66 resultados para IMMUNOSUPPRESSION

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Non-melanoma skin cancers (NMSCs) are the most common malignancies after solid organ transplantation. Their incidence increases with time after transplantation. Calcineurin-inhibitors (CNIs) and azathioprine are known as skin neoplasia-initiating and -enhancing immunosuppressants. In contrast, increasing clinical experience suggests a relevant antiproliferative effect of mammalian target of rapamycin inhibitors, also named proliferation signal inhibitors (PSIs). We report the case of a cardiac allograft recipient with an impressive and consolidated reduction of recurrent NMSC, observed after conversion from CNI-therapy to a PSI-based protocol.

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The toxicity of long-term immunosuppressive therapy has become a major concern in long-term follow-up of heart transplant recipients. In this respect the quality of renal function is undoubtedly linked to cyclosporin A (CsA) drug levels. In cardiac transplantation, specific CsA trough levels have historically been maintained between 250 and 350 micrograms/L in many centers without direct evidence for the necessity of such high levels while using triple-drug immunosuppression. This retrospective analysis compares the incidence of acute and chronic graft rejection as well as overall mortality between groups of patients with high (250 to 350 micrograms/L) and low (150 to 250 micrograms/L) specific CsA trough levels. A total of 332 patients who underwent heart transplantation between October 1985 and October 1992 with a minimum follow-up of 30 days were included in this study (46 women and 276 men; aged, 44 +/- 12 years; mean follow-up, 1,122 +/- 777 days). Standard triple-drug immunosuppression included first-year specific CsA target trough levels of 250 to 300 micrograms/L. Patients were grouped according to their average creatinine level in the first postoperative year (group I, < 130 mumol/L, n = 234; group II, > or = 130 mumol/L, n = 98). The overall 5-year survival excluding the early 30-day mortality was 92% (group I, 216/232) and 91% (group II, 89/98) with 75% of the mortality due to chronic rejection. The rate of rejection for the entire follow-up period was similar in both groups (first year: group I, 3.2 +/- 2.6 rejection/patient/year; group II, 3.6 +/- 2.7 rejection/patient/year; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

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A cyclosporine (CsA)-based immunosuppression is associated with an increased incidence of cholelithiasis after heart transplantation. It is not known if tacrolimus (Tac) has comparable biliary side effects in humans. We evaluated the incidence of gallbladder sludge and cholelithiasis under Tac-based immunosuppression by ultrasound examinations in 31 cardiac transplants (25 male, 6 female, mean age: 59 ' 11 years). Data were compared to 57 patients (47 male, 10 female, mean age: 58 ' 11 years) who received CsA-based immunosuppression. 6 patients receiving Tac and 6 patients receiving CsA had already gallstones prior to transplantation so that finally 25 patients of the Tac group and 51 patients of the CsA group could be evaluated. In the Tac group the incidence of biliary sludge was 4% (1 of 25), of gallstones 28% (7 of 25). In comparison, patients receiving CsA developed biliary sludge in also 4% (2 of 51) and gallstones in 25% (13 of 51). Nine of 42 males in the CsA group (21%) and eight of 20 males in the Tac group (40%) developed either gallstones or sludge (n.s). Six of nine females in the CsA group (67%), but none of five females in the Tac group (0%) developed either gallstones or sludge (p = 0.01). In summary, the incidence of biliary disease in patients with Tac is comparable with CsA-based immunosuppression. We recommend regular sonographical examinations to detect biliary diseases as early as possible. In cases of clinically, laboratory and sonographical signs of cholecystitis cholecystectomy is indicated. It seems that towards lithogenicity female patients benefit more from a Tac-based treatment because the occurrence of gallstones is rare.

