Temporal Reduction in COVID-19-Associated Fatality Among Kidney Transplant Recipients: The Brazilian COVID-19 Registry Cohort Study.

Data from the general population suggest that fatality rates declined during the course of the pandemic. This analysis, using data extracted from the Brazilian Kidney Transplant COVID-19 Registry, seeks to determine fatality rates over time since the index case on March 3rd, 2020. Data from hospitalized patients with RT-PCR positive SARS-CoV-2 infection from March to August 2020 (35 sites, 878 patients) were compared using trend tests according to quartiles (Q1: <72 days; Q2: 72-104 days; Q3: 105-140 days; Q4: >140 days after the index case). The 28-day fatality decreased from 29.5% (Q1) to 18.8% (Q4) (pfor-trend = 0.004). In multivariable analysis, patients diagnosed in Q4 showed a 35% reduced risk of death. The trend of reducing fatality was associated with a lower number of comorbidities (20.7-10.6%, p for-trend = 0.002), younger age (55-53 years, pfor-trend = 0.062), and better baseline renal function (43.6-47.7 ml/min/1.73 m2, pfor-trend = 0.060), and were confirmed by multivariable analysis. The proportion of patients presenting dyspnea (pfor-trend = 0.001) and hypoxemia (pfor-trend < 0.001) at diagnosis, and requiring intensive care was also found reduced (pfor-trend = 0.038). Despite possible confounding variables and time-dependent sampling differences, we conclude that COVID-19-associated fatality decreased over time. Differences in demographics, clinical presentation, and treatment options might be involved.

Angiotensin-Converting Enzyme 2 in the Pathogenesis of Renal Abnormalities Observed in COVID-19 Patients.

Coronavirus disease 2019 (COVID-19) was first reported in late December 2019 in Wuhan, China. The etiological agent of this disease is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the high transmissibility of the virus led to its rapid global spread and a major pandemic (ongoing at the time of writing this review). The clinical manifestations of COVID-19 can vary widely from non-evident or minor symptoms to severe acute respiratory syndrome and multi-organ damage, causing death. Acute kidney injury (AKI) has been recognized as a common complication of COVID-19 and in many cases, kidney replacement therapy (KRT) is required. The presence of kidney abnormalities on hospital admission and the development of AKI are related to a more severe presentation of COVID-19 with higher mortality rate. The high transmissibility and the broad spectrum of clinical manifestations of COVID-19 are in part due to the high affinity of SARS-CoV-2 for its receptor, angiotensin (Ang)-converting enzyme 2 (ACE2), which is widely expressed in human organs and is especially abundant in the kidneys. A debate on the role of ACE2 in the infectivity and pathogenesis of COVID-19 has emerged: Does the high expression of ACE2 promotes higher infectivity and more severe clinical manifestations or does the interaction of SARS-CoV-2 with ACE2 reduce the bioavailability of the enzyme, depleting its biological activity, which is closely related to two important physiological systems, the renin-angiotensin system (RAS) and the kallikrein-kinin system (KKS), thereby further contributing to pathogenesis. In this review, we discuss the dual role of ACE2 in the infectivity and pathogenesis of COVID-19, highlighting the effects of COVID-19-induced ACE2 depletion in the renal physiology and how it may lead to kidney injury. The ACE2 downstream regulation of KKS, that usually receives less attention, is discussed. Also, a detailed discussion on how the triad of symptoms (respiratory, inflammatory, and coagulation symptoms) of COVID-19 can indirectly promote renal injury is primary aborded.

Improving data quality in liquid chromatography-mass spectrometry metabolomics of human urine.

Signal variation is a common drawback in untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS), mainly due to the complexity of biological matrices and reduced sample preparation, which results in the accumulation of sample components in the column and the ion source. Here we propose a simple, easy to implement approach to improve data quality in untargeted metabolomics by LC-MS. This approach involves the use of a divert valve to direct the column effluent to waste at the beginning of the chromatographic run and during column cleanup and equilibration, in combination with longer column cleanups in between injections. Our approach was tested using urine samples collected from patients after renal transplantation. Analytical responses were contrasted before and after introducing these modifications by analyzing a batch of untargeted metabolomics data. A significant improvement in peak area repeatability was observed for the quality controls, with relative standard deviations (RSDs) for several metabolites decreasing from ∼60% to ∼10% when our approach was introduced. Similarly, RSDs of peak areas for internal standards improved from ∼40% to ∼10%. Furthermore, calibrant solutions were more consistent after introducing these modifications when comparing peak areas of solutions injected at the beginning and the end of each analytical sequence. Therefore, we recommend the use of a divert valve and extended column cleanup as a powerful strategy to improve data quality in untargeted metabolomics, especially for very complex types of samples where minimum sample preparation is required, such as in this untargeted metabolomics study with urine from renal transplanted patients.

