Introdução: A micose fungóide foliculotrópica (MFF) é subtipo de linfoma cutâneo de células T que atinge especialmente o folículo piloso e parece ter prognóstico mais reservado. Informações clínicas sobre a população acometida por linfomas cutâneos no Brasil são escassas. O fenômeno de imunoprivilégio (IP) diz respeito à habilidade de alguns órgãos em permanecer protegidos contra reações inflamatórias. Tem sido sugerido que o folículo piloso normal represente um local de IP. Nesse estudo aventou-se a possibilidade de haver uma quebra no equilíbrio desse fenômeno na MFF, com alteração na expressão de moléculas do complexo maior de histocompatibilidade (MHC) e na expressão de MHC não-clássicos (HLA-G), com algum papel no mecanismo do foliculotropismo. Os objetivos foram: descrever o perfil clínico-epidemiológico de paciente com MFF, descrever a histologia e imunofenótipo dos casos de MFF e investigar os mecanismos envolvidos na predileção dos linfócitos atípicos pelo folículo piloso. Metodologia: Os prontuários de pacientes com diagnóstico de MFF provenientes do ambulatório de Linfomas Cutâneos da Faculdade de Medicina da Universidade de São Paulo (FMUSP) foram revisados (n=33). O material histológico de biópsias de pele dos pacientes com MFF provenientes dos ambulatórios de Linfomas Cutâneos da FMUSP e da Northwestern University foi analisado por meio de escala semi-quantitativa (n=43). Na coloração de hematoxilina-eosina foram avaliados os seguintes parâmetros: infiltrado neoplásico epidérmico, infiltrado neoplásico dérmico, presença de acantose/espongiose, de mucinose folicular, de fibroplasia do tecido conjuntivo, de eosinófilos, de plasmócitos, o tamanho celular e o grau de dano folicular. Analisou-se a positividade do infiltrado neoplásico para os seguintes marcadores celulares: CD1a, CD56, TIA-1 e CD117. As expressões do complexo de histocompatibilidade HLA-G e do MHCII no infiltrado celular e no epitélio folicular foram investigadas no grupo de pacientes com MFF e comparadas com o grupo de pacientes com micose fungóide clássica (MFC) e pele normal. A expressão do complexo de histocompatibilidade MHCII também foi investigada na epiderme. Resultados: A mediana das idades ao diagnóstico foi de 46 anos com 61% dos pacientes classificados como portadores de estágio avançado. A proporção entre homens e mulheres foi de 1,54 e a mediana de duração de doença antes do diagnóstico foi de três anos. Ao final de três anos de acompanhamento, 67% dos casos estavam vivos com a doença. O prurido foi relatado em 82% dos casos. Histologicamente, encontrou-se associação entre a presença de eosinófilos e de plasmócitos com fibroplasia do tecido conjuntivo. Observou-se diminuição da expressão do HLA-G no epitélio folicular nos grupos MFF e MFC em relação à pele normal. Observou-se aumento da expressão do MHCII no epitélio folicular na MFF em comparação à pele normal e na epiderme na MFC quando comparada à MFF. Conclusões: Dados clínicos da população estudada assemelharam-se aos dados da literatura como estágio avançado ao diagnóstico e prognóstico reservado. Cerca de metade dos casos de MFF foi positiva para o marcador citotóxico TIA-1. Demonstrou-se haver um provável colapso do imunoprivilégio folicular nos linfomas cutâneos com expressão diminuída de moléculas HLA-G em comparação à pele normal. O aumento da expressão do MHCII poderia relaciona-se com o foliculotropismo na MFF e com o epidermotropismo na MFC / Introduction: Folliculotropic mycosis fungoides (FMF) is a subtype of cutaneous T cells lymphoma affecting mainly the hair follicle and seems to have a less favorable prognosis. Clinical information on the population affected by cutaneous lymphomas in Brazil is scarce. The immune privilege (IP) phenomenon involves the ability of some body sites remaining protected from inflammatory reactions. It has been suggested that normal hair follicle represents an IP location. We hypothesized that a collapse of this phenomenon would occur in FMF, with changes in the expression of classical major histocompatibility molecules (MHC) and in the expression of nonclassical MHC molecules (HLA-G) with a role in folliculotropism mechanism. The objectives of this study were to describe the clinical and epidemiological profile of patients with MFF, describe the histology and immunophenotype of cases of MFF and investigate the expression of MHC molecules. Methods: The medical records of patients from the outpatient Cutaneous Lymphoma Clinic of the University of Sao Paulo Medical School (FMUSP) diagnosed with MFF were reviewed (n = 33). The histological material from skin biopsies of patients with MFF from the Cutaneous Lymphomas Clinic of FMUSP and Northwestern University was stained and evaluated by semi-quantitative scale. In hematoxylin-eosin staining the following parameters were evaluated: epidermal neoplastic infiltrate, dermal neoplastic infiltrate, acanthosis/spongiosis, follicular mucinosis, connective tissue fibroplasia, presence of eosinophils and plasma cells, cell size and degree of follicular damage. We analyzed the positivity of the neoplastic infiltrate for the following cellular markers: CD1a, CD56, TIA-1, and CD117. Finally, the expression