La Broncho-Pneumopathie chronique obstructive (BPCO) est un problème majeur en santé publique puisque ce sera la 3ème cause de mortalité en 2020. Il s'agit d'une maladie inflammatoire chronique du poumon se traduisant par une obstruction progressive des bronches, partiellement ou non réversible, incluant bronchite chronique, hypersécrétion de mucus et emphysème. L'atteinte ne se limite pas au poumon et affecte d'autres organes dont le tube digestif en favorisant la maladie de Crohn. Le premier facteur de risque impliqué dans le développement de cette maladie est l’exposition à la fumée de cigarette qui induit un stress oxydatif au sein du poumon responsable d'une inflammation chronique et du développement de la BPCO. L'interleukine-17 joue un rôle essentiel dans ce processus en contrôlant l'inflammation et l'altération de la fonction respiratoire. L'objectif de cette thèse est de comprendre les facteurs contrôlant cette réponse IL-17 afin de proposer ensuite de nouvelles voies thérapeutiques. Dans la première partie, nous nous sommes focalisés sur le stress oxydatif et à son impact sur les cellules de l’immunité innée. Ensuite, nous abordons le rôle d'un facteur immunorégulateur, l'IL-10, et à son interférence avec le microbiote digestif. Cela nous a amené à nous intéresser aux lésions digestives associées au tabagisme. Un modèle murin d’exposition chronique à la fumée de cigarette a été développé afin de reproduire la physiopathologie de la BPCO. Concernant l'impact du stress oxydatif, nous avons étudié le rôle des cellules iNKT (cellules ayant un puissant potentiel dans l’immunorégulation et dans l’inflammation) qui sont activées par ce type de stress. Les cellules iNKT sont rapidement recrutées et activées au sein du poumon suite à l’exposition à la fumée de cigarette. En utilisant des souris déficientes, nous avons montré l’importance de ces cellules dans la physiopathologie de la BPCO. Cette pathogénicité est dépendante de la production de l’interleukine-17 par ces cellules et est initiée par le stress oxydatif sur les cellules épithéliales pulmonaires et les cellules dendritiques qui activent les cellules iNKT.Dans la seconde partie du projet, l’IL-10 intervient notamment dans le contrôle de l'inflammation afin d’éviter le développement de réponses immunologiques exacerbées dans certains contextes. Dans les poumons exposés à la fumée de cigarette, la production d’IL-10 est augmentée et la déficience pour cette cytokine entraîne une augmentation de la réponse Th17 et du déclin de la fonction pulmonaire. Une dysbiose (altération du microbiote) est observée avec la fumée de cigarette et la déficience à l'IL-10. De plus, une déplétion des bactéries Gram+ par antibiothérapie permet de limiter le développement de la réponse IL-17 et de l'atteinte pulmonaire soulignant l'importance du microbiote. En conclusion, nous avons identifié le stress oxydatif et l'IL-10 comme facteurs intervenant dans la réponse IL-17 associé à la BPCO. Ce travail souligne également le rôle du microbiome comme un organe à part entière et la modulation de ce dernier pourrait aboutir à l'identification de nouvelles voies thérapeutiques. / Chronic Obstructive Pulmonary Disease (COPD) is a major health problem which is going to become the third leading cause of death worldwide by 2020. COPD is characterized by a chronic inflammation of the airways causing progressive bronchial obstruction, with no completely reversible airflow limitation, including chronic bronchitis, mucus hypersecretion and emphysema. The pathology is not limited to the airways and can affect others organs including the gastro-intestinal tract promoting Crohn disease. Cigarette smoke exposure is the most important risk factor for developing COPD. Exposure to cigarette smoke induces a strong burden of reactives oxygen species and this oxidative stress is