Immune and neuroimmune alterations in mood disorders and schizophrenia

Exploring peripheral biomarkers of response to simvastatin supplementation in schizophrenia

Schizophrenia is one of the most debilitating mental disorders, and its diagnosis and treatment present significant challenges. Several clinical trials have previously evaluated the effectiveness of simvastatin, a lipid-lowering medication, as a novel add-on treatment for schizophrenia. However, treatment effects varied highly between patients and over time. In the present study, we aimed to identify biomarkers of response to simvastatin in recent-onset schizophrenia patients. To this end, we profiled relevant immune and metabolic markers in patient blood samples collected in a previous clinical trial (ClinicalTrials.gov: NCT01999309) before simvastatin add-on treatment was initiated. Analysed sample types included serum, plasma, resting-state peripheral blood mononuclear cells (PBMCs), as well as PBMC samples treated ex vivo with immune stimulants and simvastatin. Associations between the blood readouts and clinical endpoints were evaluated using multivariable linear regression. This revealed that changes in insulin receptor (IR) levels induced in B-cells by ex vivo simvastatin treatment inversely correlated with in vivo effects on cognition at the primary endpoint of 12 months, as measured using the Brief Assessment of Cognition in Schizophrenia scale total score (standardised β ± SE = -0.75 ± 0.16, P = 2.2 × 10-4, Q = 0.029; n = 21 patients). This correlation was not observed in the placebo group (β ± SE = 0.62 ± 0.39, P = 0.17, Q = 0.49; n = 14 patients). The candidate biomarker explained 53.4 % of the variation in cognitive outcomes after simvastatin supplementation. Despite the small sample size, these findings suggest a possible interaction between the insulin signalling pathway and cognitive effects during simvastatin therapy. They also point to opportunities for personalized schizophrenia treatment through patient stratification.

Analysis of complete blood count and derived inflammatory indicators for bipolar disorder patients with different states

Purposes

This study aimed to analyze the predictive ability of the complete blood count and derived inflammatory indicators for BD patients with different states to identify potential biomarkers.

Methods

We collected the data of BD in-patients from January 2021 to March 2023. The complete blood count and derived inflammatory indicators were computed by univariate analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis.

Results

In terms of BD patients, the levels of MON (p<0.0001), hs-CRP (p = 0.018), and NLR (p = 0.002) were independent risk factors in logistic regression analysis, as well as the cut-off values were 0.405 109/L, 2.600 mg/L, and 2.321, respectively. Regarding BD-M patients, the levels of MON (p<0.0001), hs-CRP (p = 0.012), and NLR (p = 0.002) were predictors in logistic regression analysis, and the cut-off values were, respectively, 0.505 109/L, 2.600 mg/L, and 2.620. Additionally, the levels of NLR (p = 0.006) and MHR (p<0.0001) were important indicators for BD-D and the cut-off values were 1.735 and 0.487, respectively. Furthermore, our findings showed that the level of MON (p = 0.001) was related to BD-mixed and the cut-off value was 0.340 109/L. Notably, MON+hs-CRP + NLR, MON+hs-CRP + NLR, and NLR + MHR had the highest diagnostic accuracy to predict BD, BD-M, and BD-D patients, respectively.

Conclusion

Our findings showed that distinct inflammatory indicators were closely associated with BD and its different states. Additionally, we also identified their cut-off values and optimal combined predictive indicators in different states of BD, helping us improve diagnostic accuracy and better assess them to manage early targeted interventions.

Inflammation Markers Among Schizophrenia Patients Who Use Cannabis

OBJECTIVES

The mechanism of inflammation of the immune system, for example, such circulatory markers as the neutrophil-to-lymphocyte ratio (NLR) and mean platelet volume (MPV), has been shown in many studies to be associated with schizophrenia. In addition, it has been shown that the cannabidiol component reduces the activation of the acquired immune system. This study examined the differences in the levels of NLR and MPV among schizophrenia patients with cannabis use versus those without.

METHODS

In 2019 to 2020, a retrospective cross-sectional study was conducted based on digital medical records. Demographic, clinical, and complete blood cell count data were collected from records of rehospitalization of active psychotic schizophrenia inpatients. Data on NLR, MPV values, and demographic and clinical characteristics were compared between the groups and according to the degree of prevalence of cannabis use.

RESULTS

No differences were found in the NLR and MPV values between the groups.

CONCLUSION

The results were contrary to our expectations. These results may be explained by the presentation of a "pseudo-balanced" picture created when multiple processes affect inflammatory indices.

Diagnostic model development for schizophrenia based on peripheral blood mononuclear cell subtype-specific expression of metabolic markers

A significant proportion of the personal and economic burden of schizophrenia can be attributed to the late diagnosis or misdiagnosis of the disorder. A novel, objective diagnostic approaches could facilitate the early detection and treatment of schizophrenia and improve patient outcomes. In the present study, we aimed to identify robust schizophrenia-specific blood biomarkers, with the goal of developing an accurate diagnostic model. The levels of selected serum and peripheral blood mononuclear cell (PBMC) markers relevant to metabolic and immune function were measured in healthy controls (n = 26) and recent-onset schizophrenia patients (n = 36) using multiplexed immunoassays and flow cytometry. Analysis of covariance revealed significant upregulation of insulin receptor (IR) and fatty acid translocase (CD36) levels in T helper cells (F = 10.75, P = 0.002, Q = 0.024 and F = 21.58, P = 2.8 × 10^-5, Q = 0.0004, respectively), as well as downregulation of glucose transporter 1 (GLUT1) expression in monocytes (F = 21.46, P = 2.9 × 10^-5, Q = 0.0004). The most robust predictors, monocyte GLUT1 and T helper cell CD36, were used to develop a diagnostic model, which showed a leave-one-out cross-validated area under the receiver operating characteristic curve (AUC) of 0.78 (95% CI: 0.66-0.92). The diagnostic model was validated in two independent datasets. The model was able to distinguish first-onset, drug-naïve schizophrenia patients (n = 34) from healthy controls (n = 39) with an AUC of 0.75 (95% CI: 0.64-0.86), and also differentiated schizophrenia patients (n = 22) from patients with other neuropsychiatric conditions, including bipolar disorder, major depressive disorder and autism spectrum disorder (n = 68), with an AUC of 0.83 (95% CI: 0.75-0.92). These findings indicate that PBMC-derived biomarkers have the potential to support an accurate and objective differential diagnosis of schizophrenia.

Neutrophil-to-Lymphocyte, Monocyte-to-Lymphocyte, Platelet-to-Lymphocyte Ratio and Systemic Immune-Inflammatory Index in Different States of Bipolar Disorder

The neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammatory (SII) index, which provide a simple, rapid, inexpensive method to measure the level of inflammation, have been examined as potential inflammatory biomarkers of bipolar disorder (BD) in several studies. We conducted a case-control study recruiting 180 BD patients and 407 healthy controls. BD patients who met the inclusion criteria and were hospitalized due to BD at the psychiatry clinic of the University General Hospital of Larisa, Greece, until September 2021 were included in the study. Among them, 111 patients experienced a manic episode and 69 patients experienced a depressive episode. Data including a complete blood count were retrieved from their first admission to the hospital. Bipolar patients had a higher NLR, MLR and SII index compared to healthy controls when they were experiencing a manic episode (p < 0.001) and a depressive episode (p < 0.001). MLR was increased with large effect size only in patients expressing manic episodes. Neutrophils and NLR had the highest area under the curve with a cutoff of 4.38 and 2.15 in the ROC curve, respectively. Gender-related differences were mainly observed in the SII index, with males who were expressing manic episodes and females expressing depressive episodes having an increased index compared to healthy controls. The NLR, MLR and SII index were significantly higher in patients with BD than in healthy controls, which implies a higher grade of inflammation in BD patients.

Comparison of Hematological Parameters Between First-Episode Schizophrenia and Anti-NMDAR Encephalitis

Background: First-episode schizophrenia (FES) and anti-NMDAR encephalitis are different disorders with similar psychiatric symptoms, and both diseases are associated with the inflammatory system. In this study, we compared hematological parameters and inflammation ratios in anti-NMDAR encephalitis, FES, and healthy control.

Methods: We enrolled 106 patients (53 FES patients and 53 anti-NMDAR encephalitis patients) and 59 healthy controls. The values of the neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), monocyte–lymphocyte ratio (MLR), and systemic immune-inflammation index (SII) were used to evaluate inflammation. Other parameters such as the white blood cell (WBC), platelet (PLT), uric acid (UA), total bilirubin (TBIL), total bile acid (TBA), and serum albumin counts were also used to compare inflammation ratios between these two diseases.

