Les immunoglobulines intraveineuses (IVIg) constituent une préparation polyclonale d’IgG isolée et regroupée à partir du plasma sanguin de multiples donneurs. Initialement utilisé comme traitement de remplacement chez les patients souffrant d’immunodéficience primaire ou secondaire, les IVIg sont maintenant largement utilisées dans le traitement de plusieurs conditions auto-immunes, allergiques ou inflammatoires à une dose élevée, dite immunomodulatrice. Différents mécanismes d’action ont été postulés au fil des années pour expliquer l’effet thérapeutique des IVIg dans les maladies auto-immunes et inflammatoires. Entre autre, un nombre grandissant de données issues de modèles expérimentaux chez l’animal et l’humain suggère que les IVIg induisent l’expansion et augmentent l’action suppressive des cellules T régulatrices (Tregs), par un mécanisme qui demeure encore inconnu. Également, les patients atteints de maladies auto-immunes ou inflammatoires présentent souvent un nombre abaissé de Tregs par rapport aux individus sains. Ainsi, une meilleure compréhension des mécanismes par lesquels les IVIg modulent les cellules T régulatrices est requise afin de permettre un usage plus rationnel de ce produit sanguin en tant qu’alternative thérapeutique dans le traitement des maladies auto-immunes et inflammatoires. Par le biais d’un modèle expérimental d’allergie respiratoire induite par un allergène, nous avons démontré que les IVIg diminuaient significativement l’inflammation au niveau des voies aériennes ce, en association avec une différenciation des Tregs à partir des cellules T non régulatrices du tissu pulmonaire. Nous avons également démontré qu’au sein de notre modèle expérimental, l’effet anti-inflammatoire des IVIg était dépendant des cellules dendritiques CD11c+ (CDs) pulmonaires, puisque cet effet pouvait être complètement reproduit par le transfert adoptif de CDs provenant de souris préalablement traitées par les IVIg. À cet effet, il est déjà établi que les IVIg peuvent moduler l’activation et les propriétés des CDs pour favoriser la tolérance immunitaire et que ces cellules seraient cruciales pour l’induction périphérique des Tregs. C’est pourquoi, nous avons cherché à mieux comprendre comment les IVIg exercent leur effet sur ces cellules. Pour la première fois, nous avons démontré que la fraction d’IgG riche en acide sialique (SA-IVIg) (constituant 2-5% de l’ensemble des IgG des donneurs) interagit avec un récepteur dendritique inhibiteur de type lectine C (DCIR) et active une cascade de signalement intracellulaire initiée par la phosphorylation du motif ITIM qui est responsable des changements observés en faveur de la tolérance immunitaire auprès des cellules dendritiques et des Tregs. L’activité anti-inflammatoire de la composante SA-IVIg a déjà été décrite dans des études antérieures, mais encore une fois le mécanisme par lequel ce traitement modifie la fonction des CDs n’a pas été établi. Nous avons finalement démontré que le récepteur DCIR facilite l’internalisation des molécules d’IgG liées au récepteur et que cette étape est cruciale pour permettre l’induction périphérique des Tregs. En tant que produit sanguin, les IVIg constitue un traitement précieux qui existe en quantité limitée. La caractérisation des mécanismes d’action des IVIg permettra une meilleure utilisation de ce traitement dans un vaste éventail de pathologies auto-immunes et inflammatoires. / Intravenous immunoglobulin (IVIg) is a therapeutic preparation of normal human polyclonal IgG derived from pooled plasma from a large number of healthy donors. Initially used as replacement therapy for patients with primary and secondary immune deficiencies, IVIg is now also widely used for the treatment of a variety of autoimmune, allergic and systemic inflammatory disorders, at high immunomodulatory doses. The beneficial effect of IVIg in autoimmune and inflammatory diseases has been attributed to different mechanisms. Increasing evidence shows that IVIg induces expansion and enhances the suppressive function of regulatory T cells (Tregs) in different experimental animal models and human subjects, through an unknown mechanism. Human inflammatory and autoimmune diseases are known to be associated with Treg deficiency. Therefore, a more precise understanding of the mechanisms by which IVIg modulate Treg populations seems to be needed for more rational use of this compound as an alternative therapy in context of various inflammatory and autoimmune disorders. Using a robust antigen-driven model of allergic airway disease, we have demonstrated that IVIg markedly attenuates airway inflammation and this effect is associated with the induction of Tregs from non-regulatory T cells in pulmonary tissues. We have also demonstrated that the antiinflammatory actions of IVIg, in our model are dependent on a population of pulmonary CD11c+ dendritic cells (DCs), as the action of IVIg could be completely replicated by adoptive transfer of CD11c+ DCs from IVIg-treated mice. we have shown that tolerogenic DCs involve in the peripheral induction of Tregs. Given the requirement of DCs in the induction of Tregs, we explored the mechanism by which IVIg interacts and modulate these cells and for the first time demonstrated that the purified sialylated fraction of human IgG (SA-IVIg) (that consists 2-5% of whole IgG) interacts with an inhibitory C-type lectin receptor on dendritic (DCIR) and this interaction triggers an ITIM intracellular signaling cascade. This subsequently results in rendering tolerogenic activities to DCs and peripheral induction of Tregs. The anti-inflammatory activity of SA-IVIg has been shown in previous studies, but the mechanism by which it modulates DCs functions is not well understood. We also demonstrated that DCIR facilitates the internalization of IgG molecules into DC and this internalization appears to be a crucial step for induction of Tregs. IVIg is a costly therapeutic compound. Characterization of the mechanism of action of IVIg can lead to a better application of this plasma based therapy in a wide range of autoimmune and inflammatory diseases.

