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‣ Dynamics of immunosuppression in hamsters with experimental visceral leishmaniasis

FAZZANI, C.; GUEDES, P.A.; SENNA, A.; SOUZA, E.B.; GOTO, H.; LINDOSO, J.A.L.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica
Português
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Immunosuppression has been reported to occur during active visceral leishmaniasis and some factors such as the cytokine profile may be involved in this process. In the mouse model of cutaneous leishmaniasis using Leishmania (Leishmania) major, the Th1 response is related to protection while the Th2 response is related to disease progression. However, in hamsters, which are considered to be an excellent model for the study of visceral leishmaniasis, this dichotomy is not observed. Using outbred 45- to 60-day-old (140 to 150 g) male hamsters infected intraperitoneally with 2 x 10(7) L. (L.) chagasi amastigotes, we evaluated the immune response of spleen cells and the production of cytokines. We used 3 to 7 hamsters per group evaluated. We detected a preserved response to concanavalin A measured by index of proliferation during all periods of infection studied, while a proliferative response to Leishmania antigen was detected only at 48 and 72 h post-infection. Messenger RNA from cytokines type 1 (IL-2, TNF-α, IFN-γ) and type 2 (IL-4, IL-10 and TGF-β) detected by reverse transcriptase polymerase chain reaction and produced by spleen cells showed no qualitative difference between control non-infected hamsters and infected hamsters during any period of infection evaluated. Cytokines were measured by the DNA band intensity on agarose gel using the Image Lab 1D L340 software with no differences observed. In conclusion...

‣ Apoptose de linfócitos na imunossupressão da leismaniose visceral em hamsteres infectados com Leishmania (Leishmania) chagasi; Apoptosis of lymphocytes in immunosuppression leishmaniasis in hamsters infected with visceral Leishmania (Leishmania) chagasi

Fazzani, Camila
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/12/2010 Português
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Hamsteres infectados com Leishmania (L.) chagasi são considerados um dos melhores modelos para estudo de fatores relacionados à imunossupressão que ocorre durante a leishmaniose visceral ativa, pois apresenta manifestações clínicas similares ao que ocorre no homem e não conseguem controlar a infecção. Neste estudo, hamsteres infectados intraperitonealmente com 2x107 parasitos foram utilizados para avaliação de possíveis fatores envolvidos na dinâmica da imunossupressão. Os parâmetros avaliados foram a produção de citocinas de padrão Th1 e Th2, produção de óxido nítrico por células esplênicas e detecção de apoptose em linfócitos esplênicos em tempos precoces (6, 20, 48 e 72 horas), intermediários (7 e 15 dias) e tardios (30 e 60 dias) de infecção. Inicialmente avaliamos a carga parasitária no baço e observamos aumento progressivo dependente do tempo de infecção, ratificando que hamster infectado é um bom modelo para desenvolvimento de doença. A resposta celular frente a mitógeno e antígeno de Leishmania foi o parâmetro utilizado para avaliação de imunossupressão. Observamos resposta preservada à concanavalina A em todos os tempos de infecção e resposta preservada ao antígeno de Leishmania nos tempos precoces...

‣ Immunity and immunosuppression in experimental visceral leishmaniasis

Goto,H.; Lindoso,J.A.L.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2004 Português
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Leishmaniasis is a disease caused by protozoa of the genus Leishmania, and visceral leishmaniasis is a form in which the inner organs are affected. Since knowledge about immunity in experimental visceral leishmaniasis is poor, we present here a review on immunity and immunosuppression in experimental visceral leishmaniasis in mouse and hamster models. We show the complexity of the mechanisms involved and differences when compared with the cutaneous form of leishmaniasis. Resistance in visceral leishmaniasis involves both CD4+ and CD8+ T cells, and interleukin (IL)-2, interferon (IFN)- gamma, and IL-12, the latter in a mechanism independent of IFN- gamma and linked to transforming growth factor (TGF)-ß production. Susceptibility involves IL-10 but not IL-4, and B cells. In immune animals, upon re-infection, the elements involved in resistance are different, i.e., CD8+ T cells and IL-2. Since one of the immunopathological consequences of active visceral leishmaniasis in humans is suppression of T-cell responses, many studies have been conducted using experimental models. Immunosuppression is mainly Leishmania antigen specific, and T cells, Th2 cells and adherent antigen-presenting cells have been shown to be involved. Interactions of the co-stimulatory molecule family B7-CTLA-4 leading to increased level of TGF-ß as well as apoptosis of CD4+ T cells and inhibition of macrophage apoptosis by Leishmania infection are other components participating in immunosuppression. A better understanding of this complex immune response and the mechanisms of immunosuppression in experimental visceral leishmaniasis will contribute to the study of human disease and to vaccine development.