Results: SII, NLR, PLR, MLR, and serum albumin levels were statistically significantly different between these three groups (p < 0.05). The values of SII, NLR, PLR, and MLR were significantly higher in the anti-NMDAR encephalitis group than those in the FES group (p < 0.05), and the values in both diseases were more increased than those in HC (p < 0.05). The serum albumin level was significantly lower in anti-NMDAR encephalitis than in FES (p < 0.05). WBC, neutrophil, lymphocyte, and monocyte counts showed significantly higher levels in the anti-NMDAR encephalitis group and FES group separately (p < 0.05). Other parameters like TBA, TBIL, and UA showed no difference between groups.

Conclusion: In summary, this is a relatively new study that is innovative by comparing some inflammation markers of peripheral blood in two diseases with clinically psychotic symptoms. These two diseases are related to the inflammatory system, proving that NMDAR dysfunction is related to psychotic symptoms. Besides, NLR, PLR, MLR, and serum albumin can be used as biomarkers to distinguish the two diseases. The serum albumin level in patients with anti-NMDAR encephalitis was lower than that in patients with schizophrenia.

Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) Levels in Adolescent with Bipolar Disorder and Their Relationship with Metabolic Parameters

Peroxisome proliferator-activated receptor gamma (PPARγ) is one of the immune and metabolic regulatory agents. This study examined the serum PPARγ levels and metabolic syndrome (MetS) parameters in pediatric bipolar disorder (PBD) adolescents and compared them with healthy subjects. Serum PPARγ levels, fasting blood glucose (FBG), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and fasting insulin levels of 39 PBD-type I (age range: 14-18) and 36 age- and sex-matched healthy control subjects were compared. The anthropometric measurements were also analyzed, including body weight, height, body mass index (BMI), waist circumference (WC), and blood pressure measurements. The PPARγ levels were significantly lower, and the MetS prevalence was significantly higher in the PBD group than in the control group. The mean BMI, WC, serum TG, and FBG values of the PBD group were statistically higher than the healthy control group. There was no significant relationship between the PPARγ levels and metabolic parameters except fasting glucose. Lower PPARγ activity and higher MetS prevalence in PBD indicate dysregulation of immune and metabolic regulatory parameters. These results may shed light on developing new PBD medications.

Chronic circadian phase advance in male mice induces depressive-like responses and suppresses neuroimmune activation

Altered working and sleeping schedules during the COVID-19 pandemic likely impact our circadian systems. At the molecular level, clock genes form feedback inhibition loops that control 24-hr oscillations throughout the body. Importantly, core clock genes also regulate microglia, the brain resident immune cell, suggesting circadian regulation of neuroimmune function. To assess whether circadian disruption induces neuroimmune and associated behavioral changes, we mimicked chronic jetlag with a chronic phase advance (CPA) model. 32 adult male C57BL/6J mice underwent 6-hr light phase advance shifts every 3 light/dark cycles (CPA) 14 times or were maintained in standard light/dark cycles (control). CPA mice showed higher behavioral despair but not anhedonia in forced swim and sucrose preferences tests, respectively. Changes in behavior were accompanied by altered hippocampal circadian genes in CPA mice. Further, CPA suppressed expression of brain-derived neurotrophic factor (BDNF) and pro-inflammatory cytokine interleukin-1 beta in the hippocampus. Plasma corticosterone concentrations were elevated by CPA, suggesting that CPA may suppress neuroimmune pathways via glucocorticoids. These results demonstrate that chronic circadian disruption alters mood and neuroimmune function, which may have implications for shift working populations such as frontline health workers.

Immunological Interfaces: The COVID-19 Pandemic and Depression

Since the start of the spread of the coronavirus disease 2019 (COVID-19) pandemic, an international effort has sought to better characterize associated extra-pulmonary health sequelae. The acute and or chronic detrimental impact of SARS-CoV-2 infection on mental health, especially depression, is increasingly described. Simultaneously the pandemic has influenced depressive symptomatology by modifying economic, social and political structures, in addition to affecting daily routines. In both cases, associated immunological perturbations favoring a pro-inflammatory state could underlie an increased risk for depressive symptomatology. A resultant elevation in global depressive burden could further tax mental health care infrastructure and contribute to a range of worse health outcomes including diminished quality of life. This suggests a critical and time-sensitive need to better understand immune interfaces between depression and COVID-19.

Changes in peripheral blood compounds following psychopharmacological treatment in drug-naïve first-episode patients with either schizophrenia or major depressive disorder: a meta-analysis

BACKGROUND

This meta-analysis on peripheral blood compounds in drug-naïve first-episode patients with either schizophrenia or major depressive disorder (MDD) examined which compounds change following psychopharmacological treatment.

METHODS

The Embase, PubMed and PsycINFO databases were systematically searched for longitudinal studies reporting measurements of blood compounds in drug-naïve first-episode schizophrenia or MDD.

RESULTS

For this random-effects meta-analysis, we retrieved a total of 31 studies comprising 1818 schizophrenia patients, and 14 studies comprising 469 MDD patients. Brain-derived neurotrophic factor (BDNF) increased following treatment in schizophrenia (Hedges' g (g): 0.55; 95% confidence interval (CI) 0.39-0.70; p < 0.001) and MDD (g: 0.51; CI 0.06-0.96; p = 0.027). Interleukin (IL)-6 levels decreased in schizophrenia (g: -0.48; CI -0.85 to -0.11; p = 0.011), and for MDD a trend of decreased IL-6 levels was observed (g: -0.39; CI -0.87 to 0.09; p = 0.115). Tumor necrosis factor alpha (TNFα) also decreased in schizophrenia (g: -0.34; CI -0.68 to -0.01; p = 0.047) and in MDD (g: -1.02; CI -1.79 to -0.25; p = 0.009). Fasting glucose levels increased only in schizophrenia (g: 0.26; CI 0.07-0.44; p = 0.007), but not in MDD. No changes were found for C-reactive protein, IL-1β, IL-2 and IL-4.

CONCLUSIONS

Psychopharmacological treatment has modulating effects on BDNF and TNFα in drug-naïve first-episode patients with either schizophrenia or MDD. These findings support efforts for further research into transdiagnostic preventive strategies and augmentation therapy for those with immune dysfunctions.

Cyclooxygenase Inhibition Safety and Efficacy in Inflammation-Based Psychiatric Disorders

According to the World Health Organization, the major psychiatric and neurodevelopmental disorders include major depression, bipolar disorder, schizophrenia, and autism spectrum disorder. The potential role of inflammation in the onset and progression of these disorders is increasingly being studied. The use of non-steroidal anti-inflammatory drugs (NSAIDs), well-known cyclooxygenase (COX) inhibitors, combined with first-choice specific drugs have been long investigated. The adjunctive administration of COX inhibitors to classic clinical treatments seems to improve the prognosis of people who suffer from psychiatric disorders. In this review, a broad overview of the use of COX inhibitors in the treatment of inflammation-based psychiatric disorders is provided. For this purpose, a critical analysis of the use of COX inhibitors in the last ten years of clinical trials of the major psychiatric disorders was carried out.

Thiol/Disulfide Homeostasis in Bipolar and Unipolar Depression

Objective

Bipolar disorder and unipolar depressive disorder are complex phenotypes. There appear to be phenotypical, mechanistic, and therapeutic differences between bipolar depression (BD) and unipolar depression (UD). There is a need for understanding the underlying biological variation between these clinical entities. The role of oxidative processes underlying bipolar disorder and depression has been demonstrated. Thiol-disulfide homeostasis (TDH) is a recent oxidative stress marker. In this study, we aimed to inspect patients with bipolar depression and unipolar depression in terms of thiol-disulfide balance and to compare them with healthy controls.

Methods

Patients admitted to the outpatient clinic of Ankara Numune Training and Research Hospital and diagnosed either as a depressive episode with bipolar disorder (n = 37) or unipolar depression (n = 24) according to DSM-5 criteria, along with healthy controls (HC) (n = 50), were included in the study. Native thiol, total thiol, and disulfide levels were compared across the groups.

Results

In comparison to HC, both BD and UD groups had higher disulfide levels, disulfide/native thiol ratio, and disulfide/total thiol ratio. No significant differences between BD and UD were detected in terms of disulfide level, disulfide/native thiol ratio, and disulfide/total thiol ratio.

