Serum autoantibodies against α7-nicotinic receptors in subgroups of patients with bipolar disorder or schizophrenia: clinical features and link with peripheral inflammation.

There is growing evidence that autoantibodies (AAbs) against proteins expressed in the brain are playing an important role in neurological and psychiatric disorders. Here, we explore the presence and the role of peripheral AAbs to the α7-nicotinic acetylcholine receptor (nAChR) in inflammatory subgroups of psychiatric patients with bipolar disorder (BD) or schizophrenia (SCZ) and healthy controls. We have identified a continuum of AAb levels in serum when employing a novel ELISA technique, with a significant elevation in patients compared to controls. Using unsupervised two-step clustering to stratify all the subjects according to their immuno-inflammatory background, we delineate one subgroup consisting solely of psychiatric patients with severe symptoms, high inflammatory profile, and significantly increased levels of anti-nAChR AAbs. In this context, we have used monoclonal mouse anti-human α7-nAChR antibodies (α7-nAChR-mAbs) and shown that TNF-α release was enhanced upon LPS stimulation in macrophages pre-incubated with α7-nAChR-mAbs compared to the use of an isotype control. These findings provide a basis for further study of circulating nicotinic AAbs, and the inflammatory profile observed in patients with major mood and psychotic disorders.

A human leukocyte antigen imputation study uncovers possible genetic interplay between gut inflammatory processes and autism spectrum disorders.

Autism spectrum disorders (ASD) are neurodevelopmental conditions that are for subsets of individuals, underpinned by dysregulated immune processes, including inflammation, autoimmunity, and dysbiosis. Consequently, the major histocompatibility complex (MHC)-hosted human leukocyte antigen (HLA) has been implicated in ASD risk, although seldom investigated. By utilizing a GWAS performed by the EU-AIMS consortium (LEAP cohort), we compared HLA and MHC genetic variants, single nucleotide polymorphisms (SNP), and haplotypes in ASD individuals, versus typically developing controls. We uncovered six SNPs, namely rs9268528, rs9268542, rs9268556, rs14004, rs9268557, and rs8084 that crossed the Bonferroni threshold, which form the underpinnings of 3 independent genetic pathways/blocks that differentially associate with ASD. Block 1 (rs9268528-G, rs9268542-G, rs9268556-C, and rs14004-A) afforded protection against ASD development, whilst the two remaining blocks, namely rs9268557-T, and rs8084-A, associated with heightened risk. rs8084 and rs14004 mapped to the HLA-DRA gene, whilst the four other SNPs located in the BTNL2 locus. Different combinations amongst BTNL2 SNPs and HLA amino acid variants or classical alleles were found either to afford protection from or contribute to ASD risk, indicating a genetic interplay between BTNL2 and HLA. Interestingly, the detected variants had transcriptional and/or quantitative traits loci implications. As BTNL2 modulates gastrointestinal homeostasis and the identified HLA alleles regulate the gastrointestinal tract in celiac disease, it is proposed that the data on ASD risk may be linked to genetically regulated gut inflammatory processes. These findings might have implications for the prevention and treatment of ASD, via the targeting of gut-related processes.

Patients with psychosis spectrum disorders hospitalized during the COVID-19 pandemic unravel overlooked SARS-CoV-2 past infection clustering with HERV-W ENV expression and chronic inflammation.