of histocompatibility complex HLA-G and MHC II in the neoplastic infiltrate and the follicular epithelium was investigated in MFF group and compared to patients with classical mycosis fungoides (CMF) and to normal skin. MHCII expression in the epidermis was also investigated. Results: The median age at diagnosis was 46 years, with 61% classified as advanced stage disease. The ratio between men and women was 1.54, the median disease duration before diagnosis was three years. After a median time of follow-up of three years, 67% of the cases were alive with disease. Pruritus was reported in 82% of the cases. Histologically, an association between the presence of eosinophils and plasma cells with fibroplasia of collagen was found. There was a decrease of HLA-G expression in the follicular epithelium in MFF and CMF groups compared to normal skin. There was an increase of MHCII expression in the follicular epithelium in FMF group compared to normal skin. There was an increased MHCII expression in the epidermis in CMF compared to FMF. Conclusions: Clinical data from the studied population were similar to the previous literature in relation to advanced stage at diagnosis and prognosis. There was a relationship between the presence of eosinophils and plasma cells in neoplastic infiltrate and the connective tissue fibrosis. Near half of the cases of FMF was positive for the cytotoxic marker TIA-1. A possible hair follicle immune privilege collapse was suggested by a decreased expression of HLA-G molecules in FMF and CMF compared to normal skin. Increased MHCII expression appears to be involved in the folliculotropism of FMF and epidermotropism of CMF

Muitos estudos de câncer têm sido desenvolvidos, mas os mecanismos moleculares da tumorigênese e a resposta imune contra tumores não foi completamente elucidada. RMAS é uma linhagem celular mutante derivada de RMA. Ao contrário da última, RMAS é deficiente de MHC I e, portanto, é avlvo de células NK. O objetivo deste trabalho foi o uso deste par de células para estabelecer modelos murinos que possam ser usados para entender a resposta imune entre células CD8 e NK contra tumor e investigar o efeito da expressão de moléculas antiapoptóticas no comportamento tumoral in vivo. Essa abordagem pode prover informações relevantes para o desenvolvimento de novas terapias. Para desenvolver células EGFP, foi usado um vetor retroviral bicistrônico contendo o gene Egfp. Para desenvolver os modelos experimentais, camundongos C57BL6 WT foram injetados iv com diferentes números de células e curvas de sobrevivência foram geradas. Os padrões de doença e infiltração tumoral foram observadas por análises macroscópica, microscópica e por detecção de EGFP em tecidos. In vivo, células RMA. induziram paralisia enquanto RMA-S.Egfp, ascite. RMA.Egfp infiltrou a medula óssea enquanto RMA-S.Egfp, tecidos diferentes como fígado, rins e peritôneo, mas não a medula óssea. Os sinais clínicos apareceram após 15 dias da inoculação de >104 células e a morte, em 30 dias. Números <103 células não induziram doença nem morte, mas protegeram de ambas quando re-inoculadas 106 células RMA.Egfp. Camundongos CD4KO e CD8KO paralisaram e morreram antes do que os WT. Células RMA.BclW.Egfp foram mais resistentes a apoptose do que células RMA.Egfp in vitro e provocaram características clínicas piores: paralisia e morte anteriores, inchaço de membros e hemorragia de fígado e rins. / Many cancer studies have been developed, however the molecular mechanisms of tumorigenesis and immune responses to tumor is not completely elucidated. RMAS cells are a mutant lymphoma line derived from RMA cells. In contrast to the latter, RMAS are deficient in MHCI and, therefore, are targets for NK cells. Our aims were use these pair of cells to establish mouse models that can be used to understand CD8T vs NK cell immune responses to tumors and investigate the effect of expression of antiapoptotic molecules in tumor behavior in vivo. The combination of these approaches should provide relevant information for the development of novel immunotherapy. To develop EGFP cells we used a bicistronic retroviral vector containing Egfp gene. To develop the experimental models, WT C57BL/6 mice were iv injected with different cell numbers and survival curves were produced. In addition, clinical features and tumor spread was observed by macroscopy, microscopy and EGFP detection of tumor cell analysis in tissues. When injected in vivo, RMA.Egfp cells induced progressive paralysis while RMA-S.Egfp promoted ascites. RMA.Egfp cells infiltrated the bone marrow, while RMA-S.Egfp were found in different tissues such as liver, kidney and the peritoneum cavity, but were not found in bone marrow. The symptoms appeared 15 days post injection of >104 cells and the death was 30 days. Numbers of <103 cells do not induced pathology or death, but protected to paralysis and death when re-injected 106 RMA.Egfp cells. CD4KO and CD8KO mice showed paralysis and death earlier than WT mice. RMA.BclW.Egfp cells were more resistant to apoptosis than RMA.Egfp in vitro and induced worse clinical features in vivo: earlier paralysis and death, swelling of members, haemorragia of liver and kidneys.

