Objetivo: Determinar la Amplitud de distribución eritrocitaria-RDW según la severidad de pacientes con sepsis y sin sepsis hospitalizados en la Unidad de Cuidados Intensivos médico quirúrgica del HNERM Octubre – Diciembre 2013. Material y Métodos: Estudio de diseño analítico, tipo transversal; se estudiara a toda la población hospitalizada en el Departamento de UCI con y sin sepsis y pacientes que serán operados electivamente de cirugía Cardiaca, cirugía de Whipple y pacientes neurológicos. Se describirá mediante un análisis descriptivo la edad, género y foco séptico; de la Historia Clínica se determinará si el paciente cumple criterios de sepsis y se determinará si es sepsis severa, shock séptico o disfunción multiórganica (DMO); en el hemograma de ingreso se tomarán los valores de RDW, Hemoglobina (Hb), Hematocrito (Hct) y Volumen Corpuscular Medio (VCM), finalmente se calculará el APACHE II y SOFA. Resultados: De los 61 pacientes seleccionados, 30 fueron catalogados como controles y 31 como casos, estos últimos se subdividieron según la severidad de sepsis, 6 como sepsis, 13 como sepsis severa, 10 como shock séptico, y 2 como DMO. Respecto a los datos demográficos hubieron 46(75%) varones y 15(25%) mujeres; en los grupos de edades de 20 a 59 años hubieron 20(33%) y de 60 a más hubieron 41(67%). Se evidencia una diferencia significativa comparando el valor del RDW de los pacientes sin sepsis y con sepsis según severidad (p= 0.000, IC 95%), la mediana del RDW en los pacientes controles fue de 13.7%, en los pacientes con sepsis 15.5%, con sepsis severa 15.6%, con shock séptico 16% y con DMO 16.15%.Al comparar el valor del RDW con el APACHE II en el grupo de pacientes sépticos se encuentra una correlación moderada r: 0.546 con un (p=0.002, IC 95%), no se encontró esta relación con el SOFA. Finalmente la media de Hb en pacientes sin sepsis fue 11.8 gr/dl, con sepsis 11.4 gr/dl, con sepsis severa 9.5 gr/dl, con shock séptico 8.9 gr/dl y con DMO 7.9 gr/dl. Conclusiones: El RDW es de utilidad para medir la severidad de la sepsis según parámetros clínicos. Hay correlación entre el aumento del RDW y el APACHE II.

Sepse é uma síndrome, na qual, o paciente apresenta lesões de órgãos com risco a vida, em decorrência de uma inflamação exagerada desencadeada por uma infecção. Estima-se uma ocorrência anual de 31,5 milhões de casos de sepse e 19,4 milhões de casos de choque séptico no mundo, causando potencialmente 5,3 milhões de mortes. Esses índices alarmantes fizeram com que em 2017, a Organização Mundial da Saúde (OMS) adotasse uma resolução com o objetivo de aperfeiçoar a prevenção, diagnóstico e tratamento dessa condição clínica que vem sendo negligenciada. A iniciação da sepse, ocorre quando há um descontrole da infecção, acarretando excessiva ativação de células do sistema imune inato. Isso resulta em uma inflamação sistêmica danosa que é responsável pela maioria das alterações fisiopatológicas da sepse. Nesse contexto do sistema imune inato, o papel de neutrófilos já é bem compreendido da patogênese da sepse. Contudo, a função dos monócitos inflamatórios ainda não é bem estabelecida. Ao mesmo tempo que essas células podem participar do controle de infecções, elas também podem contribuir com a inflamação sistêmica e a lesão de órgãos. Deste modo, a compreensão do papel dessas células se faz importante para determinação de novos alvos terapêuticos para essa condição clínica. Nossos resultados demonstraram, em modelo experimental de sepse, que o aumento da emigração de monócitos inflamatórios da medula óssea está relacionado com maior taxa de mortalidade dos animais e exacerbação da inflamação sistêmica. A migração dessas células para órgãos, como rim e pulmão, está relacionado com inflamação e aumento de lesões, nesses locais. Deste modo, conclui-se que monócitos inflamatórios possuem um papel deletério na patogênese da sepse / Sepsis is a syndrome in which the patient has life-threatening organ damage due to an exaggerated inflammation triggered by an infection. The annual occurrence is 31.5 million cases of sepsis and 19.4 million cases of septic shock in the world, which potentially cause 5.3 million deaths. In concern of these alarming reports in 2017, the World Health Organization (WHO) adopted a resolution aimed at improving the prevention, diagnosis and treatment of this neglected clinical condition. The initiation of sepsis occurs when the infection was not controlled, causing excessive activation of the innate immune cells. This excessive activation causes a systemic