Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-14T14:16:56Z No. of bitstreams: 1 lilianaandradechebli.pdf: 4797149 bytes, checksum: 48711245cd6bc4dca1d8093d1e776787 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-29T12:12:52Z (GMT) No. of bitstreams: 1 lilianaandradechebli.pdf: 4797149 bytes, checksum: 48711245cd6bc4dca1d8093d1e776787 (MD5) / Made available in DSpace on 2017-06-29T12:12:52Z (GMT). No. of bitstreams: 1 lilianaandradechebli.pdf: 4797149 bytes, checksum: 48711245cd6bc4dca1d8093d1e776787 (MD5) Previous issue date: 2009-08-06 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Colite ulcerativa é uma condição inflamatória imuno-mediada da mucosa colônica, caracterizada por curso intermitente e recorrente. Corticosteróides permanecem como uma das terapias mais efetivas para induzir remissão em pacientes com colite ulcerativa moderada a severa. Todavia, corticosteróides não são usados como terapia de manutenção, principalmente porque os efeitos colaterais indesejáveis superam seus possíveis benefícios. Além disso, em um ano, menos da metade dos pacientes com colite ulcerativa que requerem corticosteróides terão resposta sustentada, aproximadamente um terço dos pacientes necessitarão de colectomia e um quarto não tolerarão a retirada do mesmo sem que apresentem recidiva da doença. Assim, dependência de corticóides em paciente com colite ulcerativa é problema clínico fundamental e manutenção da remissão sem esteróides é uma importante meta terapêutica no presente. Em pacientes com colite ulcerativa córtico-dependente, usualmente é colocado a escolha entre colectomia ou escalonamento do tratamento clínico, o qual tradicionalmente envolve a prescrição de droga imunossupressora. A terapia com tiopurinas tem tido amplo uso neste cenário na prática clínica. Entretanto, estudos avaliando a eficácia da azatioprina (AZA) na colite ulcertiva córtico-dependente são escassos. Os objetivos deste estudo foram avaliar em pacientes com colite ulcerativa dependente de esteróides, a eficácia da AZA na manutenção da remissão clínica sem esteróides, bem como os possíveis fatores associados à resposta sustentada a esta droga. Neste estudo de coorte observacional, pacientes adultos com colite ulcerativa dependente de esteróides foram recrutados para tratamento com AZA durante o período de 12 meses. AZA foi ajustada para a dose alvo de 2-3 mg/Kg/dia. A redução da dose de esteróides durante o estudo seguiu um esquema previamente padronizado. A avaliação primária de eficácia foi a taxa anual de pacientes que alcançaram resposta sustentada a AZA sem esteróides. Avaliações secundárias incluíram o número anual de recorrências clínicas, dose mediana de esteróides utilizadas durante o ano e segurança do tratamento. O total de 42 pacientes foi incluído. Na análise intenção de tratar, a proporção de pacientes permanecendo em remissão sustentada sem esteróides no final de 12 meses foi de 0,55. Observou-se significante redução na taxa de recorrências clínicas, assim como no requerimento de esteróides durante 12 meses de tratamento com AZA quando comparado com o ano anterior ao uso desta droga. (P=0,000 para ambas as comparações). Apenas a duração da doença < 36 meses antes do início da AZA foi associada à remissão clínica sem esteróides (P=0,02, OR 3,12 95% IC 1,89-7,64). AZA foi bem tolerada e o seu perfil risco-beneficio favorável. AZA mostrou eficácia sustentada para a manutenção da remissão clínica sem esteróides, bem como efeito poupador de esteróides durante 12 meses de terapia em pacientes com colite ulcerativa dependente de esteróides. Os pacientes com colite ulcerativa de início mais precoce são aqueles que mais provavelmente alcançarão remissão sustentada sem esteróides durante o uso de AZA. / Ulcerative colitis (UC) is a lifelong, immune-mediated inflammatory condition of the colonic mucosa, which is characterized by a relapsing and remitting course. Corticosteroids remain one of the most effective therapies for inducing remission in patients with moderate-to-severe UC. Nonetheless, corticosteroids are not used in maintenance therapy, mainly because undesirable side effects outweigh the possible benefits. Furthermore, at one year, less than half of UC patients who require steroids have a sustained response, nearly one-third of patients require colectomy, and approximately a quarter is unable to support its withdrawal without relapsing. Thus, corticosteroid dependence in patients with UC is a pivotal clinical problem and maintenance of steroid-free remission is an important current evolving treatment goal. Patients with steroid dependent UC are usually given a choice between colectomy or stepped-up medical treatment, which traditionally involves prescription of an immunosuppressive drug. Thiopurine therapy has found widespread use for this