Acute phase proteins in schizophrenia, mania and major depression: modulation by psychotropic drugs

Blood Plasma Markers in Depressed Mice under Chronic Social Defeat Stress

It has previously been shown that, in mice, chronic social defeat stress in daily agonistic interactions leads to a depression-like state similar to that in depressive patients. With this model, it has become obvious that it is possible to study peripheral markers of the depression-like state in an experiment. This paper was aimed at searching for protein markers in the blood plasma of depressed mice in the chronic social conflict model, which allows for us to obtain male mice with repeated experiences of defeat. Proteomic analysis of blood plasma samples was conducted to identify proteins differentially expressed in this state. There were changes in the expression levels of the amyloid proteins SAA1, SAA4, and SAMP and apolipoproteins APOC3, APOD, and ADIPO in the blood plasma of depressed mice compared with controls (unstressed mice). Changes in the expression of serine protease inhibitors and/or proteins associated with lipid metabolism, inflammation, or immune function [ITIH4, SPA3, A1AT5, HTP (HP), CO9, and A2MG] were also found. Here, we showed that chronic social stress is accompanied by increased levels of amyloid proteins and apolipoproteins in blood plasma. A similarity was noted between the marker protein expression changes in the depressed mice and those in patients with Alzheimer's disease. These data indicate a psychopathogenic role of chronic social stress, which can form a predisposition to neurodegenerative and/or psychoemotional disorders.

The influence of chronic inflammation on the illnesscourse of bipolar disorder: A longitudinal study

INTRODUCTION

C-reactive protein (CRP) is a systemic inflammatory marker, which indicates systemic inflammatory processes It is involved in different inflammatory processes of the body and is a reliable marker for the general inflammatory state of the body. High sensitive CRP seems to play a key role as a state and trait marker of bipolar disorder (BD). In the current study, we tried to determine the long-term effect of CRP levels on clinical symptoms and illness course of bipolar disorder.

METHODS

For the current study, we examined 106 patients with BD for a period of four years. Participants underwent a clinical screening for depressive and manic episodes with the Hamilton Depression Scale (HAMD) and the Young Mania Rating Score (YMRS) and a serological diagnostic for inflammatory parameters every six months, thus leading to 8 measurement times in total. Patients with the presence of severe medical or neurological comorbidities such as active cancer, chronic obstructive lung disease, rheumatoid arthritis, systemic lupus erythematosus, Alzheimer's disease, Parkinson's disease, Huntington's disease or multiple sclerosis and acute infections were not included in the study.

RESULTS

In our sample, 26% showed a mean hsCRP above 5 mg/dl. Those patients showed a significantly higher mean YMRS score than those with a mean hsCRP under 5 mg/dl during our observation period. Regarding HAMD there was no significant difference in hsCRP values. The existence of lithium treatment showed no significant influence on mean hsCRP levels between the start and endpoint.

CONCLUSION

Individuals who were exposed to a higher level of inflammation over time suffered from more manic symptoms in this period. These findings underline the hypothesis that inflammatory processes have an accumulative influence on the illness course of BD, especially concerning manic symptoms and episodes.

Integrated proteomic and genomic analysis to identify predictive biomarkers for valproate response in bipolar disorder: a 6-month follow-up study

BACKGROUND

Several genetic studies have been undertaken to elucidate the intricate interplay between genetics and drug responses in bipolar disorder (BD). However, there has been notably limited research on biomarkers specifically linked to valproate, with only a few studies investigating integrated proteomic and genomic factors in response to valproate treatment. Therefore, this study aimed to identify biological markers for the therapeutic response to valproate treatment in BD. Patients with BD in remission were assessed only at baseline, whereas those experiencing acute mood episodes were evaluated at three points (baseline, 8 ± 2 weeks, and 6 ± 1 months). The response to valproate treatment was measured using the Alda scale, with individuals scoring an Alda A score ≥ 5 categorized into the acute-valproate responder (acute-VPAR) group. We analyzed 158 peptides (92 proteins) from peripheral blood samples using multiple reaction monitoring mass spectrometry, and proteomic result-guided candidate gene association analyses, with 1,627 single nucleotide variants (SNVs), were performed using the Korean chip.

RESULTS

The markers of 37 peptides (27 protein) showed temporal upregulation, indicating possible association with response to valproate treatment. A total of 58 SNVs in 22 genes and 37 SNVs in 16 genes showed nominally significant associations with the Alda A continuous score and the acute-VPAR group, respectively. No SNVs reached the genome-wide significance threshold; however, three SNVs (rs115788299, rs11563197, and rs117669164) in the secreted phosphoprotein 2 gene reached a gene-based false discovery rate-corrected significance threshold with response to valproate treatment. Significant markers were associated with the pathophysiological processes of bipolar disorders, including the immune response, acute phase reaction, and coagulation cascade. These results suggest that valproate effectively suppresses mechanisms associated with disease progression.

CONCLUSIONS

The markers identified in this study could be valuable indicators of the underlying mechanisms associated with response to valproate treatment.

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.

Differential expression of haptoglobin in individuals at clinical high risk of psychosis and its association with global functioning and clinical symptoms

BACKGROUND

Immune dysregulation has been observed in patients with schizophrenia or first-episode psychosis, but few have examined dysregulation in those at clinical high-risk (CHR) for psychosis. The aim of this study was to examine whether the peripheral blood-based proteome was dysregulated in those with CHR. Secondly, we examined whether baseline dysregulation was related to current and future functioning and clinical symptoms.

METHODS

We used data from participants of the North American Prodromal Longitudinal Studies (NAPLS) 2 and 3 (n = 715) who provided blood samples (Unaffected Comparison subjects (UC) n = 223 and CHR n = 483). Baseline proteomic data was quantified from plasma samples using mass spectrometry. Differential expression was examined between CHR and UC using logistic regression. Psychosocial functioning was measured using the Global Assessment of Functioning scale (GAF). Symptoms were measured using the subscale scores from the Scale of Psychosis-risk Symptoms; positive, negative, general, and disorganised. Three measures of each outcome were included: baseline, longest available follow-up (last follow-up) and most severe follow-up (MSF). Associations between the proteomic data, GAF and symptoms were assessed using ordinal regression.

RESULTS

Of the 99 proteins quantified, six were differentially expressed between UC and CHR. However, only haptoglobin (HP) survived FDR-correction (OR:1.45, 95 %CI:1.23-1.69, padj = <0.001). HP was cross-sectionally and longitudinally associated with functioning and symptoms such that higher HP values were associated with poorer functioning and more severe symptoms. Results were evident after stringent adjustment and poorer functioning was observed in both NAPLS cohort separately.

CONCLUSION

We demonstrate that elevated HP is robustly observed in those at CHR for psychosis, irrespective of transition to psychosis. HP is longitudinally associated with poorer functioning and greater symptom severity. These results agree with previous reports of increased HP gene expression in individuals at-risk for psychosis and with the dysfunction of the acute phase inflammatory response seen in psychotic disorders.

Transcriptome profiling of bovine endometrial epithelial cells induced by lipopolysaccharides in vitro

Endometritis is an inflammation of the surface of the endometrium that does not penetrate the submucosa and can cause infertility and increase the elimination rate in cows. Endometrial epithelial cells are the first barrier of the endometrium against foreign stimuli and bacterial infection. Understanding the genetic changes in stimulated endometrial epithelial cells will help in the efforts to prevent and treat endometritis. This study investigated changes in bovine endometrial epithelial (BEEC) gene expression induced by lipopolysaccharide (LPS)-induced inflammation and compared transcriptome-wide gene changes between LPS- and phosphate-buffered saline (PBS)- treated BEECs by RNA sequencing. Compared with the PBS group, the LPS group showed 60 differentially expressed genes (DEGs) (36 upregulated, 24 downregulated). Gene Ontology enrichment analysis revealed that most enrichment occurred during CXCR chemokine receptor binding, inflammatory response, and neutrophil migration. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed DEGs mainly concentrated in cytokine-cytokine receptor interactions; IL-17, tumor necrosis factor, NOD-like receptor, chemokine, Toll-like receptor, and nuclear factor-κB signaling pathways; and the cytoplasmic DNA sensing pathway. Moreover, results revealed that cytokines SAA3 and HP increased significantly after LPS treatment. These effects of LPS on BEECs transcriptome and the molecular mechanism of endometritis provide a basis for improved clinical treatment and novel drug development.

Association between albumin and depression: a population-based study

INTRODUCTION

Albumin is the most prevalent plasma protein and is involved in a variety of critical physiological processes. Low serum albumin levels have been linked to depression symptoms in people who had recent suicide attempts and those suffering from several mental diseases such as acute episodes of mania, and schizophrenia. However, there has been little investigation into the relationship between depression and serum albumin levels in community-dwelling persons. This research aimed to examine the relationship between serum albumin and depression in a population-based sample and whether it differs depending on other possible confounders.

METHODS

Our data were derived from a national household population study conducted in 2017 with a sample size of 3,521 Jordanians aged > 17 years old. The Patient Health Questionnaire (PHQ-9) scale, a self-administered scale, was used to screen for depression. Concentrations of serum albumin and other medical biomarkers were measured by blood tests. Using descriptive statistics for depression distribution and multivariate logistic regression analysis, the connection between albumin levels and depression was investigated.