Epidemiology has repeatedly associated certain infections with a risk of further developing psychiatric diseases. Such infections can activate retro-transposable genetic elements (HERV) known to trigger immune receptors and impair synaptic plasticity of neuroreceptors. Since the HERV-W ENV protein was recently shown to co-cluster with pro-inflammatory cytokines in a subgroup of patients with schizophrenia or bipolar disorder, we questioned the influence of the COVID-19 pandemic on patients with psychosis spectrum disorders (PSD). Present results revealed that (i) SARS-CoV-2 serology shows high prevalence and titers of antibodies in PSD, (ii) HERV-W ENV is detected in seropositive individuals only and (iii) SARS-CoV-2 and HERV-W ENV positivity co-clustered with high serum levels of pro-inflammatory cytokines in psychotic patients. These results thus suggest that SARS-CoV-2 infection in many patients with psychotic disorders now admitted in the psychiatry department did not cause severe COVID-19. They also confirm the previously reported association of elevated serum pro-inflammatory cytokines and HERV-W ENV in a subgroup of psychotic patients. In the context of the COVID-19 pandemic, this cluster is only found in SARS-CoV-2 seropositive PSD cases, suggesting a dominant influence of this virus on HERV-W ENV and cytokine expression, and/or patients' greater susceptibility to SARS-CoV-2 infection. Further investigation on an interplay between this viral infection and the clinical evolution of such PSD patients is needed. However, this repeatedly defined subgroup of psychotic patients with a pro-inflammatory phenotype and HERV expression calls for a differential therapeutic approach in psychoses, therefore for further precision medicine development.

Immune cell subsets in patients with bipolar disorder or schizophrenia with history of childhood maltreatment.

A history of Childhood Maltreatment (CM) has been repeatedly associated with an increased risk of developing bipolar disorders (BD) or schizophrenia (SZ). The impact of severe stress induced by CM has been proposed to be mediated by elevated inflammation reflected by dysregulated inflammatory processes. Little is known about the potential impact of CM on lymphocyte subpopulations or the role of pre-existing infections on CM physiological consequences. This study therefore explored the role of CM and past infection exposure impact on lymphocyte subpopulations to give an indication of their relevance as stressors in the pathoetiology of major mood and psychotic disorders. 118 adult patients with SZ, and 152 with BD were included in the analysis. CM history was assessed by the Childhood Trauma Questionnaire (CTQ), with current and past psychiatric symptomatology also evaluated. Circulating immune cell subsets were analyzed using flow cytometry-based analysis. Past exposure to common infectious stigma including toxoplasma, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) were measured by solid phase-enzyme microplate and ELISA immunoassays. The relationship between CM, biological phenotypes (including immune cell subsets distribution and past infectious status) and clinical phenotypes were analyzed using univariate and multivariate analyses. BD patients with, versus without, CM had higher levels of CD3+CD8+ cytotoxic T cells and CMV antibodies along with decreased levels of CD45RA+CCR7+CD8+ naïve CD8+ T cells, and a more severe clinical profile. CMV antibody levels were inversely associated with the CD3 + CD8 + lymphocyte subset level. SZ patients with, versus without, CM, showed lower levels of CD14 + monocytes and no specific clinical characteristics. The accumulation of different types of maltreatment associated with increased body mass index and CMV autoantibodies as well as decreased levels of CD14 + monocytes. In both BD and SZ, further analysis according to the type and the number of CM subtypes showed association with specific changes in lymphocyte cell subsets, clinical profile, and infectious stigma. Adults with BD or SZ exposed to CM exhibit specific immune cell subset profiles, clinical features, and stigma of past infections. In BD, our data indicate an interplay between CM and CMV infections, which may possibly contribute to premature aging and cellular senescence, both of which have previously been shown to associate with mood disorders. Longitudinal studies of CM-exposed patients are required to clarify the interactions of CM and viral infections, including as to the pathophysiological processes driving patient symptomatology.

Cognitive performance at first episode of psychosis and the relationship with future treatment resistance: Evidence from an international prospective cohort study.