inflammation that is responsible for most pathophysiological phenomena in sepsis. In this context of the innate immune system, the role of neutrophils is already well understood in the pathogenesis of sepsis. However, the role of inflammatory monocytes is not yet well established. These cells can participate in the control of infections, or can also contribute to systemic inflammation and organs damage. Thus, the understanding of the roles of these cells become important for the development of new therapeutic targets for this clinical condition. Our results demonstrated that the systemic increase of the inflammatory monocytes frequency is related to higher mortality rate, exacerbation of systemic inflammation, increased migration to organs (lung and kidney), and in these sites, are related to inflammation and lesions. Thus, we concluded that these cells have a deleterious role in the pathogenesis of sepsis

Diese multizentrische, randomisierte, doppel-blinde Studie hatte zum Ziel, die additive Wirksamkeit von Pentaglobin® bei der Behandlung der Peritonitis zu untersuchen. Pentaglobin® wurde hierbei zusammen mit einer im klinischen Alltag üblichen Antibiotikatherapie intravenös verabreicht. Die Kontrollgruppe erhielt ein Placebo bestehend aus Humanalbumin. Primäre Endpunkte waren der postoperative kumulierte Summenwert der SIRS-Kriterien nach Bone bis zum 23. postoperativen Tag sowie der postoperative kumulierte Summenwert des SOFA-Score bis zum 28. postoperativen Tag. Ergebnisse wurden durch Anwendung verschiedener Scores überprüft. Insgesamt konnten 260 Patienten mit Peritonitis an 16 Studienzentren eingeschlossen werden. 258 Patienten kamen in die Safety-Analyse sowie 255 in die Intentio-To-Treat Analyse. Bei den primären Endpunkten konnte eine Tendenz für die Wirksamkeit von Pentaglobin® bei septischen Patienten gezeigt werden. Insbesondere die Patienten mit einem höheren MPI-Wert scheinen mehr von einer Therapie mit Pentaglobin® profitiert zu haben. Eine statistische Signifikanz konnte jedoch nicht nachgewiesen werden. Bei den sekundären Endpunkten zeigte sich eine statistisch signifikant kürzere Therapie mit Katecholaminen in der Pentaglobin®-Gruppe. Weiterhin fanden sich statistisch signifikante Unterschiede des IL-2-Rezeptors sowie des TNF-1-Rezeptors im Studienverlauf zwischen der Pentaglobin®- und der Placebo-Gruppe. Bei der Überprüfung der Verträglichkeit der Studienmedikation fanden sich keine signifikanten Unterschiede. / The aim of the present clinical trial was to show a therapeutic effect of Pentaglobin® under concomitant administration of antibiotics in patients with beginning peritoneal infections. The study was conducted as a placebo-controlled, double-blind, multicentre and prospective trial of clinical phase IV. The patients were allocated to the two treatment groups (Pentaglobin®/placebo) by randomisation. The primary efficacy parameters were the post-operative cumulative sum score of the SIRS criteria according to Bone until Day 23 and the post-operative cumulative Sequential Organ Failure Assessment (SOFA) sum score until Day 28. In total 260 patients with beginning intraabdominell infection in 16 study centres were included in the study. 258 patients were included in the safety analyses and 255 in the Intention-to-treat analyses. In conclusion, the efficacy results in this study showed a tendency in favour of Pentaglobin® compared to placebo regarding the primary efficacy parameters cumulative SIRS score and cumulative SOFA score that were lower in the Pentaglobin® group than in the placebo group, especially in patients with a more severe peritonitis. The differences between Pentaglobin® and placebo in SIRS and SOFA score were not statistically significant, but patients in the Pentaglobin® group had a lower mean TISS-28 score, a shorter duration of fever, a shorter duration of ICU treatment and artificial ventilation and the duration of treatment with catecholamines was significantly shorter in the Pentaglobin® group. Regarding laboratory parameters, the inflammatory parameters decreased more in the Pentaglobin® group than in the placebo group (with significant differences in favour of Pentaglobin® for IL-2R and TNF-R1) while the significant differences in favour of Pentaglobin® for IgM, IgA, IgG were mainly caused by the administration of the intravenous immunoglobulin preparation (with significant differences in favour of Pentaglobin® for IgM, IgA, IgG). The safety data showed that Pentaglobin® and placebo were equally safe and well tolerated.

