As doenças falciformes (DF) constituem um grupo de doenças hereditárias monogênicas. São doenças extremamente relevantes no contexto de saúde pública no Brasil, portanto diferentes estratégias terapêuticas devem ser avaliadas. As oclusões vasculares afetam praticamente todos os órgãos, inclusive o baço e a medula óssea, porém não existem dados na literatura se estas comprometem também o tecido tímico. Os pacientes apresentam maior suscetibilidade às infecções cujas causas não são ainda totalmente esclarecidas Embora as infecções observadas nos pacientes sejam atribuídas à disfunção esplênica, o quadro inflamatório crônico e possíveis alterações no timo e na medula óssea, também poderiam causar uma disfunção imunológica. O objetivo deste trabalho foi avaliar a neogênese de células T e B e a diversidade do repertório de células T periféricas em pacientes com anemia falciforme (AF) sem tratamento (N = 15), tratados com hidroxiuréia (N = 20) ou transfusão crônica (N = 21) e em pacientes com DF tratados com transplante de células-tronco hematopoéticas (TCTH) alogênico (N = 29). Pacientes sem tratamento apresentaram menores níveis de sjTREC e ?-TREC, e menor taxa de divisão celular intratímica, demonstrando alterações importantes na neogênese das células T. A produção tímica de novas células T naïve foi reestabelecida em um ano pós-transplante, com normalização dos níveis de sjTREC e ?-TREC. O desenvolvimento de doença do enxerto contra o hospedeiro (DECHa) e reativação de citomegalovírus comprometeu a timopoiese nos primeiros seis meses pós-transplante, com diminuição significativa dos níveis de sjTRECs e ?-TRECs. Análises do repertório da cadeia V? dos receptores de células T (TCRs), pelo método TCRBV CDR3 spectratyping, indicaram que os pacientes com AF apresentaram um repertório menos diverso, composto predominantemente de famílias V? com padrão skewed e picos de CDR3 monoclonais, sendo a família V?3 mais frequente. A composição do repertório de células T foi alterada após o transplante, adquirindo um perfil mais policlonal dos picos de CDR3 ao longo do tempo. A família V?22 foi a mais expressa no período pré-transplante e em todos os seguimentos pós-transplante. Os pacientes com DF apresentaram aumento de linfócitos B naive, demonstrado pelos altos níveis de sjKRECs e pela taxa de proliferação homeostática. As análises multivariadas demonstraram que as alterações esplênicas influenciam diretamente os níveis de sjKREC, indicando que a baixa função esplênica leva ao aumento da produção de células B naive pela medula óssea, sugerindo um mecanismo compensatório. Os resultados desse trabalho demonstraram a existência de um desequilíbrio na neogênese de células T e B e consequentemente nesses compartimentos celulares periféricos, que pode conferir aos pacientes com DF uma maior susceptibilidade a infecções. Entre as diferentes modalidades terapêuticas, o TCTH alogênico sobressaiu-se em relação aos tratamentos convencionais, melhorando a neogênese de células T e B a longo prazo. / Sickle Cell Disease (SCD) are a group of monogenic hereditary diseases. These are extremely relevant diseases in the context of public health in Brazil, thus, different therapeutic strategies must be studied. Vascular occlusions affect practically all organs, including the spleen and bone marrow. However, there are no literature data about the impact of vaso-occlusions on the thymic tissue. Patients are more susceptible to infections whose causes are not fully elucidated. Although the infections observed in these patients are assigned to splenic dysfunction, the chronic inflammatory state and possible alterations of the thymus and bone marrow could also lead to immune dysfunction. The goal of this work was to evaluate the neogenesis of T and B cells and the diversity of peripheral T cell repertoire in patients with sickle cell anemia (SCA) without treatment (N = 15), treated with hydroxyurea (N = 20) or chronic transfusions (N = 21) and in patients with SCD treated with hematopoietic stem cell transplantation (N = 29) allogeneic. Patients without treatment had lower levels of sjTREC and ?