La survie des lymphomes non hodgkiniens (LNH) en population générale s'est améliorée durant la dernière décennie. Pourtant, des disparités persistent, suggérant le rôle de certains facteurs comme les facteurs socio-économiques et des inégalités dans l’accès ou la qualité des soins.Entre 2002 et 2008, 1798 LNH diffus à grandes cellules B et folliculaire ont été diagnostiqués dans 3 registres spécialisés en hématologie (Basse Normandie, Côte d’Or et Gironde). De fortes inégalités territoriales entre les 3 zones registres sont observées concernant le lieu de leur prise en charge, les délais d'initiation au traitement ou la survie, mais aucune association entre le score de défavorisation (EDI) et ces trois critères n'a été mise en évidence.La survie s'est améliorée durant la période d'étude. Cette tendance positive peut être expliquée par l’usage de l'immunothérapie en 1ère ligne. La zone géographique de diagnostic,la spécialité médicale (onco-hématologie vs autres) sont indépendamment associées à une meilleure survie à 5 ans quel que soit l’âge. Enfin, l'amélioration de la survie chez les patients âgés (75-84 ans en particulier) peut s'expliquer par un bilan initial plus complet (TEP scan entrainant un « upstaging ») suivi de traitements plus agressifs.Le temps de déplacement était associé au lieu de prise en charge et à la survie, avec un pronostic défavorable des patients résidant à plus de 15 minutes du centre de référence le plus proche.Malgré les avancées thérapeutiques, de nombreux facteurs non biologiques peuvent affecter le pronostic des patients atteints de LNH. L'expertise des équipes prenant en charge ces maladies semble primordiale pour obtenir une prise en charge optimale. / Due to the addition of innovative treatment, survival of non-Hodgkin lymphoma (NHL) increased during the last decade. Nevertheless, disparities persist, suggesting the role of certain factors as socio-economic factors and disparities in the access or the quality of healthcare.Between 2002 and 2008, 1798 Diffuse Large B-cell (DLBCL) and follicular lymphomas werediagnosed in 3 hematological malignancies specialized registries (Basse-Normandie, Côted'Or and Gironde). Important territorial disparities between the 3 registries areas were observed regarding the place of care, the delay of treatment initiation or the survival whatever the age while there was no association with the deprivation score (EDI).The survival improved during the study period. This positive trend could be explained by the use of immunotherapy as 1st line therapy. The geographical area where the patient was diagnosed, the medical specialization (onco-hematology vs others departments) are independently associated with a better 5-years survival whatever the age.Finally, the improvement of the survival in elderly (especially 75-84 years) could be explained by better work up (higher TEP scan use leading to "upstaging") and thus to use more aggressive therapies. Also, the travel time was associated with the place of care and the survival, with a poorer prognosis for patients living more than 15 min from the closest reference center. Despite therapeutic advances, various non biological factors can affect the prognosis ofpatients with lymphomas. The notion of lymphoma-specific expertise seems to be essential to achieve optimal DLBCL care management and reopen the debate of centralization of NHLpatients care in hematology/oncology departments.