responsible for a chronic inflammation and the development of COPD. Interleukin (IL)-17 plays a critical role in controlling process of inflammation and lung function decline.The aim of this thesis is the understanding which factors are controlling the IL-17 response in order to propose new therapeutic approaches.In the first part, we focused on oxidative stress and its impact on innate immune cells. Then we addressed the role of an immunoregulatory factor, the interleukin (IL)-10, and its interference with intestinal microbiota. This part lead us to study intestinal damages linked to cigarette smoking.To mimic the physiopathology of COPD, we set up a mouse model of chronic exposure to cigarette smoke. Concerning the impact of oxidative stress, we investigated the role of iNKT cells (cells with a crucial potent role in immunoregulation and inflammation) activated by this type of stress. iNKT cells rapidly accumulate and be activated within the lungs of cigarette smoke exposed mice. Using deficient mice, we demonstrated that these cells strongly contribute to the COPD pathogenesis. This pathogenicity is iNKT cells-produced IL-17 dependant and initiated by the effect of oxidative stress on airway epithelial cells and dendritic cells activating iNKT.In the second part of the work, IL-10 interferes notably in the inflammation control in order to avoid exacerbated immunological responses development in some contexts. In cigarette smoke exposed lungs, IL-10 production is up-regulated and the deficiency for this cytokine leads to an increased Th17 response and to lung function decline. An altered microbiota (named dysbiosis) is observed with cigarette smoke exposure and IL-10 deficiency. Moreover, Gram+ bacteria depletion using antibiotics is able to limit the IL-17 response development and the lung function decline highlighting the crucial role for microbiota.To conclude, we identified two factors, oxidative stress and IL-10, implicated in IL-17 response linked to COPD. This work also underlines the role of microbioma as a whole organ and the modulation of this microbioma could result in new therapeutic ways identification in COPD.

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.

A doença inflamatória intestinal (DII) e a esclerose sistêmica (ES) são doenças inflamatórias crônicas de difícil diagnóstico e tratamento. A etiologia da DII e da ES ainda não é completamente compreendida, mas sabe-se que fatores genéticos, imunológicos e ambientais estão envolvidos na sua patogênese. A DII possui dois principais subtipos clínicos: a doença de Crohn (DC) e a retocolite ulcerativa (RCU), caracterizados pela inflamação do intestino delgado e/ou cólon. Evidências sugerem que o aumento do estresse oxidativo desempenha um papel importante na fisiopatologia da DII. A ES é uma doença inflamatória autoimune rara, caracterizada pela fibrose progressiva da pele e de órgãos internos. A hipótese de que o aumento do dano oxidativo pode iniciar o dano vascular e desencadear os eventos patológicos observados na ES vem sendo investigada. Genes e enzimas envolvidos na metabolização (Fase I) e detoxificação (Fase II) de xenobióticos são utilizados como marcadores de susceptibilidade para o desenvolvimento de doenças que possuem fatores ambientais como fatores de risco. Em uma reação de Fase I, as enzimas do Citocromo P450 (CYP) inserem um átomo de oxigênio em um substrato deixando-o eletrofílico e reativo, criando um sítio para posterior conjugação pelas enzimas de Fase II. As enzimas Glutationa S-tranferases (GST) de Fase II catalisam a conjugação da glutationa com uma grande variedade de compostos eletrofílicos, detoxificando substâncias endógenas e exógenas. A atividade catalítica aumentada das enzimas CYP, bem como a falha na detoxificação de metabólitos pelas GST pode contribuir para o aumento do estresse oxidativo. O