Sepsis and its manifestation as a shock state in “septic shock” have long caused medical issues and death worldwide. The disease requires quick identification, diagnosis, and intervention with very high mortality rates prevalent otherwise. Historically this has been due to limited awareness of the disease and misclassification of its prevalence, severity, and incidence. Luckily in the past decade there has been increased interest and therefore resources devoted towards improving care and further understanding a disease that is one of the leading causes of mortality in hospitals worldwide. Over the past handful of years novel interventions and diagnostic techniques have become available. Unfortunately, in many cases these new discoveries have not yet trickled down to many of the providers on the frontline and a large amount of variation in care exists across the country. Because of the time sensitivity of sepsis, it is imperative that individuals working in the areas of healthcare who first come in contact with these patients have a clear understanding of the newest advances and resources available. In this thesis the goal is to first analyze the current protocols and standards of care for sepsis and then secondly consider new developments available both in the hospital and in prehospital emergency medical services (EMS). From the current information, strategies and protocols based on improvement of patient outcomes, can be streamlined and optimized moving forward. As predicted, there is currently an incredibly large amount of variation and knowledge on the subject with some areas implementing very progressive protocols while others still lack a sepsis protocol all together. In general, the current consensus in the field is that rapid identification and initiation of treatment is the most important component to long term survival. Improvement of outcomes therefore relies on standardization of protocols with incorporation of education components for healthcare providers. This aims to raise awareness and encourage utilization of the newest information and suggestions available. Increased interdisciplinary cooperation between prehospital providers in EMS and care providers in the hospital can also lead to improvement of recognition and treatment times for these patients. Future considerations were also examined that may potentially be applicable moving forward to improve these standards even further. There is a much opportunity available in each of these areas currently and progress is key to improving outcomes.

Pneumonia and sepsis are distinct but linked public health concerns. Each condition is the leading cause of the other; however, the responses controlling the susceptibility between the two disease processes remain speculative. The acute phase response (APR) is an important component of the host immune response during pneumonia and sepsis, and primarily driven by the activation of hepatocyte transcription factors NF-κB RelA and STAT3. While the NF-κB pathway is essential for inflammation and hepatocyte function, its inactivation has been associated with hepatotoxicity. Liver injury is an independent risk factor for sepsis morbidity and mortality, suggesting that pathways promoting liver homeostasis may limit the systemic consequences of pneumonia. To identify conditions in which NF-κB RelA is required for liver resilience, we challenged mice lacking hepatocyte RelA (hepRelAΔ/Δ) and wildtype (WT) controls with E. coli, K. pneumoniae, S. pneumoniae, LPS, or αGalCer to induce pneumonia, sepsis, and/or NKT cell activation. Severe hepatotoxicity was observed in hepRelAΔ/Δ mice in all conditions examined in association with apoptosis, which could be prevented by neutralization of TNFα. Lastly, these changes were associated with remodeling of the hepatic transcriptome, likely reflecting both the cause and consequence of hepatoxicity. We have previously shown that activation of STAT3 in hepatocytes limits pneumonia susceptibility during endotoxemia, but the mechanisms whereby this liver APR provides protection are unknown. Iron sequestration is a defense mechanism against bacterial infections, which require iron for growth. Based on previous observations that alveolar lining fluid is favorable for bacteria in the absence of liver STAT3, we investigated whether liver APR limits pneumonia susceptibility during sepsis by withholding iron to prevent bacterial outgrowth. WT mice or mice lacking hepatocyte STAT3 (hepSTAT3Δ/Δ) mice were challenged with endotoxemia followed by E. coli pneumonia, or cecal ligation and puncture (CLP). Induction of mRNA encoding several essential iron-regulating factors was ablated in hepSTAT3Δ/Δ mice after endotoxemia and pneumonia, and post CLP. Additionally, liver STAT3 activation significantly remodeled the pulmonary transcriptome during endotoxemia, which potentially represents other protective mechanisms. Taken together, these results suggest that hepatic APR is an important immunological interface modulating pneumonia and sepsis interaction and susceptibility.