La leucémie myéloïde aiguë (LMA) est une maladie clonale hétérogène caractérisée par une prolifération immature des cellules myéloïdes et une défaillance de la moelle osseuse. Malgré les avancées rapides dans le domaine de la LMA, notamment concernant de nouvelles cibles thérapeutiques et une meilleure compréhension des mécanismes biologiques, le traitement clinique de la LMA reste inchangé et dépend du caryotype des patients. Lors des trois dernières décennies, la plupart des patients ont fini par récidiver et décéder de la maladie ; il n’y a encore aucun schéma thérapeutique standard qui améliore le pronostic et le traitement de la LMA.Les imidazoquinoxalines sont des dérivés de l’imiquimod qui présentent un effet immunomodulateur indirect et une activité anti-tumorale directe contre le mélanome et le lymphome à cellules T, provoquant l’inhibition de la croissance cellulaire et l’induction de l’apoptose par la voie dépendante des caspases . Nous avons étudié les effets des dérivés de la série imidazoquinoxaline, EAPB0203 et EAPB0503, sur des lignées de cellules humaines LMA. Nous avons montré que EAPB0503 inhibe la croissance de la lignée cellulaire LMA qui présente la mutation NPM-1 de manière dose et temps dépendants. Par rapport au dérivé EAPB0203 précédemment synthétisé, EAPB0503 a une activité inhibitrice plus forte sur les cellules OCI-AML3 ainsi que sur des cellules provenant de patients LMA. Nous avons démontré que EAPB0503 induit une dégradation médiée par les protéasomes deNPM-1 muté ainsi qu’un rétablissement de la localisation nucléolaire de NPM-1 sauvage conduisant à une inhibition de la prolifération des cellules OCI-AML3.EAPB0503 induit une apoptose massive comme démontré par l’analyse du cycle cellulaire avec une accumulation de cellules traitées en phase preG0. L’apoptose a été confirmée par la réponse positive au test de l’annexine V, le clivage de PARP et la dissipation du potentiel membranaire mitochondrial dans les cellules OCI-AML3 traitées.En outre, EAPB0503 a augmenté les niveaux d’expression et de phosphorylation de p53.Ces résultats, concernant l’arrêt de la croissance cellulaire et l’apoptose, sélectivement dans les cellules LMA présentant la mutation NPM-1, renforcent l’idée d’un ciblage de l’oncoprotéine NPM-1 muté pour éliminer les cellules leucémiques et justifient une évaluation préclinique plus large puis une évaluation clinique pour ce candidat médicament prometteur.En conclusion, nos études mettent en évidence l'utilisation d’EAPB0503 comme un candidat médicament prometteur qui présente une activité anti-tumorale encourageante et qui devrait faire l’objet d’études précliniques dans le cadre d’une thérapie ciblée contre la LMA. / Acute myeloid leukemia (AML) is a heterogeneous clonal disorder characterized by immature myeloid cell proliferation and bone marrow failure. Although the remarkable improvements in the field and regarding new drug targets and better understanding of the biology, the clinical treatment of AML remains unchanged and depending on karyotype of patients. For the last thirty years with the majority of patients, in the end, relapsing and dying of the disease, there is no standard regimen that improves prognosis and treat AML yet.Imidazoquinoxalines are imiquimod derivatives with indirect immunomodulatory effect and direct antitumor activity on melanoma and T-cell lymphoma, attributed to growth inhibition and induction of apoptosis through caspase-dependent pathway. We examined the effects of imidazoquinoxaline derivatives, EAPB0203 and EAPB0503, on human AML cells. We found that EAPB0503 inhibit cell growth of AML cell line that harbors the NPM-1 mutation in a time- and dose-dependent way. Compared to the previously synthesized EAPB0203, EAPB0503 has a more pronounced inhibitory activity on OCI-AML3 cells and cells derived from AML patients as well. We demonstrated that the EAPB0503 induces proteasome-mediated degradation of mutant NPM-1, and restoration of the nucleolar localization of the NPM-1wt leading to an inhibition of the proliferation of OCI-AML3 cells.EAPB0503 induced massive apoptosis as demonstrated with the cell cycle analysis by the accumulation of treated cells in the preG0 region. Apoptosis has been confirmed by Annexin V positivity, PARP cleavage, and dissipation of mitochondrial membrane potential in treated OCI-AML3 cells.Furthermore, EAPB0503 increased the expression and phosphorylation levels of p53.These results in growth inhibition and apoptosis, selectively in AML cells that harbor the NPM-1 mutation reinforce the idea targeting NPM-1m oncoprotein to eradicate leukemic cells and warrant a broader preclinical then clinical evaluation of this promising drug.In conclusion, our studies highlight the use of EAPB0503 as a promising anti-tumor activity to be investigated preclinically in AML targeted therapy.

Background: Celiac disease (CD) is an autoimmune disorder that affects genetically susceptible individuals and is induced by dietary gluten. Treatment consists of a lifelong gluten-free diet. CD is common and affects about 1% of the general population. The classic symptoms include diarrhea and malabsorption, but many patients have only mild symptoms or no symptoms at all. The proportion of individuals presenting with atypical symptoms or discovered only when investigating an associated condition of CD is increasing. Aims: The aim of this thesis was to investigate the risk of possible associated disorders through Swedish population-based registers. The objective was to gain more information on the consequences of having CD and to identify high risk groups where screening may be considered. Materials and methods: We used the Swedish hospital discharge register to examine the risk of liver disease, autoimmune heart disease, Addison’s disease and thyroid disorders in a cohort of about 14,000 individuals with CD and an age and sex matched reference population of 70,000 individuals. In the last study we used all regional pathology registers and the cancer registry to examine the risk of hematopoietic cancer, including lymphoma in three different cohorts: I) 28,810 individuals with CD; II) 12,681 individuals with small intestinal mucosal inflammation but without villous atrophy; and III) 3552 individuals with latent CD (a positive serology test for CD with a normal small intestinal biopsy). Results: CD is statistically significantly associated with an increased risk of liver disease, Addison’s disease, thyroid disease and lymphoma. We also found an increased risk of lymphoma in individuals with small intestinal mucosal inflammation. There was no statistically significant association between autoimmune heart disease or leukemia and CD. Latent CD was not associated with any hematopoietic cancers. Conclusion: This thesis found a positive association between CD and a number of autoimmune and inflammatory disorders. Clinicians need to have a high awareness of this association and to test for these conditions when symptoms appear.