-TREC, and lower rate of intrathymic cell division, demonstrating important alterations in the neogenesis of T cells. The thymic production of new naïve T cells was reestablished at one-year post transplantation, with normalization of sjTREC and ?-TREC levels. The development of graft-versus-host disease (aGVHD) and cytomegalovirus activation compromised thymopoiesis in the first six months post transplantation, with a significant decrease of sjTRECs and ?-TRECs levels. Analysis of the TCR V? chain repertoire by TCRBV CDR3 spectratyping indicate that patients with SCA showed a less diverse repertoire, mainly composed by V? families with a skewed pattern and monoclonal CDR3 peaks, being the V?3 family the most frequent one. The composition of the T-cell repertoire was altered after transplantation, changing over time to more polyclonal profile of the CDR3 peaks. The V?22 family was the more expressed at pre-transplantation and at all follow-up periods. Patients with SCD presented increased numbers of naive B cells, demonstrated by higher levels of sjKRECs and homeostatic proliferation. Multivariate analysis demonstrated that splenic function directly influenced sjKREC levels, indicating that compromised splenic function leads to increase of naive B cell output by the bone marrow, suggesting a compensatory mechanism. The results of this study showed the existence of an imbalanced T and B cell neogenesis and, consequently on these peripheral cell compartments, which may confer to patients with SCD an increased susceptibility to infections. Among different therapeutic modalities, allogeneic HSCT stood out in relation to the conventional treatments, improving long-term T and B cell neogenesis.

Introdução: A Imunodeficiência Comum Variável (ICV) faz parte de um grupo de imunodeficiências primárias na qual os pacientes apresentam defeitos na maturação e diferenciação dos linfócitos B (LB), resultando em distúrbios funcionais além de alterações na distribuição de seus subtipos. Consequentemente, estes pacientes apresentam hipogamaglobulinemia, susceptibilidade a infecções e ausência de produção de anticorpos a antígenos específicos. Na tentativa de reduzir os episódios de infecções recorrentes, alguns trabalhos têm recomendado a vacinação com patógenos mortos ou subunidades e em trabalho anterior demonstramos a eficácia clínica da vacinação de pacientes com ICV, porém, a experiência com a administração de vacinas em imunocomprometidos é limitada. Objetivos: Avaliar a cinética da distribuição das subpopulações de linfócitos B antes e após a vacinação com antígenos proteicos e polissacarídicos em pacientes com ICV acompanhados no Ambulatório de Imunodeficiências Primárias do Hospital das Clínicas, FMUSP, além da produção de anticorpos específicos aos antígenos vacinais. Pacientes e Métodos: Um grupo de 35 pacientes com ICV e 16 controles foram vacinados contra Influenza, H1N1 e S. pneumoniae. Após as coletas nos tempos pré e pós 1, 3 e 6 meses foram realizados a separação de PBMC e cultura de linfócitos com lisado viral e hemaglutinina de Influenza, além da citometria de fluxo para identificação das subpopulações de LB naive, zona marginal (MZB), memória com troca de isotipo (SMB) e plasmoblastos (PBL). Foram dosados os anticorpos específicos e no grupo dos pacientes foi aplicado um score de sintomas antes e após a imunização. Resultados: Apesar da redução significativa na pontuação do score de sintomas, a maioria dos pacientes não produziu anticorpos específicos para Influenza, H1N1 e S. pneumoniae. A análise da cinética das subpopulações de LB revelou que em indivíduos saudáveis, a resposta contra Influenza apresentou duração de 6 meses, observada por meio da redução da subpopulação naive e aumento gradual da frequência de SMB a partir do primeiro mês. Observamos também redução da população de memória por volta do 3º mês, com aumento da população de PBL que permaneceu elevada até o 6º mês. Por outro lado, a despeito de os pacientes apresentarem aumento de SMB no primeiro mês após a vacinação, sua frequência foi inferior ao observado nos controles, decaindo ao terceiro mês. A população de PBL apresentou aumento precoce no primeiro mês após a vacinação, também muito menor do que