L’échoendoscopie thérapeutique occupe une place croissante et incontournable de l’activité médico-chirurgicale en pathologie digestive depuis le développement des sondes sectorielles. Les domaines d’application de cette technique interventionnelle mini-invasive sont de plus en plus nombreux, d’une part en pathologie biliopancréatique et entérale permettant la réalisation d’anastomoses évitant un recours à la chirurgie traditionnelle, et d’autre part en cancérologie digestive car elle permet de délivrer un agent thérapeutique, une source de rayonnement ou des cellules liées au système immunitaire dans une lésion ciblée. L’abord vasculaire est une voie récente et prometteuse de l’échoendoscopie interventionnelle offrant des perspectives thérapeutiques en hépatologie notamment dans le domaine de l’hypertension portale. Ce travail se décompose en trois parties décrivant successivement l’état de l'art des applications de l’échoendoscopie interventionnelle, puis deux travaux originaux expérimentaux : dans un premier temps, le transfert de la technique d’anastomose biliodigestive (réalisée régulièrement dans notre centre) à l’abord vasculaire portosystémique sur animal sain, puis dans un deuxième temps la validité de la technique sur modèle animal de fibrose hépatique. La première série d’expérimentations a permis de mettre au point la technique de création d’un shunt intrahépatique portosystémique par échoendoscopie chez 23 cochons sains, en collaboration avec l’équipe de radiologie vasculaire. Ces procédures ont été réalisées dans une salle de cathétérisme vasculaire expérimentale (laboratoire Caviti) dans le cadre du laboratoire d’accueil ISIT (Image Science for Interventional Techniques, Pr. L. Boyer, Pr. J.-Y. Boire, UMR CNRS/UDA 6284). Les résultats ont été concluants puisque le shunt est apparu faisable dans 91% des cas, fonctionnel dans 81% des cas avec une morbidité de 14,2%. La deuxième série d’expérimentations a permis de valider cette technique d’échoendoscopie chez un modèle porcin de fibrose hépatique par embolisation radiologique, en collaboration avec l’Institut National de Recherche Agroalimentaire de Theix pour la stabulation des animaux. Ce travail multidisciplinaire a permis une collaboration étroite entre endoscopistes, radiologues, chirurgiens viscéraux et anatomopathologistes, s’inscrivant dans une démarche de recherche transversale. Les résultats sont encourageants puisqu’un shunt intrahépatique porto-systémique par échoendoscopie s’est révélé techniquement faisable et fonctionnel sur modèle de fibrose hépatique avec une survie à 7 jours des animaux dans deux tiers des cas. Avant d’envisager une étude princeps chez l’homme, des études complémentaires sont néanmoins nécessaires sur des modèles porcins présentant une fibrose hépatique associée à une hypertension portale en augmentant la durée de stabulation, en homogénéisant la procédure de squelettisation de l’artère hépatique et en adaptant la dose de solution injectée. Cette technique pourrait constituer à terme une alternative en cas d’échec de la technique standard pour complications de l’hypertension portale (shunt intrahépatique portosystémique par voie transjugulaire) chez des patients alors en situation d’impasse thérapeutique. / Therapeutic endoscopic ultrasonography is a growing and essential part of the medical and surgical activity in digestive pathology since the development of sectoral probes. The fields of application of this minimally invasive interventional technique are more and more numerous, on the one hand in biliopancreatic and enteral pathology, allowing the realization of anastomoses without traditional surgery, and on the other hand in digestive oncology, because it makes it possible to deliver a therapeutic agent, a source of radiation or cells linked to the immune system in a targeted lesion. The vascular approach is a recent and promising way of interventional endoscopic ultrasound offering therapeutic perspectives in hepatology, especially in the field of portal hypertension.This work is divided into three parts successively describing the state of the art of the applications of interventional ultrasonoscopy, then two original experimental works: initially, the transfer of the technique of biliodigestive anastomosis (performed regularly in our center ) at the portosystemic vascular approach on healthy animal, then in a second time the validity of the animal model technique of liver fibrosis.The first series of experiments led to the development of the technique for the creation of an intrahepatic shunt portosystemic by echoendoscopy in 23 healthy pigs, in collaboration with the vascular radiology team. These procedures were performed in an experimental vascular catheterization room (Caviti laboratory) as part of the ISIT host laboratory (Image Science for Interventional Techniques, Prof. L. Boyer, Pr. J.-Y.Boire, UMR CNRS / UDA 6284). The results were conclusive since the shunt appeared feasible in 91% of cases, functional in 81% of cases with a morbidity of 14.2%. The second series of experiments validated this endoscopic ultrasound technique in a porcine model of liver fibrosis by X-ray embolization, in collaboration with Theix National Institute for Food Research for Animal Stabling. This multidisciplinary work has allowed close collaboration between endoscopists, radiologists, visceral surgeons and anatomopathologists, as part of a transversal research approach. The results are encouraging since a porto-systemic intrahepatic shunt by endoscopic ultrasonography proved to be technically feasible and functional on a hepatic fibrosis model with a 7-day survival of the animals in two-thirds of the cases. Before considering a primary study in humans, additional studies are nevertheless necessary on porcine models presenting hepatic fibrosis associated with portal hypertension by increasing the duration of stabulation, by homogenizing the procedure of skeletonization of the hepatic artery and by adjusting the dose of injected solution. This technique could eventually be an alternative in case of failure of the standard technique for complications of portal hypertension (intrahepatic portosystemic shunt transjugular) in patients then in a situation of therapeutic impasse.