A sepse é uma síndrome de resposta inflamatória sistêmica decorrente de um processo infeccioso, a qual acarreta alta taxa de mortalidade. Relatos da literatura tem demonstrado que pacientes e animais de experimentação que sobrevivem à sepse desenvolvem quadro de imunossupressão tardia, o qual contribui com a maior sucetibilidade destes a infecções secundárias. Nosso grupo demonstrou que as células T reguladoras (Tregs) participam ativamente do desenvolvimento desta imunossupressão. O Fator de Necrose Tumoral (TNF) é uma citocina pleotrópica responsável por diversas funções durante a resposta inflamatória, apresentando dois receptores responsáveis pelas suas atividades: o TNFR1 e o TNFR2. Foi demonstrando que o TNF exerce um importante papel na atividade de Tregs, induzindo a proliferação, estabilização do fenótipo e aumentando sua atividade imunossupressora, sugerindo que tais atividades sejam atribuidas ao TNFR2. Desta forma, nosso objetivo foi avaliar a participação dos receptores de TNF no desenvolvimento da imunossupressão pós-sepse. Para isso animais WT, TNFR1-/- e TNFR1/2 -/- foram submetidos à sepse grave, induzida por CLP e tratados com um suporte básico (reposição hidríca e antibioticoterapia). Inicialmente avaliamos a participação dos receptores de TNF na fase aguda da sepse. Demonstramos que nesta fase os receptores de TNF, principalmente TNFR1, apresentam um papel prejudicial na migração de neutrófilos, no controle do processo infeccioso e nas lesões de orgãos decorrentes da sepse. Posteriormente, os animais sobreviventes foram infectados com um dose subletal de L. pneumophila i.n 15 dias após a CLP. Avaliamos a participação dos receptores TNF na sucetibilidade à infecção secundária induzida por L. pneumophila em animais sobreviventes à sepse. Observamos que animais TNFR1-/- sobreviventes à sepse são mais suscetíveis, ao passo que animais TNFR1/2-/- sobreviventes à sepse são resitentes à infecção secundária em relação aos animais WT sobreviventes à sepse. Avaliamos então, a expansão de Tregs no baço destes animais sobreviventes à sepse e, observamos que animais TNFR1-/- apresentam aumento da expansão de Tregs, ao passo que os animais TNFR1/2-/- não apresentaram expansão de Tregs comparados ao WT. Observamos também que as Tregs apresentam maior densidade de receptores de TNF do que as células T convencionais e, que durante a sepse ocorre aumento da densidade destes receptores nas Tregs. Sugerimos então que possivelmente o TNFR1 seja um regulador negativo, enquanto o TNFR2 possa assumir um papel na regulação positiva na expansão de Tregs após a sepse, durante o desenvolvimento da imunossupressão. / Sepsis is a systemic inflammatory response syndrome resulting from infectious process, resulting in high mortality rate. It has been shown that septic mice and patients that survived from sepsis develop a late immunosuppression, which contributes to greater susceptibility to these secondary infections. Our group has shown that regulatory T cells (Tregs) actively participate in the development of this immunosuppression. The Tumor Necrosis Factor (TNF) is pleiotropic cytokine responsible for several processes in the inflammatory response. Two receptors are responsible for the various activities of TNF: TNFR1 and TNFR2. It have shown that TNF plays an important role in the activity of Tregs, inducing proliferation, stabilization of phenotype and increasing their immunosuppressive activity. The authors also suggested that these activities are TNFR2-mediated. Thus, our objective was to evaluate the role of TNF receptors in the acute phase of sepsis and also in the development of immunosuppression post-sepsis. For that, TNFR1-/ -, TNFR1/2 -/ - and WT mice were underwent to severe sepsis induced by CLP and treatment with basic support (hydration and antibiotics). Initially we evaluated the participation of TNF receptors in the acute phase of sepsis. We suggest that at this stage the TNF receptor, TNFR1 mainly exert a deleterious role in the migration of neutrophils in control of the infectious process and the tissue damage resulting from sepsis. In addition, the survivors from the septic event were intranasaly infected with L. pneumophila in the 15th day after sepsis induction. We evaluated the participation of these receptors in susceptibility to secondary infection induced by L. pneumophila in survivors from sepsis. Comparing the animals that survived from sepsis, we observed that TNFR1/2-/- , like WT mice, are not susceptible to the secondary infection, while TNFR1-/- survivors are more susceptible to it. We also observed that TNFR1-/ - animals show increased expansion of Tregs in the spleen, different of TNFR1/2-/- mice, that did not show expansion of Tregs compared to WT. We also observed Tregs have a higher density of receptors for TNF than conventional T cells, whereas during sepsis occurs increased expression of this receptor in Tregs. Altogether, the results suggest that TNFR1 is a negative regulator, whereas TNFR2 may play a role in the upregulation during expansion of Tregs, in development of sepsis-induced imunossupression.

