Biomarcadores sanguíneos diferenciales de las dimensiones psicopatológicas de la esquizofrenia

HIV-Associated Neurocognitive Disorder: A Look into Cellular and Molecular Pathology

Despite combined antiretroviral therapy (cART) limiting HIV replication to undetectable levels in the blood, people living with HIV continue to experience HIV-associated neurocognitive disorder (HAND). HAND is associated with neurocognitive impairment, including motor impairment, and memory loss. HIV has been detected in the brain within 8 days of estimated exposure and the mechanisms for this early entry are being actively studied. Once having entered into the central nervous system (CNS), HIV degrades the blood-brain barrier through the production of its gp120 and Tat proteins. These proteins are directly toxic to endothelial cells and neurons, and propagate inflammatory cytokines by the activation of immune cells and dysregulation of tight junction proteins. The BBB breakdown is associated with the progression of neurocognitive disease. One of the main hurdles for treatment for HAND is the latent pool of cells, which are insensitive to cART and prolong inflammation by harboring the provirus in long-lived cells that can reactivate, causing damage. Multiple strategies are being studied to combat the latent pool and HAND; however, clinically, these approaches have been insufficient and require further revisions. The goal of this paper is to aggregate the known mechanisms and challenges associated with HAND.

Correlation between elevated serum interleukin-1β, interleukin-16 levels and psychiatric symptoms in patients with schizophrenia at different stages

BACKGROUND

There is increasing evidence that immune dysfunction plays an important role in the pathogenesis of schizophrenia. Meso Scale Discovery (MSD) is bioanalytical method, which can detect serum inflammatory factors in patients. MSD has higher sensitivities, capturing a narrower range of proteins compared to other methods typically used in similar studies. The present study was aimed to explore the correlation between the levels of serum inflammatory factors and psychiatric symptoms in patients with schizophrenia at different stages and investigate a wide panel of inflammatory factors as independent factors for the pathogenesis of schizophrenia.

METHODS

We recruited 116 participants, including patients with first-episode schizophrenia (FEG, n = 40), recurrence patients (REG, n = 40) with relapse-episode schizophrenia, and a control group (healthy people, HP, n = 36). Patients are diagnosed according to the DSM -V. The plasma levels of IFN-γ, IL-10, IL-1β, IL-2, IL-6, TNF-α, CRP, VEGF, IL-15, and IL-16 were tested by the MSD technique. Patient-related data was collected, including sociodemographic data, positive and negative symptom scale (PANSS), and brief psychiatric rating scale (BPRS) and subscale scores. The independent sample T test, χ2 test, Analysis of covariance (ANCOVA), the least significant difference method (LSD), Spearman's correlation test, binary logistic regression analysis and ROC curve analysis were used in this study.

RESULTS

There were significant differences in serum IL-1β (F = 2.37, P = 0.014) and IL-16 (F = 4.40, P < 0.001) levels among the three groups. The level of serum IL-1β in the first-episode group was significantly higher than in the recurrence group (F = 0.87, P = 0.021) and control group (F = 2.03, P = 0.013), but there was no significant difference between the recurrence group and control group (F = 1.65, P = 0.806). The serum IL-16 levels in the first-episode group (F = 1.18, P < 0.001) and the recurrence group (F = 0.83, P < 0.001) were significantly higher than in the control group, and there was no significant difference between the first-episode group and the recurrence group (F = 1.65, P = 0.61). Serum IL-1β was negatively correlated with the general psychopathological score (GPS) of PANSS (R=-0.353, P = 0.026). In the recurrence group, serum IL-16 was positively correlated with the negative score (NEG) of the PANSS scale (R = 0.335, P = 0.035) and negatively correlated with the composite score (COM) (R=-0.329, P = 0.038). In the study, IL-16 levels were an independent variable of the onset of schizophrenia both in the first-episode (OR = 1.034, P = 0.002) and recurrence groups (OR = 1.049, P = 0.003). ROC curve analysis showed that the areas under IL-16(FEG) and IL-16(REG) curves were 0.883 (95%CI:0.794-0.942) and 0.887 (95%CI:0.801-0.950).

CONCLUSIONS

Serum IL-1β and IL-16 levels were different between patients with schizophrenia and healthy people. Serum IL-1β levels in first-episode schizophrenia and serum IL-16 levels in relapsing schizophrenia were correlated with the parts of psychiatric symptoms. The IL-16 level may be an independent factor associating with the onset of schizophrenia.

