Cognition and psychopathology in first-episode psychosis: are they related to inflammation?

Altered neutrophil-to-lymphocyte ratio in patients with non-affective first episode psychosis and its relationship with symptom severity and cognitive impairment

Signatures of immune dysregulation as clinical biomarker for psychosis have remained unclear. We aimed to compare the Neutrophil-to-lymphocyte ratio (NLR) of patients with acute non-affective first-episode psychosis (FEP) with healthy controls after accounting for emotional states. We also explored the associations of NLR with symptom severity, onset profile and cognitive functions. The NLR was enumerated from complete blood count taken within a week of assessment. All FEP patients were rated on the Positive and Negative Syndrome Scale (PANSS) and the Clinician Global Impression-Severity (CGI-S) with verbal memory and executive functions assessed with the Cambridge Neuropsychological Test Automated Battery. Prevailing emotional state was measured with Beck Depression Inventory-II and Beck Anxiety Inventory. Out of seventy-nine consecutive FEP patients presenting to the study site, twenty-seven subjects were eligible and recruited. Twenty-seven age-/sex-matched controls were recruited. FEP patients had an NLR of 1.886 over the controls after accounting for scores on emotional states. The NLR of FEP patients was positively associated with CGI-S scores, PANSS positive symptom, disorganization and excitation scores. There was no significant correlation between NLR with the duration of untreated psychosis and cognitive performances. These findings support using NLR as a clinical biomarker in FEP, purporting further prospective study to measure NLR changes in the course of treatment.

Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode

BACKGROUND

Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder.

METHODS

The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status.

RESULTS

Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001).

CONCLUSIONS

Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent.

A machine learning approach on whole blood immunomarkers to identify an inflammation-associated psychosis onset subgroup

Psychosis onset is a transdiagnostic event that leads to a range of psychiatric disorders, which are currently diagnosed through clinical observation. The integration of multimodal biological data could reveal different subtypes of psychosis onset to target for the personalization of care. In this study, we tested the existence of subgroups of patients affected by first-episode psychosis (FEP) with a possible immunopathogenic basis. To do this, we designed a data-driven unsupervised machine learning model to cluster a sample of 127 FEP patients and 117 healthy controls (HC), based on the peripheral blood expression levels of 12 psychosis-related immune gene transcripts. To validate the model, we applied a resampling strategy based on the half-splitting of the total sample with random allocation of the cases. Further, we performed a post-hoc univariate analysis to verify the clinical, cognitive, and structural brain correlates of the subgroups identified. The model identified and validated two distinct clusters: 1) a FEP cluster characterized by the high expression of inflammatory and immune-activating genes (IL1B, CCR7, IL12A and CXCR3); 2) a cluster consisting of an equal number of FEP and HC subjects, which did not show a relative over or under expression of any immune marker (balanced subgroup). None of the subgroups was related to specific symptoms dimensions or longitudinal diagnosis of affective vs non-affective psychosis. FEP patients included in the balanced immune subgroup showed a thinning of the left supramarginal and superiorfrontal cortex (FDR-adjusted p-values < 0.05). Our results demonstrated the existence of a FEP patients' subgroup identified by a multivariate pattern of immunomarkers involved in inflammatory activation. This evidence may pave the way to sample stratification in clinical studies aiming to develop diagnostic tools and therapies targeting specific immunopathogenic pathways of psychosis.

The influence of modifiable cardiovascular risk factors on cognition, functioning, and inflammatory markers in first-episode psychosis: Results from a 2-year follow-up study

To explore the influence of cardiovascular risk factors (CVRFs) on cognitive symptoms, functional impairment, and systemic inflammatory markers in first-episode psychosis (FEP) patients at baseline and 2-year follow-up. Method: In a sample of 70 FEP patients and 85 age- and sex-matched healthy controls, we assessed nine modifiable CVRFs. All participants were classified into two subgroups according to their CVRF profile: lower (0-1 CVRFs) or higher (≥2 CVRFs). The following outcomes were measured at baseline and 2-year follow-up: cognition; functional outcomes; and white blood cell (WBC) subtype. Adjusted general linear models were conducted to study the effect of diagnosis and CVRF profile on cognition, functioning, WBC, and longitudinal changes in these variables. At baseline, FEP patients with a higher CVRF profile showed a significantly slower performance on the TMT-A test for psychomotor speed and higher lymphocyte levels than patients with a lower CVRF profile. No longitudinal changes were observed in primary outcomes at 2-year follow-up. Among FEP patients with a higher CVRF profile, slower psychomotor speed performance did not correlate with increased lymphocyte levels. Our findings suggest that the cognitive effects of CVRFs manifest early in the course of psychosis, thus highlighting the importance of targeting both CVRFs and cognitive deficits in FEP.