objetivo deste estudo foi investigar o papel de polimorfismos nos genes que codificam enzimas de metabolização (CYP1A*2C e CYP2E1*5B) e detoxificação (GSTT1 nulo, GSTM1 nulo e GSTP1 Ile105Val) na susceptibilidade a estas doenças. O grupo de pacientes com DII era constituído por 235 indivíduos e o grupo controle por 241 indivíduos, todos eurodescendentes. Na ES, 122 pacientes (99 eurodescendentes e 23 afrodescendentes) e 329 controles (241 eurodescendentes e 87 afrodescendentes) foram analisados. Os polimorfismos CYP foram genotipados por PCR-RFLP, enquanto que os polimorfismos em GSTT1 e GSTM1 foram genotipados por PCR multiplex e PCR-RFLP para GSTP1. As frequências alélicas e genotípicas foram comparadas entre pacientes e controles usando o teste de Qui-Quadrado. A respeito dos resultados das análises em DII, as frequências alélicas e genotípicas dos polimorfismos CYP1A1*2C, CYP2E1*5B e GSTP1 Ile105Val, bem como as frequências genotípicas do polimorfismo de presença/ausência de GSTM1, foram similares nos três grupos de pacientes (DII, DC e RCU) quando comparados ao grupo controle (P>0,05). Observouse uma frequência significativamente aumentada do genótipo nulo de GSTT1 no grupo de pacientes com DII quando comparado ao grupo controle [0,28 vs 0,18; χ² com Yates P=0,02; OR=1,71 (IC 95% 1,09 –2,71)]. Quando separamos o grupo de pacientes em DC ou RCU, esta frequência permaneceu significativamente aumentada somente no grupo de pacientes com RCU comparado ao grupo controle [0,29 vs 0,18; χ² com Yates P=0,035; OR=1,84 (IC 95% 1,03 –3,24)]. Com relação aos resultados das análises na ES, uma frequência significativamente aumentada do genótipo *1A/*1A (P=0,03; 0,74 vs. 0,61) e do alelo *1A (P=0,013; 0,86 vs 0,78; OR=0,57, IC 95% 0,36–0,90) do polimorfismo CYP1A1*2C foi observada entre os indivíduos controles eurodescendentes. Em contrapartida, a frequência do alelo *2C estava significativamente aumentada entre os pacientes de mesma etnia (P=0,013; 0,22 vs 0,14; OR=1,75, IC 95% 1,11–2,74). Com relação às frequências alélicas e genotípicas dos polimorfismos CYP2E1*5B e GSTP1 Ile105Val, e as frequências genotípicas do polimorfismo de presença/ausência de GSTM1, nenhuma diferença significativa foi observada quando os grupos de pacientes de ambas as etnias foram comparados aos grupos controle (P>0,05). Uma frequência significativamente aumentada do genótipo nulo de GSTT1 [0,29 vs 0,18; χ² com Yates P=0,035; OR=1,85 (IC 95% 1,03–3,29)], bem como uma alta frequência da dupla deleção de GSTT1/GSTM1 [0,19 vs 0,08; χ² com Yates P=0,007; OR=2,62 (IC 95% 1,25 –5,46)], foi observada no grupo de pacientes comparado aos controles (eurodescendentes). Estas associações não se repetiram entre indivíduos afrodescendentes. Concluindo, nossos resultados sugerem que o genótipo nulo de GSTT1 está associado à susceptibilidade a DII e pode influenciar na definição do curso da doença para a RCU. Além disso, o genótipo nulo de GSTT1 sozinho ou em combinação com o genótipo nulo de GSTM1 é um fator genético de susceptibilidade para a ES, enquanto que o genótipo *1A/*1A ou a presença do alelo *1A do polimorfismo CYP1A1*2C pode exercer um papel protetor contra o desenvolvimento da ES em indivíduos eurodescendentes. / Inflammatory bowel disease (IBD) and systemic sclerosis (SSc) are chronic inflammatory diseases of difficult diagnosis and treatment. The etiology of IBD and SSc is not completely understood but it is known that genetic, immunologic and environmental factors are involved in its pathogenesis. Crohn’s disease (CD) and ulcerative colitis (UC) are the two major subtypes of IBD, characterized by inflammation of the small intestine and/or colon. Evidences suggest that the increase of oxidative stress plays an important role in the pathophysiology of IBD. SSc is a rare autoimmune inflammatory disease of the connective tissue