observado nos controles, não sendo mantido no terceiro mês. Ainda, observamos uma correlação entre o aumento da expressão destas duas subpopulações no primeiro mês. Apenas a população de MZB apresentou aumento significativo no terceiro mês nos pacientes quando comparados aos controles. Ao dividirmos os pacientes de acordo com a expressão de SMB e PBL após 1 mês da administração das vacinas, observamos que os pacientes que apresentaram aumento na expressão de células B de memória foram os que exibiram uma melhora clínica mais expressiva, soroconverteram e desenvolveram soroproteção para H1N1.Conclusões: Apesar de não apresentarem eficaz diferenciação em células de memória e efetoras, resultando na resposta precoce e de curta duração, observamos que os pacientes foram capazes de reconhecer e responder às vacinas. Além disso, a elevada expressão de MZB no terceiro mês após a vacinação pode sugerir a atuação desta subpopulação na apresentação para os LT. Estes achados reforçam a necessidade de uma melhor compreensão da ativação do sistema imune em pacientes com ICV, para uma adequada subdivisão de acordo com o perfil de resposta após a vacinação / Introduction: Common Variable Immunodeficiency (CVID) is a primary antibody deficiency characterized by defects in B lymphocyte maturation, resulting in disturbed differentiation, distribution and functional variations on its subtypes. As a result , CVID patients have hypogammaglobulinemia and poor antibody response to specific antigens with increased susceptibility to infections. In an effort to minimize the recurrent episodes of infections, some studies have recommended immunization with inactivated pathogens or subunits and in a former study we have shown the clinical improvement determined by immunization in CVID patients, but the experience with vaccines\' administration to immunodeficient patients is limited. Objectives: To evaluate the changes in distribution of B cell subtypes before and after vaccination of CVID patients followed at the Division of Clinical Immunology and Allergy of University of São Paulo Medical School with protein and polysaccharide antigens, as well as specific antibody production . Methods: A group of 35 CVID patients and 16 controls were vaccinated against Influenza, H1N1 and S. pneumoniae vaccines. Blood samples were collected before and 1, 3 and 6 months post vaccination. PBMCs were stimulated with Influenza viral lysate and hemagglutinin peptide. Flow cytometry was performed to identify naïve B cells, marginal zone (MZB), switched memory B cells (SMB) and plasmablasts (PBL). Specific antibody production was measured and a symptoms score was applied for clinical evaluation before and after immunization. Results: In spite of the significant reduction in symptoms score after vaccination, most patients didn\'t produce specific antibodies to Influenza, H1N1 and S. pneumoniae. The analyzes of B cell subtypes changes in healthy individuals upon in vitro Influenza stimulation showed that the response endured up to 6 months post immunization. We observed a reduction in naïve B cell frequency while gradual increase in SMB frequency occurred already at 1 month after vaccination. Moreover, as the memory cell population declined, PBL population increased at the third month post vaccination until the sixth month. Although patients had an increase of SMB on the first month after vaccination, it was lower than that observed in controls, decreasing by the third month post vaccination. Plasmablast frequency had an early increase on the first month, also much lower than the observed in controls decreasing by the third month. In addition, we observed a correlation between the increased expression of SMB and PBL on the first month post vaccination. In patients, only MZB subtype presented a significant increase on the third month when compared to controls. We divided the patients according SMB and PBL expression after 1 month post vaccination and we observed that patients who were able to produce memory B cells showed a better clinical improvement, developed H1N1 seroconversion and seroprotection. Conclusion: Despite the defect on differentiation into memory and effector B cells resulting in early response with lowduration, we observed that patients were able to recognize and respond to vaccines. In addition, the over expression of MZB on the third month after vaccination may suggest the role of this subpopulation as an antigen presenting cell for T cells. These findings reinforce the need of a better understanding of immune system activation and response in CVID patients to propose a division according to vaccine (antigen) responders and non responders