Por apresentarem mecanismos de transmissão superponíveis, a infecção concomitante pelo vírus da hepatite C (VHC) e pelos vírus linfotrópicos de células T humanas dos tipos 1 (HTLV-1) e 2 (HTLV-2) é esperada. Considerando a relevância dessas infecções em nosso meio e a existência de lacunas no conhecimento da coinfeção VHC/HTLV, conduziu-se este estudo transversal, com o objetivo de comparar uma série de pacientes coinfectados, com indivíduos infectados pelo VHC isoladamente, no tocante a características sócio-demográficas e de exposição aos agentes virais, alterações clínicas e laboratoriais, bem como alterações histológicas do parênquima hepático. Selecionaram-se, com base em algoritmos de diagnóstico sorológico e de biologia molecular, pacientes adultos assistidos em ambulatórios do Hospital das Clínicas da FMUSP entre janeiro de 1993 e agosto de 2005, que apresentaram viremia pelo VHC, associada, ou não, a infecção por HTLV-1 ou HTLV-2, excluindo-se da amostra os coinfectados pelo VHB ou HIV. Coletaram-se dos pacientes selecionados características sócio-demográficas, informações acerca de exposição a vírus de transmissão sexual ou sangüínea, sinais e sintomas clínicos relacionados às infecções causadas pelo VHC ou HTLV, bem como dados laboratoriais hematológicos e de função hepática. Procedeu-se ainda à revisão sistemática dos achados histopatológicos do parênquima hepático, seguindo-se a classificação de Ishak. Compararam-se, então, os grupos VHC, VHC/HTLV-1 e VHC/HTLV-2, empregando-se o teste de X2 para as variáveis categóricas e o teste de Kruskal-Wallis para as variáveis contínuas. Em seguida, pela análise discriminante linear de Fischer, definiram-se funções classificatórias com variáveis que conjuntamente diferenciassem os grupos estudados. Finalmente, a acurácia discriminatória das funções classificatórias foi avaliada por validação cruzada, empregando-se a técnica leave-one-out. Compuseram a população estudada 85 pacientes, sendo 55 no grupo VHC, 24 no grupo VHC/HTLV-1 e 6 no grupo VHC/HTLV-2. À análise bivariada, não se observou diferença significativa entre os grupos no tocante a características sócio-demográficas, hábito de fumar, fatores de exposição às infecções virais, tais como transfusão sangüínea, tatuagem, acupuntura, ou número de parceiros sexuais. Ao contrário, o relato de uso de álcool, drogas endovenosas, ou cocaína inalatória, bem como a parceria sexual com UDEV foi mais freqüente entre os pacientes do grupo VHC/HTLV-2, enquanto o relato de parceiro sexual com hepatite predominou no grupo VHC. Do ponto de vista clínico, apenas a queixa de dor abdominal apresentou-se em freqüência significativamente diferente entre os grupos, sendo mais prevalente no grupo VHC. Em relação aos achados laboratoriais, apesar de contida nos intervalos de normalidade, houve diferença significativa na contagem de plaquetas em sangue periférico, com valores medianos mais elevados nos grupos de coinfectados. As concentrações séricas de aminotransferases e de GGT foram mais altas no grupo VHC. Apesar de freqüentemente encontradas alterações sugestivas de hepatopatia pelo VHC, como fibrose hepática e atividade necroinflamatória, a análise histopatológica não mostrou diferença significativa entre os grupos. À análise discriminante de Fischer, definiram-se funções classificatórias que melhor diferenciam os pacientes estudados, incluindo as variáveis sexo, faixa etária, relato de uso de drogas endovenosas e parceria sexual com indivíduo com hepatite. Por meio de validação cruzada, verificou-se que a acurácia discriminante das funções classificatórias foi alta (87,3%) para a identificação dos infectados pelo VHC isoladamente e intermediária (66,7%) para os coinfectados VHC/HTLV-2. O método não se mostrou, contudo, clinicamente útil na distinção de pacientes com coinfecção VHC/HTLV-1. / Co-infection with hepatitis C virus (HCV) and human T-lymphotropic virus types 1 (HTLV-1) and 2 (HTLV-2) is expected, as these viruses share common infection routes. Due to the relevance of these viral infections in Brazil and the existing gaps in knowledge about HCV/HTLV co-infection, we carried out this cross-sectional survey. A cohort of co-infected patients was compared to HCV-infected subjects, in regard to socio-demographic features, risk factors for viral acquisition, clinical and laboratory data, as well as liver histopathologic findings. Based on established serologic and molecular diagnostic algorithms, we selected HCV-viremic adult patients who attended the Hospital das Clínicas-FMUSP outpatient clinic from January 1993 to August 2005, whether or not they presented co-infection with HTLV-1 or HTLV-2. HBV and HIV-infected individuals were excluded from the sample. We collected patients\' sociodemographic characteristics, risk of exposure to blood-borne or sexually-transmitted viral agents, signs and symptoms related to HCV or HTLV disease, as well as laboratory data that included hematologic counts and liver function tests. Histopathologic findings were systematically reviewed, in accordance to the Ishak\'s scoring system. Patients from the HCV, HCV/HTLV-1 and HCV/HTLV-2 groups, were then compared by means of the X2 or Kruskal-Wallis tests for categorical or continuous variables, respectively. In addition, Fischer\'s linear discriminant analysis was