characterized by progressive fibrosis of the skin and internal organs. The hypothesis that the increase of oxidative stress can initiate vascular damage and triggers the pathological events in SSc has been investigated. Genes and enzymes involved in metabolism (Phase I) and detoxification (Phase II) of xenobiotics are used as markers of susceptibility to the development of diseases that have environmental factors as risk factors. In a Phase I reactions, the Cytochrome P450 (CYP) enzymes insert an oxygen atom in a substrate that making it more electrophilic and reactive, and creating a site for subsequent conjugation by Phase II enzymes. Phase II Glutathione S-transferases (GSTs) enzymes catalyze the conjugation of glutathione with a variety of electrophilic compounds, detoxifying endogenous and exogenous substances. A higher catalytic activity of CYP enzymes, as well as the failure in detoxifying of metabolites by GST enzymes may to contribute for the increase of oxidative stress. The aim of this study was investigated the role of polymorphisms in genes coding Phase I enzymes (CYP1A*2C and CYP2E1*5B) and Phase II (GSTT1 null, GSTM1 null and GSTP1 Ile105Val) in susceptibility to these diseases. IBD group was constituted by 235 patients and the control group by 241 individuals, all European-derived. In SSc group, 122 patients (99 European-derived and 23 African-derived) and 329 controls (241 European-derived and 87 African-derived) were analyzed. The CYP polymorphisms were genotyped by PCR-RFLP, whereas polymorphisms in GSTM1 and GSTT1 were genotyped by multiplex PCR and PCRRFLP for GSTP1. Allelic and genotypic frequencies were compared between patients and controls using the Chi-square test. Concerning IBD, allelic and genotypic frequencies of CYP1A1*2C, CYP2E1*5B and GSTP1 Ile105Val polymorphisms, as well as genotypic frequencies of GSTM1 presence/absence polymorphism were similar in all groups patients (IBD, CD, and UC) and controls (P>0.05). We observed a significantly increased frequency of GSTT1 null genotype in IBD group as compared to controls [0.28 vs. 0.18, χ ² with Yates P=0.02, OR=1.71 (95% CI 1.09 – 2.71)]. When patients were classified in CD or UC group, this frequency remained significantly increased only among UC patients [0.29 vs. 0.18, χ ² with Yates P=0,035, OR=1.84 (95% CI 1.03 – 3.24)] as compared to controls. Regarding results in SSc, a frequency significantly increased of *1A/*1A genotype (P=0.03; 0.74 vs. 0.61) and *1A allele (P=0.013; 0.86 vs 0.78; OR=0.57, 95% CI 0.36–0.90) from CYP1A1*2C polymorphism was observed among European-derived controls. On the other hand, the frequency of *2C allele was significantly increased among patients of same ethnic group (P=0.013; 0.22 vs 0.14; OR=1.75, 95% CI 1.11–2.74). The allelic and genotypic frequencies of CYP2E1*5B and GSTP1 Ile105Val polymorphisms, as well as genotypic frequencies of GSTM1 presence/absence polymorphism were similar between SSc patients and controls of both ethnic groups (P>0.05). We observed a significantly increased frequency of GSTT1 null genotype [0.29 vs. 0.18, χ ² with Yates P=0.035, OR=1.85 (95% CI 1.03–3.29)], as well as an increased frequency of GSTT1/GSTM1 double-null in SSc patients as compared to controls [0.19 vs. 0.08; χ ² with Yates P=0.007, OR=2.62 (95% CI 1.25 – 5.46)]. These associations were exclusive to European-derived individuals. In conclusion, our results suggest that the GSTT1 null genotype is associated with susceptibility to IBD and may influence in defining the course of the disease for RCU. Furthermore, the GSTT1 null genotype alone or combined with GSTM1 null genotype is a susceptibility genetic factor to SSc, while the *1A/*1A genotype or the presence of *1A allele from CYP1A1*2C polymorphism may plays a protector role in SSc development in Brazilian Europeanderived individuals.

