the methylated SOCS-1 quantity in DNA samples of SCZ and BD patients were significantly lower than in control samples. Whereas the SOCS-1 -1478CA/del polymorphism was not related to SCZ, it may be associated with the BD.

Dynamics and correlations in multiplex immune profiling reveal persistent immune inflammation in male drug users after withdrawal

Drug withdrawal elicits immune responses that contribute to the development of withdrawal symptoms and relapse. The understanding of the immunologic dynamics after drug withdrawal is limited, precluding the finding of promising immune intervention measures. Here, we performed cytokine and multiplex immune profiling in heroin, methamphetamine (METH) and ephedrine users after withdrawal and identified the correlation between cytokines and other immune parameters. We showed that broad and strong inflammatory responses occurred at the early stage after drug withdrawal, and the inflammatory responses showed a downtrend with the extension of withdrawal time. Notably, immune dysregulation remained through and may last longer than 12 months after withdrawal in heroin and METH users. Our findings suggest that cytokines, immune cells, complement and immunoglobulin form a complex immune network that regulates immune responses after withdrawal. These data provide a reference for future scientific research and drug research and development.

Cognition-immune interactions between executive function and working memory, tumour necrosis factor-alpha (TNF-alpha) and soluble TNF receptors (sTNFR1 and sTNFR2) in bipolar disorder

OBJECTIVES

This study examined cognition-immune interactions, specifically executive function, working memory, peripheral levels of tumour necrosis factor-alpha (TNF-α), and soluble tumour necrosis factor receptors-1 and -2 (sTNFR1 and 2) levels in bipolar disorder (BD) patients in comparison with controls.

METHODS

Thirty-one BD participants and twenty-seven controls participated in the study. The neurocognitive assessment was performed through three of CogState Research Battery^TM tasks for executive function and working memory. Plasma levels of TNF-α, sTNFR1, and sTNFR2 were measured after overnight fasting. Sociodemographic data and symptom severity of depression and mania were assessed.

RESULTS

BD presented a significantly worse performance in the working memory task (p = .005) and higher levels of TNF-α (p = .043) in comparison to controls. A trend level of significance was found for sTNFR1 between groups (p = .082). Among BD participants, there were significant correlations between sTNFR2 and neurocognitive tasks (Groton Maze Learning Task: ρ = .54, p = .002; Set-Shifting Task: ρ = .37, p = .042; and the Two-Back Task: ρ = -.49, p = .005), and between sTNFR1 and mania, depression and anxiety symptoms (respectively ρ = .37, p = .038; ρ = -.38, p = .037; and ρ = .42, p = .002).

CONCLUSION

TNF-α and its receptors might be an important variable in cognitive impairment in BD. Future studies might focus on the development of anti-inflammatory therapeutic targets for cognitive dysfunction in BD.

The Perspectives of Early Diagnosis of Schizophrenia Through the Detection of Epigenomics-Based Biomarkers in iPSC-Derived Neurons

The lack of early diagnostic biomarkers for schizophrenia greatly limits treatment options that deliver therapeutic agents to affected cells at a timely manner. While previous schizophrenia biomarker research has identified various biological signals that are correlated with certain diseases, their reliability and practicality as an early diagnostic tool remains unclear. In this article, we discuss the use of atypical epigenetic and/or consequent transcriptional alterations (ETAs) as biomarkers of early-stage schizophrenia. Furthermore, we review the viability of discovering and applying these biomarkers through the use of cutting-edge technologies such as human induced pluripotent stem cell (iPSC)-derived neurons, brain models, and single-cell level analyses.

Nucks1 gene polymorphism rs823114 is associated with the positive symptoms and neurocognitive function of patients with schizophrenia in parts of southern China

Nuclear casein kinase and cyclin-dependent kinase substrate 1 (nucks1) are considered a potential susceptibility gene for certain neurological diseases, such as Parkinson's disease (PD). In our study, we genotyped three single nucleotide polymorphisms (SNPs) (rs4951261, rs823114 and rs951366) of the nucks1 gene in 774 schizophrenic patients and 819 healthy controls using the improved multiplex ligation detection reaction (imLDR) technique. Furthermore, we also studied the relationship between the above SNPs and the clinical psychiatric symptoms and neurocognitive function of the patients. Genotype distributions and allele frequencies of these SNPs showed no significant differences and were found between patients and healthy controls. However, in an analysis of the positive symptom score of rs823114 among male patients, we found that the score of the A/A genotype was lower than that of the G/A+G/G genotypes (P = 0.001, P(corr) = 0.003]. Additionally, we also found that among the female patients, G allele carriers with rs823114 had lower semantic fluency scores than subjects with the A/A genotype (P = 0.010, P(corr) = 0.030]. Our data show for the first time that rs823114 polymorphism of nucks1 may affect positive symptoms and neurocognitive function in patients with schizophrenia in parts of southern China.

Inflammatory signaling mechanisms in bipolar disorder

Bipolar disorder is a decidedly heterogeneous and multifactorial disease, with a high individual and societal burden. While not all patients display overt markers of elevated inflammation, significant evidence suggests that aberrant immune signaling contributes to all stages of the disease, and likely explains the elevated rates of comorbid inflammatory illnesses seen in this population. While individual systems have been intensely studied and targeted, a relative paucity of attention has been given to the interconnecting role of inflammatory signals therein. This review presents an updated overview of some of the most prominent pathophysiologic mechanisms in bipolar disorder, from mitochondrial, endoplasmic reticular, and calcium homeostasis, to purinergic, kynurenic, and hormonal/neurotransmitter signaling, showing inflammation to act as a powerful nexus between these systems. Several areas with a high degree of mechanistic convergence within this paradigm are highlighted to present promising future targets for therapeutic development and screening.

Anti-inflammatory Combination Therapy for the Treatment of Schizophrenia

BACKGROUND

Despite adequate antipsychotic treatment, most people with schizophrenia continue to exhibit persistent positive and negative symptoms and cognitive impairments. The current study was designed to examine the efficacy and safety of adjunctive anti-inflammatory combination therapy for these illness manifestations.

METHODS

Thirty-nine people with either Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, schizophrenia or schizoaffective disorder were entered into a 12-week double-blind, 2-arm, triple-dummy, placebo-controlled, randomized clinical trial: 19 were randomized to anti-inflammatory combination therapy and 20 were randomized to placebo. The Brief Psychiatric Rating Scale positive symptom item total score was used to assess positive symptom change, the Scale for the Assessment of Negative Symptoms total score was used to assess negative symptom change, the Calgary Depression Scale total score was used to assess depressive symptom change, and the MATRICS Consensus Cognitive Battery was used to assess neuropsychological test performance.