RESULTS

The odds ratios (ORs) for depression were significantly lower in the third and fourth quartiles of serum albumin concentration compared to the first quartile (OR = 0.64 and 0.66, respectively; P values = <0.001 and <0.001, respectively). This association was statistically significant even after controlling for variables such as gender, age, marital status, education, and occupation (OR = 0.67 and 0.75, respectively, and P values = 0.001 and 0.02, respectively), as well as after further controlling for other health status variables such as nutrition, comorbidity, body mass index, somking status, and biomedical markers such as serum calcium, phosphate, and magnesium (OR = 0.58 and 0.59, respectively, and P values = <0.001 and 0.001, respectively). Moreover, the unadjusted and adjusted odds ratios in the three regression models declined linearly with rising quartiles of serum albumin (P trend = <0.001, 0.009, and 0.001, respectively).

CONCLUSIONS

Our research found an inverse relationship between serum albumin and depression. Serum albumin could be a warning measure for depression. It is required for appropriate intervention measures to be implemented.

Complement proteins are elevated in blood serum but not CSF in clinical high-risk and antipsychotic-naïve first-episode psychosis

Alterations in the complement system have been reported in some people with psychotic disorder, including in pre-psychotic individuals, suggesting that complement pathway dysregulation may be a feature of the early psychosis phenotype. Measurement of complement protein expression in psychosis has been largely restricted to the blood from patients with established illness who were taking antipsychotic medication. The present study examined a range of complement proteins in blood and cerebrospinal fluid (CSF) derived from individuals at clinical high-risk for psychosis (CHR), antipsychotic-naïve first-episode psychosis (FEP) and healthy controls. A panel of complement proteins (C1q, C3, C3b/iC3b, C4, factor B and factor H) were quantified in serum and matched CSF in 72 participants [n = 23 individuals at CHR, n = 24 antipsychotic-naïve FEP, n = 25 healthy controls] using a multiplex immunoassay. Analysis of covariance was used to assess between-group differences in complement protein levels in serum and CSF. Pearson's correlation was used to assess the relationship between serum and CSF proteins, and between complement proteins and symptom severity. In serum, all proteins, except for C3, were significantly higher in FEP and CHR. While a trend was observed, protein levels in CSF did not statistically differ between groups and appeared to be impacted by BMI and sample storage time. Across the whole sample, serum and CSF protein levels were not correlated. In FEP, higher levels of serum classical and alternative grouped pathway components were correlated with symptom severity. Our exploratory study provides evidence for increased activity of the peripheral complement system in the psychosis spectrum, with such elevations varying with clinical severity. Further study of complement in CSF is warranted. Longitudinal investigations are required to elucidate whether complement proteins change peripherally and/or centrally with progression of psychotic illness.

Association of the plasma complement system with brain volume deficits in bipolar and major depressive disorders

BACKGROUND

Inflammation plays a crucial role in the pathogenesis of major depressive disorder (MDD) and bipolar disorder (BD). This study aimed to examine whether the dysregulation of complement components contributes to brain structural defects in patients with mood disorders.

METHODS

A total of 52 BD patients, 35 MDD patients, and 53 controls were recruited. The human complement immunology assay was used to measure the levels of complement factors. Whole brain-based analysis was performed to investigate differences in gray matter volume (GMV) and cortical thickness (CT) among the BD, MDD, and control groups, and relationships were explored between neuroanatomical differences and levels of complement components.

RESULTS

GMV in the medial orbital frontal cortex (mOFC) and middle cingulum was lower in both patient groups than in controls, while the CT of the left precentral gyrus and left superior frontal gyrus were affected differently in the two disorders. Concentrations of C1q, C4, factor B, factor H, and properdin were higher in both patient groups than in controls, while concentrations of C3, C4 and factor H were significantly higher in BD than in MDD. Concentrations of C1q, factor H, and properdin showed a significant negative correlation with GMV in the mOFC at the voxel-wise level.

CONCLUSIONS

BD and MDD are associated with shared and different alterations in levels of complement factors and structural impairment in the brain. Structural defects in mOFC may be associated with elevated levels of certain complement factors, providing insight into the shared neuro-inflammatory pathogenesis of mood disorders.

In Schizophrenia, Chronic Fatigue Syndrome- and Fibromyalgia-Like Symptoms are Driven by Breakdown of the Paracellular Pathway with Increased Zonulin and Immune Activation-Associated Neurotoxicity

BACKGROUND

A meaningful part of schizophrenia patients suffer from physiosomatic symptoms (formerly named psychosomatic), which are reminiscent of chronic fatigue syndrome and fibromyalgia (FF) and are associated with signs of immune activation and increased levels of tryptophan catabolites (TRYCATs).

AIMS

The study aims to examine whether FF symptoms in schizophrenia are associated with the breakdown of the paracellular pathway, zonulin, lowered natural IgM responses to oxidative specific epitopes (OSEs); and whether FF symptoms belong to the behavioral-cognitive-physical-psychosocial- (BCPS)-worsening index consisting of indices of a general cognitive decline (G-CoDe), symptomatome of schizophrenia, and quality of life (QoL)-phenomenome.

METHODS

FF symptoms were assessed using the Fibromyalgia and Chronic Fatigue Rating scale in 80 schizophrenia patients and 40 healthy controls and serum cytokines/chemokines, IgA levels to TRYCATs, IgM to OSEs, zonulin and transcellular/paracellular (TRANS/PARA) molecules were assayed using ELISA methods.

RESULTS

A large part (42.3%) of the variance in the total FF score was explained by the regression on the PARA/TRANS ratio, pro-inflammatory cytokines, IgM to zonulin, IgA to TRYCATs (all positively), and IgM to OSEs (inversely). There were highly significant correlations between the total FF score and G-CoDe, symtopmatome, QoL phenomenome, and BCPS-worsening score. FF symptoms belong to a common core shared by G-CoDe, symtopmatome, and QoL phenomenome.

CONCLUSION

The physio-somatic symptoms of schizophrenia are driven by various pathways, including increased zonulin, breakdown of the paracellular tight-junctions pathway, immune activation with induction of the TRYCAT pathway, and consequent neurotoxicity. It is concluded that FF symptoms are part of the phenome of schizophrenia and BCPS-worsening as well.

Adjunctive minocycline for major depressive disorder: A sub-study exploring peripheral immune-inflammatory markers and associated treatment response

Background

Adjunctive minocycline shows promise in treating affective and psychotic disorders; however, the therapeutic mechanism remains unclear. Identifying relevant biomarkers may enhance the efficacy of novel adjunctive treatment candidates. We thus investigated the peripheral immune-inflammatory profile in a randomized controlled trial (RCT) of minocycline in major depressive disorder (MDD).

Methods

This sub-study investigated serum samples from a RCT evaluating minocycline (200 mg/day, 12 weeks) in addition to treatment as usual for MDD (ACTRN12612000283875). Of the original sample (N = 71), serum assays were conducted in 47 participants (placebo n = 24; minocycline n = 23) targeting an array of 46 immune-inflammatory analytes including cytokines, chemokines, and acute-phase reactants. General estimating equations (GEE) were used to assess whether analyte concentration at baseline (effect modification) and change in analytes (change association) influenced change in Montgomery-Åsberg Depression Rating Scale (MADRS) score over time. The Benjamini-Hochberg approach was applied when adjusting for false discovery rates (FDR).

Results

GEE models revealed several interaction effects. After adjusting for FDR several change association-models survived correction. However, no such models remained significant for effect modification. Three-way group × time × marker interactions were significant for complement C3 (B = -10.46, 95%CI [-16.832, -4.095], q = 0.019) and IL-1Ra (B = -9.008, 95%CI [-15.26, -2.751], q = 0.036). Two-way group × biomarker interactions were significant for ICAM-1/CD54 (B = -0.387, 95%CI [-0.513, -0.26], q < 0.001) and IL-8/CXCL8 (B = -4.586, 95%CI [-7.698, -1.475], q = 0.036) indicating that increases in the serum concentration of these analytes were associated with an improvement in MADRS scores in the minocycline group (compared with placebo).

Conclusions

Change in complement C3, IL-1Ra, IL-8/CXCL8, and ICAM-1 may be associated with greater change in depressive scores following adjunctive minocycline treatment in MDD. Further investigations are needed to assess the utility of these biomarkers.

Neuronal oscillations: early biomarkers of psychiatric disease?

Our understanding of the environmental and genetic factors contributing to the wide spectrum of neuropsychiatric disorders has significantly increased in recent years. Impairment of neuronal network activity during early development has been suggested as a contributor to the emergence of neuropsychiatric pathologies later in life. Still, the neurobiological substrates underlying these disorders remain yet to be fully understood and the lack of biomarkers for early diagnosis has impeded research into curative treatment options. Here, we briefly review current knowledge on potential biomarkers for emerging neuropsychiatric disease. Moreover, we summarize recent findings on aberrant activity patterns in the context of psychiatric disease, with a particular focus on their potential as early biomarkers of neuropathologies, an essential step towards pre-symptomatic diagnosis and, thus, early intervention.