Sepse bacteriana é a maior causa de morbimortalidade na faixa etária pediátrica e neonatal. A detecção precoce do quadro séptico é difícil, devido os sinais iniciais da doença serem inespecíficos. A possibilidade da existência de exame laboratorial capaz de identificar precocemente quadros sépticos melhoraria o prognóstico desses pacientes. Várias proteínas de fase aguda foram estudadas como marcadores de infecção sendo a proteína C reativa (PCR) a mais utilizada. A procalcitonina (PCT), um pró-hormônio, encontra-se elevado precocemente em quadros sépticos em crianças e adultos. Estudo prospectivo com 14 crianças submetidas à cirurgia cardíaca com circulação extra-corpórea (CEC), com dosagens seriadas de procalcitonina e proteína C reativa, serviram como modelo de resposta inflamatória sistêmica sem infecção com dosagens antes da CEC, após a CEC no primeiro, segundo e terceiro dia após cirurgia, enquanto 14 crianças com sepse/choque séptico dosagens seriadas de PCT e PCR foram obtidas sequencialmente antes do tratamento antibioticoterápico e a cada dia até o terceiro dia. Em crianças sépticas a PCT demonstrou ser superior a PCR como marcador de sepse assim como para diferenciar quadros inflamatórios sistêmicos. / Bacterial sepsis is a major cause of morbidity and mortality in neonates and children. Early detection of bacterial sepsis is difficult because the first signs of this disease may be minimal or nonspecific. The availability of a laboratory test to accurately and rapidly identify septic neonates and children would be of great value in improving the outcome of these patients. Several acute-phase proteins have been used for the diagnosis of bacterial sepsis and C reactive protein (CRP) is the usual marker. It has been reported that the concentration of procalcitonin (PCT), a pro-hormone, is markedly higher in children and adults with sepsis. In a prospective study, 14 children were enrolled after cardiac surgery with cardiopulmonary bypass (CPB), these group represent the non infected children with inflammatory response. Blood samples were obtained before CPB, after CPB, on the first, second and third day after surgery. Another group with 14 children with sepsis or septic shock were enrolled, and blood samples were obtained before antibiotic start, on the first, second and third days. In septic children PCT concentration is a better diagnostic marker of sepsis and to differentiate inflammatory response than CRP.

O conhecimento científico da doença meningocócica cresceu significativamente desde que a natureza epidêmica da enfermidade foi pioneiramente descrita por Vieusseux no começo do século dezenove. De fato, dois séculos depois, houve avanços revolucionários nas esferas de saúde pública, técnicas diagnósticas, antibioticoterapia, assim como nas terapias adjuvantes envolvendo modulação das cascatas de coagulação e inflamação. Além disso, terapia de suporte para manter a homeostase via monitorização do status hemodinâmico, empregos de vasopressores, transfusão de plasma e suporte respiratório. Contudo, as taxas de letalidade e morbidade desta infecção não se alteraram significativamente nas últimas três décadas. Anualmente, a Organização Mundial de Saúde estima que ocorram 1.2 milhões de novos casos da doença, resultando em 135.000 mortes. No Brasil, anualmente, há 3500 casos da doença com uma taxa de incidência igual a 2 casos por 100.000 habitantes e uma taxa de letalidade igual a 20%. No Instituto de Infectologia Emílio Ribas (IIER) há 100 casos por ano. Assim, nós observamos um amplo espectro clínico da infecção, incluindo manifestações dramáticas como purpura fulminans e complicações atípicas como peritonite. O propósito deste estudo foi avaliar as características clínicas e laboratoriais, assim como a severidade da doença nos pacientes hospitalizados no IIER entre 2003 e 2004. Assim, pacientes previamente hígidos com diagnóstico de infecção meningocócica foram incluídos neste estudo prospectivo. Durante o período de estudo um total de 91 (53 homens e 38 mulheres) pacientes foram identificados como casos confirmados de infecção meningocócica como previamente descrito em materiais e métodos. Culturas de sangue, líquor, ou biópsia de pele de 39 pacientes (43%) foram positivas para N. meningitidis. Todos pacientes tiveram o exame de contraimunoeletroforese ou teste de aglutinação do látex positivo. A idade mediana dos pacientes foi igual a 6 anos (variação, 2 a 16 anos). A letalidade foi igual a 