Effects of antipsychotic drugs on cytokine networks

A systematic review of clozapine-associated inflammation and related monitoring

Clozapine is an effective antipsychotic medication used for treatment-resistant schizophrenia. However, it is underutilized due to rigorous hematologic monitoring requirements and many adverse drug reactions. Publications have highlighted the occurrence of inflammatory reactions, some life-threatening, particularly during the early stages of clozapine treatment. Although guidelines have suggested monitoring for inflammatory processes during clozapine initiation, screening in clinical practice is not universal. This systematic review aimed to investigate the relationship between clozapine and inflammation and assess the importance of monitoring for inflammatory reactions. A comprehensive literature search yielded 6915 unique publication records after removal of duplicates. After a rigorous screening process, 75 publications were included in the review, which focused on three main aspects: (i) the impact of clozapine on inflammatory markers, (ii) monitoring cardiac and other organ function during clozapine-associated inflammatory processes, and (iii) monitoring non-specific signs and symptoms of inflammation. Elevated levels of C-reactive protein (CRP) and several proinflammatory cytokines have been observed in association with clozapine treatment. However, the practicality of measuring specific markers in clinical practice remains uncertain. Current evidence supports monitoring CRP levels during the first 4-8 weeks of treatment, especially to facilitate myocarditis screening. Further research is needed to establish clinically relevant CRP thresholds for intervention. The implementation of monitoring protocols during the early phase of clozapine treatment may mitigate adverse reactions and allow for continued use of clozapine. Future studies should also explore the association between clozapine-associated inflammation and pneumonia, as well as investigate the impact of inflammation on clozapine metabolism to predict the need for dose adjustment. These endeavors may facilitate the development and implementation of evidence-based guidelines for the monitoring of clozapine-associated inflammation.

Meta-analysis of soluble tumour necrosis factor receptors in severe mental illnesses

Tumour necrosis factor (TNF), as an innate immune defense molecule, functions through binding to TNF receptor 1 (TNFR1) or TNF receptor 2 (TNFR2). Peripheral levels of soluble TNFR1 (sTNFR1) and soluble TNFR2 (sTNFR2) were widely measured in severe mental illnesses (SMIs) including schizophrenia (SCZ), bipolar disorder (BD) and major depressive disorder (MDD) but inconsistencies existed. Hence, the present meta-analysis was conducted to identify the overall association between plasma/serum sTNFR1 and sTNFR2 levels and SMIs. Published studies were searched using Pubmed and Scopus. Data were analysed using Comprehensive Meta-Analysis version 2. Hedges's g effect sizes and 95% confidence intervals were pooled using fixed-effect or random-effects models. Heterogeneity, publication bias and study quality were assessed. Sensitivity analysis and subgroup analysis were performed. Our findings revealed that sTNFR1 level was significantly higher in SMI, particularly in BD. The sTNFR2 level significantly elevated in SMI but with smaller effect size. These findings further support the association between altered immune system and inflammatory abnormalities in SMI, especially in patients with BD. Subgroup analysis showed that younger age of onset, longer illness duration and psychotropic medication raised both sTNFR levels, especially sTNFR1, as these factors may contribute to the activation of inflammation. Future studies were suggested to identify the causality between TNFR pathway and SCZ, BD and MDD respectively using homogenous group of each SMI, and to determine the longitudinal effect of each psychotropic medication on TNFR pathway.

Anti-inflammatory effects of 2nd generation antipsychotics in patients with schizophrenia: A systematic review and meta-analysis

BACKGROUND

Schizophrenia is a major psychiatric disorder with unknown aetiology. Recent evidence suggests a potential role for cytokines in its pathophysiology and that antipsychotic medication may alter this. While the aetiology of schizophrenia remains only partly understood, an altered immune function representing an important avenue of further discovery. In this systematic review and meta-analysis we focus on the specific effects of second generation antipsychotics risperidone and clozapine on inflammatory cytokines.

METHODS

A defined systematic search of PubMed and Web of Science databases was performed to identify relevant studies published between Jan 1900 and May 2022. After screening of 2969 papers, 43 studies (27 single-arm and 8 dual-arm) were included that consisted of a total of 1421 patients with schizophrenia in the systematic review. From these, twenty studies (4 dual-arm; 678 patients) had data available on which a meta-analysis could be carried out.

RESULTS

Our meta-analysis showed a significant reduction of pro-inflammatory cytokines post-risperidone treatment in the absence of a similar association with clozapine. Subgroup analyses (First episode v chronic) demonstrated that duration of illness influenced the extent of cytokine alteration; risperidone treatment produced significant cytokine changes (lowered IL-6 and TNF-α) in chronic patients but not in first-episode psychosis (FEP) patients.

CONCLUSION

Varying treatment effects on cytokines can be observed by the use of different antipsychotic drugs. The cytokine alterations post-treatment are influenced by the specific antipsychotic drugs and patient status. This may explain disease progression in certain patient groups and influence therapeutic choices in the future.

Complement Activation Products in Patients with Chronic Schizophrenia

Evidence suggests a role of the immune system in the pathogenesis of a number of mental conditions, including schizophrenia (SCH). In terms of physiology, aside from its crucial protective function, the complement cascade (CC) is a critical element of the regeneration processes, including neurogenesis. Few studies have attempted to define the function of the CC components in SCH. To shed more light on this topic, we compared the levels of complement activation products (CAP) (C3a, C5a and C5b-9) in the peripheral blood of 62 patients with chronic SCH and disease duration of ≥ 10 years with 25 healthy controls matched for age, sex, BMI and smoking status. Concentrations of all the investigated CAP were elevated in SCH patients. However, after controlling for potential confounding factors, significant correlations were observed between SCH and C3a (M = 724.98 ng/mL) and C5a (M = 6.06 ng/mL) levels. In addition, multivariate logistic regression showed that C3a and C5b-9 were significant predictors of SCH. There were no significant correlations between any CAP and SCH symptom severity or general psychopathology in SCH patients. However, two significant links emerged between C3a and C5b-9 and global functioning. Increased levels of both complement activation products in the patient group as compared to healthy controls raise questions concerning the role of the CC in the etiology of SCH and further demonstrate dysregulation of the immune system in SCH patients.

Clozapine in a Young Female with Drug-Resistant Schizophrenia: A Case Report of Development of Serositis

BACKGROUND

Clozapine may be considered the first-line option for treatment-resistant schizophrenia (TRS), a condition that occurs in more than 30% of patients with schizophrenia. Despite its efficacy for treating TRS, clozapine use is limited by the occurrence of several adverse effects in more than 70% of cases. Clozapine does not typically affect lung function, although a few cases have been reported in the literature.

CASE PRESENTATION

To gain a better understanding of this rare event, here we report the case study of a young female with TRS, who was treated with clozapine and developed medium and bilateral pleural effusion relief with contiguous atelectasis and polyserositis. Two weeks after stopping clozapine, the follow-up chest scan showed complete remission of the pulmonary condition. We postulate that clozapine might have caused, in this case, a specific immunoinflammatory response leading to serosal complications.

CONCLUSION

Although the underlying mechanisms of this adverse effect are not completely understood, early manifestations, such as benign eosinophilia, fever, and flu-like symptoms need to be considered a potential warning to facilitate an early diagnosis and carefully manage pulmonary complications related to clozapine treatment.

Microglia sequelae: brain signature of innate immunity in schizophrenia

Schizophrenia is a psychiatric disorder with significant impact on individuals and society. The current pharmacologic treatment, which principally alleviates psychosis, is focused on neurotransmitters modulation, relying on drugs with severe side effects and ineffectiveness in a significant percentage of cases. Therefore, and due to difficulties inherent to diagnosis and treatment, it is vital to reassess alternative cellular and molecular drug targets. Distinct risk factors - genetic, developmental, epigenetic, and environmental - have been associated with disease onset and progression, giving rise to the proposal of different pathophysiological mechanisms and putative pharmacological targets. Immunity is involved and, particularly microglia - innate immune cells of the central nervous system, critically involved in brain development - have captured attention as cellular players. Microglia undergo marked morphologic and functional alterations in the human disease, as well as in animal models of schizophrenia, as reported in several original papers. We cluster the main findings of clinical studies by groups of patients: (1) at ultra-high risk of psychosis, (2) with a first episode of psychosis or recent-onset schizophrenia, and (3) with chronic schizophrenia; in translational studies, we highlight the time window of appearance of particular microglia alterations in the most well studied animal model in the field (maternal immune activation). The organization of clinical and translational findings based on schizophrenia-associated microglia changes in different phases of the disease course may help defining a temporal pattern of microglia changes and may drive the design of novel therapeutic strategies.