Conclusion

Increased levels of disulfide, native thiol, and disulfide/total thiol ratios compared to healthy controls in both UD and BD groups may be indicative of the presence of oxidative damage in these two clinical conditions. To clarify the role of oxidative stress in the pathophysiology of depressive disorders and investigate TDH, longitudinal studies in patients with medication-free UD and BD are required.

Altered peripheral blood compounds in drug-naïve first-episode patients with either schizophrenia or major depressive disorder: a meta-analysis

IMPORTANCE

Schizophrenia and major depressive disorder (MDD) are associated with increased risks of immunologic disease and metabolic syndrome. It is unclear to what extent growth, immune or glucose dysregulations are similarly present in these disorders without the influence of treatment or chronicity.

OBJECTIVE

To conduct a meta-analysis investigating whether there are altered peripheral growth, immune or glucose metabolism compounds in drug-naïve first-episode patients with schizophrenia or MDD compared with controls.

DATA SOURCES AND STUDY SELECTION

Case-control studies reporting compound measures in drug-naïve first-episode patients with schizophrenia or MDD compared with controls in the Embase, PubMed and PsycINFO databases.

DATA EXTRACTION AND SYNTHESIS

Two independent authors extracted data for a random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Peripheral growth, immune or glucose metabolism compounds in schizophrenia or MDD compared with controls. Standardized mean differences were quantified with Hedges' g (g).

RESULTS

74 studies were retrieved comprising 3453 drug-naïve first-episode schizophrenia patients and 4152 controls, and 29 studies were retrieved comprising 1095 drug-naïve first-episode MDD patients and 1399 controls. Growth factors: brain-derived neurotrophic factor (BDNF) (g = -0.77, P < .001) and nerve growth factor (NGF) (g = -2.51, P = .03) were decreased in schizophrenia. For MDD, we observed a trend toward decreased BDNF (g = -0.47, P = .19) and NGF (g = -0.33, P = .08) levels, and elevated vascular endothelial growth factor levels (g = 0.40, P = .03). Immune factors: interleukin (IL)-6 (g = 0.95, P < .001), IL-8 (g = 0.59, P = .001) and tumor necrosis factor alpha (TNFα) (g = 0.48, P = .002) were elevated in schizophrenia. For C-reactive protein (CRP) (g = 0.57, P = .09), IL-4 (g = 0.44, P = .10) and interferon gamma (g = 0.33, P = .11) we observed a trend toward elevated levels in schizophrenia. In MDD, IL-6 (g = 0.62, P = .007), TNFα (g = 1.21, P < .001), CRP (g = 0.53, P < .001), IL-1β (g = 1.52, P = .009) and IL-2 (g = 4.41, P = .04) were elevated, whereas IL-8 (g = -0.84, P = .01) was decreased. The fasting glucose metabolism factors glucose (g = 0.24, P = .003) and insulin (g = 0.38, P = .003) were elevated in schizophrenia.

CONCLUSIONS AND RELEVANCE

Both schizophrenia and MDD show alterations in growth and immune factors from disease onset. An altered glucose metabolism seems to be present from onset in schizophrenia. These findings support efforts for further research into transdiagnostic preventive strategies and augmentation therapy for those with immune or metabolic dysfunctions.

Current challenges and possible future developments in personalized psychiatry with an emphasis on psychotic disorders

A personalized medicine approach seems to be particularly applicable to psychiatry. Indeed, considering mental illness as deregulation, unique to each patient, of molecular pathways, governing the development and functioning of the brain, seems to be the most justified way to understand and treat disorders of this medical category. In order to extract correct information about the implicated molecular pathways, data can be drawn from sampling phenotypic and genetic biomarkers and then analyzed by a machine learning algorithm. This review describes current difficulties in the field of personalized psychiatry and gives several examples of possibly actionable biomarkers of psychotic and other psychiatric disorders, including several examples of genetic studies relevant to personalized psychiatry. Most of these biomarkers are not yet ready to be introduced in clinical practice. In a next step, a perspective on the path personalized psychiatry may take in the future is given, paying particular attention to machine learning algorithms that can be used with the goal of handling multidimensional datasets.

Inflammatory, cardio-metabolic and diabetic profiling of chronic schizophrenia

Background

There is a growing interest in low-grade inflammatory and metabolic alterations in patients with chronic schizophrenia (SCH).

Methods

Inflammatory (tumor-necrosis factor-α [TNF-α], interferon-γ [IFN-γ], interleukins [IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10], monocyte chemo-attractant protein-1 [MCP-1]) and growth factors (vascular endothelial growth factor [VEGF], epidermal growth factor [EGF]) were measured in blood serum samples of 105 SCH patients and 148 control subjects (CS). Simultaneously the clinical biomarkers (C-reactive protein [CRP], triglycerides [TG], low-density lipoprotein [LDL-c] and high-density lipoprotein [HDL-c] cholesterol, glycated hemoglobin [HbA1c]) were measured, and body mass index (BMI) was calculated for patients.

Results

Several cyto-/chemokines (IFN-γ, MCP-1, IL-2, IL-6, IL-8 and IL-10) were significantly (P < 0.0000001) elevated in SCH patients compared to CS. Odds ratios, obtained from logistic regression analyses, were significantly elevated for IL-2, IL-6, IL-10, INF-γ, and decreased for TNF-α in SCH group. Among the patients, higher IL-2, IL-6, INF-γ and lower MCP-1 levels as well as male gender were together significant (P < 0.000001) predictors of higher HbA1c levels, and TG/HDL-c parameter was associated with ratios of INF-γ/IL-10 (P = 0.004), and INF-γ/IL-4 (P = 0.049), HbA1c (P = 0.005), INF-γ (P = 0.009), as well as LDL-c (P = 0.02) levels.

Conclusions

IL-2, IL-6, IL-10 and IFN-γ were the most significant SCH-related markers among the measured cytokines in our patient group. Furthermore, significant associations between pro-/anti-inflammatory imbalance and HbA1c as well as cardio-metabolic risk marker (TG/HDL-c) were observed, indicating higher risks of diabetes and cardiovascular diseases among SCH patients.

The association between antibodies to neurotropic pathogens and bipolar disorder : A study in the Dutch Bipolar (DB) Cohort and meta-analysis

Exposure to neurotropic pathogens has been hypothesized to be a risk factor for the development of bipolar disorder (BD). However, evidence so far is inconsistent. We, therefore, analyzed the seroprevalence and titer levels of IgG antibodies against several herpesviruses and Toxoplasma gondii (T. gondii) in plasma of 760 patients with a bipolar disorder, 144 first-degree matched relatives and 132 controls of the Dutch Bipolar (DB) Cohort using ELISA. In addition, we performed a literature-based meta-analysis on the seroprevalence of IgG antibodies against these pathogens (n = 14). Our results in the DB Cohort and subsequent meta-analysis (n = 2364 BD patients, n = 5101 controls) show no association between exposure to herpesviruses and bipolar disorder (HSV-1 [adjusted OR 0.842, 95% CI 0.567-1.230], HSV-2 [adjusted OR 0.877, 95% CI 0.437-1.761], CMV [adjusted OR 0.884 95% CI 0.603-1.295], EBV [adjusted OR 0.968 95% CI 0.658-1.423]). In the DB Cohort, we did not find an association between bipolar disorder and T. gondii titer or seroprevalence either [adjusted OR 1.018, 95% CI 0.672-1.542]. The overall OR was not significant for T. gondii [OR: 1.4, 95% CI 0.95-1.90, p = 0.09), but subgroup analyses in age groups below 40 years showed a significantly increased seroprevalence of T. gondii IgGs in BD [OR: 1.8 (95% CI 1.10-2.89, p = 0.021]. Our meta-analysis indicates that T. gondii exposure may be a risk factor for BD in certain subpopulations.

Cross-sectional study of neutrophil-lymphocyte, platelet-lymphocyte and monocyte-lymphocyte ratios in mood disorders

OBJECTIVE

Neutrophil-lymphocyte, monocyte-lymphocyte and platelet-lymphocyte ratio are inexpensive and reproducible biomarkers of inflammation found to be elevated in mood disorders. This study aimed to compare inflammatory ratios between bipolar disorder and major depressive disorder and between bipolar disorder manic episodes and bipolar disorder depressive episodes.

METHOD

We included 142 Caucasian patients (major depressive disorder: n = 36; bipolar disorder manic episode: n = 66; bipolar disorder depressive episode: n = 40). We measured white blood cells, neutrophils, lymphocytes, monocytes, platelets, glucose, and total cholesterol. Neutrophil-lymphocyte ratio, monocyte-lymphocyte ratio, and platelet-lymphocyte ratio were calculated.