applied to define classification functions that better identified the combined effect of variables important for discrimination of the study groups. Finally, the discriminating accuracy of the model was evaluated by cross-validation, using the leave-one-out technique. The study sample comprised 85 patients, 55 in the HCV group, 24 in the HCV/HTLV-1 group and 6 in the HCV/HTLV-2 group. In bivariable analysis, no significant difference was found among groups in regard to socio-demographic features, smoking, risk factors for viral acquisition, such as blood transfusion, tattooing, acupuncture, or number of sexual partners. In contrast, alcohol consumption, use of intravenous drugs or inhaled cocaine and sexual partnership with an intravenous drug user were more frequent in the HCV/HTLV-2 group, whereas patients in the HCV group more often reported a sexual partner with hepatitis. As far as clinical data are concerned, abdominal pain was the only variable to be reported differently, being more prevalent in the HCV group. Even though within normal ranges, co-infected patients presented higher median platelet counts, whereas aminotransferase and GGT levels were higher among HCV-infected subjects. No significant difference was seen in liver histopathologic findings, though HCV liver disease-associated abnormalities, such as fibrosis and necroinflammatory activity were often found in patients from the three groups. Classification functions, defined by discriminating analysis included as relevant variables sex, age, intravenous drug use and sexual partner with hepatitis. Cross-validation yielded high (87.3%) and intermediate (66,7%) discriminating accuracies for the HCV and HCV/HTLV-2 functions. However, this method was not shown clinically useful to distinguish HCV/HTLV-1 co-infected patients.

Fragestellung: Es wird untersucht, ob die isolierte hypertherme Extremitätenperfusion (ILP) mit TNF-alpha und Melphalan eine akute systemische inflammatorische Reaktion (SIRS) auslöst. Weiterhin soll der Einfluß von zwei verschiedenen total intravenösen Narkoseverfahren sowie der Zusammenhang der unabhängig voneinander bestimmten Meßgrößen Herzindex/Sauerstoffverbrauchsindex (HI/VO2I) und Sauerstoffverbrauchsindex/Sauerstoffangebotsindex (VO2I/DO2I) beim Entstehen eines SIRS analysiert werden. Methodik: 73 Patienten, die sich einer ILP mit TNF-alpha und Melphalan in Allgemeinanästhesie unterzogen, wurden in diese klinische, retrospektive Untersuchung eingeschlossen. Ein erweitertes kardiopulmonales Monitoring, bestehend aus kontinuierlicher Thermodilution, kontinuierlicher indirekter Kalorimetrie, invasiver Blutdruckmessung sowie arterieller und gemischtvenöser Blutgasanalysen ermöglichte die Analyse von hämodynamischen, metabolischen und gasanalytischen Parametern an 8 definierten Zeitpunkten im Verlauf der ILP mit TNF-alpha und Melphalan. 21 Patienten erhielten eine Narkose mit Etomidate/Midazolam/Sufentanil/Pancuroniumbromid (N1), und bei 52 Patienten wurde die Narkose mit Propofol/Remifentanil/Cis-Atracurium (N2) durchgeführt. Ergebnisse: Während der ILP mit TNF-alpha und Melphalan kam es bei folgenden Parametern zu signifikanten Veränderungen in der systemischen Reperfusionsphase gegenüber den Ausgangswerten vor der extrakorporalen Zirkulation: Herzfrequenz, Herzindex, Temperatur, Gesamtsauerstoffaufnahme, pulmonale Sauerstoffaufnahme, Sauerstoffangebot, systemischer Gefäßwiderstand, pulmonalarterieller Mitteldruck, kardiale Füllungsdrücke, gemischtvenöser Kohlendioxid- und Sauerstoffpartialdruck, arterieller Kohlendioxid- und Sauerstoffpartialdruck, gemischtvenöse Sauerstoffsättigung, arterieller und gemischtvenöser Sauerstoffgehalt sowie arterieller pH- und Laktatwert. Bezüglich der Narkoseverfahren zeigte die Narkose N2 versus N1 signifikant geringere Herzfrequenzen und Herzindices, sowie signifikant erhöhte pulmonalarterielle Mitteldrücke, pulmonale und systemische Gefäßwiderstände. Die Korrelationen von HI/VO2I und VO2I/DO2I sind in der prä-Bypass-Phase gering, nehmen im Verlauf der ILP zu und erreichen zum Zeitpunkt der systemischen Reperfusion jeweils ihren Maximalwert. Schlußfolgerungen: Die ILP mit TNF-alpha und Melphalan kann als dynamisches in-vivo Modell für das Entstehen einer SIRS-Reaktion aufgefaßt werden. Die inflammatorische Antwort ist in ihrem Ausmaß eher gering und erreicht nach Aufhebung der extrakorporalen Zirkulation mit systemischer Reperfusion der behandelten Extremität ihr Maximum. Die Überwachung der Teilkreisläufe, ein erweitertes hämodynamisches Monitoring sowie forcierte intravenöse Volumentherapie in der Reperfusionsphase lassen dieses Behandlungsverfahren für die Patienten in Allgemeinanästhesie sicher erscheinen. Beide beschriebenen Narkoseverfahren sind für diese operative Therapie geeignet. Der Zusammenhang von HI/VO2I sowie VO2I/DO2I ist im Verlauf der ILP gering, kann sich aber mit Zunahme der inflammatorischen Reaktion verstärken. / objective: To determine whether the isolated hyperthermic limb perfusion (ILP) with tumor necrosis factor alpha (TNF-alpha) and melphalan causes an acute systemic inflammatory response syndrome (SIRS)? Also analysed will be the influence of two total intravenous anaesthesias and the correlation of independent measured values cardiac index/oxygen consumption index (HI/VO2I) and oxygen consumption