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Abstract Introduction/objectives Systemic lupus erythematosus (SLE) is a classic prototype of the multisystem autoimmune disease and follows a relapsing and remitting course. Triptolide is a diterpene triepoxide extracted from Chinese medicine Tripterygium wilfordii Hook F, with potent immunosuppressive and anti-inflammatory properties. Our previous work observed that triptolide alleviated lupus in MRL/lpr lupus mice with the upregulation of regulatory T cells (Treg) proportion in previous study. In this study, we explored the proportion of follicular T regulatory (Tfr), follicular T helper (Tfh) and germinal center (GC) B cells in lupus mice and evaluated the efficacy of triptolide for lupus treatment in vivo. Methods 20 female MRL/lpr mice were randomly divided into 2 treatment groups and treated orally with vehicle or triptolide. C3H mice were all housed as controlled group and treated orally with vehicle. The percentage of Tfr cells, Tfh cells and GC B cells in spleen of mice were detected by Flow cytometric analysis and immunohistochemistry after 13 weeks of treatment. Results We found that the percentage of Tfr cells decreased in MRL/lpr mice compared with controlled mice. The percentage of Tfh cells in MRL/lpr mice was significantly higher compared with that in controlled mice. The ratio of Tfr/Tfh is also decreased in lupus mice. After treated with triptolide in MRL/Lpr mice in vivo, the percentage of Tfr cells and ratio of Tfr/Tfh increased. The proportion of GC B cells also decreased in mice treated with triptolide by FACS and immunohistochemistry. Conclusions Our results demonstrate that the effect of triptolide in alleviating lupus is partly by reversing immune imbalance with increased percentage of Tfr cells and ratio of Tfr/Tfh. Triptolide might also has effect on immune response through inhibiting proliferating GC B cells.
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Systemic lupus erythematosus (SLE) mainly affects females at reproductive age, which has been associated with hormones, such as prolactin (PRL). Different studies suggest that PRL exacerbates the clinical manifestations of SLE both in patients and in mouse models (e.g., the MRL/lpr strain), increasing the production of autoantibodies, which can be deposited as immune complexes and trigger inflammation and damage to different tissues. The objective of this work was to explore the potential mechanisms by which PRL increases the concentration of self-reactive antibodies in the MRL/lpr SLE model. To this end, we determined the role of PRL on the activation and proliferation of germinal center B cells (B-GCs) and their differentiation into antibody-secreting cells (ASCs). We show that the absolute number and percentage of B-GCs were significantly increased by PRL in vivo or upon in vitro treatment with anti-IgM and anti-CD40 antibodies and PRL. The augmented B-GC numbers correlated with enhanced proliferation, but we did not observe enhanced expression of CD80 and CD86 activation markers or the BCL6 transcription factor, arguing against a more effective differentiation. Nevertheless, we observed enhanced phosphorylation of STAT1, secretion of IL-6, expression of IRF4, numbers of ASCs, and levels of IgG3 antibodies directed against dsDNA. Altogether, these results support the hypothesis that a PRL-mediated expansion of B-GCs yields more self-reactive ASCs, potentially explaining the pathogenic immune complexes that steadily lead to tissue damage during SLE.
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Autoanticorpos , Lúpus Eritematoso Sistêmico , Animais , Feminino , Camundongos , Complexo Antígeno-Anticorpo , Proliferação de Células , Centro Germinativo , Imunoglobulina G , Camundongos Endogâmicos MRL lpr , Plasmócitos , Prolactina/metabolismo , Linfócitos BRESUMO
Neonates have a limited adaptive response of plasma cells, germinal center (GC) B cells, and T follicular helper cells (TFH). As neonatal vaccination can be an important tool for AIDS prevention, these limitations need to be overcome. Chimeric DNA vaccine encoding p55Gag HIV-1 protein conjugated with lysosomal-associated membrane protein 1 (LAMP-1) has been described as immunogenic in the neonate period. Herein, we investigated the immunologic mechanisms involved in neonatal immunization with a LAMP-1/p55Gag (LAMP/Gag) DNA vaccine in a C57BL/6 mouse background. Neonatal LAMP/Gag vaccination induced strong Gag-specific T-cell response until adulthood and elevated levels of anti-Gag IgG antibodies. We also demonstrated for the first time that the immunogenicity of the neonatal period with LAMP/Gag is due to the induction of high-affinity anti-p24 IgG antibodies and long-term plasma cells. Together with that, there is the generation of early TFH cells and the formation of GC sites with the upregulation of activation-induced cytidine deaminase (AID) enzyme mRNA and protein expression in draining lymph nodes after neonatal LAMP/Gag vaccination. These findings underscore that the LAMP-1 strategy in the chimeric vaccine could be useful to enhance antibody production even in the face of neonatal immaturity, and they contribute to the development of new vaccine approaches for other emerging pathogens at an early stage of life.