Inflammatory Subtypes in Antipsychotic-Naïve First-Episode Schizophrenia are Associated with Altered Brain Morphology and Topological Organization

BACKGROUND

Peripheral inflammation is implicated in schizophrenia, however, not all individuals demonstrate inflammatory alterations. Recent studies identified inflammatory subtypes in chronic psychosis with high inflammation having worse cognitive performance and displaying neuroanatomical enlargement compared to low inflammation subtypes. It is unclear if inflammatory subtypes exist earlier in the disease course, thus, we aim to identify inflammatory subtypes in antipsychotic naïve First-Episode Schizophrenia (FES).

METHODS

12 peripheral inflammatory markers, clinical, cognitive, and neuroanatomical measures were collected from a naturalistic study of antipsychotic-naïve FES patients. A combination of unsupervised principal component analysis and hierarchical clustering was used to categorize inflammatory subtypes from their cytokine data (17 FES High, 30 FES Low, and 33 healthy controls (HCs)). Linear regression analysis was used to assess subtype differences. Neuroanatomical correlations with clinical and cognitive measures were performed using partial Spearman correlations. Graph theoretical analyses were performed to assess global and local network properties across inflammatory subtypes.

RESULTS

The FES High group made up 36% of the FES group and demonstrated significantly greater levels of IL1β, IL6, IL8, and TNFα compared to FES Low, and higher levels of IL1β and IL8 compared to HCs. FES High had greater right parahippocampal, caudal anterior cingulate, and bank superior sulcus thicknesses compared to FES Low. Compared to HCs, FES Low showed smaller bilateral amygdala volumes and widespread cortical thickness. FES High and FES Low groups demonstrated less efficient topological organization compared to HCs. Individual cytokines and/or inflammatory signatures were positively associated with cognition and symptom measures.

CONCLUSIONS

Inflammatory subtypes are present in antipsychotic-naïve FES and are associated with inflammation-mediated cortical expansion. These findings support our previous findings in chronic psychosis and point towards a connection between inflammation and blood-brain barrier disruption. Thus, identifying inflammatory subtypes may provide a novel therapeutic avenue for biomarker-guided treatment involving anti-inflammatory medications.

Non-antipsychotic medicines and modified electroconvulsive therapy are risk factors for hospital-acquired pneumonia in schizophrenia patients

BACKGROUND

Hospital-acquired pneumonia (HAP) has a significant and detrimental impact on schizophrenia patients. Non-antipsychotic medicines and modified electroconvulsive therapy (MECT) are frequently used in conjunction with antipsychotics to treat schizophrenia. Whether non-antipsychotic medicines or MECT are risk factors for HAP in schizophrenia treated with antipsychotics is still unknown.

METHODS

Patients with schizophrenia who were admitted to the Fourth People's Hospital of Chengdu between January 2015 and April 2022 were included in this retrospective cohort study. Individuals with HAP were 1:1 matched to individuals without HAP (non-HAP) using propensity score matching (PSM). The risk factors for HAP were analyzed by comparing the two groups.

RESULTS

A total of 7,085 schizophrenia patients were included in this study, with a mean age of 39.77 ± 14.45 years. 193 patients developed HAP on an average of 22.26 ± 21.68 days after admission with an incidence of 2.73%. After 1:1 PSM, 192 patients from each group (HAP and non-HAP) were included. The HAP group had significantly more patients with MECT and taking benzodiazepines, antidepressants, mood stabilizers, and anti-parkinsonians both before and after PSM by Bonferroni correction (P < 0.001). Multivariate logistic regression analysis showed that, combined with antipsychotics, non-antipsychotic medicines including benzodiazepines (OR = 3.13, 95%CI = 1.95-5.03, P < 0.001), mood stabilizers (OR =3.33, 95%CI =1.79-6.20, P < 0.001) and MECT (OR =2.58, 95%CI =1.49-4.46, P = 0.001) were associated with a significantly increased incidence of HAP.

CONCLUSION

The incidence of HAP in schizophrenia patients in our cohort was 2.73%. MECT and non-antipsychotic medicines, including benzodiazepines and mood stabilizers were risk factors for HAP in schizophrenia patients treated with antipsychotics.

Drug-Induced Idiosyncratic Agranulocytosis - Infrequent but Dangerous

Drug-induced agranulocytosis is a life-threatening side effect that usually manifests as a severe form of neutropenia associated with fever or signs of sepsis. It can occur as a problem in the context of therapy with a wide variety of drug classes. Numerous drugs are capable of triggering the rare idiosyncratic form of agranulocytosis, which, unlike agranulocytosis induced by cytotoxic drugs in cancer chemotherapy, is characterised by “bizzare” type B or hypersensitivity reactions, poor predictability and a mainly low incidence. The idiosyncratic reactions are thought to be initiated by chemically reactive drugs or reactive metabolites that react with proteins and may subsequently elicit an immune response, particularly directed against neutrophils and their precursors. Cells or organs that exhibit specific metabolic and biotransformation activity are therefore frequently affected. In this review, we provide an update on the understanding of drug-induced idiosyncratic agranulocytosis. Using important triggering drugs as examples, we will summarise and discuss the chemical, the biotransformation-related, the mechanistic and the therapeutic basis of this clinically relevant and undesirable side effect.

Phenothiazine Inhibits Neuroinflammation and Inflammasome Activation Independent of Hypothermia After Ischemic Stroke

A depressive or hibernation-like effect of chlorpromazine and promethazine (C + P) on brain activity was reported to induce neuroprotection, with or without induced-hypothermia. However, the underlying mechanisms remain unclear. The current study evaluated the pharmacological function of C + P on the inhibition of neuroinflammatory response and inflammasome activation after ischemia/reperfusion. A total of 72 adult male Sprague-Dawley rats were subjected to 2 h middle cerebral artery occlusion (MCAO) followed by 6 or 24 h reperfusion. At the onset of reperfusion, rats received C + P (8 mg/kg) with temperature control. Brain cell death was detected by measuring CD68 and myeloperoxidase (MPO) levels. Inflammasome activation was measured by mRNA levels of NLRP3, IL-1β, and TXNIP, and protein quantities of NLRP3, IL-1β, TXNIP, cleaved-Caspase-1, and IL-18. Activation of JAK2/STAT3 pathway was detected by the phosphorylation of STAT3 (p-STAT3) and JAK2 (p-JAK2), and the co-localization of p-STAT3 and NLRP3. Activation of the p38 pathway was assessed with the protein levels of p-p38/p38. The mRNA and protein levels of HIF-1α, FoxO1, and p-FoxO1, and the co-localization of p-STAT3 with HIF-1α or FoxO1 were quantitated. As expected, C + P significantly reduced cell death and attenuated the neuroinflammatory response as determined by reduced CD68 and MPO. C + P decreased ischemia-induced inflammasome activation, shown by reduced mRNA and protein expressions of NLRP3, IL-1β, TXNIP, cleaved-Caspase-1, and IL-18. Phosphorylation of JAK2/STAT3 and p38 pathways and the co-localization of p-STAT3 with NLRP3 were also inhibited by C + P. Furthermore, mRNA levels of HIF-1α and FoxO1 were decreased in the C + P group. While C + P inhibited HIF-1α protein expression, it increased FoxO1 phosphorylation, which promoted the exclusion of FoxO1 from the nucleus and inhibited FoxO1 activity. At the same time, C + P reduced the co-localization of p-STAT3 with HIF-1α or FoxO1. In conclusion, C + P treatment conferred neuroprotection in stroke by suppressing neuroinflammation and NLRP3 inflammasome activation. The present study suggests that JAK2/STAT3/p38/HIF-1α/FoxO1 are vital regulators and potential targets for efficacious therapy following ischemic stroke.

Changes in the gut microbiome associated with infliximab in patients with bipolar disorder

OBJECTIVES

Available information exists supporting the gut-brain axis, but additional information is needed to explore how the gut microbiome changes when exposed to mood disorder treatments. We sought to explore the effects of a novel treatment for bipolar disorder (BD), infliximab, on the gut microbiome.

METHODS

Participants with a primary diagnosis of BD (n = 15) who participated in a 12-week, randomized placebo-controlled trial evaluating the efficacy of adjunctive infliximab in the treatment of BD were recruited and followed. Stool samples were collected prior to randomization and at 12 weeks. 16S rRNA sequencing was employed in order to analyze the gut microbial community profile.

RESULTS

A total of 17 participants were randomized to infliximab (n = 9; mean [SD] age, 47.6 [10.3] years; 8 female) or to placebo (n = 8; mean [SD] age, 45.9 [10.7] years; 7 female) but two participants from the infliximab group were lost to follow-up post randomization. Across all time points, there were no differences in the diversity on either Shannon or Simpson's Diversity indices. Comparison of Aitchison distances revealed a lack of clustering of the microbiota by time point, but did reveal a small overall effect of treatment that was not significantly different at individual time points. There were also no effects of either time or treatment on differential abundance at either the amplicon sequence variant or genus level.

CONCLUSIONS

These observations indicate that no community-wide changes in the microbiota diversity and profile were detected after the use of infliximab treatment.