The Influence of Oxytocin and Prolactin During a First Episode of Psychosis: The Implication of Sex Differences, Clinical Features, and Cognitive Performance

BACKGROUND

Approximately 3% of the population suffers a first episode of psychosis (FEP), and a high percentage of these patients subsequently relapse. Because the clinical course following a FEP is hard to predict, it is of interest to identify cognitive and biological markers that will help improve the diagnosis, treatment, and outcome of such events and to define new therapeutic targets. Here we analyzed the plasma oxytocin and prolactin levels during an FEP, assessing their correlation with clinical and cognitive features.

METHODS

The oxytocin and prolactin in plasma was measured in 120 FEP patients and 106 healthy controls, all of whom were subjected to a clinical and neuropsychological assessment. Most patients were under antipsychotics. Statistical analyses aimed to identify factors associated with the FEP and to search for associations between the variables. This study is preliminary and exploratory because the P-values were not corrected for multiple comparisons.

RESULTS

FEP patients had less oxytocin, more prolactin, and a poor premorbid IQ, and they performed worse in sustained attention. Male patients with higher prolactin levels experienced more severe psychotic symptoms and required higher doses of antipsychotics. Low oxytocin was associated with poor sustained attention in women, whereas low oxytocin and high prolactin in men correlated with better performance in sustained attention.

CONCLUSION

Low oxytocin, high prolactin, and poor premorbid IQ and sustained attention are factors associated with an FEP, representing potential therapeutic targets in these patients. These biological factors and cognitive domains might play an important role during a FEP, which could help us to develop new strategies that improve the outcomes of this disorder and that should perhaps be gender specific.

COX-2 pathway is upregulated in ultra-high risk individuals for psychosis

BACKGROUND

The identification of Ultra-High Risk (UHR) individuals is thought to be useful for early intervention to improve psychosis outcomes. However, transition rates vary widely, and there is an effort to make these criteria more specific and accurate. Neuroinflammation has been discussed in the pathophysiology of psychosis. The metabolism of eicosanoids is a key process in inflammatory states. Therefore, we investigated whether the study of the inflammatory COX-2 pathway through the quantification of the eicosanoid levels can be a useful approach for the characterisation of UHR individuals.

METHODS

One hundred and twenty-two individuals were included in this study (67 UHR and 55 controls) based on performance on the Prodromal Questionnaire. UHR status was assessed by Structured Interview for Prodromal Syndromes (SIPS). We determined the levels of Prostaglandin F_2α (PGF_2α), Prostaglandin E₂ (PGE₂), and Thromboxane B₂ (TxB₂) in plasma using ELISA assays.

RESULTS

Concentrations of PGE₂ and TxB₂ were increased in UHR compared to controls (p = 0.01 and p < 0.05, respectively). PGE₂ and PGF_2α levels were correlated to negative symptoms (p < 0.01 and p < 0.05), whereas TxB₂ correlated with positive symptoms (p = 0.05) as assessed by the SIPS.

CONCLUSIONS

Our findings suggest that overactivation of the COX-2 pathway may be related to an increased risk for psychosis. However, our data do not allow us to draw conclusions related to the cause-effect mechanisms. Future studies should determine whether the levels of the eicosanoids have a predictive value for the transition of UHR to frank psychosis.

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

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

Environmental Risk Factors and Psychotic-like Experiences in Children Aged 9-10

OBJECTIVE

Research implicates environmental risk factors, including correlates of urbanicity, deprivation, and environmental toxins, in psychotic-like experiences (PLEs). The current study examined associations between several types of environmental risk factors and PLEs in school-age children, whether these associations were specific to PLEs or generalized to other psychopathology, and examined possible neural mechanisms for significant associations.

METHOD

The current study used cross-sectional data from 10,328 children 9-10 years old from the Adolescent Brain Cognitive Development (ABCD) Study. Hierarchical linear models examined associations between PLEs and geocoded environmental risk factors and whether associations generalized to internalizing/externalizing symptoms. Mediation models examined evidence of structural magnetic resonance imaging abnormalities (eg, intracranial volume) potentially mediating associations between PLEs and environmental risk factors.