Each year liver cancer kills more than half a million people, making it the third leading cause of cancer-related death worldwide. Annual incidence continues to rise steadily, both domestically and globally, increasing the burden of this disease. Advancements in the ability to obtain detailed molecular profiles of tumors have led to the successful development of targeted therapies for a number of different cancers. Unfortunately, however, the molecular pathogenesis of liver cancer is poorly understood relative to many other types of malignancies. Thus, the identification of factors contributing to the development and progression of liver tumors is a major goal of current research. In pursuit of this goal, I have utilized the Sleeping Beauty (SB) transposon system as a tool for forward genetic mutagenesis screening in mice. The SB system recapitulates the kinetics of spontaneous tumor development in humans by providing a stepwise accumulation of mutations. Micro-evolutionary processes within a developing tumor lead to the selective expansion of cells harboring mutations that confer some kind of selective advantage. By identifying the most prevalent mutation events within a specific tumor type across a large number of independent samples, a list of genes implicated as being involved in tumorigenesis can be generated. Using this approach, the Dlk1-Dio3 imprinted domain was identified as a site of frequent mutation in SB-induced hepatocellular carcinomas (HCCs). I discovered that the mechanistic basis for recurrent selection of transposon insertion within this domain in liver tumors involved activated expression of Retrotransposon-like 1 (Rtl1). I also found that RTL1 activation is a common event in human HCC, suggesting that it could potentially be beneficial as a therapeutic target in a subset of patients. Etiological factors related to liver cancer development are varied, but are linked by the fact that each provides a chronic liver injury stimulus that promotes the development of hepatic fibrosis. In fact, ˜ 90% of human HCC occurs in this context, and yet the majority of mouse liver cancer models fail to account for this important environmental component of the disease. I have conducted a screen for genetic drivers of liver cancer in the presence or absence of hepatic fibrosis. Comparison of mutation profiles between fibrotic and non-fibrotic tumors revealed largely non-overlapping sets of candidate genes, indicative of a differential selective pressure for mutations depending on the fibrotic context of the liver. Driver mutations identified preferentially in the presence of liver fibrosis have a high likelihood of relevance to human disease, given the similarities in environmental context and kinetics of mutation acquisition. Consistent with this idea, multiple genes with well-established roles in human HCC were found to be preferentially mutated in SB-induced tumors developed in a fibrotic liver. Before a candidate cancer gene identified in an animal model system can have an impact on human disease, its proposed role in tumorigenesis must be validated. Existing techniques for validation of putative liver cancer genes suffer from significant limitations including high cost, low throughput, and a level of complexity that prohibits widespread utilization. I have contributed to the generation of a novel tool for in vivo validation of candidate genes that is not subject to these limitations. By combining elements of recombinant adenoviral vectors and the piggyBac transposition system, we have generated a highly flexible gene delivery system with significant advantages over existing techniques. The Ad-PB system has broad accessibility and applicability, making it a valuable tool for advancing efforts to improve cancer therapies.

Les infections humaines par Schistosoma japonicum et Schistosoma mansoni provoquent des pathologies hépatospléniques conduisant à la fibrose hépatique sévère chez 5 à 30% des sujets infectés vivant en zone endémique. Plusieurs études ont montré que le développement de cette fibrose était régulé par des cytokines mais aussi par des chimiokines. Les chimiokines sont des cytokines chimioattractantes produites par une variété des cellules immunes et non immunes, et qui ont été impliqués dans la régulation de l'inflammation granulomateuse et la fibrose pulmonaire et hépatique chez la souris et chez l'homme. Nous avons donc étudié la modulation des chimiokines et récepteurs dans le foie et la rate des patients hépatospléniques exposés à l'infection par S.japonicum. Notre étude démontre que les transcrits de chimiokines de type CXC et CC ainsi que des récepteurs sont augmentés dans le foie des patients hépatospléniques, lesquels ne sont pas significativement augmentés dans la rate au cours de l'infection. Cette augmentation des transcrits de chimiokines n'est pas restreinte aux chimiokines inflammatoires, une augmentation des transcrits des chimiokines homéostatiques CCL19 et CCL21 est aussi observée dans le foie des patients hépatospléniques. Nous avons également observé une corrélation des niveaux d'expression des ligands CXCR3 entre eux, dans le foie des sujets hépatospléniques. Ces observations suggèrent que les chimiokines régulent l'inflammation hépatique induite par les œufs de schistosomes et jouent probablement un rôle dans la fibrose hépatique. / Human infections with Schistosoma japonicum and Schistosoma mansoni causes hepatosplenic diseases leading to severe hepatic fibrosis in 5 to 30% of infected subjects living in endemic areas. Several studies demonstrated that the development of this fibrosis was regulated by cytokines but also by chemokines. Chemokines are the chemoattractant cytokines produced by a variety of immune and non-immune cells, and have been involved in the regulation of inflammation and granulomatous pulmonary and hepatic fibrosis in mice and humans. We therefore studied the modulation of chemokines and receptors in the liver and spleen of hepatosplenic patients exposed to infection with S.Japonicum. Our study demonstrates that the transcripts of CXC and CC chemokines and their receptors are increased in the liver of hepatosplenic patients, which were not significantly increased in the spleen during infection. This increase of transcripts of chemokines is not restricted to inflammatory chemokines, an increase of transcripts of homeostatic chemokines CCL19 and CCL21 is also observed in the liver of hepatosplenic patients. Moreover, the proportion of CD3+ lymphocytes but not CD14+ monocytes/macrophages is increased in the liver. We also observed a correlation of expression levels of CXCR3 ligands between them, in the liver of hepatosplenic subjects. These observations suggest that chemokines regulate hepatic inflammation induced by schistosoma eggs and probably play a role in liver fibrosis ensuing.