setting in clinical practice. However, studies assessing the efficacy of azathioprine (AZA) in steroid-dependent ulcerative colitis (UC) are scarce. The purpose of this trial was to explore the efficacy of AZA in maintaining steroid-free remission in steroid-dependent UC patients as well as the factors associated to sustained response. In this observational cohort study adult subjects with steroid-dependent UC were recruited for AZA therapy during a 12 months period. AZA was adjusted for a target dose of 2-3 mg/Kg/day. Steroid therapy was tapered off following a standardized regimen. The primary endpoint was the rate of patients with sustained steroid-free response to AZA at the end of 12 months. Secondary endpoints included clinical recurrence, yearly steroid dose, and safety of treatment. A total of 42 patients were included. On an intention-to-treat basis, the proportion of patients remaining in sustained steroid-free remission at 12 months was 0.55. A significant decrease in the flare-ups rate as well as in requirement for steroids were observed during 12 months while on AZA compared with the previous year (P=0.000). Only disease duration of <36 months before the initiation of AZA was associated to off-steroids remission (P=0.02, OR 3.12 (95% CI 1.89-7.64)). AZA was well tolerated and its benefit-risk profile favorable. AZA showed sustained efficacy for maintenance of clinical remission off steroids and steroid sparing through 12 months of therapy in patients with steroid dependent UC. Patients with earlier UC are those who most probably will have sustained steroid-free remission while on AZA.

Living with inflammatory bowel disease (IBD) affects physical, psychological and social dimensions, limiting the ability to engage in daily activities. Persons with IBD may need frequent and lifelong contacts with the healthcare (HC), highlighting the importance of quality care. High quality HC for persons with IBD involves a partnership between the HC professionals and the person living with the disease. Information is essential, the more a person knows about their disease, the more concordant and satisfied with their treatment they are likely to be. The overall aim of this thesis was to describe the knowledge need, life situation and perception of HC among persons living with IBD, in order to develop a questionnaire to evaluate the quality of HC. This thesis is based on three studies that are presented in four papers. Qualitative methods were used to describe aspects of life situation in relation to the disease, whereas quantitative method was used to develop a questionnaire measuring quality of care. Study I and II have an inductive qualitative design. In study I, qualitative interviews with 30 people were performed to describe the knowledge need and experience of critical incidents in daily life while living with IBD. The interviews in study I were analyzed using content analysis (results presented in Paper I) and critical incident technique (results presented in Paper II). In study II, the perceptions of HC among persons living with IBD was explored in five focus group interviews and two individual interviews, in total n=26. Study III aimed to develop and evaluate a questionnaire, measuring quality of care among persons with IBD, including 318 persons with IBD and 8 professionals. The knowledge need among persons with IBD focused on managing symptoms and course of the disease and learning to assimilate the information in order to manage everyday life. Losing bowel control was of great concern for most of the informants in the study. Many of the informants said that “the bowel ruled their life” and that it influenced them to a great extent in their daily lives. The perception of HC among persons with IBD meant being met with respect and mutual trust, receiving information at the right time, shared decision-making, competence and communication, access to care, accommodation, continuity of care and the pros and cons of specialized care. The quality of care questionnaire QoC-IBD was constructed in five dimensions, building on the results from Study I and II. The dimensions were trust and respect, decision-making, information, continuity of care and access to care consisting of 21 questions in total. QoC-IBD is a short, self-administrated questionnaire that measures experiences of healthcare among persons with IBD with promising validity and reliability. To improve quality of care, HC is recommended to consider individual care needs and take the person’s daily life and social context into account. The QoC-IBD questionnaire measures the subjective experience of quality of care. Further testing in clinical practice is necessary to evaluate if QoC-IBD can be used to evaluate the care given and areas of improvement in HC for persons living with IBD.