As Doenças Inflamatórias Intestinais (DII) são caracterizadas por resposta inflamatória exacerbada na mucosa intestinal, com desbalanço entre mecanismos pró-inflamatórios e reguladores. Entretanto, até o momento, nenhuma terapia é curativa e vários pacientes são refratários ou intolerantes a elas, necessitando de intervenções cirúrgicas para combater as complicações da doença. Sendo assim, é evidente que novas terapias são necessárias para o controle da progressão das DII. Dessa forma, como a saliva de insetos hematófagos constitui uma fonte importante de moléculas com potencial farmacológico, o objetivo desse trabalho foi avaliar a atividade terapêutica do extrato de glândula salivar (EGS) do Aedes aegypti e suas frações na colite experimental. Para tal, camundongos C57BL/6 foram submetidos à indução de colite pela administração de água contendo 3% de dextran sulfato de sódio (DSS). Os resultados demonstraram melhora na condição clínica e no escore pós-morte dos camundongos tratados com o EGS i.v. ou i.p. Essa melhora foi acompanhada de redução de leucócitos no sangue periférico, principalmente quando os animais foram tratados i.v. Além disso, redução do infiltrado inflamatório e das citocinas patogênicas IL-12, IFN-?, TNF-?, IL- 1? e IL-5, no intestino, foi também associada ao tratamento. Ademais, houve diminuição da frequência de linfócitos TCD4+ produtores de IFN-?, IL-17 e IL-4 no baço e nos linfonodos mesentéricos (LNM) dos animais tratados com EGS. Ainda, uma menor frequência de células CD11b+ no baço e CD49b+ nos LNM também foi detectada nos animais com inflamação intestinal tratados com o EGS. De forma interessante, quando expostos por dois ciclos ao DSS, o tratamento precoce com EGS (1o ciclo) protegeu os camundongos do desenvolvimento da colite após nova indução da inflamação intestinal (2o ciclo), sugerindo que a saliva do A. aegypti possui componentes com capacidade de retardar o aparecimento e a gravidade da recidiva da doença. A melhora na condição clínica associada ao tratamento com EGS parece também estar associada à modulação de populações bacterianas no intestino com características supostamente colitogênicas (Pseudomonas monteilii) e protetoras (Ruminococus champanelensis e Turicibacter sanguinis). De fato, o transplante de microbiota de camundongos tratados com EGS para animais que sofreram indução da colite levou à aparente melhora do escore pós-morte e à redução de leucócitos circulantes. Além disso, o transplante diminuiu a expressão de RNAm das citocinas inflamatórias IFN-? e IL-1?, indicando que alterações na microbiota intestinal podem ser um dos mecanismos pelos quais o EGS modula a colite experimental. Finalmente, experimentos utilizando a cromatografia líquida de alta performance (HPLC) sugerem que uma fração (F3) do extrato bruto da saliva, pode ser a responsável pela melhora observada nos sinais clínicos da doença. De forma geral, o EGS e seus componentes parecem representar uma fonte importante de moléculas imunomoduladoras com potencial terapêutico no tratamento da inflamação intestinal induzida experimentalmente / Inflammatory Bowel Disease (IBD) is an inflammatory disorder characterized by an imbalance between inflammatory and regulatory immune responses at the gut mucosa. However, current therapies are not totally effective and a plenty of patients require repeated surgeries to control disease complications. So, it is clear that novel therapies are still needed to control IBD progression. Thereby, since saliva from bloodsucking arthropods is a rich source of pharmacologically bioactive molecules, the aim of this study was to evaluate the therapeutic activity of Aedes aegypti total (SGE) and fractionated saliva in the treatment of experimental colitis. For this purpose, C57BL/6 male mice were exposed to 3% dextran sulfate sodium (DSS) in drinking water. The results showed an improvement in clinical disease outcome and postmortem scores after SGE treatment, regardless the route of administration used (i.p. or i.v.). This amelioration was accompanied by the systemic reduction in peripheral blood lymphocytes, especially when the i.v route was used. Furthermore, a reduction in the inflammatory area together with a local diminishment of IFN- ?, TNF-?, IL-1? and IL-5 cytokines were observed in the colon of SGE-treated mice. Similarly, a reduction of the frequency of TCD4+ lymphocytes producing IFN-?, IL-17 and IL-4 was observed in spleen and mesenteric lymph nodes (MLN) of SGE-treated mice. A lower frequency of CD11b+ cells in spleen and CD49b+ in MLN was also observed after SGE treatment. Interestingly, early