Association of mental disorders with SARS-CoV-2 infection and severe health outcomes: nationwide cohort study

BACKGROUND

Epidemiological data on the association between mental disorders and the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) severity are limited.

AIMS

To evaluate the association between mental disorders and the risk of SARS-CoV-2 infection and severe outcomes following COVID-19.

METHOD

We performed a cohort study using the Korean COVID-19 patient database based on national health insurance data. Each person with a mental or behavioural disorder (diagnosed during the 6 months prior to their first SARS-CoV-2 test) was matched by age, gender and Charlson Comorbidity Index with up to four people without mental disorders. SARS-CoV-2-positivity risk and the risk of death or severe events (intensive care unit admission, use of mechanical ventilation and acute respiratory distress syndrome) post-infection were calculated using conditional logistic regression analysis.

RESULTS

Among 230 565 people tested for SARS-CoV-2, 33 653 (14.6%) had mental disorders; 928/33 653 (2.76%) tested SARS-CoV-2 positive and 56/928 (6.03%) died. In multivariable analysis using the matched cohort, there was no association between mental disorders and SARS-CoV-2-positivity risk (odds ratio OR = 0.95; 95% CI 0.87-1.04); however, a higher risk was associated with schizophrenia-related disorders (OR = 1.50; 95% CI 1.14-1.99). Among confirmed COVID-19 patients, the mortality risk was significantly higher in patients with than in those without mental disorders (OR = 1.99, 95% CI 1.15-3.43).

CONCLUSIONS

Mental disorders are likely contributing factors to mortality following COVID-19. Although the infection risk was not higher for people with mental disorders overall, those with schizophrenia-related disorders were more vulnerable to infection.

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.

Human macrophages stimulate expression of inflammatory mediators in adipocytes; effects of second-generation antipsychotics and glucocorticoids on cellular cross-talk

OBJECTIVE

Adipose tissue inflammation and distorted macrophage-adipocyte communication are positively associated with metabolic disturbances. Some pharmacological agents, such as second-generation antipsychotics (SGAs) and synthetic glucocorticoid (GC) dexamethasone, tend to induce adverse metabolic side effects and the underlying mechanisms are not fully understood. Our work aimed to study whether SGAs and dexamethasone affect macrophage phenotype and macrophage-adipocyte communication on gene expression level. We selected the model involving THP-1-derived macrophages, polarized into M0, M1, and M2 phenotypes, and primary human mature subcutaneous adipocytes.

METHODS

Abdominal subcutaneous adipose tissue needle biopsies were obtained from 6 healthy subjects (4F/2M; age: 22-64 yr; BMI: 21.7-27.6 kg/m2) followed by isolation of mature adipocytes. THP-1-human monocytic cell line was used for the study. THP-1 monocytes were differentiated and polarized into M0 (naïve), M1 (classically activated), and M2 (alternatively activated) macrophages. During and after polarization the macrophages were treated for 24 h without (control) or with therapeutic and supra-therapeutic concentrations of olanzapine (0.2 µM and 2.0 µM), aripiprazole (1.0 µM and 10 µM) and its active metabolite dehydroaripiprazole (0.4 µM and 4.0 µM). Isolated mature human adipocytes were co-incubated with THP-1-derived polarized macrophages pre-treated with SGAs after their polarization. Adipocytes and macrophages were collected before and after co-culture for mRNA expression analysis of genes involved in inflammation.

RESULTS

Co-incubation of mature human adipocytes with human macrophages, regardless of polarization, resulted in a marked induction of pro-inflammatory cytokines in adipocytes, including IL1B, IL6, TNFA, and IL10. Remarkably, it did not affect the expression of adipokines and genes involved in the regulation of energy, lipid, and glucose metabolism in adipocytes. Dexamethasone markedly reduced gene expression of pro-inflammatory cytokines in macrophages and prevented macrophage-induced inflammatory response in adipocytes. In contrast, SGAs did not affect macrophage-adipocyte communication and had a minute anti-inflammatory effect in macrophages at supra-therapeutic concentrations. Interestingly, the adipocytes co-incubated with M1 macrophages pre-treated with dexamethasone and SGAs particularly the supra-therapeutic concentration of olanzapine, reduced expression of LPL, LIPE, AKT1, and SLC2A4, suggesting that the expression of metabolic genes in adipocytes was dependent on the presence of pro-inflammatory M1 macrophages.

CONCLUSION

Together, these data suggest that macrophages induce expression of pro-inflammatory genes in human subcutaneous adipocytes without affecting the expression of adipokines or genes involved in energy regulation. Furthermore, our findings demonstrated that SGAs and dexamethasone had a mild effect on macrophage-adipocyte communication in M1 macrophage phenotype.

Safety of antipsychotic drugs: A systematic review of disproportionality analysis studies

Antipsychotic drugs are commonly prescribed, mainly for the treatment of schizophrenia and other psychotic disorders. Disproportionality analysis of pharmacovigilance data from national and international databases have been recently utilized to investigate the side-effect profiles of antipsychotics and have provided unique insights of their safety. Among several national and international spontaneous reporting databases the databases of the World Health Organization (VigiBase), of the European Medicines Agency (EudraVigilance) and the US Food and Drug Administration (FAERS) incorporate millions of Individual Case Safety Reports. The aim of our study was to systematically review published disproportionality analyses on antipsychotic drugs, in order to summarize the current state of methodology and potential strengths of this analysis while highlighting safety signal generated for these pharmacological group. PubMed was searched using a search algorithm combining terms for antipsychotic drugs and disproportionality analysis. A total of 39 articles were found to be eligible corresponding to 38 original disproportionality studies. Different measures of disproportionality were used in each study: reporting odds ratio (ROR), proportional reporting ratio (PRR), empirical Bayes geometric mean (EBGM) and the information component (IC). Despite the inherent limitations of the pharmacovigilance databases disproportionality analysis provides complemented evidence from RCTs on the safety of antipsychotics, especially regarding participants often excluded from RCTs, such as pregnant and breastfeeding women, children and participants with drug abuse, comorbidities or concomitant medications.

Dopamine D1 Receptor in Cancer

Simple Summary

Circulating hormones and their specific receptors play a significant role in the development and progression of various cancers. This review aimed to summarize current knowledge about the dopamine D1 receptor’s biological role in different cancers, including breast cancer, central nervous system tumors, lymphoproliferative disorders, and other neoplasms. Treatment with dopamine D1 receptor agonists was proven to exert a major anti-cancer effect in many preclinical models. We highlight this receptor’s potential as a target for the adjunct therapy of tumors and discuss possibilities and necessities for further research in this area.

Abstract

Dopamine is a biologically active compound belonging to catecholamines. It plays its roles in the human body, acting both as a circulating hormone and neurotransmitter. It acts through G-protein-coupled receptors divided into two subgroups: D1-like receptors (D1R and D5R) and D2-like receptors (D2R, D3R, D4R). Physiologically, dopamine receptors are involved in central nervous system functions: motivation or cognition, and peripheral actions such as blood pressure and immune response modulation. Increasing evidence indicates that the dopamine D1 receptor may play a significant role in developing different human neoplasms. This receptor’s value was presented in the context of regulating various signaling pathways important in tumor development, including neoplastic cell proliferation, apoptosis, autophagy, migration, invasiveness, or the enrichment of cancer stem cells population. Recent studies proved that its activation by selective or non-selective agonists is associated with significant tumor growth suppression, metastases prevention, and tumor microvasculature maturation. It may also exert a synergistic anti-cancer effect when combined with tyrosine kinase inhibitors or temozolomide. This review provides a comprehensive insight into the heterogeneity of dopamine D1 receptor molecular roles and signaling pathways in human neoplasm development and discusses possible perspectives of its therapeutic targeting as an adjunct anti-cancer strategy of treatment. We highlight the priorities for further directions in this research area.

Peripheral complement proteins in schizophrenia: A systematic review and meta-analysis of serological studies

BACKGROUND

There is renewed focus on the complement system in the pathogenesis of schizophrenia. In addition to providing aetiological insights, consistently dysregulated complement proteins in serum or plasma may have clinical utility as biomarkers.

METHODS

We performed a systematic literature review searching PubMed, Embase and PsycINFO for studies measuring complement system activity or complement protein concentrations in serum or plasma from patients with schizophrenia compared to controls. Random-effects meta-analyses were performed to calculate pooled effect estimates (Hedges' g standardised mean difference [SMD]) for complement proteins whose concentrations were measured in three or more studies. The review was pre-registered on the PROSPERO database (CRD42018109012).

RESULTS

Database searching identified 1146 records. Fifty-eight full-text articles were assessed for eligibility and 24 studies included. Seven studies measured complement system activity. Activity of the classical pathway did not differ between cases and controls in four of six studies, and conflicting results were noted in two studies of alternative pathway activity. Twenty studies quantified complement protein concentrations of which complement components 3 (C3) and 4 (C4) were measured in more than three studies. Meta-analyses showed no evidence of significant differences between cases and controls for 11 studies of C3 (SMD 0.04, 95% confidence interval [CI] -0.29-0.36) and 10 studies of C4 (SMD 0.10, 95% CI -0.21-0.41).