BACKGROUND: Antipsychotic treatment resistance affects up to a third of individuals with schizophrenia, with recent research finding systematic biological differences between antipsychotic resistant and responsive patients. Our aim was to determine whether cognitive impairment at first episode significantly differs between future antipsychotic responders and resistant cases. METHODS: Analysis of data from seven international cohorts of first-episode psychosis (FEP) with cognitive data at baseline (N = 683) and follow-up data on antipsychotic treatment response: 605 treatment responsive and 78 treatment resistant cases. Cognitive measures were grouped into seven cognitive domains based on the pre-existing literature. We ran multiple imputation for missing data and used logistic regression to test for associations between cognitive performance at FEP and treatment resistant status at follow-up. RESULTS: On average patients who were future classified as treatment resistant reported poorer performance across most cognitive domains at baseline. Univariate logistic regressions showed that antipsychotic treatment resistance cases had significantly poorer IQ/general cognitive functioning at FEP (OR = 0.70, p = .003). These findings remained significant after adjusting for additional variables in multivariable analyses (OR = 0.76, p = .049). CONCLUSIONS: Although replication in larger studies is required, it appears that deficits in IQ/general cognitive functioning at first episode are associated with future treatment resistance. Cognitive variables may be able to provide further insight into neurodevelopmental factors associated with treatment resistance or act as early predictors of treatment resistance, which could allow prompt identification of refractory illness and timely interventions.

Clinical and pharmacological correlates of caffeine consumption in subjects with schizophrenia - Data from the FACE-SZ cohort.

Caffeine is the most consumed psychoactive substance worldwide. Previous studies suggested higher caffeine consumption in subjects with schizophrenia spectrum disorders (SSD) as well as associations with symptoms, medication and medication side-effects. In a large and well-characterized sample of SSD subjects we explored the association between caffeine consumption and clinical (psychosis related, severity, general health) as well as pharmacological (antipsychotic treatment, sedation potential) variables. Eight hundred four subjects with data on their caffeine (coffee and tea) consumption successively recruited were included in this study. After controlling for potential confounders (demographic variables, smoking) only the negative dimension of psychosis was associated with the amount of caffeine ingested. Less severe negative symptoms were associated with higher caffeine consumption. The effect size of this association was small (partial correlation coefficient = -0.12) but significant.

Kynurenine pathway abnormalities are state-specific but not diagnosis-specific in schizophrenia and bipolar disorder.

Schizophrenia (SCZ) and bipolar disorder (BD) are associated with immunological dysfunctions that have been hypothesized to lead to clinical symptomatology in particular through kynurenine pathway abnormalities. The aim of this study was thus to investigate the impact of serum kynurenine metabolite levels on diagnosis, clinical state, symptom severity and clinical course in a large French transdiagnostic cohort of SCZ and BD patients. Four patient groups (total n = 507) were included in a cross-sectional observational study: 1) hospitalized acute bipolar patients (n = 205); 2) stable bipolar outpatients (n = 116); 3) hospitalized acute schizophrenia patients (n = 111) and 4) stable schizophrenia outpatients (n = 75), in addition to healthy controls (HC) (n = 185). The quantitative determination of serum kynurenine metabolites was performed using liquid chromatography-tandem mass spectrometry. Kynurenine levels were lower in all patients combined compared to HC while ANCOVA analyses did not reveal inter-diagnostic difference between SCZ and BD. Interestingly, hospitalized patients of both diagnostic groups combined displayed significantly lower kynurenine levels than stabilized outpatients. Psychotic symptoms were associated with lower quinaldic acid (F = 9.18, p=<.001), which is KAT-driven, whereas a longer duration of illness contributed to abnormalities in tryptophan (F = 5.41, p = .023), kynurenine (F = 16.93, p=<.001), xanthurenic acid (F = 9.34, p = .002), quinolinic acid (F = 9.18, p = .003) and picolinic acid (F = 4.15, p = .043), metabolized through the KMO-branch. These data confirm illness state rather than diagnosis to drive KP alterations in SCZ and BD. Lower levels of KP metabolites can thus be viewed as a transdiagnostic feature of SCZ and BD, independently associated with acute symptomatology and a longer duration of illness. Quinaldic acid has seldomly been investigated by previous studies and appears an important state marker in SCZ and BD. As serum samples are used in this study, it is not possible to extrapolate these findings to the brain.

Clinical predictors of antipsychotic treatment resistance: Development and internal validation of a prognostic prediction model by the STRATA-G consortium.

