Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
PLoS One ; 18(8): e0285917, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37647315

RESUMO

BACKGROUND: Interferon-y Release Assays (IGRA) reversions have been reported in different clinical scenarios for the diagnosis of tuberculosis (TB) infection. This study aimed to determine the rate of QuantiFERON-TB Gold Plus (QFT-Plus) reversions during contact investigation as a potential strategy to reduce the number of preventive treatments. METHODS: Prospective, multicentre cohort study of immunocompetent adult contacts of patients with pulmonary TB tested with QFT-Plus. Contacts with an initial positive QFT-Plus (QFT-i) underwent a second test within 4 weeks (QFT-1), and if negative, underwent a repeat test 4 weeks later (QFT-2). Based on the QFT-2 result, we classified cases as sustained reversion if they remained negative and as temporary reversion if they turned positive. RESULTS: We included 415 contacts, of whom 96 (23.1%) had an initial positive test (QFT-i). Following this, 10 had negative QFT-1 results and 4 (4.2%) of these persisted with a negative result in the QFT-2 (sustained reversions). All four sustained reversions occurred in contacts with IFN-γ concentrations between ≥0.35 and ≤0.99 IU•mL-1 in one or both QFT-i tubes. CONCLUSION: In this study, TB contact investigations rarely reveal QFT-Plus reversion. These results do not support retesting cases with an initial positive result to reduce the number of preventive treatments.


Assuntos
Tuberculose Latente , Tuberculose Pulmonar , Tuberculose , Adulto , Humanos , Estudos de Coortes , Estudos Prospectivos , Tuberculose/diagnóstico , Tuberculose Pulmonar/diagnóstico
2.
Leuk Res ; 132: 107347, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37356281

RESUMO

Allogeneic hematopoietic stem cell transplant (HCT) recipients are at high risk of severe COVID-19 despite vaccination. Little is known about cellular response to SARS-CoV-2 vaccine in this population, especially in recently transplanted patients (RTP). In this single-center study we examined cellular and humoral response to the mRNA-1273 (Spikevax®) vaccine in recently transplanted patients (RTP, n = 49), and compared them to long-term transplanted patients (LTTP, n = 19) and healthy controls (n = 20) at three different timepoints: one and three months after the second dose (T1 and T2, respectively, 28 days apart), and one month after the third dose (T3). Controls did not receive a third dose. RTPs showed lower IgG anti-S1 titers than healthy controls at both T1 (mean 0.50 vs 0.94 arbitrary units -AU-, p < 0.0001) and T2 (0.37 vs 0.79 AU, p < 0.0001). They also presented lower titers than LTTPs at T1 (0.50 vs 0.66, p = 0.01), but no differences at T2 (0.37 vs 0.40 AU, p = 0.55). The rate of positive T-cell responses was lower in RTPs than in controls at both T1 and T2 (61.2 % vs 95 %, p = 0.007; 59.2 % vs 100 %, p = 0.001, respectively), but without statistically significant differences between transplanted groups. At T3 no differences were seen between RTPs and LTTPs as well, neither in IgG antibodies (p = 0.82) nor in cellular responses (p = 0.15), although a third dose increased the rate of positive cellular and humoral responses in approximately 50 % of recently transplanted patients. However, active immunosuppressive treatment severely diminished their chances to produce an adequate response.


Assuntos
COVID-19 , Transplante de Células-Tronco Hematopoéticas , Vacinas , Humanos , Transplantados , Vacina de mRNA-1273 contra 2019-nCoV , Vacinas contra COVID-19 , Imunidade Humoral , COVID-19/prevenção & controle , SARS-CoV-2 , Imunoglobulina G
3.
Brain Commun ; 5(2): fcad109, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37091585

