Publications by authors named "Alvaro Pacheco-Silva"

This study evaluated the current practices of selecting cold storage preservation solutions in Brazil and their impact on delayed graft function (DGF) incidence and 1-year outcomes in kidney transplant recipients. A retrospective cohort study was conducted, including 3,134 brain-dead deceased donor kidney transplants performed between 2014 and 2015 in 18 Brazilian centers. The most commonly used preservation solution was Euro-collins (EC, 55.

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Among renal replacement therapies, preemptive kidney transplantation (PKT) presents the best clinical, social, and economic results. However, it is still infrequently chosen as first therapy for patients with irreversible kidney failure. Initiatives in different parts of the world were developed to identify the reasons why PKT is still not widely used and to facilitate the access of patients with end-stage kidney disease to the advantages associated with it.

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Background: The chronic use of immunosuppressive drugs is a key risk factor of death because of coronavirus disease 2019 (COVID-19) in kidney transplant recipients (KTRs), although no evident association between the class of immunosuppressive and outcomes has been observed. Thus, we aimed to compare COVID-19-associated outcomes among KTRs receiving 3 different immunosuppressive maintenance regimes.

Methods: This study included data from 1833 KTRs with COVID-19 diagnosed between March 20 and April 21 extracted from the national registry before immunization.

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This analysis, using data from the Brazilian kidney transplant (KT) COVID-19 study, seeks to develop a prediction score to assist in COVID-19 risk stratification in KT recipients. In this study, 1379 patients (35 sites) were enrolled, and a machine learning approach was used to fit models in a derivation cohort. A reduced Elastic Net model was selected, and the accuracy to predict the 28-day fatality after the COVID-19 diagnosis, assessed by the area under the ROC curve (AUC-ROC), was confirmed in a validation cohort.

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Background: Kidney transplant (KT) recipients are considered a high-risk group for unfavorable outcomes in the course of coronavirus disease 2019 (COVID-19).

Aim: To describe the clinical aspects and outcomes of COVID-19 among KT recipients.

Methods: This multicenter cohort study enrolled 1,680 KT recipients diagnosed with COVID-19 between March and November 2020, from 35 Brazilian centers.

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This retrospective multicenter (n = 18) cohort study evaluated the incidence, risk factors, and the impact of delayed graft function (DGF) on 1-year kidney transplant (KT) outcomes. Of 3992 deceased donor KT performed in 2014-2015, the incidence of DGF was 54%, ranging from 29.9% to 87.

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Background: Returning to dialysis after kidney graft loss (GL) is associated with a high risk of mortality, mainly in the first 3-6 months. The follow-up of patients with GL should be extended to better understand crude patient outcomes, mainly in emerging countries, where the transplantation activity has increased.

Methods: This is a historical single-center cohort study conducted in an emerging country (Brazil) that included 115 transplant patients with kidney allograft failure who were followed for 44.

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Increasing evidence shows the essential participation of gut microbiota in human health and diseases by shaping local and systemic immunity. Despite an accumulating body of studies showing that chronic kidney disease (CKD) is closely associated with disturbances in the composition of gut microbiota, it remains unclear the importance of gut microbiota in the onset and development of CKD. For the purpose of untangling the role of gut microbiota in CKD, gut microbiota was depleted with a pool of broad-spectrum antibiotics in mice submitted to unilateral ureteral obstruction (UUO).

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Mesenchymal stromal cells (MSCs) can generate immunological tolerance due to their regulatory activity in many immune cells. Extracellular vesicles (EVs) release is a pivotal mechanism by which MSCs exert their actions. In this study, we evaluate whether mesenchymal stromal cell extracellular vesicles (MSC-EVs) can modulate T cell response.

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Background: Sirolimus is approved for prophylaxis of organ rejection following renal transplantation. Rates of treatment-emergent adverse events (TEAEs) leading to sirolimus discontinuation differ geographically.

Methods: Rates of TEAEs, serious AEs (SAEs), and discontinuations were evaluated in 3 clinical trials of conversion from calcineurin inhibitors to sirolimus.

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Background: Severe Strongyloides stercoralis infection in kidney transplant recipients is associated with considerable morbidity and mortality, although little is known about the risk factors for such infection.

Methodology/principal Findings: This was a retrospective, multicenter, case-control study in which we assessed the risk factors for and clinical outcomes of severe S. stercoralis infections in kidney transplant recipients in Brazil.

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Background: The results of kidney transplantation are impacted by the categories of events responsible for patient death and graft failure. The objective of this study was to evaluate the causes of death and graft failure and outcomes after graft failure among kidney transplant recipients.

Methodology: A retrospective cohort study was conducted with 944 patients who underwent kidney transplantation.