‣ Dynamics of immunosuppression in hamsters with experimental visceral leishmaniasis

Fazzani,C.; Guedes,P.A.; Senna,A.; Souza,E.B.; Goto,H.; Lindoso,J.A.L.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2011 Português
Relevância na Pesquisa
36.75648%
Immunosuppression has been reported to occur during active visceral leishmaniasis and some factors such as the cytokine profile may be involved in this process. In the mouse model of cutaneous leishmaniasis using Leishmania (Leishmania) major, the Th1 response is related to protection while the Th2 response is related to disease progression. However, in hamsters, which are considered to be an excellent model for the study of visceral leishmaniasis, this dichotomy is not observed. Using outbred 45- to 60-day-old (140 to 150 g) male hamsters infected intraperitoneally with 2 x 10(7) L. (L.) chagasi amastigotes, we evaluated the immune response of spleen cells and the production of cytokines. We used 3 to 7 hamsters per group evaluated. We detected a preserved response to concanavalin A measured by index of proliferation during all periods of infection studied, while a proliferative response to Leishmania antigen was detected only at 48 and 72 h post-infection. Messenger RNA from cytokines type 1 (IL-2, TNF-α, IFN-γ) and type 2 (IL-4, IL-10 and TGF-β) detected by reverse transcriptase polymerase chain reaction and produced by spleen cells showed no qualitative difference between control non-infected hamsters and infected hamsters during any period of infection evaluated. Cytokines were measured by the DNA band intensity on agarose gel using the Image Lab 1D L340 software with no differences observed. In conclusion...

‣ Effects of immunosuppression with tacrolimus and mycophenolate mofetil on renal histology and function in single kidney rats submitted to ischemia and reperfusion

Dias,Paulo Henrique Goulart Fernandes; Oliveira,Gabriel Augusto; Dias,Fernando Goulart Fernandes; Gomes,Regina de Paula Xavier; Tambara Filho,Renato; Fraga,Rogério de
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 Português
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PURPOSE: To evaluate renal histological changes and renal function in single kidney rats submitted to renal ischemia-reperfusion and to immunosuppression with tacrolimus and mycophenolate-mofetil. METHODS: Experimental study with 80 Wistar rats distributed into control, Sham and six other groups treated with immunosuppressive drugs. Animals undergoing surgery, right nephrectomy and left renal clamping, killed on the 14th day and analyzed for renal histology, urea and creatinine. RESULTS: The group receiving tacrolimus at higher doses (T3) showed renal histological lesions indicative of early nephrotoxicity, and significant increase in urea and creatinine. The group M (mycophenolate-mofetil alone) and the group M2 (mycophenolate-mofetil combined with half the usual dose of tacrolimus) presented a slight rise in serum urea. The groups using mycophenolate-mofetil alone or combined with tacrolimus showed creatinine levels similar to that of the group T3. CONCLUSIONS: Histologically, the association of injury by ischemia-reperfusion with the use of tacrolimus or mycophenolate-mofetil alone demonstrated a higher rate of renal changes typical of early nephrotoxicity. In laboratory, the combination of injury by ischemia-reperfusion with tacrolimus at higher doses proved to be nephrotoxic.