INTRODUCTION: Our aim was to, firstly, identify characteristics at first-episode of psychosis that are associated with later antipsychotic treatment resistance (TR) and, secondly, to develop a parsimonious prediction model for TR. METHODS: We combined data from ten prospective, first-episode psychosis cohorts from across Europe and categorised patients as TR or non-treatment resistant (NTR) after a mean follow up of 4.18 years (s.d. = 3.20) for secondary data analysis. We identified a list of potential predictors from clinical and demographic data recorded at first-episode. These potential predictors were entered in two models: a multivariable logistic regression to identify which were independently associated with TR and a penalised logistic regression, which performed variable selection, to produce a parsimonious prediction model. This model was internally validated using a 5-fold, 50-repeat cross-validation optimism-correction. RESULTS: Our sample consisted of N = 2216 participants of which 385 (17 %) developed TR. Younger age of psychosis onset and fewer years in education were independently associated with increased odds of developing TR. The prediction model selected 7 out of 17 variables that, when combined, could quantify the risk of being TR better than chance. These included age of onset, years in education, gender, BMI, relationship status, alcohol use, and positive symptoms. The optimism-corrected area under the curve was 0.59 (accuracy = 64 %, sensitivity = 48 %, and specificity = 76 %). IMPLICATIONS: Our findings show that treatment resistance can be predicted, at first-episode of psychosis. Pending a model update and external validation, we demonstrate the potential value of prediction models for TR.

PM2.5 and PM10 air pollution peaks are associated with emergency department visits for psychotic and mood disorders.

Particulate matters with a diameter of less than 10 µm (PM10) or less than 2.5 µm (PM2.5) are major air pollutants. Their relationship to psychiatric disorders has not yet been extensively studied. We aimed to explore the relationship between PM10 and PM2.5 air pollution peaks and the daily number of emergency visits for psychotic and mood disorders. Clinical data were collected from the Emergency Department of a Paris suburb (Créteil, France) from 2008 to 2018. Air pollution data were measured by the Paris region air quality network (Airparif) and collected from public databases. Pollution peak periods were defined as days for which the daily mean level of PM was above nationally predefined warning thresholds (20 µg/m3 for PM2.5, and 50 µg/m3 for PM10), and the 6 following days. Multivariable analyses compared the number of daily visits for psychotic and mood (unipolar and bipolar) disorders according to pollution peak, using negative binomial regression. After adjustment on meteorological variables (temperature, humidity, amount of sunshine in minutes), the daily number of emergency visits for psychotic disorders was significantly higher during PM2.5 and PM10 air pollution peak periods; while the number of visits for unipolar depressive disorders was higher only during PM10 peak periods (ß = 0.059, p-value = 0.034). There were no significant differences between peak and non-peak periods for bipolar disorders. Differences in the effects of PM air pollution on psychotic and mood disorders should be analyzed in further studies.

Possible Effect of the use of Mesenchymal Stromal Cells in the Treatment of Autism Spectrum Disorders: A Review.

Autism spectrum disorder (ASD) represents a set of heterogeneous neurodevelopmental conditions defined by impaired social interactions and repetitive behaviors. The number of reported cases has increased over the past decades, and ASD is now a major public health burden. So far, only treatments to alleviate symptoms are available, with still unmet need for an effective disease treatment to reduce ASD core symptoms. Genetic predisposition alone can only explain a small fraction of the ASD cases. It has been reported that environmental factors interacting with specific inter-individual genetic background may induce immune dysfunctions and contribute to the incidence of ASD. Such dysfunctions can be observed at the central level, with increased microglial cells and activation in ASD brains or in the peripheral blood, as reflected by high circulating levels of pro-inflammatory cytokines, abnormal activation of T-cell subsets, presence of auto-antibodies and of dysregulated microbiota profiles. Altogether, the dysfunction of immune processes may result from immunogenetically-determined inefficient immune responses against a given challenge followed by chronic inflammation and autoimmunity. In this context, immunomodulatory therapies might offer a valid therapeutic option. Mesenchymal stromal cells (MSC) immunoregulatory and immunosuppressive properties constitute a strong rationale for their use to improve ASD clinical symptoms. In vitro studies and pre-clinical models have shown that MSC can induce synapse formation and enhance synaptic function with consequent improvement of ASD-like symptoms in mice. In addition, two preliminary human trials based on the infusion of cord blood-derived MSC showed the safety and tolerability of the procedure in children with ASD and reported promising clinical improvement of core symptoms. We review herein the immune dysfunctions associated with ASD provided, the rationale for using MSC to treat patients with ASD and summarize the current available studies addressing this subject.

