Living donor age and kidney allograft half-life: implications for living donor paired exchange programs

Elderly kidney transplant recipients have favorable outcomes but increased infection-related mortality

Background

The number of elderly patients with end-stage kidney disease has been increasing, but the outcomes of kidney transplants (KT) remain poorly understood in elderly patients. Therefore, we evaluated the clinical outcomes of elderly KT recipients and analyzed the impact of elderly donors.

Methods

This retrospective cohort study included patients who underwent KT between 2000 and 2019. KT recipients were divided into four groups according to a combination of recipient and donor age (≥60 or <60 years); elderly recipients: old-to-old (n = 46) and young-to-old (n = 83); young recipients: old-to-young (n = 98) and young-to-young (n = 796). We compared the risks of mortality, graft failure, and acute rejection between groups using Cox regression analysis.

Results

The incidence of delayed graft function, graft failure, and acute rejection was not different among groups. Annual mean tacrolimus trough level was not lower in elderly recipients than young recipients during 10-year follow-up. Mortality was significantly higher in elderly recipients (p = 0.001), particularly infection-related mortality (p < 0.001). In multivariable Cox regression analysis, old-to-old and young-to-old groups had increased risk of mortality (adjusted hazard ratio [aHR], 2.89; 95% confidence interval [CI], 1.14–7.32; p = 0.03; aHR, 3.06; 95% CI, 1.51–6.20; p = 0.002). However, graft failure and acute rejection risks were not increased in elderly recipients.

Conclusion

In elderly recipients, graft survival and acute rejection-free survival were not inferior to those of young recipients. However, mortality, especially risk of infection-related death, was increased in elderly recipients. Thus, low immunosuppression intensity might help decrease mortality in elderly recipients.

Impact of the Type of Dialysis on Time to Transplantation: Is It Just a Matter of Immunity?

Background: Renal transplantation represents the therapeutic gold standard in patients with end stage renal disease (ESRD). Still the role of pre-transplant dialysis in affecting time to transplantation has yet to be determined. We wanted to verify whether the type of renal replacement therapy (hemodialysis vs. peritoneal dialysis) affects time to transplantation and to identify clinical features related to the longer time to transplantation. Methods: We performed a retrospective single-center observational study on patients who had received a transplant in the Bologna Transplant Unit from 1991 to 2019, described through the analysis of digital transplant list documents for sex, age, body mass index (BMI), blood group, comorbidities, underlying disease, serology, type of dialysis, time to transplantation, Panel Reactive Antibodies (PRA) max, number of preformed anti Human Leukocyte Antigens (HLA) antibodies. A p-value < 0.05 was considered statistically significant. Results: In the 1619 patients analyzed, we observed a significant difference in time to transplant, PRA max and Preformed Antibodies Number between patients who received Hemodialysis (HD) and Peritoneal dialysis (PD). Then we performed a multiple regression analysis with all the considered factors in order to identify features that support these differences. The clinical variables that independently and directly correlate with longer time to transplantation are PRA max (p < 0.0001), Antibodies number (p < 0.0001) and HD (p < 0.0001); though AB blood group (p < 0.0001), age (p < 0.003) and PD (p < 0.0001) inversely correlate with time to transplantation. Conclusions: In our work, PD population received renal transplants in a shorter period of time compared to HD and turned out to be less immunized. Considering immunization, the type of dialysis impacts both on PRA max and on anti HLA antibodies.

A Historical Cohort in Kidney Transplantation: 55-Year Follow-Up of 72 HLA-Identical, Donor-Recipient Pairs

The impact of HLA matching on graft survival has been well characterized in renal transplantation, with a higher degree of matching associated with superior graft survival. Additionally, living donor grafts are known to confer superior survival compared to those from deceased donors. The purpose of this study is to report our multi-decade institutional experience and outcomes for patients who received HLA-identical living donor grafts, which represent the most favorable scenario in kidney transplantation. We conducted a retrospective analysis of these graft recipients performed at a Duke University Medical Center between the years of 1965 and 2002. The recipients demonstrated excellent graft and patient survival outcomes, superior to a contemporary cohort, with median patient and graft survival of 24.2 and 30.9 years, respectively, among Duke recipients vs. 16.1 and 16.0 years in a cohort derived from national data. This study offers a broad perspective on the importance of HLA matching and graft type, and demonstrates a historical best-case-scenario in renal transplantation.