La rectocolite hémorragique (RCH) est une maladie inflammatoire chronique de l'intestin responsable d'un handicap et d'une altération de la qualité de vie pouvant exposer les patients à des complications sévères en dépit des thérapeutiques actuelles. L'objectif de cette thèse était d'analyser les voies possibles d'amélioration de la prise en charge thérapeutique des patients à partir de données expérimentales et cliniques. Au niveau expérimentale nous nous sommes intéressés au mécanisme impliqué dans la régulation de l'expression de PPARγ, récepteur nucléaires aux propriétés anti-inflammatoires, primitivement diminuée au cours de la RCH et cible des 5-aminosalicylés. Il a été montré que son expression était d'une part sous le contrôle de la stéroidogenèse intraépithéliale, elle-même sous contrôlée par LRH-1 et d'autre part que l'hypoxie épithéliale diminuait son expression via une sur-expression de miR-27a. Par ailleurs, les effets de l'hypoxie sur l'expression de PPARγ étaient inversés en présence de sildénafil. Sur le versant clinique, l'analyse d'une nouvelle stratégie thérapeutique ciblant la cicatrisation muqueuse, c'est à dire l'abrogation de l'inflammation colique macroscopique était efficace et possible dans la pratique clinique. Cet objectif semble aujourd’hui fondamental pour diminué la morbi-mortalité induite par cette maladie. Enfin nous avons observé l'efficacité des anti-TNF dans le cas spécifique de la rectite réfractaire et l'importance de son utilisation prolongée pour éviter les rechutes de la maladie et l’obtention d’une rémission prolongée. / Ulcerative colitis (UC) is a chronic disabling and relapsing inflammatory disease of the colonic mucosa that for more than half of patients results in chronic intermittent or continuous symptoms of increased stool frequency, fecal urgency and rectal bleeding The aim of the present work was to assess experimental ways and new therapeutic strategies with current treatments to improve long-term outcomes of UC. We focused experimental work on the peroxisome proliferator-activated receptor γ (PPARγ), a key factor of gut homeostasis and a target of mesalamine. The mechanism of primary impaired expression of PPARγ in colonic epithelial cells (CEC) during UC remains unknown. We demonstrated the control of PPARγ expression by intracellular CEC production of cortisol and the lack of cortisol production during UC that may participate towards the decreased expression of PPARγ. Furthermore hypoxia, a driver of mucosal inflammation during UC, markedly decreased PPARγ expression through the over-expression of miR-27a that was reversible by the use of sildenafil. From a clinic point of view, we assessed the efficacy and feasibility of a treat to target strategy which implies treatment optimization to achieve mucosal healing a key factor of long-term outcomes. Finally we addressed the long-term outcomes of patients treated with infliximab including the case of refractory proctitis.

La maladie de Crohn (MC) et la rectocolite hémorragique (RCH) sont les deux principales formes cliniques des maladies inflammatoires chroniques de l’intestin (MICI) responsables d’une atteinte inflammatoire de la paroi du tube digestif avec des ulcérations extensives. Ce sont des maladies fréquentes en Europe et en Amérique du Nord avec plus de 2.5 millions de malades. Du fait de l’augmentation importante de leur prévalence, de leur morbidité, du retentissement sur la qualité de vie des malades et du coût de leur prise en charge médicale, les MICI sont devenues un problème majeur de santé publique. Au cours de ces maladies, l’inflammation intestinale peut être contrôlée par les traitements médicamenteux ou la chirurgie sans pour autant obtenir de guérison complète et définitive. Bien que leur origine reste mal connue, l’hypothèse actuelle présente les MICI comme des maladies multifactorielles, secondaires à une réponse immunitaire muqueuse anormale dirigée contre la flore intestinale, survenant chez des individus génétiquement prédisposés et entrainant une inflammation intestinale. Le but du travail était d’explorer les mécanismes à l’origine de cette inflammation intestinale associée au développement des MICI en étudiant plus particulièrement certains facteurs environnementaux, moléculaires et microbiens. Nous avons étudiés tout d’abord l’aluminium comme facteur environnemental en démontrant qu’il pouvait participer au développement et à l’aggravation de l’inflammation