INTRODUÇÃO: A infecção pelo vírus da hepatite C é a principal causa de doença hepática crônica que progride para cirrose e carcinoma hepatocelular. Diversos fatores relacionados ao vírus e ao hospedeiro determinam a progressão para formas mais graves de fibrose hepática. A produção de espécies reativas de oxigênio (EROS) promovendo o estresse oxidativo contribui significativamente na fibrogênese hepática e pode ser gerada de múltiplas fontes, incluindo a cadeia respiratória mitocondrial, o citocromo p4502E1, peroxissomos e as NADPH oxidases (NOXs) no fígado. O sistema da NADPH (nicotinamide adenine dinucleotide phospate) oxidase tem uma participação muito importante na geração de EROS induzidas pelo vírus da hepatite C (VHC). Por isso, no presente estudo, investigamos dois polimorfismos de um único nucleotídeo (SNPs) na região reguladora dos genes codificadores da subunidade catalisadora da NADPH oxidase 4 (NOX4) e sua subunidade regulatória p22phox (CYBA) e a associação deles com variáveis metabólicas e histológicas em pacientes com VHC. MÉTODOS: Cento e setenta e oito pacientes portadores do VHC e virgens de tratamento (49,3% sexo masculino; 65% VHC genótipo 1) foram analisados. Todos os pacientes tinham VHC RNA positivo e foram genotipados para os SNPs rs3017887 na NOX4 e -675 T -> A na CYBA usando-se primer e probes específicos. RESULTADOS: Nenhuma associação foi vista entre as frequências genotípicas dos SNPs da NOX4 e CYBA com marcadores de inflamação ou grau de fibrose hepática na população total estudada. A presença dos genótipos CA + AA do SNP da NOX4 SNP teve associação com menor concentração sérica da alanino aminotransferase (ALT) na população masculina (CA + AA = 72,23 ± 6,34 U/L versus CC = 100,22 ± 9,85; média ± SEM; P = 0,05). O genótipo TT do SNP da CYBA teve associação com menor concentração sérica da ALT na população masculina (TT = 84,01 ± 6,77 U/L versus TA + AA = 109,67 ± 18,37 U/L; média ± SEM; P = 0,047). Por outro lado, o alelo menor do SNP da NOX4 foi inversamente associado com a frequência de síndrome metabólica (SM) na população masculina (odds ratio (OR): 0,15; 95% intervalo de confiança (IC): 0,03 - 0,79; P = 0,025). CONCLUSÕES: Os resultados sugerem que os SNPs da NOX4 e CYBA avaliados no estudo não são marcadores genéticos diretos de fibrose hepática em pacientes portadores do VHC, entretanto o SNP rs3017887 da NOX4 poderia influir indiretamente na susceptibilidade da fibrose hepática devido a associação inversa com SM nos pacientes do sexo masculino. / BACKGROUND: The hepatitis C virus infection is the leading cause of chronic liver disease that progresses into cirrhosis and hepatocellular carcinoma. Several factors related to the virus and the host determine the progression to more severe forms of liver fibrosis. The production of reactive oxygen species (ROS) promoting oxidative stress contribute significantly in liver fibrogenesis and can be generated from multiple sources, including mitochondrial respiratory chain, cytochrome p4502E1, peroxisomes and NADPH oxidases (NOXS) in the liver. Given the important contribution of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system to the generation of reactive oxygen species induced by hepatitis C virus (HCV), we investigated in the present study, two single nucleotide polymorphisms (SNPs) in the putative regulatory region of the genes encoding NADPH oxidase 4 catalytic subunit (NOX4) and its regulatory subunit p22phox (CYBA) and their relation with metabolic and histological variables in patients with HCV. METHODS: One hundred seventy eight naïve HCV patients (49.3% male; 65% HCV genotype 1) with positive HCV RNA were genotyped using specific primers and fluorescent-labeled probes for SNPs rs3017887 in NOX4 and -675 T -> A in CYBA. RESULTS: No association was found between the genotype frequencies of NOX4 and CYBA SNPs and inflammation scores or fibrosis stages in the overall population. The presence of the CA + AA genotypes of the NOX4 SNP was nominally associated with a lower alaninoamine transferase (ALT) concentration in the male population (CA + AA = 72.23 ± 6.34U/L versus CC = 100.22 ± 9.85; mean ± SEM; P = 0.05). The TT genotype of the CYBA SNP was also nominally associated with a lower ALT concentration in the male population (TT = 84.01 ± 6.77U/L versus TA + AA = 109.67 ± 18.37U/L; mean ± SEM; P = 0.047). The minor A-allele of the NOX4 SNP was inversely associated with the frequency of metabolic syndrome (MS) in the male population (odds ratio (OR): 0.15; 95% confidence interval (CI): 0.03 to 0.79; P = 0.025). CONCLUSIONS: The results suggest that the evaluated NOX4 and CYBA SNPs are not direct genetic determinants of fibrosis in HCV patients, but nevertheless NOX4 rs3017887 SNP could indirectly influence fibrosis susceptibility due to its inverse association with MS in male patients

Introdução: A Doença Hepática Gordurosa Não Alcoólica (DHGNA) tem sido considerada atualmente a forma mais comum de doença hepática no mundo ocidental, relacionada principalmente ao aumento da prevalência da obesidade.A DHGNA abrange um largo espectro de doença, desde casos de esteatose simples (EH) até esteato-hepatite não alcoólica (EHNA) e fibrose, podendo evoluir para cirrose e carcinoma hepatocelular (CHC). Embora se conheçam os fatores predisponentes para o desenvolvimento de EHNA, sua patogênese, assim como tratamento eficaz, permanecem pouco conhecidos.Os lípides, principalmente gorduras neutras, fosfolipídios e colesterol, são componentes fundamentais das células, assim como as proteínas e os hidratos de carbono. Embora aumentos marcantes de proteínas e hidratos de carbono não produzam quaisquer alterações macroscópicas no fígado, um acúmulo de gordura é prontamente reconhecido pela coloração amarelada e pelo aumento de volume do órgão. Várias dietas tem sido usadas em animais de laboratórios, principalmente camundongos e ratos no sentido de induzir esteatose, esteatohepatite e fibrose hepática, embora nenhuma delas consiga reproduzir na totalidade os componentes essenciais da doença humana. Não encontramos em nenhum trabalho da literatura a utilização da dieta deficiente em colina e hiperlipídica (DCH), por nós utilizada. Objetivo: O objetivo deste estudo foi avaliar o efeito de uma dieta deficiente em colina e hiperlipídica (DCH) para desenvolver esteatose hepática, esteatohepatite e fibrose hepática no rato. Métodos: A doença hepática foi induzida em ratos Sprague-Dawley machos pesando de 300 a 350 gramas, hospedados em gaiolas padrão e recebendo água à vontade. Foi usado dieta deficiente em colina e hiperlipídica (DCH). Os animais foram distribuídos por meio de tabela sequencial randomizada em dois grupos. No grupo 1 dez ratos receberam a dieta por 4 meses e no grupo 2 dez ratos receberam a dieta durante 8 meses. Após o tempo estipulado das dietas os animais foram anestesiados e sacrificados. Os fígados dos animais foram retirados, pesados e enviados para estudo histopatológico de acordo com os critérios estabelecidos por Kleiner. Os animais foram pesados no início do experimento e por ocasião do sacrifício. Resultados: o peso dos animais do grupo 1 (DCH - 4 meses) no início do experimento variou de 305 a 350 gramas com média de 329,9 gramas e no fim do experimento de 529 a 615 gramas com média de 579,2 gramas. O percentual de ganho de peso dos animais variou de 60 a 86,93% com média de 75,72%. O peso dos animais do grupo 2 (DCH - 8 meses) no início do