Long-Term Results of Kidney Transplantation in the Elderly: Comparison between Different Donor Settings

With scarce organ supply, a selection of suitable elderly candidates for transplant is needed, as well as auditing the long-term outcomes after transplant. We conducted an observational cohort study among our patient cohort >60 years old with a long follow up. (1). Patients and Methods: We used our database to study the results after transplant for 593 patients >60 years old who underwent a transplant between 2000–2017. The outcome was compared between live donor (LD; n = 257) recipients, an old-to-old (OTO, n = 215) group using an extended criteria donor (ECD) kidney, and a young-to-old (YTO, n = 123) group using a standard-criteria donor. The Kaplan−Meir method was used to calculate the patient and graft survival and Cox regression analysis in order to find risk factors associated with death. (2). Results: The 5- and 10-year patient survival was significantly better in the LD group (92.7% and 66.9%) compared with the OTO group (73.3% and 42.8%) and YTO group (70.9% and 40.6%) (p < 0.0001). The 5- and 10-year graft survival rates were 90.3% and 68.5% (LD), 61.7% and 30.9% (OTO), and 64.1% and 39.9%, respectively (YTO group; p < 0.0001 between the LD and the two DD groups). There was no difference in outcome between patients in their 60’s and their 70’s. Factors associated with mortality included: age (HR-1.060), DM (HR-1.773), IHD (HR-1.510), and LD/DD (HR-2.865). (3). Conclusions: Our 17-years of experience seems to justify the rational of an old-to-old allocation policy in the elderly population. Live-donor transplant should be encouraged whenever possible. Each individual decision of elderly candidates for transplant should be based on the patient’s comorbidity and predicted life expectancy.

Disparity in the access to kidney transplantation for sensitized patients in the state of Sao Paulo-Brazil

Highly sensitized (HS) patients accumulate on deceased donor kidney transplantation (DDKT) waitlists worldwide due to matching difficulty and inequity of allocation policies. Current situation of HS patients on KT waitlist in Brazil has not been published. All patients enrolled on the KT waitlist of the State of São Paulo from 2002 to 2017 were retrospectively assessed. Patients were divided into eight groups according to their degree of sensitization, PRA of 0%, >0-40%, >40-80%, >80-85%, >85-90%, >90-95%, >95-98% and > 98%. Cumulative incidence curves for transplantation or mortality/removal from waitlist were estimated by competing risk. Among 50,249 waitlisted candidates, 1247 prioritized, 2467 with age < 18 or > 75 years and 4152 submitted to living-donor KT were excluded from the analysis, remaining 42,383 patients. There were 29,664(70%) PRA 0%, 5611(13.2%) PRA > 0-40%, 3442(8.2%) PRA > 40-80%, 507(1.2%) PRA > 80-85%, 564(1.3%) PRA > 85-90%, 825(1.9%) PRA >90-95%, 859(2%) PRA > 95-98% and 911(2.2%) PRA > 98%. There was a progressive increase in the need of prioritization, waiting time for KT or on waitlist and time on dialysis as PRA increased (p < 0.001). Probability of DDKT clearly increased as PRA decreased so that PRA 0% candidates were much more likely to be transplanted compared to PRA > 98% patients(HR:13.02, p < 0.001). Waiting list mortality/removal was higher among PRA > 0-40%(HR1.05,p = 0.03), PRA > 90-95%(HR:1.10,p = 0.05), PRA > 95-98%(HR:1.26,p < 0.001) and PRA > 98%(HR:1.09,p = 0.05) patients compared to PRA zero candidates. HS patients in Sao Paulo-Brazil required greater prioritization due to lack of venous access, longer dialysis and waitlist times, lower probability of DDKT and higher rates of waitlist mortality/removal. We confirmed the disparity of access to KT among HS patients in Sao Paulo-Brazil, indicating the need of new strategies that optimize transplantation for this subcategory of patients.

Thiol-ene cross-linked alginate hydrogel encapsulation modulates the extracellular matrix of kidney organoids by reducing abnormal type 1a1 collagen deposition

Differentiated kidney organoids from induced pluripotent stem cells hold promise as a treatment for patients with kidney diseases. Before these organoids can be translated to the clinic, shortcomings regarding their cellular and extracellular compositions, and their developmental plateau need to be overcome. We performed a proteomic analysis on kidney organoids cultured for a prolonged culture time and we found a specific change in the extracellular matrix composition with increased expression of types 1a1, 2 and 6a1 collagen. Such an excessive accumulation of specific collagen types is a hallmark of renal fibrosis that causes a life-threatening pathological condition by compromising key functions of the human kidney. Here we hypothesized the need for a three-dimensional environment to grow the kidney organoids, which could better mimic the in vivo surroundings of the developing kidney than standard culture on an air-liquid interface. Encapsulating organoids for four days in a soft, thiol-ene cross-linked alginate hydrogel resulted in decreased type 1a1 collagen expression. Furthermore, the encapsulation did not result in any changes of organoid structural morphology. Using a biomaterial to modulate collagen expression allows for a prolonged kidney organoid culture in vitro and a reduction of abnormal type 1a1 collagen expression bringing kidney organoids closer to clinical application.

