Concordance of outcomes of pairs of kidneys transplanted into different recipients

Kidney transplant outcomes are influenced by donor characteristics, including age and gender. Additional donor factors, both genetic and environmental, also influence graft outcome. We aim to assess the strength of donor factors in determining kidney transplant outcomes by comparing paired kidneys from a single donor transplanted into different recipients. We conducted a retrospective cohort study of outcomes of pairs of deceased donor kidneys transplanted in our centre between 1992 and 2008. We examined the relationship within pairs for eGFR at 1 year and at 5 years post‐transplant using Spearman’s Correlation and the concordance of pairs of transplant kidneys with respect to the occurrence of acute rejection and delayed graft function (DGF). A total of 652 recipient pairs were analysed. Spearman’s correlation for eGFR was 0.36 at 1 year and 0.36 at 5 years post‐transplant. The incidence of DGF was 11%. The odds ratio of DGF occurring if the contralateral kidney had DGF was 5.99 (95% CI, 3.19–11.25). There is a significant degree of relationship within pairs of kidneys transplanted from the same donor for serum creatinine at 1 year and 5 years post‐transplant and also for the occurrence of delayed graft function.     

The relative influence of delayed graft function and acute rejection on renal transplant survival

Three hundred and eight cadaveric renal transplants were analysed to establish the effects of acute rejection in the first 90 days and delayed graft function (DGF) on graft outcome. There were 120 patients (39%) with no DGF and no rejection (group 1), 101 patients (33%) with rejection but no DGF (group 2), 41 patients (13%) with DGF but no rejection (group 3) and 46 patients (15%) with both rejection and DGF (group 4). The actuarial 4-year graft survival rates for groups 1,2,3 and 40.4%, respectively. The acute rejection rate was 101/221 (46%) in patients with initial graft function compared with 46/87 (53%) for those with DGF (²=1.02, P=0.31). Cox stepwise logistic regression analysis demonstrated that DGF was a more powerful predictive factor for poor graft survival (P=0.001) than acute rejection occurring in the first 90 days post-transplant (P=0.034). Further efforts at improving graft outcome should concentrate on reducing the incidence of DGF.     

Deceased donor renal transplantation--does side matter?

BACKGROUND: The aim of the present study was to determine whether the deceased donor kidney side (left or right kidney) was predictive of subsequent kidney transplant outcomes. METHODS: A retrospective analysis was undertaken of the left-right deceased donor kidney pairs transplanted into recipients with end-stage renal failure in Queensland between 1 April 1994 and 31 March 2004. RESULTS: A total of 201 left-right deceased donor kidney pairs were transplanted into 402 patients. The baseline characteristics of the recipients in the two groups were comparable, except that the patients receiving right kidneys had lower body mass indices and shorter cold ischaemic times. No differences were seen between the left and right kidney recipient groups with respect to operative duration (3.02 +/- 0.67 vs 3.12 +/- 0.72 h, P = 0.16), warm ischaemic time (0.62 +/- 0.18 vs 0.65 +/- 0.21, P = 0.09), delayed graft function (4 vs 6%, respectively, P = 0.26) or a composite vascular, haemorrhagic, ureteric and infective post-operative complication end-point (22 vs 22%, P = 0.90). Estimated glomerular filtration rates were almost identical at 1 month (52.7 +/- 39.6 vs 51.0 +/- 24.0 ml/min/1.73 m(2), P = 0.34) and remained comparable thereafter. Respective death-censored graft survival rates for left and right kidney recipients were 100 and 100% at 1 year, 99.4 and 96.4% at 3 years and 96.3 and 95.5% at 5 years, respectively (P = 0.67). CONCLUSIONS: Although left and right deceased donor kidneys present different operative challenges, the present results suggest that the probability of early post-operative complications, delayed graft function, impaired early and medium-term renal allograft function or death-censored graft failure is comparable between left and right kidney recipients.     

