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Reale M, Costantini E, Greig NH. Cytokine Imbalance in Schizophrenia. From Research to Clinic: Potential Implications for Treatment. Front Psychiatry 2021; 12:536257. [PMID: 33746786 PMCID: PMC7973221 DOI: 10.3389/fpsyt.2021.536257] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 01/18/2021] [Indexed: 12/13/2022] Open
Abstract
Cytokines are one of the most important components of the immune system. They orchestrate the brain's response to infectious and other exogenous insults and are crucial mediators of the cross-talk between the nervous and immune systems. Epidemiological studies have demonstrated that severe infections and autoimmune disorders, in addition to genetic predisposition, are risk factors for schizophrenia. Furthermore, maternal infection during pregnancy appears to increase the risk of schizophrenia, and proinflammatory cytokines may be negatively involved in the neurodevelopmental process. A cytokine imbalance has been described in the blood and cerebrospinal fluid of schizophrenia patients, particularly in the T helper type 1 [Th1] and type 2 [Th2] cytokines, albeit the results of such studies appear to be contradictory. Chronic stress, likewise, appears to contribute to a lasting proinflammatory state and likely also promotes the disorder. The aim of this mini-review is to investigate the roles of different cytokines in the pathophysiology of schizophrenia and define how cytokines may represent key molecular targets to regulate for the prevention and treatment of schizophrenia. How current antipsychotic drugs impact cytokine networks is also evaluated. In this context, we propose to change the focus of schizophrenia from a traditionally defined brain disorder, to one that is substantially impacted by the periphery and immune system.
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Affiliation(s)
- Marcella Reale
- Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Erica Costantini
- Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Nigel H Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
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Jemli A, Eshili A, Trifa F, Mechri A, Zaafrane F, Gaha L, Juckel G, Tensaout BBHJ. Association of the IFN-γ (+874A/T) Genetic Polymorphism with Paranoid Schizophrenia in Tunisian Population. Immunol Invest 2016; 46:159-171. [PMID: 27819519 DOI: 10.1080/08820139.2016.1237523] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Since growing evidence suggests a significant role of chronic low-grade inflammation in the physiopathology of schizophrenia, we have hypothesized that functional genetic variant of the IFN gamma (IFN-γ; +874A/T; rs2430561) gene may be involved in the predisposition to schizophrenia. This research is based on a case-control study which aims to identify whether polymorphism of the IFN-γ gene is a risk factor for the development of schizophrenia. The RFLP-PCR genotyping of the IFN-γ gene was conducted on a Tunisian population composed of 218 patients and 162 controls. The IFN-γ (+874A/T) polymorphism analysis showed higher frequencies of minor homozygous genotype (TT) and allele (T) in all patients compared with controls (11.5 vs. 4.9%; p = 0.03, OR = 2.64 and 30.7 vs. 24.1%, p = 0.04, OR = 1.4, respectively). This correlation was confirmed for male but not for female patients. Also, the T allele was significantly more common among patients with paranoid schizophrenia when compared with controls (25.8 vs. 4.9%, p = 0.0001; OR = 6.7). Using the binary regression analysis to eliminate confounding factors as age and sex, only this last association remained significant (p = 0.03; OR = 1.76, CI = 1.05-2.93). In conclusion, our results showed a significant association between +874A/T polymorphism of IFN-γ and paranoid schizophrenia, suggesting that this single nucleotide polymorphism (SNP) or another at proximity could predispose to paranoid schizophrenia. Since the minor allele of this polymorphism was correlated with an increased expression of their product, our study validates the hypothesis of excessive pro-inflammatory cytokine in the physiopathology of paranoid schizophrenia.
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Affiliation(s)
- Achraf Jemli
- a Laboratory of Genetics, Biodiversity and Bioresource Valorization, Higher Institute of Biotechnology of Monastir , University of Monastir , Monastir , Tunisia
| | - Awatef Eshili
- a Laboratory of Genetics, Biodiversity and Bioresource Valorization, Higher Institute of Biotechnology of Monastir , University of Monastir , Monastir , Tunisia
| | - Fatma Trifa
- b Department of Biostatistics , Higher Institute of Biotechnology of Monastir, University of Monastir , Monastir , Tunisia.,c Laboratory of Biomass Valorization and Production of Eucaryotic Proteins, Center of Biotechnology of Sfax , Sfax , Tunisia
| | - Anouar Mechri
- d Department of Psychiatry and Vulnerability to Psychoses Laboratory - CHU Monastir , University of Monastir , Monastir , Tunisia
| | - Ferid Zaafrane
- d Department of Psychiatry and Vulnerability to Psychoses Laboratory - CHU Monastir , University of Monastir , Monastir , Tunisia
| | - Lotfi Gaha
- d Department of Psychiatry and Vulnerability to Psychoses Laboratory - CHU Monastir , University of Monastir , Monastir , Tunisia
| | - George Juckel
- e Department of Psychiatry and Psychotherapy , Ruhr University, Bochum LWL University Hospital Bochum , Bochum , Germany
| | - Besma Bel Hadj Jrad Tensaout
- a Laboratory of Genetics, Biodiversity and Bioresource Valorization, Higher Institute of Biotechnology of Monastir , University of Monastir , Monastir , Tunisia
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Guo J, Liu C, Wang Y, Feng B, Zhang X. Role of T helper lymphokines in the immune-inflammatory pathophysiology of schizophrenia: Systematic review and meta-analysis. Nord J Psychiatry 2015; 69:364-72. [PMID: 25529895 DOI: 10.3109/08039488.2014.986761] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Schizophrenia is highly complex multifactorial psychiatric disorder with poorly defined etiopathophysiology, which also has manifestations in the immune system. AIMS The aim of this review is to meta-analyze the available evidence regarding the role of immune activation indicated by the T helper cells in order to evaluate etiopathophysiological links between the immune system and schizophrenia. METHODS A literature search was performed in multiple electronic databases for relevant research papers published between 1990 and May 2014. Meta-analyses were conducted under both random- (REM) and fixed-effect models (FEM) by calculating weighted mean differences with 95% confidence intervals. Heterogeneity was assessed with the I(2) index. RESULTS Twenty-one studies were selected after observing inclusion and exclusion criteria. In vitro interferon-gamma (INF-γ) and interleukin (IL)-2 production was significantly lower in the schizophrenic patients compared with non-schizophrenic control individuals under both FEM and REM. Serum levels of IL-2 and serum/in vitro IL-4 were not significantly different in both groups under both FEM and REM. Overall Th1:Th2 ratio (INF-γ:IL-4 and IL-2:IL-4) in the serum samples was significantly deflected towards Th2 under both models in the serum samples (- 0.33 [- 0.59 to - 0.06]; P < 0.03, FEM and - 2.44 [- 4.27 to - 0.60]; P < 0.009, REM) but in vitro production Th1:Th2 ratio (INF-γ:IL-4 and IL-2:IL-4) was deflected towards Th1 under both the models (1.11 [0.45-1.78]; P < 0.002, FEM and 6.68 [0.72-12.64]; P < 0.03, REM). CONCLUSIONS Whereas the Th1:Th2 ratio in the serum samples deflected towards T2, in vitro Th1:Th2 ratio favored Th1 when the individual study data were meta-analyzed.
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Affiliation(s)
- Jing Guo
- Jing Guo, M.D., Clinical Laboratory, The 261st Hospital of The People's Liberation Army , Beijing , China
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Vakalopoulos C. The effect of deficient muscarinic signaling on commonly reported biochemical effects in schizophrenia and convergence with genetic susceptibility loci in explaining symptom dimensions of psychosis. Front Pharmacol 2014; 5:277. [PMID: 25566074 PMCID: PMC4266038 DOI: 10.3389/fphar.2014.00277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 11/27/2014] [Indexed: 11/13/2022] Open
Abstract
With the advent of DSM 5 criticism has generally centered on a lack of biological validity of the diagnostic criteria. Part of the problem in describing a nosology of psychosis is the tacit assumption of multiple genetic causes each with an incremental loading on the clinical picture that fails to differentiate a clear underlying pathophysiology of high impact. The aim of this paper is to consolidate a primary theory of deficient muscarinic signaling underlying key clinical features of schizophrenia and its regulation by several important genetic associations including neuregulin, DISC and dysbindin. Secondary reductions in markers for GABAergic function and changes in the levels of interneuron calcium binding proteins parvalbumin and calbindin can be attributed to dysfunctional muscarinic transduction. A parallel association exists for cytokine production. The convergent pathway hypothesis is likewise used to model dopaminergic and glutamatergic theories of schizophrenia. The negative symptom dimension is correlated with dysfunction of Akt and ERK transduction, a major point of convergence. The present paradigm predicts the importance of a recent finding of a deletion in a copy number variant of PLCB1 and its potential use if replicated, as one of the first testable biological markers differentiating schizophrenia from bipolar disorder and further subtyping of schizophrenia into deficit and non-deficit. Potential limitations of PLCB1 as a prospective marker are also discussed.