‣ Down-regulated donor-specific T-cell reactivity during successful tapering of immunosuppression after kidney transplantation

VAN BESOUW, N M; VAN DER MAST, B J; DE KUIPER, P; GREGOOR, P J H SMAK; VAESSEN, LENARD M B; IJZERMANS, J N M; VAN GELDER, T; WEIMAR, W
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Publicado em /05/2002 Português
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Stable cadaveric renal transplant patients were routinely converted from cyclosporin A (CsA) to either azathioprine (AZA) or mycophenolate mofetil (MMF) 1 year after transplantation to reduce the side effects of long-term immunosuppressive therapy. Thereafter, the AZA and MMF dose was gradually tapered to 50% at 2 years after transplantation. We questioned whether a reduction of immunosuppressive treatment results in a rise of donor-specific T-cell reactivity. Before transplantation (no immunosuppression), 1 year (high dose immunosuppression) and 2 years (low dose immunosuppression) after transplantation, the T-cell reactivity of peripheral blood mononuclear cells (PBMC) against donor and third-party spleen cells was tested in mixed lymphocyte cultures (MLC) and against tetanus toxoid (TET) to test the general immune response. We also measured the frequency of donor and third-party reactive helper (HTLpf) and cytotoxic (CTLpf) T-lymphocyte precursors in a limiting dilution assay. Donor-specific responses, calculated by relative responses (RR = donor/third-party reactivity), were determined. Comparing responses after transplantation during high dose immunosuppression with responses before transplantation (no immmunosuppression), the donor-specific MLC-RR (P = 0·04)...

‣ WEANING OF IMMUNOSUPPRESSION IN LIVER TRANSPLANT RECIPIENTS12

Mazariegos, George V.; Reyes, Jorge; Marino, Ignazio R.; Demetris, Anthony J.; Flynn, Bridget; Irish, William; McMichael, John; Fung, John J.; Starzl, Thomas E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 27/01/1997 Português
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Immunosuppression has been sporadically discontinued by noncompliant liver allograft recipients for whom an additional 4 1/2 years of follow-up is provided. These anecdotal observations prompted a previously reported prospective drug withdrawal program in 59 liver recipients. This prospective series has been increased to 95 patients whose weaning was begun between June 1992 and March 1996, 8.4±4.4 (SD) years after liver replacement. A further 4 1/2 years follow-up was obtained of the 5 self-weaned patients. The prospectively weaned recipients (93 livers; 2 liver/ kidney) had undergone transplantation under immunosuppression based on azathioprine (AZA, through 1979), cyclosporine (CsA, 1980–1989), or tacrolimus (TAC, 1989–1994). In patients on CsA or TAC based cocktails, the adjunct drugs were weaned first in the early part of the trial. Since 1994, the T cell–directed drugs were weaned first. Three of the 5 original self-weaned recipients remain well after drug-free intervals of 14 to 17 years. A fourth patient died in a vehicular accident after 11 years off immunosuppression, and the fifth patient underwent retransplantation because of hepatitis C infection after 9 drug-free years; their allografts had no histopathologic evidence of rejection. Eighteen (19%) of the 95 patients in the prospective series have been drug free for from 10 months to 4.8 years. In the total group...

‣ Prostaglandin E2–prostoglandin E receptor subtype 4 (EP4) signaling mediates UV irradiation-induced systemic immunosuppression

Soontrapa, Kitipong; Honda, Tetsuya; Sakata, Daiji; Yao, Chengcan; Hirata, Takako; Hori, Shohei; Matsuoka, Toshiyuki; Kita, Yoshihiro; Shimizu, Takao; Kabashima, Kenji; Narumiya, Shuh
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
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UV radiation induces systemic immunosuppression. Because nonsteroidal anti-inflammatory drugs suppress UV-induced immunosuppression, prostanoids have been suspected as a crucial mediator of this UV effect. However, the identity of the prostanoid involved and its mechanism of action remain unclear. Here, we addressed this issue by subjecting mice deficient in each prostanoid receptor individually or mice treated with a subtype-specific antagonist to UV irradiation. Mice treated with an antagonist for prostaglandin E receptor subtype 4 (EP4), but not those deficient in other prostanoid receptors, show impaired UV-induced immunosuppression, whereas administration of an EP4 agonist rescues the impairment of the UV-induced immunosuppression in indomethacin-treated mice. The EP4 antagonist treatment suppresses an increase in the number of CD4+/forkhead box P3-positive (Foxp3+) regulatory T cells (Treg cells) in the peripheral lymph nodes (LNs) and dendritic cells expressing DEC205 in the LNs and the skin after UV irradiation. Furthermore, the EP4 antagonist treatment down-regulates UV-induced expression of receptor activator of NF-κB ligand (RANKL) in skin keratinocytes. Finally, administration of anti-RANKL antibody abolishes the restoration of UV-induced immunosuppression by EP4 agonism in indomethacin-treated mice. Thus...