Different measures for auditory hallucinations in populations with psychosis. The Validation of the Spanish versions of the Auditory Vocal Hallucination Rating Scale (AVHRS) and the Positive and Useful Voices Inquiry (PUVI)

INTRODUCTION

An updated summary of the most used instruments assessing auditory hallucinations in population with psychosis, allows us to underline the scarceness and need of Spanish versions of important instruments. The aim of the study is to examine the psychometric characteristics of two different and complementary instruments for assessing auditory hallucinations, the Spanish version of the Auditory Vocal Hallucination Scale (AVHRS) and the Spanish version of the Positive and Useful Voices Inquiry (PUVI).

MATERIALS AND METHODS

A sample of 68 patients from four different centres, with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder presenting with auditory hallucinations were included. Apart from the AVHRS and the PUVI, the Psychotic Symptom Rating Scales-Auditory Hallucinations subscale (PSYRATS-AH) and the Positive and Negative Syndrome Scale (PANSS) were also administered to all patients, plus an acceptability questionnaire.

RESULTS

The Spanish version of the AVHRS showed a good internal consistency, a moderate to high inter-rater reliability, a medium to moderate test-retest reliability, and a good convergent and discriminant validity. The Spanish version of the PUVI showed a good internal consistency and a heterogeneous, but in general moderate, test-retest reliability.

CONCLUSIONS

The Spanish versions of the AVHRS and the PUVI have good psychometric properties and are well accepted among patients.

Different measures for auditory hallucinations in populations with psychosis. The Validation of the Spanish versions of the Auditory Vocal Hallucination Rating Scale (AVHRS) and the Positive and Useful Voices Inquiry (PUVI)

INTRODUCTION

An updated summary of the most used instruments assessing auditory hallucinations in population with psychosis, allows us to underline the scarceness and need of Spanish versions of important instruments. The aim of the study is to examine the psychometric characteristics of two different and complementary instruments for assessing auditory hallucinations, the Spanish version of the Auditory Vocal Hallucination Scale (AVHRS) and the Spanish version of the Positive and Useful Voices Inquiry (PUVI).

MATERIALS AND METHODS

A sample of 68 patients from four different centres, with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder presenting with auditory hallucinations were included. Apart from the AVHRS and the PUVI, the Psychotic Symptom Rating Scales-Auditory Hallucinations subscale (PSYRATS-AH) and the Positive and Negative Syndrome Scale (PANSS) were also administered to all patients, plus an acceptability questionnaire.

RESULTS

The Spanish version of the AVHRS showed a good internal consistency, a moderate to high inter-rater reliability, a medium to moderate test-retest reliability, and a good convergent and discriminant validity. The Spanish version of the PUVI showed a good internal consistency and a heterogeneous, but in general moderate, test-retest reliability.

CONCLUSIONS

The Spanish versions of the AVHRS and the PUVI have good psychometric properties and are well accepted among patients.

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.

Peripheral Biomarkers for First-Episode Psychosis-Opportunities from the Neuroinflammatory Hypothesis of Schizophrenia

OBJECTIVE

Schizophrenia is a disabling disorder of unknown aetiology, lacking definite diagnostic method and cure. A reliable biological marker of schizophrenia is highly demanded, for which traceable immune mediators in blood could be promising candidates. We aimed to gather the best findings of neuroinflammatory markers for first-episode psychosis (FEP).

METHODS

We performed an extensive narrative review of online literature on inflammation-related markers found in human FEP patients only.

RESULTS

Changes to cytokine levels have been increasingly reported in schizophrenia. The peripheral levels of IL-1 (or its receptor antagonist), soluble IL-2 receptor, IL-4, IL-6, IL-8, and TNF-α have been frequently reported as increased in FEP, in a suggestive continuum from high-risk stages for psychosis. Microglia and astrocytes establish the link between this immune signalling and the synthesis of noxious tryptophan catabolism products, that cause structural damage and directly hamper normal neurotransmission. Amongst these, only 3-hydroxykynurenine has been consistently described in the blood of FEP patients.

CONCLUSION

Peripheral molecules stemming from brain inflammation might provide insightful biomarkers of schizophrenia, as early as FEP or even prodromal phases, although more time- and clinically-adjusted studies are essential for their validation.

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.

Elevated C-reactive protein as a predictor of a random one-year clinical course in the first ten years of schizophrenia

We investigate whether C-reactive protein (CRP) levels could predict the clinical course of patients with schizophrenia in a prospective study of 50 stable outpatients during a random 1-year period within the first 10 years of illness. Positive, negative, depressive, and cognitive symptoms were evaluated. Patients with low-grade inflammation (CRP = 3-10 mg/L; 28%) at baseline showed significant worsening of PANSS-positive and general psychopathology at 1-year follow-up compared with those with CRP ≤ 3 mg/L. Elevated CRP may be a biomarker of poor 1-year clinical course in patients with schizophrenia.