L’outil génomique a considérablement modifié notre connaissance des hémopathies malignes, que ce soit sur le plan physiopathologique, diagnostique, pronostique ou thérapeutique. Dans la première partie de ce travail, nous avons travaillé sur une grande cohorte d’anémies réfractaires sidéroblastiques avec thrombocytose (ARS-T). Nous avons démontré qu’il s’agissait d’une entité indépendante, avec une présentation moléculaire particulière associant (i) des mutations de SF3B1 dans plus de 85% des cas, expliquant son versant myélodysplasique et (ii) des anomalies de JAK2 dans plus de 50% des cas, expliquant son versant prolifératif. La perspective de cette première partie est d’identifier la ou les mutation(s) responsables du caractère myéloprolifératif dans les ARS-T JAK2WT. Les lymphomes B-diffus à grandes cellules (LBDGC) représentent les lymphomes malins non-Hodgkiniens les plus fréquents chez l’adulte. Dans la deuxième partie de ce travail, nous avons réalisé l’analyse par SNP-array d’une série homogène d’échantillons issus de la cohorte CORAL, une étude prospective internationale portant sur les LBDGC en rechute. Notre objectif était d’identifier les anomalies de nombre de copies (ANC) associées à chacun des deux types de rechutes, précoces ou tardives. Les rechutes précoces sont associées à une forte proportion d’anomalies affectant les régulateurs du cycle cellulaire, de l’apoptose et de la transcription. Les rechutes tardives sont associées à des anomalies affectant les régulateurs de l’immunité et de la prolifération cellulaire. Cette étude permet de mieux comprendre les déterminants de la rechute dans les LBDGC et ouvre de nouvelles perspectives thérapeutiques / Genomics provided new insights in our knowledge of pathophysiology, diagnostic approach, prognosis and therapeutic perspectives in hematological malignancies. In the first part of this work, we studied a large cohort of Refractory Anemia with Ring sideroblasts and marked Thrombocytosis (RARS-T). We demonstrated that RARS-T can be considered as an independent entity, with a specific molecular pattern, associating : (i) SF3B1 mutations in more than 85% of cases, accounting for its myelodysplastic aspect and (ii) JAK2 mutations, accounting for its myeloproliferative aspect in more than 50% of cases. Future prospects of the first part of this work is to identify (the) mutation(s) responsible for the myeloproliferative part of JAK2WT RARS-T. Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma in adults. In the second part of this work, we performed SNP-array analysis of a homogeneous series of samples from the CORAL cohort, an international prognostic study on relapsed DLBCLs. Our purpose was to identify Copy Number Variations (CNV) associated ER or LR. ER DLBCLs are associated with high rates of CNVs affecting regulators of cell cycle, apoptosis and transcription. In LR DLBCLs, CNVs are related to immune response and cell proliferation. This study provides new insights into the genetic aberrations in relapsed DLBCLs and open up new therapeutic perspectives