treatment with SGE led to mice protection from a late DSS rechallenging, indicating that the mosquito saliva may present components able to prevent disease relapse. Clinical improvement due to SGE therapy seems to be also related to the modulation of intestinal bacterial population with different characteristics. Thus, SGE-therapy managed to a diminishment of colitogenic (Pseudomonas monteilii) and improvement of protective (Ruminococus champanelensis e Turicibacter sanguinis) bacteria. In fact, microbiota transplantation from SGE-tretaed mice to mice exposed to DSS-colitis improved postmortem scores and induced systemic diminishment in peripheral blood lymphocytes. Additionally, a reduced mRNA levels for the inflammatory cytokines IFN-? and IL-1?, was observed in transplanted mice, pointing to the effects of SGE-therapy in the modulation of gut microbes as one of the mechanisms related to the improvement of disease outcome. Finally, high performance liquid chromatography (HPLC) experiments suggested a major SGE pool fraction (F3) able to ameliorate disease signs. In conclusion, SGE and its components might represent a source of important immunomodulatory molecules with promising therapeutic activity for experimentally induced intestinal inflammation.

Le risque d’accidents artériels aigus chez les patients atteints de maladie inflammatoire chronique intestinale (MICI) reste incertain. L’objectif de cette thèse est d’évaluer le risque d’accident artériel aigu chez les patients atteints de MICI et l’impact des traitements sur le risque à partir des bases de données médico administratives françaises PMSI et SNIIRAM. La prise en charge thérapeutique des patients atteints de MICI a été initialement étudiée afin de valider le code diagnostique dans les bases de données. L’exposition au traitement, les taux d’hospitalisation et de chirurgie sont similaires à ceux attendus et les taux d’incidence sont comparables à ceux rapportés dans d’autres populations. Les patients atteints de maladie de Crohn (MC) et rectocolite hémorragique (RCH) ont un surrisque d’accident artériel aigu comparé à la population générale. Le risque le plus élevé est observé chez les patients de moins de 55 ans. L’activité de la MICI est un facteur de risque indépendant d’accident artériel aigu, avec une magnitude d’effet similaire dans la MC et la RCH. Comparés aux patients non exposés, les patients exposés à la monothérapie thiopurines, anti-TNFs et combothérapie ont un risque moins élevé d’accident artériel aigu, mais cette différence est seulement significative chez les patients exposés à la combothérapie. La diminution du risque est la plus importante chez les hommes atteints de MC exposés à la combothérapie. La modulation du risque d’accident artériel aigu devrait être prise en compte dans la balance bénéfice-risque des traitements par thiopurines et anti-TNFs chez les patients atteints de MICI. / The risk of acute arterial events in inflammatory bowel disease (IBD) remains unclear. The objectives of this thesis are to assemble a nationwide cohort of IBD patients based on the French administrative health databases, in order to assess the risk of acute arterial events in IBD and the impact of immunosuppressive treatment on the risk. Disease course and therapeutic management of IBD were first studied, in order to validate the coding diagnosis of IBD in the databases. Treatment exposure, hospitalisation, and surgery rates are similar to current standard of care and incidence rates are in the range of those reported in other populations. Patients with Crohn’s disease (CD) and ulcerative colitis (UC) have an increased risk of acute arterial events compared with the general population. The highest risk is observed in patients under the age of 55 years. Disease activity is an independent risk factor of acute arterial events, with a similar magnitude of risk in CD and UC. Exposure to thiopurine and anti-TNF monotherapies, and combination therapy are all numerically associated with a decreased risk of acute arterial events compared to unexposed patients, although the difference is only statistically significant for patients exposed to combination therapy. The magnitude in risk reduction is highest in men with CD exposed to combination therapy. These studies support the concept that a tight control of inflammation is crucial in patients with IBD to avoid IBD-related systemic complications. Prevention of acute arterial events should be considered in the benefit-risk balance assessment of thiopurines and anti-TNFs treatment in IBD patients, according to age, sex and IBD subtype.