‣ Pathway-Based Analysis of a Melanoma Genome-Wide Association Study: Analysis of Genes Related to Tumour-Immunosuppression

Schoof, Nils; Iles, Mark M.; Bishop, D. Timothy; Newton-Bishop, Julia A.; Barrett, Jennifer H.; consortium, GenoMEL
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 27/12/2011 Português
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Systemic immunosuppression is a risk factor for melanoma, and sunburn-induced immunosuppression is thought to be causal. Genes in immunosuppression pathways are therefore candidate melanoma-susceptibility genes. If variants within these genes individually have a small effect on disease risk, the association may be undetected in genome-wide association (GWA) studies due to low power to reach a high significance level. Pathway-based approaches have been suggested as a method of incorporating a priori knowledge into the analysis of GWA studies. In this study, the association of 1113 single nucleotide polymorphisms (SNPs) in 43 genes (39 genomic regions) related to immunosuppression have been analysed using a gene-set approach in 1539 melanoma cases and 3917 controls from the GenoMEL consortium GWA study. The association between melanoma susceptibility and the whole set of tumour-immunosuppression genes, and also predefined functional subgroups of genes, was considered. The analysis was based on a measure formed by summing the evidence from the most significant SNP in each gene, and significance was evaluated empirically by case-control label permutation. An association was found between melanoma and the complete set of genes (pemp = 0.002)...

‣ Up-regulation of Interleukin-8, Interleukin-10, Monocyte Chemotactic Protein-1, and Monocyte Chemotactic Protein-3 in Peripheral Blood Monocytes in Stable Lung Transplant Recipients: Are Immunosuppression Regimens Working?

Hodge, G.; Hodge, S.; Reynolds, P.; Holmes, M.
Fonte: Lippincott Williams & Wilkins Publicador: Lippincott Williams & Wilkins
Tipo: Artigo de Revista Científica
Publicado em //2005 Português
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BACKGROUND: Alveolar macrophages are a major source of inflammatory cytokines and chemokines involved in the pathogenesis of lung transplant rejection and are derived from blood monocytes that migrate to the lung. Levels of monocyte cytokines and chemokines that may be relevant in transplant rejection have not previously been determined in transplant recipients. We hypothesized that production of these inflammatory mediators by blood monocytes may be up-regulated despite the use of potent immunosuppression therapy. METHOD: To investigate this, whole blood from 9 stable lung transplant recipients and 12 control volunteers was stimulated with lipopolysaccharide in vitro, and intracellular chemokine and cytokine production were determined with multiparameter flow cytometry. RESULTS: Monocyte production of chemokines interleukin (IL)-8, monocyte chemotactic protein (MCP)-1, and MCP-3, and anti-inflammatory cytokine IL-10 were significantly increased in the lung transplant group, but IL-6, tumor necrosis factor-alpha, IL-1alpha, IL-12, macrophage inflammatory protein-1alpha, macrophage inflammatory protein-1beta, and transforming growth factor-beta levels were unchanged. CONCLUSIONS: Because MCP-3 is a major chemoattractant for leukocytes to sites of antigenic challenge and is a natural ligand for MCP-1 receptor...