index/oxygen delivery index (VO2I/DO2I). design: Retrospective review of hemodynamic, metabolic and blood gas values from 73 patients, undervented isolated hyperthermic limb perfusion of leg with TNF-alpha and Melphalan in general anaesthesia. methods: Cardiopulmonary monitoring consisted of continuous thermodilution, continuous calorimetry, arterial pressure and arterial as well as admixed blood-gas analyses. Values were measured on 8 time points in the course of ILP. In 21 patients anaesthesia was carried out with drug-combination of Etomidate/Midazolam/Sufentanil/Pancuroniumbromid (N1), and 52 patients were given anaesthesia with Propofol/Remifentanil/Cis-atracurium (N2). results: The following values changed significantly after limb-reperfusion compared with the baseline: heart rate, cardiac index, temperature, oxygen consumption, pulmonary oxygen consumption, oxygen delivery, systemic vascular resistance, mean pulmonary arterial pressure, precardial pressures, admixed carbon dioxide pressure, admixed oxygen pressure, arterial carbon dioxide pressure, arterial oxygen pressure, admixed oxygen saturation, arterial and admixed oxygen content as well as arterial pH- and lactat. conclusions: The isolated hyperthermic limb perfusion with TNF-alpha and melphalan may be used as a dynamic in-vivo model for the development of an SIRS. The inflammatory response is slight and reached the maximum after reperfusion of treated limb. Monitoring of the two circulations, extended cardiopulmonary monitoring and intravenous volumetherapie in the reperfusion time makes this cancer treatment in general anaesthesia safe. Both anaesthesia are suitable. The correlations of HI/VO2I as well as VO2I/DO2I are low in the beginning and rise with the increase of the inflammatory response.

A administração intravenosa de solução salina hipertônica (HSS) induz alterações sistêmicas circulatórias como o aumento da pressão arterial e do volume circulante efetivo, além de ter efeitos locais sobre a microcirculação. No presente estudo foram analisados os efeitos produzidos pela administração de solução salina hipertônica 7,5% sobre a hemodinâmica do tumor através de estudos de imagem funcional e posteriormente, foi avaliado o seu potencial de otimizar a entrega de moléculas no tumor. A velocidade do sangue nos vasos tumorais estimada por Ultrassom Color Doppler foi aumentada após a injeção da HSS em comparação ao controle PBS em tumores de melanoma (B16F10 (p=0,019), SK-MEL-147 (p =0,028)) e de mama (4T1 (p=0,015)). Este mesmo efeito não foi observado nas artérias segmentarias do rim (p=0,476). Ultrassonografia com contraste por microbolhas (CEUS) foi realizada em xenoenxertos de tumor de melanoma (B16F10), carcinoma de cólon (HCT-116) e mama (MDA-MB-231), e como controle foi realizada imagem no rim e no músculo nos animais portadores destes tipos tumorais (n=3 por grupo). Após a injeção da HSS, o volume relativo de sangue foi aumentado nos tumores B16F10 (p=0,022) e HCT-116 (P = 0,039), mas o mesmo não foi observado com o tumor MDA-MB-231 (p=0,186). Além disso, não houve alterações nos tecidos normais (rim p = 0,957; músculo p = 0,104). Todos os testes estatísticos foram bicaudais. Quando a HSS foi utilizada como veículo para entrega de moléculas de baixo peso molecular como cisplatina e doxorrubicina no tratamento de tumores B16F10 e 4T1 respectivamente, não houve aumento da eficácia terapêutica, avaliada através do crescimento tumoral e peso dos tumores. O efeito da HSS sobre a retenção de macromoléculas nos tumores SK-Mel- 147 e 4T1, avaliado através de imagem por epifluorescência do contraste ótico IR-783, não foi suficientemente notório para rejeitar a hipótese nula. Assim, a HSS induz um aumento transitório na velocidade do sangue e do volume sanguíneo, de maneira relativamente seletiva para os tumores avaliados, com exceção do MDA-MB-231. Portanto, esta pode ser uma estratégia útil para aumentar a entrega de moléculas e otimizar tanto o efeito terapêutico, quanto o diagnóstico por imagem / Intravenous administration of Hypertonic saline solution (HSS) induces systemic circulatory changes including blood pressure rising, effective circulating volume increase as well as local effects on microvasculature. We analyzed the effects produced by Hypertonic Saline 7,5% administration on tumor hemodynamics through functional imaging studies as well as whether it enhances molecular delivery in tumor tissue when used as a vehicle. Blood velocity assessed by Color Doppler Ultrasound was increased after HSS injection compared to PBS in the following tumors: B16F10 (p=0,019), SKMEL- 147 (p=0,028) and 4T1 (p=0,015). No statistical difference was observed on the segmental kidney arteries (p=0,476). Dynamic Contrast enhanced ultrasound (CEUS) was done in B16F10, HCT-116 and MDA-MB-231 tumor xenografts, kidney and muscle tissues (n=3 per group). After HSS injection, relative blood volume was increased in B16F10 (p=0,022) and HCT-116 (p=0,039) but not on MDA-MB-231 (p=0,186). Changes on normal tissues were not statistically different (kidney p=0,957; muscle p=0,104). All statistical tests were two-sided. Administration of HSS as a vehicle for low molecular weight molecules cisplatin and doxorubicin in the treatment of B16F10 and 4T1 tumors respectively had no significant improvement of therapeutic efficacy, estimated by tumor growth and tumor weight measurements. Effect of HSS over retention of macromolecules in tumors SK-Mel-147 and 4T1, evaluated by epifluorescence imaging of the optical contrast IR- 783 was not large enough to reject the null hypothesis. HSS induces a transient increase in velocity of the blood as well as the blood volume that is relatively selective for the evaluated tumors with exception of MDA-MB-231. Data suggest that HSS administration might be a useful strategy to increase the delivery of molecules and optimize both therapy and diagnostic imaging