CONCLUSIONS

Serological studies provide mixed evidence regarding dysregulation of the complement system in schizophrenia. Larger studies of a longitudinal nature, focusing on early phenotypes, could provide further insights regarding the potential role of the complement system in psychotic disorders.

Repurposing chlorpromazine to treat COVID-19: The reCoVery study

OBJECTIVES

The ongoing COVID-19 pandemic has caused approximately 2,350,000 infections worldwide and killed more than 160,000 individuals. In Sainte-Anne Hospital (GHU PARIS Psychiatrie & Neuroscience, Paris, France) we have observed a lower incidence of symptomatic forms of COVID-19 among patients than among our clinical staff. This observation led us to hypothesize that psychotropic drugs could have a prophylactic action against SARS-CoV-2 and protect patients from the symptomatic and virulent forms of this infection, since several of these psychotropic drugs have documented antiviral properties. Chlorpromazine (CPZ), a phenothiazine derivative, is also known for its antiviral activity via the inhibition of clathrin-mediated endocytosis. Recentin vitro studies have reported that CPZ exhibits anti-MERS-CoV and anti-SARS-CoV-1 activity.

METHODS

In this context, the ReCoVery study aims to repurpose CPZ, a molecule with an excellent tolerance profile and a very high biodistribution in the saliva, lungs and brain. We hypothesize that CPZ could reduce the unfavorable course of COVID-19 infection among patients requiring respiratory support without the need for ICU care, and that it could also reduce the contagiousness of SARS-CoV-2. For this purpose, we plan a pilot, multicenter, randomized, single blind, controlled, phase III therapeutic trial (standard treatment vs. CPZ+standard treatment).

CONCLUSION

This repurposing of CPZ for its anti-SARS-CoV-2 activity could offer an alternative, rapid strategy to alleviate infection severity. This repurposing strategy also avoids numerous developmental and experimental steps, and could save precious time to rapidly establish an anti-COVID-19 therapy with well-known, limited and easily managed side effects.

[Repurposing of chlorpromazine in COVID-19 treatment: the reCoVery study]

OBJECTIVES

The ongoing COVID-19 pandemic comprises a total of more than 2,350,000 cases and 160,000 deaths. The interest in anti-coronavirus drug development has been limited so far and effective methods to prevent or treat coronavirus infections in humans are still lacking. Urgent action is needed to fight this fatal coronavirus infection by reducing the number of infected people along with the infection contagiousness and severity. Since the beginning of the COVID-19 outbreak several weeks ago, we observe in GHU PARIS Psychiatrie & Neurosciences (Sainte-Anne hospital, Paris, France) a lower prevalence of symptomatic and severe forms of COVID-19 infections in psychiatric patients (∼4%) compared to health care professionals (∼14%). Similar observations have been noted in other psychiatric units in France and abroad. Our hypothesis is that psychiatric patients could be protected from severe forms of COVID-19 by their psychotropic treatments. Chlorpromazine (CPZ) is a phenothiazine derivative widely used in clinical routine in the treatment of acute and chronic psychoses. This first antipsychotic medication has been discovered in 1952 by Jean Delay and Pierre Deniker at Sainte-Anne hospital. In addition, to its antipsychotic effects, several in vitro studies have also demonstrated a CPZ antiviral activity via the inhibition of clathrin-mediated endocytosis. Recently, independent studies revealed that CPZ is an anti-MERS-CoV and an anti-SARS-CoV-1 drug. In comparison to other antiviral drugs, the main advantages of CPZ lie in its biodistribution: (i) preclinical and clinical studies have reported a high CPZ concentration in the lungs (20-200 times higher than in plasma), which is critical because of the respiratory tropism of SARS-CoV-2; (ii) CPZ is highly concentrated in saliva (30-100 times higher than in plasma) and could therefore reduce the contagiousness of COVID-19; (iii) CPZ can cross the blood-brain barrier and could therefore prevent the neurological forms of COVID-19.

METHODS

Our hypothesis is that CPZ could decrease the unfavorable evolution of COVID-19 infection in oxygen-requiring patients without the need for intensive care, but also reduce the contagiousness of SARS-CoV-2. At this end, we designed a pilot, phase III, multicenter, single blind, randomized controlled clinical trial. Efficacy of CPZ will be assessed according to clinical, biological and radiological criteria. The main objective is to demonstrate a shorter time to response (TTR) to treatment in the CPZ+standard-of-care (CPZ+SOC) group, compared to the SOC group. Response to treatment is defined by a reduction of at least one level of severity on the WHO-Ordinal Scale for Clinical Improvement (WHO-OSCI). The secondary objectives are to demonstrate in the CPZ+SOC group, compared to the SOC group: (A) superior clinical improvement; (B) a greater decrease in the biological markers of viral attack by SARS-CoV-2 (PCR, viral load); (C) a greater decrease in inflammatory markers (e.g. CRP and lymphopenia); (D) a greater decrease in parenchymal involvement (chest CT) on the seventh day post-randomization; (E) to define the optimal dosage of CPZ and its tolerance; (F) to evaluate the biological parameters of response to treatment, in particular the involvement of inflammatory cytokines. Patient recruitment along with the main and secondary objectives are in line with WHO 2020 COVID-19 guidelines.

CONCLUSION

This repositioning of CPZ as an anti-SARS-CoV-2 drug offers an alternative and rapid strategy to alleviate the virus propagation and the infection severity and lethality. This CPZ repositioning strategy also avoids numerous developmental and experimental steps and can save precious time to rapidly establish an anti-COVID-19 therapy with well-known, limited and easy to manage side effects. Indeed, CPZ is an FDA-approved drug with an excellent tolerance profile, prescribed for around 70 years in psychiatry but also in clinical routine in nausea and vomiting of pregnancy, in advanced cancer and also to treat headaches in various neurological conditions. The broad spectrum of CPZ treatment - including antipsychotic, anxiolytic, antiemetic, antiviral, immunomodulatory effects along with inhibition of clathrin-mediated endocytosis and modulation of blood-brain barrier - is in line with the historical French commercial name for CPZ, i.e. LARGACTIL, chosen as a reference to its "LARGe ACTion" properties. The discovery of those CPZ properties, as for many other molecules in psychiatry, is both the result of serendipity and careful clinical observations. Using this approach, the field of mental illness could provide innovative therapeutic approaches to fight SARS-CoV-2.

Inflammation in psychiatric disorders

One of the most promising research fields is the inflammatory component of major psychiatric diseases (depression, bipolar disorders and schizophrenia). Multiple recent reviews clearly demonstrate that depression, schizophrenia and bipolar disorder are associated with a dysregulation of immune responses as reflected by the observed abnormal profiles of circulating pro- and anti-inflammatory cytokines in affected patients. Considering the high rate of associated somatic comorbidity, major mental illnesses, especially bipolar disorders, have been proposed as multi-systemic inflammatory diseases affecting the brain as well as other organs. In parallel, chronic inflammatory diseases are known to have a high psychiatric comorbidity rate (especially with depression). The same overlap is also found in pharmacological drugs properties as several antidepressants (especially selective serotonin reuptake inhibitors), several antipsychotics and mood stabilizers have shown intrinsic anti-inflammatory properties [1,2]. We recently conducted a systematic review of the literature regarding the efficacy of anti-inflammatory drugs (classified according to their mechanisms of action) in MDD, schizophrenia and bipolar disorders) [3]. We found that polyunsaturated fatty acids (PUFAs) have anti-inflammatory properties and are effective in major depression with a good tolerance profile. One meta-analysis based on 5 trials indicated that COX-2 specific inhibitors showed effectiveness in schizophrenia. COX-1 inhibitors like low-dose aspirin may also have potential effectiveness in the three major disorders but further studies are warranted. Minocycline, an antibiotic that penetrates central nervous system, showed also effectiveness in schizophrenia. Anti-TNFalpha drugs showed important effectiveness in resistant depression with blood inflammatory abnormalities, but in only one randomized placebo-controlled trial [4]. However, in this trial, the anti-inflammatory drug was much more effective than classical antidepressants in patients with baseline elevated hs-CRP (a inflammatory marker).

