Explorando o componente inflamatório da esquizofrenia / Targeting the inflammatory component of schizophrenia

A esquizofrenia é uma doença heterogênea caracterizada por um conjunto de manifestações clínicas. Um grande número de estudos ao longo dos últimos 20 anos apontou para anormalidades no sistema imune em pacientes que sofrem dessa condição. Em adição, tem sido mostrado que a psicose e a disfunção cognitiva associadas com a esquizofrenia estão ligadas a doenças autoimunes. Aqui, revisamos a evidência que sugere que um status pró-inflamatório do sistema imune induz sintomas psicopatológicos e pode estar envolvido na fisiopatologia dessa principal doença mental. Também propomos que futuros estudos pré-clínicos e clínicos deveriam levar em conta tais causas predefinidas e o status do componente inflamatório. Estratificação de pacientes e estratégias de medicina personalizadas baseadas no direcionamento ao componente inflamatório da doença poderiam ajudar na redução de sintomas e da progressão da doença. Por fim, isso poderia levar a novos conceitos na identificação de alvos moleculares em esquizofrenia e estratégias de descoberta de drogas

Schizophrenia is a heterogeneous disease characterised by an array of clinical manifestations. A large number of studies over the last 20 years have pointed towards immune system abnormalities in patients suffering from this condition. In addition, the psychosis and cognitive dysfunction associated with schizophrenia have been shown to be linked with autoimmune diseases. Here, we review the evidence, which suggests that a pro-inflammatory status of the immune system induces psychopathologic symptoms and may be involved in the pathophysiology of this major mental illness. We also propose that future preclinical and clinical studies should take such pre-defined causes and the dynamic status of the inflammatory component into account. Patient stratification and personalised medicine strategies based on targeting the inflammatory component of the disease could help in alleviation of symptoms and slowing disease progression. Ultimately, this could also lead to novel concepts in schizophrenia target/molecular identification and drug discovery strategies

Animal models of prenatal immune challenge and their contribution to the study of schizophrenia: a systematic review

Prenatal immune challenge (PIC) in pregnant rodents produces offspring with abnormalities in behavior, histology, and gene expression that are reminiscent of schizophrenia and autism. Based on this, the goal of this article was to review the main contributions of PIC models, especially the one using the viral-mimetic particle polyriboinosinic-polyribocytidylic acid (poly-I:C), to the understanding of the etiology, biological basis and treatment of schizophrenia. This systematic review consisted of a search of available web databases (PubMed, SciELO, LILACS, PsycINFO, and ISI Web of Knowledge) for original studies published in the last 10 years (May 2001 to October 2011) concerning animal models of PIC, focusing on those using poly-I:C. The results showed that the PIC model with poly-I:C is able to mimic the prodrome and both the positive and negative/cognitive dimensions of schizophrenia, depending on the specific gestation time window of the immune challenge. The model resembles the neurobiology and etiology of schizophrenia and has good predictive value. In conclusion, this model is a robust tool for the identification of novel molecular targets during prenatal life, adolescence and adulthood that might contribute to the development of preventive and/or treatment strategies (targeting specific symptoms, i.e., positive or negative/cognitive) for this devastating mental disorder, also presenting biosafety as compared to viral infection models. One limitation of this model is the incapacity to model the full spectrum of immune responses normally induced by viral exposure.

Serum levels of IL-6, IL-10 and TNF-α in patients with bipolar disorder and schizophrenia: differences in pro- and anti-inflammatory balance / Níveis séricos de IL-6, IL-10 e TNF-α em pacientes com transtorno bipolar e esquizofrenia: diferenças no equilíbrio pró e antiinflamatório