The differential impact of size mismatch in live versus deceased donor kidney transplant

BACKGROUND

The impact of weight mismatch between donors and recipients (D-R) undergoing living-donor kidney transplant (LDKT) versus weight-matched deceased donor kidney transplant (DDKT) is not established.

AIM

To determine whether absolute weight mismatch between D-R affects graft survival following LDKT and how this relates to graft outcomes with DDKT when D-R are weight matched.

MATERIALS & METHODS

We used multivariable Cox proportional hazards models and the Scientific Registry of Transplant Recipients to determine the association of weight-mismatched D-R (>50 kg, 30-50 kg or 10-30 kg ((D < R); (D > R) and <10 kg (D = R)) with death-censored graft failure in US LDKT recipients from 2006 to 2017. We also explored outcomes relative to weight-matched DDKT and finally, the impact of combined D-R weight-sex mismatch.

RESULTS

In LDKT, the risk of graft loss was highest in the setting of D < R (HR 1.28, 95% CI 1.05-1.56 for >50 kg difference relative to D = R); however, this was still lower risk than weight-matched DDKT. D-R sex and combined weight-sex mismatch were only important for male recipients (HR 1.47, 95% CI 1.27-1.71 for a male recipient >30 kg larger than their female donor, relative to weight-matched male donor-male recipient). This remained superior to weight-sex-matched DDKT however.

CONCLUSION

D-R weight-sex mismatch is important in LDKT; however, graft survival remains superior to proceeding with matched DDKT. Optimizing D-R matching in LDKT could be facilitated through a national kidney-paired donation registry. LDKT weight-sex mismatch should not be deferred in favor of DDKT.

A review of imlifidase in solid organ transplantation

INTRODUCTION

Sensitization to human leukocyte antigens has long posed an obstacle to organ transplantation. With desensitization protocol refinement, new drug development, and organ allocation policy changes, access to transplant for sensitized patients has never been greater. Yet in spite of these advances the problem of donor-specific antibody remains incompletely solved, and many patients remain poorly served by the therapies that do exist. Area covered: Imlifidase is a new drug with a mechanism of action that enables it to transiently yet efficiently eliminate donor-specific antibody over a much more rapid time course than any heretofore existing therapy. This unique property suggests that imlifidase may have far-reaching potential for patients in whom donor-specific antibodies may preclude successful transplantation. Below follows a review of the clinical experience with imlifidase to date as well as a discussion of the transplant applications that eagerly await the availability of this novel agent. Expert opinion: Imlifidase is a first-in-class pharmaceutical agent that safely and efficiently cleaves IgG, and holds promise to be a game-changer for sensitized patients in need of lifesaving organ transplants.

How do highly sensitized patients get kidney transplants in the United States? Trends over the last decade

Prioritization of highly sensitized (HS) candidates under the kidney allocation system (KAS) and growth of large, multicenter kidney-paired donation (KPD) clearinghouses have broadened the transplant modalities available to HS candidates. To quantify temporal trends in utilization of these modalities, we used SRTR data from 2009 to 2017 to study 39 907 adult HS (cPRA ≥ 80%) waitlisted candidates and 19 003 recipients. We used competing risks regression to quantify temporal trends in likelihood of DDKT, KPD, and non-KPD LDKT for HS candidates (Era 1: January 1, 2009-December 31, 2011; Era 2: January 1, 2012-December 3, 2014; Era 3: December 4, 2014-December 31, 2017). Although the likelihood of DDKT and KPD increased over time for all HS candidates (adjusted subhazard ratio [aSHR] Era 3 vs 1 for DDKT: 1.74 1.851.97 , P < .001 and for KPD: 1.70 2.202.84 , P < .001), the likelihood of non-KPD LDKT decreased (aSHR: 0.69 0.820.97 , P = .02). However, these changes affected HS recipients differently based on cPRA. Among recipients, more cPRA 98%-99.9% and 99.9%+ recipients underwent DDKT (96.2% in Era 3% vs 59.1% in Era 1 for cPRA 99.9%+), whereas fewer underwent non-KPD LDKT (1.9% vs 30.9%) or KPD (2.0% vs 10.0%). Although KAS increased DDKT likelihood for the most HS candidates, it also decreased the use of non-KPD LDKT to transplant cPRA 98%+ candidates.