Psychotropic Drug-Associated Pneumonia in Older Adults

The use of psychotropic drugs (antipsychotics, benzodiazepines and benzodiazepine-related drugs, and antidepressants) is common, with a prevalence estimates range of 19-29% among community dwelling older adults. These drugs are often prescribed for off-label use, including neuropsychiatric symptoms. The older adult population also has high rates of pneumonia and some of these cases may be associated with adverse drug events. In this narrative review, we summarize the findings from current observational studies on the association between psychotropic drug use and pneumonia in older adults. In addition to studies assessing the use of psychotropics, we included antiepileptic drugs, as they are also central nervous system-acting drugs, whose use is becoming more common in the aging population. The use of antipsychotics, benzodiazepine, and benzodiazepine-related drugs are associated with increased risk of pneumonia in older adults (≥ 65 years of age), and these findings are not limited to this age group. Minimal and conflicting evidence has been reported on the association between antidepressant drug use and pneumonia, but differences between study populations make it difficult to compare findings. Studies regarding antiepileptic drug use and risk of pneumonia in older persons are lacking, although an increased risk of pneumonia in antiepileptic drug users compared with non-users in persons with Alzheimer's disease has been reported. Tools such as the American Geriatric Society Beers Criteria and the STOPP/START criteria for potentially inappropriate medications aids prescribers to avoid these drugs in order to reduce the risk of adverse drug events. However, risk of pneumonia is not mentioned in the current criteria and more research on this topic is needed, especially in vulnerable populations, such as persons with dementia.

A Meta-analysis of Immune Parameters, Variability, and Assessment of Modal Distribution in Psychosis and Test of the Immune Subgroup Hypothesis

Immune parameters are elevated in psychosis, but it is unclear whether alterations are homogenous across patients or heterogeneity exists, consistent with the hypothesis that immune alterations are specific to a subgroup of patients. To address this, we examine whether antipsychotic-naïve first-episode psychosis patients exhibit greater variability in blood cytokines, C-reactive protein, and white cell counts compared with controls, and if group mean differences persist after adjusting for skewed data and potential confounds. Databases were searched for studies reporting levels of peripheral immune parameters. Means and variances were extracted and analyzed using multivariate meta-analysis of mean and variability of differences. Outcomes were (1) variability in patients relative to controls, indexed by variability ratio (VR) and coefficient of variation ratio (CVR); (2) mean differences indexed by Hedges g; (3) Modal distribution of raw immune parameter data using Hartigan's unimodality dip test. Thirty-five studies reporting on 1263 patients and 1470 controls were included. Variability of interleukin-6 (IL6) (VR = 0.19), tumor necrosis factor-α (TNFα) (VR = 0.36), interleukin-1β (VR = 0.35), interleukin-4 (VR = 0.55), and interleukin-8 (VR = 0.28) was reduced in patients. Results persisted for IL6 and IL8 after mean-scaling. Ninety-four percent and one hundred percent of raw data were unimodally distributed in psychosis and controls, respectively. Mean levels of IL6 (g = 0.62), TNFα (g = 0.56), interferon-γ (IFNγ) (g = 0.32), transforming growth factor-β (g = 0.53), and interleukin-17 (IL17) (g = 0.48) were elevated in psychosis. Sensitivity analyses indicated this is unlikely explained by confounders for IL6, IFNγ, and IL17. These findings show elevated cytokines in psychosis after accounting for confounds, and that the hypothesis of an immune subgroup is not supported by the variability or modal distribution.

Neurobiology and Therapeutic Potential of Cyclooxygenase-2 (COX-2) Inhibitors for Inflammation in Neuropsychiatric Disorders

Neuropsychiatric disorders, such as depression, bipolar disorder, schizophrenia, obsessive-compulsive disorder, and neurodevelopmental disorders such as autism spectrum disorder, are associated with significant illness burden. Accumulating evidence supports an association between these disorders and inflammation. Consequently, anti-inflammatory agents, such as the cyclooxygenase-2 inhibitors, represent a novel avenue to prevent and treat neuropsychiatric illness. In this paper, we first review the role of inflammation in psychiatric pathophysiology including inflammatory cytokines' influence on neurotransmitters, the hypothalamic-pituitary-adrenal axis, and microglial mechanisms. We then discuss how cyclooxygenase-2-inhibitors influence these pathways with potential therapeutic benefit, with a focus on celecoxib, due to its superior safety profile. A search was conducted in PubMed, Embase, and PsychINFO databases, in addition to Clinicaltrials.gov and the Stanley Medical Research Institute trial registries. The results were presented as a narrative review. Currently available outcomes for randomized controlled trials up to November 2017 are also discussed. The evidence reviewed here suggests cyclooxygenase-2 inhibitors, and in particular celecoxib, may indeed assist in treating the symptoms of neuropsychiatric disorders; however, further studies are required to assess appropriate illness stage-related indication.

Relationships between sleep patterns and metabolic profile in patients maintained on antipsychotics: a cross-sectional comparative study

BACKGROUND

Disturbances in sleep duration and quality have been associated with obesity and other metabolic changes. Patients with mental disorders (MD) are known to have more sleep problems, and antipsychotics (AP), used in the treatment of these patients, can also cause weight gain. This study aimed to compare the self-reported sleep patterns between psychiatric patients (on or off AP) and controls. We also evaluated the associations between the clinical and metabolic profiles with short or long sleep duration.

METHODS

A total of 339 subjects was recruited: Mentally ill patients maintained on AP for at least six months (MD+AP, n=112), patients not taking AP for at least the last six months before enrollment (MD/noAP, n=101), and non-psychiatry controls (HC, n=126). Multinomial regression analysis was applied to find the predictors of irregular sleep duration in this sample.

RESULTS

More mentally ill patients (MD+AP and MD/noAP) reported a sleep duration of >8 hrs than HC. Patients from MD/noAP showed more insomnia than HC. Sleep disturbances were significantly more frequent in MD+AP than HC. Participants who reported sleeping >8 hrs had higher body mass index and waist circumference than those who slept <7 hrs.

CONCLUSION

Female gender, central obesity and being mentally ill were independently associated with long sleep duration (>8h) in the population of Qatar.

Second generation atypical antipsychotics olanzapine and aripiprazole reduce expression and secretion of inflammatory cytokines in human immune cells

Schizophrenia and major depression are associated with alterations in peripheral inflammatory markers, and anti-inflammatory therapy has been proposed as a promising add-on approach in the pharmacologic treatment of both disorders. Second-generation atypical antipsychotics are currently first-line drugs in the treatment of schizophrenia and are also used as augmentation strategies in treatment-resistant major depression. Furthermore, these drugs have been reported to exhibit distinct metabolic side effects and to influence inflammatory processes. In this study, we used ex vivo stimulation of primary human peripheral blood mononuclear cells (PBMC) from healthy blood donors with atypical antipsychotics olanzapine or aripiprazole to examine effects on cytokine production independent from metabolic side effects and disease status. Both olanzapine and aripiprazole stimulation decreased mRNA levels of IL-1β, IL-6, and TNF-α and resulted in diminished protein concentrations of IL-6 and TNF-α in conditioned medium of stimulated PBMC. A multiplex approach revealed additional downregulation of IL-2; MIP-1β and IP-10 secretion. Similarly, olanzapine and aripiprazole stimulation of the human monocytic cell line THP-1 resulted in a significant decrease in expression and secretion of IL-1β and TNF-α. Our results suggest that atypical antipsychotics directly influence immune cell function and thereby highlight the importance to factor in potential side effects of drugs routinely used in treatment of schizophrenia and major depression on inflammatory processes when considering anti-inflammatory drug therapy as an additional treatment option.

Cardiovascular Safety of Psychiatric Agents: A Cautionary Tale

Psychiatric agents are among the most commonly prescribed medications. Despite the advent of newer generation agents, patients receiving them still experience cardiovascular (CV) side effects. However, these agents may have heterogeneous properties, calling for an individualized approach based on efficacy and also on the particular side effect profile of each specific agent. Proarrhythmic effects arising from drug-induced long-QT syndrome and consequent potentially life-threatening polymorphic ventricular arrhythmias in the form of torsade de pointes, the metabolic syndrome contributing to atherosclerosis and acute coronary syndromes, and drug-induced orthostatic hypotension raise major concerns. Of course, it is also crucial that fear of potential CV adverse effects does not deprive psychiatric patients of appropriate drug therapy. Modification of CV risk factors in psychiatric patients together with optimal management of their CV diseases and appropriate selection of psychotropic agents with greater efficacy and least CV toxicity are of paramount importance in mitigating CV risks and enhancing safety. Identifying patients at high risk of CV complications and close monitoring of all patients receiving these agents are crucial steps to prevent and manage such complications. All these issues are herein reviewed, relevant guidelines are discussed, and schemas are depicted that illustrate the interrelated connections among the psychotropic agents and their CV effects.