Dysregulation of complement system in neuropsychiatric disorders: A mini review

Complement system is one of the most important defense mechanisms of the innate immune system. In addition to their roles in immune regulation, complement proteins are also involved in neurodevelopment and adult brain plasticity. Complement dysregulation has been shown in neurodevelopmental disorders including schizophrenia and autism spectrum disorder as well as in mood disorders. A number of clinical as well as genetic studies suggest the role of complement proteins in the cortical thinning and excessive synaptic pruning frequently associated with schizophrenia. The changes in complement proteins are also associated with the pathophysiology of autism spectrum disorder, major depressive disorder and bipolar disorder, but warrant further research. In addition, rodent models suggest a strong case for complement system in anxiety-like behavior. In this article, we review the recent findings on the role of complement system in neuropsychiatric disorders. The possible uses for future complement targeted therapies are also discussed.

Plasma complement C3 and C3a are increased in major depressive disorder independent of childhood trauma

BACKGROUND

Dysregulated complement system is linked to pathophysiology of major depressive disorder (MDD). Childhood trauma has been associated with an increased incidence of adult depression via a putative mechanism of immune activation. This study aimed to measure and compare peripheral levels of complement C3, C3a, C1q and C-reactive protein (CRP) in MDD patients and healthy controls and explore the relationship between these molecule levels and childhood trauma history in the participants.

METHODS

The participants were 49 medication-free MDD patients and 45 healthy controls. All participants were asked to finish the Childhood Trauma Questionnaire, followed by blood sampling for measurement of plasma complement C3, C3a, C1q and CRP by means of enzyme-linked immunosorbent assay.

RESULTS

Peripheral plasma concentration of C3 and C3a in medication-free MDD group was significantly higher than that in the healthy controls; whereas the concentration of plasma C1q and CRP in depressed patients was comparable to that in healthy controls. All these inflammatory factors were not associated to childhood trauma experience in patients with MDD.

CONCLUSION

Our data suggest that complement C3 and C3a may be implicated in the pathophysiology of MDD, although traumatic childhood experiences were not associated with the circulating levels of complement C3, C3a, C1q and CRP.

The interleukin-6/interleukin-23/T helper 17-axis as a driver of neuro-immune toxicity in the major neurocognitive psychosis or deficit schizophrenia: A precision nomothetic psychiatry analysis

BACKGROUND

Schizophrenia and especially deficit schizophrenia (DSCZ) are characterized by increased activity of neuroimmunotoxic pathways and a generalized cognitive decline (G-CoDe). There is no data on whether the interleukin (IL)-6/IL-23/T helper 17 (IL-6/IL-23/Th17)-axis is more associated with DSCZ than with non-deficit schizophrenia (NDSCZ) and whether changes in this axis are associated with the G-CoDe and the phenome (a factor extracted from all symptom domains) of schizophrenia.

METHODS

This study included 45 DSCZ and 45 NDSCZ patients and 40 controls and delineated whether the IL-6/IL-23/Th17 axis, trace elements (copper, zinc) and ions (magnesium, calcium) are associated with DSCZ, the G-CoDe and the schizophrenia phenome.

RESULTS

Increased plasma IL-23 and IL-6 levels were associated with Th17 upregulation, assessed as a latent vector (LV) extracted from IL-17, IL-21, IL-22, and TNF-α. The IL-6/IL-23/Th17-axis score, as assessed by an LV extracted from IL-23, IL-6, and the Th17 LV, was significantly higher in DSCZ than in NDSCZ and controls. We discovered that 70.7% of the variance in the phenome was explained by the IL-6/IL-23/Th17-axis (positively) and the G-CoDe and IL-10 (both inversely); and that 54.6% of the variance in the G-CoDe was explained by the IL-6/IL-23/Th17 scores (inversely) and magnesium, copper, calcium, and zinc (all positively).

CONCLUSION

The pathogenic IL-6/IL-23/Th17-axis contributes to the generalized neurocognitive deficit and the phenome of schizophrenia, especially that of DSCZ, due to its key role in peripheral inflammation and neuroinflammation and its consequent immunotoxic effects on neuronal circuits. These clinical impairments are more prominent in subjects with lowered IL-10, magnesium, calcium, and zinc.

The Tryptophan Catabolite or Kynurenine Pathway in a Major Depressive Episode with Melancholia, Psychotic Features and Suicidal Behaviors: A Systematic Review and Meta-Analysis

Major depressive disorder (MDD) and bipolar disorder (BD) with melancholia and psychotic features and suicidal behaviors are accompanied by activated immune-inflammatory and oxidative pathways, which may stimulate indoleamine 2,3-dioxygenase (IDO), the first and rate-limiting enzyme of the tryptophan catabolite (TRYCAT) pathway resulting in increased tryptophan degradation and elevated tryptophan catabolites (TRYCTAs). The purpose of the current study is to systematically review and meta-analyze levels of TRP, its competing amino acids (CAAs) and TRYCATs in patients with severe affective disorders. Methods: PubMed, Google Scholar and SciFinder were searched in the present study and we recruited 35 studies to examine 4647 participants including 2332 unipolar (MDD) and bipolar (BD) depressed patients and 2315 healthy controls. Severe patients showed significant lower (p < 0.0001) TRP (standardized mean difference, SMD = -0.517, 95% confidence interval, CI: -0.735; -0.299) and TRP/CAAs (SMD = -0.617, CI: -0.957; -0.277) levels with moderate effect sizes, while no significant difference in CAAs were found. Kynurenine (KYN) levels were unaltered in severe MDD/BD phenotypes, while the KYN/TRP ratio showed a significant increase only in patients with psychotic features (SMD = 0.224, CI: 0.012; 0.436). Quinolinic acid (QA) was significantly increased (SMD = 0.358, CI: 0.015; 0.701) and kynurenic acid (KA) significantly decreased (SMD = -0.260, CI: -0.487; -0.034) in severe MDD/BD. Patients with affective disorders with melancholic and psychotic features and suicidal behaviors showed normal IDO enzyme activity but a lowered availability of plasma/serum TRP to the brain, which is probably due to other processes such as low albumin levels.

The plasma level of complement component 4A decreases with aripiprazole treatment in patients with early psychosis

The complement component 4 (C4) gene has been reported to be significantly associated with schizophrenia, and C4A RNA expression was found to increase in postmortem brains of schizophrenia patients. This study aimed to examine the plasma levels of C4A and C4B proteins in patients with early psychosis and their changes following aripiprazole treatment. We recruited 45 patients, including 17 patients with ultra-high-risk and 28 patients with first-episode psychosis, and 45 age-matched and sex-matched controls. All patients received aripiprazole treatment for 4 weeks. Each patient received symptom evaluation before and after the treatment period. We measured the plasma levels of C4A and C4B in the pretreatment and posttreatment stages of patients and controls using an enzyme-linked immunosorbent assay. We found no significant differences in C4A and C4B levels between patients and controls, but the C4A level decreased significantly with aripiprazole treatment. Multivariate analysis showed that the decrease rate of C4A was significantly associated with the treatment response of the positive symptom dimension. In summary, we found that the plasma level of C4A decreased with aripiprazole treatment, and the decrease rate was associated with the treatment response of the positive dimension in patients with early psychosis. This mechanism deserves further clarification.

Association Between the C4 Binding Protein Level and White Matter Integrity in Major Depressive Disorder

OBJECTIVE

Considerable evidence suggests that neuroinflammation plays an important role in the pathophysiology of major depressive disorder (MDD). However, the relationship between serum C4 binding protein (C4BP) and white matter (WM) tract integrity in MDD has not been investigated.

METHODS

We obtained diffusion tensor images of 44 patients with MDD and 44 healthy controls and performed TRActs Constrained by UnderLying Anatomy (TRACULA) analysis to assess WM tract integrity. Serum C4-binding protein alpha chain (C4BPA) and C4- binding protein beta chain (C4BPB) levels were measured and in-between group comparisons were obtained. The correlation between serum C4BP levels and WM tract integrity was examined.

RESULTS

In comparison to healthy controls, both serum C4BPA and C4BPB were higher in MDD. Also, fractional anisotropy (FA) was increased in the left cingulum-angular bundle (CAB) in MDD, but not healthy controls (HCs). A significant correlation was found between serum C4BP and FA levels in the right cingulum-cingulate gyrus bundle (CCG) in MDD.

CONCLUSION

This study is the first to investigate the correlation between serum C4BP levels and WM tract integrity in MDD. We identified an increase in WM integrity in the left CAB region in MDD. Furthermore, serum C4BP levels were higher in MDD, and this finding correlated with increased WM integrity in the right CCG region.

Plasma complement component 4 alterations in patients with schizophrenia before and after antipsychotic treatment

This study was performed to investigate the plasma C4 level and the influence of antipsychotic medication in schizophrenic patients. Thirty-six schizophrenic patients were followed-up for a mean of four weeks. The plasma level of C4 in schizophrenia was significantly higher than that in healthy controls at baseline, and was significantly decreased after antipsychotic treatment. CRP at both baseline and follow-up in patients were comparable to that in healthy controls. Our findings indicate that the plasma level of C4 is increased in schizophrenia patients at the acute stage of illness and can be decreased by antipsychotic medication.