Pediatric deceased donor kidney transplant outcomes under the Kidney Allocation System

The Kidney Allocation System (KAS) has resulted in fewer pediatric kidneys being allocated to pediatric deceased donor kidney transplant (pDDKT) recipients. This had prompted concerns that post-pDDKT outcomes may worsen. To study this, we used SRTR data to compare the outcomes of 953 pre-KAS pDDKT (age <18 years) recipients (December 4, 2012-December 3, 2014) with the outcomes of 934 post-KAS pDDKT recipients (December 4, 2014-December 3, 2016). We analyzed mortality and graft loss by using Cox regression, delayed graft function (DGF) by using logistic regression, and length of stay (LOS) by using negative binomial regression. Post-KAS recipients had longer pretransplant dialysis times (median 1.26 vs 1.07 years, P = .02) and were more often cPRA 100% (2.0% vs 0.1%, P = .001). Post-KAS recipients had less graft loss than pre-KAS recipients (hazard ratio [HR]: _0.35 0.54_0.83 , P = .005) but no statistically significant differences in mortality (HR: _0.29 0.72_1.83 , P = .5), DGF (odds ratio: _0.93 1.32_1.93 , P = .2), and LOS (LOS ratio: _0.96 1.06_1.19 , P = .4). After adjusting for donor-recipient characteristics, there were no statistically significant post-KAS differences in mortality (adjusted HR: _0.37 1.04_2.92 , P = .9), DGF (adjusted odds ratio: _0.94 1.41_2.13 , P = .1), or LOS (adjusted LOS ratio: _0.93 1.04_1.16 , P = .5). However, post-KAS pDDKT recipients still had less graft loss (adjusted HR: _0.38 0.59_0.91 , P = .02). KAS has had a mixed effect on short-term posttransplant outcomes for pDDKT recipients, although our results are limited by only 2 years of posttransplant follow-up.

Survival analysis of patients in the waiting list for kidney transplantation in terms of competing risks

Aim: to analyze the survival of patients on the waiting list for kidney transplantation and the results of transplantation depending on the duration of waiting.

Materials and methods. We performed a retrospective observational analysis that included 1,197 patients on the waiting list. The end point was exclusion from the waiting list (WL). The causes for exclusion (death, exclusion due to deterioration of the comorbid background or transplantation) were considered in terms of competing risks.

Results. In total, 72.5% of patients reached the end point: 21.1% of them died, 11% were excluded, and 40.4% underwent transplantation. Kaplan–Meier estimate showed that cumulative risk of death was 80.4% [95% CI 77.9; 88.6], of exclusion was 77.9% [95% CI 65.4; 88.2], of transplantation was 63.6% [95% CI 58.3; 69] after 10 years on the waiting list. However, such an assessment cannot be directly interpreted as a prediction of the relevant event risk of occurrence for the patient in the WL, because it does not take into account competing events. According to a balanced assessment of the competing risks (Fine and Gray estimate), cumulative incidence was 30.9% (95% CI 27.7; 34.2) for death, 18.2% [95% CI 15.5; 21.1] for exclusion and 49.4% [95% CI 46; 52.6%] for transplantation after 10 years on WL. The probability of transplantation was significantly higher than the risk of death up to and including 5 years of waiting (incidence rate ratio – IRR 1.769 [95% CI 1.098; 2.897]). When waiting 7 to 8 years, the probability of transplantation was less than the risk of death: IRR 0.25 (95% CI 0.093; 0.588; p = 0.0009). Of the 483 recipients, 61 died and 119 returned to dialysis. The risk of graft loss after 10 years was 68.5% [95% CI 57.5; 79.1] and the risk of death of a recipient with a functioning graft was 48.3% [95% CI 34.7; 63] according to Kaplan–Meier estimate. The cumulative incidence of the method was 30.8% [95% CI 23.3; 38.5%] and 55.7% [95% CI 46.6; 63.5%] according to Fine and Gray estimate, respectively. The risk of death after transplantation increases significantly when waiting for more than 6 years – IRR 4.325 [95% CI 1.649; 10.47], p = 0.0045 relative to a shorter waiting period. With an increase in the waiting period, the comorbid background (CIRS scale) deteriorates significantly, even adjusted for the initial patient condition: the partial correlation r = 0.735; p < 0.0001.