Alors que le rôle des cellules du système immunitaires innées sur la progression tumorale est l'objet d'une investigation croissante, le rôle des neutrophiles sur la sensibilité à la thérapie n'a pas été précédemment décrit. Jusqu’au présent, nous avons effectué des cocultures de neutrophiles et des différentes lignées cellulaires de lymphome non hodgkinien (LNH) en présence de divers agents cytotoxiques ou des thérapies ciblées. Afin d’évaluer l'effet du traitement sur la prolifération cellulaire et la mort des cellules, des marquages CFSE et DAPI ont été effectués respectivement, en utilisant la cytométrie en flux. Les neutrophiles ainsi que les cellules HL60 différenciées avec des propriétés de neutrophiles, ont atténué la sensibilité de cellules de lymphome à des agents anticancéreux in vitro, à la fois dans les modèles 2D et 3D. L'effet protecteur des neutrophiles a été testée in vivo en injectant des cellules de LNH et des neutrophiles chez des souris SCID/CB17 traités avec vincristine. La coinjection de neutrophiles réduit la sensibilité des cellules LNH à la chimiothérapie. Cet effet protecteur a été validé en utilisant des cellules primaires, purifiée à partir de patients atteints de leucémie lymphoïde chronique, exposés à des agents cytotoxiques ou des agents ciblés en présence de neutrophiles autologues. La protection par les neutrophiles est contact dépendante. Elle est médiée par l'interaction de CD11b et ICAM1, exprimé par les neutrophiles et les lymphocytes B, respectivement, et par la molécule d'adhésion CD44. Elle est également dépendante de Mcl1 et est partiellement abrogée par un composé anti-Mcl1 / While the role of innate immune cells on tumor progression is the object of increasing scrutiny, the role of neutrophils on sensitivity to therapy has not been previously described. To this end, we performed cocultures of freshly purified human neutrophils and different non- Hodgkin lymphoma (NHL) cell lines in the presence of various cytotoxic and targeted agents. CFSE and DAPI assays were performed to assess the therapeutic effect on cell proliferation and cell death, respectively, using flow cytometry. Neutrophils and differentiated HL60 cells with neutrophil-like properties attenuated the sensitivity of lymphoma cells to anti-cancer agents both in 2D and 3D models in vitro. The protective effect of neutrophils was tested in vivo using SCID/CB17 mice inoculated with NHL cells together with neutrophils, and treated with vincristine. The co-inoculation of neutrophils reduced the sensitivity of NHL cells to chemotherapy. Similar findings were made on primary cells, purified from patients diagnosed with chronic lymphocytic leukemia, exposed to cytotoxic agents or recently approved targeted agents (ibrutinib and idelalisib) in the presence of autologous neutrophils. Neutrophil-induced protection was dependent on cell-cell contact mediated by the interaction of CD11b and ICAM-1, expressed by neutrophils and B cells respectively, and by the adhesion molecule CD44. This protective effect was Mcl-1-dependent and was partially abrogated by an anti- Mcl-1 compound

No description available.