RESUMO

Multiple sclerosis is a tissue-specific autoimmune disease of the central nervous system in which the antigen(s) remains elusive. Antibodies targeting the flotillin-1/2 complex have been described in 1-2% of the patients in a recent study. Other candidate antigens as anoctamin-2 or neurofascin-155 have been previously described in multiple sclerosis patients, although their clinical relevance remains uncertain. Our study aims to analyse the frequency and clinical relevance of antibodies against neurofascin-155, anoctamin-2 and flotillin-1/2 complex in multiple sclerosis. Serum (n = 252) and CSF (n = 50) samples from 282 multiple sclerosis patients were included in the study. The control group was composed of 260 serum samples (71 healthy donors and 189 with other neuroinflammatory disorders). Anti-flotillin-1/2, anti-anoctamin-2 and anti-neurofascin-155 antibodies were tested by cell-based assays using transfected cells. We identified six multiple sclerosis patients with antibodies against the flotillin-1/2 complex (2.1%) and one multiple sclerosis patient with antibodies against anoctamin-2 (0.35%). All multiple sclerosis patients were negative for anti-neurofascin-155 antibodies. Three of the anti-flotillin-1/2 positive patients showed anti-flotillin-1/2 positivity in other serum samples extracted at different moments of their disease. Immunoglobulin G subclasses of anti-flotillin-1/2 antibodies were predominantly one and three. We confirm that antibodies targeting the flotillin-1/2 complex are present in a subgroup of patients with multiple sclerosis. Further studies are needed to understand the clinical and pathological relevance of anti-flotillin-1/2 autoantibodies in multiple sclerosis.

4.
Sci Rep ; 12(1): 20698, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36450745

RESUMO

Non-absorbable polypropylene (PP) meshes have been widely used in surgical reconstruction of the pelvic floor disorders. However, they are associated with serious complications. Human acellular dermal matrices (hADM) have demonstrated safety and efficacy in reconstructive medicine, but their suitability and efficacy at vaginal level is not known. This study compares the biological performance of PP mesh and a newly developed hADM. 20 rabbits were randomized to receive the hADM graft or the PP mesh. Grafts were surgically implanted in the abdominal wall and vagina. After 180 days, grafts were explanted and evaluated. The vaginal mesh extrusion rate was higher in the PP group (33% vs. 0%, p = 0.015). Full integration of the vaginal grafts was more frequent in the hADM group, where 35% of the grafts were difficult to recognize. In the PP group, the vaginal mesh was identified in 100% of the animals (p = 0.014). In PP group, the infiltrates had a focal distribution and were mostly located in the internal part of the epithelium, while in the hADM group, the infiltrates had a diffuse distribution. Additionally, the hADM group also presented more B-lymphocytes and less T-lymphocytes. Biomechanical analysis showed that hADM had lower resistance to stress. Moreover, PP mesh stiffness and elasticity were higher. Then, hADM is associated with fewer clinical complications, as well as better tissue integration. However, it shows greater incorporation into the surrounding native tissue, especially in the vaginal location, undergoing a reduction in its biomechanical properties 6 months after implantation.


Assuntos
Derme Acelular , Lagomorpha , Procedimentos de Cirurgia Plástica , Animais , Feminino , Coelhos , Humanos , Polipropilenos , Diafragma da Pelve/cirurgia , Telas Cirúrgicas/efeitos adversos
5.
Neuromuscul Disord ; 32(8): 664-671, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35811274

RESUMO

The aim of this study is to evaluate the long-term efficacy, safety, and impact on immunoglobulin G (IgG) levels of rituximab in patients with myasthenia gravis (MG). A retrospective, observational study of drug-refractory MG patients treated with rituximab was done. The MG Foundation of America postintervention status (MGFA-PIS) was used to evaluate clinical response. Serum IgG levels were determined at baseline and post-treatment. Hypogammaglobulinemia was defined as IgG<7g/L. Thirty patients were included, 12 with anti-MuSK and 18 with anti-AChR antibodies. Mean (SD) follow-up was 85.5 (48) months. All 12 MuSK+ patients but only six (33%) AChR+ patients achieved minimal manifestations or remission (p<0.01). Nine severe infections were observed in five patients (17%). One patient was diagnosed with progressive multifocal leukoencephalopathy. At baseline, two patients (2/24; 8%) had hypogammaglobulinemia. During follow-up, hypogammaglobulinemia was observed in 60% (3/5) of patients who developed an infection and in 33% (7/21) who did not. Two of these patients died of infection-related complications. This study supports the effectiveness of rituximab in patients with MG, especially those with anti-MuSK antibodies. Severe infections may appear after rituximab treatment and hypogammaglobulinemia might play a role on it. A standard protocol would be needed to closely monitor IgG levels in MG patients treated with rituximab.