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In this work, we evaluated recombinant receptor binding domain (RBD)-based vaccine formulation prototypes with potential for further clinical development. We assessed different formulations containing RBD plus alum, AddaS03, AddaVax, or the combination of alum and U-Omp19: a novel Brucella spp. protease inhibitor vaccine adjuvant. Results show that the vaccine formulation composed of U-Omp19 and alum as adjuvants has a better performance: it significantly increased mucosal and systemic neutralizing antibodies in comparison to antigen plus alum, AddaVax, or AddaS03. Antibodies induced with the formulation containing U-Omp19 and alum not only increased their neutralization capacity against the ancestral virus but also cross-neutralized alpha, lambda, and gamma variants with similar potency. Furthermore, the addition of U-Omp19 to alum vaccine formulation increased the frequency of RBD-specific geminal center B cells and plasmablasts. Additionally, U-Omp19+alum formulation induced RBD-specific Th1 and CD8+ T-cell responses in spleens and lungs. Finally, this vaccine formulation conferred protection against an intranasal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) challenge of K18-hACE2 mice.
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Adjuvantes Imunológicos/metabolismo , Linfócitos B/imunologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Brucella/metabolismo , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Centro Germinativo/imunologia , SARS-CoV-2/fisiologia , Compostos de Alúmen/metabolismo , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais , Formação de Anticorpos , Proteínas da Membrana Bacteriana Externa/imunologia , Brucella/imunologia , Resistência à Doença , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Glicoproteína da Espícula de Coronavírus/imunologiaRESUMO
The immune system plays a crucial role in cancer development either by fostering tumor growth or destroying tumor cells, which has open new avenues for cancer immunotherapy. It was only over the last decade that the role of B cells in controlling anti-tumor immune responses in the tumor milieu has begun to be appreciated. B and plasma cells can exert anti-tumor effects through antibody-dependent cell cytotoxicity (ADCC) and activation of the complement cascade, even though their effector functions extend beyond the classical humoral immunity. In tumor tissues, B cells can be found in lymphoid aggregates, known as tertiary lymphoid structures (TLSs), well-organized non-encapsulated structures composed of immune and stromal cells. These structures reflect a process of lymphoid neogenesis occurring in peripheral tissues upon long-lasting exposure to inflammatory signals. The TLS provides an area of intense B cell antigen presentation that can lead to optimal T cell activation and effector functions, as well as the generation of effector B cells, which can be further differentiated in either antibody-secreting plasma cells or memory B cells. Of clinical interest, the crosstalk between B cells and antigen-experienced and exhausted CD8+ T cells within mature TLS was recently associated with improved response to immune checkpoint blockade (ICB) in melanoma, sarcoma and lung cancer. Otherwise, B cells sparsely distributed in the tumor microenvironment or organized in immature TLSs were found to exert immune-regulatory functions, inhibiting anti-tumor immunity through the secretion of anti-inflammatory cytokines. Such phenotype might arise when B cells interact with malignant cells rather than T and dendritic cells. Differences in the spatial distribution likely underlie discrepancies between the role of B cells inferred from human samples or mouse models. Many fast-growing orthotopic tumors develop a malignant cell-rich bulk with reduced stroma and are devoid of TLSs, which highlights the importance of carefully selecting pre-clinical models. In summary, strategies that promote TLS formation in close proximity to tumor cells are likely to favor immunotherapy responses. Here, the cellular and molecular programs coordinating B cell development, activation and organization within TLSs will be reviewed, focusing on their translational relevance to cancer immunotherapy.