Mucosa associated lymphoid tissue (MALT) lymphoma is characterized by t(11;18)(q21;q21)/API2-MALT1, t(1;14)(p22;q32)/BCL10-IGH andt(14;18)(q32;q21)/IGH-MALT1, which commonly activate the NF-κB pathway. Gastric MALT lymphomas harbouring such translocation do not respond to Helicobacter pylori eradication, while those without translocation can be cured by antibiotics. To understand the molecular mechanism of MALT lymphoma with and without chromosome translocation, 24 cases (15 translocation-positive and 9 translocation-negative) of MALT lymphomas together with 7 follicular lymphomas and 7 mantle cell lymphomas were analysed by Affymetrix gene expression microarray platform. Unsupervised clustering showed that cases of MALT lymphoma were clustered as a single branch. However, within the MALT lymphoma group, translocation-positive cases were intermingled with translocation-negative cases. Gene set enrichment analysis (GSEA) of the NF-κB target genes and 4394 additional gene sets covering various cellular pathways, biological processes and molecular functions showed that translocation-positive MALT lymphomas were characterized by an enhanced expression of NF-κB target genes, particularly TLR6, CCR2, CD69 and BCL2, while translocation-negative cases were featured by active inflammatory and immune responses, such as IL8, CD86, CD28 and ICOS. Separate analyses of the genes differentially expressed between translocation-positive and negative cases and measurement of gene ontology term in these differentially expressed genes by hypergeometric test reinforced the above findings by GSEA. The differential expression of these NF-κB target genes between MALT lymphoma with and without translocation was confirmed by quantitative RT-PCR and immunohistochemistry or Western blot. Expression of TLR6, in the presence of TLR2, enhanced both API2-MALT1 and BCL10 mediated NF-κB activation in vitro. In addition, there was cooperation between expression of BCL10, MALT1 or API2-MALT1, and stimulation of the antigen receptor or CD40 or TLR in NF-κB activation as shown by both reporter assay and IκBα degradation. Interestingly, expression of BCL10 but not API2-MALT1 and MALT1, in the presence of LPS stimulation, also triggered IκBβ degradation, suggesting activation of different NF-κB dimers between these oncogenic products. Study by co-immunoprecipitation showed that BCL10 directly interacts with MALT1. Sub-cellular localisation experiments in BJAB B-cells, showed that BCL10 localisation was affected by MALT1. When BCL10 was over-expressed, the protein was predominantly expressed in the nuclei, but when MALT1 was over-expressed, BCL10 was mainly localised in the cytoplasm. When both BCL10 and MALT1 were over-expressed, BCL10 was expressed in the cytoplasm in the early hours when the protein level was low, but in both the cytoplasm and nuclei after 9 hours when the protein level was high. Over-expression of API2-MALT1 did not shown any apparent effect on BCL10 sub-cellular localisation in vitro. Finally, comparison of MALT lymphoma expression microarray with other lymphomas showed lactoferrin to be highly expressed in MALT lymphoma. This was confirmed by qRT-PCR, showing lactoferrin to be significantly over-expressed in MALT lymphoma compared to FL and MCL. Thus lactoferrin may be a potential marker for MALT lymphoma.

Le syndrome de Sézary (SS) est un variant leucémique et érythrodermique de lymphomes T cutanés. Il est caractérisé par la présence d’une population clonale de LT CD4+, présentant un noyau cérébriforme atypique, dans la peau, les ganglions lymphatiques et le sang périphérique. Après un bilan clinique, le diagnostic de cette pathologie est confirmé par l’analyse immunohistochimique d'une biopsie cutanée. Néanmoins, la cytomorphologie des cellules de Sézary circulantes n’est pas uniquement associée au SS. Notre laboratoire a identifié CD158k comme marqueur membranaire spécifique des cellules de Sézary. Ce récepteur offre un intérêt dans le diagnostic du SS et dans le suivi de l’évolution de la pathologie. Ainsi, nos résultats montrent qu’un immuno-marquage CD3+ CD158k+, analysé en cytométrie en flux, est une technique spécifique et sensible de détection de la cellule de Sézary par rapport à la cytomorphologie. Alors que dans plus de 30% des cas le SS passe inaperçu durant l’examen cytomorphologique, une analyse en cytométrie en flux permet la mise en évidence de cellules tumorales résiduelles. La présence systématique de CD158k à la surface des cellules de Sézary nous a conduit à rechercher l’expression d’autres KIRs. Sur les lymphocytes tumoraux circulants d’un patient ainsi que sur la lignée cellulaire correspondante, l’expression des formes activatrices et inhibitrices des récepteurs CD158a/h et CD158b/j est détectée. A la différence des lymphocytes NK et T CD8+, le récepteur présentant une fonction inhibitrice (KIR-L) ne l’emporte pas sur celui ayant une fonction activatrice (KIR-S) dans la cellule de Sézary. En fait, les KIR-L, à l’exception de CD158k, sont trouvés non fonctionnels dans la cellule tumorale. Ainsi, l’engagement des formes activatrices CD158h ou CD158j permet une régulation positive de la voie de signalisation CD3-dépendante de JNK et de la prolifération tumorale. Une étude fonctionnelle