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Abstract
OBJECTIVES The purpose of this review is to analyse, sum up and discuss the available literature on the role of inflammation and inflammatory cytokines in the pathogenesis of schizophrenia. METHODS An electronic literature search of peer-reviewed English language articles using Pubmed was undertaken. These articles together with those published by us provided the background for the present review. RESULTS An overview of the available literature on this issue clearly demonstrated the alterations in mRNA and protein expression levels of several proinflammatory and chemotactic cytokines in patients with schizophrenia. Importantly, some of these changes are genetically determined. It was noteworthy that, depending on the study population, some variations of the data obtained are detected. CONCLUSIONS Altered inflammatory cytokine production, both genetically and environmentally determined, is implicated in schizophrenia and contributes to disease-associated low-grade systemic inflammation. Proinflammatory and chemotactic cytokines and their receptors may represent additional therapeutic targets for treatment of schizophrenia.
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Asevedo E, Rizzo LB, Gadelha A, Mansur RB, Ota VK, Berberian AA, Scarpato BS, Teixeira AL, Bressan RA, Brietzke E. Peripheral interleukin-2 level is associated with negative symptoms and cognitive performance in schizophrenia. Physiol Behav 2014; 129:194-8. [PMID: 24576679 DOI: 10.1016/j.physbeh.2014.02.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/07/2013] [Accepted: 02/12/2014] [Indexed: 01/13/2023]
Abstract
Although several studies have pointed to a possible role of interleukin 2 (IL-2) in schizophrenia (SZ), association between IL-2 and the different groups of symptoms has not been explored. The objective of this study was to investigate a possible correlation of peripheral IL-2 levels with symptoms and cognitive performance in patients with SZ. In addition, we compared the plasma levels of IL-2 between patients with SZ and healthy controls. Twenty-nine chronically medicated outpatients with SZ according to DSM-IV were compared with twenty-six healthy controls. The patients were evaluated with the Positive and Negative Syndrome Scale (PANSS), the Calgary Depression Scale for Schizophrenia (CDSS), the Clinical Global Impression (CGI) and the Global Assessment of Functioning (GAF). All the participants had blood collected into EDTA tubes by venipuncture between 9:00 and 10:00AM. Plasma concentrations of IL-2 were determined by cytometric bead array. A computerized neuropsychological battery assessed verbal learning, verbal fluency, working memory, set shifting, executive function, inhibition and intelligence. Patients with SZ had lower levels of IL-2 than healthy controls (p<0.001). In the SZ group, IL-2 levels were positively correlated with scores in the digit span test (rho=0.416, P=0.025) and intelligence (rho=0.464, P=0.011). We also found a negative correlation between IL-2 and total score in the negative subscale of PANSS (rho=-0.447, p=0.015). Our findings suggest that IL-2 may be involved in the mechanisms related to cognitive deterioration and negative symptomatology in schizophrenia.
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Affiliation(s)
- Elson Asevedo
- Schizophrenia Program (PROESQ), Department of Psychiatry, Federal University of São Paulo, Rua Machado Bittencourt, 222, São Paulo, SP, CEP 04044-000, Brazil; Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Lucas B Rizzo
- Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Ary Gadelha
- Schizophrenia Program (PROESQ), Department of Psychiatry, Federal University of São Paulo, Rua Machado Bittencourt, 222, São Paulo, SP, CEP 04044-000, Brazil; Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Rodrigo B Mansur
- Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Vanessa K Ota
- Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Arthur A Berberian
- Schizophrenia Program (PROESQ), Department of Psychiatry, Federal University of São Paulo, Rua Machado Bittencourt, 222, São Paulo, SP, CEP 04044-000, Brazil; Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Bruno S Scarpato
- Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Antônio L Teixeira
- Translational Psychoneuroimmunology Group, Federal University of Minas Gerais, Avenida Antonio Carlos, 6627, Pampulha, Belo Horizonte MG, CEP 31270-901, Brazil.
| | - Rodrigo A Bressan
- Schizophrenia Program (PROESQ), Department of Psychiatry, Federal University of São Paulo, Rua Machado Bittencourt, 222, São Paulo, SP, CEP 04044-000, Brazil; Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
| | - Elisa Brietzke
- Interdisciplinary Laboratory of Clinical Neurosciences (LINC), Department of Psychiatry, Federal University of São Paulo, Rua Pedro de Toledo, 669, Edifício de Pesquisas II, third floor, São Paulo SP, CEP 04039-032, Brazil.
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Na KS, Jung HY, Kim YK. The role of pro-inflammatory cytokines in the neuroinflammation and neurogenesis of schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2014; 48:277-86. [PMID: 23123365 DOI: 10.1016/j.pnpbp.2012.10.022] [Citation(s) in RCA: 284] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 10/11/2012] [Accepted: 10/26/2012] [Indexed: 12/22/2022]
Abstract
Schizophrenia is a serious mental illness with chronic symptoms and significant impairment in psychosocial functioning. Although novel antipsychotics have been developed, the negative and cognitive symptoms of schizophrenia are still unresponsive to pharmacotherapy. The high level of social impairment and a chronic deteriorating course suggest that schizophrenia likely has neurodegenerative characteristics. Inflammatory markers such as pro-inflammatory cytokines are well-known etiological factors for psychiatric disorders, including schizophrenia. Inflammation in the central nervous system is closely related to neurodegeneration. In addition to pro-inflammatory cytokines, microglia also play an important role in the inflammatory process in the CNS. Uncontrolled activity of pro-inflammatory cytokines and microglia can induce schizophrenia in tandem with genetic vulnerability and glutamatergic neurotransmitters. Several studies have investigated the possible effects of antipsychotics on inflammation and neurogenesis. Additionally, anti-inflammatory adjuvant therapy has been under investigation as a treatment option for schizophrenia. Further studies should consider the confounding effects of systemic factors such as metabolic syndrome and smoking. In addition, the unique mechanisms by which pro-inflammatory cytokines are involved in the etiopathology of schizophrenia should be investigated. In this article, we aimed to review (1) major findings regarding neuroinflammation and pro-inflammatory cytokine alterations in schizophrenia, (2) interactions between neuroinflammation and neurogenesis as possible neural substrates for schizophrenia, and (3) novel pharmacological approaches.
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Affiliation(s)
- Kyoung-Sae Na
- Department of Psychiatry, Soonchunhyang University Bucheon Hospital, Bucheon, Republic of Korea
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Abstract
Recent research has overcome the old paradigms of the brain as an immunologically privileged organ, and of the exclusive role of neurotransmitters and neuropeptides as signal transducers in the central nervous system. Growing evidence suggests that the signal proteins of the immune system - the cytokines - are also involved in modulation of behavior and induction of psychiatric symptoms. This article gives an overview on the nature of cytokines and the proposed mechanisms of immune-to-brain interaction. The role of cytokines in psychiatric symptoms, syndromes, and disorders like sickness behavior, major depression, and schizophrenia are discussed together with recent immunogenetic findings.
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Affiliation(s)
- Markus J Schwarz
- Psychiatric Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
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Mansur RB, Zugman A, Asevedo EDM, da Cunha GR, Bressan RA, Brietzke E. Cytokines in schizophrenia: possible role of anti-inflammatory medications in clinical and preclinical stages. Psychiatry Clin Neurosci 2012; 66:247-60. [PMID: 22624729 DOI: 10.1111/j.1440-1819.2012.02354.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AIMS In this paper, we review the literature on the efficacy of anti-inflammatory agents as neuroprotectors in clinical and preclinical stages of schizophrenia. METHOD A synthetic and integrative approach was applied to review studies stemming from epidemiology, phenomenology, cognition, genetics and neuroimaging data. We provide conclusions and future directions of research on early-onset schizophrenia. RESULTS Abnormal inflammatory activation has been demonstrated in schizophrenia. Increases or imbalances in cytokines before birth or during childhood may impact neurodevelopment and produce vulnerability to schizophrenia. The specificity of inflammatory abnormalities in psychiatric disorders is controversial. Similar increases in pro-inflammatory cytokines have been described in other disorders, especially mood and anxiety disorders. One of the most important challenges at this point is the understanding of neurobiological correlates of prodromal stages of schizophrenia. CONCLUSION Although future research should investigate the exact role of different cytokines in pathophysiology of schizophrenia, these mediators emerge as promising molecular targets to its prevention and treatment.
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Affiliation(s)
- Rodrigo Barbachan Mansur
- Program for Recognition and Intervention in Individuals in at Risk Mental States, Department of Psychiatry, Universidade Federal de São Paulo, São Paulo, Brazil
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Affiliation(s)
- Michael R Irwin
- Semel Institute for Neuroscience, University of California, Los Angeles, CA, USA.
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Singh B, Bera NK, Nayak CR, Chaudhuri TK. Immunomodulation in schizophrenia: A study among the Indian schizophrenia patients of Siliguri, West Bengal. Asian J Psychiatr 2011; 4:277-83. [PMID: 23051162 DOI: 10.1016/j.ajp.2011.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 07/15/2011] [Accepted: 08/07/2011] [Indexed: 10/16/2022]
Abstract
Authors investigated the circumstantial evidence for autoimmunity in schizophrenia patients of Siliguri by considering the immune parameters like HLA Class I genes, IL-2 and IL6 and T cell subsets. Low resolution PCR-SSP method was applied for typing the HLA genes. Serum levels of IL-2 and IL-6 were measured by ELISA method. The CD4+ and CD8+ subset count were done using flow cytometry. A significant increase in HLA A*03 gene was observed in patients along with the significant decrease of HLA-A*31 and HLA-B*51. Both IL-2 and IL-6 were found to have decreased levels in the patients. Although the mean percentage of CD4+ and CD8+ cells was higher in patients but not significantly higher than controls. These cumulative preliminary findings are suggestive of alterations in the immune system of schizophrenia patients of this region.