RESULTS

Specific types of environmental risk factors, namely, measures of urbanicity (eg, drug offense exposure, less perception of neighborhood safety), deprivation (eg, overall deprivation, poverty rate), and lead exposure risk, were associated with PLEs. These associations showed evidence of stronger associations with PLEs than internalizing/externalizing symptoms (especially overall deprivation, poverty, drug offense exposure, and lead exposure risk). There was evidence that brain volume mediated between 11% and 25% of associations of poverty, perception of neighborhood safety, and lead exposure risk with PLEs.

CONCLUSION

Although in the context of cross-sectional analyses, this evidence is consistent with neural measures partially mediating the association between PLEs and environmental exposures. This study also replicated and extended recent findings of associations between PLEs and environmental exposures, finding evidence for specific associations with correlates of urbanicity, deprivation, and lead exposure risk.

Verbal memory measurement towards digital perspectives in first-episode psychosis: A review

BACKGROUND

Even in the early phases of psychotic spectrum illnesses such as schizophrenia, patients can experience cognitive decline or deficits prior to the onset of psychotic symptoms such as delusions and hallucinations. In this systematic review, we assessed which verbal memory assessments are most widely used in first-episode psychosis and may be applied via digital technologies (smartphone applications, etc.) for use in early detection.

METHODS

In November 2019, we searched for studies measuring verbal memory in first episode psychosis or schizophrenia over the past 10 years on PubMed and PsycINFO. We screened abstracts of these studies and excluded review studies. Full-texts of included studies were used to identify the verbal memory measurement tests, follow-up frequencies, and sample sizes.

RESULTS

We screened 233 reports and found that 120 original research studies measured verbal memory in first episode psychosis over the past 10 years. Four of these studies specified using a computer, 24 (20%) used a paper-pen format, 1(1%) used both, and 91 (76%) studies did not specify their administration tools or suggest there were offered in digital formats. Thirty-five (30%) studies had follow-up measurements of verbal memory, while 85 (70%) had only a single verbal memory measurement.

DISCUSSION

While many scales are commonly used to measure verbal memory in first episode psychosis, they are not often administered via digital technology. There is an emerging opportunity to administer these and other tests via digital technologies for expanding access to early detection of cognitive decline in clinical high risk and first-episode psychosis.

The association of cognitive performance and IL-6 levels in schizophrenia is influenced by age and antipsychotic treatment

Aims: Recent findings suggest that cognitive impairment can be associated with inflammation and immune changes in schizophrenia. We aimed to study possible associations between cytokine levels and cognitive performance in a sample of patients with schizophrenia.Methods: Cognition was assessed with the brief assessment of cognition in schizophrenia in 63 clinically stable outpatients with schizophrenia. Blood was collected and cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, IFN-γ) were measured by cytometric bead array method. Psychopathological scales were also applied.Results: IL-6 correlated negatively with general cognitive performance (rho = -0.395, p = .017) and positively with antipsychotic dose (rho = 0.412, p = .004). Multiple regression analysis showed that cognitive performance is associated with age and antipsychotic dose (p = .000 and p = .033).Conclusion: The association between IL-6 levels and cognitive performance is dependent on age and antipsychotic dose.

Effects of inflammation on the kynurenine pathway in schizophrenia - a systematic review

Background

In the last decade, there has been growing evidence that an interaction exists between inflammation and the kynurenine pathway in schizophrenia. Additionally, many authors found microglial activation in cases of schizophrenia due to inflammatory mechanisms related mostly to an increase of pro-inflammatory cytokines. In order to gain new insights into the pathophysiology of schizophrenia, it is important to incorporate the latest published evidence concerning inflammatory mechanisms and kynurenine metabolism. This systematic review aims to collect reliable recent findings within the last decade supporting such a theory.

Methods

A structured search of electronic databases was conducted for publications between 2008 and 2018 to identify eligible studies investigating patients with schizophrenia/psychosis and the relationship between inflammation and kynurenine pathway. Applicable studies were systematically scored using the NIH Quality Assessment Tools. Two researchers independently extracted data on diagnosis (psychosis/schizophrenia), inflammation, and kynurenine/tryptophan metabolites.

Results

Ten eligible articles were identified where seven studies assessed blood samples and three assessed cerebrospinal fluid in schizophrenic patients.