de la population T CD4+ KIR+, équivalent normal de la cellule de Sézary, a aussi été réalisée. Nous avons mis en évidence une expression préférentielle de la forme activatrice ou inhibitrice des récepteurs KIR homologues, selon le donneur. D’autre part, les KIRs activateurs ou inhibiteurs, exprimés à la surface des LT CD4+, jouent un rôle de co-récepteur vis-à-vis du TCR. Ainsi, une régulation positive ou négative de la prolifération et de la voie de signalisation CD3-dépendante de ERK est observée en fonction du type de récepteur co-engagé. Il est bien établi que les KIR-S s’associent à la molécule adaptatrice KARAP/DAP12 pour la transduction d’un signal d’activation. Dans les cellules T CD4+ saines et tumorales, la protéine recrutée par ces récepteurs est encore non identifiée. Notre étude sur la population T CD4+ CD158j+ de sujets sains montre l’implication de la protéine HS1 dans la signalisation mise en place par le récepteur KIR activateur. La réalisation de ce travail a permis de mieux comprendre les mécanismes mis en place à partir des KIRs dans les cellules T CD4+. Ce travail ouvre de nouvelles perspectives concernant le rôle de ces récepteurs dans les mécanismes permettant l'expansion tumorale des cellules de Sézary / Sézary syndrome (SS) is a leukemic and erythrodermic variant of cutaneous T-cell lymphomas. It is characterized by the presence of a clonal CD4+ T lymphocyte population in the skin, lymphnodes and peripheral blood. After clinical assessment, diagnosis of this disease is confirmed by immunohistochemistry analysis of a skin biopsy. However, the cytomorphology of circulating Sézary cells is not just associated to SS. Our laboratory has identified CD158k as a phenotypic marker for Sézary cells. This receptor can be used in the diagnosis of the SS and in monitoring the evolution of the disease. Our results show that the CD3/CD158k immunostaining, analysed by flow cytométrie, is more specific and sensitive than cytomorphology to detect atypical circulating cells. While more than 30% of the SS is misdiagnosed by the cytomorphologic identification, flow cytometry analysis allows the detection of residual tumor cells. Given the systemic expression of CD158k on Sézary cells, we next investigated the expression of additional KIRs. On circulating malignant lymphocytes from one patient and the corresponding cell line, the expression of inhibitory and activating forms of CD158a/h and CD158b/j receptors was detected. In contrast to NK cells and CD8+ T lymphocytes, the inhibitory receptor signaling (KIR-L) does not outweigh the activating receptor signaling (KIR-S) in the Sézary cell. In fact, KIR-L, except CD158k, are found not functional in the tumor cell. Thus, CD158h or CD158j engagement results in an enhanced CD3-induced cell proliferation and JNK activation. A functional study of CD4+ KIR+ T lymphocyte population, the normal equivalent of Sézary cells, was then performed. We observed an exclusive expression of the activating or the inhibitory form of KIR receptors, depending on the donor. Activating or inhibitory KIRs, expressed on the CD4+ T cell surface, act as coreceptors. Thus, a positive or negative regulation of the CD3-induced cell proliferation and ERK activation is observed by triggering the KIR-S or -L respectively. It is well known that stimulatory KIR initiates intracellular signals through their association with the adaptor protein KARAP/DAP12. However, in normal and malignant CD4+ T cells the protein recruited by these receptors is still not identified. Our study on CD4+ CD158j+ T lymphocyte population from healthy individuals showed the involvement of HS1 protein as a potential adaptor molecule in the activating KIR signaling pathway. This work has provided insight into the mechanisms of KIRs signaling in CD4+ T cells and opens new perspectives on the role of these receptors in proliferation of Sézary cells

Introduction:Acute Lymphoid Leukemia (ALL) is the most frequent cancer in young people and, if analyzed together with Non-Hodgkin Lymphoma (NHL), we find that they are responsible for at least one third of all cases of childhood cancer. Present-day therapeutic protocols include high doses of glucocorticoids (GC), drugs associate with high potential for elevating intraocular pressure (IOP) and, consequently provoking damage to the fibers of the optic nerve fibers, a pathology classified as cortisone glaucoma. In genetically susceptible patients, ocular hypertension normally occurs some weeks into the use of a steroid but is generally reversible with the suspension of its use. However, depending on the levels of ocular pressure and the duration of ocular hypertension, it can result in optic neuropathology and, in extreme cases, blindness. Since ALL and NHL are oncological disorders with elevated potential for cure of young people with have high life expectancy, the identification of eventual long-term treatment complications could give support to a delineation still lacking in scientific literature, that is, an ophthalmological protocol for these cases. Objective: The aim of this study was to evaluate the behavior of intraocular pressure in pediatric patients treated with GC for the acute lymphoproliferative neoplasias that are most common during childhood