RESULTS

There was a significant time effect for Brief Psychiatric Rating Scale positive symptom item score (t226 = -2.66, P = 0.008), but the treatment (t54=1.52, P = 0.13) and treatment × time (t223 = 0.47, P = 0.64) effects were not significant. There were no significant time (t144 = 0.53, P = 0.72), treatment (t58=0.48, P = 0.63), or treatment × time (t143 = -0.20, P = 0.84) effects for the Scale for the Assessment of Negative Symptoms total score; or for any of the other symptom measures. There were no significant group differences in the change in the MATRICS Consensus Cognitive Battery composite score over the course of the study (F1,26=2.20, P = 0.15).

CONCLUSIONS

The study results suggest that there is no significant benefit of combined anti-inflammatory treatment for persistent positive symptoms or negative symptoms or cognitive impairments (clinicaltrials.gov trial number: NCT01514682).

Towards precision medicine: What are the stratification hypotheses to identify homogeneous inflammatory subgroups

Diverse lines of research testify a link, presumably causal, between immune dysregulation and the development, course and clinical outcome of psychiatric disorders. However, there is a large heterogeneity among the patients' individual immune profile and this heterogeneity prevents the development of precise diagnostic tools and the identification of therapeutic targets. The aim of this review was to delineate possible subgroups of patients on the basis of clinical dimensions, investigating whether they could lead to particular immune signatures and tailored treatments. We discuss six clinical entry points; genetic liability to immune dysregulation, childhood maltreatment, metabolic syndrome, cognitive dysfunction, negative symptoms and treatment resistance. We describe the associated immune signature and outline the effects of anti-inflammatory drugs so far. Finally, we discuss advantages of this approach, challenges and future research directions.

Doxycycline reverses cognitive impairment, neuroinflammation and oxidative imbalance induced by D-amphetamine mania model in mice: A promising drug repurposing for bipolar disorder treatment?

Immune-inflammatory mechanisms are involved in the pathophysiology of bipolar disorder. Tetracyclines present neuroprotective actions based on their anti-inflammatory and microglia suppressant effects. Doxycycline (DOXY) is a tetracycline that demonstrates a better usage profile with protective actions against inflammation and CNS injury. Here, we investigated the effects of DOXY against behavioral, neuroinflammatory, and pro-oxidative changes induced by the d-amphetamine mania model. Adult mice were given d-amphetamine 2.0 mg/kg or saline for 14 days. Between days 8 and 14, received lithium, DOXY (25 or 50 mg/kg), or their combination (lithium+DOXY) on both doses. We collected the brain areas prefrontal cortex (PFC), hippocampus, and amygdala to evaluate inflammatory and oxidative alterations. D-amphetamine induced hyperlocomotion and impairment in recognition and working memory. Lithium reversed hyperlocomotion but could not restore cognitive alterations. DOXY alone (at both doses) or combined with lithium reversed d-amphetamine-induced cognitive changes. DOXY, better than lithium, reversed the d-amphetamine-induced rise in TNFα, MPO, and lipid peroxidation. DOXY reduced the hippocampal expression of Iba1 (a marker of microglial activation), inducible nitric oxide synthase (iNOS), and nitrite. Combined with lithium, DOXY increased the phosphorylated (inactivated) form of GSK3β (Ser9). Therefore, DOXY alone or combined with lithium reversed cognitive impairment and neuroinflammation induced by the mice's d-amphetamine model. This study points to DOXY as a promising adjunctive tool for bipolar disorder treatment focused on cognition and neuroimmune changes. Our data provide the first rationale for clinical trials investigating DOXY therapeutic actions in bipolar disorder mania.

Endothelial dysfunction in neuroprogressive disorders-causes and suggested treatments

BACKGROUND

Potential routes whereby systemic inflammation, oxidative stress and mitochondrial dysfunction may drive the development of endothelial dysfunction and atherosclerosis, even in an environment of low cholesterol, are examined.

MAIN TEXT

Key molecular players involved in the regulation of endothelial cell function are described, including PECAM-1, VE-cadherin, VEGFRs, SFK, Rho GEF TRIO, RAC-1, ITAM, SHP-2, MAPK/ERK, STAT-3, NF-κB, PI3K/AKT, eNOS, nitric oxide, miRNAs, KLF-4 and KLF-2. The key roles of platelet activation, xanthene oxidase and myeloperoxidase in the genesis of endothelial cell dysfunction and activation are detailed. The following roles of circulating reactive oxygen species (ROS), reactive nitrogen species and pro-inflammatory cytokines in the development of endothelial cell dysfunction are then described: paracrine signalling by circulating hydrogen peroxide, inhibition of eNOS and increased levels of mitochondrial ROS, including compromised mitochondrial dynamics, loss of calcium ion homeostasis and inactivation of SIRT-1-mediated signalling pathways. Next, loss of cellular redox homeostasis is considered, including further aspects of the roles of hydrogen peroxide signalling, the pathological consequences of elevated NF-κB, compromised S-nitrosylation and the development of hypernitrosylation and increased transcription of atherogenic miRNAs. These molecular aspects are then applied to neuroprogressive disorders by considering the following potential generators of endothelial dysfunction and activation in major depressive disorder, bipolar disorder and schizophrenia: NF-κB; platelet activation; atherogenic miRs; myeloperoxidase; xanthene oxidase and uric acid; and inflammation, oxidative stress, nitrosative stress and mitochondrial dysfunction.

CONCLUSIONS

Finally, on the basis of the above molecular mechanisms, details are given of potential treatment options for mitigating endothelial cell dysfunction and activation in neuroprogressive disorders.

Higher Serum C-Reactive Protein Levels in Catatonic Patients: A Comparison to Non-catatonic Patients and Healthy Controls

Catatonia is a psychomotor syndrome defined by a constellation of predominantly motor symptoms. The aim of the present study was to determine whether recently admitted psychiatric patients with catatonia exhibited higher serum C-reactive protein (hs-CRP) levels compared to non-catatonic psychiatric patients and healthy controls (HCs). Recently admitted psychiatric patients were screened and evaluated for the catatonia syndrome using the Bush-Francis Catatonia Rating Scale and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). The study sample was formed by 150 individuals (39 male and 111 female), including 51 catatonic patients, 55 non-catatonic patients, and 44 HCs. Serum hs-CRP levels were processed with the enzyme-linked immunosorbent assay. Serum levels of creatine kinase (CK), adrenocorticotropic hormone (ACTH), immunoglobulin G (IgG), complement component 3 (C3), and complement component 4 (C4) were also determined. There was a significantly higher percentage of patients with high inflammatory levels (hs-CRP > 3000ng/ml) in the catatonic (43.1%) than in the non-catatonic (14.5%) or HCs group (9.1%) (χ 2 =18.9, P < .001). Logistic regression showed that catatonic patients had significantly higher hs-CRP levels compared to non-catatonic patients even after controlling for other clinical and laboratory variables (OR = 3.52, P = .015, 95% CI 1.28-9.79). Multiple linear regression analysis revealed that log-transformed hs-CRP was independently predicted by body mass index and log-transformed C4, ACTH, and Cortisol in catatonic patients. Findings of the present study suggest that catatonia is specifically linked to a higher level of systemic inflammation, not merely attributable to the overall psychopathology, or alterations in the stress level and complement system.