Por apresentarem mecanismos de transmissão superponíveis, a infecção concomitante pelo vírus da hepatite C (VHC) e pelos vírus linfotrópicos de células T humanas dos tipos 1 (HTLV-1) e 2 (HTLV-2) é esperada. Considerando a relevância dessas infecções em nosso meio e a existência de lacunas no conhecimento da coinfeção VHC/HTLV, conduziu-se este estudo transversal, com o objetivo de comparar uma série de pacientes coinfectados, com indivíduos infectados pelo VHC isoladamente, no tocante a características sócio-demográficas e de exposição aos agentes virais, alterações clínicas e laboratoriais, bem como alterações histológicas do parênquima hepático. Selecionaram-se, com base em algoritmos de diagnóstico sorológico e de biologia molecular, pacientes adultos assistidos em ambulatórios do Hospital das Clínicas da FMUSP entre janeiro de 1993 e agosto de 2005, que apresentaram viremia pelo VHC, associada, ou não, a infecção por HTLV-1 ou HTLV-2, excluindo-se da amostra os coinfectados pelo VHB ou HIV. Coletaram-se dos pacientes selecionados características sócio-demográficas, informações acerca de exposição a vírus de transmissão sexual ou sangüínea, sinais e sintomas clínicos relacionados às infecções causadas pelo VHC ou HTLV, bem como dados laboratoriais hematológicos e de função hepática. Procedeu-se ainda à revisão sistemática dos achados histopatológicos do parênquima hepático, seguindo-se a classificação de Ishak. Compararam-se, então, os grupos VHC, VHC/HTLV-1 e VHC/HTLV-2, empregando-se o teste de X2 para as variáveis categóricas e o teste de Kruskal-Wallis para as variáveis contínuas. Em seguida, pela análise discriminante linear de Fischer, definiram-se funções classificatórias com variáveis que conjuntamente diferenciassem os grupos estudados. Finalmente, a acurácia discriminatória das funções classificatórias foi avaliada por validação cruzada, empregando-se a técnica leave-one-out. Compuseram a população estudada 85 pacientes, sendo 55 no grupo VHC, 24 no grupo VHC/HTLV-1 e 6 no grupo VHC/HTLV-2. À análise bivariada, não se observou diferença significativa entre os grupos no tocante a características sócio-demográficas, hábito de fumar, fatores de exposição às infecções virais, tais como transfusão sangüínea, tatuagem, acupuntura, ou número de parceiros sexuais. Ao contrário, o relato de uso de álcool, drogas endovenosas, ou cocaína inalatória, bem como a parceria sexual com UDEV foi mais freqüente entre os pacientes do grupo VHC/HTLV-2, enquanto o relato de parceiro sexual com hepatite predominou no grupo VHC. Do ponto de vista clínico, apenas a queixa de dor abdominal apresentou-se em freqüência significativamente diferente entre os grupos, sendo mais prevalente no grupo VHC. Em relação aos achados laboratoriais, apesar de contida nos intervalos de normalidade, houve diferença significativa na contagem de plaquetas em sangue periférico, com valores medianos mais elevados nos grupos de coinfectados. As concentrações séricas de aminotransferases e de GGT foram mais altas no grupo VHC. Apesar de freqüentemente encontradas alterações sugestivas de hepatopatia pelo VHC, como fibrose hepática e atividade necroinflamatória, a análise histopatológica não mostrou diferença significativa entre os grupos. À análise discriminante de Fischer, definiram-se funções classificatórias que melhor diferenciam os pacientes estudados, incluindo as variáveis sexo, faixa etária, relato de uso de drogas endovenosas e parceria sexual com indivíduo com hepatite. Por meio de validação cruzada, verificou-se que a acurácia discriminante das funções classificatórias foi alta (87,3%) para a identificação dos infectados pelo VHC isoladamente e intermediária (66,7%) para os coinfectados VHC/HTLV-2. O método não se mostrou, contudo, clinicamente útil na distinção de pacientes com coinfecção VHC/HTLV-1. / Co-infection with hepatitis C virus (HCV) and human T-lymphotropic virus types 1 (HTLV-1) and 2 (HTLV-2) is expected, as these viruses share common infection routes. Due to the relevance of these viral infections in Brazil and the existing gaps in knowledge about HCV/HTLV co-infection, we carried out this cross-sectional survey. A cohort of co-infected patients was compared to HCV-infected subjects, in regard to socio-demographic features, risk factors for viral acquisition, clinical and laboratory data, as well as liver histopathologic findings. Based on established serologic and molecular diagnostic algorithms, we selected HCV-viremic adult patients who attended the Hospital das Clínicas-FMUSP outpatient clinic from January 1993 to August 2005, whether or not they presented co-infection with HTLV-1 or HTLV-2. HBV and HIV-infected individuals were excluded from the