Of these articles:

Four investigated the relationship between immunoglobulins and the kynurenine pathway and found correlations between IgA-mediated responses and levels of tryptophan metabolites (i.e., kynurenine pathway).

Five examined the correlation between cytokines and kynurenine metabolites where three showed a relationship between elevated IL-6, TNF-α concentrations, and the kynurenine pathway.

Only one study discovered correlations between IL-8 and the kynurenine pathway.

Two studies showed correlations with lower concentrations of IL-4 and the kynurenine pathway.

Moreover, this systematic review did not find a significant correlation between CRP (n = 1 study), IFN-γ (n = 3 studies), and the kynurenine pathway in schizophrenia.

Interpretation

These results emphasize how different inflammatory markers can unbalance the tryptophan/kynurenine pathway in schizophrenia. Several tryptophan/kynurenine pathway metabolites are produced which can, in turn, underlie different psychotic and cognitive symptoms via neurotransmission modulation. However, due to heterogeneity and the shortage of eligible articles, they do not robustly converge to the same findings. Hence, we recommend further studies with larger sample sizes to elucidate the possible interactions between the various markers, their blood vs. CSF ratios, and their correlation with schizophrenia symptoms.

Regulation of inflammatory pathways in schizophrenia: A comparative study with bipolar disorder and healthy controls

Background

Immune-inflammatory processes have been implicated in schizophrenia (SCH), but their specificity is not clear.

Main aim

To identify potential differential intra-/intercellular biochemical pathways controlling immune-inflammatory response and their oxidative-nitrosative impact on SCH patients, compared with bipolar disorder (BD) patients and healthy controls (HC).

Methods

Cross-sectional, naturalistic study of a cohort of SCH patients (n=123) and their controls [BD (n=102) and HC (n=80)].

Statistical analysis

ANCOVA (or Quade test) controlling for age and gender when comparing the three groups, and controlling for age, gender, length of illness, cigarettes per day, and body mass index (BMI) when comparing SCH and BD.

Results

Pro-inflammatory biomarkers: Expression of COX-1 was statistically higher in SCH and BD than HC (P<0.0001; P<0.0001); NFκB and PGE2 were statistically higher in SCH compared with BD (P=0.001; P<0.0001) and HC (P=0.003; P<0.0001); NLRP3 was higher in BD than HC (P=0.005); and CPR showed a gradient among the three groups. Anti-inflammatory biomarkers: BD patients had lower PPARγ and higher 15d-PGJ2 levels than SCH (P=0.005; P=0.008) and HC (P=0.001; P=0.001). Differences between SCH and BD: previous markers of SCH (NFκB and PGE2) and BD (PPARγ and 15d-PGJ2) remained statistically significant and, interestingly, iNOS and COX-2 (pro-inflammatory biomarkers) levels were statistically higher in SCH than BD (P=0.019; P=0.040).

Conclusions

This study suggests a specific immune-inflammatory biomarker pattern for established SCH (NFκB, PGE2, iNOS, and COX-2) that differentiates it from BD and HC. In future, their pharmacological modulation may constitute a promising therapeutic target.

Glycated Haemoglobin Is Associated With Poorer Cognitive Performance in Patients With Recent-Onset Psychosis

BACKGROUND

Glucose abnormalities and cognitive alterations are present before the onset of schizophrenia. We aimed to study whether glucose metabolism parameters are associated with cognitive functioning in recent-onset psychosis (ROP) patients while adjusting for hypothalamic-pituitary adrenal (HPA) axis measures.

METHODS

Sixty ROP outpatients and 50 healthy subjects (HS) were studied. Cognitive function was assessed with the MATRICS Consensus Cognitive Battery. Glycated haemoglobin (HbA1_c), glucose, insulin, and C-peptide levels were determined in plasma. The HOMA-insulin resistance index was calculated. Salivary samples were obtained at home on another day to assess the cortisol awakening response and cortisol levels during the day. Univariate analyses were conducted to explore the association between glucose metabolism parameters and cognitive tasks. For those parameters that were more clearly associated with the cognitive outcome, multiple linear regression analyses were conducted to adjust for covariates. Each cognitive task was considered the dependent variable. Covariates were age, sex, education level, diagnosis, antipsychotic and benzodiazepine treatment, body mass index (BMI), smoking, and HPA axis measures. Potential interactions between diagnosis and glucose parameters were tested.