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Affiliation(s)
- Bisu Singh
- Cellular Immunology Laboratory, Department of Zoology, University of North Bengal, Siliguri 734 430, West Bengal, India
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Sasayama D, Hori H, Teraishi T, Hattori K, Ota M, Iijima Y, Tatsumi M, Higuchi T, Amano N, Kunugi H. Possible association between interleukin-1β gene and schizophrenia in a Japanese population. Behav Brain Funct 2011; 7:35. [PMID: 21843369 PMCID: PMC3168401 DOI: 10.1186/1744-9081-7-35] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 08/16/2011] [Indexed: 11/28/2022] Open
Abstract
Background Several lines of evidence have implicated the pro-inflammatory cytokine interleukin-1beta (IL-1β) in the etiology of schizophrenia. Although a number of genetic association studies have been reported, very few have systematically examined gene-wide tagging polymorphisms. Methods A total of 533 patients with schizophrenia (302 males: mean age ± standard deviation 43.4 ± 13.0 years; 233 females; mean age 44.8 ± 15.3 years) and 1136 healthy controls (388 males: mean age 44.6 ± 17.3 years; 748 females; 46.3 ± 15.6 years) were recruited for this study. All subjects were biologically unrelated Japanese individuals. Five tagging polymorphisms of IL-1β gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were examined for association with schizophrenia. Results Significant difference in allele distribution was found between patients with schizophrenia and controls for rs1143633 (P = 0.0089). When the analysis was performed separately in each gender, significant difference between patients and controls in allele distribution of rs1143633 was observed in females (P = 0.0073). A trend towards association was also found between rs16944 and female patients with schizophrenia (P = 0.032). Conclusions The present study shows the first evidence that the IL-1β gene polymorphism rs1143633 is associated with schizophrenia susceptibility in a Japanese population. The results suggest the possibility that the influence of IL-1β gene variations on susceptibility to schizophrenia may be greater in females than in males. Findings of the present study provide further support for the role of IL-1β in the etiology of schizophrenia.
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Affiliation(s)
- Daimei Sasayama
- Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, 187-8502, Japan.
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Chan MK, Guest PC, Levin Y, Umrania Y, Schwarz E, Bahn S, Rahmoune H. Converging evidence of blood-based biomarkers for schizophrenia: an update. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 101:95-144. [PMID: 22050850 DOI: 10.1016/b978-0-12-387718-5.00005-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This chapter has carried out a review of the literature and combined this with the results of in-house studies to identify candidate blood-based biomarkers for schizophrenia and antipsychotic drug response. Literature searches retrieved 185 publications describing a total of 273 schizophrenia biomarkers identified in serum and/or plasma. Examination of seven in-house multicenter studies resulted in the identification of 137 serum/plasma biomarkers. Taken together, the findings suggested an ongoing immunological and inflammatory process in schizophrenia. This was accompanied by altered cortisol levels which suggested activated stress response and altered hypothalamic-pituitary-adrenal axis function in these patients. The authors conclude that such biomarkers may prove useful as additional parameters for characterizing specific immune and/or metabolic or hormonal subsystems in schizophrenia and might, therefore, facilitate the development of future patient stratification and personalized medicine strategies.
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Affiliation(s)
- Man K Chan
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
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Lee HY, Kim YK. Effect of TGF-β1 polymorphism on the susceptibility to schizophrenia and treatment response to atypical antipsychotic agent. Acta Neuropsychiatr 2010; 22:174-9. [PMID: 25385122 DOI: 10.1111/j.1601-5215.2009.00435.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
UNLABELLED Lee H-Y, Kim Y-K. Effect of TGF-β1 polymorphism on the susceptibility to schizophrenia and treatment response to atypical antipsychotic agent. OBJECTIVE Several studies have suggested that cytokine alterations could be related to the pathophysiology of schizophrenia. Transforming growth factor-beta1 (TGF-β1) is believed to be an important factor in regulation of inflammatory responses and to have anti-inflammatory effects. TGF-β1 also has trophic effects on dopaminergic neurons. We tested the hypothesis TGF-β1 is associated with the pathophysiology of schizophrenia. METHODS The polymorphisms at codon 10 (T869C) and codon 25 (G915C) of TGF-β1 were analysed in 99 schizophrenia patients and 130 normal controls. At baseline and after 8 weeks of treatment, clinical symptoms were evaluated on Positive and Negative Syndrome Scale (PANSS). RESULTS None of the subjects were polymorphic at codon 25. However, the C allele at codon 10 was more frequent in schizophrenia (p = 0.05). Although schizophrenia group showed a higher tendency of allele frequency in the subjects with C allele (p = 0.05), the allelic difference did not reach statistical significance after correction for multiple comparisons (p = 0.1). PANSS scores showed no significant correlation with genotypes. The genotype distribution was not significantly different between responders and non-responders. However, the C allele was more frequent among responders (p = 0.03). CONCLUSION These results suggest that the TGF-β1 polymorphism is associated with therapeutic response to antipsychotics. However, further studies with larger numbers of subjects are needed to confirm the effect of TGF-β1 in schizophrenia.
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Affiliation(s)
- Hwa-Young Lee
- 1Department of Psychiatry, College of Medicine, Korea University, Korea
| | - Yong-Ku Kim
- 1Department of Psychiatry, College of Medicine, Korea University, Korea
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Xu M, He L. Convergent evidence shows a positive association of interleukin-1 gene complex locus with susceptibility to schizophrenia in the Caucasian population. Schizophr Res 2010; 120:131-42. [PMID: 20347268 DOI: 10.1016/j.schres.2010.02.1031] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 02/07/2010] [Accepted: 02/09/2010] [Indexed: 01/08/2023]
Abstract
Recent genetic studies have revealed that the Interleukin-1 (IL1) gene complex (IL1 alpha, IL1 beta and IL1 receptor antagonist) is associated with schizophrenia, but contradictory findings have also been reported. We investigated the association of the IL1 gene complex locus and schizophrenia using meta-analytic techniques, covering all published data up to January 2010, to restrict to the most commonly reported 4 single nucleotide polymorphisms (SNP). We also explored potential sources of heterogeneity and to investigate whether ancestry and study design moderated any association. The combined allele-wise odds ratio (OR) for schizophrenia of the rs16944 (IL1B gene; T-511C) polymorphism was 0.86 (95% CI: 0.77to 0.96).When applying stratified analysis to this polymorphism, the pooled allele-wise OR was 0.88 (95% CI, 0.79 to 0.97) in 10 population-based studies and 0.85 (95% CI: 0.73 to 0.99) in Caucasian samples. In a stratified analysis of the rs1143634 (IL1B gene; T3953C) polymorphism, the pooled genotype-wise results in a dominant model were also statistically significant both in a population-based study subgroup with summary OR of 0.64 (95% CI: 0.41 to 0.99) and a Caucasian population subgroup with summary OR of 0.62 (95% CI: 0.40 to 0.97). Neither combined nor stratified analyses found any association of the rs1800587 (IL1A gene; T-889C) or rs1794068 (IL1RA Gene; IL1RN_86 bp; T/C) with schizophrenia susceptibility. Our study suggests the IL1B gene or the IL1 gene complex may play a moderate role in the etiology of schizophrenia in the Caucasian population.
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Affiliation(s)
- Mingqing Xu
- School of Public Health, Harvard University, Boston, MA 02115, USA.
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16
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Watanabe Y, Someya T, Nawa H. Cytokine hypothesis of schizophrenia pathogenesis: evidence from human studies and animal models. Psychiatry Clin Neurosci 2010; 64:217-30. [PMID: 20602722 DOI: 10.1111/j.1440-1819.2010.02094.x] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The pathogenesis of schizophrenia has yet to be fully characterized. Gene-environment interactions have been found to play a crucial role in the vulnerability to this disease. Among various environmental factors, inflammatory immune processes have been most clearly implicated in the etiology and pathology of schizophrenia. Cytokines, regulators of immune/inflammatory reactions and brain development, emerge as part of a common pathway of genetic and environmental components of schizophrenia. Maternal infection, obstetric complications, neonatal hypoxia and brain injury all recruit cytokines to mediate inflammatory processes. Abnormal expression levels of specific cytokines such as epidermal growth factor, interleukins (IL) and neuregulin-1 are found both in the brain and peripheral blood of patients with schizophrenia. Accordingly, cytokines have been proposed to transmit peripheral immune/inflammatory signals to immature brain tissue through the developing blood-brain barrier, perturbing structural and phenotypic development of the brain. This cytokine hypothesis of schizophrenia is also supported by modeling experiments in animals. Animals treated with specific cytokines of epidermal growth factor, IL-1, IL-6, and neuregulin-1 as embryos or neonates exhibit schizophrenia-like behavioral abnormalities after puberty, some of which are ameliorated by treatment with antipsychotics. In this review, we discuss the neurobiological mechanisms underlying schizophrenia and novel antipsychotic candidates based on the cytokine hypothesis.