‣ Mast cells, neuropeptides, histamine, and prostaglandins in UV-induced systemic immunosuppression

Hart, P.; Townley, S.; Grimbaldeston, M.; Kahlil, Z.; Finlay-Jones, J.
Fonte: Academic Press Inc Elsevier Science Publicador: Academic Press Inc Elsevier Science
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
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There is a direct correlation between dermal mast cell prevalence in dorsal skin of different mouse strains and susceptibility to UVB-induced systemic immunosuppression; highly UV-susceptible C57BL/6 mice have a high dermal mast cell prevalence while BALB/c mice, which require considerable UV radiation for 50% immunosuppression, have a low mast cell prevalence. There is also a functional link between the prevalence of dermal mast cells and susceptibility to UVB- and cis-urocanic acid (UCA)-induced systemic immunosuppression. Mast cell-depleted mice are unresponsive to UVB or cis-UCA for systemic immunosuppression unless they are previously reconstituted at the irradiated or cis-UCA-administered site with bone marrow-derived mast cell precursors. cis-UCA does not stimulate mast cell degranulation directly. Instead, in support of studies showing that neither UVB nor cis-UCA was immunosuppressive in capsaicin-treated, neuropeptide-depleted mice, cis-UCA-stimulated neuropeptide release from sensory c-fibers which, in turn, could efficiently degranulate mast cells. Studies in mice suggested that histamine, and not tumor necrosis factor alpha (TNF-alpha), was the product from mast cells that stimulated downstream immunosuppression. Histamine receptor antagonists reduced by approximately 60% UVB and cis-UCA-induced systemic immunosuppression. Indomethacin administration to mice had a similar effect which was not cumulative with the histamine receptor antagonists. Histamine can stimulate keratinocyte prostanoid production. We propose that both histamine and prostaglandin E(2) are important in downstream immunosuppression; both are regulatory molecules supporting the development of T helper 2 cells and reduced expression of type 1 immune responses such as a contact hypersensitivity reaction.; http://www.elsevier.com/wps/find/journaldescription.cws_home/622914/description#description; Prue H. Hart...

‣ Immunosuppression and other risk factors for early and late non-Hodgkin lymphoma after kidney transplantation

van Leeuwen, M.; Grulich, A.; Webster, A.; McCredie, M.; Stewart, J.; McDonald, S.; Amin, J.; Kaldor, J.; Chapman, J.; Vajdic, C.
Fonte: American Society of Hematology Publicador: American Society of Hematology
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
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Non-Hodgkin lymphoma (NHL) incidence is greatly increased after kidney transplantation. NHL risk was investigated in a nationwide cohort of 8164 kidney transplant recipients registered on the Australia and New Zealand Dialysis and Transplant Registry. NHL diagnoses were ascertained using linkage with national cancer registry records. Multivariate Poisson regression was used to compute incidence rate ratios (IRRs) with 95% confidence intervals (CIs) comparing risk by transplant function, and risk factors for early (< 2 years) and late (≥ 2 years) NHL during the first transplantation. NHL occurred in 133 patients. Incidence was strikingly lower after transplant failure and cessation of immunosuppression than during transplant function (IRR, 0.25; 95% CI, 0.08-0.80; P = .019). Early NHL (n = 27) was associated with Epstein-Barr virus (EBV) seronegativity at transplantation (IRR, 4.66; 95% CI, 2.10-10.36, P < .001) and receipt of T cell–depleting antibodies (IRR, 2.39; 95% CI, 1.08-5.30; P = .031). Late NHL (n = 79) was associated with increasing year of age (IRR, 1.02; 95% CI, 1.01-1.04; P = .006), increasing time since transplantation (P < .001), and current use of calcineurin inhibitors (IRR, 3.13; 95% CI, 1.53-6.39; P = .002). These findings support 2 mechanisms of lymphomagenesis...