sample. We collected patients\' sociodemographic characteristics, risk of exposure to blood-borne or sexually-transmitted viral agents, signs and symptoms related to HCV or HTLV disease, as well as laboratory data that included hematologic counts and liver function tests. Histopathologic findings were systematically reviewed, in accordance to the Ishak\'s scoring system. Patients from the HCV, HCV/HTLV-1 and HCV/HTLV-2 groups, were then compared by means of the X2 or Kruskal-Wallis tests for categorical or continuous variables, respectively. In addition, Fischer\'s linear discriminant analysis was applied to define classification functions that better identified the combined effect of variables important for discrimination of the study groups. Finally, the discriminating accuracy of the model was evaluated by cross-validation, using the leave-one-out technique. The study sample comprised 85 patients, 55 in the HCV group, 24 in the HCV/HTLV-1 group and 6 in the HCV/HTLV-2 group. In bivariable analysis, no significant difference was found among groups in regard to socio-demographic features, smoking, risk factors for viral acquisition, such as blood transfusion, tattooing, acupuncture, or number of sexual partners. In contrast, alcohol consumption, use of intravenous drugs or inhaled cocaine and sexual partnership with an intravenous drug user were more frequent in the HCV/HTLV-2 group, whereas patients in the HCV group more often reported a sexual partner with hepatitis. As far as clinical data are concerned, abdominal pain was the only variable to be reported differently, being more prevalent in the HCV group. Even though within normal ranges, co-infected patients presented higher median platelet counts, whereas aminotransferase and GGT levels were higher among HCV-infected subjects. No significant difference was seen in liver histopathologic findings, though HCV liver disease-associated abnormalities, such as fibrosis and necroinflammatory activity were often found in patients from the three groups. Classification functions, defined by discriminating analysis included as relevant variables sex, age, intravenous drug use and sexual partner with hepatitis. Cross-validation yielded high (87.3%) and intermediate (66,7%) discriminating accuracies for the HCV and HCV/HTLV-2 functions. However, this method was not shown clinically useful to distinguish HCV/HTLV-1 co-infected patients.

Les immunoglobulines intraveineuses (IVIg) constituent une préparation polyclonale d’IgG isolée et regroupée à partir du plasma sanguin de multiples donneurs. Initialement utilisé comme traitement de remplacement chez les patients souffrant d’immunodéficience primaire ou secondaire, les IVIg sont maintenant largement utilisées dans le traitement de plusieurs conditions auto-immunes, allergiques ou inflammatoires à une dose élevée, dite immunomodulatrice. Différents mécanismes d’action ont été postulés au fil des années pour expliquer l’effet thérapeutique des IVIg dans les maladies auto-immunes et inflammatoires. Entre autre, un nombre grandissant de données issues de modèles expérimentaux chez l’animal et l’humain suggère que les IVIg induisent l’expansion et augmentent l’action suppressive des cellules T régulatrices (Tregs), par un mécanisme qui demeure encore inconnu. Également, les patients atteints de maladies auto-immunes ou inflammatoires présentent souvent un nombre abaissé de Tregs par rapport aux individus sains. Ainsi, une meilleure compréhension des mécanismes par lesquels les IVIg modulent les cellules T régulatrices est requise afin de permettre un usage plus rationnel de ce produit sanguin en tant qu’alternative thérapeutique dans le traitement des maladies auto-immunes et inflammatoires. Par le biais d’un modèle expérimental d’allergie respiratoire induite par un allergène, nous avons démontré que les IVIg diminuaient significativement l’inflammation au niveau des voies aériennes ce, en association avec une différenciation des Tregs à partir des cellules T non régulatrices du tissu pulmonaire. Nous avons également démontré qu’au sein de notre modèle expérimental, l’effet anti-inflammatoire des IVIg était dépendant des cellules dendritiques CD11c+ (CDs) pulmonaires, puisque cet effet pouvait être complètement reproduit par le transfert adoptif de CDs provenant de souris préalablement traitées par les IVIg. À cet effet, il est déjà établi que les IVIg peuvent moduler l’activation et les propriétés des CDs pour favoriser la tolérance immunitaire et que ces cellules seraient cruciales pour l’induction périphérique des Tregs. C’est pourquoi, nous avons cherché à mieux comprendre comment les IVIg exercent leur effet sur ces cellules. Pour la première fois, nous avons démontré que la fraction d’IgG riche en acide sialique (SA-IVIg) (constituant 2-5% de l’ensemble des IgG des donneurs) interagit avec un récepteur dendritique inhibiteur de type lectine C (DCIR) et active une cascade de signalement intracellulaire initiée par la phosphorylation du motif ITIM qui est responsable des changements observés en faveur de la tolérance immunitaire auprès des cellules dendritiques et des Tregs. L’activité anti-inflammatoire de la composante SA-IVIg a déjà été décrite dans des études antérieures, mais encore une fois le mécanisme par lequel ce traitement modifie la fonction