Complement Dependent Synaptic Reorganisation During Critical Periods of Brain Development and Risk for Psychiatric Disorder

We now know that the immune system plays a major role in the complex processes underlying brain development throughout the lifespan, carrying out a number of important homeostatic functions under physiological conditions in the absence of pathological inflammation or infection. In particular, complement-mediated synaptic pruning during critical periods of early life may play a key role in shaping brain development and subsequent risk for psychopathology, including neurodevelopmental disorders such as schizophrenia and autism spectrum disorders. However, these disorders vary greatly in their onset, disease course, and prevalence amongst sexes suggesting complex interactions between the immune system, sex and the unique developmental trajectories of circuitries underlying different brain functions which are yet to be fully understood. Perturbations of homeostatic neuroimmune interactions during different critical periods in which regional circuits mature may have a plethora of long-term consequences for psychiatric phenotypes, but at present there is a gap in our understanding of how these mechanisms may impact on the structural and functional changes occurring in the brain at different developmental stages. In this article we will consider the latest developments in the field of complement mediated synaptic pruning where our understanding is beginning to move beyond the visual system where this process was first described, to brain areas and developmental periods of potential relevance to psychiatric disorders.

Schizophrenia risk loci from xMHC region were associated with antipsychotic response in chronic schizophrenic patients with persistent positive symptom

We examined whether common variants from the extended major histocompatibility complex (xMHC) region contribute to the response to antipsychotic drugs (APDs) in patients with schizophrenia with persistent psychosis. Subjects participated in a prospective longitudinal study of the effect of APDs on psychopathology were temporally split into discovery (n = 88) and replication (n = 42) cohorts. The primary endpoint was a change in Brief Psychiatric Rating Scale at 6-week or 6-month after treatment. rs204991 (β = 3.917, p = 3.72 × 10^-6), the strongest signal associated with response at 6-week was located near C4A/C4B after a linear regression adjusted for covariates. xMHC SNP imputation disclosed much stronger signals (rs9268469, β = 5.140, p = 1.57 × 10^-7) and other weaker signals (p < 1 × 10^-5) spanning the entire xMHC region. All the variants were previously identified schizophrenia risk loci. Conditional fine-mapping revealed three subgroups of SNPs which were the eQTLs (p < 1 × 10^-7) for C4A, HLA-C, and BTN3A2 in disease-relevant tissue. Epistasis between HLA-C and C4A was observed (p = 0.019). Minor allele (G) carriers of rs204991, eQTL for C4A, having decreased risk for schizophrenia and lower imputed expression of C4A, had a better response to APDs. Some imputed HLA alleles associated with a decreased risk for schizophrenia had a positive association with improvement in psychotic symptoms. An independent cohort validated the association of change in psychosis with C4A. We provide evidence that genetic risk factors for schizophrenia from the xMHC region are associated with response to APDs and those variants significantly alter the imputed expression of C4A, HLA-C, and BTN3A2. The minor alleles predicting higher C4A level are associated with diminished improvement in psychotic symptoms after APD treatment.

Gut dysbiosis in severe mental illness and chronic fatigue: a novel trans-diagnostic construct? A systematic review and meta-analysis

Reduced gut-microbial diversity ("gut dysbiosis") has been associated with an anhedonic/amotivational syndrome ("sickness behavior") that manifests across severe mental disorders and represent the key clinical feature of chronic fatigue. In this systematic review and meta-analysis, we investigated differences in proxy biomarkers of gut dysbiosis in patients with severe mental illness and chronic fatigue vs. controls and the association of these biomarkers with sickness behavior across diagnostic categories. Following PRISMA guidelines, we searched from inception to April 2020 for all the studies investigating proxy biomarkers of gut dysbiosis in patients with severe mental illness and chronic fatigue. Data were independently extracted by multiple observers, and a random-mixed model was used for the analysis. Heterogeneity was assessed with the I² index. Thirty-three studies were included in the systematic review; nineteen in the meta-analysis (N = 2758 patients and N = 1847 healthy controls). When compared to controls, patients showed increased levels of zonulin (four studies reporting data on bipolar disorder and depression, SMD = 0.97; 95% Cl = 0.10-1.85; P = 0.03, I² = 86.61%), lipopolysaccharide (two studies reporting data on chronic fatigue and depression, SMD = 0.77; 95% Cl = 0.42-1.12; P < 0.01; I² = 0%), antibodies against endotoxin (seven studies reporting data on bipolar disorder, depression, schizophrenia, and chronic fatigue, SMD = 0.99; 95% CI = 0.27-1.70; P < 0.01, I² = 97.14%), sCD14 (six studies reporting data on bipolar disorder, depression, schizophrenia, and chronic fatigue, SMD = 0.54; 95% Cl 0.16-0.81; P < 0.01, I² = 90.68%), LBP (LBP, two studies reporting data on chronic fatigue and depression, SMD = 0.87; 95% Cl = 0.25-1.48; P < 0.01; I² = 56.80%), alpha-1-antitripsin (six studies reporting data on bipolar disorder, depression, and schizophrenia, SMD = 1.23; 95% Cl = 0.57-1.88; P < 0.01, I²: 89.25%). Elevated levels of gut dysbiosis markers positively correlated with severity of sickness behavior in patients with severe mental illness and chronic fatigue. Our findings suggest that gut dysbiosis may underlie symptoms of sickness behavior across traditional diagnostic boundaries. Future investigations should validate these findings comparing the performances of the trans-diagnostic vs. categorical approach. This will facilitate treatment breakthrough in an area of unmet clinical need.

Isobaric Tags for Relative and Absolute Quantitation Identification of Blood Proteins Relevant to Paroxetine Response in Patients With Major Depressive Disorder

OBJECTIVES

Isobaric tags for relative and absolute quantitation (iTRAQ) is a proteomic investigation that could be utilized for rapid identification and quantification of proteins, which we would use to identify differentially expressed proteins in treatment responsive patients with major depressive disorder (MDD).

METHODS

Six treatment responsive patients of MDD were recruited, and their peripheral blood mononuclear cell (PBMC) were collected before and after 4 weeks of paroxetine treatment. iTRAQ and Mascot search engine were used to detect differentially expressed proteins, which were then validated by Western blot.

RESULTS

Two thousand one hundred and fifty three proteins were screened, and seven proteins showed differences of more than two-fold and 62 proteins with a differences of less than two-fold. Six proteins with commercially available antibodies were identified, and were validated by Western blot in 10 paroxetine responsive MDD patients. Putative hydroxypyruvate isomerase (HYI), eukaryotic translation initiation factor 4H (eIF4H), and RNA binding motif 8A (RBM8A) had statistically significant differences before and after treatment in the validation. Data are available via ProteomeXchange with identifier PXD028947.

CONCLUSIONS

By using iTRAQ and Western blot, we were able to identify HYI, eIF4H, and RAM8a to be the potential predictors of paroxetine treatment response in patients with MDD. This finding could help establish future individualized medicine.

Suicide attempts are associated with activated immune-inflammatory, nitro-oxidative, and neurotoxic pathways: A systematic review and meta-analysis

BACKGROUND

Suicide attempts (SA) frequently occur in patients with mood disorders and schizophrenia, which are both accompanied by activated immune-inflammatory and nitro-oxidative (IO&NS) pathways.

METHODS

We searched PubMed, Google Scholar, and Web of Science, for articles published from inception until February 1, 2021. We included studies that compared blood biomarkers in psychiatric patients with (SA+) and without SA (SA-) and heathy controls and we combined different IO&NS biomarkers into immune, inflammatory, and neurotoxic profiles and used meta-analysis (random-effect model with restricted maximum-likelihood) to delineate effect sizes with 95% confidence interval (CI).

FINDINGS

Our search included 51 studies comprising 4.945 SA+ patients and 24.148 controls. We stratified the control group into healthy controls and SA- patients. SA+ patients showed significantly (p<0.001) increased immune activation (SMD: 1.044; CI: 0.599, 1.489), inflammation (SMD: 1.109; CI: 0.505, 1.714), neurotoxicity (SMD: 0.879; CI: 0.465, 1.293), and lowered neuroprotection (SMD: 0.648; CI: 0.354, 0.941) as compared with healthy controls. When compared with SA- patients, those with SA+ showed significant (p<0.001) immune activation (SMD: 0.290; CI: 0.183, 0.397), inflammation (SMD: 0.311; CI: 0.191, 0.432), and neurotoxicity (SMD: 0.315; CI: 0.198, 0.432), and lowered neuroprotection (SMD: 0.341; CI: 0.167, 0.515). Patients with current, but not lifetime, SA showed significant (p<0.001) levels of inflammation and neurotoxicity as compared with controls.

CONCLUSIONS

Patients with immune activation are at a higher risk of SA which may be explained by increased neurotoxicity due to inflammation and nitro-oxidative stress. This meta-analysis discovered new biomarkers of SA and therapeutic targets to treat individuals with SA.

