Risk factors of transplant renal artery stenosis in kidney transplant recipients

Background: Transplant Renal Artery Stenosis (TRAS) is a recognized vascular complication after kidney transplantation. The overall risk predictors of TRAS are poorly understood. Methods: Retrospective analysis of patients with suspected TRAS (Doppler ultrasound PSV > 200 cm/s) who underwent angiographic study in a single center between 2007 and 2014. All patients with stenosis > 50% were considered with TRAS. Stenosis restricted in the body of the artery was also analyzed in a subgroup. Results: 274 patients were submitted to a renal angiography and 166 confirmed TRAS. TRAS group featured an older population (46.3 ± 11.0 vs. 40.9 ±14.2 years; p = 0.001), more frequent hypertensive nephropathy (30.1% vs. 15.7%; p = 0.01), higher incidence of Delayed Graft Function (DGF) (52.0% vs. 25.6%; p < 0.001) and longer Cold Ischemia Time (CIT) (21.5 ± 10.6 vs. 15.7 ± 12.9h; p < 0.001). In multivariable analyses, DGF (OR = 3.31; 95% CI 1.78‒6.30; p < 0.0001) was independent risk factors for TRAS. DM and CIT showed a tendency towards TRAS. The compound discriminatory capacity of the multivariable model (AUC = 0.775; 95% CI 0.718‒0.831) is significantly higher than systolic blood pressure and creatinine alone (AUC = 0.62; 95% CI 0.558–0.661). In body artery stenosis subgroup, DGF (OR = 1.86; 95% CI 1.04‒3.36; p = 0.03) and Diabetes Mellitus (DM) (OR = 2.44; 95% CI 1.31‒4.60; p = 0.005) were independent risk factors for TRAS. Conclusion: In our transplant population, DGF increased more than 3-fold the risk of TRAS. In the subgroup analysis, both DGF and DM increases the risk of body artery stenosis. The addition of other factors to hypertension and renal dysfunction may increase diagnostic accuracy. TRAS Trial registred: clinicaltrials.gov (n° NCT04225338)

Assessment of the association between Kidney Donor Profile Index, clinical outcomes, and immunosuppressive therapy in deceased donor kidney transplant recipients

Introdução: O impacto do KDPI na taxa de filtração glomerular estimada (TFGe) após 1 ano do transplante, bem como em outros desfechos do transplante renal precisam ser mais bem elucidados na população brasileira. Ainda, não há dados sobre qual terapia imunossupressora melhor se adaptaria aos rins com KDPI elevado. Objetivo: Avaliar o impacto do escore KDPI nos desfechos clínicos ao final de 12 meses após o transplante renal. Metodologia: Estudo do tipo coorte histórica, de centro único, com análise de 3.059 transplantes renais de doador falecido realizados entre 2013 e 2017, com seguimento por 12 meses. Os pacientes foram divididos em 4 grupos, conforme faixas de KDPI (0-35%; 36-50%; 51-85%; 86-100%). Foi utilizado o modelo de regressão logística para análise dos preditores para TFGe <50 ml/min/1,73m2 ao final de 1 ano. O cálculo da TFGe foi feito através da equação CKDEPI. Os desfechos clínicos ao final de 1 ano considerados foram: TFGe, infecção por CMV, rejeição aguda, perda do enxerto e óbito. Foi realizada uma subanálise no grupo KDPI >85% comparando os mesmos desfechos entre 3 grupos conforme o regime imunossupressor: micofenolato vs. azatioprina vs. inibidor da mTOR (imTOR). Resultados: A TFGe reduziu conforme aumento do KDPI (64,8 vs. 53,5 vs. 46,9 vs. 39,1 ml/min/1,73m2; p<0,001). Na análise multivariada, os preditores de TFGe <50 ml/min/1,73m2 foram KDPI >35%, tempo de isquemia fria (OR=1,015; IC95% 1,003- 1,027; p=0,012), infecção por CMV (OR=1,214; IC95% 1,037-1,420; p=0,016) e rejeição aguda (OR=2,411; IC95% 1,942-2,993; p<0,001). Na subanálise do regime imunossupressor nos receptores de rins com KDPI >85%, a incidência de infecção por CMV foi menor no grupo imTOR (64,5% vs. 36,0% vs. 8,2%; p<0,001). Porém, comparado ao MPS, o uso de imTOR foi associado a menor TFGe (39,8 vs. 39,5 vs. 28,3 ml/min/1,73m2; p=0,009) e maior incidência de rejeição aguda (15,8% vs. 50,0% vs. 23,3%; p<0,001). Conclusão: O escore KDPI apresentou capacidade em predizer o desfecho de TFGe ao final de 1 ano. O regime imunossupressor contendo imTOR deve ser utilizado com cautela nos receptores de rins com KDPI >85%.Introduction: The impact of KDPI on the estimated glomerular filtration rate (eGFR) 1 year after transplantation and other outcomes of kidney transplantation needs to be better elucidated in the Brazilian population. Still, there is no data on which immunosuppressive therapy would best suit kidneys with high KDPI. Objective: To assess the association of the KDPI on 1-year clinical outcomes after kidney transplantation. Methods: This single-center, historical cohort study analyzed 3,059 kidney transplants from deceased donors performed between 2013 and 2017, with a 12-month follow-up. Patients were divided into 4 groups, according to KDPI ranges (0- 35%; 36-50%; 51-85%; 86-100%). The logistic regression model was used to analyze the predictors for eGFR <50 ml/min/1.73m2 at the end of 1 year. Calculation of eGFR was performed using the CKD-EPI equation. The 1-year clinical outcomes were: eGFR, CMV infection, acute rejection, graft loss, and death. A sub-analysis was performed in the group KDPI >85%, comparing the same outcomes between 3 groups according to the immunosuppressive regimen: mycophenolate vs. azathioprine vs. mTOR inhibitor (imTOR). Results: eGFR decreased as KDPI increased (64.8 vs. 53.5 vs. 46.9 vs. 39.1 ml/min/1.73m2 ; p<0.001). In the multivariate analysis, the predictors of eGFR 35%, cold ischemia time (OR=1.015; 95%CI 1.003-1.027; p=0.012), CMV infection (OR=1.214; 95%CI 1.037-1.420; p=0.016) and acute rejection (OR=2.411; 95%CI 1.942-2.993; p<0.001). In the subanalysis of the immunosuppressive regimen in recipients with KDPI >85%, the incidence of CMV infection was lower in the imTOR group (64.5% vs. 36.0% vs. 8.2%; p<0.001). However, compared to MPS, the use of imTOR was associated with lower eGFR (39.8 vs. 39.5 vs. 28.3 ml/min/1.73m2 ; p=0.009) and a higher incidence of acute rejection (15.8% vs. 50.0% vs. 23.3%; p<0.001). Conclusion: The KDPI was able to predict the outcome of eGFR at the end of 1 year. ImTOR-containing immunosuppressive regimen should be used with caution in kidney recipients with KDPI >85%.Coordenação de Aperfeiçoamento Pessoal de Nível Superior (CAPES