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The efficacy of everolimus with reduced cyclosporine in de novo heart transplant patients has been demonstrated convincingly in randomized studies. Moreover, everolimus-based immunosuppression in de novo heart transplant recipients has been shown in two randomized trials to reduce the increase in maximal intimal thickness based on intravascular ultrasound, indicating attenuation of cardiac allograft vasculopathy (CAV). Randomized trials of everolimus in de novo heart transplantation have also consistently shown reduced cytomegalovirus infection versus antimetabolite therapy. In maintenance heart transplantation, conversion from calcineurin inhibitors to everolimus has demonstrated a sustained improvement in renal function. In de novo patients, a renal benefit may only be achieved if there is an adequate reduction in exposure to calcineurin inhibitor therapy. Delayed introduction of everolimus may be appropriate in patients at high risk of wound healing complications, e.g. diabetic patients or patients with ventricular assist device. The current evidence base suggests that the most convincing reasons for use of everolimus from the time of heart transplantation are to slow the progression of CAV and to lower the risk of cytomegalovirus infection. A regimen of everolimus with reduced-exposure calcineurin inhibitor and steroids in de novo heart transplant patients represents a welcome addition to the therapeutic armamentarium.

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Patients with autoimmune inner ear disease develop rapidly progressive sensorineural hearing loss over a period of several weeks or months, often accompanied by vestibular loss. This disease can occur as a distinct clinical entity or in association with an underlying autoimmune disorder. Treatment comprises immunosuppression by corticosteroids, cytostatic drugs or tumor necrosis factor- antagonists. We report histopathological and immunohistochemical findings of the inner ear of a patient with a granulomatous inner ear disease suffering from Crohn's disease that was nonresponsive to treatment and who underwent surgery for bilateral cochlear implants.

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Functional disruption of dendritic cells (DC) is an important strategy for viral pathogens to evade host defences. In this context, porcine circovirus type 2 (PCV2), a single-stranded DNA virus, impairs plasmacytoid DC (pDC) and conventional DC activation by certain viruses or Toll-like receptor (TLR) ligands. This inhibitory capacity is associated with the viral DNA, but the impairment does not affect all signalling cascades; TLR7 ligation by small chemical molecules will still induce interleukin-6 (IL-6) and tumour necrosis factor-α secretion, but not interferon-α or IL-12. In this study, the molecular mechanisms by which silencing occurs were investigated. PP2, a potent inhibitor of the Lyn and Hck kinases, produced a similar profile to the PCV2 DNA interference with cytokine secretion by pDC, efficiently inhibiting cell activation induced through TLR9, but not TLR7, ligation. Confocal microscopy and cytometry analysis strongly suggested that PCV2 DNA impairs actin polymerization and endocytosis in pDC and monocyte-derived DC, respectively. Altogether, this study delineates for the first time particular molecular mechanisms involved in PCV2 interference with DC danger recognition, which may be responsible for the virus-induced immunosuppression observed in infected pigs.

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Swiss clinical practice guidelines for skin cancer in organ transplant recipients Transplant patients have increased over the last decades. As a consequence of long-term immunosuppression, skin cancer, in particular squamous cell carcinoma (SCC), has become an important problem. Screening and education of potential organ transplant recipients (OTRs) regarding prevention of sun damage and early recognition of skin cancer are important before transplantation. Once transplanted, OTRs should be seen yearly by a dermatologist to ensure compliance with sun avoidance as well as for treatment of precancerosis and SCC. Early removal is the best treatment for SCC. Reduction of immunosuppression, switch to mTOR inhibitors and chemoprevention with acitretin may reduce the incidence of SCC. The dermatological follow-up of OTRs should be integrated into a comprehensive post-transplant management strategy.