intestinale sur des modèles de colite chez la souris. Nous avons ensuite étudié un facteur moléculaire important pour l’apoptose des cellules, la caspase-8. Nous avons montré que cette caspase-8 maintenait l’homéostasie intestinale des cellules épithéliales intestinales et que sont absence entraînait une inflammation intestinale ressemblant à la maladie de Crohn. Finalement nous nous sommes intéressés à un facteur microbien, Saccharomyces cerevisiae CNCM I-3856 qui est une levure. Nous avons démontré que cette levure était capable d’induire un effet anti-inflammatoire et analgésique chez l’animal en activant PPAR&#947; dans le colon. Chez l’homme nous avons montré dans une étude randomisée que Saccharomyces cerevisiae CNCM I-3856 réduisait les douleurs abdominales chez les patients atteints du syndrome de l’intestin irritable. En conclusion, l’exploration de ces trois facteurs environnementaux, moléculaires et microbiens permet de mieux comprendre le développement de l’inflammation intestinale. La perspective de ce travail est le développement dans un futur proche des nouvelles thérapeutiques ciblées permettant de lutter contre l’inflammation intestinale. / Crohn's disease (CD) and ulcerative colitis (UC) are the two main clinical forms of chronic inflammatory bowel disease (IBD) responsible for intestinal inflammation with extensive ulceration of the mucosa. These are common diseases in Europe and North America with over 2.5 million patients. Due to the significant increase in their prevalence, their morbidity, the impact on quality of life of patients and the cost of their medical care, IBD has become a major public health problem. In these diseases, intestinal inflammation may be controlled by drug treatment or surgery without obtaining a complete and final cure. Although their origin remains unclear, the current hypothesis presents IBD as multifactorial diseases secondary to an abnormal mucosal immune response directed against the intestinal flora, occurring in genetically predisposed individuals and causing intestinal inflammation. The aim of this work was to explore the mechanisms behind this intestinal inflammation associated with the development of IBD studying some particular environmental, molecular and microbial factors. We studied first the aluminum as an environmental factor and demonstrated that he could participate in the development and exacerbation of intestinal inflammation in models of colitis in mice. We then studied an important factor in molecular cell apoptosis, caspase-8. We have shown that caspase-8 was maintaining intestinal homeostasis in intestinal epithelial cells and that absence of caspase-8 leads to intestinal inflammation mimicking Crohn's disease. Finally we studied a microbial factor, Saccharomyces cerevisiae CNCM I-3856 which is yeast. We demonstrated that this yeast was capable of inducing an anti-inflammatory and analgesic effect in animals by activating PPARgamma in the colon. In humans we have shown in a randomized study that Saccharomyces cerevisiae CNCM I-3856 reduced abdominal pain in patients with irritable bowel syndrome. In conclusion, the exploration of these three environmental molecular and microbial factors helps to better understand the development of intestinal inflammation. The perspective of this work is the development in the near future of new targeted therapies directed against intestinal inflammation.

The objectives of this thesis were to synthesize existing RCT evidence and post-market observational evidence of TNF-α inhibitors in IBD. Two separate systematic reviews were performed: an overview of systematic reviews of RCTs, and a systematic review of post-market observational studies of TNF-α inhibitors in Crohn’s disease and ulcerative colitis. The overview of systematic reviews included 37 studies. RCT evidence demonstrated superiority of all agents to placebo in Crohn’s disease and ulcerative colitis, with no increased risk of malignancy or serious adverse events. Network meta-analyses have not shown superiority of any agent compared to another. The second systematic review included 255 studies. Included studies were deemed to be unamenable to pooling with substantial methodological and clinical diversity. Available evidence is insufficient to determine whether real-world effectiveness and safety is consistent with RCTs, but suggests no increased risk of malignancy and no difference in efficacy between adalimumab and infliximab.