HLA-E circulating and genetic determinants in schizophrenia and bipolar disorder.

Schizophrenia (SZ) and bipolar disorders (BD) are severe mental illnesses that lack reliable biomarkers to guide diagnosis and management. As immune dysregulation is associated with these disorders, we utilized the immunoregulatory functions of the natural killer cell inhibitory HLA-E locus to investigate the relationships between HLA-E genetic and expression diversities with SZ and BD risk and severity. Four hundred and forty-four patients meeting DSM-IV criteria for SZ (N = 161) or BD (N = 283) were compared to 160 heathy controls (HC). Circulating levels of the soluble isoform of HLA-E molecules (sHLA-E) were measured and HLA-E*01:01 and HLA-E*01:03 variants genotyped in the whole sample. sHLA-E circulating levels were significantly higher in both SZ and in BD patients compared to HC (pc < 0.0001 and pc = 0.0007 for SZ and BD, respectively). High sHLA-E levels were also observed in stable SZ patients and in acute BD patients experiencing depressive episodes when comparisons were made between the acute and stable subgroups of each disorder. sHLA-E levels linearly increased along HLA-E genotypes (p = 0.0036). In conclusion, HLA-E variants and level may have utility as diagnostic biomarkers of SZ and BD. The possible roles of HLA diversity in SZ and BD etiology and pathophysiology are discussed.

Low peripheral mitochondrial DNA copy number during manic episodes of bipolar disorders is associated with disease severity and inflammation.

Mitochondria (Mt) are intra-cellular components essential for cellular energy processes whose dysfunction may induce premature cellular senescence and/or inflammation, both observed in bipolar disorders (BD). We investigated mitochondrial DNA copy number (mtDNAcn) levels in patients with BD being in manic, depressive or euthymic phase and in healthy controls (HC) both characterized for the levels of blood-based inflammatory markers and stigma of pathogens. 312 patients with BD were compared to 180 HC. mtDNAcn were measured using a digital droplet PCR. Serum levels of 14 inflammatory molecules and 3 anti-infectious IgG stigma were respectively evaluated by electro-chemiluminescence, ELISA and dedicated immunoassays. The statistical analyses were performed using Spearman's correlation, Wilcoxon signed-rank and Kruskal-Wallis rank sum tests. P-values were adjusted for multiple testing with Benjamini-Hochberg method. We found low levels of mtDNAcn in BD patients as compared to HC (P = 0.008) especially during manic episodes (P = 0.0002). We also observed that low levels of mtDNAcn are negatively correlated with mood and psychotic scales (PANSS, YMRS and CGI) (adjusted P (Adj P) = 0.02, 0.003 and 0.05 respectively) and positively with the GAF severity scale (Adj P = 0.002). They were also correlated with high levels of both intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 (Adj P = 0.003 and 0.001) along with a trend toward increased IL-2, IL-10 and B2M circulating levels (Adj P = 0.05). Here, we report correlations between marker of mitochondria functioning and both clinical scales and inflammatory markers in BD patients experiencing manic episodes. If replicated, these finding might allow to predict transition between disease phases and to design accurate therapeutic options.

Fecal Supernatant from Adult with Autism Spectrum Disorder Alters Digestive Functions, Intestinal Epithelial Barrier, and Enteric Nervous System.