Assuntos
Agamaglobulinemia , Miastenia Gravis , Agamaglobulinemia/induzido quimicamente , Agamaglobulinemia/tratamento farmacológico , Humanos , Imunoglobulina G/uso terapêutico , Fatores Imunológicos/efeitos adversos , Receptores Colinérgicos , Estudos Retrospectivos , Rituximab/efeitos adversos
6.
Front Immunol ; 13: 904686, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35833134

RESUMO

Two years after the appearance of the SARS-CoV-2 virus, the causal agent of the current global pandemic, it is time to analyze the evolution of the immune protection that infection and vaccination provide. Cellular immunity plays an important role in limiting disease severity and the resolution of infection. The early appearance, breadth and magnitude of SARS-CoV-2 specific T cell response has been correlated with disease severity and it has been thought that T cell responses may be sufficient to clear infection with minimal disease in COVID-19 patients with X-linked or autosomal recessive agammaglobulinemia. However, our knowledge of the phenotypic and functional diversity of CD8+ cytotoxic lymphocytes, CD4+ T helper cells, mucosal-associated invariant T (MAIT) cells and CD4+ T follicular helper (Tfh), which play a critical role in infection control as well as long-term protection, is still evolving. It has been described how CD8+ cytotoxic lymphocytes interrupt viral replication by secreting antiviral cytokines (IFN-γ and TNF-α) and directly killing infected cells, negatively correlating with stages of disease progression. In addition, CD4+ T helper cells have been reported to be key pieces, leading, coordinating and ultimately regulating antiviral immunity. For instance, in some more severe COVID-19 cases a dysregulated CD4+ T cell signature may contribute to the greater production of pro-inflammatory cytokines responsible for pathogenic inflammation. Here we discuss how cellular immunity is the axis around which the rest of the immune system components revolve, since it orchestrates and leads antiviral response by regulating the inflammatory cascade and, as a consequence, the innate immune system, as well as promoting a correct humoral response through CD4+ Tfh cells. This review also analyses the critical role of cellular immunity in modulating the development of high-affinity neutralizing antibodies and germinal center B cell differentiation in memory and long-lived antibody secreting cells. Finally, since there is currently a high percentage of vaccinated population and, in some cases, vaccine booster doses are even being administered in certain countries, we have also summarized newer approaches to long-lasting protective immunity and the cross-protection of cellular immune response against SARS-CoV-2.


Assuntos
COVID-19 , Antivirais , Citocinas , Humanos , Imunidade Celular , SARS-CoV-2
7.
Artigo em Inglês | MEDLINE | ID: mdl-35728947

RESUMO

BACKGROUND AND OBJECTIVES: Evidence regarding the safety and efficacy of messenger RNA (mRNA) vaccines in patients with myasthenia gravis (MG) after immunosuppressive therapies is scarce. Our aim is to determine whether the mRNA-1273 vaccine is safe and able to induce humoral and cellular responses in patients with MG. METHODS: We performed an observational, longitudinal, prospective study including 100 patients with MG of a referral center for MG in our country, conducted from April 2021 to November 2021 during the vaccination campaign. The mRNA-1273 vaccine was scheduled for all participants. Blood samples were collected before vaccination and 3 months after a second dose. Clinical changes in MG were measured using the MG activities of daily life score at baseline and 1 week after the first and second doses. A surveillance of all symptoms of coronavirus disease 2019 (COVID-19) was conducted throughout the study. Humoral and cellular immune responses after vaccination were assessed using a spike-antibody ELISA and interferon gamma release assay in plasma. The primary outcomes were clinically significant changes in MG symptoms after vaccination, adverse events (AEs), and seroconversion and T-cell immune response rates. RESULTS: Ninety-nine patients completed the full vaccination schedule, and 98 had 2 blood samples taken. A statistically significant worsening of symptoms was identified after the first and second doses of the mRNA-1273 vaccine, but this was not clinically relevant. Mild AEs occurred in 14 patients after the first dose and in 21 patients after the second dose. Eighty-seven patients developed a humoral response and 72 patients showed a T-cell response after vaccination. A combined therapy with prednisone and other immunosuppressive drugs correlated with a lower seroconversion ratio (OR = 5.97, 95% CI 1.46-24.09, p = 0.015) and a lower T-cell response ratio (OR = 2.83, 95% CI 1.13-7.13, p = 0.024). DISCUSSION: Our findings indicate that the mRNA vaccination against COVID-19 is safe in patients with MG and show no negative impact on the disease course. Patients achieved high humoral and cellular immune response levels. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that patients with MG receiving the mRNA-1273 vaccine did not show clinical worsening after vaccination and that most of the patients achieved high cellular or immune response levels.