Risk factors for delayed kidney function and impact of delayed function on patient and graft survival in adult graft recipients

The influence of delayed kidney graft function on allograft outcome is described controversially in the literature. The aim of the study was to evaluate possible risk factors for delayed graft function (DGF) and investigate the impact of DGF on short- and long-term renal allograft function. Two groups were formed: the first one consisted of patients who gained immediate graft function (IGF) (n = 64) after transplantation and the second group included patients with DGF (n = 31; with at least one dialysis needed in first week after transplantation). The DGF group had a statistically significant longer duration on dialyses prior to transplantation (DGF 54 vs. IGF 33 months; p < 0.05), on average more frequently a re-transplantation (DGF 1.7 vs. IGF 1.3; p < 0.01), a longer re-anastomosis time (DGF 52.9 vs. 44.2 min; p < 0.01), a lower systolic (DGF 136 +/-24 mmHg vs. IGF 158 +/- 25; p < 0.001) and diastolic blood pressure (DGF 78 +/- 14 vs. IGF 89 +/- 16 mmHg; p < 0.01) at admission to the hospital and a higher serum (S)-creatinine at discharge (DGF 2.5 +/- 1.6 vs. IGF 1.6 +/- 0.4 mg/dL; p < 0.01). Prior to transplantation the DGF group had more often advanced vascular diseases (DGF 29.0 vs. IGF 12.5%; p < 0.01) and these patients incurred more frequently new ones during the next 3 yr after transplantation (DGF 22.6 vs. IGF 6.3%; p < 0.001). After 3 yr the graft survival tended to be lower in the DGF group (DGF 74.2 vs. IGF 84.4%; NS), but this difference was not statistically significant.     

Reduced graft function (with or without dialysis) vs immediate graft function--a comparison of long-term renal allograft survival.

BACKGROUND: Delayed graft function (DGF) is a common complication in cadaveric kidney transplants affecting graft outcome. However, the incidence of DGF differs widely between centres as its definition is very variable. The purpose of this study was to define a parameter for DGF and immediate graft function (IGF) and to compare the graft outcome between these groups at our centre. METHODS: The renal allograft function of 972 first cadaveric transplants performed between 1990 and 2001 in the Republic of Ireland was examined. The DGF and IGF were defined by a creatinine reduction ratio (CRR) between time 0 of transplantation and day 7 post-transplantation of <70 and >70%, respectively. Recipients with reduced graft function (DGF) not requiring dialysis were defined as slow graft function (SGF) patients. The serum creatinine at 3 months, 6 months, 1, 2 and 5 years after transplantation was compared between these groups of recipients. The graft survival rates at 1, 3 and 5 years and the graft half-life for DGF, SGF and IGF recipients were also assessed. RESULTS: Of the 972 renal transplant recipients, DGF was seen in 102 (10.5%) patients, SGF in 202 (20.8%) recipients and IGF in 668 (68.7%) patients. Serum creatinine levels were significantly different between the three groups at 3 and 6 months, 1, 2 and 5 years. Graft survival at 5 years for the DGF patients was 48.5%, 60.5% for SGF recipients and 75% for IGF patients with graft half-life of 4.9, 8.7 and 10.5 years, respectively. CONCLUSION: This study has shown that the CRR at day 7 correlates with renal function up to 5 years post-transplantation and with long-term graft survival. We have also demonstrated that amongst patients with reduced graft function after transplantation, two groups with significantly different outcomes exist.     

Impact of cold ischemia time on renal allograft outcome using kidneys from young donors

Prolonged cold ischemia time (CIT) is associated with delayed graft function and worse kidney transplant (KT) outcome, but the effect of CIT on long‐term allograft survival in KT from younger donors has not been well established. We investigated the predictive value of CIT exposure on long‐term death‐censored graft loss in 829 KT recipients from younger donors (<50 years) that were performed in our center between 1991 and 2005. Overall death‐censored graft failure rate was significantly higher in CIT≥19 h group versus CIT<19 h group (26 vs. 16.5%; P = 0.002). Significant differences were also observed when patients with primary nonfunctioning graft were excluded (21 vs. 14%; P = 0.020) and in patients who received tacrolimus plus mycophenolate mofetil (12 vs. 4%; P = 0.05). By multivariate Cox analysis, CIT was found to be independently associated with death‐censored graft loss with a 20% increase for every 5 h of CIT [relative risk (RR) 1.04; 95% Confidence Interval (CI): 1.01–1.1; P = 0.021]. Likewise, graft loss risk significantly increased in CIT≥19 h group versus CIT<19 h group (RR 1.5; 95%CI: 1.1–2.1; P = 0.023). Prolonged CIT is an independent predictor of graft survival in KT from younger donors. Efforts at minimizing CIT (<19 h) should improve transplant outcome significantly in this population.     