‣ Immunosuppression and Other Risk Factors for Lip Cancer after Kidney Transplantation

van Leeuwen, M.; Grulich, A.; McDonald, S.; McCredie, M.; Amin, J.; Stewart, J.; Webster, A.; Chapman, J.; Vajdic, C.
Fonte: Amer Assoc Cancer Research Publicador: Amer Assoc Cancer Research
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
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Incidence of lip cancer is markedly increased after kidney transplantation. Immunosuppression and other risk factors for lip cancer were investigated in a population-based, nationwide cohort of 8,162 kidney transplant recipients registered on the Australia and New Zealand Dialysis and Transplant Registry (1982-2003). Lip cancer diagnoses were ascertained using probabilistic data linkage with the Australian National Cancer Statistics Clearing House. Standardized incidence ratios were used to compare lip cancer risk by subsite of lip and during periods of transplant function and failure. Risk factors during the first functioning transplant were examined using multivariate Poisson regression. Lip cancer was diagnosed in 203 patients. All cases were of squamous cell origin and mostly (77%) affected the lower vermillion. Cases occurred predominantly during periods of transplant function, with incidence decreasing to pretransplantation level on transplant failure and cessation of immunosuppression. During transplant function, cancer of the lower vermillion was associated with increasing year of age [incidence rate ratio (IRR), 1.03; 95% confidence interval (95% CI), 1.02-1.05], greater time since transplantation (P < 0.001), smoking (IRR...

‣ Effect of reduced immunosuppression after kidney transplant failure on risk of cancer: population based retrospective cohort study

van Leeuwen, M.; Webster, A.; McCredie, M.; Stewart, J.; McDonald, S.; Amin, J.; Kaldor, J.; Chapman, J.; Vajdic, C.; Grulich, A.
Fonte: British Med Journal Publ Group Publicador: British Med Journal Publ Group
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
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Objective: To compare cancer incidence in kidney transplant recipients during periods of transplant function (and immunosuppression) and after transplant failure (when immunosuppression is ceased or reduced). Design, setting, and participants: Nationwide, population based retrospective cohort study of 8173 Australian kidney transplant recipients registered on the Australia and New Zealand Dialysis and Transplant Registry who first received a transplant during 1982-2003. Incident cancers were ascertained using linkage with national cancer registry records. Main outcome measures: Cancer-specific standardised incidence ratios for periods of transplant function and for dialysis after transplant failure. Incidence was compared between periods using multivariate incidence rate ratios adjusted for current age, sex, and duration of transplantation. Results: All cases of Kaposi’s sarcoma occurred during transplant function. Standardised incidence ratios were significantly elevated during transplant function, but not during dialysis after transplant failure, for non-Hodgkin’s lymphoma, lip cancer, and melanoma. For each of these cancers, incidence was significantly lower during dialysis after transplant failure in multivariate analysis (incidence rate ratios 0.20 (95% CI 0.06 to 0.65) for non-Hodgkin’s lymphoma...

‣ Acute erythemal ultraviolet radiation causes systemic immunosuppression in the absence of increased 25-hydroxyvitamin D-₃ levels in male mice; Acute erythemal ultraviolet radiation causes systemic immunosuppression in the absence of increased 25-hydroxyvitamin D-(3) levels in male mice

Gorman, S.; Scott, N.; Tan, D.; Weeden, C.; Tuckey, R.; Bisley, J.; Grimbaldeston, M.; Hart, P.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2012 Português
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Vitamin D is synthesised by ultraviolet (UV) irradiation of skin and is hypothesized to be a direct mediator of the immunosuppression that occurs following UV radiation (UVR) exposure. Both UVR and vitamin D drive immune responses towards tolerance by ultimately increasing the suppressive activities of regulatory T cells. To examine a role for UVR-induced vitamin D, vitamin D₃-deficient mice were established by dietary vitamin D₃ restriction. In comparison to vitamin D₃-replete mice, vitamin D₃-deficient mice had significantly reduced serum levels of 25-hydroxyvitamin D₃ (25(OH)D₃, <20 nmol.L⁻¹) and 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃, <20 pmol.L⁻¹). Following either acute erythemal UVR, or chronic sub-erythemal UVR (8 exposures over 4 weeks) treatment, serum 25(OH)D₃ levels significantly increased in vitamin D₃-deficient female but not male mice. To determine if UVR-induced vitamin D was a mediator of UVR-induced systemic immunosuppression, responses were measured in mice that were able (female) or unable (male) to increase systemic levels of 25(OH)D₃ after UVR. Erythemal UVR (≥4 kJ/m²) suppressed contact hypersensitivity responses (T helper type-1 or -17), aspects of allergic airway disease (T helper type-2) and also the in vivo priming capacity of bone marrow-derived dendritic cells to a similar degree in female and male vitamin D₃-deficient mice. Thus...