Assuntos
Vacina de mRNA-1273 contra 2019-nCoV , COVID-19 , Miastenia Gravis , Vacina de mRNA-1273 contra 2019-nCoV/efeitos adversos , Vacina de mRNA-1273 contra 2019-nCoV/imunologia , Anticorpos Antivirais/sangue , COVID-19/prevenção & controle , Humanos , Imunidade Celular , Imunidade Humoral , Estudos Longitudinais , Miastenia Gravis/complicações , Estudos Prospectivos , SARS-CoV-2 , Linfócitos T/imunologia
8.
Microbiol Spectr ; 9(3): e0097221, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34756079

RESUMO

We investigated whether the difference of antigen tube 2 (TB2) minus antigen tube 1 (TB1) (TB2-TB1) of the QuantiFERON-TB gold plus test, which has been postulated as a surrogate for the CD8+ T-cell response, could be useful in identifying recent tuberculosis (TB) exposure. We looked at the interferon gamma (IFN-γ) responses and differences in TB2 and TB1 tubes for 686 adults with QFT-plus positive test results. These results were compared among groups with high (368 TB contacts), low (229 patients with immune-mediated inflammatory diseases [IMID]), and indeterminate (89 asylum seekers or people from abroad [ASPFA]) risks of recent TB exposure. A TB2-TB1 value >0.6 IU·ml-1 was deemed to indicate a true difference between tubes. In the whole cohort, 13.6%, 10.9%, and 11.2% of cases had a TB2>TB1 result in the contact, IMID, and ASPFA groups, respectively (P = 0.591). The adjusted odds ratios (aORs) for an association between a TB2-TB1 result of >0.6 IU·ml-1 and risk of recent exposure versus contacts were 0.71 (95% confidence interval [CI], 0.31 to 1.61) for the IMID group and 0.86 (95% CI, 0.49 to 1.52) for the ASPFA group. In TB contact subgroups, 11.4%, 15.4%, and 17.7% with close, frequent, and sporadic contact had a TB2>TB1 result (P = 0.362). The aORs versus the close subgroup were 1.29 (95% CI, 0.63 to 2.62) for the frequent subgroup and 1.55 (95% CI, 0.67 to 3.60) for the sporadic subgroup. A TB2-TB1 difference of >0.6 IU·ml-1 was not associated with increased risk of recent TB exposure, which puts into question the clinical potential as a proxy marker for recently acquired TB infection. IMPORTANCE Contact tuberculosis tracing is essential to identify recently infected people, who therefore merit preventive treatment. However, there are no diagnostic tests that can determine whether the infection is a result of a recent exposure or not. It has been suggested that by using the QuantiFERON-TB gold plus, an interferon gamma (IFN-γ) release assay, a difference in IFN-γ production between the two antigen tubes (TB2 minus TB1) of >0.6 IU·ml-1 could serve as a proxy marker for recent infection. In this large multinational study, infected individuals could not be classified according to the risk of recent exposure based on differences in IFN-γ in TB1 and TB2 tubes that were higher than 0.6 IU·ml-1. QuantiFERON-TB gold plus is not able to distinguish between recent and remotely acquired tuberculosis infection, and it should not be used for that purpose in contact tuberculosis tracing.