Urological Complications Associated With Pyeloureterostomy Without Ipsilateral Nephrectomy in Renal Transplant Recipients.

Background: The implications of ligating the native ureter without ipsilateral nephrectomy after primary kidney transplant pyeloureterostomy (PU) have been described previously. Methods: This single-center retrospective cohort study including 4,215 kidney transplants performed between February 2010 and December 2014, analyzed urological complications following primary (P-PU) and secondary (S-PU) pyeloureterostomy used to treat urological leaks (UL-PU) and ureteral stenosis (US-PU) without concomitant ipsilateral nephrectomy, in a large cohort of patients. Results: There were 495 (11.7%) pyeloureterostomy with native ureter ligation without nephrectomy, 409 P-PU (82.6%) and 86 S-PU (17.4%), of which 76 were UL-PU and 10 were US-PU. The median follow-up was 33.8 months. The incidence of native ipsilateral kidney complications requiring nephrectomy was 2.02% (n = 10). Urinary leak was diagnosed in 3.6% of patients after P-UP and 9.2% after UL-PU. Ureteral stenosis was diagnosed in 1.7% of patients after P-UP, 3.9% after UL-PU and 10% after US-PU. Conclusion: This cohort analysis suggests that native ureter ligation during pyeloureterostomy without native nephrectomy is associated with low incidence of clinically indicated ipsilateral native nephrectomy. Caution and awareness should be emphasized in patients with history of ADPKD and neurogenic augmented bladders.

Immunosuppressive Drug-Associated Adverse Event Profiles in De Novo Kidney Transplant Recipients Receiving Everolimus and Reduced Tacrolimus Doses.

BACKGROUND: The safety of immunosuppressive regimens is influenced by the induction agent, maintenance drug combination, and prophylactic strategy for cytomegalovirus (CMV) infection. Herein, this safety analysis compares rabbit antithymocyte globulin (r-ATG) or basiliximab (BAS) combined with everolimus (EVR) versus BAS combined with mycophenolate sodium (MPS) in kidney transplant recipients receiving tacrolimus, prednisone, and preemptive CMV therapy. METHODS: In this single-center, prospective, randomized study, adverse events (AEs), serious AEs (SAEs), viral infections, laboratory abnormalities, dose reductions, and temporary or permanent discontinuation of the immunosuppressant were compared among patients receiving r-ATG/EVR (n = 85), BAS/EVR (n = 102), and BAS/MPS (n = 101). RESULTS: A total of 2741 AEs and 344 SAEs were observed. There were no differences in the proportion of patients with at least one AE (96% versus 98% versus 96%, respectively; P > 0.05). The proportion of patients with at least one SAE was highest in the BAS/MPS group (33% versus 48% versus 69%, respectively; P < 0.05). This difference was due primarily to a high incidence of CMV infection in the BAS/MPS group (4.7% versus 10.8% versus 37.6%, respectively). The incidence of mild/moderate abnormalities in creatinine, cholesterol, and triglyceride levels was higher in both EVR groups. The cumulative freedom from dose reduction or treatment discontinuation due to an AE was higher in both EVR groups than in the BAS/MPS group (89.2% versus 92.8% versus 76.3%, respectively, P = 0.003). There was no difference in the incidence of biopsy-confirmed acute rejection (9.4% versus 18.6 versus 15.8%, respectively; P = 0.403). CONCLUSIONS: This analysis suggests that r-ATG induction combined with EVR is associated with a comparable incidence of acute rejection, lower incidence of CMV infection, and fewer changes in initial immunosuppressive regimen due to AEs in kidney transplant recipients receiving tacrolimus, prednisone, and preemptive CMV therapy.