14% (13/91) e seqüelas ou complicações clínicas ocorreram em 63% (49/78) dos sobreviventes. Todos pacientes morreram de choque séptico e o tempo mediano entre hospitalização e óbito foi igual a 24 horas (variação, 18-72 horas). Concluindo, os resultados deste estudo prospectivo criam um elo entre infecção meningocócica e uma constelação de fenômenos fisiopatológicos: hipocalemia, hipomagnesemia, hipocalcemia, hiponatremia, hipoglicemia, hiperglicemia, leucopenia, coagulopatia e plaquetopenia. Os níveis de IL-6 e IL-10 corresponderam bem com a classificação baseada em parâmetros clínicos. A letalidade foi igual a 14% (13/91) e seqüelas ou complicações clínicas ocorreram em 63% (49/78) dos sobreviventes. Uma complexa interação entre mediadores é responsável por determinar a severidade da infecção e tais observações podem ser utilizadas para identificar fatores associados com a gravidade na fase aguda da infecção meningococócica / Scientific knowledge of meningococcal infection has increased greatly since the epidemic nature of the illness was first described by Vieusseux at the dawn of the nineteenth century. In fact, two centuries later, revolutionary advances have been made in public health measures, diagnostic procedures, antimicrobial therapy, and adjunctive therapies involving modulation of the inflammatory and coagulation cascades. In addition, supportive care facilities can maintain homeostasis by monitoring hemodynamic status, administering vasoactive agents and/or plasma exchange, and providing respiratory support. However, the prognosis of and case fatality rate among patients affected by meningococcal disease have not changed significantly over the past 3 decades. The World Health Organization estimates that there are 1.2 million cases of meningococcal disease and 135,000 related deaths annually. In Brazil, 3500 cases are reported annually, with a median incidence of 2 cases per 100,000 population and a case-fatality rate of 20%. At the Emílio Ribas Institute of Infectology (ERII), the incidence of meningococcal disease is approximately 100 cases per year. Therefore, we have observed a broad range of clinical presentations of N. meningitidis infection, including dramatic manifestations as purpura fulminans and atypical complications such as peritonitis. The purpose of this study was to evaluate the clinical features, laboratory features, and the severity of meningococcal disease in patients admitted to the ERII between 2003 and 2004. Therefore, consecutive previously healthy patients with a diagnosis of meningococcal disease were included in a prospective cohort study. During the study period a total of 91 (53 males and 38 females) patients were identified as confirmed cases of meningococcal infection as previously described in material and methods. Cultures of blood, CSF, or skin biopsy specimens from 39 patients (43%) yielded N. meningitidis. All patients had positive counterimmunoelectrophoresis or latex agglutination test in blood or CSF. The median age of the patients was 6 years (range, 2 years to 16 years). The case fatality rate was 14% (13/91) and sequelae or clinical complications occurred in 63% (49/78) of the survivors. All patients died of irreversible septic shock and the median duration from the hospitalization until death was 24 hours (range, 18-72 hours). In conclusion, results from this prospective cohort study support a link between meningococcal infection and a constellation of pathophysiological phenomena: hypokalemia, hypomagnesemia, hypocalcemia, hyponatremia, hypoglycemia, hyperglycemia, leukopenia, coagulopathy, and thrombocytopenia. Both pro-inflammatory IL-6 and anti-inflammatory IL-10 corresponded well with a classification based on clinical parameters. The case fatality rate was 14% (13/91) and sequelae or clinical complications occurred in 63% (49/78) of the survivors. A complex interplay of mediators is responsible for determining severity of disease and these observations can be used to identify factors associated with severity in the acute phase of meningococcal infection