RESULTS

Neutrophil-lymphocyte ratio and monocyte-lymphocyte ratio were significantly higher in bipolar disorder manic episodes when compared to bipolar disorder depressive episodes and major depressive disorder episodes after adjustment for age, sex, body mass index, and smoking.

CONCLUSION

To our knowledge, our study is the first one to compare inflammatory ratios between different bipolar disorder phases and major depressive disorder episodes. In accord with previous studies on other inflammatory mediators, we found higher neutrophil-lymphocyte and monocyte-lymphocyte ratios in bipolar manic episodes, suggesting that inflammatory changes occur especially during acute episodes of mania.

Neutrophil-to-lymphocyte ratio in schizophrenia: A systematic review and meta-analysis

BACKGROUND

The immune system appears to be dysregulated in schizophrenia (SZ). The potential prognostic or diagnostic value of neutrophil-to-lymphocyte ratio (NLR), an inexpensive proxy marker for a wide spectrum of conditions, has not been established in SZ. We seek to investigate a) whether NLR is increased in SZ patients, b) if this difference in more prominent in relapsed SZ or first-episode psychosis.

METHODS

A structured algorithm was applied in MEDLINE (1946-2018), PsychInfo, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL) (1999-2018), PSYNDEX (1984-2017) and Clinicaltrials.gov (2008-2018) databases.

RESULTS

Through the database search, 1023 articles were screened. Ten studies (804 SZ patients, 671 controls) were included in the meta-analysis. In SZ patients, the NLR was increased by 0.65 (95% CI: 0.54, 0.86, p < 10^-5). This difference was significant in both acute relapse and first-episode psychosis subgroups. Studies of moderate and high quality also showed a significant NLR increase in SZ patients (I² = 0%). Meta-regression analysis showed that the polymorphonuclear count and antipsychotic use may confound the result. In leave-one-out meta-analysis, no study altered the significance of the result when omitted.

CONCLUSIONS

NLR in SZ patients is increased, both in chronic disease and in first-episode psychosis. Baseline characteristics, such as polymorphonuclear count and antipsychotic use, may affect its accuracy. The application of this marker in clinical practice requires the description of its normal values in the general population, its potential change after antipsychotic administration and its correlation with disease activity. A large-scale, prospective study design would resolve these issues.

Association between schizophrenia and an autoimmune bullous skin disease-pemphigus: a population-based large-scale study

AIMS

Immunological hypotheses have become increasingly prominent suggesting that autoimmunity may be involved in the pathogenesis of schizophrenia. Schizophrenia was found to be associated with a wide range of autoimmune diseases. However, the association between pemphigus and schizophrenia has not been established yet. We aimed to estimate the association between pemphigus and schizophrenia using a large-scale real-life computerised database.

METHODS

This study was conducted as a cross-sectional study utilising the database of Clalit Health Services. The proportion of schizophrenia was compared between patients diagnosed with pemphigus and age-, gender- and ethnicity-matched control subjects. Univariate analysis was performed using χ2 and Student's t-test and a multivariate analysis was performed using a logistic regression model.

RESULTS

A total of 1985 pemphigus patients and 9874 controls were included in the study. The prevalence of schizophrenia was greater in patients with pemphigus as compared to the control group (2.0% v. 1.3%, respectively; p = 0.019). In a multivariate analysis, pemphigus was significantly associated with schizophrenia (OR, 1.5; 95% CI, 1.1-2.2). The association was more prominent among females, patients older than 60 years, and Jews.

CONCLUSIONS

Pemphigus is significantly associated with schizophrenia. Physicians treating patients with pemphigus should be aware of this possible association. Patients with pemphigus should be carefully assessed for comorbid schizophrenia and be treated appropriately.

Genetic and environmental influences on circulating NK and T cells and their relation to bipolar disorder

BACKGROUND

In previous studies we found mild deficiencies of circulating T cells in patients with bipolar disorder (BD) and children at risk for BD, correlating to a higher inflammatory state. The genetic and environmental influences on these T cell deficiencies in association with BD development are unknown.

OBJECTIVES

The aim is to quantify genetic and environmental factors that contribute to the association between the liability to develop BD and T cell deficiencies.

METHODS

Participants of a Dutch bipolar twin study (11 monozygotic BD twin pairs, 15 dizygotic BD twin pairs, 15 monozygotic and 12 dizygotic healthy twin pairs) were included. A detailed FACS analysis of frozen stored leukocytes was carried out to determine the percentages of T cells and various other leukocyte and lymphocyte subsets. A bivariate liability threshold twin model was used to determine genetic and environmental (common and unique) influences on the correlation between BD and the various subsets.

RESULTS

Lower percentages of T cells and higher percentages of NK cells were associated with the familial liability to develop BD. Neither genetic nor shared or unique environmental factors could explain the associations. Lithium usage explained part of the association for T cells, smoking in part that for NK cells.

CONCLUSIONS

Our results confirm that BD is the result of a complex interaction between various genetic and environmental risk factors, in which T and NK cells act as important intermediate immune players.

Low-Grade Inflammation as a Predictor of Antidepressant and Anti-Inflammatory Therapy Response in MDD Patients: A Systematic Review of the Literature in Combination With an Analysis of Experimental Data Collected in the EU-MOODINFLAME Consortium

Low-grade inflammation plays a role not only in the pathogenesis of major depressive disorder (MDD) but probably also in the poor responsiveness to regular antidepressants. There are also indications that anti-inflammatory agents improve the outcomes of antidepressants. Aim: To study whether the presence of low-grade inflammation predicts the outcome of antidepressants, anti-inflammatory agents, or combinations thereof. Methods: We carried out a systematic review of the literature on the prediction capability of the serum levels of inflammatory compounds and/or the inflammatory state of circulating leukocytes for the outcome of antidepressant/anti-inflammatory treatment in MDD. We compared outcomes of the review with original data (collected in two limited trials carried out in the EU project MOODINFLAME) on the prediction capability of the inflammatory state of monocytes (as measured by inflammatory gene expression) for the outcome of venlafaxine, imipramine, or sertraline treatment, the latter with and without celecoxib added. Results: Collectively, the literature and original data showed that: 1) raised serum levels of pro-inflammatory compounds (in particular of CRP/IL-6) characterize an inflammatory form of MDD with poor responsiveness to predominately serotonergic agents, but a better responsiveness to antidepressant regimens with a) (add-on) noradrenergic, dopaminergic, or glutamatergic action or b) (add-on) anti-inflammatory agents such as infliximab, minocycline, or eicosapentaenoic acid, showing-next to anti-inflammatory-dopaminergic or lipid corrective action; 2) these successful anti-inflammatory (add-on) agents, when used in patients with low serum levels of CRP/IL-6, decreased response rates in comparison to placebo. Add-on aspirin, in contrast, improved responsiveness in such "non-inflammatory" patients; 3) patients with increased inflammatory gene expression in circulating leukocytes had a poor responsiveness to serotonergic/noradrenergic agents. Conclusions: The presence of inflammation in patients with MDD heralds a poor outcome of first-line antidepressant therapies. Immediate step-ups to dopaminergic or glutamatergic regimens or to (add-on) anti-inflammatory agents are most likely indicated. However, at present, insufficient data exist to design protocols with reliable inflammation parameter cutoff points to guide such therapies, the more since detrimental outcomes are possible of anti-inflammatory agents in "non-inflamed" patients.

Innate immunity in the postmortem brain of depressed and suicide subjects: Role of Toll-like receptors

Abnormalities of Toll-like receptors (TLRs) have been implicated in the pathophysiology of depression and suicide. Interactions of TLRs with pathogen-associated molecular patterns (PAMP) and damage-associated molecular patterns (DAMP) initiate signaling through myeloid differentiation primary response-88 (MyD88) and produce cytokines through the activation of the transcription factor nuclear factor kappa beta (NF-kB). We have earlier shown an increase in the protein and mRNA expression of TLR3 and TLR4 in the prefrontal cortex (PFC) of depressed suicide (DS) subjects compared with normal control (NC) subjects. To examine if other TLRs are altered in postmortem brain, we have now determined the protein and mRNA expression of other TLRs (TLR1, TLR2, TLR5, TLR6, TLR7, TLR8, TLR9 and TLR10) in the PFC of DS, depressed non-suicide (DNS), non-depressed suicide (NDS) and NC subjects. We determined the protein expression by Western blot and mRNA expression levels by real-time PCR (qPCR) in the PFC of 24 NC, 24 DS, 12 DNS and 11 NDS subjects. Combined with our previous study of TLR3 and TLR4, we found that the protein expression of TLR2, TLR3, TLR4, TLR6 and TLR10, and mRNA expression of TLR2 and TLR3 was significantly increased in the DS group compared with NC group. This study demonstrated that certain specific TLRs are altered in DS subjects, and hence those TLRs may be appropriate targets for the development of therapeutic agents for the treatment of suicidal behavior.