Clozapine reduces Toll-like receptor 4/NF-κB-mediated inflammatory responses through inhibition of calcium/calmodulin-dependent Akt activation in microglia

Clozapine is an atypical antipsychotic agent used in the treatment of schizophrenia and severe mood disorders. Accumulating evidence suggests that neuroinflammation is closely associated with the pathogenesis of various neurodegenerative diseases and psychiatric disorders. Clozapine exerts anti-inflammatory activity. However, the molecular mechanism underlying the anti-inflammatory activity of clozapine is poorly understood. In this study, we found that clozapine suppressed lipopolysaccharide (LPS)-induced phosphorylation of IκBα at Ser-32 and of p65/RelA at Ser-468, as well as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-dependent transcriptional activity in microglial cells. Clozapine downregulated LPS-induced Akt phosphorylation at Ser-473. Pharmacological Akt inhibitors ameliorated LPS-induced NF-κB activation. Removal of extracellular Ca²⁺ by EGTA or sequestration of intracellular Ca²⁺ by BAPTA-AM attenuated LPS-induced Akt phosphorylation. Treatment with calmodulin (CaM) antagonists and the CaM kinase inhibitor, KN-93, also prevented LPS-induced Akt and NF-κB activation, suggesting that Ca²⁺/CaM-dependent Akt activation is critical in LPS-induced NF-κB activation in microglia. These results suggest that clozapine exhibits anti-inflammatory activity through the inhibition of Ca²⁺/CaM/Akt-mediated NF-κB activation.

Interleukin-6 in Schizophrenia-Is There a Therapeutic Relevance?

Renewing interest in immune aspects of schizophrenia and new findings about the brain-fat axis encourage us to discuss the possible role of interleukin-6 (IL-6) in schizophrenia. Previously, it was suggested that a primary alteration of the innate immune system may be relevant in schizophrenia. Functional dichotomy of IL-6 suggests that this chemical messenger may be responsible for regulating the balance between pro- and anti-inflammatory responses, with tissue-specific properties at the periphery and in the central nervous system. Specific phase of this chronic and deteriorating disorder must be considered, which can involve IL-6 in acute or possible chronic inflammation and/or autoimmunity. We give an overview of IL-6 role in the onset and progression of this disorder, also considering cognitive impairment and metabolic changes in patients with schizophrenia. Data suggest that decreased serum level of IL-6 following antipsychotic therapy could be predisposing factor for the development of obesity and obesity-related metabolic disorders in schizophrenia. As we reviewed, the IL-6 plays significant role in disease genesis and progression, so the use of specific inhibitors may not only be beneficial for exacerbation and alleviation of positive symptoms, but may attenuate cognitive impairment in patients with schizophrenia.

Clozapine Associated with Autoimmune Reaction, Fever and Low Level Cardiotoxicity - A Case Report

BACKGROUND

Clozapine is a second-generation antipsychotic drug used in treatment-resistant schizophrenia. Fever induced by clozapine is a rather frequent side-effect which usually occurs in the first 4 weeks of treatment. Despite its effectiveness, there are potentially life-threatening adverse effects, such as cardiotoxicity.

CASE REPORT

We present the case of a 31-year-old caucasian male with refractory schizophrenia who developed benign fever, increase of C-reactive protein and high troponin levels, without presenting any other signs to myocarditis, on the 13th day under clozapine treatment, which declined progressively upon discontinuation of the drug.

DISCUSSION

This case hints at the presence of initially subclinical cardiotoxicity as an underlying factor in patients developing fever.

CONCLUSION

Taking advantage of more sensitive methods for measuring troponin, clinicians would be promptly aware of this possible side-effect. This would allow for significant reduction of the risk of cardiac dysfunction, further attained by carefully monitoring the patient.

Volume, metabolites and neuroinflammation of the hippocampus in bipolar disorder - A combined magnetic resonance imaging and positron emission tomography study

BACKGROUND

The hippocampus is one of the brain regions that is involved in several pathophysiological theories about bipolar disorder (BD), such as the neuroinflammation theory and the corticolimbic metabolic dysregulation theory. We compared hippocampal volume and hippocampal metabolites in bipolar I disorder (BD-I) patients versus healthy controls (HCs) with magnetic resonance imaging (MRI) and spectroscopy (MRS). We post hoc investigated whether hippocampal volume and hippocampal metabolites were associated with microglial activation and explored if potential illness modifying factors affected these hippocampal measurements and whether these were associated with experienced mood and functioning.

MATERIALS AND METHODS

Twenty-two BD-I patients and twenty-four HCs were included in the analyses. All subjects underwent psychiatric interviews as well as an MRI scan, including a T1 scan and PRESS magnetic resonance spectroscopy (MRS). Volumetric analysis was performed with Freesurfer. MRS quantification was performed with LC Model. A subgroup of 14 patients and 11 HCs also underwent a successful [(11)C]-(R)-PK11195 neuroinflammation positron emission tomography scan.

RESULTS

In contrast to our hypothesis, hippocampal volumes were not decreased in patients compared to HC after correcting for individual whole-brain volume variations. We demonstrated decreased N-acetylaspartate (NAA)+N-acetyl-aspartyl-glutamate (NAAG) and creatine (Cr)+phosphocreatine (PCr) concentrations in the left hippocampus. In the explorative analyses in the left hippocampus we identified positive associations between microglial activation and the NAA+NAAG concentration, between alcohol use and NAA+NAAG concentration, between microglial activation and the depression score and a negative relation between Cr+PCr concentration and experienced occupational disability. Duration of illness associated positively with volume bilaterally.

CONCLUSION

Compared to HCs, the decreased NAA+NAAG concentration in the left hippocampus of BD-I patients suggests a decreased neuronal integrity in this region. In addition we found a positive relation between microglial activation and neuronal integrity in vivo, corresponding to a differentiated microglial function where some microglia induce apoptosis while others stimulate neurogenesis.

Celecoxib Adjunctive Treatment to Antipsychotics in Schizophrenia: A Review of Randomized Clinical Add-On Trials

Schizophrenia is a severe, chronic and debilitating mental disorder. Past literature has reported various hypotheses about the psychopathology of schizophrenia. Recently, a growing literature has been trying to explain the role of inflammation in the etiopathogenesis of schizophrenia. In the past, numerous immune modulation and anti-inflammatory treatment options have been proposed for schizophrenia, but sometimes the results were inconsistent. Electronic search was carried out in November 2015. PubMed and Scopus databases have been used to find studies to introduce in this review. Only randomized-placebo-controlled add-on trials were taken into account. In this way, six articles were obtained for the discussion. Celecoxib showed beneficial effects mostly in early stages of schizophrenia. In chronic schizophrenia, the data are controversial, possibly in part for methodological reasons.

Risk of bipolar disorder in patients with COPD: a population-based cohort study

BAKCGROUND

Few studies have investigated the relationship between chronic obstructive pulmonary disease (COPD) and bipolar outcomes in the world. We sought to investigate the association between COPD and risk of bipolar disorder in a large national sample.

METHODS

The insured aged 15 years or more with a new primary diagnosis of COPD (ICD-9: 491, 492, 494 and 496) between 2000 and 2007 were identified from Taiwan's National Health Insurance Research Database. We included individuals with an inpatient diagnosis of COPD and/or at least 1 year of two diagnoses of COPD in outpatient services. These 35,558 cases were compared to 35,558 sex-, age-, residence- and insurance premium-matched controls. We followed both groups until the end of 2008 for incidence of bipolar disorder, defined as ICD-9 codes 296.0-296.16, 296.4-296.81 and 296.89. Competing risk-adjusted Cox regression analyses were applied with adjusting for sex, age, residence, insurance premium, prednisone use, Charlson comorbidity index, diabetes, hypertension, hyperlipidemia, cardiovascular diseases, hospital admission days, outpatients' visits and mortality.

RESULTS

Of the total 71,116 subjects, 202 were newly diagnosed with bipolar disorder during the study period. The mean follow-up time was 6.0 (SD=2.2) years. COPD, younger age, lower economic status, lower dose of prednisone use, higher hospital admission days and higher outpatient visits were independent predictors of bipolar disorder.

CONCLUSIONS

COPD was associated with increased risk of bipolar disorder independent of a number of potential confounding factors in this study.

Is it time for immunopsychiatry in psychotic disorders?

INTRODUCTION

Immune dysregulation is suggested to play an important aetiological role in schizophrenia (SZ) and bipolar disorder (BD) potentially driving neurodevelopmental pathways. Immune dysfunction may precede the onset of psychiatric disorders and parallel the development of multiaxial comorbidity, including suicidal behaviour and metabolic and autoimmune disorders. Depicting the source of the chronic low-grade inflammatory component in SZ and BD is thus a research priority. Strong environmental insults early in life, such as infections, acting on a background of genetic vulnerability, may induce potent and enduring inflammatory responses setting a state of liability to second-hit environmental encounters, namely childhood trauma, drug abuse or additional infectious exposures. The immunogenetic background of susceptibility, suggested to be not only lying within the HLA locus but also implicating inherited deficits of the innate immune system, may amplify the harmful biological effects of infections/psychosocial stress leading to the manifestation of a broad range of psychiatric symptoms.