Inflammatory bowel disease (IBD), which includes the subtypes Crohn's disease (CD) and ulcerative colitis (UC), is a common disease particularly in the Western world. IBD is characterised by inflammation of the small intestine and/or colon. The two subtypes affect different gut locations but both show an increased intestinal permeability or the 'leaky gut syndrome'. This led to the hypothesis that tight junction (TJ) proteins expressed in the epithelium may affect the intestinal permeability as a cause or effect of IBD.Initially, variants in the CARD15, IL23R and ATG16L1 genes, previously associated with an increased risk of IBD, were genotyped in a cohort of 500 IBD (295 CD and 205 UC) patients and 877 matched controls. These variants were significantly associated in our cohort. A random effects meta-analysis was undertaken on all previously reported CD associations with the variant rs2241880 from ATG16L1 (n=25, p=0.0017, OR: 1.36 95% CI 1.12-1.66) and with rs11209026 from IL23R (n=26, p=0.0006, OR: 0.37 95% CI 0.21-0.67), showing pooled odds ratios consistent with those reported in our cohort. Individuals carrying >1 CARD15 mutant variant were found to have a 2.5 fold increased risk of CD (p=0.0001). Candidate TJ proteins were chosen on the basis of previous reported associations and through the investigation of the claudin proteins which are abundant at TJs. Twenty one candidate genes were selected and 79 variants successfully genotyped in up to 1063 IBD (502 CD and 478 UC) and 870 control patients. Significant associations were detected with variants in the CLDN1, CLDN5 and CDH1 genes with CD; CLDN5, CLDN8 and CDH1 variants were associated to IBD; and the rs7791132 variant (between CLDN4 and ELN) and a CDH1 variant were associated to UC. The CLDN1 rs6809685 variant trended towards association in a Toronto ascertained IBD replication cohort (genotypic p=0.04, allelic p=0.06) suggesting this may be a novel IBD susceptibility variant. Small intestinal biopsies from CD patients with known rs6809685 genotypes showed a dose dependent reduced immunohistochemical staining of claudin 1 with carriage of the mutant G allele. Claudin 1 helps seal TJs and reduced levels may increase risk of CD.Peroxisome proliferator activator receptors (PPARs) can directly affect TJ proteins and could therefore affect intestinal permeability. Twelve PPARγ variants were genotyped in up to 1050 IBD (502 CD and 467 UC) and 725 control patients. Significant genotypic associations were found with the rs2067819 variant in CD (p=0.05) and IBD (p=0.02), and also the rs13099634 variant in UC (P=0.02). There was a strong gender difference particularly for rs2067819 and rs4135247, where allelic associations were highly significant and increased risk of IBD in men (p=0.01 and p=0.007 respectively). However no significant associations were found in the female cohort. Troglitazone a PPARα agonist increased Caco2 cell transepithelial electrical resistance (TEER), a marker of TJ integrity, and increased expression of claudins -3 and -4. In contrast, the PPARα antagonist GW6471 reduced the TEER without causing cell death and PPARγ ligands did not affect TEER measurements. In summary, using a robust cohort of cases and controls the data indicates that variants in genes encoding TJ proteins may affect susceptibility to IBD and that PPARs can regulate these proteins altering intestinal permeability.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-01-21T16:51:59Z No. of bitstreams: 1 carlavaleriadealvarengaantunes.pdf: 1487917 bytes, checksum: c0d630797135f7fb32b18c3ae9000d7c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T18:46:52Z (GMT) No. of bitstreams: 1 carlavaleriadealvarengaantunes.pdf: 1487917 bytes, checksum: c0d630797135f7fb32b18c3ae9000d7c (MD5) / Made available in DSpace on 2016-01-25T18:46:52Z (GMT). No. of bitstreams: 1 carlavaleriadealvarengaantunes.pdf: 1487917 bytes, checksum: c0d630797135f7fb32b18c3ae9000d7c (MD5) Previous issue date: 2014-07-10 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Anemia de difícil tratamento é uma manifestação clínica comumente observada nos pacientes portadores de doenças inflamatórias intestinais, sendo