Early Hospital Readmission (EHR) in kidney transplantation: a review article / Readmissão Hospitalar Precoce no transplante renal: artigo de revisão

Abstract Early hospital readmission (EHR), defined as all readmissions within 30 days of initial hospital discharge, is a health care quality measure. It is influenced by the demographic characteristics of the population at risk, the multidisciplinary approach for hospital discharge, the access, coverage, and comprehensiveness of the health care system, and reimbursement policies. EHR is associated with higher morbidity, mortality, and increased health care costs. Monitoring EHR enables the identification of hospital and outpatient healthcare weaknesses and the implementation of corrective interventions. Among kidney transplant recipients in the USA, EHR ranges between 18 and 47%, and is associated with one-year increased mortality and graft loss. One study in Brazil showed an incidence of 19.8% of EHR. The main causes of readmission were infections and surgical and metabolic complications. Strategies to reduce early hospital readmission are therefore essential and should consider the local factors, including socio-economic conditions, epidemiology and endemic diseases, and mobility.

Resumo A Readmissão Hospitalar Precoce (RH), definida como todas as readmissões dentro de 30 dias após a alta hospitalar inicial, é uma métrica da qualidade hospitalar. É influenciada pelas características demográficas da população em risco, pela abordagem multidisciplinar da alta hospitalar inicial, pelo acesso, pela cobertura e pela abrangência do Sistema de Saúde e pelas políticas de reembolso. A readmissão hospitalar precoce está associada a maior morbidade, mortalidade e aumento dos custos com saúde. O monitoramento da RH permite a identificação das fragilidades hospitalares e ambulatoriais e a implementação de intervenções corretivas. Entre os receptores de transplante renal nos EUA, a RH varia entre 18% e 47% e está associada a maior mortalidade e perda do enxerto no primeiro ano do transplante. Um estudo no Brasil mostrou uma incidência de 19,8% de RH. As principais causas de readmissão foram infecções e complicações cirúrgicas e metabólicas. As estratégias para reduzir a readmissão hospitalar precoce são, portanto, essenciais e devem considerar o ambiente local, incluindo condições socioeconômicas, epidemiologia local, doenças e mobilidade endêmicas.

Early Hospital Readmission (EHR) in kidney transplantation: a review article.

Early hospital readmission (EHR), defined as all readmissions within 30 days of initial hospital discharge, is a health care quality measure. It is influenced by the demographic characteristics of the population at risk, the multidisciplinary approach for hospital discharge, the access, coverage, and comprehensiveness of the health care system, and reimbursement policies. EHR is associated with higher morbidity, mortality, and increased health care costs. Monitoring EHR enables the identification of hospital and outpatient healthcare weaknesses and the implementation of corrective interventions. Among kidney transplant recipients in the USA, EHR ranges between 18 and 47%, and is associated with one-year increased mortality and graft loss. One study in Brazil showed an incidence of 19.8% of EHR. The main causes of readmission were infections and surgical and metabolic complications. Strategies to reduce early hospital readmission are therefore essential and should consider the local factors, including socio-economic conditions, epidemiology and endemic diseases, and mobility.

Simultaneous Determination of Everolimus, Sirolimus, Tacrolimus, and Cyclosporine-A by Mass Spectrometry.

Measurement of immunosuppressive drug concentrations cyclosporine A (CyA), tacrolimus (TAC), sirolimus (SIR), and everolimus (EVE) in blood is an important application of therapeutic drug monitoring. These immunosuppressive agents are used in combined regimens and nowadays the liquid chromatography and tandem mass spectrometry is the best option for simultaneous analysis of these drugs in one short run. We developed an liquid chromatography and tandem mass spectrometry methodology in-house to measure the combination of immunosuppressants in a single blood sample from transplant patients in Brazil. We analyzed 235 combinations of 4 immunosuppressive drugs in patient blood to validate this study. The measuring ranges were 9 to 1000 ng/mL for CyA and 2 to 50 ng/mL for TAC, SIR, and EVE. Accuracy of the method was between 83.87% and 126.6% (coefficient of determination [r2] > 0.995). Validation of variation was ≤15% for lower limit of quantification. In our analysis 20% of patients treated with EVE showed concentration range of 6 to 6.9 ng/mL, 28% of patients treated with SIR showed a concentration range of 4 to 4.9 ng/mL to TAC, 22% of patients showed concentration range of 5 to 5.9 ng/mL, and finally 50% of patients treated with CyA showed concentration range of 20 to 30 ng/mL. Our routine laboratory was able to implement this new methodology in-house to measure simultaneous CyA, TAC, SIR, and EVE in a single blood sample from transplant patients with a sensibility and rapid quantification analysis.

Clinical and pathological features of thrombotic microangiopathy influencing long-term kidney transplant outcomes.