Translational research in psychiatry: The Research Domain Criteria Project (RDoC)

Despite the consensus achieved in the homogenization of clinical criteria by categorical psychiatric classification systems (DEM and CIE), they are criticized for a lack of validity and inability to guide clinical treatment and research. In this review article we introduce the Research Domain Criteria (RDoC) framework as an alternative framework for translational research in psychiatry. The RDOC framework systematizes both research targets and methodology for research in psychiatry. RDoC is based on a catalogue of neurobiological and neurocognitive evidence of behaviour, and conceives psychopathology as the phenotypic expression of alterations of functional domains that are classified into 5psychobiological systems. The RdoC framework also proposes that domains must be validated with evidence in 7levels of analysis: genes, molecules, cells, nerve circuits, physiology, behaviour and self-reports. As opposed to categorical systems focused on diagnosis, RDoC focuses on the study of psychopathology as a correlate of detectable functional, biological and behavioural disruption of normal processes. In order to build a useful psychiatric nosology for guiding clinical interventions, the RDoC research framework links the neurobiological basis of mental processes with phenotypical manifestations. Although the RDoC findings have not yet been articulated into a specific model for guiding clinical practice, they provide a useful transition system for creating clinical, basic and epidemiological research hypotheses.

Can interleukin-2 and interleukin-1β be specific biomarkers of negative symptoms in schizophrenia?

INTRODUCTION

Evidence suggests the existence of cytokine disturbances in patients with schizophrenia but their association with psychopathology is still unclear. The aim of the current study was to determine if pro-inflammatory cytokine levels (tumor necrosis factor-α, interleukin (IL)-6, IL-2, IL-1β, IL-1RA) are increased in stable outpatients compared with healthy subjects, and to analyze if they could be specific biomarkers of clinical dimensions in schizophrenia.

METHODS

We studied 73 stable outpatients with schizophrenia in their first 10 years of illness and 73 age- and sex-matched healthy controls. An accurate assessment of clinical dimensions (positive, negative, depressive, cognitive) was performed in patients.

RESULTS

Only IL-6 levels were significantly increased in patients after controlling for body mass index, waist circumference, smoking, and psychopharmacological treatment, compared with healthy subjects. After adjusting for several confounders, multiple linear regression models identified that Positive and Negative Syndrome Scale negative symptoms, general psychopathology, and global severity are predicted by IL-1β concentrations, while motivation and pleasure domain of Clinical Assessment Interview for Negative Symptoms and Personal and Social Performance global functioning scores are predicted by IL-2 levels. Cognitive performance, positive, and depressive symptom severity did not correlate with any cytokine.

CONCLUSIONS

Our findings suggested that IL-6 concentrations are elevated in stable patients with schizophrenia. Whereas IL-2 specifically marks severity of the motivation and pleasure domain of negative symptoms, IL-1β is not specific to this dimension as it also predicts severity of general and global symptomatology.

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.

Short overview on metabolomic approach and redox changes in psychiatric disorders

Schizophrenia, depression and posttraumatic stress disorder (PTSD) are severe mental disorders and complicated diagnostic entities, due to their phenotypic, biological and genetic heterogeneity, unknown etiology, and poorly understood alterations in biological pathways and biological mechanisms. Disturbed homeostasis between overproduction of oxidant species, overcoming redox regulation and a lack of cellular antioxidant defenses, resulting in free radical-mediated pathology and subsequent neurotoxicity contributes to development of depression, schizophrenia and PTSD, their heterogeneous clinical presentation and resistance to treatment. Metabolomics is a discipline that combines different strategies with the aim to extract, detect, identify and quantify all metabolites that are present in a biological sample and might provide mechanistic insights into the etiology of various psychiatric disorders. Therefore, oxidative stress research combined with metabolomics might offer a novel approach in dissecting psychiatric disorders, since these data-driven but not necessarily hypothesis-driven methods might identify new targets, molecules and pathways responsible for development of schizophrenia, depression or PTSD. Findings from the oxidative research in psychiatry together with metabolomics data might facilitate development of specific and validated prognostic, therapeutic and clinical biomarkers. These methods might reveal bio-signatures of individual patients, leading to individualized treatment approach. In reviewing findings related to oxidative stress and metabolomics in selected psychiatric disorders, we have highlighted how these novel approaches might make a unique contribution to deeper understanding of psychopathological alterations underlying schizophrenia, depression and PTSD.