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Conventional dendritic cells (cDCs) are antigen-presenting cells specialized in naïve T cell priming. Mice splenic cDCs are classified as cDC1s and cDC2s, and their main functions have been elucidated in the last decade. While cDC1s are specialized in priming type 1 helper T cells (TH1) and in cross presentation, cDC2s prime T follicular helper (TFH) cells that stimulate germinal center (GC) formation, plasma cell differentiation and antibody production. However, less is known about the molecular mechanisms used by cDCs to prime those responses. Here, using WT and STAT6-deficient mice (STAT6 KO), we targeted a model antigen to cDC1s and cDC2s via DEC205 and DCIR2 receptors, respectively, in an attempt to study whether the STAT6 signaling pathway would modulate cDCs' ability to prime helper T cells. We show that the differentiation and maturation of cDCs, after stimulation with an adjuvant, were comparable between WT and STAT6 KO mice. Besides, our results indicate that, in STAT6 KO mice, antigen targeting to cDC2s induced reduced TFH and GC responses, but did not alter plasma cells numbers and antibody titers. Thus, we conclude that the STAT6 signaling pathway modulates the immune response after antigen targeting to cDC2s via the DCIR2 receptor: while STAT6 stimulates the development of TFH cells and GC formation, plasma cell differentiation occurs in a STAT6 independent manner.
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ABSTRACT Follicular helper T lymphocytes are a subpopulation of CD4+ T lymphocytes initially identified in germinal centers of follicles found in secondary lymphoid organs. The primary function of follicular helper T lymphocytes is to help B lymphocytes' antibody production. Changing of antibody class and affinity, B cell differentiation and memory generation depend on cooperation between follicular helper T lymphocytes and B cells. In blood, follicular helper T lymphocytes are called circulating follicular helper T lymphocytes. They are considered to have specificities similar to those developed in the secondary lymphoid organs. The phenotype of human follicular helper T lymphocytes is given by simultaneous expression of the markers CXCR5, Bcl-6, CD40L, PD-1, and ICOS. In germinal centers, follicular helper T lymphocytes synthesize interleukin 21 as predominant cytokine. In blood, subpopulations of circulating follicular helper T lymphocytes can be recognized, with different expressions of the classical follicular helper T lymphocytes markers and, in addition, can express other markers such as CXCR3 and CCR6. Presently, there is great interest in follicular helper T lymphocytes and circulating follicular helper T lymphocytes in vaccination studies as indicators of immunization efficacy. In addition, follicular helper T lymphocytes are investigated as possible markers of activity in many diseases and potential therapeutic intervention. This short review describes aspects of immunobiology and quantification of follicular helper T lymphocytes and circulating follicular helper T lymphocytes, and presents a few examples of related findings in systemic lupus erythematosus, rheumatoid arthritis, HIV infection and vaccination.
RESUMO Linfócitos T auxiliares foliculares são uma subpopulação de linfócitos T CD4+ identificada inicialmente nos centros germinativos dos folículos dos órgãos linfoides secundários. Sua função primordial é auxiliar os linfócitos B na produção de anticorpos. A mudança de classe e de afinidade dos anticorpos, a diferenciação das células B e a geração de memória dependem da cooperação entre os linfócitos T auxiliares foliculares e as células B. No sangue, recebem o nome de linfócitos T auxiliares circulantes. Considera-se que possuem especificidades semelhantes às desenvolvidas nos órgãos linfoides secundários. O fenótipo dos linfócitos T auxiliares humanos é dado pela expressão conjunta dos marcadores CXCR5, Bcl-6, CD40L, PD-1 e ICOS. Nos folículos, linfócitos T auxiliares sintetizam a interleucina 21 como citocina predominante. No sangue, são descritas várias subpopulações de linfócitos T auxiliares circulantes com expressões variadas dos marcadores clássicos de linfócitos T auxiliares, além de poderem agregar outros, como CXCR3 e CCR6. Existe um enorme interesse no estudo de linfócitos T auxiliares e linfócitos T auxiliares circulantes, para a avaliação de eficácia de vacinação. São também investigados como possíveis marcadores de atividade em muitas doenças e potenciais intervenções terapêuticas. Esta breve revisão descreve aspectos da imunobiologia e da quantificação de linfócitos T auxiliares humanos e linfócitos T auxiliares circulantes, além de apresentar alguns achados relacionados em lúpus eritematoso sistêmico, artrite reumatoide, infecção por HIV e vacinação.