Early Senescence and Leukocyte Telomere Shortening in SCHIZOPHRENIA: A Role for Cytomegalovirus Infection?

Schizophrenia is a severe, chronic mental disorder characterized by delusions and hallucinations. Several evidences support the link of schizophrenia with accelerated telomeres shortening and accelerated aging. Thus, schizophrenia patients show higher mortality compared to age-matched healthy donors. The etiology of schizophrenia is multifactorial, involving genetic and environmental factors. Telomere erosion has been shown to be accelerated by different factors including environmental factors such as cigarette smoking and chronic alcohol consumption or by psychosocial stress such as childhood maltreatment. In humans, telomere studies have mainly relied on measurements of leukocyte telomere length and it is generally accepted that individuals with short leukocyte telomere length are considered biologically older than those with longer ones. A dysregulation of both innate and adaptive immune systems has been described in schizophrenia patients and other mental diseases supporting the contribution of the immune system to disease symptoms. Thus, it has been suggested that abnormal immune activation with high pro-inflammatory cytokine production in response to still undefined environmental agents such as herpesviruses infections can be involved in the pathogenesis and pathophysiology of schizophrenia. It has been proposed that chronic inflammation and oxidative stress are involved in the course of schizophrenia illness, early onset of cardiovascular disease, accelerated aging, and premature mortality in schizophrenia. Prenatal or neonatal exposures to neurotropic pathogens such as Cytomegalovirus or Toxoplasma gondii have been proposed as environmental risk factors for schizophrenia in individuals with a risk genetic background. Thus, pro-inflammatory cytokines and microglia activation, together with genetic vulnerability, are considered etiological factors for schizophrenia, and support that inflammation status is involved in the course of illness in schizophrenia.

Social cognition in the course of psychosis and its correlation with biomarkers in a male cohort

INTRODUCTION

Patients diagnosed with schizophrenia display deficits in Theory of Mind (ToM) and Emotion Perception (EP) even before the appearance of full-blown symptomatology.

METHODS

We evaluated ToM and EP in a male cohort consisting of 25 First Episode Psychosis (FEP) and 16 relapsed schizophrenic patients (CHRON) compared to 12 subjects in Ultra-high Risk (UHR) and 23 healthy controls (CTR). Furthermore, we measured the levels of Cortisol, Insulin like Growth Factor (IGF-1), TNF-a, TNF-b and several interleukins as potential biomarkers.

RESULTS

Deficits in EP and ToM were found in FEP, CHRON patients and UHR subjects compared to CTR. The impairments in these two domains seem to follow different patterns in the course of psychosis. EP was more impaired in subjects with a longer history of symptomatology whereas there was no statistically significant difference regarding ToM. On the other hand IL-4 was the only biomarker correlated to ToM and EP scores in two different samples of our study.

CONCLUSION

Social Cognition (SC) domains are impaired in patients with psychosis as well as in UHR subjects compared to healthy controls. There are differences in the progress of ToM and EP deficits in the course of psychosis. Interleukins as IL-4 could correlate to SC.

Immune dysregulation in offspring of a bipolar parent. Altered serum levels of immune growth factors at adolescent age

Immune dysregulation plays a role in the vulnerability for mood disorders. Immune growth factors, such as Stem Cell Factor (SCF), Insulin-like Growth Factor-Binding Protein-2 (IGF-BP2), Epidermal Growth Factor (EGF), IL-7 and sCD25 have repeatedly been reported altered in patients with mood disorders. The aim of this study was to investigate levels of these factors in serum of adolescent bipolar offspring, who have a heightened risk for mood disorder development and to also analyze the data combined with previously published data. Growth factors were assessed by CBA/ELISA in adolescent bipolar offspring (n=96, mean age=16years) and in age- and gender-matched healthy controls (n=50). EGF belonged to a mutually correlating cluster of mainly neurotrophic compounds including S100B and BDNF, which were in general decreased in serum. IL-7, SCF, IGF-BP2 and sCD25, belonged to a different mutually correlating cluster of immune growth factors, which were in general increased: IGF-BP2 significantly in serum of offspring without a mood disorder, IL-7 and SCF in serum of offspring who had experienced a mood episode. This pattern of de- and increases was not different between bipolar offspring that developed or did not develop a mood disorder over time, apart from the IGF-BP2 level, which was near significantly higher in offspring later developing a mood disorder. Correlations with the previously published immune-cellular abnormalities were not found. In conclusion non-affected adolescents at familial mood disorder development risk were characterized by a distinct pattern of a series of compounds operating in a network of hematopoiesis, neurogenesis and inflammation.

Iloperidone in the treatment of schizophrenia: an evidence-based review of its place in therapy

Introduction

Schizophrenia is a chronic and debilitating mental disorder that affects the patient’s and their family’s quality of life, as well as financial costs and health care settings. Despite the variety of available antipsychotics, optimal treatment outcomes are not always achieved. Novel drugs, such as iloperidone, can provide more effective, tolerable and safer strategies.

Aim

To review the evidence for the clinical impact of iloperidone on the treatment of patients with schizophrenia.

Evidence review

Clinical trials, observational studies and meta-analyses reached a common consensus that iloperidone is as effective as haloperidol, risperidone and ziprasidone in reducing schizophrenia symptoms. Similar amounts of adverse events and discontinuations were observed with iloperidone compared to placebo and active treatments. Common adverse events are mild and include dizziness, hypotension, dry mouth and weight gain. Iloperidone can induce extension of QTc interval, and clinicians should be aware of its contraindications. In long-term trials, iloperidone also showed promising safety and tolerability profiles. The low propensity to cause akathisia, extrapyramidal symptoms (EPS), increased prolactin levels or changes to metabolic laboratory parameters support its use in practice. Results showed that iloperidone prevents relapse in stabilized patients, with a time to relapse superior to placebo and similar to haloperidol. Patients using a prior antipsychotic (eg, risperidone and aripiprazole) can easily switch to iloperidone with no serious impact on safety or efficacy. However, the acquisition costs of iloperidone may hamper its use. Further evidence comparing iloperidone with other antipsychotics, and pharmacoeconomic studies would be welcome.

Place in therapy

Considering just the clinical profile of iloperidone, it represents a promising drug for treating schizophrenia, particularly in patients who are intolerant to previous antipsychotics, as well as being suitable as first-line therapy. Cost-effectiveness comparisons are needed to justify its use in clinical practice.

Transcriptome sequencing of the choroid plexus in schizophrenia

The choroid plexus (CP) has a key role in maintaining brain homeostasis by producing cerebrospinal fluid (CSF), by mediating transport of nutrients and removing metabolic products from the central nervous system and by responding to peripheral inflammatory signals. Although abnormal markers of immune response and inflammation are apparent in individuals with schizophrenia, the CP of these individuals has not been characterized. We therefore sequenced mRNA from the CP from two independent collections of individuals with schizophrenia and unaffected controls. Genes related to immune function and inflammation were upregulated in both collections. In addition, a co-expression module related to immune/inflammation response that was generated by combining mRNA-Seq data from both collections was significantly associated with disease status. The immune/inflammation-related co-expression module was positively correlated with levels of C-reactive protein (CRP), cortisol and several immune modulator proteins in the serum of the same individuals and was also positively correlated with CRP, cortisol and pro-inflammatory cytokines in the frontal cortex of the same individuals. In addition, we found a substantial number of nodes (genes) that were common to our schizophrenia-associated immune/inflammation module from the pooled data and a module we generated from lippopolysaccharides-treated mouse model data. These results suggest that the CP of individuals with schizophrenia are responding to signals from the periphery by upregulating immune/inflammation-related genes to protect the brain and maintain the homeostasis but nevertheless fails to completely prevent immune/inflammation related changes in the brain.