A exposição limitada ao Plasmodium chabaudi induz proeminente imunidade celular, associada à proteção de células T da apoptose. Este estudo tem como objetivo verificar a influência da carga parasitária na geração e manutenção dos linfócitos T e B de memória ao P. chabaudi. Assim, camundongos C57BL/6 foram submetidos à infecção tratada (subpatente) ou não (patente) com cloroquina após a inoculação de 106 eritrócitos parasitados (EP) e analisados nos dias 0, 20, 60, 120 e 200. Com relação à memória de linfócitos T, no dia 20, as freqüências de células CD4+ memória/ativadas e respondedoras aos EP foram significativamente maiores nos animais do grupo subpatente. Os níveis máximos de IgG2a específica foram encontrados no dia 120 em ambos os grupos. O desafio dos animais com 108 EP mostrou que a imunidade protetora declina progressivamente, mas os grupos ainda são capazes de estabelecer resposta secundária eficiente que elimine o parasita. Assim, podemos concluir que a carga parasitária influencia a fase aguda, mas não impede a geração e manutenção das células T e B de memória. / One of the main characteristics of malaria is the intense policlonal activation of splenic T and B lymphocytes induced by the parasite and the consequent elimination, through apoptosis, of part of these cells. However, the limited exposure to the bloodstage malaria seems to induce a prominent cellular immunity, associated with the protection of T lymphocytes from apoptosis. With this in mind, this study aimed to verify the influence of the parasite load in the generation and maintenance of memory T and B cells specific for Plasmodium chabaudi chabaudi AS. In order to evaluate this idea, C57BL/6 mice were infected with 106 parasitized red blood cells (pRBC) and submitted to a patent (untreated) or subpatent infection (controlled with sub-curative doses of chloroquine every time parasitemia reached 1%). Splenocytes from these mice were analyzed at 20, 60, 120 and 200 days after infection, regarding the pRBC-specific T cell proliferation and the expression of surface molecules, as CD4, CD8, CD62L, CD45RB, CD44, CD45R-B220 and IgG. The parasitemia and the splenocyte phenotype were also monitored after the challenge with 108 pRBC. Regarding T cell memory, at day 20 of infection, the frequencies of effector/activated CD4+ T cells (CD62LLOW CD45RBLOW/HIGH) were significantly increased in animals from the patent group, which was strict linked with the highest cellular activation observed in these animals. On the other hand, the total numbers of pRBCproliferating T (CD4+ and CD8+) cells per spleen were approximately 3-fold increased in subpatent animals, indicating that these cells were protected from apoptosis as a result of the limited exposure to the parasite. However, in both groups, these parameters decreased to values similar to those in controls at day 200. The splenocytes from both groups produced Th1 cytokines in response to pRBC in all times of analysis, but at the early phase of infection, Th2 cytokines were also observed, but without differences between the infected groups. Regarding memory B cells, the frequency of sIgG+ cells was increased at day 20 of infection, when 11% and 9% of CD45R+ cells from patent and subpatent animals were positive, respectively. For both groups, specific IgG2a antibodies attained maximum serum levels at day 120, but at day 200, it is possible to observe a significant decrease of these levels only in the serum of patent mice. Moreover, at day 200 of infection, mice of subpatent group showed significantly higher amounts of IgG2a that recognized the intra-erythrocytic forms of the parasite and the surface of infected erythrocytes. Challenge of mice with 108 pRBC showed that protective immunity progressively decline with time and despite the higher levels of specific antibody in subpatent mice, both groups showed similar protection. In experiments of adoptive transference to CD28-/- mice, cells from 200-day infected mice were able to produce specific IgG2a antibodies, in a T CD4+ cell dependent way. In addition, we verified that CD45R+ cells of subpatent mice, when transferred to CD28-/- mice, secreted higher amounts of specific IgG2a and IgG1 antibodies, comparing to cells of patent mice. So, from this work, we can conclude that the parasite load has a great influence in the early immune response to P. chabaudi malaria and it also affects the generation and/or maintenance of memory B cells. Furthermore, according to our data, at least during the analyzed period, the loss of protective immunity against this parasite does not seem to be influenced by the acute-phase parasite load, but it can be a consequence of the progressive decline of T-cell memory response that occurs in patent and subpatent groups with time of infection.