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Humanos , Linfócitos T Auxiliares-Indutores/imunologia , Centro Germinativo/imunologia , Formação de Anticorpos , Linfócitos B/imunologiaRESUMO
B cell-activating factor (BAFF) is an essential cytokine in primary Sjögren's syndrome (pSS) physiopathology. It has been reported that pSS patients develop germinal center-like (GC-like) structures in their minor salivary glands (MSGs). BAFF, BAFF-R, TACI, and BCMA expression was analyzed in MSGs from 29 subjects (nonspecific chronic sialadenitis and focal lymphocytic sialadenitis with the presence [pSS-GC(+)] or absence [pSS-GC(-)] of GC-like structures). Twenty-four percent of patients showed ectopic GC-like structures and a high focus score [p < 0.001 vs pSS-GC(-)]. BAFF serum levels (sBAFF) were high in pSS patients (p = 0.025 vs healthy subjects). However, the pSS-GC(-) group showed higher sBAFF levels than pSS-GC(+) patients. BAFF and BAFF-R glandular expression levels were higher in pSS-GC(+) patients, without significant differences compared to pSS-GC(-) patients. Soluble levels of BAFF correlated with anti-La/SSB antibodies and disease duration. Our results showed that BAFF could contribute to focal lymphocytic infiltration. The role of BAFF-binding receptors in MSGs is proposed as a mechanism for the possible establishment of ectopic GC-like structures and disease progression in some patients. In conclusion, this study supports previous evidence that considers the active BAFF system role in the pathogenesis of pSS and the need for strong biomarkers in this disease.
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Fator Ativador de Células B/metabolismo , Receptor do Fator Ativador de Células B/metabolismo , Glândulas Salivares Menores/patologia , Síndrome de Sjogren/metabolismo , Adulto , Idoso , Fator Ativador de Células B/sangue , Antígeno de Maturação de Linfócitos B/metabolismo , Estudos de Casos e Controles , Feminino , Centro Germinativo/patologia , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Glândulas Salivares Menores/fisiologia , Índice de Gravidade de Doença , Síndrome de Sjogren/etiologia , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/patologia , Proteína Transmembrana Ativadora e Interagente do CAML/metabolismoRESUMO
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the activation of autoreactive T and B cells, autoantibody production, and immune complex deposition in various organs. Previous evidence showed abnormal accumulation of B cells in the thymus of lupus-prone mice, but the role of this population in the progression of the disease remains mostly undefined. Here we analyzed the spatial distribution, function, and properties of this thymic B cell population in the BWF1 murine model of SLE. We found that in diseased animals, thymic B cells proliferate, and cluster in structures that resemble ectopic germinal centers. Moreover, we detected antibody-secreting cells in the thymus of diseased-BWF1 mice that produce anti-dsDNA IgG autoantibodies. We also found that thymic B cells from diseased-BWF1 mice induced the differentiation of thymocytes to follicular helper T cells (TFH). These data suggest that the accumulation of B cells in the thymus of BWF1 mice results in the formation of germinal center-like structures and the expansion of a TFH population, which may, in turn, activate and differentiate B cells into autoreactive plasma cells. Therefore, the thymus emerges as an important niche that supports the maintenance of the pathogenic humoral response in the development of murine SLE.
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Linfócitos B/imunologia , Centro Germinativo/imunologia , Imunidade Humoral , Lúpus Eritematoso Sistêmico/imunologia , Células T Auxiliares Foliculares/imunologia , Timo/imunologia , Animais , Autoanticorpos/imunologia , Diferenciação Celular , Células Cultivadas , Técnicas de Cocultura , DNA/imunologia , Modelos Animais de Doenças , Feminino , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NZB , Plasmócitos/imunologiaRESUMO
In Argentina, Epstein-Barr virus (EBV) presence is associated with Hodgkin lymphoma (HL) in patients younger than 10 years, suggesting a relationship between low age of EBV infection and HL. Given that HL is derived from germinal centers (GC), our aim was to compare EBV protein expression and microenvironment markers between pediatric HL patients and EBV+GC in children. METHODS: EBV presence and immune cell markers were assessed by in situ hybridization and immunohistochemistry (IHC). RESULTS: Viral latency II pattern was proved in all HL patients and in 81.8% of EBV+ tonsillar GCs. LMP1 and LMP2 co-expression were proved in 45.7% HL cases, but only in 7.7% EBV+ GC in pediatric tonsils. An increase in CD4+, IL10, and CD68+ cells was observed in EBV+ GC. In pediatric HL patients, only the mean of IL10+ cells was statistically higher in EBV+ HL. CONCLUSIONS: Our findings point us out to suggest that LMP1 expression may be sufficient to drive neoplastic transformation, that an immune regulatory milieu counteracts cytotoxic environment in EBV-associated Hodgkin lymphoma, and that CD4+ and CD68+ cells may be recruited to act in a local collaborative way to restrict, at least in part, viral-mediated lymphomagenesis in tonsillar GC.