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While calcineurin inhibitors (CNIs) are effective for preventing acute rejection in kidney transplant recipients, long-term use may cause chronic kidney injury and is associated with increased risks of cardiovascular events, cancer, and infection-associated death. Immunosuppression strategies are needed to balance risks of acute and subclinical rejection with long-term benefits of improved kidney function. Sirolimus, an inhibitor of mammalian target of rapamycin, is used for immunosuppression in kidney transplantation.

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The indirect effects of cytomegalovirus (CMV) viremia can be related to chronic changes in renal allograft structure, but its real impact in early and late graft function remains speculative. A total of 159 patients undergoing renal transplantation using a preemptive therapeutic strategy to prevent CMV disease were included in the present study. The patients were prospectively followed, with serial measurements of urinary retinol-binding protein (uRBP), a marker of proximal tubule injury.

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Acute kidney injury (AKI) is considered an inflammatory disease in which toll-like receptors (TLRs) signaling pathways play an important role. The activation of TLRs results in production of several inflammatory cytokines leading to further renal damage. In contrast, TLRs are key players on autophagy induction, which is associated with a protective function on cisplatin-induced AKI.

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Objectives: To evaluate the safety and efficacy of endovascular intervention with angioplasty and stent placement in patients with transplant renal artery stenosis.

Methods: All patients diagnosed with transplant renal artery stenosis and graft dysfunction or resistant systemic hypertension who underwent endovascular treatment with stenting from February 2011 to April 2016 were included in this study. The primary endpoint was clinical success, and the secondary endpoints were technical success, complication rate and stent patency.

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Delayed graft function (DGF) is very high in our center (70%-80%), and we usually receive a kidney for transplant after more than 22 hours of static cold ischemia time (CIT). Also, there is an inadequate care of the donors, contributing to a high rate of DGF. We decided to test whether machine perfusion (MP) after a CIT improved the outcome of our transplant patients.

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Mesenchymal stromal cells (MSCs) are multipotent cells with abilities to exert immunosuppressive response promoting tissue repair. Studies have shown that MSCs can secrete extracellular vesicles (MVs-MSCs) with similar regulatory functions to the parental cells. Furthermore, strong evidence suggesting that MVs-MSCs can modulate several immune cells (i.

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Mesenchymal stromal cells (MSCs) orchestrate tissue repair by releasing cell-derived microvesicles (MVs), which, presumably by small RNA species, modulate global gene expression. The knowledge of miRNA/mRNA signatures linked to a reparative status may elucidate some of the molecular events associated with MSC protection. Here, we used a model of cisplatin-induced kidney injury (acute kidney injury) to assess how MSCs or MVs could restore tissue function.

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Background: Proximal tubular dysfunction (PTD) is associated with a decreased long-term graft survival in renal transplant patients and can be detected by the elevation of urinary tubular proteins. This study investigated transcriptional changes in biopsies from renal transplant patients with PTD to disclose molecular mechanisms underlying graft injury and functional recovery.

Methods: Thirty-three renal transplant patients with high urinary levels of retinol-binding protein, a biomarker of PTD, were enrolled in the study.

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Aim: The role of post-reperfusion biopsy findings as a predictor of early and long-term graft function and survival is still a target of research.

Methods: We analyzed data from 136 post-reperfusion biopsies performed in deceased donor renal transplanted patients from November 2008 to May 2012. We analyzed the presence of acute tubular necrosis (ATN), arteriolar hyalinosis (AH), intimal thickness (IT), interstitial fibrosis (IF) and glomerulosclerosis (GS).

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Acute and chronic kidney injuries (AKI and CKI) constitute syndromes responsible for a large part of renal failures, and are today still associated with high mortality rates. Given the lack of more effective therapies, there has been intense focus on the use stem cells for organ protective and regenerative effects. Mesenchymal stem cells (MSCs) have shown great potential in the treatment of various diseases of immune character, although there is still debate on its mechanism of action.

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Aim: Experimental autoimmune encephalomyelitis (EAE) is a CD4(+)-mediated autoimmune pathology of the central nervous system (CNS) that is used as a model for the study of the human neuroinflammatory disease, multiple sclerosis. During the development of EAE, auto-reactive Th1 and Th17 CD4(+) T cells infiltrate the CNS promoting inflammatory cells recruitment, focal inflammation and tissue destruction. In this sense, statins, agents used to lower lipid levels, have recently shown to exert interesting immunomodulatory function.

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Given the shortage of organs transplantation, some strategies have been adopted by the transplant community to increase the supply of organs. One strategy is the use of expanded criteria for donors, that is, donors aged >60 years or 50 and 59 years, and meeting two or more of the following criteria: history of hypertension, terminal serum creatinine >1.5mg/dL, and stroke as the donor´s cause of death.

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