Estudo dos processos linfoproliferativos cutâneos de células B objetivando demonstrar a difícil distinção diagnóstica entre os linfomas cutâneos e pseudolinfomas. Foram avaliados 38 casos de processos linfoproliferativos cutâneos de células B. Foi realizada revisão de prontuários médicos e exames anátomo-patológicos. Foram estudados 25 casos de linfomas cutâneos, 7 de pseudolinfomas e 6 casos onde não foi possível a distinção diagnóstica entre as entidades em estudo. As características clínicas, histológicas e imunoistoquímicas foram descritas para cada grupo. A análise estatística foi realizada demonstrando a similaridade entre os linfomas cutâneos e os pseudolinfomas / Study of cutaneous B-cell lymphoproliferative process with the purpose of demonstrating the difficulty of distinguishing between cutaneous lymphomas and pseudolymphomas. 38 cases of cutaneous B-cell lymphoproliferative processes were evaluated. A review of medical records and histophatologic material was performed. The study comprised 25 cases of cutaneous lymphomas, 7 cases of pseudolymphomas and 6 cases where a diagnosis distinguishing between the entities in study was not possible. It described clinical, histophatologic and immunohistochemical characteristics of each group. A statistical analysis showing the similarity between lymphomas and pseudolymphomas was performed

L'étude de la survie nette des patients atteints de cancer en population générale permet d'apprécier l'efficience globale du système de soin d'un pays. La survie nette se définit comme la survie qui serait observée si la seule cause de décès possible était le cancer. Ce concept est fondamental dans les comparaisons entre zones géographiques et/ou périodes de diagnostic dont l'intérêt est d'estimer les variations spécifiques de la mortalité due au cancer. Le concept de survie nette permet de prendre en compte les éventuelles différences de mortalité naturelle entre les groupes comparés. Actuellement, seuls deux outils estiment la survie nette sans biais : l'estimateur non paramétrique de Pohar-Perme et la modélisation paramétrique ajustée sur certaines covariables (essentiellement l'âge). Par ailleurs, les outils paramétriques s'étant perfectionnés, de nouveaux modèles flexibles permettent de modéliser les effets complexes des variables sur la mortalité. Ce travail repose sur la modélisation du taux de mortalité en excès à la suite d'un lymphome malin non hodgkinien, en se basant sur le modèle proposé par Remontet et al. et sur la nécessité de modéliser conjointement les effets complexes des covariables (telles que le temps de suivi, l'année de diagnostic et l'âge) sur la mortalité à l'aide d'une stratégie de modélisation adaptée. L'effet des variables est restitué sur la survie nette mais aussi sur le taux de mortalité en excès ce qui représente un élément nouveau dans les études de survie. Deux applications ont été menées sur des bases de données collaboratives de population : d'une part sur les données françaises du réseau FRANCIM à la suite d'un diagnostic de lymphome folliculaire entre 1995 et 2010 et, d'autre part, sur les données européennes d'EUROCARE-5 après un lymphome folliculaire ou un lymphome B diffus à grandes cellules diagnostiqué entre 1996 et 2004. Les résultats montrent que la dynamique du taux de mortalité en excès au cours du temps de suivi varie en fonction du sous-type de lymphome, de l'âge et de la zone géographique. Les tendances de cette dynamique en fonction de l'année de diagnostic sont également différentes / The net survival of cancer patients in population studies is the most relevant indicator to assess the overall efficiency of the healthcare system of a country. Net survival is defined as the survival that would be observed if the sole cause of death were cancer. This concept is crucial in comparative studies (between geographical areas and/or periods of diagnosis) that estimate specific variations of cancer-related deaths. Net survival takes into account potential differences in mortality patterns between groups. Currently, two methods provide unbiased estimations of net survival: the non-parametric estimator of Pohar-Perme and the parametric model adjusted on specific covariates (mainly, the age at diagnosis). Moreover, new improved parametric tools, such as flexible models, can model the complex covariate effects on mortality. In this work, we modeled the excess mortality rate after a non Hodgkin lymphoma diagnosis, with a model