INTRODUCTION: Thrombotic microangiopathy (TMA) in post-transplant setting has heterogeneous clinical manifestations. METHODS: We retrospectively studied data of 89 patients with post-transplant TMA, which was characterized by thrombi in at least one glomerulus and/or arteriole. Systemic TMA was defined by thrombocytopenia and microangiopathic anemia and early onset TMA, when occurred less than 90 days post transplant. RESULTS: The cumulative incidence was 0.93%. The majority of the recipients were young (mean age 39 years), female (52%) and Caucasian (48%) with primary kidney disease of unknown etiology (37%). Early TMA occurred in 51% of the patients and systemic TMA, in 25%. Underlying precipitating factors were: infection (54%), acute rejection (34%), calcineurin inhibitor toxicity (13%) and pregnancy (3%). 18% of the patients had several triggers. Glomerular TMA was observed in 50% of the biopsies and endothelial cell activation, in 61%. The 1-year patient survival was 97% and corresponding graft survival, 66%. Allograft survival was inferior when acute antibody mediated rejection (ABMR) occurred (with 41%; without 70%, p = 0.01), however no differences were determined by hemolysis, time of onset, thrombi location or endothelial cell activation. CONCLUSIONS: Our results suggest that post-transplant TMA is a rare but severe condition, regardless of its clinical and histological presentation, mainly when associated to ABMR.

Use of mTOR inhibitor as prophylaxis for cytomegalovirus disease after kidney transplantation: A natural experiment.

OBJECTIVES: To describe the incidence of cytomegalovirus (CMV) infection/disease in kidney transplant recipients receiving an mTOR-inhibitor-containing immunosuppressive regimen without prophylactic CMV treatment. METHODS: This single-center retrospective cohort analysis included all de novo kidney transplant recipients (09/15/2015-07/31/2017) receiving 3 mg/kg single dose of rabbit antithymocyte globulin induction, tacrolimus, everolimus, and prednisone. Preemptive therapy was initiated only in patients deemed at higher risk for CMV infection: (a) D+/R- CMV patients; (b) after treatment for acute rejection (ARt); and (c) after everolimus discontinuation (EVRd). RESULTS: Of 230 patients, there were no episodes of CMV disease among 217 (94%) without criteria to initiate preemptive therapy. Of 77 (33.5%) patients initiating preemptive therapy, 13 were D+/R-, 30 were ARt, and 34 were EVRd. The overall incidence of first CMV infection/disease was 6% (46.1% in D+/R-, 13.3% ARt [all patients had also discontinued everolimus], and 11.8% after early [<90 days] EVRd). The incidence of biopsy-proven acute rejection was 5.6%, and median glomerular filtration rate at month 12 was 47 mL/min/1.73m2 . One-year patient and death-censored graft survivals were 97.4% and 98.1%. CONCLUSION: This study suggests that everolimus-containing immunosuppressive regimen reduces the need for preventive strategies for CMV infection in the majority of kidney transplant recipients, reducing antiviral drug-associated toxicities and healthcare-related expenditures.

Prospective randomized study comparing everolimus and mycophenolate sodium in de novo kidney transplant recipients from expanded criteria deceased donor.

The optimal immunosuppressive regimen for recipients of expanded criteria donor (ECD) kidneys has not been identified. In this single-center study, 171 recipients of ECD kidney transplants were randomized to receive antithymocyte globulin induction, and delayed introduction of reduced dose tacrolimus, prednisone and everolimus (r-ATG/EVR, n = 88), or mycophenolate (r-ATG/MPS, n = 83). No cytomegalovirus (CMV) pharmacological prophylaxis was used. The primary endpoint was the incidence of CMV infection/disease at 12 months. Secondary endpoints included treatment failure [first biopsy-proven acute rejection (BPAR), graft loss, or death] and safety. Patients treated with EVR showed a 89% risk reduction (13.6 vs. 71.6%; HR 0.11, 95% CI 0.06-0.220, P < 0.001) in the incidence of first CMV infection/disease. Incidences of BPAR (16% vs. 5%, P = 0.021), graft loss (11% vs. 1%, P = 0.008), death (10% vs. 1%, P = 0.013), and treatment discontinuation (40% vs. 28%, P = 0.12) were higher in the r-ATG/EVR, leading to premature study termination. Mean glomerular filtration rate was lower in r-ATG/EVR (31.8 ± 18.8 vs. 42.6 ± 14.9, P < 0.001). In recipients of ECD kidney transplants receiving no CMV pharmacological prophylaxis, the use of everolimus was associated with higher treatment failure compared with mycophenolate despite the significant reduction in the incidence of CMV infection/disease (ClinicalTrials.gov.NCT01895049).