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Abstract Background: Diffuse large B-cell lymphoma (DLBCL) makes up from 25% to 40% of all non-Hodgkin lymphomas (NHL) and is the most common histological subtype worldwide. In Ecuador, DLBCL makes up 49% of all NHL cases, but there have been no studies on the immunophenotypic classificationof DLBCL in germinal center (GC) and non-germinal center (NGC)subtypes.This study was conducted to ascertain the immunophenotypic profile of DLBCL in an Ecuadorian hospital. Methods: A total of 38 DLBCL cases from 2006 to 2015 were compiled from the Pathology Service at Metropolitan Hospital (HM) in Quito, Ecuador. Eleven of these cases failed to meet the inclusion criteria; thus, the final sample consisted of 27 cases. Manual tissue microarrays were constructed, and three immunohistochemical markers (CD10, BCL6, and MUM1) were applied according to the Hans algorithm; in addition, the expression of the c-myc protein expression was also investigated. Results: The results showed that 77.8% of cases were of the GC subtype, 11.1% were NGC, and 11.1% were unclassifiable according to the Hans algorithm. Conclusions: The most frequent DLBCL subtype was GC, with 21 cases; and 40.7% of these cases overexpressed c-myc.
Resumen Antecedentes: El linfoma difuso de células grandes B (LDCGB) constituye el 25 al 40% del total de los linfomas no Hodgkin (LNH) y es el subtipo histológico más frecuente en el mundo. En Ecuador el LDCGB corresponde al 49% del total de los casos de LNH, sin embargo no hay estudios de clasificación inmunofenotípica del LDCGB en centro germinal (CG) y no centro germinal (NCG). Este estudio se realizó para conocer el perfil inmunofenotípico del LDCGB en un hospital de Ecuador. Métodos: Se recopiló del Servicio de Patología del Hospital Metropolitano de Quito, Ecuador, un total de 38 casos de LDCGB desde el 2006 al 2015, de los cuales 11 no cumplieron con los criterios de inclusión. La muestra final fue de 27 casos. Se realizaron microarreglos tisulares manuales para la aplicación de tres marcadores de inmunohistoquímica según el algoritmo de Hans (CD10, BCL6 y MUM1) y luego se correlacionó con la sobreexpresión de la proteína c-MYC. Resultados: El 77,8% de casos fue tipo CG, 11,1% fue NCG y 11,1% fueron inclasificables según Hans. Conclusiones: El subtipo de LDCGB más frecuente fue CG con 21 casos y de estos 40,7% sobreexpresaron c-MYC.
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Humanos , Linfoma de Células B , Equador , Proteína C , HospitaisRESUMO
PURPOSE: Despite considerable evidence that supports the NF-kB role in the immune system and lymphomagenesis, it is unclear whether specific NF-kB dimers control a particular set of genes that account for their biological functions. Our previous work showed that Hodgkin Lymphoma (HL) is unique, among germinal center (GC)-derived lymphomas, with respect to its dependency on Rel-B to survive. In contrast, diffuse large B-Cell lymphoma (DLBCL) including both Activated B-Cell-Like and Germinal Center B-Cell-Like, requires cREL and Rel-A to survive and it is not affected by Rel-B depletion. These findings highlighted the activity of specific NF-kB subunits in different GC-derived lymphomas. METHODS: Sequenced chromatin immunoprecipitated DNA fragments (ChIP-Seq) analysis revealed an extensive NF-kB DNA-binding network in DLBCL and HL. The ChIP-Seq data was merged with microarray analysis following the Rel-A, Rel-B or cRel knockdown to determine effectively regulated genes. RESULTS: Downstream target analysis showed enrichment for cell cycle control, among other signatures. Rel-B and cRel controlled different genes within the same signature in HL and DLBCL, respectively. BCL2 was exclusively controlled by Rel-B in HL. Both mRNA and protein levels decreased following Rel-B depletion meanwhile there was no change upon cRel knock-down. BCL2 exogenous expression partially rescued the death induced by decreased Rel-B in HL cells. CONCLUSION: The Rel-B hierarchical network defined HL and the cRel hierarchical network characterized DLBCL. Each Rel member performs specific functions in distinct GC-derived lymphomas. This result should be considered for the development of targeted therapies that are aimed to selectively inhibit individual NF-kB dimers.
