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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Impact d’un gain de fonction de Cxcr4 sur le développement et la compartimentalisation périphérique des lymphocytes / Impact of a gain-of-Cxcr4-function in lymphocyte development and peripheral trafficking

Biajoux, Vincent 30 September 2013 (has links)
Le syndrome WHIM (SW) est un déficit immuno-hématologique rare causé principalement par des mutations autosomales dominantes du gène CXCR4 qui entrainent une troncation du domaine C-terminal (C-Ter) du récepteur. Les formes mutantes de CXCR4 associées au SW génèrent des altérations de la désensibilisation et de l’internalisation du récepteur en réponse à CXCL12, qui se traduisent par une hypersensibilité à l’action chimiotactique du ligand. CXCR4 est un récepteur de chimiokine exprimé sur les leucocytes dont le rôle dans l’hématopoïèse et le trafic leucocytaire à l’état basal suggère que la lympho-neutropénie des patients atteints du SW est due à des défauts de production et/ou de domiciliation périphérique des leucocytes causés par le gain de fonction de CXCR4. Néanmoins, la validation de cette hypothèse est difficile chez les patients. En générant une souche de souris (Cxcr4+/1013), porteuse d’une mutation rapportée chez une famille de patients par une stratégie de knock-in, nous avons mis en évidence le rôle du domaine C-Ter de Cxcr4 dans le développement, la domiciliation périphérique des lymphocytes et l’immunité adaptative à médiation humorale.Les principaux résultats issus de notre travail, obtenus en combinant des approches biochimiques, fonctionnelles, de reconstitution de l’hématopoïèse par compétition, de transferts adoptifs et d’injection d’anticorps anti-CD45 in vivo, sont : 1) La mutation Cxcr41013 tronquant le domaine C-Ter se comporte différemment en terme de signalisation, selon qu’elle soit présente à l’état hétérozygote ou homozygote, et perturbe respectivement les transitions double-négatif (DN) 2-DN3 et proB-preB de la lymphopoïèse dans le thymus et la moelle osseuse (MO). Au contraire, elle ne génère pas d’effets sur le développement des cellules NK et la myélopoïèse ; 2) La lymphopénie qui touche les lymphocytes B (LB) et T (LT) est un processus intrinsèque aux cellules porteuses de la mutation Cxcr41013 et suit un modèle allèle-dose-dépendant ; 3) Le défaut de désensibilisation de Cxcr41013 empêche le relargage des lymphocytes NK et B immatures de la MO et celui des LB et LT matures des ganglions lymphatiques dans le sang. A l’inverse, le gain de fonction exacerbe la migration des LB recirculants et LT matures et leur rétention dans le parenchyme médullaire ; et 4) malgré l’absence de follicules primaires dans les ganglions lymphatiques, les souris mutantes sont capables de mettre en place une réponse immunitaire humorale efficace et spécifique d’un antigène T-dépendant, comme en témoigne l’augmentation des LB du centre germinatif et des plasmocytes ayant effectué une commutation isotypique. En conclusion, nous démontrons que la signalisation fine médiée par Cxcr4 est nécessaire pour le développement, la compartimentalisation périphérique et la fonction des lymphocytes. / The WHIM Syndrome (WS) is a rare combined immuno-hematological disorder caused by inherited heterozygous autosomal dominant mutations in CXCR4, which result in most cases in the distal truncation of the receptor’s Carboxyl-terminal tail (C-Tail). Mutants of CXCR4 associated with WS display impaired desensitization and internalization of the receptor upon CXCL12 exposure, leading to enhanced migratory response. Because CXCR4 is expressed on leukocytes, we hypothesized that circulating pan-leukopenia could arise from altered CXCR4-mediated signalling that would skew tissue distribution and differentiation of leukocytes. This assumption was obviously difficult to address in patients. By generating a knock-in mouse strain (Cxcr4+/1013) that harbors a WS-linked gain-of-Cxcr4-function mutation, we establish that the C-tail domain in Cxcr4-mediated signalling is a pivotal regulator of lymphocyte development, peripheral trafficking and humoral immunity. The essential findings of our work, obtained by combining biochemical, bone marrow (BM)-mixed chimeras, in vivo labelling, adoptive co-transfers and functional approaches, are: 1) the C-tail truncating Cxcr41013 mutation caused differential signalling capacities depending on its heterozygous versus homozygous status and inhibited double-negative (DN) 2-to-DN3 and pro-B-to-pre-B developmental transitions during lymphopoiesis. In contrast, it had no effect on NK lymphopoiesis and granulopoiesis; 2) the resulting circulating B and T lymphopenia was due to hematopoietic cell-intrinsic defects and followed a mutated allele dose-dependent pattern; 3) impaired Cxcr41013 desensitization prevented the release of immature BM NK and B cells and mature lymph node (LN) B and T lymphocytes into the blood. Conversely, it forced homing and retention of mature recirculating B and T cells in the BM parenchyma; and 4) despite the absence of primary B-cell follicles in LNs, mutant mice produced efficient humoral responses upon immunization as illustrated by increased antigen-specific germinal center B cells and isotype-switched plasma cells. Collectively, our findings demonstrate that fine-tuning of Cxcr4 signal strength is required for optimal trafficking, egress and fitness of lymphocytes.
52