Early hospital readmission after kidney transplantation under a public health care system.

Early hospital readmission (EHR) is associated with increased mortality after kidney transplantation. This is influenced by population demographics and the comprehensiveness of the healthcare system. We investigated the incidence and risk factors associated with EHR and 1-year patient and graft survivals. METHODS: We included all recipients of kidney transplant between 2011 and 2012. We excluded recipients younger than 18 years, retransplants and who died or lost the graft during the index hospital admission. RESULTS: Among 1175 recipients, the incidence of EHR was 26.6%. The main reasons for EHR were infection (67%), surgical complications (14%), and metabolic disturbances (11%). Independent risk factors associated with EHR were recipient age (OR = 1.95, 95% CI 1.46-2.63, P < 0.001), CMV serology negative (OR = 2.2, 95% CI 1.31-3.65, P = 0.003), use of rabbit anti-thymocyte globulin (OR = 2.06, 95% CI 1.33-3.13, P < 0.001), treatment for acute rejection during index hospitalization (OR = 1.68, 95% CI 1.15-2.47, P = 0.008), and length of stay (OR = 1.72, 95% CI 1.18-2.5, P = 0.005). Patient (88.8% vs 97.6%, P < 0.001) and death-censored graft (97.4% vs 99.0%, P < 0.001) survivals were inferior comparing patients with and without EHR. Conclusion EHR was independently associated with mortality (OR 4.01, 95% CI 2.13-7.54, P < 0.001), but its incidence and causes are directly related to the local characteristics of the population and healthcare system.

The influence of clinical, environmental, and socioeconomic factors on five-year patient survival after kidney transplantation / A influência de fatores clínicos, ambientais e socioeconômicos na sobrevida de cinco anos após o transplante renal

ABSTRACT Introduction: The risk of death after kidney transplant is associated with the age of the recipient, presence of comorbidities, socioeconomic status, local environmental characteristics and access to health care. Objective: To investigate the causes and risk factors associated with death during the first 5 years after kidney transplantation. Methods: This was a single-center, retrospective, matched case-control study. Results: Using a consecutive cohort of 1,873 kidney transplant recipients from January 1st 2007 to December 31st 2009, there were 162 deaths (case group), corresponding to 5-year patient survival of 91.4%. Of these deaths, 25% occurred during the first 3 months after transplant. The most prevalent cause of death was infectious (53%) followed by cardiovascular (24%). Risk factors associated with death were history of diabetes, dialysis type and time, unemployment, delayed graft function, number of visits to center, number of hospitalizations, and duration of hospital stay. After multivariate analysis, only time on dialysis, number of visits to center, and days in hospital were still associated with death. Patients who died had a non-significant higher number of treated acute rejection episodes (38% vs. 29%, p = 0.078), higher mean number of adverse events per patient (5.1 ± 3.8 vs. 3.8 ± 2.9, p = 0.194), and lower mean eGFR at 3 months (50.8 ± 25.1 vs. 56.7 ± 20.7, p = 0.137) and 48 months (45.9 ± 23.8 vs. 58.5 ± 20.2, p = 0.368). Conclusion: This analysis confirmed that in this population, infection is the leading cause of mortality over the first 5 years after kidney transplantation. Several demographic and socioeconomic risk factors were associated with death, most of which are not readily modifiable.

RESUMO Introdução: O risco de óbito após transplante renal está associado à idade do receptor, presença de comorbidades, condição socioeconômica, às características ambientais locais e ao acesso a serviços de atenção à saúde. Objetivo: Investigar as causas e fatores de risco associados ao óbito nos primeiros cinco anos após o transplante renal. Métodos: Este é um estudo unicêntrico retrospectivo com pareamento dos grupos caso e controle. Resultados: Em uma coorte consecutiva de 1.873 receptores de transplante renal atendidos de 1/1/2007 a 31/12/2009 foram registrados 162 óbitos (grupo caso), correspondendo a uma taxa de sobrevida após cinco anos de 91,4%. Dos óbitos registrados, 25% ocorreram nos primeiros três meses após o transplante. A causa de óbito mais prevalente foi infecção (53%), seguida de doença cardiovascular (24%). Os fatores de risco associados a mortalidade foram histórico de diabetes, tipo e tempo em diálise, desemprego, função tardia do enxerto, número de consultas, número de hospitalizações e tempo de internação hospitalar. Após análise multivariada, apenas o tempo em diálise, o número de consultas e dias de internação permaneceram associados a mortalidade. Os pacientes que foram a óbito tiveram um número não significativamente maior de tratamentos de episódios de rejeição aguda (38% vs. 29%; p = 0,078), maior número médio de eventos adversos por paciente (5,1 ± 3,8 vs. 3,8 ± 2,9; p = 0,194) e TFGe média mais baixa aos três meses (50,8 ± 25,1 vs. 56,7 ± 20,7; p = 0,137) e 48 meses (45,9 ± 23,8 vs. 58,5 ± 20,2; p = 0,368). Conclusão: A presente análise confirmou que nessa população, a infecção foi a principal causa de mortalidade nos primeiros cinco anos após transplante renal. Vários fatores de risco demográficos e socioeconômicos foram associados a mortalidade, a maioria não prontamente modificável.