Neuropsychiatric disorders: An immunological perspective

Neuropsychiatric diseases have traditionally been studied from brain, and mind-centric perspectives. However, mounting epidemiological and clinical evidence shows a strong correlation of neuropsychiatric manifestations with immune system activation, suggesting a likely mechanistic interaction between the immune and nervous systems in mediating neuropsychiatric disease. Indeed, immune mediators such as cytokines, antibodies, and complement proteins have been shown to affect various cellular members of the central nervous system in multitudinous ways, such as by modulating neuronal firing rates, inducing cellular apoptosis, or triggering synaptic pruning. These observations have in turn led to the exciting development of clinical therapies aiming to harness this neuro-immune interaction for the treatment of neuropsychiatric disease and symptoms. Besides the clinic, important theoretical fundamentals can be drawn from the immune system and applied to our understanding of the brain and neuropsychiatric disease. These new frameworks could lead to novel insights in the field and further potentiate the development of future therapies to treat neuropsychiatric disease.

First Episode Psychosis and Schizophrenia Are Systemic Neuro-Immune Disorders Triggered by a Biotic Stimulus in Individuals with Reduced Immune Regulation and Neuroprotection

There is evidence that schizophrenia is characterized by activation of the immune-inflammatory response (IRS) and compensatory immune-regulatory systems (CIRS) and lowered neuroprotection. Studies performed on antipsychotic-naïve first episode psychosis (AN-FEP) and schizophrenia (FES) patients are important as they may disclose the pathogenesis of FES. However, the protein–protein interaction (PPI) network of FEP/FES is not established. The aim of the current study was to delineate a) the characteristics of the PPI network of AN-FEP and its transition to FES; and b) the biological functions, pathways, and molecular patterns, which are over-represented in FEP/FES. Toward this end, we used PPI network, enrichment, and annotation analyses. FEP and FEP/FES are strongly associated with a response to a bacterium, alterations in Toll-Like Receptor-4 and nuclear factor-κB signaling, and the Janus kinases/signal transducer and activator of the transcription proteins pathway. Specific molecular complexes of the peripheral immune response are associated with microglial activation, neuroinflammation, and gliogenesis. FEP/FES is accompanied by lowered protection against inflammation, in part attributable to dysfunctional miRNA maturation, deficits in neurotrophin and Wnt/catenin signaling, and adherens junction organization. Multiple interactions between reduced brain derived neurotrophic factor, E-cadherin, and β-catenin and disrupted schizophrenia-1 (DISC1) expression increase the vulnerability to the neurotoxic effects of immune molecules, including cytokines and complement factors. In summary: FEP and FES are systemic neuro-immune disorders that are probably triggered by a bacterial stimulus which induces neuro-immune toxicity cascades that are overexpressed in people with reduced anti-inflammatory and miRNA protections, cell–cell junction organization, and neurotrophin and Wnt/catenin signaling.

Levels of lymphocyte-associated regulators of complement system CD55 and CD59 are changed in schizophrenia patients

OBJECTIVE

Although pathological mechanisms of schizophrenia are unknown, evidence in the literature suggests that the immune system might be involved in the pathogenesis. Complement is an important part of the immune system and it has been suggested to play role in the pathogenesis of schizophrenia. We aimed to investigate the potential involvement of the complement system in schizophrenia by the determination of peripheral concentrations of certain complement proteins and their regulators in patients.

METHODS

Plasma concentrations of complement C3, C4, and C1 inhibitory protein were measured by chemiluminescence in 41 schizophrenia patients and 39 healthy controls. Expression of CD55, CD59, and CD46 proteins on peripheral blood mononuclear cells were determined by flow cytometry in the same groups.

RESULTS

Frequencies of peripheral immune cells expressing CD55 were determined to be significantly higher in schizophrenia patients than in healthy people (p = 0.020). Frequencies of peripheral immune cells expressing CD59 was determined to be significantly higher in healthy people than in schizophrenia patients (p = 0.012). The expression level of CD55 per cell was measured to be significantly elevated in patients compared to healthy controls (p = 0.026).

CONCLUSIONS

Our data clearly demonstrate an elevated complement activity in schizophrenia and points to a possible complement association in the pathogenesis.Key pointsIncreased the expression level, and frequency of CD55 in schizophrenia patients.Decreased frequency of CD59 in schizophrenia patients.No difference in the expression level of CD59; the expression level, and frequency of CD46; frequency of complement C3, C4, and C1 inhibitory protein.

Transthyretin as a Biomarker to Predict and Monitor Major Depressive Disorder Identified by Whole-Genome Transcriptomic Analysis in Mouse Models

Background: Accumulations of stressful life events result in the onset of major depressive disorder (MDD). Comprehensive genomic analysis is required to elucidate pathophysiological changes and identify applicable biomarkers. Methods: Transcriptomic analysis was performed on different brain parts of a chronic mild stress (CMS)-induced MDD mouse model followed by systemic analysis. QPCR and ELISA were utilized for validation in mice and patients. Results: The highest numbers of genes with significant changes induced by CMS were 505 in the amygdala followed by 272 in the hippocampus (twofold changes; FDR, p < 0.05). Enrichment analysis indicated that the core-enriched genes in CMS-treated mice were positively enriched for IFN-γ response genes in the amygdala, and hedgehog signaling in the hippocampus. Transthyretin (TTR) was severely reduced in CMS-treated mice. In patients with diagnosed MDD, serum concentrations of TTR were reduced by 48.7% compared to controls (p = 0.0102). Paired samples from patients with MDD demonstrated a further 66.3% increase in TTR at remission compared to the acute phase (p = 0.0339). Conclusions: This study provides comprehensive information on molecular networks related to MDD as a basis for further investigation and identifies TTR for MDD monitoring and management. A clinical trial with bigger patient cohort should be conducted to validate this translational study.

Deficit schizophrenia and its features are associated with PON1 Q192R genotypes and lowered paraoxonase 1 (PON1) enzymatic activity: effects on bacterial translocation

BACKGROUND

Primary deficit schizophrenia (DS) is characterized by enduring negative symptoms and represents a qualitatively different disease entity with respect to non-deficit schizophrenia (NDS). No studies investigated the association between the enzyme paraoxonase 1 (PON1) and DS and its phenomenology.

METHODS

In this case-control study, Thai women and men, aged 18 to 65 years, were divided in DS (n = 40) and NDS (n = 40) and were compared to controls (n = 40). PON1 activities against 4-(chloromethyl)phenyl acetate (CMPA) and phenylacetate were determined. Moreover, subjects were genotyped for their PON1 Q192R polymorphism and immunoglobulin A (IgA) levels responses directed to Gram-negative bacteria were measured.

RESULTS

DS is significantly associated with the QQ genotype and the Q allele as compared with NDS and controls. PON1 activities are significantly and inversely associated with negative symptoms, formal thought disorders, psychomotor retardation, excitation and DS. The presence of the Q allele is associated with increased IgA responses to Pseudomonas aeruginosa, Morganella morganii, and Pseudomonas putida as compared with RR carriers.

CONCLUSIONS

The PON1 Q allele and lower PON1 activities especially against CMPA are associated with DS, indicating lowered quorum quenching abilities as well as lowered defenses against lipoperoxidation and immune activation. It is suggested that lowered PON1 activity in DS constitutes an impairment in the innate immune system which together with lowered natural IgM may cause lower immune regulation thereby predisposing toward greater neurotoxic effects of immune-inflammatory, oxidative and nitrosative pathways and Gram-negative microbiota.

Involvement of Hemopexin in the Pathogenesis of Proteinuria in Children with Idiopathic Nephrotic Syndrome

Hemopexin (Hpx) is considered a factor in the pathogenesis of idiopathic nephrotic syndrome (INS). The aim of the study was to evaluate the serum and urine values of Hpx (sHpx and uHpx) in children with INS, analyze the role of Hpx, and assess its usefulness as a marker of the disease course. 51 children with INS and 18 age-matched controls were examined. Patients were divided into subgroups depending on the number of relapses (group IA-the first episode of INS, group IB-with relapses) and according to method of treatment (group IIA treated with gluco-corticosteroids (GCS), group IIB treated with GCS and other immunosuppressants). Hpx concentrations were determined by enzyme-linked immunosorbent assay (ELISA). sHpx and uHpx values in relapse were elevated in the whole INS group versus controls (p < 0.000). In remission their levels decreased, but still remained higher than in the control group (p < 0.000). In group IB uHpx levels were increased during remission as compared to group IA (p < 0.006). No significant impact of immuno-suppressants on sHpx was observed, but uHpx excretion in group IIA was higher in relapse (p < 0.026) and lower in remission (p < 0.0017) as compared to group IIB. The results suggest the role of Hpx in the pathogenesis of INS. Hpx may be a useful indicator for continuation of treatment, but it requires confirmation by further controlled studies.