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Immunoglobulin (Ig)G antineutrophil cytoplasmic autoantibodies are causally associated with necrotizing vasculitides that are characterized immunopathologically by little or no deposition of immunoreactants, such as Wegener granulomatosis, microscopic polyangiitis, Churg-Strauss angiitis, "renal-limited" vasculitis and a number of drug-induced vasculitides. Clinical routine testing targets the antigens myeloperoxidase and proteinase 3. However, in all of the conditions mentioned, the renal histopathologic findings are indistinguishable. Churg-Strauss angiitis (characterized by necrotizing vasculitis, granulomatous inflammation and tissue eosinophilia), Wegener granulomatosis (characterized by necrotizing vasculitis and granulomatous inflammation) and microscopic polyangiitis (characterized by necrotizing vasculitis) often present with fever, weight loss and a multisystem involvement (ear, nose, throat, lung, eyes, peripheral nerve and heart). Fifty years ago these conditions were very often fatal within 6 months of diagnosis. The introduction of corticosteroids and cyclophosphamide has resulted in a dramatic clinical benefit. Patients who develop treatment-related morbidity can be switched from cyclophosphamide to azathioprine after achieving remission. In patients with less severe disease, methotrexate achieves remission with a success rate similar to that of cyclophosphamide. Plasma exchange, in association with immunosuppression, is likely to be a beneficial therapy for patients with severe kidney disease or pulmonary hemorrhage.

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The central issue in organ transplantation remains suppression of allograft rejection. Immunosuppression can be achieved by depleting lymphocytes, diverting lymphocyte traffic, or blocking lymphocyte response pathways. Immunosuppressive drugs include small-molecule drugs, depleting and nondepleting protein drugs (polyclonal and monoclonal antibodies), fusion proteins, intravenous immune globulin, and glucocorticoids. Small-molecule immunosuppressive agents include calcineurin-inhibitors (cyclosporine, tacrolimus), Target-of-Rapamycin Inhibitors (Sirolimus, Everolimus), inhibitors of nucleotide synthesis and azathioprine. The review covers the mode of action of these drugs with a special focus on belatacept, a new promising fusion protein. Different immuo-suppressive strategies mean also different safety profiles. Common side effects include the consequences of diminished immuno- response, i.e. infections and cancer (mainly involving the skin). Toxic side effects of immunosuppressive drugs range in a wide spectrum that involves almost every organ. The major interest of this toxic effects is the cardiovascular tolerance (with large differences from drug to drug), that are discussed seperately. The calcineurin- and mTOR-inhibitors are both metabolized by the CYP450 3A4 enzyme, which is also involved in the metabolism of many other drugs. The review discusses the most important interactions that in- or decreases the through level of these drugs.

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Background Purified thymus extracts (pTE) and synthetic thymic peptides (sTP) are thought to enhance the immune system of cancer patients in order to fight the growth of tumour cells and to resist infections due to immunosuppression induced by the disease and antineoplastic therapy. Objectives To evaluate the effectiveness of pTE and sTP for the management of cancer. Search methods We searched CENTRAL (The Cochrane Library 2010, Issue 3), MEDLINE, EMBASE, AMED, BIOETHICSLINE, BIOSIS, CATLINE, CISCOM, HEALTHSTAR, HTA, SOMED and LILACS (to February 2010). Selection criteria Randomised trials of pTE or sTP in addition to chemotherapy or radiotherapy, or both, compared to the same regimen with placebo or no additional treatment in adult cancer patients. Data collection and analysis Two authors independently extracted data from published trials. We derived odds ratios (OR) from overall survival (OS) and disease-free survival (DFS) rates, tumour response (TR) rates, and rates of adverse effects (AE) related to antineoplastic treatments. We used a random-effects model for meta-analysis. Main results We identified 26 trials (2736 patients). Twenty trials investigated pTE (thymostimulin or thymosin fraction 5) and six trials investigated sTP (thymopentin or thymosin α1). Twenty-one trials reported results for OS, six for DFS, 14 for TR, nine for AE and 10 for safety of pTE and sTP. Addition of pTE conferred no benefit on OS (RR 1.00, 95% CI 0.79 to 1.25); DFS (RR 0.97, 95% CI 0.82 to 1.16); or TR (RR 1.07, 95% CI 0.92 to 1.25). Heterogeneity was moderate to high for all these outcomes. For thymosin α1 the pooled RR for OS was 1.21 (95% CI 0.94 to 1.56, P = 0.14), with low heterogeneity; and 3.37 (95% CI 0.66 to 17.30, P = 0.15) for DFS, with moderate heterogeneity. The pTE reduced the risk of severe infectious complications (RR 0.54, 95% CI 0.38 to 0.78, P = 0.0008; I² = 0%). The RR for severe neutropenia in patients treated with thymostimulin was 0.55 (95% CI 0.25 to 1.23, P = 0.15). Tolerability of pTE and sTP was good. Most of the trials had at least a moderate risk of bias. Authors' conclusions Overall, we found neither evidence that the addition of pTE to antineoplastic treatment reduced the risk of death or disease progression nor that it improved the rate of tumour responses to antineoplastic treatment. For thymosin α1, there was a trend for a reduced risk of dying and of improved DFS. There was preliminary evidence that pTE lowered the risk of severe infectious complications in patients undergoing chemotherapy or radiotherapy.