Autism Spectrum Disorders (ASDs) are neurodevelopmental disorders defined by impaired social interactions and communication with repetitive behaviors, activities, or interests. Gastrointestinal (GI) disturbances and gut microbiota dysbiosis are frequently associated with ASD in childhood. However, it is not known whether microbiota dysbiosis in ASD patients also occurs in adulthood. Further, the consequences of altered gut microbiota on digestive functions and the enteric nervous system (ENS) remain unexplored. Therefore, we studied, in mice, the ability offecal supernatant (FS) from adult ASD patients to induce GI dysfunctions and ENS remodeling. First, the analyses of the fecal microbiota composition in adult ASD patients indicated a reduced α-diversity and increased abundance of three bacterial 16S rRNA gene amplicon sequence variants compared to healthy controls (HC). The transfer of FS from ASD patients (FS-ASD) to mice decreased colonic barrier permeability by 29% and 58% compared to FS-HC for paracellular and transcellular permeability, respectively. These effects are associated with the reduced expression of the tight junction proteins JAM-A, ZO-2, cingulin, and proinflammatory cytokines TNFα and IL1ß. In addition, the expression of glial and neuronal molecules was reduced by FS-ASD as compared to FS-HC in particular for those involved in neuronal connectivity (ßIII-tubulin and synapsin decreased by 31% and 67%, respectively). Our data suggest that changes in microbiota composition in ASD may contribute to GI alterations, and in part, via ENS remodeling.

Identification of inflammatory subgroups of schizophrenia and bipolar disorder patients with HERV-W ENV antigenemia by unsupervised cluster analysis.

Human endogenous retroviruses (HERVs) are remnants of infections that took place several million years ago and represent around 8% of the human genome. Despite evidence implicating increased expression of HERV type W envelope (HERV-W ENV) in schizophrenia and bipolar disorder, it remains unknown whether such expression is associated with distinct clinical or biological characteristics and symptoms. Accordingly, we performed unsupervised two-step clustering of a multivariate data set that included HERV-W ENV protein antigenemia, serum cytokine levels, childhood trauma scores, and clinical data of cohorts of patients with schizophrenia (n = 29), bipolar disorder (n = 43) and healthy controls (n = 32). We found that subsets of patients with schizophrenia (~41%) and bipolar disorder (~28%) show positive antigenemia for HERV-W ENV protein, whereas the large majority (96%) of controls was found to be negative for ENV protein. Unsupervised cluster analysis identified the presence of two main clusters of patients, which were best predicted by the presence or absence of HERV-W ENV protein. HERV-W expression was associated with increased serum levels of inflammatory cytokines and higher childhood maltreatment scores. Furthermore, patients with schizophrenia who were positive for HERV-W ENV protein showed more manic symptoms and higher daily chlorpromazine (CPZ) equivalents, whereas HERV-W ENV positive patients with bipolar disorder were found to have an earlier disease onset than those who were negative for HERV-W ENV protein. Taken together, our study suggest that HERV-W ENV protein antigenemia and cytokines can be used to stratify patients with major mood and psychotic disorders into subgroups with differing inflammatory and clinical profiles.

No alteration of leukocyte telomere length in first episode psychosis.

Both shorter telomeres and schizophrenia have been associated with a decrease in life expectancy. Furthermore, several studies found a shorter telomere length (TL) in schizophrenia. Understanding whether or not telomere shortening is directly related to pathophysiology of schizophrenia or is a consequence of a cumulative exposure to chronic stress is of major importance. Comparing the TL of subjects at the very beginning of the disease (FEP) and control subjects could help to decide between these two hypotheses. The aim of the present study was to compare TL between FEP subjects (N=91) and controls (N=137). After accounting for multiple potential confounders, no significant association was observed between FEP and TL. Our result is consistent with the hypothesis that psycho-social stress / adversities and stressful situations in people with schizophrenia affect TL rather than that telomere erosion contributes to the development of this disorder.

The Independent Effects of Psychosocial Stressors on Subclinical Psychosis: Findings From the Multinational EU-GEI Study.