Associations Between Genotype and Peripheral Complement Proteins in First-Episode Psychosis: Evidences From C3 and C4

Schizophrenia is a common neuropsychiatric disorder with complex pathophysiology. Recent reports suggested that complement system alterations contributed to pathological synapse elimination that was associated with psychiatric symptoms in schizophrenia. Complement component 3 (C3) and complement component 4 (C4) play central roles in complement cascades. In this study, we compared peripheral C3 and C4 protein levels between first-episode psychosis (FEP) and healthy control (HC). Then we explored whether single nucleotide polymorphisms (SNPs) at C3 or C4 genes affect peripheral C3 or C4 protein levels. In total, 181 FEPs and 204 HCs were recruited after providing written informed consent. We measured serum C3 and C4 protein levels using turbidimetric inhibition immunoassay and genotyped C3 and C4 polymorphisms using the Sequenom MassArray genotyping. Our results showed that three SNPs were nominally associated with schizophrenia (rs11569562/C3: A > G, p = 0.048; rs2277983/C3: A > G, p = 0.040; rs149898426/C4: G > A, p = 0.012); one haplotype was nominally associated with schizophrenia, constructed by rs11569562–rs2277983–rs1389623 (GGG, p = 0.048); FEP had higher serum C3 and C4 (both p < 0.001) levels than HC; rs1389623 polymorphisms were associated with elevated C3 levels in our meta-analysis (standard mean difference, 0.50; 95% confidence interval, 0.30 to 0.71); the FEP with CG genotype of rs149898426 had higher C4 levels than that with GG genotypes (p = 0.005). Overall, these findings indicated that complement system altered in FEP and rs149898426 of C4 gene represented a genetic risk marker for schizophrenia likely through mediating complement system. Further studies with larger sample sizes needs to be validated.

Plasma Indoleamine-2,3-Dioxygenase (IDO) is Increased in Drug-Naï ve Major Depressed Patients and Treatment with Sertraline and Ketoprofen Normalizes IDO in Association with Pro-Inflammatory and Immune- Regulatory Cytokines

BACKGROUND

Major Depression Disorder (MDD) is accompanied by an immune response characterized by increased levels of inflammatory and immune-regulatory cytokines and stimulation of indoleamine-2,3-dioxygenase (IDO). There is also evidence that anti-inflammatory drugs may have clinical efficacy in MDD.

METHODS

This study examined a) IDO in association with interferon (IFN)-γ, Interleukin (IL)-4 and Transforming Growth Factor (TGF)-β1 in 140 drug-naïve MDD patients and 40 normal controls; and b) the effects of an eight-week treatment of sertraline with or without ketoprofen (a nonsteroidal antiinflammatory drug) on the same biomarkers in 44 MDD patients.

RESULTS

Baseline IDO, IFN-γ, TGF-β1 and IL-4 were significantly higher in MDD patients as compared with controls. Treatment with sertraline with or without ketoprofen significantly reduced the baseline levels of all biomarkers to levels which were in the normal range (IDO, TGF-β1, and IL-4) or still somewhat higher than in controls (IFN-γ). Ketoprofen add-on had a significantly greater effect on IDO as compared with placebo. The reductions in IDO, IL-4, and TGF-β1 during treatment were significantly associated with those in the BDI-II.

CONCLUSION

MDD is accompanied by activated immune-inflammatory pathways (including IDO) and the Compensatory Immune-Regulatory System (CIRS). The clinical efficacy of antidepressant treatment may be ascribed at least in part to decrements in IDO and the immune-inflammatory response. These treatments also significantly reduce the more beneficial properties of T helper-2 and T regulatory (Treg) subsets. Future research should develop immune treatments that target the immune-inflammatory response in MDD while enhancing the CIRS.

Inflammatory and Oxidative Pathways Are New Drug Targets in Multiple Episode Schizophrenia and Leaky Gut, Klebsiella pneumoniae, and C1q Immune Complexes Are Additional Drug Targets in First Episode Schizophrenia

Breakdown of paracellular and vascular pathways and activated neuroimmune and oxidative pathways was established in (deficit) schizophrenia. The aim of this study was to delineate (a) the differences in these pathways between stable-phase, first (FES) and multiple (MES) episode schizophrenia and (b) the pathways that determine the behavioral-cognitive-physical-psychosocial (BCPS) deterioration in FES/MES. This study included 21 FES and 58 FES patients and 40 healthy controls and measured indicants of serum C1q circulating immune complexes (CIC), leaky gut, immune activation, and oxidative stress toxicity (OSTOX). We constructed a BCPS-worsening index by extracting a latent vector from symptomatic, neurocognitive, and quality of life data. FES was associated with higher IgA CIC-C1q, IgA directed to cadherin, catenin, and plasmalemma vesicle-associated protein, and IgA/IgM to Gram-negative bacteria as compared with FES and controls. In FES patients, the BCPS-worsening score was predicted (48.7%) by IgA to Klebsiella pneumoniae and lowered paraoxonase 1 activity. In MES patients, the BCPS-worsening score was explained (42.7%) by increased tumor necrosis factor-α, OSTOX, and number of episodes. In schizophrenia, 34.0% of the variance in the BCPS-worsening score was explained by IgA to K. pneumoniae, OSTOX, and number of episodes. Increased IgA to K. pneumoniae was the single best predictor of residual psychotic symptoms in FES and MES. This study delineated different mechanistic processes in FES, including breakdown of adherens junctions, bacterial translocation, and IgA CIC-C1q formation, and MES, including immune and oxidative neurotoxic pathways. FES and MES comprise different staging subtypes, i.e., FES and MES with and without worsening.

[Variations in immunological parameters after treatment of a manic episode]

Bipolar disorder is a chronic and disabling mental illness affecting approximately 1-2% of the general population, characterized by the occurrence of manic episodes alone or alternating with depressive episodes. Bipolar disorder is associated with significant morbidity, mortality and personal suffering. The mechanisms underlying the onset and progression of bipolar disease are still poorly understood. Recently, immunological dysfunctions have been suggested in the pathogenesis of bipolar disorder, and many studies have focused on the interaction between bipolar disorder and immunity. Immunological changes have been widely studied during depressive episodes but less explored during manic episodes. The objective of our study was to explore changes in serum proteins and autoantibodies after treatment for a manic episode of bipolar I disorder. This study was carried out over a 30-month period from January 2017 to June 2019, in collaboration between the psychiatry department B of the Hédi Chaker CHU and the immunology department of the Habib Bourguiba CHU, in Sfax, Tunisia. It focused on a sample of 45 bipolar patients with manic relapse, naïve to psychotropic treatment, or discontinuing treatment for a period of at least three months and without a history of autoimmune disease. The study was conducted in two stages : on admission and after treatment. The mean plasma levels of IgG and complement C3 fraction were significantly higher in bipolar patients with relapsing mania. Studies of variation in immunoglobulins and complement fractions during relapses of bipolar disorder have all objected to variations in these serum proteins, but their results were inconsistent regarding the direction of variation and the fractions affected. After treatment, there was a statistically significant increase in the mean plasma levels of IgG and IgA and a decrease in the mean plasma level of the C4 fraction of complement. No significant variation in autoantibodies was noted after treatment. The mean plasma IgM level was significantly lower with sodium valproate. On atypical antipsychotic medication, the mean plasma level of fraction C3 was statistically lower, whereas on conventional antipsychotic medication it was statistically higher. This is in line with the data in the literature which support the immunomodulatory role of thymoregulators and antipsychotics. Serum proteins have been more sensitive than autoantibodies to the effect of psychotropic therapy during manic relapse.

Proteome Analysis of PC12 Cells Reveals Alterations in Translation Regulation and Actin Signaling Induced by Clozapine

Although antipsychotics are routinely used in the treatment of schizophrenia for the last decades, their precise mechanism of action is still unclear. In this study, we investigated changes in the PC12 cells’ proteome under the influence of clozapine, risperidone, and haloperidol to identify protein pathways regulated by antipsychotics. Analysis of the protein profiles in two time points: after 12 and 24 h of incubation with drugs revealed significant alterations in 510 proteins. Further canonical pathway analysis revealed an inhibition of ciliary trophic factor signaling after treatment with haloperidol and showed a decrease in acute phase response signaling in the risperidone group. Interestingly, all tested drugs have caused changes in PC12 proteome which correspond to inhibition of cytokines: tumor necrosis factor (TNF) and transforming growth factor beta 1 (TGF-β1). We also found that the 12-h incubation with clozapine caused up-regulation of protein kinase A signaling and translation machinery. After 24 h of treatment with clozapine, the inhibition of the actin cytoskeleton signaling and Rho proteins signaling was revealed. The obtained results suggest that the mammalian target of rapamycin complex 1 (mTORC1) and 2 (mTORC2) play a central role in the signal transduction of clozapine.

Complement component C4 levels in the cerebrospinal fluid and plasma of patients with schizophrenia

Abnormalities in the complement system have been described in patients with schizophrenia, with those individuals having greater frequency of complement component 4A (C4A) alleles and higher C4A transcript levels in postmortem brain tissue. Importantly, abnormalities in C4A and other complement molecules have been associated with synaptic pruning abnormalities that occur during neurodevelopment. A few studies have investigated C4 levels in living patients with schizophrenia, but all of them did so using peripheral blood samples. No studies have examined C4 levels in cerebrospinal fluid (CSF), presumably a better biofluid choice given its intimate contact with the brain. Therefore, we report for the first time on C4 levels in CSF and plasma of patients with schizophrenia. In this study, we obtained CSF in 32 patients with schizophrenia spectrum disorders and 32 healthy volunteers and peripheral blood samples in 33 SSD and 31 healthy volunteers. C4 levels were measured using Abcam ELISA assays. Univariate analysis did not show a statistically significant difference in CSF C4 values between groups. However, a multivariable analysis showed a statistically significant increase in CSF C4 levels between groups after adjusting for sex and age. We also observed a high correlation between CSF C4 levels and age. By contrast, plasma C4 levels were not significantly different between groups. CSF and plasma C4 levels were not significantly correlated. Therefore, the use of CSF samples is critical and should be complementary to the use of peripheral blood samples to allow for a comprehensive understanding of complement C4 abnormalities in schizophrenia.