Probiotics and prebiotics: focus on psychiatric disorders - a systematic review

CONTEXT

The gut-brain axis and microbial dysbiosis may play a role in psychiatric diseases. In this view, the gut microbiota has been considered a potential therapeutic target using probiotics and prebiotics.

OBJECTIVE

This systematic review aims to find the existing clinical evidence that may justify the use of probiotics or prebiotics in psychiatric patients.

DATA SOURCES

PRISMA guidelines were followed for a systematic literature review of randomized controlled trials that assessed the effect of prebiotics or probiotics in patients diagnosed with a classified psychiatric disorder.

DATA EXTRACTION

From a total of 212 studies screened, 11 were included in the final systematic review. Quality assessment of the included trials was assessed by the Jadad scale.

RESULTS

Probiotics seem to offer some benefit in major depressive disorder and Alzheimer's disease. One study showed that probiotics reduced rehospitalization in patients with acute mania. In autism spectrum disorders, the results were controversial; however a single study found that early administration of probiotics showed a preventive role. No benefits were found for patients with schizophrenia. In most studies, no major adverse effects were reported.

CONCLUSIONS

Although recent findings in specific psychiatric disorders are encouraging, the use of prebiotics and probiotics in clinical practice stills lacks sufficiently robust evidence.

TNF-α and its soluble receptors mediate the relationship between prior severe mood episodes and cognitive dysfunction in euthymic bipolar disorder

BACKGROUND

Bipolar disorder (BD) is one of the most disabling mental health conditions in the world. Symptoms of cognitive impairment in BD contribute directly to occupational and social deficiencies and are very difficult to treat. Converging evidence suggests that BD patients have increased peripheral markers of inflammation. The hypothesis of neuroprogression in BD postulates that cognitive deficits develop over the course of the illness and are influenced by prior severe mood episodes, leading to wear-and-tear on the brain- however, there exists a paucity of data statistically testing a mediating role of immune molecules in cognitive dysfunction in BD.

METHODS

This is a cross-sectional study. We measured serum levels of tumor necrosis factor alpha (TNF-α), and soluble (s) TNF receptors one and two (sTNF-R1 and sTNF-R2) in 219 euthymic BD patients and 52 Healthy Controls (HCs). Structural equation modeling (SEM) was used for the primary purpose of assessing whether TNF markers (measured by the multiple indicators TNF-α, sTNF-R1 and sTNF-R2) mediate the effect or number of prior severe mood episodes (number of prior psychiatric hospitalizations) on cognitive performance.

RESULTS

BD and HC groups did not differ on circulating levels of TNF molecules in the present study. However, we found higher sTNF-R1 concentration in 'late-stage' BD illness (>1 prior psychiatric hospitalization) compared to those in early stage illness. In the subsequent SEM, we found that the model fits the data acceptably (Chi-square = 49.2, p = 0.3), and had a 'close fit' (RMSEA = 0.02, PCLOSE = 0.9). Holding covariates constant (age, sex, premorbid IQ, education, and race), we found that the standardized indirect effect was significant, p = 0.015, 90%CI [-0.07, -0.01], indicating that the estimated model was consistent with peripheral TNF markers partially mediating a causal effect of severe mood episodes on executive function.

CONCLUSIONS

Our results indicate that circulating levels of TNF molecules partially mediate the relationship between prior severe mood episodes and executive function in BD. These results may implicate TNF variables in the neuroprogressive course of BD and could point to novel interventions for cognition.

Decreased IL-1β-induced CCL20 response in human iPSC-astrocytes in schizophrenia: Potential attenuating effects on recruitment of regulatory T cells

Schizophrenia (SCZ) is a severe mental disorder with a high heritability. Although its pathophysiology is mainly unknown, dysregulated immune activation and inflammation have recently emerged as possible candidates in the underlying mechanisms of SCZ. Previous studies suggest that aberrant inflammasome activation, glia dysregulation, and brain inflammation may be involved in the pathophysiology of the disorder. Here, we studied the effects of inflammatory modulation on human induced pluripotent stem cell (iPSC)-derived astrocytes generated from SCZ patients and healthy controls (CTRL). Inflammasome activation was mimicked by short-term IL-1β exposure, and gene expression were measured with high-coverage RNA-Seq to ensure a global characterization of the transcriptional effects of the treatment. IL-1β exposure modulated several pathways involved in innate immune responses, cell cycle regulation, and metabolism in both SCZ and CTRL astrocytes. Significant differences were found in the expression of HILPDA and CCL20 genes, both of which had reduced up-regulation upon IL-1β treatment in SCZ astrocytes compared to CTRL astrocytes. CCL20 data were further validated and confirmed using qPCR, ELISA, and regulatory T lymphocyte (T_reg) migration assays. Additionally, we found significantly decreased mRNA expression of the T_reg-specific marker FOXP3 in the blood of a large cohort of SCZ patients (n = 484) compared to CTRL (n = 472). Since CCL20 is a specific chemoattractant for CD4⁺CD25⁺CCR6⁺ T_regs, which are crucially involved in anti-inflammatory responses during brain (auto)inflammation, our results imply a plausible role for an altered astroglia-CCL20-CCR6-T_reg axis in SCZ pathophysiology.

A comparison study of metabolic profiles, immunity, and brain gray matter volumes between patients with bipolar disorder and depressive disorder

Background

Previous individual studies have shown the differences in inflammatory cytokines and gray matter volumes between bipolar disorder (BD) and unipolar depression (UD). However, few studies have investigated the association between pro-inflammatory cytokines and differences in brain gray matter volumes between BD and UD.

Methods

In this study, 72 BD patients and 64 UD patients were enrolled, with comparable gender and age distributions (33.8% males and an average age of 39.3 ± 13.7 years). Each participant underwent metabolic profiling (including body mass index (BMI), glucose, triglyceride, high-density lipoprotein (HDL), leptin, insulin, adiponectin), pro-inflammatory cytokine (including soluble interleukin-6 receptor (sIL-6R), soluble interleukin-2 receptor (sIL-2R), C-reactive protein (CRP), soluble tumor necrosis factor receptor type 1 (sTNF-R1) examinations, and structural magnetic resonance imaging exams. Voxel-based morphometry was performed to investigate the gray matter volume differences between BD and UD patients. Correlations between pro-inflammatory cytokines and the gray matter volume difference were analyzed.