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Recurrence of chronic hepatitis C and progressive fibrosis in liver transplants is frequent and impairs both graft and patient survival. Whether or not the choice of immunosuppression affects progression of fibrosis remains unclear. The aim of the present study was to compare the potential of the commonly used immunosuppressants to halt experimental liver fibrosis progression.

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Hand transplantation has been indicated in selective patients after traumatic upper extremity amputation and only performed in a few centers around the world for the last decade. In comparison to solid organ transplantation, there is a challenge to overcome the host immunological barrier due to complex antigenicity of the different included tissues, the skin being the most susceptible to rejection. Patients require lifelong immunosuppression for non life-threatening conditions. Minimization of maintenance immunosuppression represents the key step for promoting wider applicability of hand transplantation. Current research is working towards the understanding mechanisms of composite tissue allograft (CTA) rejection. Worldwide, in 51 patients 72 hands (21 double hand transplants) and once both arms have been successfully transplanted since 1998.

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High levels of HIV-1 replication during the chronic phase of infection usually correlate with rapid progression to severe immunodeficiency. However, a minority of highly viremic individuals remains asymptomatic and maintains high CD4⁺ T cell counts. This tolerant profile is poorly understood and reminiscent of the widely studied nonprogressive disease model of SIV infection in natural hosts. Here, we identify transcriptome differences between rapid progressors (RPs) and viremic nonprogressors (VNPs) and highlight several genes relevant for the understanding of HIV-1-induced immunosuppression. RPs were characterized by a specific transcriptome profile of CD4⁺ and CD8⁺ T cells similar to that observed in pathogenic SIV-infected rhesus macaques. In contrast, VNPs exhibited lower expression of interferon-stimulated genes and shared a common gene regulation profile with nonpathogenic SIV-infected sooty mangabeys. A short list of genes associated with VNP, including CASP1, CD38, LAG3, TNFSF13B, SOCS1, and EEF1D, showed significant correlation with time to disease progression when evaluated in an independent set of CD4⁺ T cell expression data. This work characterizes 2 minimally studied clinical patterns of progression to AIDS, whose analysis may inform our understanding of HIV pathogenesis.

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Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs, with glomerulonephritis representing a frequent and serious manifestation. SLE is characterized by the presence of various autoantibodies, including anti-DNA antibodies that occur in approximately 70% of patients with SLE and which contribute to disease pathogenesis. Consequently, immunosuppressive therapies are applied in the treatment of SLE to reduce autoantibody levels. However, increasing evidence suggests that DNA--especially double--stranded DNA-constitutes an important pathogenic factor that is able to activate inflammatory responses by itself in autoimmune diseases. Therefore, modifying the structure of DNA to reduce its pathogenicity might be a more targeted approach for the treatment of SLE than immunosuppression. This article presents information in support of this strategy, and discusses the potential methods of DNA structure manipulation--in light of data obtained from mouse models of SLE--including topoisomerase I inhibition, administration of DNase I, or modification of histones using heparin or histone deacetylase inhibitors.