experimento variou de 320 a 353 gramas com média de 339,4 gramas e no fim do experimento variou de 661,5 a 783 gramas com média de 705,6 gramas. O percentual do ganho de peso dos animais variou de 95,58 a 123,71% com média de 107,78%. O peso do fígado dos animais do grupo 1 no fim do experimento variou de 24,5 a 29,5 gramas. O percentual do peso do fígado em relação ao peso dos animais do grupo 1 variou de 4,16 a 5,54% com média de 4,75%. O peso do fígado dos animais do grupo 2 no fim do experimento variou de 31 gramas a 39 gramas com média de 33,8 gramas. O percentual do peso do fígado em relação ao peso dos animais do grupo 2 variou de 4,63% a 5,07%, com média de 4,78%. A análise histopatológica dos animais do grupo 1 demonstrou intensa balonização e esteatose microgoticular com inflamação lobular; o estadiamento de fibrose foi discreto nestes animais. O estudo histopatológico dos animais do grupo 2 revelou intensa esteatose microgoticular e balonização com inflamação lobular; alguns animais apresentaram esteatose macrogoticular. Os animais deste grupo 2 apresentaram fibrose com grande variação individual. Os animais de ambos os grupos experimentais desenvolveram esteatohepatite, pois apresentaram o índice de atividade da doença hepática gordurosa não alcoólica (NAS)>=5. A análise comparativa demonstrou não haver diferença estatística no valor do NAS entre os dois grupos experimentais. Em relação ao estadiamento da fibrose na esteatohepatite não alcoólica, os animais do grupo 2 apresentaram uma tendência de escores mais elevados do que os animais do grupo 1. No entanto não houve diferença estatística entre os grupos devido a grande variação individual (p=0,2755). Conclusões: A dieta DCH administrada durante 4 e 8 meses induziu nos ratos aumento considerável de peso corpóreo e do peso do fígado. Os animais do grupo 1 apresentaram intensa balonização, esteatose microgoticular e inflamação lobular com discreta fibrose hepática. Os animais do grupo 2 apresentaram intensa balonização, esteatose macro e microgoticular, inflamação lobular e maior grau de fibrose hepática, bem estabelecida com formação de colágeno e expansão fibrosa nos espaços vasculares. A dieta deficiente em colina e hiperlipídica (DCH) induziu no rato esteatose hepática e esteatohepatite com fibrose, servindo de modelo experimental para proporcionar melhor entendimento para procedimentos terapêuticos futuros desta importante patologia do fígado. / Introduction: Nonalcoholic Fatty Liver Disease (NAFLD) has currently been regarded as the most common form of liver disease in the western world, mainly related to the increased prevalence of obesity. NAFLD covers a broad spectrum of diseases, since cases of simple steatosis (HS) to steatohepatitis (EHNA) and fibrosis, and may evolve to cirrhosis and hepatocellular carcinoma (CHC). Although the predisposing factors for the development of EHNA are well established, there is little knowledge on its pathogenesis as well as the effective treatment options. Lipids, especially phospholipids, neutral fats and cholesterol, are fundamental cell components, as well as proteins and carbohydrates. Although striking increases of proteins and carbohydrates do not produce liver macroscopic changes, fat build up can be rapidly recognized by the yellow coloring and increased organ volume. Many diets have been used in laboratory animals, mainly rats although none of them can fully reproduce the fundamental components of the human disease. We could not find in the literature any study on the use of choline-deficient and hiperlipidic diet (CHD), used in the present study. Goal: The objective of this study was to evaluate the effect of a cholinedeficient and hiperlipidic diet (CHD) on the development of steatosis, steatohepatitis and hepatic fibrosis in rats. Methods: The liver disease was induced in male Sprague-Dawley rats, weighing from 300 to 350 grams, hosted in standard cages and receiving water ad libitum and fed with a choline-deficient and hiperlipidic diet (CHD). The experimental animals were distributed by means of a random sequential table in two groups. In Group 1 ten rats received the diet for four months and in Group 2 ten rats received the same diet for eight months. After these predetermined feeding time periods the animals were anesthetized and sacrificed. The animal livers were then removed, weighed and sent to histopathological study according to the criteria established by Kleiner. All the animals were weighed at the beginning of the experiment and by the time of the sacrifice. Results: The weight of Group 1 animals (4 months CHD) at the beginning of the experiment varied from 305 to 350 grams with an average of 329.9 grams and at the end of the experiment from 529 to 615 grams averaging 579.2 grams. The percentage of weight gain in animals of this group ranged from 60% to 86.93% with an average of 75.72%. The weight of Group 2 animals (8 months CHD) at the start of the experiment varied from 320 to 353 grams with an average of 339.4 grams and at the end of the experiment from the 661.5 to 783 g with an average of 705.6 grams. The percentage of weight gain in animals of this group varied from 95.58% to 123.71%, averaging 107.78%. The liver weight of Group 1 animals at the end of the experiment varied from 24.5 to 29.5 grams. The percentage of liver weight in relation to the animals\' weight, in Group 1, ranged from 4.16% to 5.54%, with an average of 4.75%. The liver weight of Group 2 animals at the end of the experiment varied from 31gramas to 39 grams, with an average of 33.8 gram. The percentage of liver weight in relation to the animals\' weight, in Group 2, ranged from 4.63% to 5.07%, with an average of 4.78%. Liver histopathological analysis in Group 1 animals showed marked ballooning degeneration and microgoticular steatosis with lobular inflammation; fibrosis staging was discreet in these animals. Liver histopathological study in animals of Group 2 showed an intense microgoticular steatosis and ballooning with lobular inflammation; some animals of this group presented macrogoticular steatosis. The amount of hepatic fibrosis in animals of this group was extremely variable. Animals of both experimental groups developed steatohepatitis, as they presented the activity index of nonalcoholic fatty liver disease (NAS) >= 5. Statistical analysis did not show a significant difference between the NAS values of the two experimental groups. Fibrosis staging analysis in non-alcoholic steatohepatitis showed a trend toward higher scores in animals of Group 2 as compared to Group 1 animals. However there was no statistical difference between the groups due to a large individual variation (p = 0.2755). Conclusions: CHD diet administered for four and eight months induced considerable increases in the rats\' body weight and liver weight. Animals in Group 1 showed intense liver ballooning, steatosis and lobular inflammation with discrete microgoticular fibrosis. Animals in Group 2 presented intense ballooning, steatosis macro and microgoticular, lobular inflammation and a higher degree of well-established hepatic fibrosis, with collagen formation with fibrotic expansion in vascular spaces. Choline-deficient and hiperlipidic diet (CHD) in the rat induced hepatic steatosis and steatohepatitis with fibrosis, representing an experimental model, which can provide a better knowledge for future therapeutic procedures of this important liver pathology.