Modulation des activités du récepteur purinergique P2X7 au cours de l’activation des lymphocytes T / Modulation of purinergic receptor P2X7-dependant activities during T lymphocyte activation

Safya, Hanaa 08 December 2014 (has links)
L’ATP extracellulaire, à travers l’activation du récepteur P2X7, joue un rôle important dans l’immunité inné comme signal de danger responsable de l’assemblage de l’inflammasome, de la migration des cellules immunitaires et de la mort cellulaire. Bien que le rôle de la voie ATP/P2X7 dans l’immunité adaptative reste sous-estimé, il a été rapporté que le récepteur P2X7 participe aux mécanismes de signalisation impliqués dans l’activation des lymphocytes T, leur prolifération et leur différentiation. Notre laboratoire a récemment montré que les lymphocytes T effecteurs (CD4+ ou CD8+) en fin de réponse immunitaire secondaire, exprimant à la membrane la tyrosine phosphatase de membrane B220, sont totalement résistant à l’activation du récepteur P2X7 à cause d’une perte d’adressage de ce récepteur à la membrane. Le but de ce travail de thèse est d’étudier la sensibilité des lymphocytes T, à différents stades d’activation, aux activités cellulaires induites par l’ATP, notamment le clivage de la molécule de homing CD62L ou L-sélectine, l’ouverture du canal ionique, la formation du pore et l’externalisation de la PS. Mes principaux résultats montrent que les activités cellulaires dépendantes du récepteur P2X7 sont dissociées. Les lymphocytes T au stade effecteur/mémoire sont moins sensibles au clivage de la molécule CD62L que les lymphocytes T au stade naïf et récemment activé. Les lymphocytes naïfs T récemment activé en réponse immunitaire primaire sont les plus sensibles à la formation du pore. De plus, les lymphocytes T récemment activés, aussi bien en réponse immunitaire primaire que secondaire, sont les plus sensibles à l’externalisation de la PS. Enfin, dans les lymphocytes T récemment activé, les activités de pore et d’externalisation de PS, mais pas le clivage de CD62L, sont dépendantes du taux de calcium. / Extracellular ATP through the receptor P2X7 (P2X7R) plays a key role in innate immunity as a danger signal that causes the activation of the inflammasome, enhancement of immune cell migration and cell death. Although the role of the ATP/P2X7R pathway in adaptative immunity remains underestimated, it has been reported that P2X7R regulates signaling events involved in T-cell activation, proliferation, and differentiation into effector lineages. Moreover, we have previously shown that effector T lymphocytes (either CD4+ or CD8+) that express the B220 isoform of CD45 at the plasma membrane at the end of the secondary immune response are totally resistant to ATP stimulation due to loss of P2X7R membrane expression. In the present study, we compared the sensitivity of T lymphocytes to cellular activities trigerred by P2X7R according to their stage of activation. Interestingly, our results showed that P2X7-dependent cellular activities are dissociated. T lymphocytes at effector/memory stage are less sensitive to CD62L shedding than naïve or recently activated T lymphocyte during primary immune response. Naive T lymphocytes recently activated during primary immune response are the most sensitive to pore formation. Furthermore, recently activated T lymphocytes at both primary and secondary immune responses are the most sensitive to PS externalization. Finally, pore formation, PS externalization but not CD62L shedding, are dependent on calcium signaling.
53

Correlação entre a atipia linfocitária e o perfil imunológico de animais infectados pelo vírus da leucose enzoótica bovina / Correlation between immunological profile and atypical lymphocytes in bovine leukemia virus infected dairy cows