Assuntos
Busca de Comunicante/métodos , Testes de Liberação de Interferon-gama/métodos , Interferon gama/imunologia , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/imunologia , Adulto , Idoso , Antígenos de Bactérias/imunologia , Linfócitos T CD8-Positivos/imunologia , Exposição Ambiental/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Sensibilidade e Especificidade , Tuberculose/diagnóstico
9.
Ann Hematol ; 100(12): 2997-3005, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34463804

RESUMO

Smoldering multiple myeloma (SMM) is an asymptomatic and biologically heterogeneous plasma cell disorder, with a highly variable clinical course. Immunoparesis, defined by total immunoglobulin measurements, has been shown to be an independent risk factor for progression to symptomatic disease. The heavy/light chain (HLC) assay allows precise measurement of the polyclonal immunoglobulin of the same isotype, enabling the evaluation of isotype-matched immunoparesis (IMI). In this study, we prospectively characterized immunoparesis, as determined by HLC measurements, in 53 SMM patients. Severe IMI was present in 51% of patients, while severe IP of uninvolved isotypes (HLC IP) was present in 39%. Most of the patients with severe HLC IP presented with severe IMI, but not the other way around. Isotype specificity of immune suppression was suggested by lower relative values of isotype-matched HLC pairs, both for IgG and IgA SMM. Severe IMI was associated with other risk factors for progression while patients with severe IMI and severe HLC IP showed an even higher risk profile. Both severe IMI and severe IgM HLC IP showed a significantly shorter time to progression. Finally, gene expression analysis demonstrated differences in the bone marrow microenvironment between patients with IMI and IMI plus HLC IP, with an increased expression of genes associated with cytolytic cells. In conclusion, our data supports isotype specificity of early immunoglobulin suppression mechanisms. While suppression of both involved and uninvolved isotypes is associated with risk of progression, the later appears to develop with more advanced disease and could be mediated by different mechanisms.


Assuntos
Cadeias Pesadas de Imunoglobulinas/sangue , Cadeias Leves de Imunoglobulina/sangue , Mieloma Múltiplo Latente/sangue , Idoso , Feminino , Seguimentos , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
12.
J Invest Dermatol ; 140(6): 1176-1183, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31778714

RESUMO

Psoriasis is currently considered to be an immune-mediated disease whose patho-mechanisms involve platelet activation, which seems to correlate with the activity of the disease. Platelet activation is associated with the formation of platelet-lymphocyte complexes (PLyC), although their significance remains unknown. Moreover, biological treatments that target tumor necrosis factor-α (TNF-α) reduce platelet activation. To clarify the significance of PLyC, we compared their levels in patients with psoriasis with those of healthy donors and determined whether platelet binding modifies the secretion of IL-17A by T helper cells. Finally, we assessed the effect of anti-TNF-α treatment on PLyC in responder and non-responder patients with psoriasis. Ours results demonstrated an increase in PLyC in patients with psoriasis. Moreover, the percentage of IL-17-secreting cells was observed to be higher in the platelet-lymphocyte complex population, and these cells tended to secrete greater amounts of IL-17A. Psoriasis patients treated with anti-TNF-α normalized platelet-lymphocyte complex values, and the basal percentage of platelet-T helper lymphocyte complexes was significantly higher in the responder group. In conclusion, PLyC are increased in psoriasis patients, and the number of complexes decreases in response to anti-TNF-α treatment, specifically in the responder group of patients. This finding suggests that PLyC are a prognostic biomarker of response to anti-TNF-α therapy, but prospective studies are necessary to verify these results in patients with psoriasis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Plaquetas/imunologia , Psoríase/tratamento farmacológico , Linfócitos T Auxiliares-Indutores/imunologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/farmacologia , Adalimumab/uso terapêutico , Adulto , Anti-Inflamatórios/farmacologia , Plaquetas/metabolismo , Feminino , Humanos , Interleucina-17/metabolismo , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Prognóstico , Psoríase/sangue , Psoríase/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Resultado do Tratamento , Fator de Necrose Tumoral alfa/metabolismo
13.
Sci Rep ; 9(1): 6155, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992531

RESUMO

Antibodies against myelin-associated glycoprotein (MAG) almost invariably appear in the context of an IgM monoclonal gammopathy associated neuropathy. Very few cases of anti-MAG neuropathy lacking IgM-monoclonal gammopathy have been reported. We investigated the presence of anti-MAG antibodies in 69 patients fulfilling diagnostic criteria for CIDP. Anti-MAG antibodies were tested by ELISA and confirmed by immunohistochemistry. We identified four (5.8%) anti-MAG positive patients without detectable IgM-monoclonal gammopathy. In two of them, IgM-monoclonal gammopathy was detected at 3 and 4-year follow-up coinciding with an increase in anti-MAG antibodies titers. In conclusion, anti-MAG antibody testing should be considered in chronic demyelinating neuropathies, even if IgM-monoclonal gammopathy is not detectable.