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Affiliation(s)
- Yuichiro Watanabe
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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Rapaport MH, Bresee C. Serial mitogen-stimulated cytokine production from continuously ill patients with schizophrenia. Neuropsychopharmacology 2010; 35:428-34. [PMID: 19759532 PMCID: PMC2794914 DOI: 10.1038/npp.2009.145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/09/2009] [Accepted: 08/12/2009] [Indexed: 11/08/2022]
Abstract
Aberrant activation of the immune system has been implicated in an increasingly large number of disease states and can influence cognition, mood, and memory. There is a long and controversial history of reports of immune activation associated with schizophrenia. In this study, we measured mitogen-stimulated cytokine levels serially in 100 medication-stabilized continuously ill subjects with schizophrenia and compared and contrasted them with mitogen-stimulated cytokine levels from 51 normal volunteers. The subjects with schizophrenia had consistently higher mitogen-stimulated IL-2 levels and lower IL-6 levels than the normal volunteers. These effects could not be explained by medications, smoking, or other clinical variables. We conclude that continuously symptomatic medication-stabilized subjects with schizophrenia have a mitogen-stimulated cytokine expression pattern that is suggestive of ongoing immune activation.
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Affiliation(s)
- Mark H Rapaport
- Department of Psychiatry and Behavioral Neurosciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
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18
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Williams S, Sakic B, Hoffman SA. Circulating brain-reactive autoantibodies and behavioral deficits in the MRL model of CNS lupus. J Neuroimmunol 2009; 218:73-82. [PMID: 19919882 DOI: 10.1016/j.jneuroim.2009.10.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 09/16/2009] [Accepted: 10/13/2009] [Indexed: 12/25/2022]
Abstract
Brain-reactive autoantibodies (BRAA) are hypothesized to play a role in the neuropsychiatric manifestations that accompany systemic lupus erythematosus (SLE). The present study tests the proposed relation between circulating BRAA and behavioral deficits in lupus-prone MRL/lpr mice. Two age-matched cohorts born at different times were used to test the relationship in the context of altered disease severity. Significant correlations between autoimmunity and behavior were detected in both cohorts. These results are the first to report correlations between behavior and autoantibodies to integral membrane proteins of brain, supporting the hypothesis that BRAA contribute to the behavioral dysfunction seen in lupus.
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Affiliation(s)
- S Williams
- Neuroimmunology Labs, School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 USA
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19
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Singh B, Bera NK, Nayak CR, Chaudhuri TK. Decreased serum levels of interleukin-2 and interleukin-6 in Indian Bengalee schizophrenic patients. Cytokine 2009; 47:1-5. [PMID: 19502081 DOI: 10.1016/j.cyto.2009.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 05/10/2009] [Accepted: 05/15/2009] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND PURPOSE Autoimmune process is thought to be involved in the pathophysiology in some cases of schizophrenia. Alteration in interleukin (IL) regulation is regarded as additional proof of autoimmunological background in schizophrenia. Most of the research in interleukin activity in schizophrenia has been in Caucasian and some Mongoloid patients. We have studied the serum IL-2 and IL-6 level in psychotropic medication free and antipsychotic medicating schizophrenic patients who are Indian Bengalee by ethnicity. METHOD Twenty psychotropic medication free and 30 antipsychotic medicating schizophrenic patients who fulfilled DSM-IV-TR criteria and 30 of the same age and sex matched controls were recruited. Serum level of IL-2 and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). RESULT There was a significant decrease of IL-2 and IL-6 in both antipsychotic medicating and psychotropic medication free patients. Further the medicating patients showed lower level of IL-2 and IL-6 than the psychotropic medication free patients. CONCLUSION This is the first study to describe a decrease serum level of IL-6 in schizophrenic patients. The study provides the evidence that some kind of immune dysregulation is involved in pathophysiology of schizophrenia. The study also provides the evidence for the immunosuppressive effect of antipsychotic drugs.
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Affiliation(s)
- Bisu Singh
- Cellular Immunology Laboratory, Department of Zoology, University of North Bengal, Siliguri 734 013, West Bengal, India
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20
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Association study of interleukin 2 (IL2) and IL4 with schizophrenia in a Japanese population. Eur Arch Psychiatry Clin Neurosci 2008; 258:422-7. [PMID: 18574615 DOI: 10.1007/s00406-008-0813-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 03/17/2008] [Indexed: 10/21/2022]
Abstract
Interleukin 2 (IL-2) and IL-4 are pleiotropic cytokines regulating Th1/Th2 balance and have a regulatory activity in brain function. Thus these cytokines have been implicated in the pathophysiology of schizophrenia. The latest studies provided controversial results regarding the genetic associations of these cytokines. The functional polymorphisms, IL2-330T/G and IL4-590C/T, were associated with schizophrenia in a German population, although contradictory findings were also reported in a Korean population. To ascertain whether IL2 and IL4 contribute to vulnerability to schizophrenia, we conducted a moderate-scale case-control (536 patients and 510 controls) association study for seven polymorphisms in Japanese subjects. There were no significant associations of these genes with schizophrenia using either single marker or haplotype analyses. The present study suggests that IL2 and IL4 do not contribute to vulnerability to schizophrenia in the Japanese population.
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21
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O'Brien SM, Scully P, Dinan TG. Increased tumor necrosis factor-alpha concentrations with interleukin-4 concentrations in exacerbations of schizophrenia. Psychiatry Res 2008; 160:256-62. [PMID: 18722671 DOI: 10.1016/j.psychres.2007.11.014] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 07/01/2007] [Accepted: 11/11/2007] [Indexed: 11/16/2022]
Abstract
Several studies have indicated that cytokines may be involved in the pathophysiology of schizophrenia. Previous studies, however, have yielded contradictory results; in this study we assess the plasma levels of both T-helper-1 (Th1) and T-helper-2 (Th2) cytokines in patients with acute exacerbations of schizophrenia. Plasma concentrations of interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-alpha) and soluble receptor of interleukin-6 (sIL-6R) were measured with high sensitivity, enzyme-linked immunosorbent assays (ELISA) in patients with acute exacerbations of schizophrenia as compared with healthy controls. Patients with an acute exacerbation of schizophrenia had significantly increased production of TNF-alpha and significantly reduced production of IL-4 as compared with healthy subjects. No significant difference was observed in IL-6, sIL-6R, IL-8 and IL-10. Acute exacerbations of schizophrenia are associated with increased TNF-alpha concentrations (Th1) with concomitantly reduced concentrations of IL-4 (Th2) and a resulting increased TNF-alpha/IL-4 ratio.
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Affiliation(s)
- Sinead M O'Brien
- Department of Psychiatry and Alimentary Pharmabiotic Centre, University College Cork, Ireland
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Potvin S, Stip E, Sepehry AA, Gendron A, Bah R, Kouassi E. Inflammatory cytokine alterations in schizophrenia: a systematic quantitative review. Biol Psychiatry 2008; 63:801-8. [PMID: 18005941 DOI: 10.1016/j.biopsych.2007.09.024] [Citation(s) in RCA: 716] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 07/30/2007] [Accepted: 09/29/2007] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cytokines play an important role in infection and inflammation and are crucial mediators of the cross-talk between the brain and the immune system. Schizophrenia would be associated with an imbalance in inflammatory cytokines, leading to a decrease in Th1 and an increase in Th2 cytokine secretion. However, data published so far have been inconsistent. The primary objective of the present meta-analysis was to verify whether the cytokine imbalance hypothesis of schizophrenia is substantiated by evidence. METHODS Cross-sectional studies were included if they assessed in vivo plasma or serum cytokine concentrations and/or in vitro secretion of cytokines by peripheral blood leukocytes from schizophrenia patients and healthy volunteers. RESULTS Data from 62 studies involving a total sample size of 2298 schizophrenia patients and 1858 healthy volunteers remained for analysis. Ten cytokines were assessed, including the prototypic Th1 and Th2 cytokines gamma interferon (IFN-gamma) and interleukin 4 (IL-4) as well as IL-2, soluble IL-2 receptor (sIL-2R), IL-1beta, IL-1 receptor antagonist (IL-1RA), tumor necrosis factor-alpha (TNF-alpha), IL-6, soluble IL-6 receptor (sIL-6R), and IL-10. The results show that an increase occurs in in vivo IL-1RA, sIL-2R, and IL-6 and a decrease occurs in in vitro IL-2 in schizophrenia. No significant effect sizes were obtained for the other cytokines. CONCLUSIONS These findings provide the first evidence of establishment of an inflammatory syndrome in schizophrenia, which refutes the current hypothesis of a Th2 slant. Caveats are presented to data interpretation, including the role of stress and the effect of weight gain that develops in schizophrenia.