OBJECTIVE: Previous reports suggest that cytokines act as potential mediators of the interaction between the immune and neuroendocrine systems, and that a proinflammatory state may be associated with bipolar disorder and schizophrenia. The aim is to compare cytokine levels in both disorders. METHOD: Twenty euthymic bipolar disorder patients, 53 chronic stabilized schizophrenia patients and 80 healthy controls were recruited. Subjects were all non-smokers and non-obese. Cytokines TNF-α, IL-6, and IL-10 were examined by sandwich ELISA. RESULTS: IL-6 levels were increased in schizophrenia patients when compared to controls (p < 0.0001) and euthymic bipolar disorder patients (p < 0.0001). IL-6 levels were no different in controls compared to euthymic bipolar disorder patients (p = 0.357). IL-10 was lower in controls compared to schizophrenia patients (p = 0.001) or to bipolar disorder patients (p = 0.004). There was no significant difference in TNF-α serum levels among the groups (p = 0.284). Gender-based classification did not significantly alter these findings, and no correlation was found between the antipsychotic dose administered and cytokine levels in patients with schizophrenia. DISCUSSION: These findings evidence a chronic immune activation in schizophrenia. Bipolar disorder seems to present an episode-related inflammatory syndrome. Increased anti-inflammatory factor IL-10 in bipolar disorder and schizophrenia suggests different patterns of inflammatory balance between these two disorders. Results further support the need to investigate cytokines as possible biomarkers of disease activity or treatment response.

OBJETIVO: Pesquisas sugerem as citocinas como potenciais mediadores da interação entre os sistemas imune e neuroendócrino, e que existe um estado pró-inflamatório associado com transtorno bipolar e esquizofrenia. O objetivo deste estudo é comparar os níveis de citocinas entre os dois distúrbios. MÉTODO: Vinte pacientes com transtorno bipolar eutímicos, 53 pacientes com esquizofrenia crônica estabilizados e 80 controles saudáveis foram recrutados. Todos os indivíduos eram não-fumantes e não-obesos. As citocinas TNF-α, IL-6 e IL-10 foram examinadas por ELISA sanduíche. RESULTADOS: A IL-6 estava aumentada nos pacientes com esquizofrenia quando comparados aos controles (p < 0,0001) e aos pacientes bipolares eutímicos (p < 0,0001). Os níveis de IL-6 não foram diferentes nos controles em comparação com pacientes com transtorno bipolar eutímicos (p = 0,357). Os níveis de IL-10 foram menores nos controles quando comparados aos pacientes com esquizofrenia (p = 0,001) ou aos bipolares (p = 0,004). Não houve diferença significativa nos níveis séricos de TNF-α entre os grupos (p = 0,284). A separação por sexo não mostrou diferenças significativas e não houve correlação entre a dose de antipsicóticos e os níveis de citocinas em pacientes com esquizofrenia. DISCUSSÃO: Estes resultados evidenciam uma ativação imune crônica na esquizofrenia. O transtorno bipolar parece apresentar um aumento da atividade inflamatória relacionado ao episódio de humor. Níveis maiores de IL-10 no transtorno bipolar e esquizofrenia sugerem diferentes padrões de equilíbrio inflamatório entre esses dois transtornos. Resultados fornecem apoio adicional para a investigação de citocinas como possíveis biomarcadores para a atividade da doença ou resposta ao tratamento.

Esquizofrenia: uma doença inflamatória?: [revisão] / Schizophrenia: an inflammatory disease?: [review]

OBJETIVO: Neste estudo, o objetivo foi revisar o papel de um possível processo inflamatório na gênese da esquizofrenia. MÉTODO: Foram selecionados os trabalhos publicados em revistas indexadas nas bases de dados Lilacs e MedLine, sob os unitermos "esquizofrenia", "inflamação" e "estresse oxidativo", nos últimos 10 anos até dezembro de 2009, nos idiomas inglês e português. Foram excluídos os artigos que tratavam de aspectos fisiopatológicos da doença fora do interesse da psiquiatria. RESULTADOS: Sessenta e um artigos foram selecionados. Doze abordavam o envolvimento do estresse oxidativo na esquizofrenia, nove tratavam de alterações no sistema imunológico de pacientes esquizofrênicos, dezesseis da infecção pré-natal como desencadeador da doença e sete mostravam a ação antioxidante e anti-inflamatória de fármacos antipsicóticos. CONCLUSÃO: Os estudos enfatizam o envolvimento do sistema imunológico (isto é, interleucinas e ação anti-inflamatória dos antipsicóticos), das infecções, do estresse oxidativo e da função mitocondrial na fisiopatologia da esquizofrenia. Portanto, esses novos achados são importantes para a melhor compreensão e, consequentemente, a elaboração de terapias mais específicas e eficazes no combate dessa doença mental.