Assuntos
Autoanticorpos/imunologia , Imunoglobulina M/imunologia , Glicoproteína Associada a Mielina/imunologia , Paraproteinemias/imunologia , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/imunologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Paraproteinemias/diagnóstico , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/diagnóstico
15.
Clin Chim Acta ; 488: 135-142, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30408481

RESUMO

BACKGROUND AND OBJECTIVES: Percentages of blood CD19+CD5+ B cells and CD8+perforin+ T lymphocytes can predict response to Interferon (IFN)-beta treatment in relapsing-remitting multiple sclerosis (RRMS) patients. We aimed to standardize their detection in a multicenter study, prior to their implementation in clinical practice. METHODS: Fourteen hospitals participated in the study. A reference centre was established for comparison studies. Peripheral blood cells of 105 untreated RRMS patients were studied. Every sample was analyzed in duplicate in the participating centre and in the reference one by flow cytometry. When needed, participating centres corrected fluorescence compensations and negative cut-off position following reference centre suggestions. Concordance between results obtained by participating centres and by reference one was evaluated by intraclass correlation coefficients (ICC) and Spearman correlation test. Centre performance was measured by using z-scores values. RESULTS: After results review and corrective actions implementation, overall ICC was 0.86 (CI: 0.81-0.91) for CD19+CD5+ B cell and 0.89 (CI: 0.85-0.93) for CD8+ perforin+ T cell quantification; Spearman r was 0.92 (0.89-0.95; p <0.0001) and 0.92 (0.88-0.95; p <0.0001) respectively. All centres obtained z-scores≤0.5 for both biomarkers. CONCLUSION: Homogenous percentages of CD19+CD5+ B cells and CD8 perforin+ T lymphocytes can be obtained if suitable compensation values and negative cut-off are pre-established.


Assuntos
Citometria de Fluxo , Interferon beta/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Esclerose Múltipla/sangue
17.
Exp Hematol ; 39(11): 1064-71, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21864486

RESUMO

Chemoimmunotherapy with anti-CD20 monoclonal antibody rituximab is increasingly used for the treatment of patients with chronic lymphocytic leukemia (CLL). Antibody-dependent cytotoxicity (ADCC) is one of the most important mechanisms of action of rituximab against B-cell malignancies. We studied ways to increase the cytotoxic effect of rituximab on CLL cells by enhancing ADCC. Peripheral blood mononuclear cell (PBMC) or purified natural killer (NK) cells from healthy donors were activated with interleukin-15 (IL-15) and cultured with rituximab-coated CLL cells, and ADCC was evaluated using a (51)chromium release assay. The IL-15 significantly enhanced in vitro ADCC against CLL cells, and this effect was mainly mediated by NK cells. The IL-15 treated effector cells with the low affinity FcγRIIIA receptor (158FF) had an ADCC comparable to those with the high affinity FcγRIIIA form (158VF). In addition, IL-15 enhanced rituximab-mediated ADCC of CLL cells in the presence of transforming growth factor-beta. The IL-15 increases rituximab-mediated ADCC against CLL, and supports the use of such agents with the goal of improving clinical response to chemoimmunotherapy in patients with CLL.


Assuntos
Anticorpos Monoclonais Murinos/farmacologia , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Terapia de Imunossupressão , Interleucina-15/farmacologia , Leucemia Linfocítica Crônica de Células B/patologia , Fator de Crescimento Transformador beta/farmacologia , Antineoplásicos , Citotoxinas , Antagonismo de Drogas , Humanos , Imunossupressores , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Rituximab , Fator de Crescimento Transformador beta/imunologia , Células Tumorais Cultivadas
19.
Inflamm Bowel Dis ; 15(11): 1686-96, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19572373