Conclusion. 1. In the context of competing risks, the Fine and Gray estimate gives a more balanced risk assessment compared to the Kaplan–Meier method. 2. Increasing the waiting time for transplantation significantly increases the risk of death of the candidate on the waiting list and reduces the probability of transplantation, as well as increases the risk of death of the recipient after transplantation. Apparently, this is mainly due to the deterioration of the comorbid background.

The national landscape of deceased donor kidney transplantation for the highly sensitized: Transplant rates, waitlist mortality, and posttransplant survival under KAS

Deceased donor kidney transplantation (DDKT) rates for highly sensitized (HS) candidates increased early after implementation of the Kidney Allocation System (KAS) in 2014. However, this may represent a bolus effect, and a granular investigation of the current state of DDKT for HS candidates remains lacking. We studied 270 722 DDKT candidates from the SRTR from 12/4/2011 to 12/3/2014 ("pre-KAS") and 12/4/2014 to 12/3/2017 ("post-KAS"), analyzing DDKT rates for HS candidates using adjusted negative binomial regression. Post-KAS, candidates with the highest levels of sensitization had an increased DDKT rate compared with pre-KAS (cPRA 98% adjusted incidence rate ratio [aIRR]:1.27 1.772.46 P = .001, cPRA 99% aIRR:3.18 4.365.98 P < .001, cPRA 99.5-99.9% aIRR:16.91 24.2934.89 P < .001, and cPRA 99.9%+ aIRR:8.79 11.5815.26 P < .001). To determine whether these changes produced more equitable access to DDKT, we compared DDKT rates of HS to non-HS candidates (cPRA 0-79%). Post-KAS, cPRA, 98% candidates had an equivalent DDKT rate (aIRR:0.65 0.941.36 , P = .8) to non-HS candidates, whereas 99% candidates had a higher DDKT rate (aIRR:1.19 1.682.38 , P = .02). Although cPRA 99.5-99.9% candidates had an increased DDKT rate (aIRR:2.46 3.504.98 , P < .001) compared to non-HS candidates, cPRA 99.9%+ candidates had a significantly lower DDKT rate (aIRR:0.29 0.400.56 , P < .001). KAS has improved access to DDKT for HS candidates, although substantial imbalance exists between cPRA 99.5-99.9% and 99.9%+ candidates.

The 6-year clinical outcomes for patients registered in a multiregional United States Kidney Paired Donation program - a retrospective study

We examined what happened during a 6-year period to 1121 end-stage renal disease patients who registered with their willing/incompatible living donors for kidney exchanges with the Alliance for Paired Donation (APD). Of all patients, 65% were transplanted: 37% in kidney paired donation (APD-KPD, APD-other-KPD); 10% with compatible live donors (APD-LD); and 18% with deceased donors (APD-DD). The remaining patients were withdrawn (sick/died/others; 15%), or were still waiting (20%). For those patients with a cPRA 0-94%, 72% received a transplant. In contrast, only 49% of very highly sensitized (VHS; cPRA 95-100%) were transplanted. Of the VHS patients, 50% were transplanted by KPD/APD-LD while 50% benefited through prioritization of deceased donors in the modified kidney allocation system (KAS introduced in 2014). All APD transplanted groups had similar death-censored 4-year graft survivals as their relevant Organ Procurement and Transplantation Network (OPTN) groups. It is noteworthy that VHS graft and patient survival results were comparable to less sensitized and nonsensitized patients. All patients should be encouraged to search for compatible donors through different options. Expanding the donor pool through KPD and the new KAS of the OPTN increases the likelihood of transplantation for VHS patients.

Lifetime risk of end-stage kidney disease in living donors for paediatric kidney transplant recipients in Australia and New Zealand - a retrospective study

Living kidney donors (LKD) for paediatric kidney transplant recipients (KTR) have a heightened motivation to donate for emotional reasons and the clear health benefits to the KTR. We hypothesized that the cohort of LKD for paediatric KTR (LKD-P) includes motivated young parents with a higher lifetime end-stage kidney disease (ESKD) risk compared to adult KTR (LKD-A). Data from the Australia and New Zealand Dialysis and Transplant LKD Registry (2004-2015) was analysed to compare baseline characteristics and predonation ESKD risk in LKD-P (n = 315) versus LKD-A (n = 3448). LKD-P were younger (median age 42 vs. 50 years; P < 0.001) and had a marginally higher lifetime ESKD risk (median 0.44% vs. 0.40%; P < 0.01), with a similar proportion of LKD exceeding 1% risk threshold (5.4% vs. 5.6%; P = NS). Compared to grandparents as LKD-P, parents (median age 41 vs. 59 years; P < 0.001) had a higher lifetime ESKD (0.44% vs. 0.25%; P < 0.001). Although unique benefits to paediatric KTR justify the minor increase in lifetime ESKD risk in young parents, carefully selected grandparents are an alternative LKD-P option, allowing parents to donate for subsequent transplants.