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DNA de Neoplasias/metabolismo , Doença de Hodgkin/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , NF-kappa B/metabolismo , Apoptose/genética , Linfócitos B/metabolismo , Linfócitos B/patologia , Linhagem Celular Tumoral , DNA de Neoplasias/genética , Perfilação da Expressão Gênica , Células HEK293 , Doença de Hodgkin/genética , Humanos , Linfoma Difuso de Grandes Células B/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-rel/genética , Proteínas Proto-Oncogênicas c-rel/metabolismo , Transdução de Sinais , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Fator de Transcrição RelB/genética , Fator de Transcrição RelB/metabolismo , Transcrição GênicaRESUMO
CONTEXT AND OBJECTIVE: Gene expression and immunohistochemical profiling of diffuse large B-cell lymphoma (DLBCL) have revealed important prognostic subgroups: germinal center B-cell-like (GCB-like) DLBCL and activated B cell-like (ABC-like) DLBCL. Although few reports on high-risk DLBCL are available, the prognosis for the GCB-like subgroup has been shown to be better than that of the ABC-like subgroup. The role of Bcl-2 as a predictor of survival in DLBCL cases is unclear and its expression varies between the two subgroups of DLBCL. In this study, we analyzed the frequency and prognostic impact of Bcl-2 protein expression in high-risk DLBCL cases. DESIGN AND SETTING: Retrospective cohort study among DLBCL patients treated at Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP). METHODS: The prognostic impact of the expression of the proteins CD10, Bcl-6, MUM1 (multiple myeloma oncogene-1) and Bcl-2 on high-risk DLBCL cases was evaluated by means of immunohistochemistry. Seventy-three patients aged 18-60 years were evaluated for all these markers. RESULTS: Twenty-four cases (32.9 percent) were GCB-like and 49 (67.1 percent) were ABC-like, with no difference regarding complete remission, disease-free survival or overall survival rates. Twenty-seven patients (37 percent) showed Bcl-2 expression, which was the only independent factor predicting a worse prognosis for overall survival according to multivariate analysis. CONCLUSION: Bcl-2 protein was expressed in 37 percent of the high-risk DLBCL patients, without any difference between the ABC-like DLBCL and GCB-like DLBCL cases.
CONTEXTO E OBJETIVO: A expressão gênica e imunoistoquímica do linfoma difuso de grandes células B (LDGCB) vem permitindo a identificação de importantes subgrupos prognósticos: LDGCB do centro germinativo (CG) e LDGCB de células B ativadas (CBA). Entretanto, existem poucos dados disponíveis com LDGCB de alto risco, sendo o prognóstico dos LDGCB do CG melhor que os LDGCB de CBA. A participação do Bcl-2 como preditor de sobrevida nos LDGCB não é clara e sua expressão é variável entre os dois subgrupos de LDGCB. Neste estudo é avaliada a frequência e o prognóstico da expressão da proteína Bcl-2 em LDGCB de alto risco. TIPO DE ESTUDO E LOCAL: Estudo de coorte retrospectivo realizado entre portadores de LDGCB tratados no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. MÉTODOS: Foi avaliado o impacto prognóstico da expressão das proteínas CD10, Bcl-6, MUM1 (multiple myeloma oncogene-1) e Bcl-2 por imunoistoquímica em LDGCB de alto risco. Foram avaliados, para todos os marcadores, 73 pacientes com idade de 18 a 60 anos. RESULTADOS: Vinte e quatro (32,9 por cento) pacientes foram classificados como LDGCB do CG e 49 (67,1 por cento) como LDGCB de CBA, sem diferença nas taxas de remissão completa, sobrevida livre de doença e sobrevida global. Vinte e sete (37 por cento) apresentaram expressão de Bcl-2, o qual foi o único fator preditivo independente de pior prognóstico de sobrevida global à análise multivariada. CONCLUSÃO: A expressão da proteína Bcl-2 ocorreu em 37 por cento dos portadores de LDGCB de alto risco, sem diferença entre os subgrupos de LDGCB do CG ou de CBA.