Tatiana de Rezende Spinola 09 September 2010 (has links)
Dentre as enfermidades que causam alterações hematológicas em bovinos podemos citar a leucose enzoótica bovina (LEB). Podendo em alguns animais, determinar formações tumorais por infiltração de células mononucleares (linfócitos, pró-linfócitos e linfócitos atípicos), em diferentes tecidos. A doença possui quadro sintomático pleomórfico e alterações hematológicas, evidenciadas por leucocitose e linfocitose persistente, com aumento de formas linfocitárias atípicas. Desta forma o presente estudo tem como objetivo avaliar a atipia linfocitária em bovinos da raça Holandesa Preto e Branco em animais soropositivos com ou sem a presença de linfocitose persistente e animais soronegativos para LEB e correlacioná-la com a apoptose de células CD5+ e a proliferação linfocitária. Assim, foram selecionados 56 animais, divididos de acordo com o leucograma e o sorodiagnóstico da LEB pela imunodifusão em ágar gel e pelo ensaio imunoenzimático em: negativos (n = 25), alinfocitóticos (AL, n= 12) e com linfocitose persistente (LP, n=19). Destes, 15 animais tiveram suas amostras sanguíneas avaliadas quanto a proliferação de linfócitos e apoptose. Os resultados deste estudo mostraram que, a contagem de leucócitos totais e os valores absolutos e relativos de linfócitos atípicos foram maiores no grupo LP. Em relação aos linfócitos atípicos, os linfócitos sombra de Gümprecht, linfócito monocitóide e linfócito com núcleo duplo, foram encontrados nos três grupos de estudo, porém mais comumente em animais infectados pelo VLEB, predominantemente no grupo manifestando linfocitose persistente. Este trabalho demonstrou uma menor proliferação de linfócitos nos animais infectados pelo VLEB manifestando LP, associado a uma menor apoptose de células CD5+. Na análise da correlação entre a apoptose de células CD5+ e a porcentagem das populações linfocitárias entre os 15 animais, observou-se que a apoptose tem uma correlação positiva com os linfócitos com núcleo duplo, o que não ocorreu nas demais populações celulares. Na correlação entre a proliferação, foi observado nos 15 animais, que quanto maior a porcentagem de linfócitos menor é a proliferação e quanto maior a porcentagem de linfócitos monocitóides menor a proliferação, o que não ocorreu nas demais populações celulares. Portanto, a manifestação da LP em animais naturalmente infectados pelo VLEB, pode ser associada ao aumento de linfócitos atípicos do tipo sombra de Gümprecht, linfócito monocitóide e linfócito núcleo duplo e da menor apoptose das células CD5 + e da menor proliferação de linfócitos / Among the diseases that cause hematological changes in cattle can cite the enzootic bovine leukemia (EBL). And in some animals, to determine tumor formations by infiltration of mononuclear cells (lymphocytes, pro-lymphocytes and atypical lymphocytes) in different tissues. The disease has symptoms very pleomorphic and hematological changes, evidenced by leukocytosis, and persistent lymphocytosis, an increase of atypical lymphocyte forms. Thus this study aims to evaluate the atypical lymphocyte in Holstein Black and White in seropositive animals with or without the presence of persistent lymphocytosis and animals seronegative LEB and correlate them with apoptosis of cells CD5 + and lymphocyte proliferation. Thus, we selected 56 animals, divided according to the WBC and serodiagnosis of LEB by agar gel immunodiffusion and by enzyme immunoassay in: negative (n = 25), non- lymphocytic (AL, n = 12) and with persistent lymphocytosis (PL, n = 19). Of these, 15 animals had their blood samples evaluated for lymphocyte proliferation and apoptosis. The results of this study showed that in total leukocytes and absolute and relative values of atypical lymphocytes were higher in group LP. Regarding atypical lymphocytes, lymphocytes Gumprecht shadow, lymphocyte and monocytoid lymphocytes with dual core, were