Peripheral immune markers and antipsychotic non-response in psychosis

BACKGROUND

Peripheral immune markers have previously been linked to a poor response to antipsychotic medication and more severe negative symptoms at the onset of psychosis. The present study investigated the association of blood cytokines and complement markers with the presence of antipsychotic non-response and symptom severity in patients with psychosis.

METHODS

This cross-sectional study recruited 94 patients with schizophrenia and other psychoses, of whom 47 were defined as antipsychotic responders and 47 as antipsychotic non-responders. In all subjects we measured plasma levels of cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α, and IFN-γ), complement markers (C1-inhibitor, C3, C4, C3a, C3b, Bb, factor D, C5a, terminal complement complex) and high sensitivity C-reactive protein (hsCRP). Symptom severity was recorded using the Positive and Negative Syndrome scale for Schizophrenia (PANSS). Binary logistic regression tested each immune marker as predictor of response status while covarying for relevant socio-demographic variables. Correlation analyses tested the association between immune markers and the severity of symptoms.

RESULTS

Interleukin (IL)-8 significantly predicted antipsychotic non-response (OR=24.70, 95% CI, 1.35-453.23, p = 0.03). Other immune markers were not associated with antipsychotic response. IL-6, IL-8, IL-10 and TNF-α significantly positively correlated with negative psychotic symptoms.

CONCLUSIONS

Higher levels of IL-8 are associated with a poor response to antipsychotic treatment. Increased cytokines levels are specifically associated with more severe negative symptoms in patients with schizophrenia and other psychoses.

Association between complement component 4A expression, cognitive performance and brain imaging measures in UK Biobank

Abstract.

BACKGROUND

Altered expression of the complement component C4A gene is a known risk factor for schizophrenia. Further, predicted brain C4A expression has also been associated with memory function highlighting that altered C4A expression in the brain may be relevant for cognitive and behavioral traits.

METHODS

We obtained genetic information and performance measures on seven cognitive tasks for up to 329 773 individuals from the UK Biobank, as well as brain imaging data for a subset of 33 003 participants. Direct genotypes for variants (n = 3213) within the major histocompatibility complex region were used to impute C4 structural variation, from which predicted expression of the C4A and C4B genes in human brain tissue were predicted. We investigated if predicted brain C4A or C4B expression were associated with cognitive performance and brain imaging measures using linear regression analyses.

RESULTS

We identified significant negative associations between predicted C4A expression and performance on select cognitive tests, and significant associations with MRI-based cortical thickness and surface area in select regions. Finally, we observed significant inconsistent partial mediation of the effects of predicted C4A expression on cognitive performance, by specific brain structure measures.

CONCLUSIONS

These results demonstrate that the C4 risk locus is associated with the central endophenotypes of cognitive performance and brain morphology, even when considered independently of other genetic risk factors and in individuals without mental or neurological disorders.

The association between anti-inflammatory effects of long-term lithium treatment and illness course in Bipolar Disorder

INTRODUCTION

Altered levels of acute-phase proteins are often described in different conditions in BD. Nevertheless, data on the association between lithium treatment and inflammatory markers in the long-term course of BD are still missing. The aim of the study was to examine the long-term course of BD concerning long-term lithium treatment, chronic inflammatory processes and symptom progression. Furthermore, the association between duration of lithium treatment and levels of hsCRP was explored.

METHODS

267 individuals (males= 139, females= 128) with BD were included. Duration of lithium treatment as well as symptom progression, defined as the increase in severity of symptoms, number of episodes a year and duration of episodes within a period of 1.5 years in the past and hsCRP were evaluated.

RESULTS

Male individuals with symptom progression over time had significantly lower duration of lithium treatment compared to individuals without symptoms progression (U= 47.4, p=.037). There were significantly higher levels of hsCRP in male individuals with symptom progression compared to males without symptom progression (U= 47.5, p=.027). Further, there was a significant negative correlation between the duration of lithium treatment and hsCRP levels in the whole sample (r= -.276, p<.05).

CONCLUSION

Our results show that an altered inflammatory state may be associated with a more severe illness course in BD. Further, a longer duration of lithium treatment may be associated with lower symptom progression. The shown association between hsCRP-levels and lithium treatment duration suggests a potential anti-inflammatory effect of lithium as a mediator of its significant positive outcome effect in BD.

The Role of Mitochondria in Mood Disorders: From Physiology to Pathophysiology and to Treatment

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher levels of oxidative stress. Recently, many agents capable of enhancing antioxidant defenses or mitochondrial functioning have been studied for the treatment of mood disorders as adjuvant therapy to current pharmacological treatments. A better knowledge of mitochondrial physiology and pathophysiology might allow the identification of new therapeutic targets and the development and study of novel effective therapies to treat these specific mitochondrial impairments. This could be especially beneficial for treatment-resistant patients. In this article, we provide a focused narrative review of the currently available evidence supporting the involvement of mitochondrial dysfunction in mood disorders, the effects of current therapies on mitochondrial functions, and novel targeted therapies acting on mitochondrial pathways that might be useful for the treatment of mood disorders.

SIGIRR and TNFAIP3 Are Differentially Expressed in Both PBMC and TNF-α Secreting Cells of Patients With Major Depressive Disorder

Background: Major depressive disorder (MDD) is associated with the activation of the immune/inflammatory system. TNF-α is associated with MDD and poor treatment response. Toll-like receptors (TLR) are responsible in innate immune response, and is associated with MDD and antidepressant response. Some negative regulators of TLR pathway such as SOCS1, TOLLIP, SIGIRR, TNFAIP3, and MyD88s, are reported to be differentially expressed in the peripheral blood samples of patients of MDD. Methods: We recruited patients with MDD and healthy controls, collect their demographic data, and measured their mRNA levels of negative TLR regulators, using peripheral blood mononuclear cells (PBMC) and isolated TNF-α secreting cells. Clinical symptoms were evaluated using Halmiton Depression Rating Scale (Ham-D). Some patients were evaluated again after 4 weeks of antidepressant treatment. Results: Forty-seven patients with MDD and 52 healthy controls were recruited. Between the PBMC samples of 37 MDD patients and 42 controls, mRNA levels of SOCS1, SIGIRR, TNFAIP3, and MyD88s were significantly different. Between TNF-α secreting cells of 10 MDD patients and 10 controls, mRNA levels of SIGIRR and TNFAIP3 were significantly different. Change of Ham-D score only correlated significantly with TOLLIP mRNA level after treatment. Conclusion: SIGIRR and TNFAIP3, two negative regulators of TLR immune response pathways, were differentially expressed in both PBMC and TNF-α secreting cells of patients with MDD as compared to healthy controls. The negative regulations of innate immune response could contribute to the underlying mechanism of MDD.

Expression of GSK3β, PICK1, NEFL, C4, NKCC1 and Synaptophysin in peripheral blood mononuclear cells of the first-episode schizophrenia patients

Schizophrenia (SZ) is a severe neurodevelopmental disease with unknown pathogenic mechanisms characterized with impaired cognitive function. The disturbed synaptic plasticity and synaptic loss have been widely reported in SZ. In this study, 41 first-episode schizophrenia (FES) patients and 44 healthy controls (HC) were recruited and the expression of six genes commonly relevant to synaptic functions was examined in the peripheral blood mononuclear cells (PBMCs). These genes were glycogen synthase kinase 3β (GSK3β), protein interacting with C-kinase 1 (PICK1), synaptophysin (SYP), neurofilament light (NEFL), complement component 4 (C4) and Na⁺-K^--2Cl^- cotransporter 1 (NKCC1). Real-time quantitative polymerase chain reaction (qPCR) was performed to determine the quantity of individual mRNA template. Compared to HC, the expression of PICK1 and NKCC1 genes in FES patients was relatively lower whereas the expression of NEFL was higher. No difference for the mRNA expression of GSK3β, SYP and C4 genes was detected between FES patients and HC, nor was the gender difference; Interestingly, the mRNA expression of PICK1 in female FES patients was significantly decreased compared to female HC, but not in males; and the NEFL gene was up-regulated in male FES patients but not in females. Our findings support an abnormal expression profile of synapse-related genes in the PBMCs of FES patients.

Inflammation Biomarkers in Psychiatry

Introduction:

There has long been a need for diagnostic, theragnostic, and prognostic biomarkers for psychiatric disorders. Biomarkers help in reducing ambiguity and arbitrariness and increase objectivity. In this context, many candidates for hormonal, immunological, serological, and neuroimaging markers have been proposed, but none of these marker candidates alone nor a biomarker panel has been approved for any disease. The fact that almost all psychiatric disorders are heterogeneous makes this process challenging. However, strong biomarker candidates have been identified, especially in light of the large number of clinical and preclinical studies conducted within the last five years.