[Focusing on kidney transplantation in the elderly]

Due to the increase in life expectancy and the ageing of end-stage renal disease patients, the number of patients older than 65 years receiving a kidney transplant has been continuously growing over the last fifteen years. The benefits of renal transplantation compared to dialysis in terms of survival and quality of life have been shown in selected recipients over 65, or 70 years. However, the age remains the main limiting factor for the access to the waiting list, and the reluctance of the clinicians can be explained by the multiple comorbidities of these candidates, their limited life expectancy or the shortage of grafts. The challenge is to select the candidates who can benefit from renal transplantation, thanks to rigorous cardiovascular and neoplastic evaluation before enrolment and by taking into account the specific characteristics of elderly patients. The living donor appears to be the ideal option for elderly recipients, the alternative being the extended criteria donor, allowing waiting times to be limited. The choice of immunosuppressive therapy is also crucial in these patients at high risk of infectious and cardiovascular complications in whom the occurrence of acute rejection can have severe consequences. There are currently no specific recommendations for immunosuppression in elderly recipients, and we would need large-scale randomized studies to improve the prognosis of renal transplantation in this population.

Chronic kidney disease

Chronic kidney disease (CKD) is defined by persistent urine abnormalities, structural abnormalities or impaired excretory renal function suggestive of a loss of functional nephrons. The majority of patients with CKD are at risk of accelerated cardiovascular disease and death. For those who progress to end-stage renal disease, the limited accessibility to renal replacement therapy is a problem in many parts of the world. Risk factors for the development and progression of CKD include low nephron number at birth, nephron loss due to increasing age and acute or chronic kidney injuries caused by toxic exposures or diseases (for example, obesity and type 2 diabetes mellitus). The management of patients with CKD is focused on early detection or prevention, treatment of the underlying cause (if possible) to curb progression and attention to secondary processes that contribute to ongoing nephron loss. Blood pressure control, inhibition of the renin-angiotensin system and disease-specific interventions are the cornerstones of therapy. CKD complications such as anaemia, metabolic acidosis and secondary hyperparathyroidism affect cardiovascular health and quality of life, and require diagnosis and treatment.

Multiplex Partial Nephrectomy, Repeat Partial Nephrectomy, and Salvage Partial Nephrectomy Remain the Primary Treatment in Multifocal and Hereditary Kidney Cancer

The standard of care treatment for solitary renal cell carcinoma (RCC) tumors 4 cm or less is partial nephrectomy (PNx). However, multifocal kidney cancer presents unique challenges for treating physicians. Historically, total nephrectomy and hemodialysis with possible renal transplant later was the primary therapeutic strategy for these patients. Later, as nephron sparing surgical approaches improved, PNx became the standard of care for patients presenting with multifocal and hereditary RCC. Surgeries to remove multiple renal tumors simultaneously produce different perioperative outcomes and increased risk of complications. Due to these differences in technique and outcomes, the term multiplex partial nephrectomy (MxPNx) has been coined to designate these differences. Here, we discuss the role that MxPNx continues to play in multifocal RCC.

Reciprocity to Increase Participation of Compatible Living Donor and Recipient Pairs in Kidney Paired Donation

Inclusion of compatible living donor and recipient pairs (CPs) in kidney paired donation (KPD) programs could increase living donor transplantation. We introduce the concept of a reciprocity-based strategy in which the recipient of a CP who participates in KPD receives priority for a repeat deceased donor transplant in the event their primary living donor KPD transplant fails, and then we review the practical and ethical considerations of this strategy. The strategy limits prioritization to CPs already committed to living donation, minimizing the risk of unduly influencing donor behavior. The provision of a tangible benefit independent of the CP's actual KPD match avoids many of the practical and ethical challenges with strategies that rely on finding the CP recipient a better-matched kidney that might provide the CP recipient a future benefit to increase KPD participation. Specifically, the strategy avoids the potential to misrepresent the degree of future benefit of a better-matched kidney to the CP recipient and minimizes delays in transplantation related to finding a better-matched kidney. Preliminary estimates suggest the strategy has significant potential to increase the number of living donor transplants. Further evaluation of the acceptance of this strategy by CPs and by waitlisted patients is warranted.