Autoimmune diseases, gastrointestinal disorders and the microbiome in schizophrenia: more than a gut feeling

Autoimmunity, gastrointestinal (GI) disorders and schizophrenia have been associated with one another for a long time. This paper reviews these connections and provides a context by which multiple risk factors for schizophrenia may be related. Epidemiological studies strongly link schizophrenia with autoimmune disorders including enteropathic celiac disease. Exposure to wheat gluten and bovine milk casein also contribute to non-celiac food sensitivities in susceptible individuals. Co-morbid GI inflammation accompanies humoral immunity to food antigens, occurs early during the course of schizophrenia and appears to be independent from antipsychotic-generated motility effects. This inflammation impacts endothelial barrier permeability and can precipitate translocation of gut bacteria into systemic circulation. Infection by the neurotropic gut pathogen, Toxoplasma gondii, will elicit an inflammatory GI environment. Such processes trigger innate immunity, including activation of complement C1q, which also functions at synapses in the brain. The emerging field of microbiome research lies at the center of these interactions with evidence that the abundance and diversity of resident gut microbiota contribute to digestion, inflammation, gut permeability and behavior. Dietary modifications of core bacterial compositions may explain inefficient gluten digestion and how immigrant status in certain situations is a risk factor for schizophrenia. Gut microbiome research in schizophrenia is in its infancy, but data in related fields suggest disease-associated altered phylogenetic compositions. In summary, this review surveys associative and experimental data linking autoimmunity, GI activity and schizophrenia, and proposes that understanding of disrupted biological pathways outside of the brain can lend valuable information regarding pathogeneses of complex, polygenic brain disorders.

Mast cell activation disease and the modern epidemic of chronic inflammatory disease

A large and growing portion of the human population, especially in developed countries, suffers 1 or more chronic, often quite burdensome ailments which either are overtly inflammatory in nature or are suspected to be of inflammatory origin, but for which investigations to date have failed to identify specific causes, let alone unifying mechanisms underlying the multiple such ailments that often afflict such patients. Relatively recently described as a non-neoplastic cousin of the rare hematologic disease mastocytosis, mast cell (MC) activation syndrome-suspected to be of greatly heterogeneous, complex acquired clonality in many cases-is a potential underlying/unifying explanation for a diverse assortment of inflammatory ailments. A brief review of MC biology and how aberrant primary MC activation might lead to such a vast range of illness is presented.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls

BACKGROUND

Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder.

METHODS

For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups.

RESULTS

Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings.

CONCLUSIONS

We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients.

Role of Immune and Autoimmune Dysfunction in Schizophrenia

In this chapter, we review data in support of the concept that immune system dysregulation is the most plausible explanation that reconciles gene by environmental interactions in schizophrenia. Early investigations of this topic demonstrated aspects of aberrant activation of humoral immunity, including autoimmunity, associated with schizophrenia, whereas current research efforts have expanded this theme to include elements of innate immunity. Advances in our understanding of inflammation and molecules of both the adaptive and innate immune system and their functional roles in standard brain physiology provide an important context by which schizophrenia might arise as the result of the coupling of immune and neurodevelopmental dysregulation.

Molecular substrates of schizophrenia: homeostatic signaling to connectivity

Schizophrenia (SZ) is a devastating psychiatric condition affecting numerous brain systems. Recent studies have identified genetic factors that confer an increased risk of SZ and participate in the disease etiopathogenesis. In parallel to such bottom-up approaches, other studies have extensively reported biological changes in patients by brain imaging, neurochemical and pharmacological approaches. This review highlights the molecular substrates identified through studies with SZ patients, namely those using top-down approaches, while also referring to the fruitful outcomes of recent genetic studies. We have subclassified the molecular substrates by system, focusing on elements of neurotransmission, targets in white matter-associated connectivity, immune/inflammatory and oxidative stress-related substrates, and molecules in endocrine and metabolic cascades. We further touch on cross-talk among these systems and comment on the utility of animal models in charting the developmental progression and interaction of these substrates. Based on this comprehensive information, we propose a framework for SZ research based on the hypothesis of an imbalance in homeostatic signaling from immune/inflammatory, oxidative stress, endocrine and metabolic cascades that, at least in part, underlies deficits in neural connectivity relevant to SZ. Thus, this review aims to provide information that is translationally useful and complementary to pathogenic hypotheses that have emerged from genetic studies. Based on such advances in SZ research, it is highly expected that we will discover biomarkers that may help in the early intervention, diagnosis or treatment of SZ.

Circulating anti-brain autoantibodies in schizophrenia and mood disorders

In recent years, an inflammatory autoimmune process, autoantibodies mediated, has been porposed as having a role in the development of different psychiatric disorders. The aim of this study was to assay organ-specific and non organ-specific circulating autoantibodies in schizophrenia, mood disorders and healthy controls; among organ-specific autoantibodies we focused on different fluorescence patterns of anti-brain autoantibodies against rat and monkey's sections of hippocampus, hypothalamus and cerebellum. Serum samples from 50 acutelly ill patients (30 schizophrenia and 20 mood disorders) and from 20 healthy controls were collected. Autoantibodies were assayed by indirect immunofluorescence, enzyme linked immunosorbent assay and chemiluminescence immunoassay. We found a significant difference for circulating autoantibodies to hypothalamus, hippocampus and cerebellum and for anti-nuclear autoantibodies in both schizophrenia and mood disorders when compared to the control group. Referring to the two groups of patients only, circulating antibodies anti-hypothalamus were found significant higher in mood disorders rather than in schizophrenia, with specific regard to nuclear and cytoplasmic staining of the neurons. These data suggest an aspecific diffuse brain involvement of anti-brain autoantibodies in acute phases of schizophrenia and mood disorders. The greater involvement of the hypothalamus in mood disorders highlights the close relationship between autoimmunity, hypothalamic-pituitary-adrenal axis and affective disorders.

Antipsychotic treatment reduces psychotic symptoms and markers of low-grade inflammation in first episode psychosis patients, but increases their body mass index

OBJECTIVE

The main goal of the present study was to analyze levels of cytokines of the interleukin family (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8 and IL-10), interferon-gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP1), tumor necrosis factor-alpha (TNF-α), and vascular endothelial and endothelial growth factors (VEGF and EGF), in the blood samples of first-episode psychosis (FEP) patients before and seven months after the start of antipsychotic medication use.

METHOD

38 anti-psychotic medication-naïve FEP patients and 37 healthy controls (HC) were recruited. Biochip array technology was used to measure cytokines and growth factors.

RESULTS

The comparison of these markers in FEP patients and HC revealed significantly higher levels of EGF, IL-4 and IL-6 and significantly lower level of IL-1β in FEP patients before the antipsychotic treatment. Multiple regression analysis demonstrated significant correlations between FEP and EGF, IL-1β and smoking. Treatment with antipsychotic drugs resulted in a statistically significant amelioration of the symptoms of psychosis, but caused a significant increase in the body mass index (BMI) of patients. Levels of EGF, IL-2, VEGF, IL-6, IFN-γ, IL-4, IL-8 and IL-1α were significantly lower in treated FEP patients compared to premedication levels.

CONCLUSIONS

According to the present study, EGF and IL-1β are markers of FEP. Antipsychotic drug treatment resulted in a significant clinical improvement of FEP patients and the suppression of positive symptoms was correlated with the decreased levels of EGF, IL-2 and IL-4. EGF was the strongest marker of FEP and treatment efficiency among the measured cytokines and growth factors.

Cognitive enhancing agents in schizophrenia and bipolar disorder

Cognitive dysfunction is a core feature of schizophrenia and is also present in bipolar disorder (BD). Whereas decreased intelligence precedes the onset of psychosis in schizophrenia and remains relatively stable thereafter; high intelligence is a risk factor for bipolar illness but cognitive function decreases after onset of symptoms. While in schizophrenia, many studies have been conducted on the development of cognitive enhancing agents; in BD such studies are almost non-existent. This review focuses on the pharmacological agents with putative effects on cognition in both schizophrenia and bipolar illness; specifically agents targeting the dopaminergic, cholinergic and glutamatergic neurotransmitter pathways in schizophrenia and the cognitive effects of lithium, anticonvulsants and antipsychotics in BD. In the final analysis we conclude that cognitive enhancing agents have not yet been produced convincingly for schizophrenia and have hardly been studied in BD. Importantly, studies should focus on other phases of the illness. To be able to treat cognitive deficits effectively in schizophrenia, patients in the very early stages of the illness, or even before - in the ultra-high risk stages - should be targeted. In contrast, cognitive deficits occur later in BD, and therefore drugs should be tested in BD after the onset of illness. Hopefully, we will then find effective drugs for the incapacitating effects of cognitive deficits in these patients.