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Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Linfoma Difuso de Grandes Células B/metabolismo , /metabolismo , Biomarcadores Tumorais/metabolismo , Distribuição de Qui-Quadrado , Estudos de Coortes , Proteínas de Ligação a DNA/metabolismo , Intervalo Livre de Doença , Expressão Gênica , Centro Germinativo/metabolismo , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/genética , Proteínas do Mieloma/metabolismo , Neprilisina/metabolismo , Prognóstico , Estudos Retrospectivos , Adulto JovemRESUMO
INTRODUÇÃO: Os linfomas B atualmente podem ser agrupados de acordo semelhanças moleculares e imunoistoquímicas com o linfócito do centro germinativo (CG) ou linfócito ativado (LA/pós CG), sendo este de pior prognóstico. O objetivo deste trabalho foi analisar a expressão de CD10, BCL-6 e MUM1 em pacientes portadores de LBPM e correlacionar com prognóstico. MÉTODOS: análise retrospectiva das variáveis clínicas e de tratamento de 44 pacientes portadores de LBPM. Estudo imunoistoquímico de CD10, BCL-6 e MUM1 em 29 pacientes com material disponível. RESULTADOS: idade mediana foi de 28 anos e 70% eram do sexo feminino. A positividade para CD10, BCL-6 e MUM1 foi de: 24%, 65% e 58%. De acordo com o modelo de Hans, 38% foi classificado como CG e 62% como pós CG. A sobrevida global em 5 anos e sobrevida livre de doença foi de 47% e 81%, respectivamente. Resposta Completa após quimioterapia de primeira linha (p=0,0001), radioterapia de mediastino (p=0,004) e IPI (0,039) tiveram associação com a sobrevida. A positividade para MUM1 esteve associado a pior sobrevida global (p=0,014). Aplicando o modelo de Hans não foi observada nenhuma associação com sobrevida. Na análise multivariada apenas Resposta (RR 4,28 (IC 95% 1,3-13,6) e MUM1 (RR 3,54 (1,1-11,5) correlacionaram com a sobrevida. CONCLUSÃO: Para este grupo de pacientes com características clínicas homogêneas, resposta completa e expressão de MUM1 estiveram associados à sobrevida. A classificação deste linfoma em CG e pós-CG utilizando CD10, BCL-6 e MUM1 não se correlacionou com evolução. Estudos futuros com casuística maior são necessários para melhor definir os fatores prognósticos do LBPM.
INTRODUCTION: Primary Mediastinal Large B Cell Lymphoma (PMLBCL) is a distinct clinico-pathologic entity that differs from other Diffuse Large B Cell Lymphomas (DLBCL). Classification of DLBCL in GC and post-GC according can identify two subgroups of lymphomas with distinct prognosis. The aim of this study is to analyze the expression of CD10, BCL-6 and MUM1 in PMLBCL and correlate with prognosis. METHODS: retrospective analysis of clinical variables of 44 patients with PMLBCL and expression of CD10, BCL- 6 and MUM1 in 29 patients with available tissue. RESULTS: median age was 28 years and 70% of the patients were female. CD10, BCL-6 and MUM1 was positive in 24%, 65% and 58%, respectively. According to Hans classification, 38% were classified as GC and 62% as post-GC. Five year OS and DFS was 47% and 81%, respectively. In univariate analysis Complete Response (p=0.0001), Radiation therapy (p=0.004), IPI (0.039), and MUM1 expression (0.014) correlated with OS. No correlation was seen with Hans classification and survival. CONCLUSION: for this group of patients with homogeneous clinical features, response to therapy and MUM1 expression were associated with prognosis. The Hans algorithm proposed for aggressive lymphomas was not a predictive tool for survival in PMLBCL. Further studies are necessary to validate our finding and identify better prognostic variable for PMLBCL.