Bc. Klára Horáčková DIPLOMA THESIS Mechanisms of immune dysregulation leading to inflammatory bowel disease Abstract Inflammatory bowel disease (IBD) is a complex disorder characterized by chronic inflammation of the gastrointestinal tract. Classical IBD is a multifactorial disease with adulthood or later-childhood onset. However, children with very early onset IBD (VEO-IBD, before 6 years of age) are a specific cohort, whose pathology can be caused by severe genetic defects in genes connected to immune homeostasis in the gut. We aimed to identify the causal genetic variants in 20 pediatric patients diagnosed with IBD (age of onset from 3 to 154 months) using whole exome sequencing (WES). We evaluated several bioinformatical approaches for WES data analysis. This included a comparison of two methods of variant identification using VarScan2 or GATK4-based tools. Furthermore, we compared 4 gene lists ("virtual panels") for variant filtering, one of which was compiled purposefully for this thesis. We identified and validated via segregation analysis 5 causal variants in 4 genes (DUOX2 compound heterozygote, FOXP3, NLRP3 and NOD2) accounting for 20 % of the cohort. NOD2 (p.A755V) variant has already been reported in IBD cases, while DUOX2 (p.R1216W + p.A1131T), FOXP3 (p.H400L) and NLRP3 (p.V200M) were newly...

This diploma thesis is focused on patients who are undergoing surgery - intestinal resection. In a surgical patient, malnutrition is a frequent and significant negative factor that affects postoperative morbidity and lethality. Proper nutritional care has an irreplaceable role in the prevention and treatment of malnutrition. Nutritional elements are part of the perioperative care of the modern ERAS concept, which leads to reduction in the frequency of postoperative complications and a shortening of the hospitalization duration. The concept emphasizes early physical rehabilitation and shortening of the fasting period around the time of the operation, which leads to a significant saving of body protein. The theoretical part describes particular diseases that lead to surgical treatment. Special attention is paid to idiopathic intestinal inflammations and colorectal cancer. It also includes current recommendations of professional companies. The primary objective of the practical part is to compare two groups of patients who underwent intestinal resection. To find out whether targeted nutritional intervention (before, during and after surgery) has an impact on postoperative convalescence, the frequency of complications and the overall length of hospitalization. The aim was also to improve the quality of...

Background: Inflammatory Bowel Disease (IBD) is a chronic, relapsing, autoimmune disease, affecting one in every 150 Canadians. Failure to induce remission of IBD with pharmacotherapy can necessitate surgical interventions, such as the creation of an ostomy. Ostomy surgery can help manage severe IBD and thus improve quality of life; however, individuals living with IBD report the possibility of ostomy surgery as a top concern, which can lead them to refuse or delay this decision until the disease becomes life threatening. Research Objective: The aim of this study is to understand what factors influence the decision to have ostomy surgery in young women with IBD, how the perception of the surgery compares to the reality of living with an ostomy, and the role healthcare professionals play in this decision. Methods: Nine participants who (1) identify as female, (2) are between the ages of 19 and 30, and (3) are currently living with an ostomy to treat IBD were recruited for this study. Additionally, seven healthcare professionals who work with IBD patients were recruited. Participants were invited for an individual, semi-structured interview. Findings: Young adult women living with an ostomy to treat their IBD reflected on their initial fears and concerns about undergoing surgery. Due to the severity of their illness, the majority of participants had requested surgery after having some time to adjust to the idea. This request, however, was often met with resistance or obstacles in the healthcare system. Healthcare professionals share mixed perceptions of ostomy surgery, with some viewing it as a last resort and others perceiving it as a treatment option. Once surgery had been performed, young adult women describe some challenges adjusting to life with an ostomy; but the majority report experiencing an overall improvement in quality of life. Conclusion: Understanding the perceptions that influence how young women perceive ostomies prior to versus after surgery will help identify the factors that influence the decision-making process for ostomy surgery, such as gender, age and stigma. Challenging current beliefs and assumptions may allow more supportive conversations between healthcare professionals and patients and provide insight on the actual lived experience of young women living with an ostomy. / Graduate / 2023-01-13