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Affiliation(s)
- Stéphane Potvin
- Department of Psychiatry, Faculty of Medicine, University of Montreal, Fernand-Seguin Research Center, Louis-H Lafontaine Hospital, Montreal, Quebec, Canada
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Na KS, Kim YK. Monocytic, Th1 and th2 cytokine alterations in the pathophysiology of schizophrenia. Neuropsychobiology 2008; 56:55-63. [PMID: 18037815 DOI: 10.1159/000111535] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Accepted: 07/04/2007] [Indexed: 11/19/2022]
Abstract
A growing body of evidence suggests that changes in the serum levels and cellular production of various cytokines are associated with the immunological abnormalities of schizophrenia. Several studies have examined alterations in T helper type 1 (Th1) and T helper type 2 (Th2) cytokines in schizophrenia. We explored monocytic, Th1 and Th2 cytokines in 43 schizophrenia patients and 50 normal controls. The mitogen-induced production of tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), IL-4, gamma-interferon (IFN-gamma) and IL-2 was measured with enzyme-linked immunosorbent assays before and after antipsychotic treatment. IL-6 and TNF-alpha production by schizophrenic patients was significantly higher than by normal controls, while IL-2, IL-4 and IFN-gamma production was significantly lower in schizophrenic patients. After 6 weeks of antipsychotic treatment, IL-6 and TNF-alpha production was significantly decreased, while IL-4, IFN-gamma and IL-2 productions were not significantly changed. Our results suggest that increased monocytic cytokines and decreased Th1 and Th2 cytokines may be associated with the immunopathogenesis of acute psychotic schizophrenia, and that antipsychotics may play an important role in immune response by decreasing elevated monocytic cytokines.
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Affiliation(s)
- Kyeong-Sae Na
- Department of Psychiatry, Korea University, Ansan, Seoul, Korea
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Watanabe Y, Nunokawa A, Kaneko N, Muratake T, Koizumi M, Someya T. Lack of association between the interleukin-1 gene complex and schizophrenia in a Japanese population. Psychiatry Clin Neurosci 2007; 61:364-9. [PMID: 17610660 DOI: 10.1111/j.1440-1819.2007.01671.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interleukin-1 (IL1) is an inflammatory cytokine and exerts neurodegenerative effects in the brain. Several studies have indicated that IL1 is likely to be involved in the pathogenesis of schizophrenia. Recent genetic studies have revealed that the IL1 gene complex (IL,1 alpha, IL1, beta and IL1 receptor antagonist) was associated with schizophrenia, although contradictory findings have also been reported. To assess whether the IL1 gene complex was implicated in vulnerability to schizophrenia, the authors conducted a case-control association study (416 patients with schizophrenia and 440 control subjects) for nine polymorphisms in Japanese subjects. The authors found no association between the IL1 gene complex polymorphisms and schizophrenia using either single-marker or haplotype analyses. The results of the present study suggest that the IL1 gene complex does not play a major role in conferring susceptibility to schizophrenia in the Japanese population.
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Affiliation(s)
- Yuichiro Watanabe
- Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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Shirts BH, Wood J, Yolken RH, Nimgaonkar VL. Association study of IL10, IL1beta, and IL1RN and schizophrenia using tag SNPs from a comprehensive database: suggestive association with rs16944 at IL1beta. Schizophr Res 2006; 88:235-44. [PMID: 16905295 DOI: 10.1016/j.schres.2006.06.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 06/21/2006] [Accepted: 06/26/2006] [Indexed: 01/31/2023]
Abstract
Genetic association studies of several candidate cytokine genes have been motivated by evidence of immune dysfunction among patients with schizophrenia. Intriguing but inconsistent associations have been reported with polymorphisms of three positional candidate genes, namely IL1beta, IL1RN, and IL10. We used comprehensive sequencing data from the Seattle SNPs database to select tag SNPs that represent all common polymorphisms in the Caucasian population at these loci. Associations with 28 tag SNPs were evaluated in 478 cases and 501 unscreened control individuals, while accounting for population sub-structure using the genomic control method. The samples were also stratified by gender, diagnostic category, and exposure to infectious agents. Significant association was not detected after correcting for multiple comparisons. However, meta-analysis of our data combined with previously published association studies of rs16944 (IL1beta -511) suggests that the C allele confers modest risk for schizophrenia among individuals reporting Caucasian ancestry, but not Asians (Caucasians, n=819 cases, 1292 controls; p=0.0013, OR=1.24, 95% CI 1.09, 1.41).
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Affiliation(s)
- Brian H Shirts
- Department of Psychiatry, University of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, 3811 O'Hara Street, Pittsburgh, Pennsylvania 15213, USA
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Drzyzga L, Obuchowicz E, Marcinowska A, Herman ZS. Cytokines in schizophrenia and the effects of antipsychotic drugs. Brain Behav Immun 2006; 20:532-45. [PMID: 16580814 DOI: 10.1016/j.bbi.2006.02.002] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 02/17/2006] [Indexed: 01/13/2023] Open
Abstract
Growing evidence suggests that the immune, endocrine, and nervous systems interact with each other through cytokines, hormones, and neurotransmitters. The activation of the cytokine systems may be involved in the neuropathological changes occurring in the central nervous system (CNS) of schizophrenic patients. Numerous studies report that treatment with antipsychotic drugs affects the cytokine network. Hence, it is plausible that the influence of antipsychotics on the cytokine systems may be responsible for their clinical efficacy in schizophrenia. This article reviews current data on the cytokine-modulating potential of antipsychotic drugs. First, basic information on the cytokine networks with special reference to their role in the CNS as well as an up-to-date knowledge of the cytokine alterations in schizophrenia is outlined. Second, the hitherto published studies on the influence of antipsychotics on the cytokine system are reviewed. Third, the possible mechanisms underlying antipsychotics' potential to influence the cytokine networks and the most relevant aspects of this activity are discussed. Finally, limitations of the presented studies and prospects of future research are delineated.
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Affiliation(s)
- Lukasz Drzyzga
- Silesian University School of Medicine, Department of Clinical Pharmacology, Medyków 18, 40-752 Katowice, Poland
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Pae CU, Yoon CH, Kim TS, Kim JJ, Park SH, Lee CU, Lee SJ, Lee C, Paik IH. Antipsychotic treatment may alter T-helper (TH) 2 arm cytokines. Int Immunopharmacol 2006; 6:666-71. [PMID: 16504930 DOI: 10.1016/j.intimp.2005.10.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 08/22/2005] [Accepted: 10/14/2005] [Indexed: 11/15/2022]
Abstract
The alteration of T helper 1 (TH1) and TH2 responses and related cell-mediated immunity has been supposed to be associated with the immunological pathogenesis in the development of schizophrenia. Increasing evidence suggested the alteration of cytokines in accordance with the antipsychotic treatment as well, so that this study aimed at investigating the aberration of TH1 and -2 cytokines before and after antipsychotic treatment in patients with schizophrenia. Thirty-five schizophrenic patients with antipsychotic naïve or free more than 2 months participated in the study. We measured the plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-2 (TH1), and IL-6, IL-10 and IL-13 (TH2) at the time of admission and after an 8-week antipsychotic treatment. The IL-6 (p = 0.001) and -13 (p = 0.004) levels were significantly decreased after antipsychotic treatment than those of before antipsychotic treatment. The total and general PANSS score changes were correlated with the change of IL-6 (r = 0.598, corrected p < 0.05; r = 0.550, corrected p = 0.005, respectively). The baseline IL-6 level was correlated with change of general PANSS score (r = 0.449, corrected p = 0.044), whereas changes of other PANSS scores were not correlated with any other baseline cytokine levels. The baseline total PANSS score was correlated with the baseline levels of IL-13 (r = 0.776, corrected p < 0.005). The baseline total and general PANSS scores were correlated with the baseline levels of IL-6 (r = 0.689, corrected p < 0.005; r = 0.653, corrected p < 0.005). The correlations between the baseline levels of cytokines and the duration of illness and the age at onset were not found. Our study supports that TH-2 arm cytokines may be involved in the improvement of psychopathology and symptomatologies of schizophrenia and that antipsychotic drugs may suppress some TH-2 cytokines in patients with schizophrenia.
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Affiliation(s)
- Chi-Un Pae
- Department of Psychiatry, Kangnam St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seocho-Gu, Seoul
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Schwarz MJ, Krönig H, Riedel M, Dehning S, Douhet A, Spellmann I, Ackenheil M, Möller HJ, Müller N. IL-2 and IL-4 polymorphisms as candidate genes in schizophrenia. Eur Arch Psychiatry Clin Neurosci 2006; 256:72-6. [PMID: 16091861 DOI: 10.1007/s00406-005-0603-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Accepted: 05/24/2005] [Indexed: 01/14/2023]
Abstract
An immune process, characterized by a relative predominance of the T helper-2 (Th2) system and possibly induced by a viral infection,may be involved in the pathophysiology of schizophrenia. In this context, functional polymorphisms in the Interleukin-2 (IL-2) and Interleukin-4 (IL-4) genes appear to be principal candidates for genetic schizophrenia research. Further evidence for these candidate genes comes from several linkage analyses, pointing to susceptibility gene loci on chromosomes 4q and 5q, where the genes coding for IL- 2 and IL-4 are located. We carried out a case-control study including 230 schizophrenic patients and 251 healthy persons, investigating the IL-2 -330 T/G single nucleotide polymorphism (SNP) and the IL-4 -590 C/T SNP. A significant association of the IL-2 -330 TT genotype and of the IL-4 -590 CC genotype with schizophrenia could be identified. Our findings may partly account for the relative predominance of the Th2 system in schizophrenia, although they cannot directly explain this immunological imbalance, but may be related to an altered antiviral immune response in patients with schizophrenia.