RESULTS

There were no significant differences in HPA axis measures or glucose parameters, with the exception of C-peptide (that was higher in ROP patients), between groups. ROP patients had a lower performance than HS in all cognitive tasks (p < 0.01 for all tasks). Of all glucose metabolism parameters, HbA1c levels were more clearly associated with cognitive impairment in cognitive tasks dealing with executive functions and visual memory in both ROP patients and HS. Multivariate analyses found a significant negative association between HbA1c and cognitive functioning in five cognitive tasks dealing with executive functions, visual memory and attention/vigilance (a ROP diagnosis by HbA1_c negative interaction was found in this latter cognitive domain, suggesting that HBA1_c levels are associated with impaired attention only in ROP patients).

CONCLUSIONS

Our study found that HbA1_c was negatively associated with cognitive functioning in both ROP patients and HS in tasks dealing with executive functions and visual memory. In ROP patients, HbA1_c was also associated with impaired attention. These results were independent of BMI and measures of HPA axis activity.

Effects of electroconvulsive therapy in the systemic inflammatory balance of patients with severe mental disorder

AIM

There is a great interest in the role of the immune system and the inflammatory balance as key mechanisms involved in the pathophysiology of severe mental disorders. Previous studies have indicated that electroconvulsive therapy (ECT) produces changes in certain inflammatory mediators or in the immune system response. This study aimed to explore the effects of ECT on the nuclear transcription factor κB (NFκB) pathway, a main regulatory pathway of the inflammatory/immune response.

METHODS

Thirty subjects with a severe mental disorder receiving treatment with ECT in our center were included. Thirteen systemic biomarkers related to the NFκB pathway were analyzed right before and 2 h after a single ECT session.

RESULTS

An ECT session significantly decreased the expression of NFκB (P = 0.035) and of the inducible nitric oxide synthase (P = 0.012), and the plasma levels of nitrites (P = 0.027), prostaglandin E₂ (P = 0.049), and 15-deoxy-PGJ₂ (P < 0.001). Decrease in plasmatic levels of nitrites was greater in females than in males (P = 0.021). A positive correlation between the ECT stimulus load and changes in the expression of NFkB was found (P = 0.036). Thiobarbituric acid reactive substance levels were decreased in treatment responders and increased in non-responders (P = 0.047).

CONCLUSION

Our study shows the effects that a single session of ECT produces on a canonical regulatory pathway of the inflammatory/innate immune system and the inflammatory balance. These biomarkers could be useful as treatment response targets and could help to clarify the biological basis of ECT action. These findings warrant greater attention in future investigations and in the translational significance of these data.

Knockdown of circulating C1 inhibitor induces neurovascular impairment, glial cell activation, neuroinflammation, and behavioral deficits

The cross-talk between blood proteins, immune cells, and brain function involves complex mechanisms. Plasma protein C1 inhibitor (C1INH) is an inhibitor of vascular inflammation that is induced by activation of the kallikrein-kinin system (KKS) and the complement system. Knockout of C1INH was previously correlated with peripheral vascular permeability via the bradykinin pathway, yet there was no evidence of its correlation with blood-brain barrier (BBB) integrity and brain function. In order to understand the effect of plasma C1INH on brain pathology via the vascular system, we knocked down circulating C1INH in wild-type (WT) mice using an antisense oligonucleotide (ASO), without affecting C1INH expression in peripheral immune cells or the brain, and examined brain pathology. Long-term elimination of endogenous C1INH in the plasma induced the activation of the KKS and peritoneal macrophages but did not activate the complement system. Bradykinin pathway proteins were elevated in the periphery and the brain, resulting in hypotension. BBB permeability, extravasation of plasma proteins into the brain parenchyma, activation of glial cells, and elevation of pro-inflammatory response mediators were detected. Furthermore, infiltrating innate immune cells were observed entering the brain through the lateral ventricle walls and the neurovascular unit. Mice showed normal locomotion function, yet cognition was impaired and depressive-like behavior was evident. In conclusion, our results highlight the important role of regulated plasma C1INH as it acts as a gatekeeper to the brain via the neurovascular system. Thus, manipulation of C1INH in neurovascular disorders might be therapeutically beneficial.