developed by Remontet et al. In addition, we used an appropriate model-building-strategy to model jointly the complex effects of some covariates (such as the time elapsed since diagnosis, the year of diagnosis, and age) on the excess mortality. Finally, this approach allowed for the covariate effects on the net survival and on the excess mortality rate. We applied this method to two different collaborative databases: first on the French database FRANCIM (1995 to 2010) to study the excess mortality after diagnosis of follicular lymphoma, then on the European data of EUROCARE-5 (1996 to 2004) to study the excess mortality after diagnosis of follicular lymphoma and diffuse large B-cell lymphoma. According to the results, the dynamics of the excess mortality rate varies over the time elapsed since diagnosis according to the lymphoma subtype, the age, and the geographical area. The trends of these dynamics over the years of diagnosis are different too

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Para avaliar a influência dos polimorfismos de nucleotídeo único (SNPs) do CYP2B6, CYP3A5, GSTM1, GSTP1, GSTT1, PON1, NQO1 e MDR1 na resposta ao tratamento com R-CHOP e CHOP, 82 pacientes com Linfoma Difuso de Grandes Células B, sem evidências de infecção por HIV, foram selecionados nesse estudo. Amostras de sangue periférico foram coletadas para extração de DNA. Os SNPs foram analisados por PCR-RFLP. Em relação aos pacientes que apresentaram resposta completa (RC) ao tratamento (70%), 51% foram tratados com R-CHOP. Sobre o tratamento, 50% dos pacientes com RC apresentaram classificação de ECOG 0-1 (p=0,0193) e a maioria desses pacientes (41%) não apresentaram envolvimento extranodal (p=0,0377). Não houve associação entre os SNPs do CYP2B6, CYP3A5, GSTT1, NQO1 e MDR1 (C3435T) e as variáveis estudadas. Apenas CYP3A5 (sexo p=0,0519), GSTM1 (idade p=0,016; tratamento p=0,0372), GSTP1 (envolvimento extranodal p=0,0307), PON1 (sintomas B p=0,0201; Bulky p=0,0148) e MDR1 C1236T (sexo p=0,0316) mostraram associação. Em relação à sobrevida global, apenas tratamento (p=0,0129), IPI (p=0,000342), idade (p=0,0155), estadiamento (p=0,00281) e ECOG (p=0,00869) apresentaram resultados significantes. Quanto à sobrevida livre de doença (SLD), apenas idade (p=0,0292), estadiamento (p=0,0402) e ECOG (p=0,0142) apresentaram resultados significantes / To evaluated the influence of single nucleotide polymorphisms (SNPs) of CYP2B6, CYP3A5, GSTM1, GSTP1, GSTT1, PON1, NQO1 and MDR1 in the treatment response with R-CHOP and CHOP, 82 patients with Diffuse Large B-cell Lymphoma, without evidence of HIV infection, were enrolled in this study. Peripheral blood samples were collected for DNA extraction. The SNPs were analyzed by PCR-RFLP. In relation the patients that showed complete response (CR) to the treatment (70%), 51% were treated with R-CHOP. About the treatment, 50% of the patients with CR showed ECOG classification of 0-1 and the most of these patients (41%) did not showed extranodal involvement (p=0,0377). There was no association between CYP2B6, CYP3A5, GSTT1, NQO1 and MDR1 (C3435T) SNPs and the variables studied. Only CYP3A5 (gender p=0,0519), GSTM1 (age p=0,016; treatment p=0,0372), GSTP1 (extranodal involvement p=0,0307), PON1 (B symptoms p=0,0201; Bulky p=0,0148) e MDR1 C1236T (gender p=0,0316) showed association. In relation to overall survival, only treatment (p=0,0129), IPI (p=0,000342), age (p=0,0155), stadiament (p=0,00281) and ECOG (p=0,00869) showed significant results. To disease-free survival, only age (p=0,0292), stadiament (p=0,0402) e ECOG (p=0,0142) showed significant results

Chez l’adulte les premières étapes du développement hématopoïétique se déroulent dans la moelle osseuse (MO). La contribution de cellules d’origine mésenchymateuse, appelées niches stromales, a été démontrée dans le cas de la maintenance des cellules souches hématopoïétiques (CSH) et du développement des lymphocytes B (LB). Ainsi la maintenance des CSH dépend de niches périvasculaires sécrétant CXCL12 et SCF. Par ailleurs les LB les plus précoces (preproB) sont en contact de cellules stromales CXCL12+, puis migrent vers des cellules stromales exprimant l’interleukine-7 lors de leur différentiation en cellules proB. L’expression du préBCR, marque ensuite l’entrée dans le stade préB. À ce stade, les cellules sont au contact de cellules stromales galectine-1+.Malgré les progrès obtenus dans la compréhension du rôle des niches stromales, leur