found in the three study groups, but more commonly in animals infected VLEB, predominantly in the group with persistent lymphocytosis. This study demonstrated a reduced proliferation of lymphocytes in animals infected VLEB expressing LP, associated with lower apoptosis of CD5 + cells. In analyzing the correlation between apoptosis of cells and the percentage of CD5 + lymphocyte populations among the 15 animals, we observed that apoptosis has a positive correlation with lymphocytes with dual core, which did not occur in other cell populations. Correlation between proliferation, was observed in 15 animals, the higher the percentage of lymphocyte proliferation and lower the higher the percentage of monocytoid lymphocytes less proliferation, which did not occur in other cell populations. Therefore, the expression of LP in animals naturally infected VLEB may be associated with increased atypical lymphocytes of the type of shadow Gumprecht, lymphocyte and lymphocyte monocytoid dual-core and reduced apoptosis of CD5 + cells and reduced lymphocyte proliferation
54

EXPRESSION DE LA NEUROPILINE-1 DANS LES LYMPHOCYTES T CONVENTIONNELS ET « INVARIANT NATURAL KILLER T » (iNKT) MURINS

Milpied, Pierre 13 December 2010 (has links) (PDF)
La neuropiline-1 (Nrp-1) est une protéine transmembranaire agissant comme récepteur des sémaphorines de classe 3 (Sema3) et du facteur de croissance de l'endothélium vasculaire (VEGF). En plus de son rôle crucial dans le développement des systèmes nerveux et cardiovasculaires, Nrp-1 est impliquée dans des processus physiopathologiques impliquant certains de ses ligands classiques (Sema3 et VEGF) ou récemment caractérisés (TGF-β1 et PDGF) dans les tissus adultes. Dans le système immunitaire, Nrp-1 participe aux interactions entre les lymphocytes T et les cellules dendritiques, transmet les effets immunorégulateurs de Sema3A sur les lymphocytes T, et est impliqué dans le mécanisme suppresseur des lymphocytes T régulateurs (Treg) Foxp3+. Cependant, l'expression de Nrp-1 dans les lymphocytes T non-Treg humains et murins n'a été que peu étudiée. L'objectif de ce projet était de caractériser les populations de lymphocytes T Nrp-1+ non-Treg chez la souris, d'analyser leurs fonctions, d'identifier les mécanismes conduisant à l'expression de Nrp-1 dans ces cellules, et de comprendre le rôle joué par Nrp-1 dans les réponses immunitaires T. Mon travail s'est d'une part intéressé à une population de lymphocytes T non-conventionnels appelés lymphocytes « invariant natural killer T » (iNKT). Les lymphocytes iNKT sont des lymphocytes Tαβ dérivés du thymus aux propriétés immunomodulatrices reposant sur la sécrétion rapide de cytokines TH1 et TH2 après engagement de leur TCR semi-invariant par des complexes CD1d/glycolipide. Un sous-type distinct de cellules iNKT, dont l'origine et l'homéostasie sont encore mal connues, produit la cytokine pro-inflammatoire IL-17. Dans ce travail, j'ai montré que les lymphocytes iNKT émigrés thymiques récents sont identifiés spécifiquement par l'expression de Nrp-1. Les lymphocytes iNKT producteurs d'IL-17 expriment Nrp-1 et dépendent de l'export thymique. D'autre part, Nrp-1 est exprimé par les thymocytes immatures en division et certains lymphocytes Tαβ conventionnels mémoires en prolifération homéostatique rapide. In vitro, l'activation des lymphocytes T par le TCR induit l'expression de Nrp-1 de manière dépendante de la voie de signalisation Ca2+/calcineurine/NFAT. L'expression de Nrp-1 dans les lymphocytes T activés les sensibilise aux effets régulateurs de Sema3A et TGF-β1. En conclusion, ces résultats apportent de nouvelles données concernant l'expression et la fonction de Nrp-1 dans le système immunitaire. Plus généralement, cette étude permet d'envisager des stratégies thérapeutiques ciblant les processus dépendants de Nrp-1 dans les pathologies du système immunitaire et du système nerveux ou les cancers.
55