Blood cell count in antipsychotic-naive patients with non-affective psychosis

BACKGROUND

Schizophrenia is a complex medical entity with a reduced life expectancy, mostly due to an increased prevalence of cardiovascular diseases compared to the general population. An unbalanced immune response and a pro-inflammatory state might underlie this process. In treated patients, abnormal white blood cell (WBC), lymphocyte and neutrophil count suggests atypical immune response related to clinical variables. We aimed to test the hypothesis that newly diagnosed naïve patients with non-affective psychosis would show abnormal blood cell count values after controlling for potential confounding factors compared to matched controls.

METHODS

Seventy-five patients were compared with 80 controls matched for age, gender, body mass index and smoking. Analyses were conducted before and after controlling for smoking.

RESULTS

Patients and controls displayed similar mean values (×10³ /μL [SD]) for WBC count 7.02 [2.2] vs 6.50 [1.7] (P = .159), neutrophil count 4.25 [1.8] vs 3.84 [1.3] (P = .110) and monocyte count 0.43 [0.2] vs 0.40 [0.1] (P = .326). After controlling for smoking, 38 non-smoking patients showed a higher WBC and neutrophil count compared with 49 matched controls. Respective means of 7.01 [2.2] vs 5.97 [1.4] (P = .011) for WBC and 4.24 [1.9] vs 3.51 [1.2] (P = .028) for neutrophil count. Monocyte count showed an increased mean value 0.43 [0.2] vs 0.36 [0.1] with a trend towards signification (P = .063).

CONCLUSIONS

These results suggest that abnormal immune response is present before the effects of medication and other confounders had taken place. Increased immune parameters might underlie the high ratio of medical co-morbidities described in schizophrenia.

Early versus late stage schizophrenia. What markers make the difference?

OBJECTIVES

To identify the psychopathological, cognitive, functional, physical health and inflammatory markers that differentiate between early-stage schizophrenia (ESSCH) and late-stage schizophrenia (LSSCH).

METHODS

Cross-sectional, naturalistic study of 104 patients with SCH. The sample was divided in two groups: 35 ESSCH (≤7 years' duration of illness) and 69 LSSCH (>10 years' duration of illness).

STATISTICAL ANALYSIS

chi-square test and Student's t-test and ANCOVA (or Quade test) controlling for age, sex, BMI and number of cigarettes/day. Finally, a binomial logistic regression was made.

RESULTS

ESSCH show greater negative symptom severity (t = 2.465, p = 0.015), lower levels of IκBα (F = 7.644, p = 0.007), were more frequently classified as normal weight (40% vs 18.8%, p = 0.032) compared with LSSCH. The binomial logistic regression model included age (B = 0.127, p = 0.001) and IκBα (B = 0.025, p = 0.002) and accounted for 38.9% of the variance (model df =7, chi-square =41.841, p < 0.0001).

CONCLUSIONS

Age and IκBα are the unique markers that differentiate between ESSCH patients whose duration of illness is less than 7 years and LSSCH patients. These results support the hypothesis of toxicity of episodes and highlight the importance of preventing new episodes.

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

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

Salsalate as an adjunctive treatment for psychopathology and cognition in patients with schizophrenia: a pilot study

This pilot study examined the effect of adjunctive salsalate on psychopathology and cognition in patients with schizophrenia. This was a 12-week, open-label trial of salsalate (1.5 g, twice per day) in patients with schizophrenia. Psychopathology, cognition, and daily function were assessed at baseline and week 12 using various rating scales. Blood levels of inflammatory markers including white blood cell count, high-sensitivity C-reactive protein, and interleukin-6 levels were also measured. Eight patients completed the study. There was no significant change in any of the rating scales at week 12. However, there was a trend decrease in the Positive and Negative Syndrome Scale total score, and a trend improvement in the Brief University of California San Diego Performance-based Skills Assessment total score (58.3±11.4 vs. 53.5±11.9, P=0.072; 69.7±18.2 vs. 79.1±15.9, P=0.084, respectively). There was a trend improvement in quality of life as measured by the Quality of Life Scale total score (74.0±20.8 vs. 76.9±22.7, P=0.080). There was a significant decrease in white blood cell count (6.8±1.3 vs. 6.0±1.2 k/mm, P=0.022). There was no change in the levels of high-sensitivity C-reactive protein or interleukin-6 over 12 weeks (P's>0.1). Salsalate may have positive therapeutic effect in patients with schizophrenia. Future studies to examine potential benefits of salsalate as an adjunctive treatment to improve clinical symptoms and daily function in patients with schizophrenia are warranted.

