The relationship between psychopathology and cognitive functions with cytokines in clinically stable patients with schizophrenia

Comparison of olfactory function, cognitive function and serum tumor necrosis factor-α between bipolar and schizophrenic patients in the remission stage

OBJECTIVES

Olfactory function, serum tumor necrosis factor-α (TNF-α) and cognitive function were compared between bipolar disorder (BD) and schizophrenia (SP) patients in the remission stage combined with correlation analysis, with the aim of identifying new indicators for the auxiliary diagnosis of these psychiatric illnesses.

METHODS

A total of 46 euthymic BD patients, 42 clinically stable SP patients and 42 healthy controls (HC) were included in this study. Olfactory sensitivity (OS) and olfactory identification (OI) were assessed using Sniffin' Sticks test, and serum TNF-α levels were measured by ELISA. Clinical symptoms were evaluated with the Hamilton Rating Scale for Depression, Young Mania Rating Scale, Hamilton anxiety scale, and the Positive and Negative Syndrome Scale (PANSS). Social function was evaluated with the Global Assessment Function (GAF) scale. Cognitive function was evaluated using the Trail Making Test-A (TMT-A) and Digit Cancellation Test (DCT).

RESULTS

OI and cognitive function scores and serum TNF-α levels were significantly lower in the BD and SP patients compared with the HC participants. There was no significant difference between the BD and SP groups, and there were no significant differences in OS among the three groups. OI score was positively correlated with years of education in both the BD and SP groups. OI score in the SP group was negatively correlated with age and PANSS score, and positively correlated with GAF score. In the BD group, OS was positively correlated with DCT II and DCT III. In the SP group, OS and OI scores were positively correlated with DCT III, and negatively correlated with TMT-A time. Furthermore, there was a positive correlation between TNF-α and DCT II in the BD group. There was no significant linear correlation between olfactory function and TNF-α in the BD or SP group.

CONCLUSION

OI may be a trait marker for BD and SP. Some cognitive functions may be correlated not only with TNF-α in BD patients in remission, but also with olfactory function in BD and SP patients in remission.

The relationship between inflammatory biomarkers and cognitive dysfunction in patients with schizophrenia: A systematic review and meta-analysis

BACKGROUND

Schizophrenia is a complex psychiatric disorder that includes positive and negative symptoms but also debilitating cognitive deficits. Current pharmacological interventions do not target these deficits. Recent evidence suggests a connection between some inflammatory markers (including C-reactive protein) and cognitive impairment, but did not address other inflammatory markers. In the current study, we try to fill the gap by focusing on the association of Interleukin-6 (IL-6), IL-1β, Tumor Necrosis Factor-α and CRP with cognitive dysfunction.

METHODS

PUBMED and Web of Science databases were searched for all studies published until July 2022. A total of 25 studies were included in an analysis of the association between cognitive performance and variation in IL-6, IL-1β, TNF-α and CRP.

RESULTS

A total of 2398 patients were included in this study. Meta-analyses results showed a significant inverse relationship between performance in five cognitive domains (attention-processing speed, executive function, working memory, verbal and visual learning and memory) and systemic IL-6, IL-1β, TNF-α and CRP plasma levels in patients with schizophrenia. The meta-analyses results showed a significant decline in the cognitive performances with the evaluated inflammatory markers with effect sizes ranging from -0.136 to -0.181 for IL-6, -0.188 to -0.38 for TNF-α -0.372 to -0.476 for IL-1β and - 0.168 to -0.311 for CRP.

CONCLUSION

Findings from the current study shows that cognitive deficits are reflective of elevated proinflammatory biomarkers (IL-6, IL-1β, TNF-α and CRP) levels. The results obtained indicate relatedness between inflammation and cognitive decline in patients with schizophrenia. Understanding the underlying pathways between them could have a significant impact on the disease progression and quality of life in schizophrenia patients.

Knowledge Graphs for Indication Expansion: An Explainable Target-Disease Prediction Method

Indication expansion aims to find new indications for existing targets in order to accelerate the process of launching a new drug for a disease on the market. The rapid increase in data types and data sources for computational drug discovery has fostered the use of semantic knowledge graphs (KGs) for indication expansion through target centric approaches, or in other words, target repositioning. Previously, we developed a novel method to construct a KG for indication expansion studies, with the aim of finding and justifying alternative indications for a target gene of interest. In contrast to other KGs, ours combines human-curated full-text literature and gene expression data from biomedical databases to encode relationships between genes, diseases, and tissues. Here, we assessed the suitability of our KG for explainable target-disease link prediction using a glass-box approach. To evaluate the predictive power of our KG, we applied shortest path with tissue information- and embedding-based prediction methods to a graph constructed with information published before or during 2010. We also obtained random baselines by applying the shortest path predictive methods to KGs with randomly shuffled node labels. Then, we evaluated the accuracy of the top predictions using gene-disease links reported after 2010. In addition, we investigated the contribution of the KG’s tissue expression entity to the prediction performance. Our experiments showed that shortest path-based methods significantly outperform the random baselines and embedding-based methods outperform the shortest path predictions. Importantly, removing the tissue expression entity from the KG severely impacts the quality of the predictions, especially those produced by the embedding approaches. Finally, since the interpretability of the predictions is crucial in indication expansion, we highlight the advantages of our glass-box model through the examination of example candidate target-disease predictions.