The effect of anti-thymocyte globulin and everolimus on the kinetics of cytomegalovirus viral load in seropositive kidney transplant recipients without prophylaxis.

BACKGROUND: The use of mTOR inhibitors is associated with lower incidence of CMV infections but its effect on viral load has not been investigated. AIMS, MATERIALS AND METHODS: This post-hoc analysis included data from 273 CMV seropositive kidney transplant recipients randomized to receive anti-thymocyte globulin and everolimus (rAGT/TAC/EVR, n = 81), basiliximab and everolimus (BAS/TAC/EVR, n = 97) or basiliximab and mycophenolate (BAS/TAC/MPS, n = 95). All patients received tacrolimus (TAC) and corticosteroids. Preemptive CMV therapy based on weekly pp65 antigenemia test was used during the first 6 months. Blinded weekly CMV DNAemia was compared among the groups. RESULTS: The proportion of patients with undetectable CMV DNAemia (23.4% vs 56.7% vs 22.1%, P < .001) was higher in the BAS/TAC/EVR. The median number of study visits with positive CMV DNAemia (2.0 vs 0.0 vs 4.6, rATG/EVR vs BAS/MPS, P = .354; BAS/EVR vs BAS/MPS, P < .0001; rATG/EVR vs BAS/EVR, P < .001) were lower in the BAS/TAC/EVR. The proportion of patients with positive CMV DNAemia who were not treat for CMV infection/disease based on pp65 antigenemia was higher in rATG/TAC/EVR group (74.1% vs 36.1% vs 44.2%, P < .001) but mean CMV DNAemia was comparable to BAS/TAC/EVR and lower than BAS/TAC/MPS (8536 ± 15 899 vs 7975 ± 17 935 vs 16 965 ± 37 694 copies/mL, P < .05), respectively. The proportion of patients with CMV DNAemia below 5000 copies/mL was higher in patients receiving EVR (74.1% vs 83.5% vs 50.0%, P = .000), respectively. DISCUSSION AND CONCLUSION: These data suggest that mTOR inhibitors reduce the incidence of CMV infection by limiting CMV viral replication.

Ureterocalicostomy with lower pole nephrectomy in a renal transplant: A case report.

As the number of kidney transplants continues to rise, so does the number and complexities of surgical-related complications, which may be associated with increased morbidity and potentially graft loss. Ureteral stenosis, the most prevalent urological complication, may require diverse techniques for surgical correction depending on several recipient and graft abnormalities. Here we report the surgical and clinical outcomes of a 62-year-old man with a posttransplant pyeloureterostomy stricture successfully treated with ureterocalicostomy after a lower pole nephrectomy. Although the resection of renal parenchyma may prevent a stenosis recurrence, surgeons can be reluctant to use this strategy due to the possible negative impact on renal function. We highlight some key steps of the surgical technique to prevent unnecessary allograft lesion and present short-term outcomes, suggesting that this rarely described procedure is a safe and effective alternative treatment for kidney transplant recipients with pyeloureterostomy stenosis.