Results

Compared to UD patients, the BD group had significantly higher BMI, and higher levels of sIL-6R and sTNF-R1 than the UD patients. The BMI significantly correlated with the level of pro-inflammatory cytokines. Adjusted for age, sex, BMI, duration of illness and total intracranial volume, the BD individuals had significantly more reduced gray matter volumes over 12 areas: R. cerebellar lobule VIII, R. putamen, L. putamen, R. superior frontal gyrus, L. lingual gyrus, L. precentral gyrus, R. fusiform gyrus, L. calcarine, R. precuneus, L. inferior temporal gyrus, L. hippocampus, and L. superior frontal gyrus. These 12 gray matter volume differences between BP and UD patients negatively correlated with sIL-6R and sTNF-R1 levels.

Conclusions

Our results suggested that BD patients had higher BMI and pro-inflammatory cytokine levels in comparison to UD patients, especially IL-6 and sTNF-R1, which may contribute to greater gray matter reductions in BD patients in comparison to UD patients. The results support the neuro-inflammation pathophysiology mechanism in mood disorder. It is clinically important to monitor BMI, which, in this investigation, positively correlated with levels of inflammatory cytokines.

The Neuroimmune and Neurotoxic Fingerprint of Major Neurocognitive Psychosis or Deficit Schizophrenia: a Supervised Machine Learning Study

No studies have examined the immune fingerprint of major neurocognitive psychosis (MNP) or deficit schizophrenia using M1 macrophage cytokines in combination with chemokines such as CCL2 and CCL11. The present study delineated the neuroimmune fingerprint of MNP by analyzing plasma levels of IL-1β, sIL-1RA, TNFα, sTNFR1, sTNFR2, CCL2, and CCL11 in 120 MNP versus 54 healthy controls in association with neurocognitive scores (as assessed with the Brief Assessment of Cognition in Schizophrenia) and PHEMN (psychotic, hostility, excitation, mannerism and negative) symptoms. MNP was best predicted by a combination of CCL11, TNFα, IL-1β, and sIL-1RA which yielded a bootstrapped (n = 2000) area under the receiver operating curve of 0.985. Composite scores reflecting M1 macrophage activity and neurotoxic potential including effects of CCL11 and CCL2 were significantly increased in MNP. A large part of the variance in PHEM (38.4-52.6%) and negative (65.8-74.4%) symptoms were explained by combinations of immune markers whereby CCL11 was the most important. The same markers explained a large part of the variance in the Mini-Mental State examination, list learning, digit sequencing task, category instances, controlled word association, symbol coding, and Tower of London. Partial least squares analysis showed that 72.7% of the variance in overall severity of schizophrenia was explained by the regression on IL-1β, sIL-1RA, CCL11, TNFα, and education. It is concluded that the combination of the abovementioned markers defines MNP as a distinct neuroimmune disorder and that increased immune neurotoxicity determines memory and executive impairments and PHEMN symptoms as well.

Predicting real-world functioning in outpatients with schizophrenia: Role of inflammation and psychopathology

Several studies indicate that negative and cognitive symptoms are determining factors of functioning in patients with schizophrenia. However, they do not usually include biological aspects, such as inflammatory markers. The current prospective study aims to identify clinical and biological factors predicting real-world functioning, at baseline and at one-year follow-up, of outpatients in an early stage of schizophrenia. Sample consist of 73 clinically stable patients with schizophrenia, of which 57 completed the one-year follow-up. Accurate psychopathology, functioning, and cognitive assessments were performed at baseline and follow-up (Positive and Negative Syndrome, Brief Negative Symptom, Calgary Depression, Personal and Social Performance Scales, and MATRICS Cognitive Consensus Battery). Biological biomarkers including anthropometric data and blood parameters were collected. Pearson correlation and multiple regression analyses including potential confounding factors were performed. Negative symptoms (especially asociality and avolition), along with the inflammatory biomarker interleukin-2, are the most important determining factors of poor real-world functioning in early-stage schizophrenia. The previous functioning, along with baseline cognitive performance in attention and vigilance, predicts functioning at one-year follow-up in these patients. Strategies aimed at improving negative and cognitive symptoms, as well as modifying certain inflammatory pathways, should be the targets to achieve functional recovery in the first years of schizophrenia.

The Role of Aberrations in the Immune-Inflammatory Response System (IRS) and the Compensatory Immune-Regulatory Reflex System (CIRS) in Different Phenotypes of Schizophrenia: the IRS-CIRS Theory of Schizophrenia

Several lines of evidence indicate that aberrations in immune-inflammatory pathways may contribute to the pathophysiology of schizophrenia spectrum disorders. Here, we propose a novel theoretical framework that was previously developed for major depression and bipolar disorder, namely, the compensatory immune-regulatory reflex system (CIRS), as applied to the neuro-immune pathophysiology of schizophrenia and its phenotypes, including first-episode psychosis (FEP), acute relapses, chronic and treatment-resistant schizophrenia (TRS), comorbid depression, and deficit schizophrenia. These schizophrenia phenotypes and manifestations are accompanied by increased production of positive acute-phase proteins, including haptoglobin and α2-macroglobulin, complement factors, and macrophagic M1 (IL-1β, IL-6, and TNF-α), T helper (Th)-1 (interferon-γ and IL-2R), Th-2 (IL-4, IL-5), Th-17 (IL-17), and T regulatory (Treg; IL-10 and transforming growth factor (TGF)-β1) cytokines, cytokine-induced activation of the tryptophan catabolite (TRYCAT) pathway, and chemokines, including CCL-11 (eotaxin), CCL-2, CCL-3, and CXCL-8. While the immune profiles in the different schizophrenia phenotypes indicate the activation of the immune-inflammatory response system (IRS), there are simultaneous signs of CIRS activation, including increased levels of the IL-1 receptor antagonist (sIL-1RA), sIL-2R and tumor necrosis factor-α receptors, Th-2 and Treg phenotypes with increased IL-4 and IL-10 production, and increased levels of TRYCATs and haptoglobin, α2-macroglobulin, and other acute-phase reactants, which have immune-regulatory and anti-inflammatory effects. Signs of activated IRS and CIRS pathways are also detected in TRS, chronic, and deficit schizophrenia, indicating that these conditions are accompanied by a new homeostatic setpoint between upregulated IRS and CIRS components. In FEP, increased baseline CIRS activity is a protective factor that may predict favorable clinical outcomes. Moreover, impairments in the CIRS are associated with deficit schizophrenia and greater impairments in semantic and episodic memory. It is concluded that CIRS plays a key role in the pathophysiology of schizophrenia by negatively regulating the primary IRS and contributing to recovery from the acute phase of illness. Therefore, components of the CIRS may offer promising therapeutic targets for schizophrenia.