Cold ischemia time up to 16 hours has little impact on living donor kidney transplant outcomes in the era of kidney paired donation

In living donor transplantation, cold ischemia time is a concern in transplants involving kidney paired donation. The impact of cold ischemia time over eight hours is unknown. Here we examined the association of cold ischemia time with delayed graft function and allograft loss among 48,498 living recipients in the Scientific Registry of Transplant Recipients registry. The incidence of delayed graft function was low but significantly higher among patients with longer cold ischemia times (0-2.0 hours: 3.3%; 2.1-4.0 hours: 3.9%; 4.1-8.0 hours: 4.3%; 8.1-16.0 hours: 5.5%). In multivariate analyses, only those with cold ischemia times of 8.1-16.0 hours had increased odds of delayed graft function (odds ratio 1.47; 95% confidence interval 1.05-2.05) compared to patients with times of 0-2.0 hours. In multivariate time-to-event analyses, cold ischemia times of 16 hours or less were not associated with allograft loss from any cause including death or death-censored graft loss with hazard ratios for cold ischemia times between 8.0-16.0 hours of 0.97 (95% confidence interval 0.74-1.26) and 1.09 (0.81-1.48) compared to patients with times of 0-2.0 hours). The results were consistent in paired and non-kidney paired donation transplants and in those with living donors over 50 years of age. In subgroup analysis restricted to kidney paired donation recipients, there was no difference in the risk of delayed graft function with an odds ratio of 1.40 (0.88, 2.40) or all-cause graft loss with a hazard ratio of 0.89 (0.62, 1.30) in transplant recipients who received kidneys that were shipped versus not shipped. Thus, a cold ischemia time up to 16 hours has limited impact on living donor outcomes. These findings may help expand living donor transplantation through kidney paired donation.

Acceptability of older adults as living kidney donors

PURPOSE OF REVIEW

Kidney transplantation from a living kidney donor (LKD) is associated with better long-term survival and quality of life for a patient with end-stage renal disease (ESRD) than dialysis. We reviewed recent literature on the acceptability and outcomes of older adults as LKDs, which may be misunderstood in routine care.

RECENT FINDINGS

Studies report that receiving a kidney from an older LKD is associated with worse recipient and graft survival compared with receiving a kidney from a younger LKD, but similar recipient and graft survival to receiving a kidney from a standard criteria deceased donor. A kidney from a younger vs. older LKD results in better graft survival in younger recipients, whereas the graft survival is similar in older recipients. Compared with healthy matched nondonors, older LKDs have a similar risk of death and cardiovascular disease and the absolute risk of ESRD after 15 years remains less than 1%. The estimated predonation and postdonation lifetime risk of ESRD varies by age, sex and race with lower incidences in individuals who are older, female and white (vs. African-American).

SUMMARY

Donor and recipient outcomes from several studies support the acceptability of older adults as LKDs.

Changing Paradigms in the Management of Rejection in Kidney Transplantation: Evolving From Protocol-Based Care to the Era of P4 Medicine

PURPOSE OF REVIEW

P4 medicine denotes an evolving field of medicine encompassing predictive, preventive, personalized, and participatory medicine. Using the example of kidney allograft rejection because of donor-recipient incompatibility in human leukocyte antigens, this review outlines P4 medicine's relevance to the various stages of the kidney transplant cycle.

SOURCES OF INFORMATION

A search for English articles was conducted in Medline via OvidSP (up to August 18, 2016) using a combination of subject headings (MeSH) and free text in titles, abstracts, and author keywords for the concepts kidney transplantation and P4 medicine. The electronic database search was expanded further on particular subject headings.

FINDINGS

Available histocompatibility methods exemplify current applications of the predictive and preventive domains of P4 medicine in kidney transplant recipients' care. Pharmacogenomics are discussed as means to facilitate personalized immunosuppression regimens and promotion of active patient participation as a means to improve adherence.

LIMITATIONS

For simplicity, this review focuses on rejection. P4 medicine, however, should more broadly address health concerns in kidney transplant recipients, including competing outcomes such as infections, malignancies, and cardiovascular disease. This review highlights how biomarkers to evaluate these competing outcomes warrant validation and standardization prior to their incorporation into clinical practice.

IMPLICATIONS

Consideration of all 4 domains of the P4 medicine framework when caring for and/or studying kidney transplant recipients has the potential of increasing therapeutic efficiency, minimizing adverse effects, decreasing health care costs, and maximizing wellness. Technologies to gauge immune competency, immunosuppression requirements, and early/reversible immune-mediated injuries are required to optimize kidney transplant care.