A COVID-19 Overview from the Perspective of the Brazilian Kidney Transplantation Program

The Coronavirus disease 2019 (COVID-19) has significantly affected kidney transplantation activities around the world, thus resulting in a substantial decrease in both deceased and living transplants. This study presents a COVID-19 overview from the perspective of the Brazilian kidney transplant program by comparing its differences or similarities with the situations observed in other countries. During the first year of the pandemic, there was a 40% reduction in the number of kidney transplants worldwide. A similar scenario was observed in Brazil, which has the world’s largest public transplantation program. Beyond its effect on transplant activity, COVID-19 has influenced the outcomes of prevalent kidney transplant recipients (KTRs) because the prolonged use of immunosuppressive drugs and comorbidities increase the susceptibility of such patients to severe disease and death. In the pre-vaccination era, almost two-thirds of KTRs required hospitalization, more than 20% required dialysis, and one-third was admitted to the intensive care unit. In the pre-vaccination period in Brazil, 15% and 21% of KTRs died within 28 and 90 days of COVID-19 diagnosis, respectively. Although high vaccination coverage rates have altered the COVID-19 landscape in many populations, persistently low immunogenicity rates following sequential vaccination shots and the absence of targeted treatments for severe cases continue to classify KTRs as highly vulnerable, thus warranting significant concern

The Association Between Kidney Donor Profile Index and 1-y Graft Function

Background. The association between Kidney Donor Profile Index (KDPI) and 1-y estimated glomerular filtration rate (eGFR) with long-term kidney graft survival is well known. Yet, the association between KDPI and 1-y eGFR remains uncertain considering the several concurrent competing risk factors. Methods. This single-center, retrospective cohort study analyzed data from 3059 consecutive deceased donor kidney transplant recipients with a 1-y follow-up from January 2013 to December 2017. The aim was to determine the association between the KDPI strata (0%–35%, 36%–50%, 51%–85%, 86%–100%) and 1-y eGFR estimated by the CKD-EPI equation. Results. The incidence of delayed graft function (50.6% versus 59.3% versus 62.7% versus 62.0%; P 35%–50% (HR = 2.239, 95% CI = 1.862–2.691), and >51%–85% (HR = 2.871, 95% CI = 2.361–3.491), respectively. Other variables associated with a lower graft function were donor sex (HR male versus female = 0.896, 95% CI = 0.813–0.989) and cold ischemia time (HR for each hour = 1.011, 95% CI = 1.004–1.019). This association was sustained after the Poisson mediation analysis, including delayed graft function, cytomegalovirus, and acute rejection as mediators. Conclusions. In this cohort of deceased donor kidney recipients, KDPI, and cold ischemia time were the major independent risk factors associated with lower 1-y kidney function