Bakgrund: Inflammatorisk tarmsjukdom (IBD) inkluderar Ulcerös kolit och Crohns sjukdom som kännetecknas av återkommande inflammation i tarmen. Etiologin för sjukdomarna är fortfarande okänd och forskning visar en ökning, framför allt i Europa. För att främja hälsa trots en livslång sjukdom behöver individen ta ansvar för att anpassa sin sjukdom genom egenvård, detta för att förebygga exacerbation. Syfte: Syftet med studien var att sammanställa personers upplevelser av att anpassa sitt liv utifrån sin kroniska inflammatoriska tarmsjukdom.  Metod: En beskrivande litteraturstudie baserat på 12 kvalitativa studier. Databaserna som användes vid artikelsökningarna var PubMed och CINAHL. Sökbegränsningarna var engelska, människor och 10 år.  Resultat: En återkommande upplevelse bland personerna med IBD var att livet blev begränsat både gällde skola- och arbetsliv, det sociala livet och kosten. För att anpassa sitt liv med en IBD-sjukdom upplevde personerna att kunskap och stöd från andra var betydande. För att hålla sjukdomen i remission upplevdes behandlingar och kostanpassningar vara en viktig fördel. Upplevelsen av sig själv förändrades där en känsla av att inte vara normal var vanligt, att acceptera och hitta mening i livet var en viktig anpassning och resulterade i ett bättre mentalt välbefinnande. Slutsats: Sjukdomen upplevdes skapa begränsningar i det dagliga livet och ändrade självbilden hos personerna. Att acceptera sitt liv med IBD ansågs vara en viktig anpassning för att skapa möjlighet till att leva sitt liv utan dessa upplevda begränsningar. Enligt författarna kommer resultatet ge sjuksköterskor en ökad förståelse gällande omvårdnaden för personer med en IBD-sjukdom samt möjliggöra en fungerande egenvård för dessa personer. / Background: Inflammatory bowel disease (IBD) include Ulcerative Colitis and Crohn’s disease who are characterized by recurrent inflammation in the bowel. The etiology of the diseases is still unknown, and research shows that it’s increasing, especially in Europe. To promote health despite a lifelong illness, the individual needs to take responsibility for their self-care to keep the disease in check. Aim: The aim of this study was to describe persons experience of adapting their life with their inflammatory bowel disease. Method: A descriptive literature study based on 12 qualitative studies. The databases used were PubMed and CINAHL. The study's limitations were English, humans, and 10 years.  Results: A recurring experience among people with IBD was that life was limited in school, work, social life and diet. Knowledge and support from others were important to adapt to a life with IBD. To keep the disease in remission, treatments and dietary adjustments were perceived as an important advantage. The experience of yourself changed, where a feeling of not being normal was common. Patients who were able to accept their disease, and who also transcended to find a higher purpose, ultimately improved their mental health.   Conclusion: The disease creates limitations in daily life and changes the self-image of people. Accepting a life with IBD was an important adjustment to create the opportunity to live one's life without these perceived limitations. According to the authors, the results will give nurses an increased understanding of caregiving and improved self-care for people with IBD.

Cancer treatments including chemotherapy and radiotherapy treat cancer by targeting rapidly dividing cells. Although these forms of treatment damage rapidly dividing cancer cells, they are also toxic to the cells of the gastrointestinal tract, leading to inflammation of the mucosal layer (mucositis) and causing nausea, vomiting, diarrhea, and abdominal pain. Improvement in symptoms may allow patients to have better performance status permitting ongoing treatment and possibly a better prognosis. This article describes the pathophysiology of chemotherapy-induced mucositis and includes 3 case reports of treatment of mucositis with serum bovine immunoglobulin.