The influence of psychosocial stressors on psychosis risk has usually been studied in isolation and after the onset of the disorder, potentially ignoring important confounding relationships or the fact that some stressors that may be the consequence of the disorder rather than preexisting. The study of subclinical psychosis could help to address some of these issues. In this study, we investigated whether there was (i) an association between dimensions of subclinical psychosis and several psychosocial stressors including: childhood trauma, self-reported discrimination experiences, low social capital, and stressful life experiences, and (ii) any evidence of environment-environment (ExE) interactions between these factors. Data were drawn from the EUGEI study, in which healthy controls (N = 1497) and siblings of subjects with a psychotic disorder (N = 265) were included in six countries. The association between psychosocial stressors and subclinical psychosis dimensions (positive, negative and depressive dimension as measured by the Community Assessment of Psychic Experiences (CAPE) scale) and possible ExE interactions were assessed using linear regression models. After adjusting for sex, age, ethnicity, country, and control/sibling status, childhood trauma (ß for positive dimension: 0.13, negative: 0.49, depressive: 0.26) and stressful life events (positive: 0.08, negative: 0.16, depressive: 0.17) were associated with the three dimensions. Lower social capital was associated with the negative and depression dimensions (negative: 0.26, depressive: 0.13), and self-reported discrimination experiences with the positive dimension (0.06). Our findings are in favor of independent, cumulative and non-specific influences of social adversities in subclinical psychosis in non-clinical populations, without arguments for E × E interactions.

Characteristics associated with the risk of psychosis among immigrants and their descendants in France.

OBJECTIVE: To explore the sociodemographic characteristics that might explain the increased incidence of psychosis among immigrants and their descendants in France. METHODS: Data were collected for all subjects with first contact for psychosis aged between 18 and 64 years, in two catchment areas in the Paris region. Incidence rates (IR) and incidence rate ratios (IRR) were adjusted for gender and age. RESULTS: During 805,396 persons-year at risk, we identified 321 cases of first-episode psychosis, of which 129 were immigrants and 78 descendants of immigrants. We found that the geographic origin was associated with the risk of psychosis although generation has little impact. Sub-Saharan African immigrants and their descendants showed the highest risk (IRR = 3.1 and IRR = 2.9, respectively). We observed that living in deprived areas increased the incidence of psychosis (IRR = 1.3, 95CI%: 1.0-1.6), particularly among immigrants (IRR = 1.6; 95% CI: 1.1-2.5). Finally, our study showed that subjects having unstable housing (a proxy for "hard to count population") could inflate the incidence rates among immigrants. CONCLUSION: The current study shows that the increased risk of psychosis in groups with an immigration background in France is associated with their origin and highlights the importance of socioeconomic factors in modulating this risk.

Natural killer cells in first-episode psychosis: an innate immune signature?

Accumulating evidence majorly implicates immune dysfunction in the etiology of psychotic disorders. In particular, altered numbers and functions of natural killer (NK) cells have been described in psychosis, but interpretation has often been confounded by a number of biases, including treatment. Eighty-one first-episode psychosis (FEP) patients who subsequently received a diagnosis of either schizophrenia (SZ; n = 30) or bipolar disorder (BP; n = 31) over a five-year follow-up period were investigated for their NK cell phenotype and compared to 61 healthy controls (HCs). We found a similar proportion of CD3-CD56+ NK cells in FEP patients and HCs. The frequency of NK cells expressing the late cell activation marker HLA-DR was significantly increased in FEP patients compared to HCs, especially in patients with BP (p < 0.0001) and, to a lesser degree, in patients with SZ (p = 0.0128). Interestingly, the expression of the activating NKG2C receptor, known to be associated with infections, was higher in patients with SZ and BP than in HCs (p < 0.0001) and correlated with HLA-DR expression, altogether defining adaptive NK cells. In terms of NK cell function, we observed a suppressed capacity of SZ-derived NK cells to mount cytotoxic responses in the presence of target cells, while NK cells from patients with BP show an inability to produce IFN-γ, a cytokine pivotal to NK function. This study strongly suggests major dysfunction of NK cells in FEP with functioning impairment correlated with psychotic, manic, and depressive symptoms in subsequently diagnosed patients with SZ and BP.