and adolescence.Methods: A systematic review of the theme was carried out, followed by a descriptive, prospective study of children and adolescents of both sexes who were diagnosed with ALL and NHL, and who were registered for beginning chemotherapeutic treatment at the Dr. Oswaldo Leite Oncology Center of Sergipe. The inclusion criteria were: diagnosis of ALL or NHL-T confirmed by immunophenotyping of bone marrow or peripheral blood samples (ALL), or immunohistochemistry of material obtained by open biopsy (NHL); age less than 19; no previous chemotherapy; absence of previous diagnosis compatible with glaucoma or any other disorder envolving change in intraocular pressure; no systemic use of GC in the six months preceding diagnosis of ALL or NHL. Patients whose evaluation of IOP might not have been technically adequate, as well as those who expired during the follow-up period, were excluded. Intraocular pressure was measured before treatment (D0), on the eighth (D8), the fourteenth (D14) and twentieth (D28) treatment day. The IOP results above 21 mm Hg were considered to be ocular hypertension. Results: Results of the systematic review indicate the need for new studies, for the review found a total of only three published articles whose results varied between total control of ocular pressure and visual function, to irreversible blindness. The results of our field research involved 15 patients, two of them with ocular hypertension, and with a statistically significant difference of measurements of IOP between D0 vs D8 and D0 vs D14 (p=0.013). Conclusion: The possibility of silent ocular hypertension, with the consequent risk of irreversible blindness, indicates the need to assess the introduction of a protocol for verification of IOP in patients recently diagnosed with ALL and NHL, including weekly exams, at least until the complete cessation of GC use. / Introdução: Leucemia Linfóide Aguda (ALL) é o câncer mais comumente encontrado entre os jovens e, se analisada em conjunto com o Linfoma não-Hodgkin (NHL), são responsáveis por pelo menos um terço dos casos de câncer infantil. Protocolos terapêuticos atuais incluem altas doses de glicocorticóides (GC), droga associada com alto potencial para elevar a pressão intraocular (IOP) e, consequentemente, provocar danos às fibras do nervo óptico, patologia classificada como glaucoma cortisônico. A hipertensão ocular geralmente ocorre com algumas semanas de uso de GC em pacientes geneticamente susceptíveis, mas é geralmente reversível com a descontinuação do tratamento. Entretanto, dependendo dos níveis pressóricos oculares e do tempo de elevação, pode resultar em neuropatia óptica e, em situações extremas, em cegueira. Por serem a ALL e o NHL doenças oncológicas com potencial elevado de cura, em indivíduos jovens com elevada expectativa de vida, a identificação de eventuais complicações de longo prazo decorrentes do tratamento poderá subsidiar o delineamento de um protocolo oftalmológico para esses casos, ainda inexistente na literatura científica. Objetivo: O objetivo deste estudo foi avaliar o comportamento da pressão intraocular em pacientes pediátricos portadores das mais frequentes neoplasias linfoproliferativas agudas da infância e adolescência, e que são tratados com GC. Métodos: Foi feita uma revisão sistemática sobre o tema estudado, seguida por um estudo descritivo, prospectivo, em crianças e adolescentes de ambos os sexos, com diagnóstico de ALL e NHL, matriculados para início de tratamento quimioterápico no Centro de Oncologia de Sergipe Dr. Oswaldo Leite. Os critérios de inclusão foram: diagnóstico de ALL ou NHL-T, confirmada por imunofenotipagem de amostra de medula óssea ou sangue periférico (ALL) ou imuno-histoquímica de material obtido por biópsia aberta (NHL); idade menor de 19 anos; sem quimioterapia anterior; ausência de diagnóstico prévio compatível com glaucoma ou doença anterior relacionada a qualquer mudança na pressão intra-ocular; não uso sistêmico de GC nos seis meses anteriores ao diagnóstico da ALL ou NHL. Pacientes cuja avaliação da pressão intraocular (PIO) pode não ter sido tecnicamente adequada e os que faleceram durante o período de seguimento foram excluídos. Realizaram-se medidas de pressão intraocular antes do tratamento (D0), no oitavo (D8), décimo quarto (D14) e vigésimo (D28) dias de tratamento. Os resultados da PIO acima de 21 mm de Hg foram considerados como hipertensão ocular Resultados: Os resultados da revisão sistemática apontaram para necessidade de novos estudos, limitando-se a um total de três publicações de relatos de casos envolvendo sete pacientes, com resultados variando de total controle da pressão ocular e conservação da função visual, até cegueira irreversível. Os resultados da pesquisa de campo envolveram 15 pacientes, com dois casos de hipertensão ocular e com diferença estatisticamente significativa entre as médias de PIO entre D0 vs D8 e D0 vs D14 (p = 0,013). Conclusão: A possibilidade de hipertensão ocular silenciosa, com o consequente risco de cegueira irreversível, indica a necessidade de se avaliar a introdução de um protocolo para verificação da IOP em pacientes jovens recentemente diagnosticados com ALL e NHL, incluindo exames semanais, pelo menos até a retirada completa do GC.