Influence of ABCC2, CYP2C8, and CYP2J2 polymorphisms on tacrolimus and mycophenolate sodium-based treatment in brazilian kidney transplant recipients

STUDY OBJECTIVE: To investigate the influence of single nucleotide polymorphisms (SNPs) in genes encoding metabolizing enzymes (CYP2C8, CYP2J2, and UGT2B7) and transporters (ABCC2 and ABCG2) on dose and dose-adjusted trough blood concentrations (C:D ratio), clinical outcomes, and occurrence of adverse events of tacrolimus and mycophenolate sodium in Brazilian kidney transplant recipients. DESIGN: Pharmacogenetic analysis of patients enrolled in a previously published study. PATIENTS: One hundred forty-eight adult kidney transplant recipients treated with tacrolimus, enteric-coated mycophenolate sodium, and prednisone for 90 days posttransplantation.MEASUREMENTS AND MAIN RESULTS:ABCC2 c.-24C>T and c.3972C>T, ABCG2 c.421C>A, CYP2C8*3, CYP2J2 c.-76G>T, and UGT2B7 c.372A>G SNPs were determined by real-time polymerase chain reaction. The CYP3A5*3C SNP data were used to eliminate the confounding effect of this variant on the results. ABCC2 c.3972T allele carriers showed higher tacrolimus C:D values than did carriers of the c.3972CC genotype. The CYP2C8*3 variant was also associated with slightly higher tacrolimus C:D values and higher estimated glomerular filtration rate but only in CYP3A5-nonexpressing patients (CYP3A5*3C/*3C carriers). None of the SNPs were associated with mycophenolate sodium dose or episodes of biopsy-confirmed acute rejection or delayed graft function. The CYP2J2 c.-76T allele was associated with increased risk for treatment-induced nausea and/or vomiting (OR: 5.30, 95% confidence interval 1.49-18.79, p<0.05)...

Randomized Trial of Machine Perfusion Versus Cold Storage in Recipients of Deceased Donor Kidney Transplants With High Incidence of Delayed Graft Function

BACKGROUND: This study compared the use of static cold storage versus continuous hypothermic machine perfusion in a cohort of kidney transplant recipients at high risk for delayed graft function (DGF). METHODS: In this national, multicenter, and controlled trial, 80 pairs of kidneys recovered from brain-dead deceased donors were randomized to cold storage or machine perfusion, transplanted, and followed up for 12 months. The primary endpoint was the incidence of DGF. Secondary endpoints included the duration of DGF, hospital stay, primary nonfunction, estimated glomerular filtration rate, acute rejection, and allograft and patient survivals. RESULTS: Mean cold ischemia time was high but not different between the 2 groups (25.6 ± 6.6 hours vs 25.05 ± 6.3 hours, 0.937). The incidence of DGF was lower in the machine perfusion compared with cold storage group (61% vs. 45%, P = 0.031). Machine perfusion was independently associated with a reduced risk of DGF (odds ratio, 0.49; 95% confidence interval, 0.26-0.95). Mean estimated glomerular filtration rate tended to be higher at day 28 (40.6 ± 19.9 mL/min per 1.73 m2 vs 49.0 ± 26.9 mL/min per 1.73 m2; P = 0.262) and 1 year (48.3 ± 19.8 mL/min per 1.73 m2 vs 54.4 ± 28.6 mL/min per 1.73 m2; P = 0.201) in the machine perfusion group. No differences in the incidence of acute rejection, primary nonfunction (0% vs 2.5%), graft loss (7.5% vs 10%), or death (8.8% vs 6.3%) were observed...

O contexto do transplante renal no Brasil e sua disparidade geográfica / Kidney transplantation in Brazil and its geographic disparity

O Sistema Nacional de Transplantes (SNT) Brasileiro coordena e regulamenta o, provavelmente, maior programa de transplantes públicos do mundo. Desde o seu estabelecimento, em 1997, o número de transplantes renais aumentou de 920 (5,8 pmp), em 1988, para 4.630 (24,1 pmp), em 2010. Esse crescimento foi primariamente devido ao aumento no número de doadores efetivos (de 1,8 pmp em 1998 para 9,3 pmp em 2010), com aumento correspondente no número de rins transplantados de doadores falecidos (3,8 pmp em 1999 versus 9,9 pmp em 2010). O número de rins transplantados com órgãos de doadores vivos não aumentou significativamente, 1.065 (6,7 pmp), em 1998, para 1.641 (8,6 pmp), em 2010, tanto em consequência do melhor desempenho do programa de doadores falecidos, como talvez também devido a mais restrita regulamentação, permitindo apenas doação entre doadores vivos relacionados. De 2000 a 2009, a idade média dos doadores vivos aumentou de 40 para 45 anos, e a dos doadores falecidos, de 33 para 41 anos, com eventos cerebrovasculares sendo responsáveis por 50 por cento dos episódios de óbito atualmente. Existem disparidades geográficas evidentes nos desempenhos entre as 5 regiões nacionais. Enquanto o estado de São Paulo ocupa a primeira posição em doação e captação de órgãos (22,5 pmp), alguns estados da região Norte apresentam pequena ou nenhuma atividade de transplante. Essas disparidades estão diretamente relacionadas à densidade populacional regional, ao produto interno bruto e ao número de médicos com treinamento em transplante. A avaliação inicial de desfechos clínicos robustos não indica diferenças nas sobrevidas do enxerto em comparação com as observadas nos EUA e na Europa. A etnia e o tempo em diálise, mas não o tipo de imunossupressão, apresentam influência decisiva nos desfechos medidos. A regulamentação nacional da pesquisa clínica foi implementada a partir de 1996, permitindo a participação de centros brasileiros em numerosos estudos clínicos nacionais e internacionais para o desenvolvimento de regimes imunossupressores. Acompanhando o desafio de atenuar as disparidades regionais no acesso ao transplante, o sistema pode ser aperfeiçoado pela criação de um registro nacional para receptores de transplante e de doadores vivos de rins e também pela promoção de estudos clínicos e experimentais voltados a melhor compreender a resposta imune relacionada ao transplante em nossa população.