‣ Peripheral natural killer cell and allo-stimulated T-cell function in kidney transplant recipients associate with cancer risk and immunosuppression-related complications

Hope, C.M.; Troelnikov, A.; Hanf, W.; Jesudason, S.; Coates, P.T.; Heeger, P.S.; Carroll, R.P.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
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Reducing immunosuppression has been proposed as a means of preventing cancer in kidney transplant recipients but this can precipitate graft rejection. Here we tested whether anti-tumor natural killer (NK) cell and allo-responsive T-cell function in kidney transplant recipients may predict cancer risk and define risk of rejection. NK cell function was measured by the release of lactate dehydrogenase and T-cell allo-response by interferon-γ quantification using a panel of reactive T-cell enzyme-linked immunospot (ELISPOT) in 56 kidney transplant recipients with current or past cancer and 26 kidney transplant recipients without cancer. NK function was significantly impaired and the allo-response was significantly lower in kidney transplant recipients with cancer. With prospective follow-up, kidney transplant recipients with poor NK cell function had a hazard ratio of 2.1 (95% confidence interval 0.97-5.00) for the combined end point of metastatic cancer, cancer-related death, or septic death. Kidney transplant recipients with low interferon-γ release were also more likely to reach this combined end point. Thus, posttransplant monitoring of allo-immunity and NK cell function is useful for assessing the risk of over immunosuppression for the development of malignancy and/or death from cancer or sepsis.; Christopher M Hope...

‣ Intracellular cytokines in blood T cells in lung transplant patients - a more relevant indicator of immunosuppression than drug levels

Hodge, G.; Hodge, S.; Reynolds, P.; Holmes, M.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2005 Português
Relevância na Pesquisa
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Allograft rejection remains a major cause of morbidity and mortality following lung transplantation and is associated with an increase in T-cell pro-inflammatory cytokine expression. Systemic levels of immunosuppressive drugs used to reduce pro-inflammatory cytokine expression are closely monitored to their 'therapeutic range'. However, it is currently unknown if levels of these drugs correlate with pro-inflammatory cytokine expression in peripheral blood T cells. To investigate the immunomodulatory effects of currently used immunosuppressive regimes on peripheral blood T-cell cytokine production, whole blood from stable lung transplant patients and control volunteers were stimulated in vitro and cytokine production by CD8+ and CD4+ T-cell subsets determined using multiparameter flow cytometry. T-cell IL-2 and TNFalpha production was significantly reduced from lung transplant patients compared to controls. CD4+ T-cell production of IFNgamma was also significantly reduced from lung transplant patients but production of IFNgamma by CD8+ T cells remained unchanged. There was an excellent correlation between the percentage of CD8+ T cells and the percentage of CD8+ T cells producing IFNgamma from transplant patients. T-cell IL-4 and CD8+ T-cell production of TGFbeta was significantly increased from lung transplant patients. We now provide evidence that current immunosuppression protocols have limited effect on peripheral blood IFNgamma production by CD8+ T-cells but do up-regulate T-cell anti-inflammatory cytokines. Drugs that effectively reduce IFNgamma production by CD8+ T cells may improve current protocols for reducing graft rejection in these patients. Intracellular cytokine analysis using flow cytometry may be a more appropriate indicator of immunosuppression than drug levels in these patients. This technique may prove useful in optimizing therapy for individual patients.