Objective:

The aim of this article was to compile and discuss the current information on immune biomarkers in major psychiatric disorders, such as schizophrenia, depression, bipolar disorder, and anxiety disorders.

Methods:

In this study, respected scientific databases were searched using key terms related to the subject, and the related literature was examined in detail.

Results:

There are many relationships between psychiatric disorders and immune system parameters. Evidence also suggests that neuroinflammation is involved in the etiopathogenesis of psychiatric disorders. Markers, such as proinflammatory cytokines, tumor necrosis factor alpha, and C-reactive protein have been associated with psychiatric disorders in numerous studies.

Conclusions:

The neuroinflammation hypothesis has an important place in the etiopathogenesis of psychiatric disorders. Uncertainty remains as to whether neuroinflammation is a cause or consequence of psychiatric disorders. Some researchers have indicated that intestinal microbiota composition disorders and dysbiosis are sources of neuroinflammation. Immune marker studies are of great importance in terms of eliminating this uncertainty and overcoming diagnostic and treatment difficulties in the clinic. In this review, biomarker studies on psychiatric disorders were examined from the viewpoint of the immune system and discussed in light of the current studies.

Evidence for an enhanced procoagulant state in remitted major depression

OBJECTIVES

Hypercoagulability is one mechanism to explain the increased risk of incident atherothrombotic disease in patients with major depressive disorder (MDD). We examined whether patients with remitted MDD show an enhanced procoagulant state.

METHODS

63 individuals (median age 35 years, 59% women), 40 with a DSM-IV diagnosis of remitted MDD, made by a clinical interview, and 23 healthy controls provided blood samples for the measurement of fibrinogen, D-dimer, von Willebrand factor, and plasminogen activator inhibitor-1. Standardised z-scores of plasma levels of these haemostatic factors were added to form a procoagulant index (PCI) as the primary outcome variable. Self-ratings of residual depressive symptoms and trait anxiety were also obtained.

RESULTS

Compared with controls, remitted MDD patients had higher PCI (p = 0.013, Cohen's d = 0.69) and fibrinogen (p = 0.001, d = 0.91), controlling for age, sex, body mass index, smoking and C-reactive protein. There were no significant associations of the PCI and individual haemostatic molecules with age of MDD onset, time since the last MDD episode, the number of previous MDD episodes and residual depressive symptoms. Additional adjustment for anxiety symptoms did not change these results.

CONCLUSIONS

Remitted MDD is associated with an enhanced procoagulant state. Hypercoagulability seems more a trait than a state characteristic of depression.

Peripheral Markers of Depression

Major Depressive Disorder (MDD) is a leading cause of disability worldwide, creating a high medical and socioeconomic burden. There is a growing interest in the biological underpinnings of depression, which are reflected by altered levels of biological markers. Among others, enhanced inflammation has been reported in MDD, as reflected by increased concentrations of inflammatory markers-C-reactive protein, interleukin-6, tumor necrosis factor-α and soluble interleukin-2 receptor. Oxidative and nitrosative stress also plays a role in the pathophysiology of MDD. Notably, increased levels of lipid peroxidation markers are characteristic of MDD. Dysregulation of the stress axis, along with increased cortisol levels, have also been reported in MDD. Alterations in growth factors, with a significant decrease in brain-derived neurotrophic factor and an increase in fibroblast growth factor-2 and insulin-like growth factor-1 concentrations have also been found in MDD. Finally, kynurenine metabolites, increased glutamate and decreased total cholesterol also hold promise as reliable biomarkers for MDD. Research in the field of MDD biomarkers is hindered by insufficient understanding of MDD etiopathogenesis, substantial heterogeneity of the disorder, common co-morbidities and low specificity of biomarkers. The construction of biomarker panels and their evaluation with use of new technologies may have the potential to overcome the above mentioned obstacles.

High Mobility Group Protein 1 and Dickkopf-Related Protein 1 in Schizophrenia and Treatment-Resistant Schizophrenia: Associations With Interleukin-6, Symptom Domains, and Neurocognitive Impairments

BACKGROUND

Schizophrenia (SCZ) and treatment-resistant schizophrenia (TRS) are associated with aberrations in immune-inflammatory pathways. Increased high mobility group protein 1 (HMGB1), an inflammatory mediator, and Dickkopf-related protein (DKK1), a Wnt/β-catenin signaling antagonist, affect the blood-brain barrier and induce neurotoxic effects and neurocognitive deficits.

AIM

The present study aims to examine HMGB1 and DDK1 in nonresponders to treatments (NRTT) with antipsychotics (n = 60), partial RTT (PRTT, n = 55), and healthy controls (n = 43) in relation to established markers of SCZ, including interleukin (IL)-6, IL-10, and CCL11 (eotaxin), and to delineate whether these proteins are associated with the SCZ symptom subdomains and neurocognitive impairments.

RESULTS

HMGB1, DKK1, IL-6, and CCL11 were significantly higher in SCZ patients than in controls. DKK1 and IL-6 were significantly higher in NRTT than in PRTT and controls, while IL-10 was higher in NRTT than in controls. Binary logistic regression analysis showed that SCZ was best predicted by increased DDK1 and HMGB1, while NRTT (vs PRTT) was best predicted by increased IL-6 and CCL11 levels. A large part of the variance in psychosis, hostility, excitation, mannerism, and negative (PHEMN) symptoms and formal thought disorders was explained by HMGB1, IL-6, and CCL11, while most neurocognitive functions were predicted by HMGB1, DDK1, and CCL11.

CONCLUSIONS

The neurotoxic effects of HMGB1, DKK1, IL-6, and CCL11 including the effects on the blood-brain barrier and the Wnt/β-catenin signaling pathway may cause impairments in executive functions and working, episodic, and semantic memory and explain, in part, PHEMN symptoms and a nonresponse to treatment with antipsychotic drugs.

Galectin-1 and Galectin-3 Levels in Patients with Schizophrenia and their Unaffected Siblings

Many hypothesis suggest that inflammation plays an important role in schizophrenia. Galectins can regulate inflammatory response in central nervous system. The relation between galectins and neuropsyhchiatric diseases and schizophrenia is unclear. The present study compared levels of Gal-1 and Gal-3 of patients with schizophrenia to that of first-degree relatives without the disease and healthy controls in order to evaluate any possible association. Sixty-two patients with schizophrenia, fifty-five unaffected siblings and fifty-eight age- and sex-matched healthy controls enrolled. Serum Gal-1, Gal-3 and CRP levels were measured. PANNS and CGI-S were used to evaluate the severity of disease. There was a statistically significant difference in serum Gal-1 levels among the patient, sibling, and control groups. There were no statistically significant correlations between serum CRP ​​and serum Gal-1 or Gal-3 levels. Gal-1 values were significantly higher in the unaffected siblings compared to both the patient group and the healthy control group. Gal-3 levels were elevated in the sibling group relative to the patient group. In the literature, the relationship between galectins and schizophrenia is very limited and appears to be a new field of study. Future studies are needed to evaluate the protective roles of galectins.

Lowered Antioxidant Defenses and Increased Oxidative Toxicity Are Hallmarks of Deficit Schizophrenia: a Nomothetic Network Psychiatry Approach

There is now evidence that schizophrenia and deficit schizophrenia are neuro-immune conditions and that oxidative stress toxicity (OSTOX) may play a pathophysiological role. Aims of the study: to compare OSTOX biomarkers and antioxidant (ANTIOX) defenses in deficit versus non-deficit schizophrenia. We examined lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced oxidation protein products (AOPP), sulfhydryl (-SH) groups, paraoxonase 1 (PON1) activity and PON1 Q192R genotypes, and total radical-trapping antioxidant parameter (TRAP) as well as immune biomarkers in patients with deficit (n = 40) and non-deficit (n = 40) schizophrenia and healthy controls (n = 40). Deficit schizophrenia is characterized by significantly increased levels of AOPP and lowered -SH, and PON1 activity, while no changes in the OSTOX/ANTIOX biomarkers were found in non-deficit schizophrenia. An increased OSTOX/ANTIOX ratio was significantly associated with deficit versus non-deficit schizophrenia (odds ratio = 3.15, p < 0.001). Partial least squares analysis showed that 47.6% of the variance in a latent vector extracted from psychosis, excitation, hostility, mannerism, negative symptoms, psychomotor retardation, formal thought disorders, and neurocognitive test scores was explained by LOOH+AOPP, PON1 genotype + activity, CCL11, tumor necrosis factor (TNF)-α, and IgA responses to neurotoxic tryptophan catabolites (TRYCATs), whereas -SH groups and IgM responses to MDA showed indirect effects mediated by OSTOX and neuro-immune biomarkers. When overall severity of schizophrenia increases, multiple immune and oxidative (especially protein oxidation indicating chlorinative stress) neurotoxicities and impairments in immune-protective resilience become more prominent and shape a distinct nosological entity, namely deficit schizophrenia. The nomothetic network psychiatry approach allows building causal-pathway-phenotype models using machine learning techniques.