OBJECTIVES

The present review aims to discuss the following: (i) biological arguments in favour of a chronic low-grade inflammation in SZ and BD and its potential origin in the interaction between the immunogenetic background and environmental infectious insults, and (ii) the consequences of this inflammatory dysfunction by focusing on N-methyl-D-aspartate (NMDA) receptor antibodies and activation of the family of human endogenous retroviruses (HERVs).

CONCLUSIONS

Specific therapeutic approaches targeting immune pathways may lead the way to novel personalized medical interventions, improvement of quality of life and average life expectancy of psychiatric patients, if not even prevent mood episodes and psychotic symptoms.

Biomarkers in schizophrenia: A focus on blood based diagnostics and theranostics

Identifying biomarkers that can be used as diagnostics or predictors of treatment response (theranostics) in people with schizophrenia (Sz) will be an important step towards being able to provide personalized treatment. Findings from the studies in brain tissue have not yet been translated into biomarkers that are practical in clinical use because brain biopsies are not acceptable and neuroimaging techniques are expensive and the results are inconclusive. Thus, in recent years, there has been search for blood-based biomarkers for Sz as a valid alternative. Although there are some encouraging preliminary data to support the notion of peripheral biomarkers for Sz, it must be acknowledged that Sz is a complex and heterogeneous disorder which needs to be further dissected into subtype using biological based and clinical markers. The scope of this review is to critically examine published blood-based biomarker of Sz, focusing on possible uses for diagnosis, treatment response, or their relationship with schizophrenia-associated phenotype. We sorted the studies into six categories which include: (1) brain-derived neurotrophic factor; (2) inflammation and immune function; (3) neurochemistry; (4) oxidative stress response and metabolism; (5) epigenetics and microRNA; and (6) transcriptome and proteome studies. This review also summarized the molecules which have been conclusively reported as potential blood-based biomarkers for Sz in different blood cell types. Finally, we further discusses the pitfall of current blood-based studies and suggest that a prediction model-based, Sz specific, blood oriented study design as well as standardize blood collection conditions would be useful for Sz biomarker development.

Inflammatory Cytokines and Antipsychotic-Induced Weight Gain: Review and Clinical Implications

Antipsychotic medications (APs), particularly second-generation APs, are associated with significant weight gain in schizophrenia patients. Recent evidence suggests that the immune system may contribute to antipsychotic-induced weight gain (AIWG) via AP-mediated alterations of cytokine levels. Antipsychotics with a high propensity for weight gain, such as clozapine and olanzapine, influence the expression of immune genes, and induce changes in serum cytokine levels to ultimately down-regulate neuroinflammation. Since inflammatory cytokines are normally involved in anorexigenic responses, reduced inflammation has been independently shown to mediate changes in feeding behaviours and other metabolic parameters, resulting in obesity. Genetic variation in pro-inflammatory cytokines is also associated with both general obesity and weight change during AP treatment, and thus, may be implicated in the pharmacogenetics of AIWG. At this time, preliminary data support a cytokine-mediated model of AIWG which may have clinical utility in developing more effective metabolic monitoring guidelines and prevention measures. However, further research is still needed to clearly elucidate the validity of this immune model. This article reviews the evidence implicating inflammatory cytokines in AIWG and its potential clinical relevance.

Difference in inflammatory cytokine production by mononuclear cells from obese and non-obese schizophrenic patients

OBJECTIVE

Schizophrenic patients have an increased risk for obesity compared with the general population. Evidence suggests the existence of an inflammatory process in the etiology of both obesity and schizophrenia. Our study compares in vitro secretion of inflammatory cytokines by peripheral blood mononuclear cells (PBMC) obtained from obese and non-obese schizophrenic patients.

METHOD

Mononuclear cells were isolated from 20 obese (BMI >27) and 20 non-obese (BMI <24) schizophrenic in-patients. The levels of TNF-α, IL-1β, IL-6, IL-1ra, IL-10 or IL-2 and IFN-γ in the supernatants of stimulated PBMC, as well as leptin and adiponectin serum values were evaluated.

RESULTS

Peripheral blood mononuclear cells from patients in the obese group showed a significantly increased TNF-α and IL-1β production, whereas the release of IL-1ra was decreased as compared with the non-obese group. In the obese group, the serum concentration of leptin was significantly higher and that of adiponectin was significantly lower. The results of the remaining cytokines did not differ between the two groups.

CONCLUSION

Our study indicates the existence of a difference between obese and non-obese schizophrenic subjects as for inflammatory cytokine production and serum leptin and adiponectin levels, suggesting a 'subclinical inflammatory state' in obese schizophrenic patients that may contribute to a predisposition to inflammation and infections.

The Effect of Clozapine on Hematological Indices: A 1-Year Follow-Up Study

Clozapine is the antipsychotic of choice for treatment-resistant schizophrenia and is linked to a need for mandatory hematological monitoring. Besides agranulocytosis, other hematological aberrations have resulted in premature termination in some cases. Considering clozapine's role in immunomodulation, we proceeded to investigate the impact of clozapine on the following 3 main hematological cell lines: red blood cells, platelets, white blood cells (WBCs), and its differential counts. Data were extracted from patients initiated on clozapine between January 2009 and December 2010 at a single hospital. Patients with a preclozapine complete blood count, who were receiving clozapine during the 1-year follow-up period, were included in the present investigation. Counts of red blood cells, platelets, WBC, and its differential including neutrophils, lymphocytes, monocytes, eosinophils, and basophils were extracted and trajectories plotted. One hundred one patients were included in this study and 66 remained on clozapine at the end of 1 year. There was a synchronized but transient increase in WBC, neutrophils, monocytes, eosinophils, basophils, and platelets beginning as early as the first week of clozapine treatment. There were no cases of agranulocytosis reported in this sample, and five developed neutropenia. A spike in neutrophils immediately preceded the onset of neutropenia in three of the five. The cumulative incidence rates were 48.9% for neutrophilia, 5.9% for eosinophilia, and 3% each for thrombocytosis and thrombocytopenia. Early hematological aberrations are visible across a range of cell lines, primarily of the myeloid lineage. These disturbances are transient and are probably related to clozapine's immunomodulatory properties. We do not suggest discontinuing clozapine as a consequence of the observed aberrations.

Inflammation in venous thromboembolism: Cause or consequence?

Venous thromboembolism (VTE) which includes deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) is a moderately common disease especially in elderly population with high rate of recurrence and complications. Evidence is accumulating that VTE is not restricted to coagulation system and immune system appears to be involved in formation and resolution of thrombus. The present study was aimed at reviewing current evidences on immune system abnormalities such as alterations in cytokines, chemokines and immune cells. Also, current evidences suggest that; a, inflammation in general functions as a double-edged sword, b, inflammation can be both a cause and a consequence of VTE, and c, current anti-coagulation therapies are not well-equipped with the capacity to selectively inhibit inflammatory cells and pathways. Applying such inferences for selective pharmacological targeting of immune mediators in VTE and thereby for adoption of higher effective anti-thromboinflammatory strategies, either therapeutic or prophylactic, is henceforth to be considered as the line of research for future.

Antipsychotic drug exposure and risk of pneumonia: a systematic review and meta-analysis of observational studies

PURPOSE

Pneumonia is one of the major leading causes of morbidity and mortality among persons aged 65 years or older. Recently, several studies suggested an association between antipsychotic (AP) use and risk of pneumonia in elderly patients. The aim of the present systematic review and meta-analysis of observational studies was to investigate if first-generation and second-generation AP drugs increase the risk of pneumonia in the elderly and also in the younger population, and to ascertain the risk associated with exposure to individual drugs.

METHODS

All observational cohort or case-control studies that reported data on pneumonia outcomes in individuals exposed to AP drugs as compared with individuals unexposed or with past exposure to AP drugs were included in the systematic review and meta-analysis. Study participants were of either sex and of any age with no restrictions in terms of diagnostic categories.

RESULTS

The risk of pneumonia was significantly increased by exposure to first-generation AP drugs (odds ratio (OR) 1.68, 95% confidence interval (95%CI) 1.39-2.04, I(2)  = 47%) and exposure to second-generation AP drugs (OR 1.98, 95%CI 1.67-2.35, I(2)  = 36.7%). The risk was similar among different diagnostic categories and age groups, in elderly and young-adult populations; the finding on age was corroborated by a meta-regression analysis, which did not detect any relationship between age and risk of pneumonia. Only few studies provided data on individual drugs.

CONCLUSION

Systematic review of current observational evidence suggests that exposure to first-generation and second-generation AP drugs is associated with an increased risk of pneumonia. The present systematic review expands previous knowledge by showing that the increased risk not only applies to elderly individuals but also to younger patients. The information about the risk of pneumonia for individual compounds is still very limited.