‣ A child with autoimmune polyendocrinopathy candidiasis and ectodermal dysplasia treated with immunosuppression: a case report

O'Gorman, Clodagh S; Shulman, Rayzel M; Lara-Corrales, Irene; Pope, Elena; Marcon, Margaret; Grasemann, Hartmut; Schneider, Rayfel; Upton, Julia; Sochett, Etienne B; Kolfin, Dror; Cohen, Eyal
Fonte: BioMed Central Ltd Publicador: BioMed Central Ltd
Tipo: info:eu-repo/semantics/article; all_ul_research; ul_published_reviewed
Português
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peer-reviewed; Introduction: Common features of autoimmune polyendocrinopathy-candidiasis-ectodermal dysplasia include candidiasis, hypoparathyroidism and hypoadrenalism. The initial manifestation of autoimmune polyendocrinopathy-candidiasis-ectodermal dysplasia may be autoimmune hepatitis, keratoconjunctivitis, frequent fever with or without a rash, chronic diarrhea, or different combinations of these with or without oral candidiasis. Case presentation: We discuss a profoundly affected 2.9-year-old Caucasian girl of Western European descent with a dramatic response to immunosuppression (initially azathioprine and oral steroids, and then subsequently mycophenolate mofetil monotherapy). At four years of follow-up, her response to mycophenolate mofetil is excellent. Conclusion: The clinical features of autoimmune polyendocrinopathy-candidiasis-ectodermal dysplasia may continue for years before some of the more common components appear. In such cases, it may be life-saving to diagnose autoimmune polyendocrinopathy-candidiasis-ectodermal dysplasia and commence therapy with immunosuppressive agents. The response of our patient to immunosuppression with mycophenolate mofetil has been dramatic. It is possible that other patients with this condition might also benefit from immunosuppression.

‣ Transplant Coordinators' Perceived Impact of Availability of Multiple Generic Immunosuppression Therapies on Patients, Workload, and Posttransplant Maintenance Therapy

Parker, K.; Zagadailov, E. A.; Bruno, A. S.; Wiland, A. M.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
27.03877%
Background. No studies have evaluated the impact of multiple generic immunosuppression medications on transplant coordinators (TCs) and patients. Methods. A cross-sectional, multicenter online survey of TCs managing transplant recipients' outpatient immunosuppression was undertaken to assess TCs' perceptions of the impact of multiple generic immunosuppression therapies on patients and workload. Results. Forty-six of 106 transplant centers contacted (43%) completed the survey, with usable information from 34 TCs (53% in centers performing >100 solid organ transplants annually, 82% registered nurses, and 68% with >5-year experience working with transplant patients). TCs indicated that “change in strength,” “switching from branded to generics,” “heavy pill burden,” and “switching from one generic to another” were the four most frequent reasons for patient confusion regarding immunosuppression. TCs reported increased patient confusion over the previous year for patients on generic immunosuppression therapy: 44% answered ≥3 patient calls/day regarding confusion over immunosuppression therapy. Most TCs indicated increased workload since the introduction of generic immunosuppression therapy. TCs perceived “acute rejection rates...

‣ Estrategias para revertir la inmunosupresión en el fenómeno de tolerancia a endotoxinas; Strategies to reverse the immunosuppression in the phenomenon of endotoxin tolerance

Rearte, María Bárbara
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2011 Português
Relevância na Pesquisa
36.84147%
Los fenómenos de sepsis y shock séptico pueden ser causados por bacterias Gram- positivas y negativas como también por otros microorganismos. En el caso de las bacterias Gram-negativas, las endotoxinas, componentes normales de la pared bacteriana, también conocidas como lipopolisacáridos (LPS), han sido consideradas como uno de los principales agentes causales de los efectos indeseables de estas enfermedades. La respuesta a LPS implica, en principio, la generación de un estado inflamatorio, caracterizado por la rápida secreción de citoquinas proinflamatorias como el factor de necrosis tumoral (TNF)-α, interleuquina (IL) -1, IL-6, e interferón (IFN)-γ, seguido por un estado anti-inflamatorio en donde predominan mediadores como la IL-10, el factor de transformación del crecimiento-β (TGF)-β o glucocorticoides (GC), los cuales conducen al huésped a un estado de refractariedad temporal frente a una nueva exposición al LPS, un proceso conocido como tolerancia a LPS o tolerancia a endotoxina. Si bien se ha considerado como un mecanismo de protección frente al desarrollo de una sepsis o una inflamación sistémica, la tolerancia a endotoxina ha sido también señalada como una de las causas principales de la inmunosupresión inespecífica tanto humoral como celular descrita en dichos pacientes. En este trabajo demostramos...