On-treatment improvement of an emerging psychosomatic depressive disorder among salmonella carriers: a multicenter experience from Egypt

Background

As physicians in a referral hospital, we observed the association between history of enteric fever and somatic disorders associated with low mood. At the Al-Hussein University Hospital, Cairo and the National Liver Institute Hospital, Menoufia, we receive patients from all over Egypt, including rural areas where enteric fever is endemic.

Aim

Here in, 60 Egyptian patients referred to us for evaluation of different somatic disorders are reported.

Methods

After extensive evaluations, the patients' symptoms were function-related. Also, their typhoid carrier states were documented, and the severity of depression using Hamilton-D (HAM-D) questionnaire was evaluated and recorded. All patients were treated with ceftriaxone, 2 gm, IV, daily for 15 days. The clinical evaluation and Hamilton score were reassessed at the end of the treatment and 6 weeks thereafter. The patients did not receive any anti-depressant nor anti-anxiety treatment during their course. Typhoid carrier was defined by documenting the history of typhoid fever that was diagnosed by culturing the Salmonella species, and not by serology, isolated from stool culture along with febrile condition, plus the absence of fever in the past 3 weeks. The Widal test was not accepted as a criterion for enrollment.

Results

Patients showed clinically significant improvement in the somatic complaints, and their HAM-D score immediately post-treatment that was consolidated for 6 weeks post-treatment completion.

Conclusion

In this study, the typhoid carrier was associated with the psychosomatic depression that improved by antibiotic therapy.

Correlation between white blood cell count and mood-stabilising treatment response in two bipolar disorder trials

BACKGROUND

Immune system markers may predict affective disorder treatment response, but whether an overall immune system marker predicts bipolar disorder treatment effect is unclear.

METHODS

Bipolar CHOICE (N = 482) and LiTMUS (N = 283) were similar comparative effectiveness trials treating patients with bipolar disorder for 24 weeks with four different treatment arms (standard-dose lithium, quetiapine, moderate-dose lithium plus optimised personalised treatment (OPT) and OPT without lithium). We performed secondary mixed effects linear regression analyses adjusted for age, gender, smoking and body mass index to investigate relationships between pre-treatment white blood cell (WBC) levels and clinical global impression scale (CGI) response.

RESULTS

Compared to participants with WBC counts of 4.5-10 × 109/l, participants with WBC &lt; 4.5 or WBC ≥ 10 showed similar improvement within each specific treatment arm and in gender-stratified analyses.

CONCLUSIONS

An overall immune system marker did not predict differential treatment response to four different treatment approaches for bipolar disorder all lasting 24 weeks.

A five-year follow-up study of antioxidants, oxidative stress and polyunsaturated fatty acids in schizophrenia

OBJECTIVE

Oxidative stress and dysregulated antioxidant defence may be involved in the pathophysiology of schizophrenia. In the present study, we investigated changes in antioxidants and oxidative stress from an acute to a later stable phase. We hypothesised that the levels of oxidative markers are increased in schizophrenia compared with healthy controls; change from the acute to the stable phase; and are associated with the levels of membrane polyunsaturated fatty acids (PUFAs) and symptom severity.

METHODS

Fifty-five patients with schizophrenia spectrum disorders, assessed during an acute phase and 5 years later during a stable phase, and 51 healthy controls were included. We measured antioxidants (α-tocopherol, uric acid, albumin and bilirubin), markers of oxidative stress (F2-isoprostane and reactive oxygen metabolites) and membrane fatty acids. Antioxidants and oxidative stress markers were compared in schizophrenia versus healthy controls, adjusting for differences in sex, age and smoking, and changes over time. Associations between symptoms and PUFA were also investigated.

RESULTS

In the acute phase, α-tocopherol was significantly higher (p &lt; 0.001), while albumin was lower (p &lt; 0.001) compared with the stable phase. Changes in α-tocopherol were associated with PUFA levels in the acute phase. In the stable phase, schizophrenia patients had higher uric acid (p = 0.009) and lower bilirubin (p = 0.046) than healthy controls. CRP was higher in patients in the stable phase (p &lt; 0.001), and there was no significant change from the acute phase.

CONCLUSION

The present findings of change in antioxidant levels in the acute versus stable phase of schizophrenia the present findings suggest that redox regulation is dynamic and changes during different phases of the disorder.

Inflammatory markers are altered in severe mental disorders independent of comorbid cardiometabolic disease risk factors

BACKGROUND

Inflammation and immune activation have been implicated in the pathogenesis of severe mental disorders and cardiovascular disease (CVD). Despite high level of comorbidity, many studies of the immune system in severe mental disorders have not systematically taken cardiometabolic risk factors into account.

METHODS

We investigated if inflammatory markers were increased in schizophrenia (SCZ) and affective (AFF) disorders independently of comorbid CVD risk factors. Cardiometabolic risk factors (blood lipids, body mass index and glucose) and CVD-related inflammatory markers CXCL16, soluble interleukin-2 receptor (sIL-2R), soluble CD14 (sCD14), macrophage inhibitory factor and activated leukocyte cell adhesion molecule (ALCAM) were measured in n = 992 patients (SCZ, AFF), and n = 647 healthy controls. We analyzed the inflammatory markers before and after controlling for comorbid cardiometabolic risk factors, and tested for association with psychotropic medication and symptom levels.

RESULTS

CXCL16 (p = 0.03) and sIL-2R (p = 7.8 × 10-5) were higher, while sCD14 (p = 0.05) were lower in patients compared to controls after controlling for confounders, with significant differences in SCZ for CXCL16 (p = 0.04) and sIL-2R (p = 1.1 × 10-5). After adjustment for cardiometabolic risk factors higher levels of sIL-2R (p = 0.001) and lower sCD14 (p = 0.002) remained, also in SCZ (sIL-2R, p = 3.0 × 10-4 and sCD14, p = 0.01). The adjustment revealed lower ALCAM levels (p = 0.03) in patients. We found no significant associations with psychotropic medication or symptom levels.

CONCLUSION

The results indicate that inflammation, in particular enhanced T cell activation and impaired monocyte activation, are associated with severe mental disorders independent of comorbid cardiometabolic risk factors. This suggests a role of novel pathophysiological mechanisms in severe mental disorders, particularly SCZ.

A Systematic Review of the Effect of Probiotic Supplementation on Schizophrenia Symptoms

BACKGROUND

Derangements of the gut microbiome have been linked to increased systemic inflammation and central nervous system disorders, including schizophrenia. This systematic review thus aimed to investigate the hypothesis that probiotic supplementation improves schizophrenia symptoms.

METHODS

By using the keywords (probiotic OR gut OR microbiota OR microbiome OR yogurt OR yoghurt OR lactobacillus OR bifidobacterium) AND (schizophrenia OR psychosis), a preliminary search of the PubMed, Medline, Embase, Google Scholar, ClinicalTrials.gov, Clinical Trials Register of the Cochrane Collaboration Depression, Anxiety and Neurosis Group (CCDANTR), and Cochrane Field for Complementary Medicine databases yielded 329 papers published in English between January 1, 1960 and May 1, 2018. Attempts were made to search grey literature as well.