Altered IL-2, IL-6 and IL-8 serum levels in schizophrenia patients with tardive dyskinesia

Immune deregulation has been postulated to be one of the mechanisms underlying the pathogenesis of tardive dyskinesia (TD). We hypothesized that interleukins would have a link with TD in schizophrenia patients. In this study, the serum IL-2, IL-6 and IL-8 levels were examined by enzyme-linked immunosorbent assay (ELISA) in schizophrenia patients with TD (n=48) and without TD (n=45), and healthy controls (n=44). The psychopathological symptoms of schizophrenia were assessed by the Positive and Negative Syndrome Scale (PANSS). The severity of TD was evaluated using Abnormal Involuntary Movement Scale (AIMS). The results showed that serum IL-2, IL-6 and IL-8 levels were significantly different among schizophrenia patients with TD and without TD and normal controls. Moreover, IL-2 level was significantly correlated with PANSS positive subscale and general subscale in patients with TD and without TD. In addition, IL-2 level was positively correlated with AIMS score in TD patients. The results supported that immune disturbance is related to the schizophrenia patients, especially to the patients with TD and ILs might play an important role in the pathophysiology of schizophrenia patients with TD.

Abnormal immune system development and function in schizophrenia helps reconcile diverse findings and suggests new treatment and prevention strategies

Extensive research implicates disturbed immune function and development in the etiology and pathology of schizophrenia. In addition to reviewing evidence for immunological factors in schizophrenia, this paper discusses how an emerging model of atypical immune function and development helps explain a wide variety of well-established - but puzzling - findings about schizophrenia. A number of theorists have presented hypotheses that early immune system programming, disrupted by pre- and perinatal adversity, often combines with abnormal brain development to produce schizophrenia. The present paper focuses on the hypothesis that disruption of early immune system development produces a latent immune vulnerability that manifests more fully after puberty, when changes in immune function and the thymus leave individuals more susceptible to infections and immune dysfunctions that contribute to schizophrenia. Complementing neurodevelopmental models, this hypothesis integrates findings on many contributing factors to schizophrenia, including prenatal adversity, genes, climate, migration, infections, and stress, among others. It helps explain, for example, why (a) schizophrenia onset is typically delayed until years after prenatal adversity, (b) individual risk factors alone often do not lead to schizophrenia, and (c) schizophrenia prevalence rates actually tend to be higher in economically advantaged countries. Here we discuss how the hypothesis explains 10 key findings, and suggests new, potentially highly cost-effective, strategies for treatment and prevention of schizophrenia. Moreover, while most human research linking immune factors to schizophrenia has been correlational, these strategies provide ethical ways to experimentally test in humans theories about immune function and schizophrenia. This article is part of a Special Issue entitled SI: Neuroimmunology in Health And Disease.

Novel investigational drugs targeting IL-6 signaling for the treatment of depression

INTRODUCTION

Elevated levels of IL-6 have been implicated in the pathophysiology and treatment of major depressive disorder (MDD). Convergent evidence suggests that IL-6 primarily mediates proinflammatory functions via the soluble IL-6 receptor/trans-signaling, and anti-inflammatory functions via a transmembrane receptor (IL-6R). A targeted approach to selectively inhibit IL-6 trans-signaling may offer putative antidepressant effects.

AREAS COVERED

This review addresses three primary domains. The first focuses on the biological role of IL-6 within inflammation and its signal transduction pathways. The second addresses the potential contributions of IL-6 to the pathophysiology of MDD, and the mechanisms that may mediate these effects. Finally, the article outlines the therapeutic benefits of incorporating anti-inflammatory properties into the pharmacological treatment of MDD, and proposes inhibition of IL-6 signaling as a viable treatment strategy.

EXPERT OPINION

To improve drug development for the treatment of MDD, there is a critical need to identify promising targets. Target identification will require guidance from a strategic framework such as The Research Domain Criteria, and convincing evidence relating known targets to brain function under both physiological and pathological conditions. Although current evidence provides rationale for administering anti-IL-6 treatments in MDD, further studies confirming safety, target affinity and therapeutic benefits are warranted.

[Parvovirus B19 seroprevalence in a group of schizophrenic patients]

BACKGROUND

Schizophrenia is a highly disabling chronic mental illness. It is considerded as a neurodeveloppemental illness resulting from the interaction of genetic and environmental factors. Growing evidence supports the major role of prenatal infections and inflammation in the genesis of schizophrenia. The hypothesis including viral infections has been the subject of several studies and the role of parvovirus B19 (PB19) in the onset of the disease has been suggested. However, there is, up till now, no seroepidemiological evidence of his involvement.

OBJECTIVE

To determine the prevalence of parvovirus B19 (PB19) in schizophrenic patients and in control subjects and to examine clinical associations between viral prevalence, risk factors of infectious disease and clinical features.

METHOD

We carried out a case-control seroepidemiological study in the Psychiatry department of Farhat-Hached general hospital of Sousse (Tunisia). We recruited108 schizophrenic patients and 108 healthy controls free from any psychotic disorder and matched for age and sex. We collected sociodemographic data, medical history, axis I comorbid disorders and infectious risk factors. We assessed patients for psychopathology and severity of illness using respectively the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impressions (CGI). For each study participant, blood sample was collected and levels of IgG and IgM anti-PB19 were measured using the ELISA technique.

RESULTS

The prevalence of IgG antibodies to PB19 was significantly higher in schizophrenic patients than in controls (73.1% vs 60.2%; P=0.04). There were no statistical differences between the two groups regarding the prevalence of IgM antibodies to PB19. No association was found between viral prevalence and sociodemographic data, risk factors for infection or clinical characteristics. The presence of PB19 antibodies was associated with a lower score on the PANSS negative subscale (P=0.04). No other signficative association were found.

CONCLUSIONS

In our study, prevalence of IgG antibodies to PB19 was significantly higher in schizophrenic patients than in controls. This finding supports the hypothesis of the involvement of PB19 in schizophrenia. Further studies including both virological and immunological aspects are needed to better clarify the etiopathogenic mechanisms of schizophrenia which would challenge the management of this disease.

Impaired activation of the innate immune response to bacterial challenge in Tourette syndrome

OBJECTIVES

Infections resulting in immune activation have been proposed to play an etiological role in a subgroup of patients with Tourette syndrome (TS).

METHODS

In order to further characterize the interaction between pathogens and the innate immune system the toll-like receptor (TLR) 4 on CD14 + monocytes and soluble CD14 (sCD14) levels were analyzed in the serum of 33 Tourette patients and 31 healthy controls. Moreover, collected blood samples were stimulated with lipopolysaccharide (LPS) mimicking a bacterial infection. TLR4 was analysed by flow cytometry, sCD14 was analysed by enzyme-linked immunosorbent assay.

RESULTS

Patients had a lower receptor expression of TLR4 after stimulation with LPS (P = 0.045) and higher levels of sCD14 (unstimulated P = 0.014, after LPS P = 0.045). The increase in TLR4 expression after stimulation with LPS was significantly higher in the control group (P = 0.041).

CONCLUSIONS

Higher levels of sCD14, lower levels of TLR4 expression after stimulation and a diminished up-regulation of TLR4 expression after LPS stimulation in patients might represent an impaired activation of the innate immune response in TS, especially in regard to bacterial infection. The impaired response to pathogens could eventually lead to a higher susceptibility for infections. Recurring infections and a chronic inflammation could trigger and maintain the symptoms of TS.

Clozapine promotes the proliferation of granulocyte progenitors in the bone marrow leading to increased granulopoiesis and neutrophilia in rats

Clozapine is an atypical antipsychotic that is limited in its use due to the risk of idiosyncratic agranulocytosis. The bone marrow is suspected to be the site of the reaction, and indirect measurements in patients suggest that neutrophil production and maturation are altered in the marrow by clozapine. Specifically, the majority of patients have elevated neutrophil counts at the start of treatment, often paired with increased serum granulocyte-colony stimulating factor (G-CSF). Employing a rat model of clozapine treatment, we set out to determine if the neutrophilia observed at the start of treatment is characteristic of G-CSF-associated bone marrow stimulation. Female Sprague-Dawley rats were treated with 30 mg/kg/day of clozapine for 10 days, and sustained neutrophilia was evident after 1 week of treatment paired with spikes in G-CSF. Within the bone marrow, clozapine was found to induce proliferation of the granulocyte progenitor colonies as measured by a methylcellulose assay. This led to elevated granulopoiesis observed by H&E and myeloperoxidase staining of bone marrow slices. Increased release of neutrophils from the marrow to the circulation was measured through 5-bromo-2'-deoxyuridine labeling in vivo, and these neutrophils appeared to be less mature based on (a) a decrease in the nuclear lobe count and (b) increased expression of surface CD62L. Furthermore, faster transit of the neutrophils through the marrow was suggested by a shift toward elevated numbers of neutrophils in the bone marrow maturation pool and increased CD11b and CD18 staining on the less mature neutrophils residing in the marrow. Taken together, these data indicate that clozapine stimulates the bone marrow to produce more neutrophils in a manner that is characteristic of endogenous G-CSF stimulation, and it is consistent with the inflammatory response observed in patients treated with clozapine.