Psychoneuroimmunology of mental disorders

The immune system is a key element in the organism's defence system and participates in the maintenance of homeostasis. There is growing interest in the aetiopathogenic and prognostic implications of the immune system in mental disorders, as previous studies suggest the existence of a dysregulation of the immune response and a pro-inflammatory state in patients with mental disorders, as well as an increased prevalence of neuropsychiatric symptoms in patients suffering from autoimmune diseases or receiving immune treatments. This study aims to conduct a narrative review of the scientific literature on the role of Psychoneuroimmunology in mental disorders, with special focus on diagnostic, prognostic and therapeutic issues. The development of this body of knowledge may bring in the future important advances in the vulnerability, aetiopathogenic mechanisms, diagnosis and treatment of some mental disorders.

A comparison of the neutrophil-lymphocyte, platelet-lymphocyte and monocyte-lymphocyte ratios in schizophrenia and bipolar disorder patients - a retrospective file review

Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR) have recently been used as indicators of inflammation. Higher MLR and PLR values have been determined in the euthymic and manic periods in patients with bipolar disorder compared to a control group. High NLR values were determined in the only study investigating this ratio in schizophrenia patients. The purpose of this study was to compare NLR, PLR and MLR values and complete blood count elements in patients receiving treatment and hospitalized due to schizophrenic psychotic episode and bipolar disorder manic episode. All patients meeting the inclusion criteria among subjects receiving treatment and hospitalized due to schizophrenia-psychotic episode and bipolar affective disorder-manic episode at the Ondokuz Mayıs University Medical Faculty Psychiatry Department, Turkey, in 2012-2016 were included in our study. A total of 157 healthy donors were included as a control group. White blood cell (WBC), neutrophil, lymphocyte, platelet and monocyte numbers were noted retrospectively from complete blood counts at time of admission, and NLR, PLR and MLR were calculated from these. NLR, PLR and MLR values and platelet numbers in this study were higher and lymphocyte numbers were lower in bipolar disorder patients compared to the controls. Elevation in NLR, MLR and PLR values and neutrophil numbers and lower lymphocyte numbers were determined in schizophrenia patients compared to the controls. Higher NLR and MLR values were found in schizophrenia patients compared to bipolar disorder. Findings of our study supported the inflammation hypothesis for schizophrenia and bipolar disorder.

Consensus paper of the WFSBP Task Force on Biological Markers: Criteria for biomarkers and endophenotypes of schizophrenia, part III: Molecular mechanisms

OBJECTIVES

Despite progress in identifying molecular pathophysiological processes in schizophrenia, valid biomarkers are lacking for both the disease and treatment response.

METHODS

This comprehensive review summarises recent efforts to identify molecular mechanisms on the level of protein and gene expression and epigenetics, including DNA methylation, histone modifications and micro RNA expression. Furthermore, it summarises recent findings of alterations in lipid mediators and highlights inflammatory processes. The potential that this research will identify biomarkers of schizophrenia is discussed.

RESULTS

Recent studies have not identified clear biomarkers for schizophrenia. Although several molecular pathways have emerged as potential candidates for future research, a complete understanding of these metabolic pathways is required to reveal better treatment modalities for this disabling condition.

CONCLUSIONS

Large longitudinal cohort studies are essential that pair a thorough phenotypic and clinical evaluation for example with gene expression and proteome analysis in blood at multiple time points. This approach might identify biomarkers that allow patients to be stratified according to treatment response and ideally also allow treatment response to be predicted. Improved knowledge of molecular pathways and epigenetic mechanisms, including their potential association with environmental influences, will facilitate the discovery of biomarkers that could ultimately be effective tools in clinical practice.

The Link Between the Immune System, Environment, and Psychosis

The last decade has witnessed a burgeoning interest in studies exploring the link between psychosis spectrum disorders (PSD) and altered immune function. While epidemiological and clinical studies point to evidence for increased peripheral inflammatory markers in PSD, it is not clear whether peripheral inflammation correlates with central inflammation in the brain. Furthermore, these studies are confounded by multiple methodological and disorder-related factors such as antipsychotic medications, smoking, obesity, and metabolic syndrome, all of which independently contribute to altered inflammation. Clinical and animal studies provide encouraging evidence that inflammatory processes can define trans-diagnostic neuropsychiatric domains such as positive/negative valence, affective dysregulation, and cognitive impairment. In this commentary, we speculate on whether inflammation-mediated pathways may serve as a final-common pathway for environmental risk factors of early-childhood adversity, adolescent cannabis use, social exclusion, and on the possible mechanisms mediating the pathophysiology of PSD. We propose an integrative framework and suggest future research strategies that may help disentangle the link between immune dysfunction and PSD.