Cytokine Level and Symptoms of Schizophrenia

BACKGROUND: The study was intended to find one of the cytokines, that is, tumor necrosis factor (TNF)-alpha correlation with PANSS scores of people with schizophrenia (PwS) and their differences compared to the healthy people of Malayan- Mongoloid Race. AIM: The aim of this study was providing a profile of TNF-alpha level in PwS of Malayan-Mongoloid race and its correlation with positive and negative symptoms in schizophrenia. METHODS: It was conducted using cross-sectional and following sampling methods, with inclusion and exclusion criteria set for the PwS and control groups. RESULTS: The result was no correlation between TNF-alpha levels with PANSS scores on PwS (p > 0.005), with very weak correlation and positive correlation direction, and there were differences in TNF-alpha levels.between PwS and control groups. CONCLUSION: It can be concluded that the higher levels of TNF-alpha would impact on the severity symptoms experienced by PwS.

Role of Tumor Necrosis Factor-Alpha in Schizophrenia and Cognitive Impairment

Background: Neuroinflammation and excitotoxicity play a key role as triggers and support for neurodegenerative processes, increase levels of TNF-α have been found in schizophrenic patients. Improved inflammatory processes have been demonstrated in acute and chronic schizophrenia. In schizophrenia is characterized by a collection of core symptoms that trigger individuals experiencing several cognitive disorders. Objective: To investigate the relationship of serum TNF-α levels to impaired cognitive function in schizophrenic patients in Medan, Indonesia. Method: This research is cross sectional analytical correlative study involving 40 male schizophrenic patients at Prof. Dr. M. Ildrem Mental Hospital through July to September 2019 that fulfilled our inclusion and exclusion criteria. Serum TNF-α levels were analyzed using Quantikine HS Human TNF-α Assay with a minimum detection limit of  0.1062 pg/ml while in the other hand, cognitive function test was carried out by using the Mini Mental State Examination. Results: Serum TNF-α levels with a mean of 25.1216 with a standard deviation of 1.7629. There is a positive correlation with moderate correlation (r = 0.4 - <0.6) on cognitive function with the strength of correlation r = 0.434 Conclusion: We found that there is a link between serum TNF-α level and cognitive function as assessed with the Mini-Mental State Examination (MMSE).

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.

[Does alcohol influence the cognitive functions of schizophrenic patients?]

AIM

To establish an effect of alcohol dependence on the cognitive functions of patients with schizophrenia.

MATERIAL AND METHODS

One hundred patients with paranoid schizophrenia were examined. Half of them had a co-occurring diagnosis of alcohol dependence syndrome. Memory, attention, thinking were studied. Comparisons were made between groups, depending on the presence of the addictive disorder.

RESULTS

Attention and short-term memory are at the low border of normal values in both groups. No significant between-group differences were found. In Benton test, errors characteristic of schizophrenia were more frequent in the main group. 'Organic' errors were prevalent in the control group. Mild thinking disorders of organic type were significantly more frequent in the main group.

CONCLUSION

Co-occurring alcohol dependence does not significantly influence intelligence but significant organic stigmas contribute to the structure of the cognitive profile of patients. The prevalence of organic disturbances in the structure of thinking in patients with co-occurring alcohol abuse was revealed. The best indicators of attention were demonstrated by patients with attack-like schizophrenia without substance abuse. This suggests that the influence of the alcohol factor differs in continuous and attack-like progressive schizophrenia.

Relationship of Interferon-γ to Cognitive Function in Midlife Women with Schizophrenia

Recent literature suggests that schizophrenia is linked to an abnormal response of the immune system. Interferon-γ is a cytokine that acts as a mediator between immune stimulation and the kynurenine pathway and may be related to cognitive abilities. The objectives of the present study are to determine if serum cytokines are correlated with cognitive function differently in patients with schizophrenia compared to controls. Fourteen midlife (30-70 year-old) females with DSM-IV diagnosis of schizophrenia or schizoaffective disorder and 13 midlife control females were analyzed. Cytokines were collected from serum blood draws and analyzed at the Cytokine Core Lab at the University of Maryland, Baltimore. The RBANS, HVLT-R, and UPSA were performed to measure cognition and social performance. The results demonstrate a non-significant difference between interferon-γ levels in women with schizophrenia compared to controls, but this cytokine appears to correlate to cognitive abilities differently in these groups. There were several significant negative correlations between interferon-γ and cognition in midlife patients with schizophrenia, but only one in the midlife control group. The negative correlations between interferon-γ and cognition in patients with schizophrenia suggest the hypothesis that inflammation and the kynurenine pathway have important roles in this disorder.