Comparison of early renal function parameters for the prediction of 5-year graft survival after kidney transplantation.

BACKGROUND: Early graft function (EGF) has an enduring effect on the subsequent course after kidney transplantation. This study compares quantitative parameters of EGF for the prediction of graft survival. METHODS: We involved 300 consecutive transplant recipients from deceased donors from 1989 to 2005. Urine output during 24 h post-transplant (UO), and serum creatinine after 1 week (Cr7) were taken for explanatory variables. We generated Kaplan-Meier (K-M) estimates of graft survival, by quintiles of the explanatory variable. Cox regression was applied to control for various recipient factors. RESULTS: K-M survival estimates indicate a threshold effect of UO and Cr7, which can dissect the risk of graft failure. The thresholds referring to the 2nd quintile correspond to a UO >630 ml and a Cr7 <2.5 mg/dl and were associated with a proportional hazard ratio of 0.52 (95% CI 0.33-0.84) and 0.34 (95% CI 0.18-0.65), respectively. Combining both of the parameters predicted a 5-year graft survival probability >90%, according to a hazard ratio of 0.21 (95% CI 0.09-0.46). Requirement of dialysis post-transplant lost its discriminatory power and was not a significant explanatory variable in the multivariate analysis. CONCLUSION: Routine parameters for monitoring of EGF display a threshold effect allowing accurate prediction of 5-year graft survival at the earliest point in time. The quantitative threshold levels for an optimum discriminatory power require validation in a larger, preferably multicentre database.     

Kidney donation after circulatory death in a country with a high number of brain dead donors: 10-year experience in Belgium

Worldwide shortage of standard brain dead donors (DBD) has revived the use of kidneys donated after circulatory death (DCD). We reviewed the Belgian DCD kidney transplant (KT) experience since its reintroduction in 2000. Risk factors for delayed graft function (DGF) were identified using multivariate analysis. Five-year patient/graft survival was assessed using Kaplan-Meier curves. The evolution of the kidney donor type and the impact of DCDs on the total KT activity in Belgium were compared with the Netherlands. Between 2000 and 2009, 287 DCD KT were performed. Primary nonfunction occurred in 1% and DGF in 31%. Five-year patient and death-censored graft survival were 93% and 95%, respectively. In multivariate analysis, cold storage (versus machine perfusion), cold ischemic time, and histidine-tryptophan-ketoglutarate solution were independent risk factors for the development of DGF. Despite an increased number of DCD donations and transplantations, the total number of deceased KT did not increase significantly. This could suggest a shift from DBDs to DCDs. To increase KT activity, Belgium should further expand controlled DCD programs while simultaneously improve the identification of all potential DBDs and avoid their referral for donation as DCDs before brain death occurs. Furthermore, living donation remains underused.     

A report on the activity and clinical outcomes of renal non-heart beating donor transplantation in the United Kingdom

The use of kidneys from non-heart beating donors (NHBDs) presents a paradox; whilst they provide more organs for transplantation, there is an increased risk of poor graft outcome, particularly in the short term. This study has highlighted the difference in early graft function and late graft survival between NHBD kidneys with short (controlled) and long (uncontrolled) warm ischaemic times. Whilst it would seem that it is preferable to use controlled donors only, their numbers are small. By employing a rational approach to the use of each of these types of kidney, such as structured viability assessment and risk analysis, it may be that the results of uncontrolled NHBD can be improved.