Altered activation of innate immunity associates with white matter volume and diffusion in first-episode psychosis

First-episode psychosis (FEP) is associated with inflammatory and brain structural changes, but few studies have investigated whether systemic inflammation associates with brain structural changes in FEP. Thirty-seven FEP patients (median 27 days on antipsychotic medication), and 19 matched controls were recruited. Serum levels of 38 chemokines and cytokines, and cardiovascular risk markers were measured at baseline and 2 months later. We collected T1- and diffusion-weighted MRIs with a 3 T scanner from the patients at baseline. We analyzed the association of psychosis-related inflammatory markers with gray and white matter (WM) volume using voxel-based morphometry and WM diffusion using tract-based spatial statistics with whole-brain and region-of-interest (ROI) analyses. FEP patients had higher CCL22 and lower TGFα, CXCL1, CCL7, IFN-α2 and ApoA-I than controls. CCL22 decreased significantly between baseline and 2 months in patients but was still higher than in controls. The association between inflammatory markers and FEP remained significant after adjusting for age, sex, smoking and BMI. We did not observe a correlation of inflammatory markers with any symptoms or duration of antipsychotic treatment. Baseline CCL22 levels correlated negatively with WM volume and positively with mean diffusivity and radial diffusivity bilaterally in the frontal lobes in ROI analyses. Decreased serum level of ApoA-I was associated with smaller volume of the medial temporal WM. In whole-brain analyses, CCL22 correlated positively with mean diffusivity and radial diffusivity, and CXCL1 associated negatively with fractional anisotropy and positively with mean diffusivity and radial diffusivity in several brain regions. This is the first report to demonstrate an association between circulating chemokine levels and WM in FEP patients. Interestingly, CCL22 has been previously implicated in autoimmune diseases associated with WM pathology. The results suggest that an altered activation of innate immunity may contribute to WM damage in psychotic disorders.

Pathophysiological mechanisms of increased cardiometabolic risk in people with schizophrenia and other severe mental illnesses

Patients with schizophrenia have increased mortality and morbidity compared with the general population. These patients have a 20-year shorter lifespan than peers without schizophrenia, mainly due to premature cardiovascular disease, suicide, and cancer. Patients with severe mental illness are at increased risk for cardiovascular disease related to increased incidence of diabetes, hypertension, smoking, poor diet, obesity, dyslipidaemia, metabolic syndrome, low physical activity, and side-effects of antipsychotic drugs. Some second-generation antipsychotics (eg, clozapine, olanzapine, quetiapine, and risperidone) are associated with an increased risk of weight gain and obesity, impaired glucose tolerance and new-onset diabetes, hyperlipidaemia, and cardiovascular disease. The mechanisms by which schizophrenia and patients with severe mental illness are susceptible to cardiometabolic disorders are complex and include lifestyle risks and direct and indirect effects of antipsychotic drugs. An understanding of these risks might lead to effective interventions for prevention and treatment of cardiometabolic disorders in schizophrenia and severe mental illness.

IgG dynamics of dietary antigens point to cerebrospinal fluid barrier or flow dysfunction in first-episode schizophrenia

Schizophrenia is a complex brain disorder that may be accompanied by idiopathic inflammation. Classic central nervous system (CNS) inflammatory disorders such as viral encephalitis or multiple sclerosis can be characterized by incongruent serum and cerebrospinal fluid (CSF) IgG due in part to localized intrathecal synthesis of antibodies. The dietary antigens, wheat gluten and bovine milk casein, can induce a humoral immune response in susceptible individuals with schizophrenia, but the correlation between the food-derived serological and intrathecal IgG response is not known. Here, we measured IgG to wheat gluten and bovine milk casein in matched serum and CSF samples from 105 individuals with first-episode schizophrenia (n=75 antipsychotic-naïve), and 61 controls. We found striking correlations in the levels of IgG response to dietary proteins between serum and CSF of schizophrenia patients, but not controls (schizophrenia, R(2)=0.34-0.55, p⩽0.0001; controls R(2)=0.05-0.06, p>0.33). A gauge of blood-CSF barrier permeability and CSF flow rate, the CSF-to-serum albumin ratio, was significantly elevated in cases compared to controls (p⩽0.001-0.003). Indicators of intrathecal IgG production, the CSF IgG index and the specific Antibody Index, were not significantly altered in schizophrenia compared to controls. Thus, the selective diffusion of bovine milk casein and wheat gluten antibodies between serum and CSF in schizophrenia may be the function of a low-level anatomical barrier dysfunction or altered CSF flow rate, which may be transient in nature.

The multifactorial interplay of diet, the microbiome and appetite control: current knowledge and future challenges

The recent availability of high-throughput nucleic acid sequencing technologies has rapidly advanced approaches to analysing the role of the gut microbiome in governance of human health, including gut health, and also metabolic, cardiovascular and mental health,inter alia. Recent scientific studies suggest that energy intake (EI) perturbations at the population level cannot account for the current obesity epidemic, and significant work is investigating the potential role of the microbiome, and in particular its metabolic products, notably SCFA, predominantly acetate, propionate and butyrate, the last of which is an energy source for the epithelium of the large intestine. The energy yield from dietary residues may be a significant factor influencing energy balance. This review posits that the contribution towards EI is governed by EI diet composition (not just fibre), the composition of the microbiome and by the levels of physical activity. Furthermore, we hypothesise that these factors do not exist in a steady state, but rather are dynamic, with both short- and medium-term effects on appetite regulation. We suggest that the existing modelling strategies for bacterial dynamics, specifically for growth in chemostat culture, are of utility in understanding the dynamic interplay of diet, activity and microbiomic organisation. Such approaches may be informative in optimising the application of dietary and microbial therapy to promote health.

The Role of Infections and Autoimmune Diseases for Schizophrenia and Depression: Findings from Large-Scale Epidemiological Studies

An immunologic component to schizophrenia and depression has been increasingly recognized, which has led to extensive research into the associations with infections and autoimmune diseases. Large-scale nationwide epidemiological studies have displayed an increased prevalence of both autoimmune diseases and infections among persons with schizophrenia and depression. Autoimmune diseases, and especially the number of infections requiring hospitalization, increase the risk of schizophrenia and depression in a dose–response relationship. Infections are a common exposure and a broad spectrum of infections are associated with schizophrenia and depression. Particularly the autoimmune diseases with a potential presence of brain-reactive antibodies were associated with psychiatric disorders. However, the associations seem to be bidirectional, since the risk of autoimmune diseases and infections is also increased after diagnosis with schizophrenia and depression. The risk of autoimmune diseases was particularly increased in individuals with prior hospital contacts for infections.

It has been suggested that inflammation and autoimmunity could be involved in the etiology and pathogenesis of some patients with symptoms of schizophrenia and depression. The psychiatric symptoms can be directly triggered by immune components, such as brain-reactive antibodies and cytokines, or infections reaching the central nervous system (CNS), or be secondary to systemic inflammation indirectly affecting the brain. However, the associations could also be caused by shared genetic factors, other environmental factors, or common etiological components. Nonetheless, autoimmune diseases and infections should be considered by clinicians in the treatment of individuals with psychiatric symptoms, since treatment would probably improve the psychiatric symptoms, quality of life, and the survival of the individuals.

The SHP-1 expression is associated with cytokines and psychopathological status in unmedicated first episode schizophrenia patients

BACKGROUND

Recent lines of research have boosted awareness of the immunological facets of schizophrenia. However, associations with protein tyrosine phosphatase regulators have never been reported. The aim of our study was to investigate the expression and promoter status methylation of phosphatase SHP-1, a key negative regulator of the inflammatory process, in Peripheral blood mononuclear cells (PBMCs) of Schizophrenic patients.

METHODS

We enrolled fifty-four (28 men and 26 women) unmedicated first episode subjects (SC) who met DSM-IV and thirty-eight (22 men and 16 women) healthy controls (HC). The SC psychopathological status was assessed using the Positive and Negative Syndrome Scale. We evaluated SHP-1 expression by Quantitative Real-time PCR (qPCR) and Western blotting (WB) methods and promoter status methylation through PCR bisulfate. IKK/NFkB signaling was detected by WB, and medium and plasma levels of pro-inflammatory cytokines (IL-1β, IL-2, and TNF-α) by the ELISA method. SHP-1 was silenced by treating cells with specific siRNA.

RESULTS

We found a significantly lower level of SHP-1 gene expression in PBMCs from SC vs. HC, consistently with which the promoter region analyzed presented significant hypermethylation. Silencing of SHP-1 expression induced higher activation of IKK/NF-kB signaling and pro-inflammatory cytokine production in ex vivo PBMCs from both SC and HC. Linear regression among patients generated a model in which SHP-1 expression explained 30% of the clinical negative symptom variance (adjusted R(2)=0.30, ANOVA p<0.001).