RESULTS

Three clinical studies were reviewed, comparing the use of probiotics to placebo controls. Applying per-protocol analysis and a fixed-effects model, there was no significant difference in schizophrenia symptoms between the group that received probiotic supplementation and the placebo group post-intervention as the standardized mean difference was -0.0884 (95% CI -0.380 to 0.204, p = 0.551). Separate analyses were performed to investigate the effect of probiotic supplementation on positive or negative symptoms of schizophrenia alone. In both instances, no significant difference was observed as well.

CONCLUSION

Based on current evidence, limited inferences can be made regarding the efficacy of probiotics in schizophrenia. Although probiotics may have other benefits, for example to regulate bowel movement and ameliorate the metabolic effects of antipsychotic medications, the clinical utility of probiotics in the treatment of schizophrenia patients remains to be validated by future clinical studies.

Risk factors of major infections in schizophrenia. A nationwide Danish register study

BACKGROUND

Risk of infections is elevated in patients with schizophrenia. Predicting their occurrence is essential, as infections in this group of patients are associated with prolonged hospital admission and increased mortality. The objective of the current investigation was to identify the potential risk factors of major infection after diagnosis with schizophrenia.

METHODS

This national prospective observational cohort study included 7788 people with schizophrenia born in Denmark between 1975 and 1990. Socio-demographic, psychiatric and health related data were obtained from Danish national registers. The Cox regression model was used for data analyses. Crude and adjusted hazard ratios (HRs) with 95% confidence intervals (95%CIs) are presented.

RESULTS

The most significant risk factors associated with the development of major infections included young age, female gender, medical comorbidity and substance abuse. A history of treatment with antipsychotics preceding the diagnosis was negatively associated with such morbidity.

CONCLUSION

This study reports several factors that might increase the risk of infections in individuals with schizophrenia. Early intervention towards infections should be considered in the subpopulation of schizophrenia patients who are at increased risk of infections.

Probiotics: A Potential Immunotherapeutic Approach for the Treatment of Schizophrenia

Probiotics are in use for physiological boosting, health supplement, and for treatment since historical time. Recently, the to-and-fro pathways linking the gut with the brain, explaining the indirect communication via modulation of immune function and levels of various neurotransmitters, have been discovered, but how precisely these modulations alter the levels of neurotransmitters contributing to the cognitive and other symptom improvements in patients with schizophrenia remains a new arena of research for psychiatry and psychology professionals. The germ-free mice experiments have been the game changer in the mechanistic exploration. The antimicrobial usage alters the local gut flora and hence is associated with psychiatric side effects that strengthen the association further. The changes in the genetics of these bacteria with different types of diet and its correlation with neurotransmitters production capacity and the psyche of the individual are indeed an emerging field for schizophrenia research. Redressal of issues such as manufacturing, the shelf life of probiotics, and stability of probiotics in the gut milieu, in the presence of food, secretions, and exact volume needed for particular age group will help in refining the dose duration of probiotic therapy. Clinical trials are underway for evaluating safety and efficacy in schizophrenia. The gut microorganism transplant and pharmacovigilance of probiotics are important areas yet to be addressed accurately. This paper elucidates the pathways, clinical studies, availability of probiotics in the Indian market with their composition, regulatory issues in India about the probiotic use, and future of probiotic research in schizophrenia.

Cytokine Alterations in Schizophrenia: An Updated Review

Schizophrenia, a multisystem disorder with an unknown etiology, is associated with several immune dysfunctions, including abnormal levels of circulating cytokines. In this review, we investigated the changes of cytokines in schizophrenic patients, their connection with behavioral symptoms severity and their potential clinical implications. We also assessed the possible causative role of abnormal cytokine levels in schizophrenia pathogenesis. Based on meta-analyses, we categorized cytokines according to their changes in schizophrenic patients into four groups: (1) increased cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β, IL-12, and transforming growth factor (TGF)-β, (2) non-altered cytokines, including IL-2, IL-4, and IL-17, (3) increased or non-altered cytokines, including IL-8 and interferon (IFN)-γ, and (4) IL-10 with increased, decreased, and non-altered levels. Notably, alterations in cytokines may be variable in four different categories of SP, including first-episode and drug-naïve, first-episode and non-drug-naïve, stable chronic, and chronic in acute relapse. Furthermore, disease duration, symptoms severity, incidence of aggression, and cognitive abilities are correlated with levels of certain cytokines. Clinical implications of investigating the levels of cytokine in schizophrenic patients include early diagnosis, novel therapeutic targets development, patient stratification for choosing the best therapeutic protocol, and predicting the prognosis and treatment response. The levels of IL-6, IL-8, IFN-γ, IL-2 are related to the treatment response. The available evidence shows a potential causative role for cytokines in schizophrenia development. There is a substantial need for studies investigating the levels of cytokines before disease development and delineating the therapeutic implications of the disrupted cytokine levels in schizophrenia.

Over-expression of TGF-β1 gene in medication free Schizophrenia

BACKGROUND AND PURPOSE

Immunological pathways play a crucial role in developing and precipitating neuropsychiatric disorders. Although the exact pathogenesis of schizophrenia is unknown, the possible role of genetic and biomarker involvement of the immune system is gaining attention. Here we quantified the mRNA expression of cytokines as a key role player of the immune system from the peripheral blood mononuclear cells of patients with schizophrenia and healthy controls to identify the differentially expressed genes.

METHODS

Sixteen medication-free schizophrenia patients and 16 healthy subjects were enrolled in the current study. To investigate the desired expression level of mRNAs including TGF-β1, IL-1β, IL-23, TNF-α, NF-κB, and BDNF, quantitative real-time PCR was performed using specific oligonucleotide primers and the Applied Bio systems StepOne™ real time PCR system. DNA methylation was also analyzed through methylation-specific polymerase chain reaction (MSP).

RESULTS

TGF-β1 was significantly up-regulated in peripheral blood mononuclear cells of patients vs. healthy individuals (P value = 0.03). In addition, we found a significant correlation between the positive symptom scale and TGF-β1 gene overexpression (r = 0.536, P = 0.039). However, we did not observe any statistically significant differences for the methylation status of CpG Islands 1 and 2 between the patients and normal group. No statistical significance was found either for gene expression of IL-1β (P = 0.32), IL-23 (P = 0.12), TNF-α (P = 0.87), NF-κB (P = 0.07), and BDNF (P = 0.33).

CONCLUSIONS

Although the number of medication-free schizophrenia patients is extremely limited, our data highlighted the potential role of TGF-β1 as a regulatory cytokine in complex inflammatory mechanism involved in medication-free schizophrenia. In addition, we observed that increased level of TGF-β1 mRNA in this disease might not be under methylation as an epigenetic control element at the genomic level.