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Affiliation(s)
- Markus J Schwarz
- Psychiatric Hospital, Ludwig-Maximilian University Munich, Nussbaumstr. 7, 80336, Munich, Germany
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Riedel M, Strassnig M, Schwarz MJ, Müller N. COX-2 inhibitors as adjunctive therapy in schizophrenia: rationale for use and evidence to date. CNS Drugs 2005; 19:805-19. [PMID: 16185091 DOI: 10.2165/00023210-200519100-00001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A better understanding of the human immune system and its complex interactions has resulted in new insights into the pathoaetiological mechanisms of psychiatric disorders. As a result, new treatment options are being explored. Several findings suggest that an imbalanced immune response is involved in the pathophysiology of schizophrenia. COX-2 inhibitors are known to influence the immune system in a way that may redirect this imbalance. Based on these suggestions, the COX-2 inhibitor celecoxib has been tested as a possible adjunctive therapeutic approach in the treatment of schizophrenia. While the first trial using celecoxib as add-on therapy to an atypical antipsychotic showed a significant beneficial effect, recent studies demonstrated that this effect may be limited to patients with recent-onset schizophrenia.
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Affiliation(s)
- Michael Riedel
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilan University of Munich, Munich, Germany
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30
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Sperner-Unterweger B. Immunological aetiology of major psychiatric disorders: evidence and therapeutic implications. Drugs 2005; 65:1493-520. [PMID: 16033289 DOI: 10.2165/00003495-200565110-00004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Historically, immunological research in psychiatry was based on empirical findings and early epidemiological studies indicating a possible relationship between psychiatric symptoms and acute infectious diseases. However, aetiopathological explanations for psychiatric disorders are no longer closely related to acute infection. Nevertheless, immune hypotheses have been discussed in schizophrenia, affective disorders and infantile autism in the last decades. Although the variability between the results of the epidemiological studies conducted to date is strikingly high, there is still some evidence that the immune system might play a role in the aetiopathogenesis of these three psychiatric diseases, at least in subgroups of patients. In anxiety disorders immunological research is still very much in its infancy, and the few and inconsistent data of immune changes in these patients are believed to reflect the influence of short- or long-term stress exposure. Nevertheless, there are also some hints raising the possibility that autoimmune mechanisms could interrupt neurotransmission, which would be of significance in certain patients with anxiety and panic disorders. Drug and alcohol (ethanol) dependence are not believed to be primarily influenced by an immunological aetiology. On the other hand, immune reactions due to different drugs of abuse and alcohol may directly or indirectly influence the course of concomitant somatic diseases. In different organic brain disorders the underlying somatic disease is defined as a primary immune or autoimmune disorder, for instance HIV infection or systemic lupus erythematosus (SLE). For other neurodegenerative disorders, such as Alzheimer's disease, immunoaetiopathological mechanisms are supported by experimental and clinical studies. Treatment strategies based on immune mechanisms have been investigated in patients with schizophrenia and affective disorders. Furthermore, some antipsychotics and most antidepressants are known to have direct or indirect effects on the immune system. Different immunotherapies have been used in autism, including transfer factor, pentoxifylline, intravenous immunoglobulins and corticosteroids. Immunosuppressive and/or immunomodulating agents are well established methods for treating the neuropsychiatric sequelae of immune or autoimmune disorders, for example AIDS and SLE. Therapeutic approaches in Alzheimer's disease also apply immunological methods such as strategies of active/passive immunisation and NSAIDs. Considering the comprehensive interactive network between mind and body, future research should focus on approaches linking targets of the different involved systems.
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Schmitt A, Bertsch T, Tost H, Bergmann A, Henning U, Klimke A, Falkai P. Increased serum interleukin-1beta and interleukin-6 in elderly, chronic schizophrenic patients on stable antipsychotic medication. Neuropsychiatr Dis Treat 2005; 1:171-7. [PMID: 18568063 PMCID: PMC2413198 DOI: 10.2147/nedt.1.2.171.61048] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In schizophrenia, alterations of proinflammatory cytokine levels have been reported and related to the disease and psychopathology. However, only limited conclusions can be drawn in view of confounding factors such as infection, age, sex, smoking, and antipsychotic medication. Chronic schizophrenic patients with a long-term disease process and medication period have not been investigated so far. We have measured serum levels of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)alpha in 41 elderly, chronic schizophrenic patients and 23 age- and sex-matched controls using enzyme-linked immunosorbent assay (ELISA). We assessed detailed psychopathology and neuropsychological performance and determined serum levels of haloperidol, clozapine, and the two main clozapine metabolites, desmethylclozapine and clozapine metabolite N-oxide, by high-pressure liquid chromatography (HPLC). IL-1beta and IL-6 levels were increased in treatment-resistant schizophrenic patients compared with healthy controls, whereas TNFalpha showed no difference. We did not find statistically significant differences of cytokine levels between medication groups and there was no correlation with serum levels of antipsychotics or psychopathological rating scores. Elevations of IL-1beta and IL-6 in elderly chronic schizophrenic patients may be related to an active disease process lasting until old age. Despite missing correlations, long-term treatment effects in treatment-resistant patients may have affected TNFalpha, leading to control levels. Post-mortem and animal studies should clarify the presence of altered immune function in the brain as well as the effect of cytokine levels in relation to neurodevelopmental disturbances and schizophrenia-associated behavior.
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Kim YK, Myint AM, Lee BH, Han CS, Lee HJ, Kim DJ, Leonard BE. Th1, Th2 and Th3 cytokine alteration in schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2004; 28:1129-34. [PMID: 15610925 DOI: 10.1016/j.pnpbp.2004.05.047] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/10/2004] [Indexed: 01/07/2023]
Abstract
BACKGROUND Several studies have shown that there is an imbalance between T helper 1 (Th1) cytokines and T helper 2 (Th2) cytokines in patients with schizophrenia. The T helper 3 (Th3) cytokine, transforming growth factor beta-1 (TGF-beta1), has been shown to suppress the production of Th1 cytokines. Therefore it is hypothesized that it may play a role in schizophrenia by suppressing overactive Th1 system. METHODS We recruited 88 schizophrenic patients and 88 matched controls. The basal plasma concentrations of IFN-gamma (Th1), IL-4 (Th2) and TGF-beta1 (Th3) were studied at the time the patients were admitted to the hospital and following 8 weeks of treatment with antipsychotics. RESULTS The detection rate of plasma IFN-gamma and basal plasma TGF-beta1 level were significantly higher in schizophrenic patients than in controls whereas detection rate of plasma IL-4 was lower in patients. The ratio of Th1/Th2 cytokines (IFN-gamma/IL-4) was higher in schizophrenic patients. Following the neuroleptic treatment, the IFNgamma and TGF-beta1 levels returned to control values, and IL-4 concentration rose above the control value. CONCLUSION Schizophrenic patients showed higher Th1/Th2 ratio which is attenuated by effective neuroleptic treatment. It is possible that TGF-beta1 plays a role in reducing the activity of Th1 cytokine.
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Affiliation(s)
- Yong-Ku Kim
- Department of Psychiatry, Korea University College of Medicine, Ansan Hospital, 516, Go-Jan Dong, Ansan City, Kyunggi Province 425-070, South Korea.
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Liu HC, Yang YY, Chou YM, Chen KP, Shen WW, Leu SJ. Immunologic variables in acute mania of bipolar disorder. J Neuroimmunol 2004; 150:116-22. [PMID: 15081255 DOI: 10.1016/j.jneuroim.2004.01.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Revised: 01/05/2004] [Accepted: 01/05/2004] [Indexed: 10/26/2022]
Abstract
Macrophages, lymphocytes and their products, may be involved in the pathophysiology of psychiatric disorders. The cell-mediated immune activation response of manic patients during pre-medication and medication stages remains unclear. The purpose of this case-control study was to investigate the plasma levels of immunologic variables, including interleukin (IL)-1 receptor antagonist (IL-1RA), soluble CD 4 (sCD4) and sCD8, and TH1 (interferon [IFN]-gamma and IL-2) and TH2 (IL-4 and IL-10) cytokines in patients with pre-medicated, medicated bipolar mania. The study subjects, aged 16-44 years, were physically healthy patients with Young Mania Rating Scale (YMRS) scores > or =26, and normal controls, aged 19-40 years, were matched for sex. The immune variables were measured in acute mania and in consequent remission (YMRS scores < or =12) among bipolar patients. The plasma levels of IL-1RA, sCD4, and sCD8 were found significantly increased in pre-medicated acute manic patients as compared to normal controls. But only IL-1RA and sCD8 were found different in remitted bipolar patients as compared to normal controls. For TH1 cytokines, culture supernatant level of IFN-gamma was found significantly lower in manic patients of both acute and remission stages as compared to normal controls. No significant difference was found in IL-2 level in pre-medicated acute manic patients compared to controls. For TH2 cytokines, no significant differences in IL-4 and IL-10 levels were observed. We showed that cell-mediated immune response was activated in patients with bipolar disorder during the pre-medication, medication, and the remission stages. Our study findings suggest that the immune-modulation in patients with bipolar disorder may be abnormal.