CD4+CD25+ T regulatory cells in multiple sclerosis /

Putheti, Prabhakar, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
56

Regulation of marginal zone B cell migration in the primary IgM antibody response /

Rubtsov, Anatoly V. January 2007 (has links)
Thesis (Ph.D. in Immunology) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 146-169). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;
57

Impacto clínico da recuperação linfocitária precoce na reconstituição imunológica pós transplante alogênico de células tronco hematopoiéticas

Costa, Lisandra Della January 2012 (has links)
Introdução: O transplante de células tronco hematopoiéticas é capaz de curar as doenças hematológicas. O papel da repopulação linfocitária precoce no período pós transplan te visa combater a células neoplásicas que resistiram ao regime de condicionamento e prevenir as infecções oportunistas graves. Sendo assim, uma contagem elevada de linfócitos no período pós transplante é capaz de reduzir a mortalidade relacionada ao transplante (TRM), melhorar a sobrevida livre de doença e reduzir a taxa de recidiva. Objetivos: Avaliar a recuperação linfocitária precoce no D+21 e D+30 pós transplante correlacionado com a taxa de recidiva da doença de base, mortalidade, sobrevida global e livre de doença. Analisar a freqüência das complicações infecciosas neste período. Métodos: Analisado o número absoluto de linfócitos no D+21 e D+30 pós transplante de células tronco hematopoiéticas. Conforme dados da literatura definiu-se no D+21 e no D+30 aqueles com número absoluto de linfócitos abaixo e acima de 300 e se correlacionou os dados obtidos com a taxa de óbito, taxa de recidiva, sobrevida global em 5 anos, sobrevida livre de doença, em 5 anos, TRM em 100 dias. e mortalidade não relacionada a recaída (NRM). Resultados: Neste estudo foram incluídos 100 pacientes portadores das seguintes neoplasias hematológicas: leucemia mielóide aguda, leucemia linfocítica aguda, leucemias secundárias e síndrome mielodisplásica. Destes, 55 pacientes eram do sexo masculino e 45 do sexo feminino. A média de idade foi de 27,9 anos (mínima 9 meses e máxima 55 anos). A mediana do tempo de seguimento foi de 601 dias (IC 95% 106-1845). A mediana de CD 34 infundidos foi de 4,0 (IC 95% 2,4-5,7) e quanto a origem destas células CD 34 infundidas 85% foram de medula óssea (MO), 12% periférica (PBSC) e 3% sangue de cordão umbilical (SCU). Quanto ao tipo de condicionamento realizado 22% foram não mieloablativos e 78% mieloablativos.A mediana de linfócitos no D+21 foi de 460 (IC 95% 0 - 6250) e no D+30 foi de 760 (IC 95% 40-6370). Com relação a taxa de infecções observou-se que 19% das infecções foram de etiologia viral, 65 % bacteriana e 17% fúngicas. A sobrevida global (OS) em 5 anos foi de 44 % , sobrevida livre de doença (DFS) foi de 37,7% , a mortalidade relacionada ao transplante (TRM) em 100 dias foi de 32,5%. E a mortalidade não relacionada a recidiva (NRM) em 5 anos foi de 40,2%. No desfecho óbito observamos que 69% dos pacientes que foram a óbito no D+21 tinham linfócitos abaixo de 300, e 43,9% tinham linfócitos acima de 300 (p<0,05). Pacientes com valores menores que 300 no dia 30 tem 2,20 vezes o risco de irem a óbito quando comparados com aqueles com valores acima de 300 (IC 95% 1,03-4,69) ajustado para DECH e CD34. Pacientes com valores menores que 300 no dia 30 tem 3,76 vezes o risco de irem a óbito em menos de 100 dias quando comparados com aqueles com valores acima de 300 (IC 95% 1,23-11,46) Conclusões: A reconstituição linfocitária precoce (> 300) no D+21 e no D+30 melhora a sobrevida global e livre de doença, bem como reduz a taxa de recidiva da doença de base e reduz a mortalidade. / Background: The role of repopulating lymphocyte after allogenic stem cell transplantation (SCT) includes the prevention of serious infections and attacking residual tumor cells in the early post transplant phase. Therefore, the current study analysed the role of the absolute lymphocyte count (ALC) on day 21 and 30 after SCT in predicting transplant outcomes of patients in terms of the risk of transplant related mortality (TRM) recurrence of original disease and risk of opportunistic infections. Objective: Evaluate early lymphocyte recovery on D +21 and D +30 posttransplant correlated with the rate of recurrence of the underlying disease, mortality, overall survival and disease free survival. Analyzed the frequency of infectious complications in this period. Methods: Analyzed the absolute lymphocyte count in the D +21 and D +30 after hematopoietic stem cell transplantation. According to literature data set the we correlate the absolute lymphocyte count in the D +21D +30 below and above 300 these data with the rate of death, relapse rate, overall survival in 5 years, disease-free survival in 5 years , TRM in 100 days and mortality unrelated to relapse (NRM). Results : Included in the study 100 patients with the following hematologic malignancies: acute myeloid leukemia, acute lymphocytic leukemia, secondary leukemia and myelodysplastic syndrome. Of these, 55 patients were male and 45 female. The average age was 27.9 years (minimum 9 months and maximum 55 years). The median follow-up was 601 days (95% CI 106-1845). The CD 34 median that was infused was 4.0 (95% CI 2.4 to 5.7).The source of stem cells infused was 85% of bone marrow (BM), peripheral 12% (PBSC) and 3 % of umbilical cord blood (UCB). Regarding the type of conditioning performed 22% were non myeloablative and 78% of lymphocytes were mieloablativos. The median of absolute lymphocyte count in the D +21 was 460 (95% CI 0 to 6250) and D +30 was 760 (95% CI 40- 6370 ). Regarding the rate of infections were observed 19% viral infections , bacterial in 65% and fungal in 17%. Overall survival (OS) at 5 years was 44%, disease-free survival (DFS) was 37.7%, transplant related mortality (TRM) in 100 days was 32.5%. Non relapsed mortality (NRM) at 5 years was 40.2%. The death rate found that 69% of patients who died at the D +21 had presented lymphocytes count below 300, and 43.9% were above 300 lymphocytes (p <0.05). Patients with counts less than 300 in D+30 presented 2.20 times risk of death when compared with those who presented values above 300 (95% CI 1.03 to 4.69) adjusted for GVHD and CD34. Patients presenting values less than 300 in 30 days have 3.76 times more risk of death in less than 100 days compared with those with values above 300 (95% CI 1.23 to 11.46). Conclusions: The early lymphocyte reconstitution (> 300) in D +21 D +30 improves overall survival and disease-free and reduces the relapse rate of the underlying disease and reduces mortality.
58