Association between serum lipid levels, osteoprotegerin and depressive symptomatology in psychotic disorders

Although the relationship between positive and negative symptoms of psychosis and dyslipidemia has been thoroughly investigated in recent studies, the potential link between depression and lipid status is still under-investigated. We here examined the association between lipid levels and depressive symptomatology in patients with psychotic disorders, in addition to their possible inflammatory associations. Participants (n = 652) with the following distribution: schizophrenia, schizophreniform and schizoaffective disorder (schizophrenia group, n = 344); bipolar I, II, NOS, and psychosis NOS (non-schizophrenia group, n = 308) were recruited consecutively from the Norwegian Thematically Organized Psychosis (TOP) Study. Clinical data were obtained by Positive and Negative Syndrome Scale (PANSS), and Calgary Depression Scale for Schizophrenia (CDSS). Blood samples were analyzed for total cholesterol (TC), low-density lipoprotein (LDL), triglyceride (TG), C-reactive protein (CRP), soluble tumor necrosis factor receptor 1(sTNF-R1), osteoprotegerin (OPG), and interleukin 1 receptor antagonist (IL-1Ra). After adjusting for age, gender, BMI, smoking, and dyslipidemia-inducing antipsychotics, TC and LDL scores showed significant associations with depression [β = 0.13, p = 0.007; β = 0.14, p = 0.007], and with two inflammatory markers: CRP [β = 0.14, p = 0.007; β = 0.16, p = 0.007] and OPG [β = 0.14, p = 0.007; β = 0.11, p = 0.007]. Total model variance was 17% for both analyses [F(12, 433) = 8.42, p < 0.001; F(12, 433) = 8.64, p < 0.001]. Current findings highlight a potential independent role of depression and inflammatory markers, CRP and OPG in specific, in the pathophysiology of dyslipidemia in psychotic disorders.

Increased circulating regulatory T cells in medicated people with schizophrenia

Immunological abnormalities are increasingly reported in people with schizophrenia, but no clear functional biomarkers associated with genetic correlates of the disease have been found. Regulatory T cells (Tregs) are key immunoregulatory cells involved in the control of inflammatory processes and their functions are directly related to the human leucocyte antigen (HLA) gene, which has been implicated in schizophrenia genetic studies. However, there is a lack of studies reporting Treg status in people with schizophrenia. In the current study, the proportion of circulating Tregs was examined using flow cytometry in 26 medicated participants with schizophrenia and 17 healthy controls. Psychiatric symptoms and cognitive function were evaluated using the Scale for the Assessment of Negative Symptoms, the Brief Psychiatric Rating Scale, and the MATRICS Consensus Cognitive Battery. The proportion of Tregs was found to be significantly greater in the schizophrenia group compared to healthy controls. No differences were observed in total lymphocyte counts or CD3+ and CD4+ T cells, confirming a specific effect for Tregs. Elevated Tregs in schizophrenia correlated with fewer negative symptoms, a core domain of the illness. These results suggest that Tregs may contribute to improved negative symptoms in schizophrenia, possibly by counteracting on-going inflammatory processes.

Clinically relevant and simple immune system measure is related to symptom burden in bipolar disorder

OBJECTIVE

Immunological theories, particularly the sickness syndrome theory, may explain psychopathology in mood disorders. However, no clinical trials have investigated the association between overall immune system markers with a wide range of specific symptoms including potential gender differences.

METHODS

We included two similar clinical trials, the lithium treatment moderate-dose use study and clinical and health outcomes initiatives in comparative effectiveness for bipolar disorder study, enrolling 765 participants with bipolar disorder. At study entry, white blood cell (WBC) count was measured and psychopathology assessed with the Montgomery and Aasberg depression rating scale (MADRS). We performed analysis of variance and linear regression analyses to investigate the relationship between the deviation from the median WBC, and multinomial regression analysis between different WBC levels. All analyses were performed gender-specific and adjusted for age, body mass index, smoking, race, and somatic diseases.

RESULTS

The overall MADRS score increased significantly for each 1.0×109/l deviation from the median WBC among 322 men (coefficient=1.10; 95% CI=0.32-1.89; p=0.006), but not among 443 women (coefficient=0.56; 95% CI=-0.19-1.31; p=0.14). Among men, WBC deviations were associated with increased severity of sadness, inner tension, reduced sleep, reduced appetite, concentration difficulties, inability to feel, and suicidal thoughts. Among women, WBC deviations were associated with increased severity of reduced appetite, concentration difficulties, lassitude, inability to feel, and pessimistic thoughts. Both higher and lower WBC levels were associated with increased severity of several specific symptoms.

CONCLUSION

Immune system alterations were associated with increased severity of specific mood symptoms, particularly among men. Our results support the sickness syndrome theory, but furthermore emphasise the relevance to study immune suppression in bipolar disorder. Due to the explorative nature and cross-sectional design, future studies need to confirm these findings.

Anti-inflammatory treatment of depression: study protocol for a randomised controlled trial of vortioxetine augmented with celecoxib or placebo

Background

In patients with major depressive disorder (MDD), antidepressant response and remission rates are low, highlighting the need for new treatment approaches. Recently, the abundant literature linking inflammatory processes and depressive symptoms have led to the hypothesis that selecting treatment for MDD based on the patient’s inflammatory status could be a promising strategy to improve outcomes in patients suffering from MDD. The aim of the randomised control trial we propose is to investigate the antidepressant efficacy of the combined treatment of MDD with antidepressant medication plus anti-inflammatory medication in individuals with raised inflammation levels. For the first time, this study will prospectively test the efficacy of an antidepressant plus anti-inflammatory augmentation based on baseline inflammatory maker levels in MDD using a randomised controlled trial design.

Methods

This study proposes to measure blood C-reactive protein (CRP) levels before the initiation of treatment in 200 participants with MDD. Study participants are then assigned into one of two study strata: either into the ‘Depression with inflammation’ stratum (CRP levels > 3 mg/L); or into the ‘Depression without inflammation’ stratum (CRP levels ≤ 3 mg/L). Within each of the two study strata, participants randomly receive either antidepressant medication alone (vortioxetine) plus anti-inflammatory medication (celecoxib) or vortioxetine plus placebo for six weeks. At the end of the treatment period, participants have the opportunity to continue vortioxetine alone for a six-month post-trial period. Clinical outcomes are measured at baseline, fortnightly during the treatment period and at the three-month and six-month post-trial visits. The primary outcome is change in MADRS score, with a primary endpoint of a score reduction by 50% from baseline to six weeks (end of augmentation treatment with celecoxib). Secondary clinical outcomes are changes in the cognitive dimensions of depression (cognitive function, emotion processing and social cognition). Biological outcome measures (levels of CRP and other inflammatory markers) are measured at baseline, after six weeks of treatment and at the six-month post-trial visit.