responsável por prejuízo significativo na qualidade de vida destes pacientes. O objetivo deste estudo foi avaliar, nos pacientes com doença inflamatória intestinal, a prevalência e os fatores de risco da anemia suas possíveis etiologias. Neste estudo de corte prospectivo observacional foram recrutados: 100 pacientes portadores de Doença de Crohn e 100 pacientes portadores de Retocolite ulcerativa, diagnosticados e acompanhados regularmente no Centro de Doenças Inflamatórias Intestinais do Hospital Universitário da Universidade Federal de Juiz de Fora, para avaliação hematológica, bioquímica e imunológica. Foram obtidas amostras de sangue (20 ml) e realizados os seguintes exames em todos os pacientes: hemograma completo, VGM, HGM, CHGM, plaquetas, ácido fólico, vitamina B12, reticulócitos, índice de saturação da transferrina, ferritina, ferro sérico, PCR e VHS. Foram adotados para o diagnóstico de anemia os mesmos critérios da WHO (World Health Organization). Foi considerado Anemia por Deficiência de Ferro quando houve diminuição dos níveis séricos de ferro (< 37 μg/dl para mulheres e < de 59 μg/dl para homens), da ferritina (<30μg/l- na ausência de dados clínicos, laboratoriais ou endoscópicos de inflamação intestinal e < 100 μg/l - na presença de quaisquer destes dados), do índice de saturação da transferrina (<16%). Foi considerado Anemia da Doença Crônica quando houve diminuição dos níveis séricos de ferro (< 37 μg/dl para mulheres e < de 59 μg/dl para homens), aumento da ferritina (>100μg/l) e diminuição do índice de saturação da transferrina (<16%). - na presença de dados clínicos, laboratoriais ou endoscópicos de inflamação intestinal e Anemia Mista quando houve diminuição dos níveis séricos de ferro (< 37 μg/dl para mulheres e < de 59 μg/dl para homens) e ferritina entre 30 e 100μg/l. As anemias foram classificadas em hiporregenerativas quando a contagem absoluta de reticulócitos estava abaixo de 50000 e normoproliferativas ou normorregenerativas quando a contagem absoluta de reticulócitos estava acima de 100000/mm³. / Anemia difficult to treat is a clinical manifestation commonly seen in patients with inflammatory bowel disease , being responsible for significant impairment in quality of life of these patients. The aim of this study was to evaluate, in patients with inflammatory bowel disease, the prevalence and factors risk of anemia and possible etiologies of anemia in their possible occurrence. In this cross-sectional study of adult patients with inflammatory bowel disease (IBD) were recruited, of which: 100 patients with Crohn's disease and 100 patients with ulcerative colitis, diagnosed and regularly followed at the Center for Inflammatory Bowel Diseases , University Hospital, Federal University of Juiz de Fora , for haematological, biochemical and immunological evaluation. Blood samples ( 20 ml ) were obtained and the following examinations were performed in all patients: CBC, MCV, MCH , CHCM , platelets , folic acid, vitamin B12 , reticulocytes , transferrin saturation index , ferritin , serum iron, CRP and ESR . For the diagnosis of anemia the same criteria of WHO (World Health Organization) were adopted . Was considered Iron Deficiency Anemia when there was a decrease in serum iron levels ( < 37 mg / dl for women and < 59 g / dl for men ) , ferritin (< 30μg/l - in the absence of clinical, laboratory data or endoscopic intestinal inflammation and <100 mg / l - in the presence of any of these data) , the ratio of transferrin saturation (<16 %). Anemia was considered the Crohnic Disease Anemia when there was a decrease in serum iron levels (< 37 mg / dl for women and < 59 g / dl for men), elevated ferritin ( > 100μg / l ) and decreased transferrin saturation index (<16 %). - in the presence of clinical, laboratory and endoscopic data of intestinal inflammation and Mix Anemia when there was a decrease in serum iron levels ( < 37 mg / dl for women and < 59 g / dl for men) and ferritin between 30 and 100μg / l . Anemia were classified into hiporregenerative when absolute reticulocyte count was below 50,000 and normoproliferative or normorregenerative when the absolute reticulocyte count was above 100,000.