The Brazilian National Transplantation System coordinates and regulates perhaps the largest public transplantation program worldwide. Since its implementation in 1997, the number of kidney transplantations increased from 920 (5.8 pmp) in 1998, to 4,630 (24.1 pmp) in 2010. This growth was primarily due to the increased number of effective donors (from 1.8 pmp in 1998 to 9.3 pmp in 2010), with a corresponding increased number of kidneys transplanted from deceased donors (3.8 pmp in 1999 versus 9.9 pmp in 2010).The number of kidney transplantations from living donors has not increased significantly, from 1,065 (6.7 pmp) in 1998 to 1,641 (8.6 pmp) in 2010, either as a consequence of the observed increase in the deceased donor program or perhaps because of strict government regulations allowing only transplantations from related donors. From 2000 to 2009, the mean age of living donors increased from 40 to 45 years, while it increased from 33 to 41 years for deceased donors, of whom roughly 50 percent die of stroke. There are clear regional disparities in transplantation performance across the national regions. While the state of São Paulo is ranked first in organ donation and recovery (22.5 pmp), some states of the Northern region have much poorer performances. These disparities are directly related to different regional population densities, gross domestic product distribution, and number of trained transplantation physicians. The initial evaluation of the centers with robust outcomes indicates no clear differences in graft survival in comparison with centers in the USA and Europe. Ethnicity and time on dialysis, but not the type of immunosuppressive regimen, decisively influence the measured outcomes. Since the implementation of national clinical research regulations in 1996, Brazilian centers have participated in a number of national and international collaborative trials for the development of immunosuppressive regimens. Besides the challenge of reducing the regional disparities related to access to transplantation, further improvements can be obtained by the creation of a national registry of the outcomes of transplanted patients and living donors, and also by the promotion of clinical and experimental studies to better understand the transplantation-related immune response of the Brazilian population.

Steroid or tacrolimus withdrawal in renal transplant recipients using sirolimus.

BACKGROUND: Calcineurin inhibitor (CNI) and steroid (ST) withdrawal are strategies under investigation to reduce long-term toxicities associated with current immunosuppressive regimens. We conducted a single center, prospective trial comparing the efficacy and safety of CNI or ST withdrawal in kidney transplant recipients receiving sirolimus-based immunosuppressive regimen. METHODS: Forty-seven recipients of first renal transplant with non-HLA-identical living donors received sirolimus (SRL), tacrolimus (TAC), and ST without induction therapy and were randomized to undergo ST (TAC/SRL group, n = 24) or TAC (SRL/ST group, n = 21) withdrawal 3 months after transplantation. Primary efficacy and safety endpoints were the incidence of biopsy-confirmed acute rejection (BCAR) and renal function at 12 months. RESULTS: No differences were observed in the incidence of BCAR (4.2% vs. 9.5%), graft (95.8% vs. 95.6%), and patient (95.8% vs. 95.6%) survivals or in renal function (60 ± 11.5 vs. 63.4 ± 10.5 ml/min, P = 0.361). Higher mean cholesterol concentration was observed in the SRL/ST group (191.9 ± 63.3 vs. 241.6 ± 61.5 mg/dl, P = 0.019). Treatment discontinuation due to adverse events occurred in 12.5% of patients in TAC/SRL group and 21.7% in SRL/ST group. CONCLUSION: Within this short period of observation, our study was unable to detect any significant difference in major transplant outcomes comparing CNI and ST elimination strategies.