Impacto clínico da recuperação linfocitária precoce na reconstituição imunológica pós transplante alogênico de células tronco hematopoiéticas

Costa, Lisandra Della January 2012 (has links)
Introdução: O transplante de células tronco hematopoiéticas é capaz de curar as doenças hematológicas. O papel da repopulação linfocitária precoce no período pós transplan te visa combater a células neoplásicas que resistiram ao regime de condicionamento e prevenir as infecções oportunistas graves. Sendo assim, uma contagem elevada de linfócitos no período pós transplante é capaz de reduzir a mortalidade relacionada ao transplante (TRM), melhorar a sobrevida livre de doença e reduzir a taxa de recidiva. Objetivos: Avaliar a recuperação linfocitária precoce no D+21 e D+30 pós transplante correlacionado com a taxa de recidiva da doença de base, mortalidade, sobrevida global e livre de doença. Analisar a freqüência das complicações infecciosas neste período. Métodos: Analisado o número absoluto de linfócitos no D+21 e D+30 pós transplante de células tronco hematopoiéticas. Conforme dados da literatura definiu-se no D+21 e no D+30 aqueles com número absoluto de linfócitos abaixo e acima de 300 e se correlacionou os dados obtidos com a taxa de óbito, taxa de recidiva, sobrevida global em 5 anos, sobrevida livre de doença, em 5 anos, TRM em 100 dias. e mortalidade não relacionada a recaída (NRM). Resultados: Neste estudo foram incluídos 100 pacientes portadores das seguintes neoplasias hematológicas: leucemia mielóide aguda, leucemia linfocítica aguda, leucemias secundárias e síndrome mielodisplásica. Destes, 55 pacientes eram do sexo masculino e 45 do sexo feminino. A média de idade foi de 27,9 anos (mínima 9 meses e máxima 55 anos). A mediana do tempo de seguimento foi de 601 dias (IC 95% 106-1845). A mediana de CD 34 infundidos foi de 4,0 (IC 95% 2,4-5,7) e quanto a origem destas células CD 34 infundidas 85% foram de medula óssea (MO), 12% periférica (PBSC) e 3% sangue de cordão umbilical (SCU). Quanto ao tipo de condicionamento realizado 22% foram não mieloablativos e 78% mieloablativos.A mediana de linfócitos no D+21 foi de 460 (IC 95% 0 - 6250) e no D+30 foi de 760 (IC 95% 40-6370). Com relação a taxa de infecções observou-se que 19% das infecções foram de etiologia viral, 65 % bacteriana e 17% fúngicas. A sobrevida global (OS) em 5 anos foi de 44 % , sobrevida livre de doença (DFS) foi de 37,7% , a mortalidade relacionada ao transplante (TRM) em 100 dias foi de 32,5%. E a mortalidade não relacionada a recidiva (NRM) em 5 anos foi de 40,2%. No desfecho óbito observamos que 69% dos pacientes que foram a óbito no D+21 tinham linfócitos abaixo de 300, e 43,9% tinham linfócitos acima de 300 (p<0,05). Pacientes com valores menores que 300 no dia 30 tem 2,20 vezes o risco de irem a óbito quando comparados com aqueles com valores acima de 300 (IC 95% 1,03-4,69) ajustado para DECH e CD34. Pacientes com valores menores que 300 no dia 30 tem 3,76 vezes o risco de irem a óbito em menos de 100 dias quando comparados com aqueles com valores acima de 300 (IC 95% 1,23-11,46) Conclusões: A reconstituição linfocitária precoce (> 300) no D+21 e no D+30 melhora a sobrevida global e livre de doença, bem como reduz a taxa de recidiva da doença de base e reduz a mortalidade. / Background: The role of repopulating lymphocyte after allogenic stem cell transplantation (SCT) includes the prevention of serious infections and attacking residual tumor cells in the early post transplant phase. Therefore, the current study analysed the role of the absolute lymphocyte count (ALC) on day 21 and 30 after SCT in predicting transplant outcomes of patients in terms of the risk of transplant related mortality (TRM) recurrence of original disease and risk of opportunistic infections. Objective: Evaluate early lymphocyte recovery on D +21 and D +30 posttransplant correlated with the rate of recurrence of the underlying disease, mortality, overall survival and disease free survival. Analyzed the frequency of infectious complications in this period. Methods: Analyzed the absolute lymphocyte count in the D +21 and D +30 after hematopoietic stem cell transplantation. According to literature data set the we correlate the absolute lymphocyte count in the D +21D +30 below and above 300 these data with the rate of death, relapse rate, overall survival in 5 years, disease-free survival in 5 years , TRM in 100 days and mortality unrelated to relapse (NRM). Results : Included in the study 100 patients with the following hematologic malignancies: acute myeloid leukemia, acute lymphocytic leukemia, secondary leukemia and myelodysplastic syndrome. Of these, 55 patients were male and 45 female. The average age was 27.9 years (minimum 9 months and maximum 55 years). The median follow-up was 601 days (95% CI 106-1845). The CD 34 median that was infused was 4.0 (95% CI 2.4 to 5.7).The source of stem cells infused was 85% of bone marrow (BM), peripheral 12% (PBSC) and 3 % of umbilical cord blood (UCB). Regarding the type of conditioning performed 22% were non myeloablative and 78% of lymphocytes were mieloablativos. The median of absolute lymphocyte count in the D +21 was 460 (95% CI 0 to 6250) and D +30 was 760 (95% CI 40- 6370 ). Regarding the rate of infections were observed 19% viral infections , bacterial in 65% and fungal in 17%. Overall survival (OS) at 5 years was 44%, disease-free survival (DFS) was 37.7%, transplant related mortality (TRM) in 100 days was 32.5%. Non relapsed mortality (NRM) at 5 years was 40.2%. The death rate found that 69% of patients who died at the D +21 had presented lymphocytes count below 300, and 43.9% were above 300 lymphocytes (p <0.05). Patients with counts less than 300 in D+30 presented 2.20 times risk of death when compared with those who presented values above 300 (95% CI 1.03 to 4.69) adjusted for GVHD and CD34. Patients presenting values less than 300 in 30 days have 3.76 times more risk of death in less than 100 days compared with those with values above 300 (95% CI 1.23 to 11.46). Conclusions: The early lymphocyte reconstitution (> 300) in D +21 D +30 improves overall survival and disease-free and reduces the relapse rate of the underlying disease and reduces mortality.
59

Impacto clínico da recuperação linfocitária precoce na reconstituição imunológica pós transplante alogênico de células tronco hematopoiéticas