CONCLUSIONS

Our findings are the first to suggest that impairment of SHP-1 expression is involved in the physiopathology of schizophrenia, opening fruitful new avenues for ameliorating treatment at least of negative symptoms.

Chronic schizophrenia is associated with over-expression of the interleukin-2 receptor gamma gene

Altered immune response, including low-grade inflammatory processes, is involved in the pathogenesis of schizophrenia, a chronic psychiatric disorder with complex etiology. Distinct gene variants of a number of pro-inflammatory and chemotactic cytokines together with their receptors associate with this disorder. Interleukin-2 receptor gamma (IL-2RG) represents an important signaling component of many interleukin receptors and so far, no data on the functional state of this receptor in schizophrenia have been reported. The aim of this study was to investigate mRNA expression of the IL2RG gene (IL2RG) in schizophrenia patients in comparison with healthy subjects (controls). Total RNA was isolated from peripheral blood of 66 schizophrenia patients and 99 healthy subjects of Armenian population. The mRNA expression was determined by quantitative real-time polymerase chain reaction (RT-PCR) using PSMB2 as housekeeping gene. IL2RG mRNA expression was upregulated in peripheral blood of patients in comparison with controls (patients vs. controls, median [interquartile range]: 2.080 [3.428-1.046] vs. 0.324 [0.856-0.000], p<0.0001). In conclusion, our findings suggest that over-expression of the IL2RG gene may be implicated in altered immune response in schizophrenia and contribute to the pathomechanisms of this disorder.

Identification of subgroups of schizophrenia patients with changes in either immune or growth factor and hormonal pathways

Schizophrenia is a heterogeneous disorder normally diagnosed using the Diagnostic and Statistical Manual of Mental Disorders criteria. However, these criteria do not necessarily reflect differences in underlying molecular abnormalities of the disorder. Here, we have used multiplexed immunoassay analyses to measure immune molecules, growth factors, and hormones important to schizophrenia in acutely ill antipsychotic-naive patients (n = 180) and matched controls (n = 398). We found that using the resulting molecular profiles, we were capable of separating schizophrenia patients into 2 significantly distinct subgroups with predominant molecular abnormalities in either immune molecules or growth factors and hormones. These molecular profiles were tested using an independent cohort, and this showed the same separation into 2 subgroups. This suggests that distinct abnormalities occur in specific molecular pathways in schizophrenia patients. This may be of relevance for intervention studies that specifically target particular molecular mechanisms and could be a first step to further define the complex schizophrenia syndrome based on molecular profiles.

Seroreactive marker for inflammatory bowel disease and associations with antibodies to dietary proteins in bipolar disorder

OBJECTIVES

Immune sensitivity to wheat glutens and bovine milk caseins may affect a subset of individuals with bipolar disorder. Digested byproducts of these foods are exorphins that have the potential to impact brain physiology through action at opioid receptors. Inflammation in the gastrointestinal (GI) tract might accelerate exposure of food antigens to systemic circulation and help explain elevated gluten and casein antibody levels in individuals with bipolar disorder.

METHODS

We measured a marker of GI inflammation, anti-Saccharomyces cerevisiae antibodies (ASCA), in non-psychiatric controls (n = 207), in patients with bipolar disorder without a recent onset of psychosis (n = 226), and in patients with bipolar disorder with a recent onset of psychosis (n = 38). We compared ASCA levels to antibodies against gluten, casein, Epstein-Barr virus (EBV), herpes simplex virus 1 (HSV-1), influenza A, influenza B, measles, and Toxoplasma gondii.

RESULTS

Elevated ASCA conferred a 3.5-4.4-fold increased odds ratio of disease association (age-, race-, and gender-corrected multinomial logistic regressions, p ≤ 0.00001) that was independent of type of medication received. ASCA correlated with food antibodies in both bipolar disorder groups (R(2)  = 0.29-0.59, p ≤ 0.0005), and with measles and T. gondii immunoglobulin G (IgG) in the recent onset psychosis bipolar disorder group (R(2)  = 0.31-0.36, p ≤ 0.004-0.01).

CONCLUSIONS

Elevated seropositivity of a GI-related marker and its association with antibodies to food-derived proteins and self-reported GI symptoms suggest a GI comorbidity in at least a subgroup of individuals with bipolar disorder. Marker seroreactivity may also represent part of an overall heightened activated immune state inherent to this mood disorder.

Brain-derived neurotrophic factor blood levels are decreased in schizophrenia patients and associate with rs6265 genotypes

OBJECTIVES

A growing number of studies implicate brain-derived neurotrophic factor (BDNF), an important promoter of synaptic transmission and neural plasticity, in the pathogenesis of schizophrenia. However, the existing data are controversial, that may reflect population differences between studied groups.

DESIGN AND METHODS

In the present study we performed a comparative analysis of BDNF plasma levels and its relation with rs6265 (G196A; Val66Met) polymorphism of BDNF gene (BDNF) in schizophrenia-affected and healthy subjects (controls) of the Armenian population. To check the influence of antipsychotics on BDNF plasma levels both medicated and non-medicated patients were involved in this study. Patients with paranoid form of schizophrenia chronically treated with typical antipsychotics (n=103), age- and sex-matched controls (n=105), and 25 antipsychotic-naive first-episode schizophrenia patients were involved. The levels of BDNF in the blood plasma were measured with a solid-phase enzyme-linked immunosorbent assay.

RESULTS

Decreased plasma levels of BDNF in both medicated and non-medicated schizophrenia patients compared to controls were observed. No significant difference in BDNF levels between medicated and non-medicated patients was detected. It was also detected that, compared to individuals homozygous for the standard allele (G/G) of rs6265, carriers of the rs6265 minor allele (A/G+A/A), which is significantly more frequent in schizophrenia patients than in controls, had decreased BDNF levels.

CONCLUSIONS

The data obtained suggested that the pathogenesis of schizophrenia is characterized by genetically predetermined decreased blood levels of BDNF. These results indicated that genetically determined alterations of neuroimmune modulators may be among the risk factors of schizophrenia and contribute to disease-specific pathologic changes in functional activity of both the neuronal synaptic plasticity and the immune system.

Cytokine alterations in first-episode schizophrenia patients before and after antipsychotic treatment

Schizophrenia has been associated with central nervous system and peripheral immune system imbalances. However, most studies have not yielded conclusive results due to limitations such as small sample size, dissimilarities in the clinical status of patients and the high variability of cytokine levels within the normal human population. Here, we have attempted to account for these limitations by carrying out standardised multiplex immunoassay analyses of 9 cytokines in serum from 180 antipsychotic-naïve first-episode schizophrenia patients and 350 matched controls across 5 clinical cohorts. All subjects were matched for potential confounding factors including age, gender, smoking and body mass index. We found that the levels of interleukin (IL)-1RA, IL-10 and IL-15 were increased significantly in patients across the cohorts. We also found that the levels of IL-1RA and IL-10 were decreased in 32 patients who had been followed up and treated for 6 weeks with atypical antipsychotics. Interestingly, we found that the changes in IL-10 levels were significantly correlated with the improvements in negative, general and total symptom scores. These results indicate that mixed pro- and anti-inflammatory responses may be altered in first onset patients, suggesting a role in the aetiology of schizophrenia. The finding that only the anti-inflammatory cytokine IL-10 responded to treatment in parallel with symptom improvement suggests that this could be used as a potential treatment response biomarker in future studies of schizophrenia.

Chemokines and chemokine receptors in mood disorders, schizophrenia, and cognitive impairment: a systematic review of biomarker studies

The search for immune biomarkers in psychiatric disorders has primarily focused on pro-inflammatory cytokines. Other immune proteins including chemokines have been relatively neglected in such studies. Recent evidence has implicated chemokines in many neurobiological processes potentially relevant to psychiatric disorders, beyond their classical chemotactic functions. These may include neuromodulator effects, neurotransmitter-like effects, and direct/indirect regulation of neurogenesis. This systematic review presents the existing early evidence which supports an association of many chemokines with the psychiatric disorders: depression, bipolar disorder, schizophrenia, mild cognitive impairment and Alzheimer's disease. The non-specific association of chemokines including CXCL8 (IL-8), CCL2 (MCP-1), CCL3 (MIP-1α) and CCL5 (RANTES) with these disorders across diagnostic categories implies a generalised involvement of many chemokine systemic with psychiatric disease. Additional chemokines with great mechanistic relevance including CXCL12 (SDF-1) and CX3CL1 (fractalkine) have been rarely reported in the existing human literature and should be included in future clinical studies. The potential utility of these proteins as pathologically relevant biomarkers or therapeutic targets should be considered by future clinical and translational research.