hétérogénéité et les mécanismes contrôlant la migration et l’adhésion des cellules hématopoïétiques en différenciation restent à mieux définir. Dans cet objectif, nous avons caractérisé phénotypiquement les cellules stromales de la MO mais aussi démontré l’existence d’une niche multi-spécifique, associée aux sinusoïdes et capable de soutenir les CSH et les LB.La contribution des niches dans le développement et la résistance aux traitements des Leucémies Aigues Lymphoblastiques de type B (LAL-B), équivalents pathologiques des LB en développement, a aussi été démontrée. Au cours de mon travail de thèse nous avons révélé l'influence d'un facteur exprimé par des cellules stromales de la MO sur la prolifération des LAL-B. À terme, ces travaux permettront de développer des traitements ciblant les fonctions protectrices des niches tumorales. / In adults, the early stages of hematopoietic development take place in the bone marrow (BM). The contribution of specialized cells of mesenchymal origin, called stromal niches, has been demonstrated in the case of hematopoietic stem cell (HSC) maintenance and B lymphocyte development. Indeed, the maintenance of HSC depends on perivascular niches secreting CXCL12 and SCF. Furthermore progenitor B cells (preproB) are in contact with CXCL12+ stromal cells and migrate towards interleukin 7 expressing stromal cells during their differentiation into proB cells. PreBCR expression then marks the entrance into the preB cell stage. At this point, the cells are in contact with galectin-1+ stromal cells.Although progress have been made in understanding the role of stromal cell niches, their heterogeneity and the mechanisms controlling migration and adhesion of differentiating hematopoietic cells are controversial and remain to be defined. With this objective, we characterized phenotypically BM stromal cells but also demonstrated the existence of a multi-specific niche, associated to sinusoids and able to support both HSC and early B cells.The contribution of BM niches in the development and resistance to treatment of B cell Acute Lymphoblastic Leukemia (B-ALL), pathological equivalent of developing B cells has also been demonstrated. During my PhD, our work revealed the influence of a factor expressed by BM stromal cells on the proliferation of B-ALL. Ultimately, this work will allow the development of treatments targeting the protective functions of tumor niches.

<p>Patients with rheumatoid arthritis (RA) are at increased risk of developing malignant lymphoma, although details about this association remain unclear. The aims of this thesis were to investigate risk factors for lymphoma in patients with RA and to characterize these lymphomas regarding subtype, presence of Epstein-Barr virus (EBV), clinical manifestations and prognosis. </p><p>The Swedish hospital discharge register and the cancer register were used to identify RA patients with lymphoma. Two case-control studies were performed, one smaller including RA patients with lymphoma hospitalised in Uppsala health care region 1964-1983 (n=41) and one larger study of hospitalised RA patients with lymphoma in Sweden 1964-1995 (n=378). RA patients from the same cohorts, but without lymphoma, were matched as controls. Medical records for cases and controls were scrutinized for exposure information. The lymphoma tissues were reclassified according to the WHO classification, and presence of EBV was analysed by EBER in situ hybridisation.</p><p>The most important risk factor for lymphoma development was high RA disease activity. No association was determined between treatment with traditional disease modifying drugs, non-steroidal anti-inflammatory drugs, aspirin, peroral and intra-articular corticosteroids and lymphoma risk. Diffuse large B-cell lymphoma (DLBCL) was more frequent in RA patients than in lymphoma patients in the general population and displayed stronger association with RA disease activity than other lymphoma subtypes. RA patients with DLBCL had increased extranodal involvement and more advanced lymphoma stage at presentation than DLBCL patients in general, and the prognosis was poor. </p><p>A further subdivision of DLBCL into germinal centre (GC) and non-GC subtypes by the expression patterns of CD10, bcl-6 and IRF-4 showed a predominance of the non-GC subtype. This suggested peripheral activated B-cells as the cells of origin in these lymphomas. </p><p>The presence of EBV was low in lymphomas in RA patients (12%). </p>