Costa, Lisandra Della January 2012 (has links)
Introdução: O transplante de células tronco hematopoiéticas é capaz de curar as doenças hematológicas. O papel da repopulação linfocitária precoce no período pós transplan te visa combater a células neoplásicas que resistiram ao regime de condicionamento e prevenir as infecções oportunistas graves. Sendo assim, uma contagem elevada de linfócitos no período pós transplante é capaz de reduzir a mortalidade relacionada ao transplante (TRM), melhorar a sobrevida livre de doença e reduzir a taxa de recidiva. Objetivos: Avaliar a recuperação linfocitária precoce no D+21 e D+30 pós transplante correlacionado com a taxa de recidiva da doença de base, mortalidade, sobrevida global e livre de doença. Analisar a freqüência das complicações infecciosas neste período. Métodos: Analisado o número absoluto de linfócitos no D+21 e D+30 pós transplante de células tronco hematopoiéticas. Conforme dados da literatura definiu-se no D+21 e no D+30 aqueles com número absoluto de linfócitos abaixo e acima de 300 e se correlacionou os dados obtidos com a taxa de óbito, taxa de recidiva, sobrevida global em 5 anos, sobrevida livre de doença, em 5 anos, TRM em 100 dias. e mortalidade não relacionada a recaída (NRM). Resultados: Neste estudo foram incluídos 100 pacientes portadores das seguintes neoplasias hematológicas: leucemia mielóide aguda, leucemia linfocítica aguda, leucemias secundárias e síndrome mielodisplásica. Destes, 55 pacientes eram do sexo masculino e 45 do sexo feminino. A média de idade foi de 27,9 anos (mínima 9 meses e máxima 55 anos). A mediana do tempo de seguimento foi de 601 dias (IC 95% 106-1845). A mediana de CD 34 infundidos foi de 4,0 (IC 95% 2,4-5,7) e quanto a origem destas células CD 34 infundidas 85% foram de medula óssea (MO), 12% periférica (PBSC) e 3% sangue de cordão umbilical (SCU). Quanto ao tipo de condicionamento realizado 22% foram não mieloablativos e 78% mieloablativos.A mediana de linfócitos no D+21 foi de 460 (IC 95% 0 - 6250) e no D+30 foi de 760 (IC 95% 40-6370). Com relação a taxa de infecções observou-se que 19% das infecções foram de etiologia viral, 65 % bacteriana e 17% fúngicas. A sobrevida global (OS) em 5 anos foi de 44 % , sobrevida livre de doença (DFS) foi de 37,7% , a mortalidade relacionada ao transplante (TRM) em 100 dias foi de 32,5%. E a mortalidade não relacionada a recidiva (NRM) em 5 anos foi de 40,2%. No desfecho óbito observamos que 69% dos pacientes que foram a óbito no D+21 tinham linfócitos abaixo de 300, e 43,9% tinham linfócitos acima de 300 (p<0,05). Pacientes com valores menores que 300 no dia 30 tem 2,20 vezes o risco de irem a óbito quando comparados com aqueles com valores acima de 300 (IC 95% 1,03-4,69) ajustado para DECH e CD34. Pacientes com valores menores que 300 no dia 30 tem 3,76 vezes o risco de irem a óbito em menos de 100 dias quando comparados com aqueles com valores acima de 300 (IC 95% 1,23-11,46) Conclusões: A reconstituição linfocitária precoce (> 300) no D+21 e no D+30 melhora a sobrevida global e livre de doença, bem como reduz a taxa de recidiva da doença de base e reduz a mortalidade. / Background: The role of repopulating lymphocyte after allogenic stem cell transplantation (SCT) includes the prevention of serious infections and attacking residual tumor cells in the early post transplant phase. Therefore, the current study analysed the role of the absolute lymphocyte count (ALC) on day 21 and 30 after SCT in predicting transplant outcomes of patients in terms of the risk of transplant related mortality (TRM) recurrence of original disease and risk of opportunistic infections. Objective: Evaluate early lymphocyte recovery on D +21 and D +30 posttransplant correlated with the rate of recurrence of the underlying disease, mortality, overall survival and disease free survival. Analyzed the frequency of infectious complications in this period. Methods: Analyzed the absolute lymphocyte count in the D +21 and D +30 after hematopoietic stem cell transplantation. According to literature data set the we correlate the absolute lymphocyte count in the D +21D +30 below and above 300 these data with the rate of death, relapse rate, overall survival in 5 years, disease-free survival in 5 years , TRM in 100 days and mortality unrelated to relapse (NRM). Results : Included in the study 100 patients with the following hematologic malignancies: acute myeloid leukemia, acute lymphocytic leukemia, secondary leukemia and myelodysplastic syndrome. Of these, 55 patients were male and 45 female. The average age was 27.9 years (minimum 9 months and maximum 55 years). The median follow-up was 601 days (95% CI 106-1845). The CD 34 median that was infused was 4.0 (95% CI 2.4 to 5.7).The source of stem cells infused was 85% of bone marrow (BM), peripheral 12% (PBSC) and 3 % of umbilical cord blood (UCB). Regarding the type of conditioning performed 22% were non myeloablative and 78% of lymphocytes were mieloablativos. The median of absolute lymphocyte count in the D +21 was 460 (95% CI 0 to 6250) and D +30 was 760 (95% CI 40- 6370 ). Regarding the rate of infections were observed 19% viral infections , bacterial in 65% and fungal in 17%. Overall survival (OS) at 5 years was 44%, disease-free survival (DFS) was 37.7%, transplant related mortality (TRM) in 100 days was 32.5%. Non relapsed mortality (NRM) at 5 years was 40.2%. The death rate found that 69% of patients who died at the D +21 had presented lymphocytes count below 300, and 43.9% were above 300 lymphocytes (p <0.05). Patients with counts less than 300 in D+30 presented 2.20 times risk of death when compared with those who presented values above 300 (95% CI 1.03 to 4.69) adjusted for GVHD and CD34. Patients presenting values less than 300 in 30 days have 3.76 times more risk of death in less than 100 days compared with those with values above 300 (95% CI 1.23 to 11.46). Conclusions: The early lymphocyte reconstitution (> 300) in D +21 D +30 improves overall survival and disease-free and reduces the relapse rate of the underlying disease and reduces mortality.
60