As hepatites crônicas por vírus são as mais frequentes, destacando-se os vírus das hepatites B (VHB) e C (VHC). O estudo anatomopatológico da biópsia hepática é considerado o padrão ouro para avaliar com precisão a distorção arquitetural e o grau de fibrose do parênquima do fígado, importantes fatores prognósticos para os pacientes portadores de hepatites crônicas virais. Na avaliação histopatológica atual, em adição aos relatos subjetivos das alterações histológicas, escores semiquantitativos que correlacionam achados morfológicos com graus numéricos são usados, tais como os reconhecidos escores de Ishak e METAVIR. Entretanto, em todos estes sistemas há a desvantagem da subjetividade do examinador e da incorporação de alterações categóricas, sem referências às mudanças quantitativas do colágeno hepático. Técnicas de análise de imagens digitais (AID) que fornecem quantificação objetiva dos graus de fibrose em amostras histológicas têm sido desenvolvidas. Todavia, o alto custo e dificuldade ao acesso das tecnologias descritas restringem seu uso a poucos centros especializados. Este estudo visa o desenvolvimento de uma técnica de custo acessível para a análise de imagens digitais da fibrose hepática em hepatites crônicas virais. Foram estudadas 304 biópsias de pacientes com hepatite crônica por vírus B e C, obtidas através de agulhas Menghini. Todas as amostras tinham pelo menos 15 mm de comprimento ou cinco espaços-porta completos e foram coradas pelo método Tricrômico de Masson. O estadiamento foi feito por um único hepatopatologista experiente, sem o conhecimento dos dados clínicos dos pacientes. Os escores de Ishak e METAVIR foram aplicados. As imagens microscópicas foram digitalizadas. Os índices de fibrose foram determinados de forma automatizada, em técnica desenvolvida no programa Adobe Photoshop. Para o escore de Ishak, observamos os seguintes índices de Fibrose (IF) médios: 0,8% 0,0 (estágio 0), 2.4% 0,6 (estágio 1), 4,7% 1,6 (estágio 2), 7,4% 1,4 (estágio 3), 14,9% 3,7 (estágio 4), 23,4% 2,9 (estágio 5) e 34,5% 1,5 (estágio 6). Para a classificação METAVIR: 0,8% 0,1 (estágio F0), 3,8% 1,8 (estágio F1), 7,4% 1,4 (estágio F2), 20,4% 5,2 (estágio F3) e 34,5% 1,5 (estágio F4). Observamos uma excelente correlação entre os índices de fibrose da AID e os escores de Ishak (r=0,94; p<0,001) e METAVIR (r=0,92; p<0,001). Em relação à indicação de tratamento antiviral, foi observado IF médio de 16,4%. Em relação ao diagnóstico de cirrose, foi observado IF médio de 26,9%, para o escore de Ishak, e 34,5% para a classificação METAVIR. A reprodutibilidade intra-observador foi excelente. Este novo método de análise de imagens digitais para a quantificação de fibrose hepática tem custo acessível e foi desenvolvido com tecnologia que está disponível em todo o mundo, permitindo identificar com precisão todos os estágios de fibrose, com excelente reprodutibilidade intra-observador. / The hepatitis caused by viruses are the most frequent, principally the virus B (HBV) and C (HCV) hepatitis. The anatomopathologic study of the liver biopsy is considered the gold standard for the evaluation of architectural distortion and degree o fibrosis of the livers parenchyma, important prognostic factors for the patients with chronic viral hepatitis. In the actual histopathological evaluation, in addition to subjective reports of histological alterations, semiquantitative scores that correlate morphological findings with numeric degrees are used, such as the renowned Ishak and METAVIR scores. However, in all of these systems there is the disadvantage of the subjectiveness of the examinator and the incorporation of categorical description of architectural changes without reference to quantitative changes in liver collagen. Digital Image Analysis techniques (DIA) that provide objective quantification of the degrees of liver fibrosis in histological samples have been developed. But the high cost and worldwide unavailability of the technologies described restrained their use to a few specialized centers. This study aims at developing an affordable technique for livers fibrosis DIA in chronic viral hepatitis. Three hundred and four core needle biopsies obtained by Menghini needles from patients with virus B and virus C hepatitis were studied. All samples had at least 15 mm in length or five complete portal tracts and were stained with the Massons Trichrome Method. The staging by Ishaks and METAVIRs scores was done by a single experienced hepatopathologist, without the knowledge patients clinical data. The microscopic images were digitalized. The fibrosis indexes were calculated in an automated way by a new technique developed in the Adobe Photoshop software. For the Ishak score the following median Fibrosis Indexes (FI) were observed: 0,8% 0,0 (stage 0), 2.4% 0,6 (stage 1), 4,7% 1,6 (stage 2), 7,4% 1.4 (stage 3), 14,9% 3.7 (stage 4), 23,4% 2.9 (stage 5) e 34,5% 1,5 (stage 6). For the METAVIR classification: 0,8% 0,1 (stage F0), 3,8% 1.8 (stage F1), 7,4% 1.4 (stage F2), 20,4% 5,2 (stage F3) e 34,5% 1,5 (stage F4). We found an excellent correlation between the DIA fibrosis indexes and the Ishaks (r=0.94; p<0.001) and METAVIR (r=0.92; p<0.001) stages. In relation to the indication for antiviral treatment, the mean FI observed was 16.4% for both classifications. In relation to cirrhosiss diagnosis, the mean FI observed was 26.9% for Ishaks score, and 34.5% for METAVIRs classification. There was excellent intraobserver reproducibility. This new method of digital image analysis for liver fibrosis quantification is affordable and was developed using technology that is available worldwide, allowing the precise identification of all the stages of fibrosis in the group of patients studied, with excellent intraobserver reproducibility.

Objectifs : Les objectifs principaux de cette thèse sont les suivants : 1) analyse de l’évolution du profil épidémiologique des patients coinfectés VIH-VHC initiant le traitement de l’hépatite C; 2) l’évaluation de l’impact des comportements de santé et des styles de vie sur l’évolution clinique de la maladie Résultats : J’ai pu mettre en évidence que le profil des patients coinfectés VIH-VHC initiant un traitement de l’hépatite C a changé en France avec l’évolution des traitements.Mes travaux ont permis de montrer que, chez les patients coinfectés VIH-VHC, une consommation élevée de café (3 tasses par jour et plus) diminue le risque de fibrose hépatique avancée. Cet effet bénéfique du café est également observé chez les patients coinfectés VIH-VHC avec une consommation élevée d’alcool. De plus, mes travaux ont mis en évidence une relation dose-dépendante entre la fréquence de consommation de cacao et la réduction du risque de fibrose hépatique avancée chez les patients coinfectés VIH-VHC. Par ailleurs, mes analyses n’ont pas mis en évidence un effet significatif de la consommation de café sur le risque de fibrose hépatique avancée chez les femmes coinfectées VIH-VHC. Enfin l’un des résultats marquant de la relation entre VHC et risque d’obésité qui est connue est que la guérison augmente davantage ce risque sur le long terme. Conclusion : Des interventions pour modifier certains styles de vie et comportements ont le potentiel de diminuer le risque de survenue ou d’aggravation de comorbidités, en particulier après la guérison VHC, un événement désormais atteignable pour tous les patients coinfectés. / Objectives: The main objectives of this thesis are: 1) analysis of the evolution of the epidemiological profile of co-infected HIV-HCV patients initiating the treatment of hepatitis C; 2) assessment of the impact of health behaviors and lifestyles on the clinical course of the diseaseResults: I was able to highlight that the profile of co-infected HIV-HCV patients initiating treatment for hepatitis C has changed in France with the evolution of treatments.My work has shown that, in HIV-HCV coinfected patients, high coffee consumption (3 cups per day or more) decreases the risk of advanced liver fibrosis. This beneficial effect of coffee is also observed in co-infected HIV-HCV patients with high alcohol consumption. In addition, my work has shown a dose-dependent relationship between the frequency of cocoa consumption and the reduced risk of advanced liver fibrosis in coinfected HIV-HCV patients. Furthermore, my analyzes did not reveal a significant effect of coffee consumption on the risk of advanced liver fibrosis in coinfected HIV-HCV women. Finally, one of the striking results of the relationship between HCV and known risk of obesity is that healing increases this risk in the long term.Conclusion: Interventions to modify certain lifestyles and behaviors have the potential to reduce the risk of developing or worsening comorbidities, particularly after HCV healing, an event now achievable for all co-infected patients.