des CDs n’a pas été établi. Nous avons finalement démontré que le récepteur DCIR facilite l’internalisation des molécules d’IgG liées au récepteur et que cette étape est cruciale pour permettre l’induction périphérique des Tregs. En tant que produit sanguin, les IVIg constitue un traitement précieux qui existe en quantité limitée. La caractérisation des mécanismes d’action des IVIg permettra une meilleure utilisation de ce traitement dans un vaste éventail de pathologies auto-immunes et inflammatoires. / Intravenous immunoglobulin (IVIg) is a therapeutic preparation of normal human polyclonal IgG derived from pooled plasma from a large number of healthy donors. Initially used as replacement therapy for patients with primary and secondary immune deficiencies, IVIg is now also widely used for the treatment of a variety of autoimmune, allergic and systemic inflammatory disorders, at high immunomodulatory doses. The beneficial effect of IVIg in autoimmune and inflammatory diseases has been attributed to different mechanisms. Increasing evidence shows that IVIg induces expansion and enhances the suppressive function of regulatory T cells (Tregs) in different experimental animal models and human subjects, through an unknown mechanism. Human inflammatory and autoimmune diseases are known to be associated with Treg deficiency. Therefore, a more precise understanding of the mechanisms by which IVIg modulate Treg populations seems to be needed for more rational use of this compound as an alternative therapy in context of various inflammatory and autoimmune disorders. Using a robust antigen-driven model of allergic airway disease, we have demonstrated that IVIg markedly attenuates airway inflammation and this effect is associated with the induction of Tregs from non-regulatory T cells in pulmonary tissues. We have also demonstrated that the antiinflammatory actions of IVIg, in our model are dependent on a population of pulmonary CD11c+ dendritic cells (DCs), as the action of IVIg could be completely replicated by adoptive transfer of CD11c+ DCs from IVIg-treated mice. we have shown that tolerogenic DCs involve in the peripheral induction of Tregs. Given the requirement of DCs in the induction of Tregs, we explored the mechanism by which IVIg interacts and modulate these cells and for the first time demonstrated that the purified sialylated fraction of human IgG (SA-IVIg) (that consists 2-5% of whole IgG) interacts with an inhibitory C-type lectin receptor on dendritic (DCIR) and this interaction triggers an ITIM intracellular signaling cascade. This subsequently results in rendering tolerogenic activities to DCs and peripheral induction of Tregs. The anti-inflammatory activity of SA-IVIg has been shown in previous studies, but the mechanism by which it modulates DCs functions is not well understood. We also demonstrated that DCIR facilitates the internalization of IgG molecules into DC and this internalization appears to be a crucial step for induction of Tregs. IVIg is a costly therapeutic compound. Characterization of the mechanism of action of IVIg can lead to a better application of this plasma based therapy in a wide range of autoimmune and inflammatory diseases.

A administração intravenosa de solução salina hipertônica (HSS) induz alterações sistêmicas circulatórias como o aumento da pressão arterial e do volume circulante efetivo, além de ter efeitos locais sobre a microcirculação. No presente estudo foram analisados os efeitos produzidos pela administração de solução salina hipertônica 7,5% sobre a hemodinâmica do tumor através de estudos de imagem funcional e posteriormente, foi avaliado o seu potencial de otimizar a entrega de moléculas no tumor. A velocidade do sangue nos vasos tumorais estimada por Ultrassom Color Doppler foi aumentada após a injeção da HSS em comparação ao controle PBS em tumores de melanoma (B16F10 (p=0,019), SK-MEL-147 (p =0,028)) e de mama (4T1 (p=0,015)). Este mesmo efeito não foi observado nas artérias segmentarias do rim (p=0,476). Ultrassonografia com contraste por microbolhas (CEUS) foi realizada em xenoenxertos de tumor de melanoma (B16F10), carcinoma de cólon (HCT-116) e mama (MDA-MB-231), e como controle foi realizada imagem no rim e no músculo nos animais portadores destes tipos tumorais (n=3 por grupo). Após a injeção da HSS, o volume relativo de sangue foi aumentado nos tumores B16F10 (p=0,022) e HCT-116 (P = 0,039), mas o mesmo não foi observado com o tumor MDA-MB-231 (p=0,186). Além disso, não houve alterações nos tecidos normais (rim p = 0,957; músculo p = 0,104). Todos os testes estatísticos foram bicaudais. Quando a HSS foi utilizada como veículo para entrega de moléculas de baixo peso molecular como cisplatina e doxorrubicina no tratamento de tumores B16F10 e 4T1 respectivamente, não houve aumento da eficácia terapêutica, avaliada através do crescimento tumoral e peso dos tumores. O efeito da HSS sobre a retenção de macromoléculas nos tumores SK-Mel- 147 e 4T1, avaliado através de imagem por epifluorescência do contraste ótico IR-783, não foi suficientemente notório para rejeitar a hipótese nula. Assim, a HSS induz um aumento transitório na velocidade do sangue e do volume sanguíneo, de maneira relativamente seletiva para os tumores avaliados, com exceção do MDA-MB-231. Portanto, esta pode ser uma