Pretendeu-se, no presente estudo, verificar a segurança e a eficácia do transplante de células-tronco derivadas do tecido adiposo (ASC) em ratos com UC induzida por ácido trinitrobenzenosulfonico (TNBS). A população celular foi isolada do tecido adiposo por dissociação mecânica e cultivada. O comportamento celular foi verificado por meio da morfologia, proliferação, viabilidade, capacidade de aderência à superfície plástica e parâmetros de diferenciação osteogênica, condrogênica e adipogênica. Os animais foram avaliados, considerando-se os aspectos clínicos, macroscópicos, microscópicos e bioquímicos. No modelo experimental de UC, a infusão de ASC reduziu significativamente a presença de aderências entre o cólon e órgãos adjacentes, bem como diminuiu a quantidade de células inflamatórias na mucosa lesada. Conclui-se que as ASC podem promover e/ou acelerar o processo de regeneração da mucosa intestinal inflamada e assim, serem empregadas como uma opção terapêutica com amplo potencial de aplicabilidade no tratamento da DII. / It was intended in this study verify the safety and efficacy of the transplantation of adipose derived stem cells (ASC) in rats with ulcerative colitis induced by trinitrobenzenosulfonico acid (TNBS). The cell population was isolated from the adipose tissue by mechanical dissociation and cultured. The cell behavior was verified by the morphology, proliferation, viability, ability to adhere to the plastic surface and parameters of osteogenic differentiation, adipogenic and chondrogenic. The animals were evaluated, considering the aspects clinical, macroscopic, microscopic and biochemical. In experimental ulcerative colitis, infusion of ASC significantly reduced the presence of adhesions between the colon and adjacent organs and decreased the amount of inflammatory cells in the injured mucosa. It is concluded that the ASC can promote and/or accelerate the healing process of the intestinal mucosa inflamed and thus be employed as a therapeutic option with wide potential application in the treatment of IBD.

Les maladies inflammatoires chroniques de l'intestin (MICI) désignent deux affections, la maladie de Crohn (MC) et la rectocolite hémorragique (RCH). Ces maladies sont caractérisées par une grande disparité de répartition dans le monde et une forte augmentation de leur incidence depuis 50 ans. Leur physiopathologie fait intervenir une composition anormale du microbiote intestinal (appelée dysbiose), une dysfonction de la barrière épithéliale, un déficit de l'immunité innée et une dérégulation de l'immunité adaptative. Plus de 163 gènes de prédisposition ont été identifiés, mais la plupart d'entre eux ne sont associés qu'à une augmentation modeste du risque de MICI (Odds Ratios compris entre 1,02 et 1,2). Les facteurs d'environnement semblent jouer un rôle important dans la survenue de ces maladies. Le tabagisme a un effet démontré, favorable dans la RCH, néfaste dans la MC. L'exposition solaire, la vitamine D, l'alimentation, les agents infectieux et les médicaments ont été associés aux MICI mais leur effet est moins bien démontré. Cette thèse d'épidémiologie est consacrée aux MICI; plus précisément, à l'étude de leurs facteurs d'environnement, et au risque de cancer associé aux médicaments des MICI. Elle est fondée sur l'étude de bases de données françaises et européennes. Un premier travail a exploré l'association entre l'exposition à l'isotrétinoïne (médicament prescrit pour traiter l'acné) et la survenue de RCH, rapportée par une étude américaine. Cette étude cas témoin a été menée à l'échelle de la France entière à partir des données du système national d'information inter-régimes de l'assurance maladie (SNIIRAM). Dans ce travail très peu de patients atteints de MICI ont reçu de l'isotrétinoïne durant l'année précédant le diagnostic de la maladie. La prise d'isotrétinoïne n'est pas associée au risque de RCH mais inversement associée au risque de MC.Dans un deuxième travail, nous avons étudié l'impact gobal de l'alimentation en modélisant les profils alimentaires associés à la survenue de RCH et de MC dans la cohorte prospective européenne EPIC (European Prospective Investigation Into Cancer). Un profil alimentaire riche “en produits sucrés et sodas” est associé à l'incidence de RCH dans le sous-groupe diagnostiqué au delà de 2 ans. Aucun profil alimentaire n'est associé au risque de MC. Le régime méditerranéen n'est ni associé à la RCH ni à la MCDans un troisième travail, nous nous sommes intéressés aux risques de cancer associés à l'exposition aux médicaments des MICI : immunosuppresseurs et anti-TNF. Leur prescription a beaucoup augmenté ces dernières années. Cependant ils ont été associés à un risque de lymphome, de cancer de la peau non mélanocytaire et de mélanome pour les thiopurines et les anti-TNF, respectivement. Nous avons évalué prospectivement le risque