Intérêt du couple CD5/CD6 dans les lymphocytes B humains / Interest of the CD5 / CD6 couple in human B lymphocytes

Le Dantec, Christelle 02 July 2012 (has links)
Issues d'un gène ancestral commun, les molécules CD5 et CD6 sont présentes à la surface de tous les lymphocytes T (LT) matures ainsi qu'à la surface de certains lymphocytes B (LB). Ces deux protéines font partie de la famille des « Scavenger Receptor Cystein Rich » (SRCR) protéines mais la régulation, l'expression et les fonctions de ces deux molécules ne sont pas totalement résolues. Ainsi, CD5 est impliquée dans la régulation du récepteur à l’antigène des LB et des LT, dans la tolérance des LB et elle est présente à la surface des LB régulateurs. A l’opposé, CD6 possède un rôle dans la prolifération des lymphocytes, la survie, la migration et l’adhésion cellulaire. Les expressions de CD5 et CD6 diffèrent au sein des LB normaux ainsi qu'en pathologie. Dans le cadre du lupus érythémateux systémique (LES), le nombre de molécules CD5 à la surface des LB CD5+ est réduit. Dans une autre maladie auto-immune (MAI), le Syndrome de Gougerot Sjögren (SGS), l'expression de CD6 à la membrane des LB n'est pas affectée mais la distribution des LB mémoires CD6+, mais pas des LB naïfs, est modifiée par rapport aux témoins sains. En effet, les LB CD6+ sont sous représentés dans le sang périphérique et ce, en raison de leur délocalisation dans les glandes salivaires (GS) des patients. Cette délocalisation est liée à la surexpression d’ALCAM, le ligand naturel de CD6, par les cellules épithéliales au cours du SGS. L'étude de la diminution de l'expression de CD5 à la surface des LB de patients atteints de LES a permis de montrer qu'il existait un défaut dans le processus de la méthylation de l'ADN chez ces patients. Ce même défaut a été retrouvé dans les GS de patients atteints de SGS. Enfin, les LB de patients atteints de leucémie lymphoïde chronique (LLC) sont porteurs des deux molécules à leur membrane. Nous avons testé l'effet in vitro et in vivo d'un l'anticorps monoclonal (Acm) humanisé anti-CD6, T1H, dans la LLC. De façon intéressante, il s’avère que cet Acm favorise la lyse des LB de LLC et ceci, de façon équivalente au rituximab dans un modèle murin in vivo. T1H est internalisé par les LT et est donc inefficace sur ces cellules. Ces résultats nous permettent de conclure que même si les molécules CD5 et CD6 sont proches phylogénétiquement, elles possèdent des fonctions et des modes de régulation différents entre les LB et les LT mais aussi au sein des différentes populations de LB. Une meilleure compréhension des fonctions et des modes d'actions de ces deux protéines ouvre des perspectives thérapeutiques dans le traitement des MAI et de la LLC. / Derived from a common ancestral gene, CD5 and CD6 molecules are present on the surface of all mature T lymphocytes (LT) and some B lymphocytes (LB). These two proteins are members of the "Scavenger Receptor Cystein Rich" family proteins (SRCR) but the regulation, the expression and the function of these molecules is not totally resolved. CD5 is involved in the regulation of antigen receptor in LB and in LT, in the LB tolerance and is present on the surface of regulator B cells. In contrast, CD6 plays a role in lymphocyte proliferation, survival, migration, and cell adhesion. Expressions of CD5 and CD6 differ within normal LB and and LB present in different in pathologies. In the context of systemic lupus erythematosus (LES), the number of CD5 molecules on the surface of CD5+ LB is reduced. In another autoimmune disease (MAI), the Sjogren Syndrome (SS), the expression of CD6 at the membrane of B cells is not affected but the distribution of CD6 + memory LB but not naive LB is changed compared to healthy controls. Indeed, LB CD6 + are underrepresented in the peripheral blood and, it’s due to their relocation in the salivary glands (GS) of patients. This relocation is related to overexpression of ALCAM, the natural ligand of CD6, by epithelial cells in SS. The study of the decreased expression of CD5 on the surface of LB SLE patients has shown that there was a defect in the process of DNA methylation in these patients. The same defect was found in the GS of SS patients. Finally, B cells from chronic lymphocytic leukemia patients (CLL) are holders of the two molecules on their membrane. We tested the effect in vitro and in vivo of a humanized monoclonal antibody (mAb) anti-CD6, T1H, in the CLL. Interestingly, it appears that this mAb promotes lysis of CLL LB and this effect is equivalent to the one that rituximab was shown to have in an in vivo mouse model. T1H is internalized by LT and is therefore ineffective on these cells. These results allow us to conclude that even if the CD5 and CD6 molecules are phylogenetically close, they have different functions and modes of regulation between LB and LT but also within different populations of LB. A better understanding of their functions and action pathway of these two proteins opens up therapeutic perspectives for the treatment of MAI and CLL.

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