Serum levels of interleukin-33 and its soluble form receptor (sST2) are associated with cognitive performance in patients with schizophrenia

OBJECTIVE

Changes in immune system have been reported in schizophrenia. This study aimed to evaluate the involvement of IL-33, a member of the IL-1 cytokine family, in schizophrenia and its association with cognitive performance in these patients.

METHODS

Forty patients with chronic schizophrenia and 40 healthy subjects participated in the study. Serum levels of IL-33 and sST2 (soluble form of the IL-33 receptor) were measured using enzyme-linked immunosorbent assay (ELISA). Patients were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS) and the Schizophrenia Cognition Rating Scale (SCoRS).

RESULTS

Patients with schizophrenia and controls presented similar serum levels of IL-33 and sST2. Levels of both markers were positively correlated with cognitive performance in patients with schizophrenia.

CONCLUSION

We found a significant correlation between IL-33 and sST2 levels and cognition in schizophrenia. Our results might help in the understanding of how immune markers are associated with cognitive impairment in schizophrenia. It remains to be determined whether the association between IL-33/sST2 and cognition is restricted to patients with schizophrenia.

A molecular Pathway Analysis Stresses the Role of Inflammation Towards Cognition in Schizophrenia

Background

Cognitive processes are impaired in Schizophrenia (SKZ). The nature of such impairment escapes definition.

Aim

Identification of a genetic profile at risk of cognitive impairment.

Object

Identifying a molecular pathways enriched for mutations associated with cognitive impairment.

Methods

Seven hundred and sixty-five individuals from the CATIE, M = 556, mean age = 40.93 ± 11.03 were included. Verbal memory was outcome. R and Plink served for the analyses. Inflation factor was controlled by lambda values. Input for the pathway analysis were SNPs associated with outcome (P < 0.05) genomewide.

Results

Gender (male, P = 2.34e–05;t = –4.26) and years of education (P = 1.57e–03;t = 6.502) were associated with verbal memory. Inflammation and oxidation were associated with outcome (Table 1, adj_P < 0.01).

Conclusions

Being male and poorly educated were associated with poorer verbal memory. Inflammation and the arachidonic acid pathway were enriched in mutations associated with poorer verbal memory. This finding is in line with previous reports [1,2,3].

Paliperidone reverts Toll-like receptor 3 signaling pathway activation and cognitive deficits in a maternal immune activation mouse model of schizophrenia

The pathophysiology of psychotic disorders is multifactorial, including alterations in the immune system caused by exogenous or endogenous factors. Epidemiological and experimental studies indicate that infections during the gestational period represent a risk factor to develop schizophrenia (SZ) along lifetime. Here, we tested the hypothesis that the antipsychotic paliperidone regulates immune-related brain effects in an experimental model of SZ. A well described prenatal immune activation model of SZ in mice by maternal injection of the viral mimetic poly(I:C) during pregnancy was used. Young-adult offspring animals (60PND) received paliperidone ip (0.05 mg/kg) for 21 consecutive days. One day after last injection, animals were submitted to a cognitive test and brain frontal cortex (FC) samples were obtained for biochemical determinations. The adults showed an activated innate immune receptor TLR-3 signaling pathway, oxidative/nitrosative stress and accumulation of pro-inflammatory mediators such as nuclear transcription factors (i.e., NFκB) and inducible enzymes (i.e., iNOS) in FC. Chronic paliperidone blocked this neuroinflammatory response possibly by the synergic activation and preservation of endogenous antioxidant/anti-inflammatory mechanisms such as NRF2 and PPARγ pathways, respectively. Paliperidone administration also stimulated the alternative polarization of microglia to the M2 anti-inflammatory profile. In addition, paliperidone treatment improved spatial working memory deficits of this SZ-like animal model. In conclusion, chronic administration of paliperidone to young-adult mice prenatally exposed to maternal immune (MIA) challenge elicits a general preventive anti-inflammatory/antioxidant effect at both intracellular and cellular polarization (M1/M2) level in FC, as well as ameliorates specific cognitive deficits.