O sistema nervoso central (SNC) é uma das primeiras regiões a ser acometida durante a sepse e choque séptico, o que contribui para o aumento da taxa de morbidade e mortalidade. Pacientes em choque séptico apresentam disfunção neuronal aguda, tais como o delírio, desorientação e coma. Em longo prazo, o dano cognitivo pode ocorrer ocasionando o comprometimento do aprendizado e formação de memória. Estudos demonstram que durante a resposta inflamatória sistêmica exacerbada, mediadores inflamatórios presentes na circulação sistêmica, são capazes de chegar ao SNC e ocasionar a ativação de células gliais, conduzindo a um estado de neuroinflamação. Nesse processo, algumas estruturas do SNC, tais como o hipocampo são mais vulneráveis à ação de espécies reativas de oxigênio (ERO), e a mediadores inflamatórios produzidos de forma excessiva durante a sepse. Neste contexto, a investigação de novas estratégias terapêuticas que sejam capazes de atenuar a resposta inflamatória exacerbada se faz necessário. Assim, o presente projeto teve como objetivo investigar prováveis propriedades antioxidante e anti-inflamatória do Hidrogênio molecular (H2), bem como sua possível ação neuroprotetora em ratos submetidos à sepse polimicrobiana, induzida por ligadura e perfuração cecal (CLP). Para isso o projeto foi dividido em dois protocolos experimentais. No primeiro protocolo ratos Wistar submetidos à cirurgia de CLP ou Sham, foram submetidos ao tratamento com inalação do H2 a 2%, por um período de 1h durante 10 dias consecutivos, e logo após foram submetidos a testes comportamentais para avaliação da memória de habituação, discriminativa e aversiva. No segundo protocolo os animais foram tratados com inalação do H2 por um período de 3h, e 24h após ao término da cirurgia de CLP/Sham foram decapitados para coleta do sangue e cérebro. A partir dos resultados dos testes comportamentais observamos que o tratamento com inalação do H2 durante a sepse experimental preveniu a perda de memória e o dano cognitivo, bem como foi capaz de diminuir os níveis de citocinas pró-inflamatórias de fase aguda tais como IL-1?, IL-6 e TNF? no córtex pré-frontal e hipocampo. A estratégia também foi capaz de diminuir os níveis de TBARS no plasma. Observamos um aumento da concentração da enzima catalase nos animais tratados com H2. Em conjunto os resultados indicam que o H2 foi capaz de inibir a resposta inflamatória e prevenir o dano cognitivo, agindo como uma substância neuroprotetora em ratos submetidos ao choque séptico experimental / The central nervous system is one of the first regions to be affected during Sepsis and septic shock, which contributes to the increased rate of morbidity and mortality. Patients with severe sepsis may present acute neuronal dysfunction such as delirium, disorientation, and unconscious. In the long term, cognitive damage can occur causing the commitment of learning and memory formation. Studies show that during the exacerbated systemic inflammatory response, inflammatory mediators present in the systemic circulation, are able to reach the CNS and cause the activation of glial cells, leading to a state of neuroinflammation. In this process, some CNS structures such as the hippocampus are more vulnerable to the action of reactive oxygen species (ROS), and to inflammatory mediators produced excessively during sepsis. In this context, the investigation of new therapeutic strategies that are capable of attenuating the exacerbated inflammatory response is necessary. Thus, the present project aimed to investigate the probable antioxidant and anti-inflammatory properties of molecular hydrogen (H2), as well as its possible neuroprotective action in rats submitted to polymicrobial sepsis induced by ligature and cecal puncture (CLP). In order to check this hypothesis, the project was divided into two experimental protocols. In the first protocol Wistar rats submitted to CLP or Sham surgery were submitted to 2% H2 inhalation treatment for a period of 1h for 10 consecutive days, and soon after they underwent behavioral tests to evaluate habituation memory, discriminative and aversive. In the second protocol the animals were treated with H2 inhalation for a period of 3h and 24h, and at the end of the treatment, they were decapitated for blood and brain collection. Plasma was already used for nitrate dosage, lipid peroxidation, antioxidant enzymes and inflammatory cytokines. From the results of the behavioral tests, we observed that treatment with H2 inhalation during the experimental sepsis prevented memory loss and cognitive damage, and was able to decrease the levels of acute-phase inflammatory cytokines such as IL-1?, IL -6 and TNF? in the prefrontal cortex and hippocampus. The therapeutic strategy was also able to decrease plasma TBARS levels. We also observed an increase in the concentration of the enzyme catalase in H2-treated animals. Together the results indicate that molecular hydrogen was able to inhibit the inflammatory response and prevent cognitive damage, acting as a neuroprotective substance, in rats submitted to experimental septic shock

