Delayed Graft Function Under the Microscope: Surveillance Biopsies in Kidney Transplantation.

Delayed graft function (DGF) is a common complication of kidney transplantation and frequently leads to the necessity of surveillance biopsies. The purpose of this study is to describe the histological findings in surveillance biopsies of deceased donor kidney transplant recipients and evaluate the risk factors for graft outcomes. This is a monocentric, retrospective study including kidney transplant recipients that underwent a graft biopsy during the DGF period between January 2006 and July 2019. 356 biopsies were performed in 335 deceased donor transplant recipients. Biopsies were analyzed according to the Banff classification. The main histological findings were: acute tubular necrosis in 150 biopsies (42.1%), acute rejection in 96 biopsies (26.9%), and borderline findings in 91 biopsies (25.5%). In the multivariate analysis, recipient age (p = 0.028) and DGF duration (p = 0.005) were associated with rejection, antibody-induction with anti-thymocyte globulin (ATG) was protective (p = 0.001). The occurrence of rejection was associated with lower death-censored graft survival (log-rank; p = 0.009). Surveillance biopsies of kidney grafts experiencing DGF remain an essential tool for the care of kidney transplant recipients. The recipient's age and duration of DGF are independent risk factors for acute rejection, while antibody-induction therapy with ATG is associated with protection from its occurrence.

Long-term effects of delayed graft function duration on function and survival of deceased donor kidney transplants / Efeitos de longo prazo da duração da função tardia do enxerto sobre a função e sobrevida de transplantes renais com doadores falecidos

Abstract Introduction: Delayed graft function (DGF) is a frequent complication after deceased donor kidney transplantation with an impact on the prognosis of the transplant. Despite this, long-term impact of DGF on graft function after deceased donor kidney transplantation has not been properly evaluated. Objective: The main objective of this study was to evaluate risk factors for DGF and the impact of its occurrence and length on graft survival and function. Methods: A retrospective cohort study was performed in 517 kidney transplant recipients who received a deceased donor organ between January 2008 and December 2013. Results: The incidence of DGF was 69.3% and it was independently associated with donor's final serum creatinine and age, cold ischemia time, use of antibody induction therapy and recipient's diabetes mellitus. The occurrence of DGF was also associated with a higher incidence of Banff ≥ 1A grade acute rejection (P = 0.017), lower graft function up to six years after transplantation and lower death-censored graft survival at 1 and 5 years (P < 0.05). DGF period longer than 14 days was associated with higher incidence of death-censored graft loss (P = 0.038) and poorer graft function (P < 0.001). No differences were found in patient survival. Conclusions: The occurrence of DGF has a long-lasting detrimental impact on graft function and survival and this impact is even more pronounced when DGF lasts longer than two weeks.

Resumo Introdução: A função tardia do enxerto (FTE) é uma complicação frequente após transplantes renais com doadores falecidos com repercussões sobre o prognóstico do transplante. Contudo, o impacto a longo prazo da FTE sobre a função do enxerto após transplante renal com doador falecido não foi avaliado adequadamente. Objetivo: O principal objetivo do presente estudo foi avaliar os fatores de risco para FTE e o impacto de sua ocorrência e duração na sobrevida e função do enxerto. Métodos: O presente estudo observacional retrospectivo incluiu 517 receptores de transplante renal que receberam órgãos de doadores falecidos entre janeiro de 2008 e dezembro de 2013. Resultados: A incidência de FTE foi de 69,3%. Foi identificada associação independente entre FTE e creatinina sérica final e idade do doador, tempo de isquemia fria, uso de terapia de indução com anticorpos e diabetes mellitus do receptor. A ocorrência de FTE também foi associada a incidência mais elevada de rejeição aguda com classificação de Banff ≥ 1 A (P = 0,017), função reduzida do enxerto até seis anos após o transplante e menor sobrevida do enxerto censurada para óbito em 1 e 5 anos (P <0,05). Períodos de FTE superiores a 14 dias foram associados a maior incidência de perda do enxerto censurada para óbito (P = 0,038) e pior função do enxerto (P <0,001). Não foram identificadas diferenças de sobrevida nos pacientes. Conclusões: A ocorrência de FTE traz prejuízos de longa duração à função e sobrevida do enxerto. Tal impacto é ainda mais pronunciado quando a FTE persiste por mais de duas semanas.

Long-term effects of delayed graft function duration on function and survival of deceased donor kidney transplants.

INTRODUCTION: Delayed graft function (DGF) is a frequent complication after deceased donor kidney transplantation with an impact on the prognosis of the transplant. Despite this, long-term impact of DGF on graft function after deceased donor kidney transplantation has not been properly evaluated. OBJECTIVE: The main objective of this study was to evaluate risk factors for DGF and the impact of its occurrence and length on graft survival and function. METHODS: A retrospective cohort study was performed in 517 kidney transplant recipients who received a deceased donor organ between January 2008 and December 2013. RESULTS: The incidence of DGF was 69.3% and it was independently associated with donor's final serum creatinine and age, cold ischemia time, use of antibody induction therapy and recipient's diabetes mellitus. The occurrence of DGF was also associated with a higher incidence of Banff ≥ 1A grade acute rejection (P = 0.017), lower graft function up to six years after transplantation and lower death-censored graft survival at 1 and 5 years (P < 0.05). DGF period longer than 14 days was associated with higher incidence of death-censored graft loss (P = 0.038) and poorer graft function (P < 0.001). No differences were found in patient survival. CONCLUSIONS: The occurrence of DGF has a long-lasting detrimental impact on graft function and survival and this impact is even more pronounced when DGF lasts longer than two weeks.