OBJECTIVE: We aimed at reviewing about the influence of the inflammatory process in the genesis of schizophrenia. METHOD: A search for papers published in Lilacs and MedLine databases during the last 10 years until December 2009 was made using the terms "schizophrenia", "inflammation" and "oxidative stress". The papers concerning other pathophysiologic aspects of schizophrenia not exclusively related to psychiatry were excluded. RESULTS: Sixty-one articles were selected: twelve were involved the role of oxidative stress, nine dealt with changes in the immune system, and sixteen referred to prenatal infection as the trigger of schizophrenia. Seven articles showed the anti-inflammatory and antioxidant action of antipsychotic drugs. CONCLUSION: The studies emphasized the importance of the mitochondrial function, oxidative stress, immunological system (interleukin, anti-inflammatory action of the antipsychotics) and infections in the pathophysiology of schizophrenia. These findings are important for a better understanding and consequently the development of more specific and effective therapies for schizophrenia.

Puzzling peptides from a phage display library

The commercial availability of random peptide libraries displayed on the M 13 phage increased their use for studies on epitope identification, enzyme inhibitors and receptor ligands. We planed two experiments for selection of peptides. First, with sheep antibodies, the positive selector was IgG, prepared on Protein G columns from a pool of 11 sheep protected with a vaccine prepared from larvae of Lucilia cuprina, against blowfly strike and the negative selectors were the IgG from the same sheep before vaccination and IgG from vaccinated sheep which were not protected. Four rounds of positive and negative selection were done respectively. In the second experiment, human IgG again prepared on new Protein G columns. Four rounds of positive selection with either IgG from MS or schizophrenia patients were done. They were alternated with two negative selections of schizophrenia IgG on the MS associated peptides and vice versa and two negative selections on each with the IgG from people who had died from non-nervous system diseases as control. After the fourth negative selection of each experiment, the phage were amplified and random closes were picked for nucleotide sequencing. A total of 44 peptides were sorted with the PILEUP program. From those, 15 peptides had a large number with either 4 or 5 methionines

Aspectos inmunológicos de los pacientes psicóticos / Immunological aspects of psychotic patients

En un estudio de pacientes con tiroideopatías en el Hospital Escuela de Tegucigalpa, se encontraron cuatro pacientes con psicosis y valores altos de anticuerpos antimicrosomales y antitiroglobulinas. En un estudio control la presencia de anticuerpos antitiroideos (ATT) esta asociada con alta incidencia de antecedentes familiares de enfermedades inmunológicas, tiroideas y mentales, especialmente esquizofrenia

Inmunoglobulinas séricas en esquizofrenia y psicosis maníaco depresiva

Se investigaron los niveles séricos de las inmunoglobulinas IgA, IgE, IgG e IgM en 13 pacientes esquizofrénicos y 17 maníacos depresivos. La IgE reportó valores por encima de lo normal en el 86.67% de los casos, la IgM en el 33.67% la IgA en el 23.32%; la IgG reportó valores por debajo de lo normal en el 3.33% de los casos. La esquizofrenia superó discretamente a la psicosis maníaco-depresiva en dichoss porcentajes. Todos los casos de esquizofrenia tuvieron alteraciones de la IgE y el único caso con alteración en la IgG fue esquizofrénicos. Se hipotetiza sobre el probable mecanismo responsable de las alteraciones encontradas