de cancer associé à ces médicaments, à l'échelle de la France entière dans des conditions de prescription courante, grâce aux données du SNIIRAM. Les résultats sont en en cours d'analyse.Notre thèse montre que l'étude des bases de données peut apporter une réponse à une question importante en pratique clinique , portant sur le lien entre isotrétinoïne et MICI. Notre travail a également permis de générer des hypothèses sur le lien entre les profils alimentaires et la survenue de MICI. Les limites de l'exercice (détaillées dans le manuscrit) ne doivent pas être sous estimées. Nos résultats suscitent des questions et appellent d'autres travaux, menés à une échelle encore plus vaste et avec d'autres méthodes statistiques. / Inflammatory bowel diseases refer to two conditions: Crohn's disease and ulcerative colitis. These diseases display an important geographic heterogeneity worldwide and an increase in incidence during the last fifty years. Their physiopathology is complex, involving anormal composition of gut microbiota (dysbiosis), dysfonction of epithelial barrier and dysregulation of innate and adaptative immune response. More than 163 predisposing genes have been identified, but most of them carry modest association with IBD (Odds ratios varrying from 1.02 to 1.3) (1–3). Environmental factors seem to play an important role in IBD onset. Smoking has a positive effect on UC and harmfull effect on CD. Sun exposure, vitamin D, diet, infections have been inconsistently associated with IBD. This epidemiology thesis is devoted to IBD and specifically, to environemental risk factors, and also to the risk of cancer associated to IBD drugs. It is based on French and European databases. Our first work, explored the association between isotretinoin and UC reported in a US study. Our study was performed in a case-control study in the whole French territory thanks to a medico-administrative database (SNIIRAM). In this work, only a few patients with IBD were exposed to isotetinoin in the year before disease onset. Exposure to isotretinoin was not associated with UC but negatively associated with CD.In a second study, we explored the global impact of diet on UC and CD in a European prospective study (European Prospective Investigation Into Cancer (EPIC)). A dietary pattern with “high sugars and soft drinks” was associated with UC risk when restricted to cases diagnosed at least two years after dietary assessment. No dietary pattern was associated with CD. Mediterranean diet had no effect on UC nor CD risks.In the third part of this work, we investigated the risk of cancer associated with IBD drugs: immunosuppresive agents and anti-TNF. These medications are more and more prescribed nowadays. Howevere, they are associated with an increased risk of cancer in observationnal studies: lymphoma and non melanoma skin cancer with thiopurines and anti-TNF agents respectively. Therefore, we aimed to investigate the cancer risks associated with thiopurine and/or anti-TNF exposure in the whole French territory in the real life , using a medico-adminstrative database (SNIRAM). Currently, we are still analyzing the results.Our work shows that studying large databases can answer an important issue in clinical practice related to a potential link between isotretinoin and IBD. Also, it has generated hypotheses about the link between dietary pattern and IBD. Limitations of our work (detailed in the manuscript) should be considered.. Otr studies using larger databases and other statistical methods should address these limitations.

Gut microbiota is considered an important factor in the development of various diseases including inflammatory bowel disease (IBD, n = 127), Ulcerative colitis, Crohn's disease, and colorectal cancer (CRC, n = 64). A part of this thtesis is to prepare clinical material of different sorts (stool, biopsy) for sequencing on Illumina Miseq platform. This is achieved trough DNA isolation, amplification of 16S and internal transcribed spacer (ITS), normalization and ligation of sequencing adaptors. The aim of this project is to describe the differences between microbiota in healthy and diseased subjects in case of IBD or unimpaired and tumorous tissue for CRC patients. This research is also being based on cultivation, where a fresh stool samples (n = 3) are cultivated in a broad range of conditions, which enables us to obtain ecophysiological and species diversity of these samples by traditional and molecular methods. The cultivable fungi are also assigned reliable taxonomy by amplification of relevant genes (ITS1, β tubulin, second largest subunit of RNA polymerase II, RPB2) followed by both-sided Sanger sequencing. Selected species of fungi are processed into lysates, which are used for stimulation of mice macrofage cell line (RAW). Therefore the impact on immunity response is studied in vitro and...