Orientador: Roberto Carlos Burini / Resumo: Fetuina-A é uma glicoproteína multifuncional, sintetizada pelo fígado como proteína de fase aguda. Atua na inibição da cascata da insulina, e estimula a síntese de citocinas pró-inflamatórias. Assim, sugere-se que a fetuina-A esteja envolvida na patogênese da doença gordurosa hepática não-alcoólica (DGHNA), constituindo-se em um dos seus indicadores. O presente estudo tem como objetivo investigar as concentrações de fetuina-A na DGHNA e sua associação com distúrbios metabólicos, bem como, com o risco de fibrose hepática, e doença cardiovascular (DCV), mediante marcadores bioquímicos. Para tanto, foi realizado estudo transversal com mulheres ingressantes em programa para mudança do estilo de vida. Foram avaliadas 148 mulheres com idade entre 35 a 78 anos, as quais foram submetidas às avaliações clínicas, sócio-demográfica, antropométrica, de consumo alimentar e análises bioquímicas. O nível de significância considerado foi p<0,05. Verificou-se DGHNA, pelo Índice de Gordura Hepática (IGH≥60), em 55,4% das mulheres. Fetuina-A sérica correlacionou-se positivamente com Índice de Massa Corporal, circunferência abdominal, IGH e proteína C-reativa ultra-sensível (PCR-us). A proporção de mulheres com resistência insulínica (RI) pelo modelo homeostático de resistência à insulina (HOMA-IR) foi maior dentre os valores maiores (Tercil 3) de fetuina-A, comparativamente, aos menores valores (Tercil 1). Resultado análogo foi encontrado para a PCR-us, mas não para proteína ligadora de lipopol... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Fetuin-A is a multifunctional glycoprotein, synthesized by the liver as a acute phase protein. It acts in insulin cascade inhibition, and stimulates pro-inflammatory cytokines. It is postulated that fetuin-A is involved in non-alcoholic fatty liver disease (NAFLD) pathogenesis, as one of its indicators. The present study aims to investigate fetuin-A concentration in NAFLD and its association with metabolic disturbers, as well as with hepatic fibrosis risk, and cardiovascular disease (CVD), through biochemical markers. For that, a cross-sectional study was carried out with women entering a lifestyle modification program. We evaluate 148 women, with age that range from 35 to 78 years old that were submitted to clinical, sociodemographic, anthropometric, food consumption and biochemical evaluation. The statistical significance considered was p<0,05. We verified that NAFLD, measured by Fatty Liver Index (FLI ≥60), was found in 55.4% of women. Serum fetuin-A was positively correlated with Body Mass Index, waist circumference, FLI and high-sensitivity C-reactive protein (hs-CRP). The proportion of women with insulin resistance (IR) by insulin resistance homeostatic model assessment (HOMA-IR), was higher among the higher values (Tercil 3) of fetuin-A, compared to the lowest values (Tercil 1). Analog results were found to hs-CRP, but not to lipopolysaccharide-binding protein (LBP), albuminemia and hepatic fibrosis. After adjustments, HOMA-IR and hs-CRP altered, constitute independent... (Complete abstract click electronic access below) / Mestre

As hepatites crônicas por vírus são as mais frequentes, destacando-se os vírus das hepatites B (VHB) e C (VHC). O estudo anatomopatológico da biópsia hepática é considerado o padrão ouro para avaliar com precisão a distorção arquitetural e o grau de fibrose do parênquima do fígado, importantes fatores prognósticos para os pacientes portadores de hepatites crônicas virais. Na avaliação histopatológica atual, em adição aos relatos subjetivos das alterações histológicas, escores semiquantitativos que correlacionam achados morfológicos com graus numéricos são usados, tais como os reconhecidos escores de Ishak e METAVIR. Entretanto, em todos estes sistemas há a desvantagem da subjetividade do examinador e da incorporação de alterações categóricas, sem referências às mudanças quantitativas do colágeno hepático. Técnicas de análise de imagens digitais (AID) que fornecem quantificação objetiva dos graus de fibrose em amostras histológicas têm sido desenvolvidas. Todavia, o alto custo e dificuldade ao acesso das tecnologias descritas restringem seu uso a poucos centros especializados. Este estudo visa o desenvolvimento de uma técnica de custo acessível para a análise de imagens digitais da fibrose hepática em hepatites crônicas virais. Foram estudadas 304 biópsias de pacientes com hepatite crônica por vírus B e C, obtidas através de agulhas Menghini. Todas as amostras tinham pelo menos 15 mm de comprimento ou cinco espaços-porta completos e foram coradas pelo método Tricrômico de Masson. O estadiamento foi feito por um único hepatopatologista experiente, sem o conhecimento dos dados clínicos dos pacientes. Os escores de Ishak e METAVIR foram aplicados. As imagens microscópicas foram digitalizadas. Os índices de fibrose foram determinados de forma automatizada, em técnica desenvolvida no programa Adobe Photoshop. Para o escore de Ishak, observamos os seguintes índices de Fibrose (IF) médios: 0,8% 0,0 (estágio 0), 2.4% 0,6 (estágio 1), 4,7% 1,6 (estágio 2), 7,4% 1,4 (estágio 3), 14,9% 3,7 (estágio 4), 23,4% 2,9 (estágio 5) e 34,5% 1,5 (estágio 6). Para a classificação METAVIR: 0,8% 0,1 (estágio F0), 3,8% 1,8 (estágio F1), 7,4% 1,4 (estágio F2), 20,4% 5,2 (estágio F3) e 34,5% 1,5 (estágio F4). Observamos uma excelente correlação entre os índices de fibrose da AID e os escores de Ishak (r=0,94; p<0,001) e METAVIR (r=0,92; p<0,001). Em relação à indicação de tratamento antiviral, foi observado IF médio de 16,4%. Em relação ao diagnóstico de cirrose, foi observado IF médio de 26,9%, para o escore de Ishak, e 34,5% para a classificação METAVIR. A reprodutibilidade intra-observador foi excelente. Este novo método de análise de imagens digitais para a quantificação de fibrose hepática tem custo acessível e foi desenvolvido com tecnologia que está disponível em todo o mundo, permitindo identificar com precisão todos os estágios de fibrose, com excelente reprodutibilidade intra-observador. / The hepatitis caused by viruses are the most frequent, principally the virus B (HBV) and C (HCV) hepatitis. The anatomopathologic study of the liver biopsy is considered the gold standard for the evaluation of architectural distortion and degree o fibrosis of the