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Affiliation(s)
- Hsing-Cheng Liu
- Graduate Institute of Cell and Molecular Biology, Taipei Medical University, Taipei, Taiwan
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Kim YK, Suh IB, Kim H, Han CS, Lim CS, Choi SH, Licinio J. The plasma levels of interleukin-12 in schizophrenia, major depression, and bipolar mania: effects of psychotropic drugs. Mol Psychiatry 2003; 7:1107-14. [PMID: 12476326 DOI: 10.1038/sj.mp.4001084] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2001] [Revised: 11/05/2001] [Accepted: 01/16/2002] [Indexed: 11/08/2022]
Abstract
Interleukin-12 (IL-12) plays a key role in promoting T helper 1 (Th1) responses and subsequent cell-mediated immunity. Given the role of cytokines in the pathogenesis of psychiatric disorders, the dysregulation of IL-12 in these illnesses would be expected. We measured the plasma levels of IL-12 in 102 psychiatric patients (43 schizophrenia, 34 major depression and 25 bipolar disorder) and 85 normal controls. In addition, IL-12 levels of the patients were measured after an 8-week treatment to assess whether the levels were affected by medication. The IL-12 levels of the patient group with major depression were significantly higher than that of the control group, whereas no differences were found among the other groups. IL-12 values of the three patient groups decreased significantly after 8 weeks of treatment. These findings support the hypothesis that activation of the inflammatory response system and in particular of Th-1-like cells, is involved in the pathophysiology of major depression and that repeated administration of antidepressive and antipsychotic drugs may suppress IL-12 plasma concentrations in psychiatric patients.
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Affiliation(s)
- Y-K Kim
- Department of Psychiatry, Korea University Ansan Hospital, College of Medicine, Korea.
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35
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Gaughran F. Immunity and schizophrenia: autoimmunity, cytokines, and immune responses. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2003; 52:275-302. [PMID: 12498108 DOI: 10.1016/s0074-7742(02)52013-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As is evident from the present account, there is no single or persuasive argument that signals emanating from the immune system are directly involved in the etiology of schizophrenia. We do not even know if we are dealing with a single disorder with a single causality; almost certainly we are not. The precise etiology of schizophrenia, as with so many neurological disorders, remains obscure. However, there is abundant evidence in schizophrenia of mutual dysregulation of neuronal function and immune system activity. Although this evidence is not always consistent, a pattern emerges suggesting aspects of immune activity being involved in the pathology of neuronal development that characterizes schizophrenia. Exposure to infective agents, HLA associations, autoimmune associations, disturbances in lymphocyte populations, and cytokine imbalances with a skew toward Th2 activity are supportive of this view. That the evidence is not always consistent is a testament to the complexity and heterogeneity of the disorder, to confounding by antipsychotics that themselves are immunomodulatory, and to the multifaceted nature, with all its checks and balances, of the immune system itself.
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Affiliation(s)
- Fiona Gaughran
- Ladywell Unit, University Hospital, Lewisham, London SE13 6LH, United Kingdom
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36
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37
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Zhang XY, Zhou DF, Zhang PY, Wu GY, Cao LY, Shen YC. Elevated interleukin-2, interleukin-6 and interleukin-8 serum levels in neuroleptic-free schizophrenia: association with psychopathology. Schizophr Res 2002; 57:247-58. [PMID: 12223256 DOI: 10.1016/s0920-9964(01)00296-1] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cytokines have been one of the recent focal points of immunological research in schizophrenia. The present study was to assess the serum levels of some of interleukins in schizophrenia and their relationships with the psychopathological parameters. Seventy physically healthy Chinese patients, who met DSM-III-R criteria for schizophrenia and who were drug-free for at least 2 weeks, were compared with 30 age- and sex-matched Chinese normal controls. The psychopathology of schizophrenia was assessed by the Positive and Negative Syndrome Scale (PANSS). Serum levels of IL-6 and IL-8 were measured by sandwich enzyme-linked immunosorbent assay (ELISA), and serum IL-2 level was assayed by radioimmunometric assay (RIA). Serum levels of IL-2, IL-6 and IL-8 were significantly elevated in patients with a chronic form of schizophrenia (all p<0.05). There was a significant inverse relationship between IL-2 level and the PANSS positive subscale P (r=-0.31, p=0.006) and a significant positive correlation between IL-8 level and PANSS negative subscale N (r=0.25, p=0.036) in schizophrenic patients. In control subjects, a significant and positive relationship between serum IL-2 and IL-6 (r=0.513, p=0.004) was noted, whereas, there was a significant and negative relationship between IL-2 and IL-8 in schizophrenic patients (r=-0.28, p=0.02). Our data confirms and supports the view that immune disturbance is involved in schizophrenia, which is compatible with the possibility that Chinese schizophrenic patients have an ongoing autoimmune process. This immune disturbance is related to the subgroup of schizophrenic patients with characteristic clinical variables. The dysfunction of interaction or inter-adjustment between different cytokines may exist in schizophrenic patients.
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Affiliation(s)
- Xiang Yang Zhang
- Institute of Mental Health, Peking University, Beijing, People's Republic of China [corrected].
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Zhang XY, Zhou DF, Cao LY, Zhang PY, Wu GY. Decreased production of interleukin-2 (IL-2), IL-2 secreting cells and CD4+ cells in medication-free patients with schizophrenia. J Psychiatr Res 2002; 36:331-6. [PMID: 12127601 DOI: 10.1016/s0022-3956(02)00023-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There are a number of indications that schizophrenia is associated with changes in the immune system. Although functional studies have mostly demonstrated decreased in vitro production of IL-2 by peripheral blood mononuclear cells (PBMCs) stimulated with mitogen, the reason is unclear. The aim of the study was to explore the relationship between IL-2 production and CD4+ cells which mainly secret IL-2 in non-Caucasian patients with schizophrenia. Blood CD4+ cells and mitogen-stimulated IL-2 secreting cells identified by an immunohistochemical study with the alkaline phosphatase/anti-alkaline phosphatase (APAAP) technique, and in vitro IL-2 production with radioimmunometric assay (RIA) were measured in 30 schizophrenic patients and 30 normal control subjects matched for sex, age and race. The results showed that blood CD4+ cells and mitogen-induced IL-2 secreting cells and IL-2 production were significantly lower in schizophrenic subjects than in the normal controls. There was significantly positive correlation between CD4+ cells and IL-2 production in normal controls but not in patients. These findings suggest that immune disturbance may be present in schizophrenic patients. The lower in vitro IL-2 production is probably related to the decreased number of T-cells that secret IL-2, as well as to the intrinsic disorder of the patients' T cells.
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Affiliation(s)
- Xiang Yang Zhang
- Institute of Mental Health, School of Medicine, Peking University, Beijing, China.
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Kim DJ, Kim W, Yoon SJ, Go HJ, Choi BM, Jun TY, Kim YK. Effect of risperidone on serum cytokines. Int J Neurosci 2002; 111:11-9. [PMID: 11913333 DOI: 10.3109/00207450108986549] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A variety of cytokines are dysregulated in schizophrenia, and some antipsychotic drugs effect cytokines. In order to examine the effect of risperidone on plasma cytokines, we measured the serum level of IL-1b, IL-2, IL-6, IL-12, and INF-g during acute states of illness, and after 4 weeks of treatment with risperidone in 19 schizophrenic patients. The patients' psychopathology was assessed by PANSS. Plasma IL-12 levels increased significantly after 4 weeks of treatment (p = .002). Plasma IL-b, IL-2, IL-6, and INF-g levels were not significantly different before and after treatment. There were no significant correlations between the changes in cytokine levels and the changes in PANSS scores. Increased IL-12 may contribute to activation of immune responses during treatment with risperidone. IL-12 may play an important role in immune responses related to neuropsychiatry.
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Affiliation(s)
- D J Kim
- Department of Psychiatry, Holy Family Hospital, Catholic University of Korea, 420-717, 2 Sosa-Dong, Wonmi-Gu, Buchon City, Kyunggi Do, Korea.
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40
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Ebrinç S, Top C, Oncül O, Başoğlu C, Cavuşlu S, Cetin M. Serum interleukin 1 alpha and interleukin 2 levels in patients with schizophrenia. J Int Med Res 2002; 30:314-7. [PMID: 12166349 DOI: 10.1177/147323000203000313] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
It has been suggested that altered interleukin (IL) regulation may be involved in the pathogenesis of schizophrenia. In this cross-sectional, case-controlled study, patients with schizophrenia and a control group of healthy subjects, matched by age, sex and body mass index, were evaluated. The levels of IL-1 alpha and IL-2 in blood serum were measured by enzyme-linked immunosorbent assay. The fasting serum IL-2 levels were significantly higher in patients with schizophrenia compared with the control subjects, but there was no difference between the fasting serum levels of IL-1 alpha in patients with schizophrenia and the control subjects. Our results suggest that patients with schizophrenia have altered IL-2, but not IL-1 alpha, regulation.
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Affiliation(s)
- S Ebrinç
- Department of Psychiatry, Gülhane Military Medical Academy, Haydarpaşa Training Hospital, Istanbul, Turkey.