RESUMO

BACKGROUND: Pathogen infection is a complex process in which several pathogen-recognition receptor (PRR) pathways are activated to induce proinflammatory mediators. The activation of multiple PRRs suggests an interaction between Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain-like receptor (NOD) signaling pathways. METHODS: To understand the modulation induced by NOD2 signals on successive responses to pathogen-associated molecular patterns (PAMPs), we examined how muramyl dipeptide (MDP) pretreatment reprograms the MDP+LPS (lipopolysaccharide) response of monocytes from human peripheral blood. RESULTS: Preexposure to bacterial MDP components induced selective tolerance to a subsequent NOD2+TLR4 stimulation. MDP pretreatment inhibited the production of tumor necrosis factor alpha (TNFalpha) and interleuken 10 (IL10), whereas IL6 and IL8 remained unaffected. MDP-induced tolerance was independent of receptor downregulation but was associated with reduced levels of phosphorylated TAK1 and abrogated phosphorylation of the downstream MAPK.Since Nod2 mutations have been associated with susceptibility to develop Crohn's disease (CD), we compared the MDP-induced tolerance in healthy donors and CD patients with compound heterozygous Nod2 mutations (Mut-Nod2) expressing variant NOD2 proteins. MDP-induced tolerance in Mut-Nod2 patients reduced IL10 but not TNFalpha production. In contrast with healthy donors, a p38-independent TNFalpha production was observed during the kinetics of the MDP+LPS response in Mut-Nod2 patients. CONCLUSIONS: Our findings suggest that the selective tolerance induced by MDP in healthy donors was related to the modulation of a convergent nub of NOD2 and TLR4 signaling pathways. This MDP-induced tolerance was impaired in Mut-Nod2 CD patients, resulting in a p38-independent TNFalpha production and an imbalance between pro- and antiinflammatory cytokines that could be partly responsible for the pathogenesis of CD.


Assuntos
Doença de Crohn/imunologia , Tolerância Imunológica/imunologia , Monócitos/imunologia , Proteína Adaptadora de Sinalização NOD2/genética , Receptor 4 Toll-Like/metabolismo , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Adjuvantes Imunológicos/farmacologia , Doença de Crohn/genética , Citometria de Fluxo , Humanos , Tolerância Imunológica/efeitos dos fármacos , Imunofenotipagem , Técnicas In Vitro , Interleucina-10/metabolismo , Ligantes , Lipopolissacarídeos/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Monócitos/citologia , Monócitos/efeitos dos fármacos , NF-kappa B/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Mutação Puntual , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Histopathology ; 54(4): 478-85, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19309400

RESUMO

AIMS: In T cells, protein kinase C (PKC) theta plays a major role in T-cell receptor (TCR)-mediated activation of a novel nuclear factor (NF)-kappaB pathway that involves phosphorylation of p65 at serine 536 (Pp65(Ser536)). Bcl-10 acts along the same pathway downstream of PKC theta to activate NF-kappaB. The aim was to investigate the relationship between the expression of PKC theta, Bcl-10 and P-p65(Ser536) proteins and their prognostic significance in peripheral T-cell lymphomas (PTCLs). METHODS AND RESULTS: Paraffin-embedded tissues from 30 patients with PTCLs treated with curative intention were evaluated retrospectively. Expression of PKC theta, Bcl-10 and P-p65(Ser536) proteins was assessed using immunohistochemistry. Expression of PKC theta was detected in 22 of 30 cases (73%), Bcl-10 in 20 of 30 (67%) and P-p65(Ser536) in 21 of 30 (70%). Bcl-10+ tumours were associated with PKC theta (18 of 22) (P < 0.0001) and Pp65Ser536 (19 of 21) expression (P < 0.0001). Patients with Bcl-10+ or P-p65(Ser536+) tumours fared better, with a 5-year overall survival of 48 and 45%, respectively, versus 0% for negative tumours (P = 0.029 and P = 0.04, respectively). CONCLUSIONS: Bcl-10 is expressed in PTCLs, correlates with PKC theta and Pp65(Ser536) expression and seems to be associated with better survival.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Biomarcadores Tumorais/metabolismo , Linfoma de Células T Periférico/metabolismo , Linfoma de Células T Periférico/patologia , Fator de Transcrição RelA/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína 10 de Linfoma CCL de Células B , Feminino , Humanos , Imuno-Histoquímica , Isoenzimas/metabolismo , Masculino , Pessoa de Meia-Idade , Fosforilação , Prognóstico , Proteína Quinase C/metabolismo , Proteína Quinase C-theta , Estudos Retrospectivos , Serina/química , Taxa de Sobrevida , Análise Serial de Tecidos , Fator de Transcrição RelA/química , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...