estratégia útil para aumentar a entrega de moléculas e otimizar tanto o efeito terapêutico, quanto o diagnóstico por imagem / Intravenous administration of Hypertonic saline solution (HSS) induces systemic circulatory changes including blood pressure rising, effective circulating volume increase as well as local effects on microvasculature. We analyzed the effects produced by Hypertonic Saline 7,5% administration on tumor hemodynamics through functional imaging studies as well as whether it enhances molecular delivery in tumor tissue when used as a vehicle. Blood velocity assessed by Color Doppler Ultrasound was increased after HSS injection compared to PBS in the following tumors: B16F10 (p=0,019), SKMEL- 147 (p=0,028) and 4T1 (p=0,015). No statistical difference was observed on the segmental kidney arteries (p=0,476). Dynamic Contrast enhanced ultrasound (CEUS) was done in B16F10, HCT-116 and MDA-MB-231 tumor xenografts, kidney and muscle tissues (n=3 per group). After HSS injection, relative blood volume was increased in B16F10 (p=0,022) and HCT-116 (p=0,039) but not on MDA-MB-231 (p=0,186). Changes on normal tissues were not statistically different (kidney p=0,957; muscle p=0,104). All statistical tests were two-sided. Administration of HSS as a vehicle for low molecular weight molecules cisplatin and doxorubicin in the treatment of B16F10 and 4T1 tumors respectively had no significant improvement of therapeutic efficacy, estimated by tumor growth and tumor weight measurements. Effect of HSS over retention of macromolecules in tumors SK-Mel-147 and 4T1, evaluated by epifluorescence imaging of the optical contrast IR- 783 was not large enough to reject the null hypothesis. HSS induces a transient increase in velocity of the blood as well as the blood volume that is relatively selective for the evaluated tumors with exception of MDA-MB-231. Data suggest that HSS administration might be a useful strategy to increase the delivery of molecules and optimize both therapy and diagnostic imaging

La prise volontaire de nicotine augmente l'excitabilité de la voie ILCx-BNST, entraînant une hyperactivité des neurones DA de l’ATV. Dans une première partie, l'objectif était d’étudier les neuroadaptations de la voie ILCx-BNST induites par l'auto-administration intraveineuse (AAIV) de nicotine. Les récepteurs cannabinoides CB1 contrôlent les propriétés renforçantes de la nicotine. Par conséquent, nous avons examiné le rôle des récepteurs CB1 du BNST. Nous montrons que l'acquisition de l’AAIV de nicotine est associée à une facilitation persistante de l'induction d’une potentialisation à long terme (LTP) CB1-dépendantes des synapses ILCx-BNST. La stimulation électrique du ILCx favorise également la persistance du comportement de recherche de nicotine pendant les périodes où la drogue n'est pas disponible. En outre, en utilisant la pharmacologie intra-BNST, nous montrons que la stimulation des récepteurs CB1 du BNST au cours de l’acquisition de lAAIV augmente la sensibilité aux stimuli associés à la nicotine. L’idée qu’il existe un appétit incontrôlable pour les aliments palatables, en dépit des conséquences négatives. Dans une seconde partie, notre projet a porté sur le rôle des neurones dopaminergiques (DA) de l’ATV dans la perception d’un stimulus aversif chez l’animal exposé au sucrose. Nos résultats indiquent que le sucrose augmente l'activité spontanée des neurones DA de la VTA. En outre, si un choc électrique provoque une inhibition presque complète de l'activité de VTA neurones DA chez les rats témoins, le sucrose perturbe la signalisation d'un stimulus aversif, indépendamment de l’état calorique du rat. / Learning mechanisms associated with active responding for nicotine enhanced the excitability of the ILCx-BNST pathway. The objective of this project was to better understand the involvement of the ILCx-BNST pathway in nicotine self-administration. Since the endocannabinoid system controls nicotine reinforcement and nicotine-induced synaptic modifications, we examined the role of CB1 receptors in the BNST. We showed that acquisition of nicotine IVSA was associated with a persistent facilitation of LTP induction at ILCx-BNST synapses. Behaviorally, electrical stimulation temporarily increased excessive responding to nicotine when nicotine was not available. Moreover, using intra-BNST pharmacology, we revealed that stimulation of BNST CB1 receptors enhanced sensitivity to nicotine-paired cue. In contrast, after a prolonged history of nicotine intake, it blocked drug-seeking in a reinstatement model of relapse. Drug addiction is partly due to the inability to stop using despite negative consequences. The hypothesis that palatable food induces similar uncontrolled consumption is becoming more widespread. As drug addiction is known to increases activity of VTA DA neurons, we aimed to examine whether exposure to sucrose would induce similar neuronal modifications and impair the capacity to respond to an aversive stimulus. We found that sucrose enhanced spontaneous activity of DA VTA neurons. In addition, while a footshock caused a nearly complete inhibition of activity of VTA DA neurons in control rats, sucrose disrupted signaling of an aversive stimulus. These modifications were independent from the caloric state of the rats.

No description available.