livers parenchyma, important prognostic factors for the patients with chronic viral hepatitis. In the actual histopathological evaluation, in addition to subjective reports of histological alterations, semiquantitative scores that correlate morphological findings with numeric degrees are used, such as the renowned Ishak and METAVIR scores. However, in all of these systems there is the disadvantage of the subjectiveness of the examinator and the incorporation of categorical description of architectural changes without reference to quantitative changes in liver collagen. Digital Image Analysis techniques (DIA) that provide objective quantification of the degrees of liver fibrosis in histological samples have been developed. But the high cost and worldwide unavailability of the technologies described restrained their use to a few specialized centers. This study aims at developing an affordable technique for livers fibrosis DIA in chronic viral hepatitis. Three hundred and four core needle biopsies obtained by Menghini needles from patients with virus B and virus C hepatitis were studied. All samples had at least 15 mm in length or five complete portal tracts and were stained with the Massons Trichrome Method. The staging by Ishaks and METAVIRs scores was done by a single experienced hepatopathologist, without the knowledge patients clinical data. The microscopic images were digitalized. The fibrosis indexes were calculated in an automated way by a new technique developed in the Adobe Photoshop software. For the Ishak score the following median Fibrosis Indexes (FI) were observed: 0,8% 0,0 (stage 0), 2.4% 0,6 (stage 1), 4,7% 1,6 (stage 2), 7,4% 1.4 (stage 3), 14,9% 3.7 (stage 4), 23,4% 2.9 (stage 5) e 34,5% 1,5 (stage 6). For the METAVIR classification: 0,8% 0,1 (stage F0), 3,8% 1.8 (stage F1), 7,4% 1.4 (stage F2), 20,4% 5,2 (stage F3) e 34,5% 1,5 (stage F4). We found an excellent correlation between the DIA fibrosis indexes and the Ishaks (r=0.94; p<0.001) and METAVIR (r=0.92; p<0.001) stages. In relation to the indication for antiviral treatment, the mean FI observed was 16.4% for both classifications. In relation to cirrhosiss diagnosis, the mean FI observed was 26.9% for Ishaks score, and 34.5% for METAVIRs classification. There was excellent intraobserver reproducibility. This new method of digital image analysis for liver fibrosis quantification is affordable and was developed using technology that is available worldwide, allowing the precise identification of all the stages of fibrosis in the group of patients studied, with excellent intraobserver reproducibility.

Introdução: A Doença Hepática Gordurosa Não Alcoólica (DHGNA) tem sido considerada atualmente a forma mais comum de doença hepática no mundo ocidental, relacionada principalmente ao aumento da prevalência da obesidade.A DHGNA abrange um largo espectro de doença, desde casos de esteatose simples (EH) até esteato-hepatite não alcoólica (EHNA) e fibrose, podendo evoluir para cirrose e carcinoma hepatocelular (CHC). Embora se conheçam os fatores predisponentes para o desenvolvimento de EHNA, sua patogênese, assim como tratamento eficaz, permanecem pouco conhecidos.Os lípides, principalmente gorduras neutras, fosfolipídios e colesterol, são componentes fundamentais das células, assim como as proteínas e os hidratos de carbono. Embora aumentos marcantes de proteínas e hidratos de carbono não produzam quaisquer alterações macroscópicas no fígado, um acúmulo de gordura é prontamente reconhecido pela coloração amarelada e pelo aumento de volume do órgão. Várias dietas tem sido usadas em animais de laboratórios, principalmente camundongos e ratos no sentido de induzir esteatose, esteatohepatite e fibrose hepática, embora nenhuma delas consiga reproduzir na totalidade os componentes essenciais da doença humana. Não encontramos em nenhum trabalho da literatura a utilização da dieta deficiente em colina e hiperlipídica (DCH), por nós utilizada. Objetivo: O objetivo deste estudo foi avaliar o efeito de uma dieta deficiente em colina e hiperlipídica (DCH) para desenvolver esteatose hepática, esteatohepatite e fibrose hepática no rato. Métodos: A doença hepática foi induzida em ratos Sprague-Dawley machos pesando de 300 a 350 gramas, hospedados em gaiolas padrão e recebendo água à vontade. Foi usado dieta deficiente em colina e hiperlipídica (DCH). Os animais foram distribuídos por meio de tabela sequencial randomizada em dois grupos. No grupo 1 dez ratos receberam a dieta por 4 meses e no grupo 2 dez ratos receberam a dieta durante 8 meses. Após o tempo estipulado das dietas os animais foram anestesiados e sacrificados. Os fígados dos animais foram retirados, pesados e enviados para estudo histopatológico de acordo com os critérios estabelecidos por Kleiner. Os animais foram pesados no início do experimento e por ocasião do sacrifício. Resultados: o peso dos animais do grupo 1 (DCH - 4 meses) no início do experimento variou de 305 a 350 gramas com média de 329,9 gramas e no fim do experimento de 529 a 615 gramas com média de 579,2 gramas. O percentual de ganho de peso dos animais variou de 60 a 86,93% com média de 75,72%. O peso dos animais do grupo 2 (DCH - 8 meses) no início do experimento variou de 320 a 353 gramas com média de 339,4 gramas e no fim do experimento variou de 661,5 a 783 gramas com média de 705,6 gramas. O percentual do ganho de peso dos animais variou de 95,58 a 123,71% com média de 107,78%. O peso do fígado dos animais do grupo 1 no fim do experimento variou de 24,5 a 29,5 gramas. O percentual do peso do fígado em relação ao peso dos animais do grupo 1 variou de 4,16 a 5,54% com média de 4,75%. O peso do fígado dos animais do grupo 2 no fim do experimento variou de 31 gramas a 39 gramas com média de 33,8 gramas. O percentual do peso do fígado em relação ao peso dos animais do grupo 2 variou de 4,63% a 5,07%, com média de 4,78%. A análise histopatológica dos animais do grupo 1 demonstrou intensa balonização e esteatose microgoticular com inflamação lobular; o estadiamento de fibrose foi discreto nestes animais. O estudo histopatológico dos animais do grupo 2 revelou intensa esteatose microgoticular e balonização com inflamação lobular; alguns animais apresentaram esteatose macrogoticular. Os animais deste grupo 2 apresentaram fibrose com grande variação individual. Os