A sepse é uma resposta inflamatória sistêmica resultante da inabilidade do sistema imune em controlar uma infecção, onde a taxa de sobrevida está associada ao recrutamento de neutrófilos para o local da infecção. Tem sido demonstrado que a expressão de receptores quimiotáticos pode ser alterada durante a sepse. Neutrófilos de animais naives respondem às quimiocinas CXC, mas são irresponsivos às quimiocinas CC. Entretanto, dados do nosso laboratório mostram que a expressão de CXCR2 é reduzida na sepse, prejudicando a migração de neutrófilos para o foco da infecção. Além disso, ocorre o aparecimento do receptor CCR2 nos neutrófilos, levando à infiltração dessas células no pulmão e outros órgãos. Nesse contexto, o nosso objetivo foi investigar a possível expressão do receptor CCR5 em neutrófilos e seu papel na evolução da sepse. Demostramos que animais sham-operados expressam baixos níveis de CCR5 e altos níveis de CXCR2. Entretanto, sob a condição de sepse experimental induzida por ligação e perfuração do ceco (CLP), neutrófilos circulantes e que migraram para a cavidade peritoneal expressam altos níveis de CCR5 em paralelo com a internalização de CXCR2. Além disso, animais deficientes para CCR5 (CCR5-/-), submetidos à CLP, apresentam diminuição na taxa de sobrevida, redução na migração de neutrófilos para o foco da infecção, aumento da disseminação bacteriana, aumento no infiltrado de neutrófilos no pulmão e aumento nos níveis de marcadores de lesão do coração e rim, quando comparados com animais selvagens (WT). Adicionalmente, a incubação de neutrófilos isolados da medula óssea com LPS aumentou a expressão de CCR5 e os tornou responsivos à MIP-1? (ligante de CCR5), induzindo quimiotaxia. Também demonstramos que o receptor CCR5 possui importante papel durante a adesão de neutrófilos ao endotélio vascular para posterior migração. Em conjunto, esses resultados indicam que durante a CLP, o aumento da expressão de CCR5 em neutrófilos tem um papel protetor, visto que animais CCR5-/- sépticos apresentam reduzida migração de neutrófilos para o foco infeccioso, inflamação sistêmica acentuada e baixa taxa de sobrevivência. / Sepsis is a systemic inflammatory response resulted from the inability of the innate immune system to control infections, being the survival rate associated to the recruitment of neutrophils to the infection site. It has been demonstrated that chemokine receptors expression profile can be altered under sepsis conditions. Neutrophils from naïve mice respond to CXC chemokines, but are usually unresponsive to CC chemokines. However, data from our laboratory show that CXCR2 expression is down regulated, impairing the neutrophil migration to infection focus. In addition, CCR2 appears on the surface of neutrophils, mediating the accumulation of these cells in the lung and other organs. In this context, we aimed to investigate the possible expression of CCR5 receptor on neutrophils and its role on sepsis evolution. We showed that neutrophils from sham mice express high levels of CXCR2 and low levels of CCR5. However, during experimental sepsis, induced by cecal ligation and puncture (CLP), in parallel with CXCR2 internalization, neutrophils from the circulation or from the peritoneal cavity express higher levels of CCR5. Interestingly, deficient mice for the CCR5 receptor (CCR5-/-), undergone to CLP show decreased survival rate, reduction in the neutrophil migration to the site of infection, increase in the numbers of bacteria, increase in the neutrophil infiltration in lung and heart and increase in the levels of markers of injuries in heart and kidney, when compared to wild type mice (WT).In addition, the incubation of bone marrow derivedneutrophils with LPS enhances the expression of CCR5 and renders them responsive to CCL4 (a ligant of CCR5)-induced chemotaxis. Moreover, we demonstrated that CCR5 receptor has an important role during neutrophil adhesion to the vascular endothelium before transmigration. Together, these results indicate that during CLP-induced sepsis, the increase of the expression of CCR5 on neutrophils plays a host protective role, since CCR5-/- mice under sepsis present reduced neutrophil migration to infection focus, high systemic inflammation and low survival rate.