Discussion

The current study will generate novel evidence for biomarker-based personalised antidepressant treatment selection based on patient inflammatory status before treatment.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12617000527369p. Registered on 11 April 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2829-7) contains supplementary material, which is available to authorized users.

Prenatal exposure to environmental insults and enhanced risk of developing Schizophrenia and Autism Spectrum Disorder: focus on biological pathways and epigenetic mechanisms

When considering neurodevelopmental disorders (NDDs), Schizophrenia (SZ) and Autism Spectrum Disorder (ASD) are considered to be among the most severe in term of prevalence, morbidity and impact on the society. Similar features and overlapping symptoms have been observed at multiple levels, suggesting common pathophysiological bases. Indeed, recent genome-wide association studies (GWAS) and epidemiological data report shared vulnerability genes and environmental triggers across the two disorders. In this review, we will discuss the possible biological mechanisms, including glutamatergic and GABAergic neurotransmissions, inflammatory signals and oxidative stress related systems, which are targeted by adverse environmental exposures and that have been associated with the development of SZ and ASD. We will also discuss the emerging role of the gut microbiome as possible interplay between environment, immune system and brain development. Finally, we will describe the involvement of epigenetic mechanisms in the maintenance of long-lasting effects of adverse environments early in life. This will allow us to better understand the pathophysiology of these NDDs, and also to identify novel targets for future treatment strategies.

C4A mRNA expression in PBMCs predicts the presence and severity of delusions in schizophrenia and bipolar disorder with psychosis

Altered immune function is an established finding in psychotic disorders such as schizophrenia and bipolar disorder with psychosis, though its role in their development and progression remains to be understood. Evidence suggests altered JAK-STAT1 pathway activity in peripheral blood cells from participants with schizophrenia compared to controls. Activation of this pathway leads to increased expression of complement component 4A (C4A), which has recently been implicated in schizophrenia. Here, we examine mRNA expression of C4A in peripheral blood cells from participants with schizophrenia, bipolar disorder and controls. STAT1 and IRF-1 mRNA expression are included as measures of JAK-STAT1 pathway activation in the same participants. Further, we examine the association of each genes mRNA expression with clinical symptom measures using the Positive and Negative Syndrome Scale (PANSS) and the Psychotic Symptom Rating Scale (PSYRATS). We demonstrate that C4A, STAT1 and IRF-1 mRNA expression levels are correlated across the entire sample, indicating shared transcriptional regulatory mechanisms. Further, we show that C4A mRNA expression alone is positively associated with psychotic symptomatology, specifically the presence and severity of delusions. These findings are noteworthy given recent findings that demonstrate a critical role for complement proteins in synaptic pruning, alterations of which are proposed to contribute to psychopathology in psychosis.

Cytokines dysregulation in schizophrenia: A systematic review of psychoneuroimmune relationship

INTRODUCTION

Schizophrenia is a multifactorial psychiatric disease with complex interactions among the brain and the immune system. A psycho-immune relationship underling schizophrenia is supported by several studies and integrates a specific area of knowledge - psychoneuroimmunology.

METHODS

A systematic review was performed by 2009 Preferred Reporting Items (PRISMA) recommendations. Based on the inclusion/exclusion criteria, publications with relevant information (evaluated by the Joanna Briggs Institute Critical Appraisals tools to quality assessment) were included.

RESULTS

In this review, we considered the inflammatory activity promoted by cytokine alterations in schizophrenia aetiology, which reflects the systemic comprehension of this disease in opposition to the traditional approach focused solely on the brain. We focus on the analysis of several specific outcomes, such as proinflammatory cytokines, sample sort, laboratory techniques, diagnosis scales and results of each publication.

CONCLUSION

This systematic review confirms the existence of cytokines abnormalities in schizophrenia disease. Immune imbalances such as increased levels of some cytokines (either at protein level or at mRNA expression), cytokine mRNAs, as well as cytokine gene polymorphisms have been reported with a large support in schizophrenia. These findings provide a strong evidence of a concomitant process of inflammatory activity in schizophrenia illness course.

Can interleukin-2 and interleukin-1β be specific biomarkers of negative symptoms in schizophrenia?

INTRODUCTION

Evidence suggests the existence of cytokine disturbances in patients with schizophrenia but their association with psychopathology is still unclear. The aim of the current study was to determine if pro-inflammatory cytokine levels (tumor necrosis factor-α, interleukin (IL)-6, IL-2, IL-1β, IL-1RA) are increased in stable outpatients compared with healthy subjects, and to analyze if they could be specific biomarkers of clinical dimensions in schizophrenia.

METHODS

We studied 73 stable outpatients with schizophrenia in their first 10 years of illness and 73 age- and sex-matched healthy controls. An accurate assessment of clinical dimensions (positive, negative, depressive, cognitive) was performed in patients.

RESULTS

Only IL-6 levels were significantly increased in patients after controlling for body mass index, waist circumference, smoking, and psychopharmacological treatment, compared with healthy subjects. After adjusting for several confounders, multiple linear regression models identified that Positive and Negative Syndrome Scale negative symptoms, general psychopathology, and global severity are predicted by IL-1β concentrations, while motivation and pleasure domain of Clinical Assessment Interview for Negative Symptoms and Personal and Social Performance global functioning scores are predicted by IL-2 levels. Cognitive performance, positive, and depressive symptom severity did not correlate with any cytokine.

CONCLUSIONS

Our findings suggested that IL-6 concentrations are elevated in stable patients with schizophrenia. Whereas IL-2 specifically marks severity of the motivation and pleasure domain of negative symptoms, IL-1β is not specific to this dimension as it also predicts severity of general and global symptomatology.

Oxidative stress biomarkers and clinical dimensions in first 10 years of schizophrenia

INTRODUCTION

Several studies have described increased oxidative stress parameters in patients with schizophrenia. The objectives of the current study were to identify potential oxidative stress biomarkers in stable patients during first 10 years of schizophrenia and determine if they are associated with specific clinical dimensions.

MATERIAL AND METHODS

Seventy-three clinically stable outpatients with schizophrenia and 73 sex and age-matched healthy controls were recruited. Sociodemographic, clinical and biological data were collected at enrollment. Blood biomarkers included homocysteine, the percentage of hemolysis, lipid peroxidation subproducts, and as an antioxidant biomarker, catalase activity in erythrocytes.

RESULTS

Comparative analyses after controlling for smoking and metabolic syndrome evidenced a significant increase in catalase activity in patients. Also, lower lipid peroxidation levels showed an association with negative symptoms.

CONCLUSIONS

In conclusion, compensatory antioxidant mechanisms might be increased in stable patients with schizophrenia at early stages. Furthermore, there may be an inverse relationship between oxidative stress and negative dimension.