animais de ambos os grupos experimentais desenvolveram esteatohepatite, pois apresentaram o índice de atividade da doença hepática gordurosa não alcoólica (NAS)>=5. A análise comparativa demonstrou não haver diferença estatística no valor do NAS entre os dois grupos experimentais. Em relação ao estadiamento da fibrose na esteatohepatite não alcoólica, os animais do grupo 2 apresentaram uma tendência de escores mais elevados do que os animais do grupo 1. No entanto não houve diferença estatística entre os grupos devido a grande variação individual (p=0,2755). Conclusões: A dieta DCH administrada durante 4 e 8 meses induziu nos ratos aumento considerável de peso corpóreo e do peso do fígado. Os animais do grupo 1 apresentaram intensa balonização, esteatose microgoticular e inflamação lobular com discreta fibrose hepática. Os animais do grupo 2 apresentaram intensa balonização, esteatose macro e microgoticular, inflamação lobular e maior grau de fibrose hepática, bem estabelecida com formação de colágeno e expansão fibrosa nos espaços vasculares. A dieta deficiente em colina e hiperlipídica (DCH) induziu no rato esteatose hepática e esteatohepatite com fibrose, servindo de modelo experimental para proporcionar melhor entendimento para procedimentos terapêuticos futuros desta importante patologia do fígado. / Introduction: Nonalcoholic Fatty Liver Disease (NAFLD) has currently been regarded as the most common form of liver disease in the western world, mainly related to the increased prevalence of obesity. NAFLD covers a broad spectrum of diseases, since cases of simple steatosis (HS) to steatohepatitis (EHNA) and fibrosis, and may evolve to cirrhosis and hepatocellular carcinoma (CHC). Although the predisposing factors for the development of EHNA are well established, there is little knowledge on its pathogenesis as well as the effective treatment options. Lipids, especially phospholipids, neutral fats and cholesterol, are fundamental cell components, as well as proteins and carbohydrates. Although striking increases of proteins and carbohydrates do not produce liver macroscopic changes, fat build up can be rapidly recognized by the yellow coloring and increased organ volume. Many diets have been used in laboratory animals, mainly rats although none of them can fully reproduce the fundamental components of the human disease. We could not find in the literature any study on the use of choline-deficient and hiperlipidic diet (CHD), used in the present study. Goal: The objective of this study was to evaluate the effect of a cholinedeficient and hiperlipidic diet (CHD) on the development of steatosis, steatohepatitis and hepatic fibrosis in rats. Methods: The liver disease was induced in male Sprague-Dawley rats, weighing from 300 to 350 grams, hosted in standard cages and receiving water ad libitum and fed with a choline-deficient and hiperlipidic diet (CHD). The experimental animals were distributed by means of a random sequential table in two groups. In Group 1 ten rats received the diet for four months and in Group 2 ten rats received the same diet for eight months. After these predetermined feeding time periods the animals were anesthetized and sacrificed. The animal livers were then removed, weighed and sent to histopathological study according to the criteria established by Kleiner. All the animals were weighed at the beginning of the experiment and by the time of the sacrifice. Results: The weight of Group 1 animals (4 months CHD) at the beginning of the experiment varied from 305 to 350 grams with an average of 329.9 grams and at the end of the experiment from 529 to 615 grams averaging 579.2 grams. The percentage of weight gain in animals of this group ranged from 60% to 86.93% with an average of 75.72%. The weight of Group 2 animals (8 months CHD) at the start of the experiment varied from 320 to 353 grams with an average of 339.4 grams and at the end of the experiment from the 661.5 to 783 g with an average of 705.6 grams. The percentage of weight gain in animals of this group varied from 95.58% to 123.71%, averaging 107.78%. The liver weight of Group 1 animals at the end of the experiment varied from 24.5 to 29.5 grams. The percentage of liver weight in relation to the animals\' weight, in Group 1, ranged from 4.16% to 5.54%, with an average of 4.75%. The liver weight of Group 2 animals at the end of the experiment varied from 31gramas to 39 grams, with an average of 33.8 gram. The percentage of liver weight in relation to the animals\' weight, in Group 2, ranged from 4.63% to 5.07%, with an average of 4.78%. Liver histopathological analysis in Group 1 animals showed marked ballooning degeneration and microgoticular steatosis with lobular inflammation; fibrosis staging was discreet in these animals. Liver histopathological study in animals of Group 2 showed an intense microgoticular steatosis and ballooning with lobular inflammation; some animals of this group presented macrogoticular steatosis. The amount of hepatic fibrosis in animals of this group was extremely variable. Animals of both experimental groups developed steatohepatitis, as they presented the activity index of nonalcoholic fatty liver disease (NAS) >= 5. Statistical analysis did not show a significant difference between the NAS values of the two experimental groups. Fibrosis staging analysis in non-alcoholic steatohepatitis showed a trend toward higher scores in animals of Group 2 as compared to Group 1 animals. However there was no statistical difference between the groups due to a large individual variation (p = 0.2755). Conclusions: CHD diet administered for four and eight months induced considerable increases in the rats\' body weight and liver weight. Animals in Group 1 showed intense liver ballooning, steatosis and lobular inflammation with discrete microgoticular fibrosis. Animals in Group 2 presented intense ballooning, steatosis macro and microgoticular, lobular inflammation and a higher degree of well-established hepatic fibrosis, with collagen formation with fibrotic expansion in vascular spaces. Choline-deficient and hiperlipidic diet (CHD) in the rat induced hepatic steatosis and steatohepatitis with fibrosis, representing an experimental model, which can provide a better knowledge for future therapeutic procedures of this important liver pathology.