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41
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Cazzullo CL, Sacchetti E, Galluzzo A, Panariello A, Adorni A, Pegoraro M, Bosis S, Colombo F, Trabattoni D, Zagliani A, Clerici M. Cytokine profiles in schizophrenic patients treated with risperidone: a 3-month follow-up study. Prog Neuropsychopharmacol Biol Psychiatry 2002; 26:33-9. [PMID: 11853116 DOI: 10.1016/s0278-5846(01)00221-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An increasing body of evidence suggests a role for the immune system in the pathogenesis of schizophrenia. The information concerning the effects of antipsychotics on cytokine profiles are limited and often controversial in particular regarding novel antipsychotics. The authors first investigated the production of various cytokines [interleukin (IL)-2, IL-4, IL-10, interferon (INF)-gamma] in drug-free (n = 12) and drug-naive (n = 3) schizophrenic patients and in healthy controls (n = 33) and then the modifications of cytokines values during a 3-month period of treatment with risperidone. In the baseline condition, the production of IL-2 and INF-gamma was significantly higher (P = .023 and .026, respectively) in patients than in controls. In the same patients, the use of risperidone was associated with augmented IL-10 (a suppressor of Type I cytokines) and decreased INF-gamma production. This modification suggests that clinical improvement is associated with a reduction in the inflammatory-like situation present in not currently treated schizophrenic patients.
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Affiliation(s)
- Carlo L Cazzullo
- Association for the Research on Schizophrenia, Fondazione Legrenzi, Milan, Italy
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42
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Rothermundt M, Arolt V, Bayer TA. Review of immunological and immunopathological findings in schizophrenia. Brain Behav Immun 2001; 15:319-39. [PMID: 11782102 DOI: 10.1006/brbi.2001.0648] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The involvement of immunological and immunopathological mechanisms in the etiopathogenesis of schizophrenia has been a matter of research, with recently increasing effort. This article reviews the findings focusing on postmortem neuropathology, the blood-brain barrier, antibodies, acute phase proteins, immunocompetent cells, and activation markers of immunocompetent cells. Evidence for the two primarily postulated hypotheses (the infectious hypothesis and the autoimmune hypothesis) is critically discussed. On the basis of the findings, perspectives for future research are outlined aiming at a precise and consequent strategy to elucidate a potential involvement of immune mechanisms in the etiopathogenesis of schizophrenia.
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Affiliation(s)
- M Rothermundt
- Department of Psychiatry, University of Muenster, Muenster, Germany
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43
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Hinze-Selch D, Pollmächer T. In vitro cytokine secretion in individuals with schizophrenia: results, confounding factors, and implications for further research. Brain Behav Immun 2001; 15:282-318. [PMID: 11782101 DOI: 10.1006/brbi.2001.0645] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present paper reviews the results of all publications on in vitro cytokine secretion in patients with schizophrenia, as published by March 2001. The authors supply easy to read tables with respect to the individual cytokines and soluble cytokine receptors investigated, the in vitro methodology used, characterization of the patient samples, and the results on cytokine secretion as stated in these studies. Inconsistent results, e.g., regarding in vitro secretion of IL-2 with 11/18 studies finding decreased secretion, 5/18 finding no change, and 2/18 finding increases, cannot systematically be correlated with any methodological procedures nor any diagnostic subtypes, per se. However, factors such as medication and cigarette smoking are likely to play a role. The authors suggest that more hypothesis-driven research, together with more carefully designed studies, as well as better communication between basic or animal researchers and clinicians might help to answer the question of whether there are meaningful peripheral changes in the immune system related to schizophrenia.
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Affiliation(s)
- D Hinze-Selch
- Department of Psychiatry and Psychotherapy, Christian-Albrechts University, Niemannsweg 147, D-24105 Kiel, Germany
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44
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Schwarz MJ, Chiang S, Müller N, Ackenheil M. T-helper-1 and T-helper-2 responses in psychiatric disorders. Brain Behav Immun 2001; 15:340-70. [PMID: 11782103 DOI: 10.1006/brbi.2001.0647] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The expanding field of psychoneuroimmunology has markedly increased knowledge about the interference of the central nervous system and the immune system. Immunological abnormalities in psychiatric patients have been repeatedly described in the last century. Modern concepts of immunology and the growing knowledge of psychoneuroimmunology may help in understanding the distinct immunological mechanisms in psychiatric disorders. One of these concepts regarding the adaptive immune system is the discrimination between Th1-like cell-mediated and Th2-like antibody-related immune responses. This article systematically describes alterations of Th1- or Th2-specific parameters in the major psychiatric disorders schizophrenia, major depression, and Alzheimer's disease. There are several hints of associations of these two distinct arms of immune response with subgroups of schizophrenia and major depression. The immunological research in Alzheimer's disease has already led to a preclinical model of immunotherapy. Categorization of immune parameters may also help to identify a possible immune-related pathophysiology in psychotic and affective disorders, resulting in specific treatment strategies.
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Affiliation(s)
- M J Schwarz
- Psychiatric Hospital, University of Munich, Nussbaumstr. 7, D-80336 Munich, Germany
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45
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Cazzullo CL, Sacchetti E, Galluzzo A, Panariello A, Colombo F, Zagliani A, Clerici M. Cytokine profiles in drug-naive schizophrenic patients. Schizophr Res 2001; 47:293-8. [PMID: 11278147 DOI: 10.1016/s0920-9964(00)00046-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A large body of evidence concerning immunological abnormalities in schizophrenic patients seems to suggest a role of the immune system in the multifactorial pathogenesis of schizophrenia. We investigated the production of various cytokines [interleukin (IL)-2, IL-4, IL-10, interferon (INF)-gamma] in drug-free (n=26) and drug-naive (n=7) schizophrenic patients and in healthy controls (n=33). Production of IL-2 and INF-gamma was significantly higher (respectively P=0.021 and P=0.001) in patients than in controls. These findings provide further evidence that immunological abnormalities are present in some schizophrenic patients.
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Affiliation(s)
- C L Cazzullo
- Association for Research on Schizophrenia (A.R.S.), Fondazione Legrenzi, via Francesco Tamagno 5, 20124 Milan, Italy.
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46
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Kim YK, Kim L, Lee MS. Relationships between interleukins, neurotransmitters and psychopathology in drug-free male schizophrenics. Schizophr Res 2000; 44:165-75. [PMID: 10962218 DOI: 10.1016/s0920-9964(99)00171-1] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
It has been postulated that altered interleukin (IL) regulation may be involved in the pathogenesis of schizophrenia. We therefore investigated the relationships between interleukins, neurotransmitters, and psychopathology in schizophrenia. IL-1beta, IL-2, IL-6, homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in the plasma of neuroleptic-free male schizophrenics in comparison to age-matched healthy male controls (n=25 each). The patients' psychopathology was assessed by the Scale for the Assessment of Positive and Negative Symptoms (SAPS, SANS). The above variables were measured during acute states of illness and after eight weeks of treatment with haloperidol. The plasma levels of IL-2 and HVA were significantly higher in patients compared to controls. In schizophrenic patients, there were significant correlations between IL-2 and HVA, IL-2 and SAPS, and HVA and SAPS during the acute state of illness. The level of IL-6 was significantly correlated to SANS and duration of illness. In schizophrenic patients, the plasma levels of IL-2 and HVA were significantly lowered after treatment with haloperidol. Changes in IL-2 and HVA significantly correlated to those in HVA and SAPS, respectively. These results strongly suggest that the cytokines may modulate dopaminergic metabolism and schizophrenic symptomatology in schizophrenia.
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Affiliation(s)
- Y K Kim
- Department of Psychiatry, College of Medicine, Korea University, Ansan, South Korea.
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47
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Haack M, Hinze-Selch D, Fenzel T, Kraus T, Kühn M, Schuld A, Pollmächer T. Plasma levels of cytokines and soluble cytokine receptors in psychiatric patients upon hospital admission: effects of confounding factors and diagnosis. J Psychiatr Res 1999; 33:407-18. [PMID: 10504009 DOI: 10.1016/s0022-3956(99)00021-7] [Citation(s) in RCA: 231] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
It has been hypothesized that the immune system plays a pathogenetic role in psychiatric disorders, in particular in major depression and schizophrenia. This hypothesis is supported by a number of reports on altered circulating levels and in vitro production of cytokines in these disorders. However, the respective evidence is not consistent. This may be in part due to an incomplete control for numerous confounding influences in earlier studies. We investigated the plasma levels of cytokines and soluble cytokine receptors in psychiatric patients (N = 361) upon hospital admission and compared the results to those obtained in healthy controls (N = 64). By multiple regression analysis we found that circulating levels of interleukin-1 receptor antagonist (IL-1Ra), soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptors (sTNF-R p55, sTNF-R p75) and IL-6 were significantly affected by age, the body mass index (BMI), gender, smoking habits, ongoing or recent infectious diseases, or prior medication. Cytokine or cytokine receptor levels were significantly increased in patients treated with clozapine (sIL-2R, sTNF-R p75), lithium (TNF-alpha, sTNF-R p75, IL-6) or benzodiazepines (TNF-alpha, sTNF-R p75). Taking all these confounding factors into account, we found no evidence for disease-related alterations in the levels of IL-1Ra, sIL-2R, sTNF-R p75 and IL-6, whereas levels of TNF-alpha and sTNF-R p55 in major depression and sTNF-R p55 in schizophrenia were slightly decreased compared to healthy controls. We conclude that, if confounding factors are carefully taken into account, plasma levels of the above mentioned cytokines and cytokine receptors yield little, if any, evidence for immunopathology in schizophrenia or major depression.
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Affiliation(s)
- M Haack
- Max Planck Institute of Psychiatry, Munich, Germany
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