Calculated panel reactive antibody with decimals: A refined metric of access to transplantation for highly sensitized candidates

The use of the calculated panel reactive antibody (CPRA) value and the implementation of allocation points for sensitized candidates by the United Network for Organ Sharing (UNOS) have improved access to kidney transplantation for highly sensitized candidates (98% CPRA and above). Despite this, a large population of highly sensitized candidates remain awaiting transplantation. To better define this population, we propose the use of two refinements of the standard UNOS CPRA, the CPRA with decimals or CPRAd, and the likelihood of a compatible donor (LCD). These refined metrics of the standard UNOS CPRA will allow transplant programs to describe their patients' access to transplantation with increased granularity and will help in decisions regarding the use of desensitization.

The Long-Term Follow-up and Support for Living Organ Donors: A Center-Based Initiative Founded on Developing a Community of Living Donors

Transplant professionals recognize that the long-term follow-up of living organ donors is a priority, yet there has been no implemented solution to this problem. This critical gap is essential, because the transplant field is now emphasizing living donation as a means to address the organ shortage. We detail our living donor initiative, which sets several priorities we recognize as fundamental to persons who have donated organs at our transplant center. This intervention attempts to mitigate the donor and center factors that are known to contribute to the lack of long-term follow-up. Beyond that, our goals are aimed at providing ongoing engagement, wellness, clinical data accrual, laboratory follow-up, and social support for our living donors, in continuity. Our ultimate goal is to nurture the development of local living donor community networks by providing social engagement for current and past donors, which also serves as a platform for greater population education on the societal importance of living donation. This initiative is based on joint recognition by our transplant team and our hospital leadership that supporting the long-term welfare of living donors is essential to accomplishing the goal of expanding living donor transplantation. The transplant team and hospital missions are aligned, and both contribute resources to the initiative.

HLA Matching Trumps Donor Age: Donor-Recipient Pairing Characteristics That Impact Long-Term Success in Living Donor Kidney Transplantation in the Era of Paired Kidney Exchange

BACKGROUND

We sought to identify donor characteristics influencing long-term graft survival, expressed by a novel measure, kidney life years (KLYs), in living donor kidney transplantation (LDKT).

METHODS

Cox and multiple regression analyses were applied to data from the Scientific Registry for Transplant Research from 1987 to 2015. Dependent variable was KLYs.

RESULTS

Living donor kidney transplantation (129 273) were performed from 1987 to 2013 in the United States. To allow sufficient time to assess long-term results, outcomes of LDKTs between 1987 and 2001 were analyzed. After excluding cases where a patient died with a functioning graft (8301) or those missing HLA data (9), 40 371 cases were analyzed. Of 18 independent variables, the focus became the 4 variables that were the most statistically and clinically significant in that they are potentially modifiable in donor selection (P <0.0001; ie, HLA match points, donor sex, donor biological sibling and donor age). HLA match points had the strongest relationship with KLYs, was associated with the greatest tendency toward graft longevity on Cox regression, and had the largest increase in KLYs (2.0 year increase per 50 antigen Match Points) based on multiple regression.

CONCLUSIONS

In cases when a patient has multiple potential donors, such as through paired exchange, graft life might be extended when a donor with favorable matching characteristics is selected.

Four years of experience with the Australian kidney paired donation programme

New approaches to increase kidney transplantation rates through expansion of live donor kidney transplantation have become necessary due to ongoing shortage of deceased donor organs. These strategies include desensitization in antibody-incompatible transplants to overcome the barrier of blood group incompatibility or human leucocyte antigen antibodies between recipient and donor and kidney paired donation (KPD) programmes. In KPD, a kidney transplant candidate with an incompatible live donor joins a registry of other incompatible pairs in order to find potentially compatible transplant solutions. To match the largest possible number of donor-recipient pairs while minimizing immunologic risk, KPD programmes use sophisticated algorithms to identify suitable matches with simultaneous two-way or more complex multi-way exchanges as well as including non-directed anonymous donors to start a chain of compatible transplantations. Because of the significant immunologic barriers when fewer donor options are available, the optimal solution for difficult-to-match, highly sensitized patients is access to more potential donors using large multi-centre or national KPD registries. This review focuses on the first 4 years of experience with the Australian multi-centre KPD programme that was established in October 2010.

Transplanting the elderly: Balancing aging with histocompatibility

Across the world, the proportions of senior citizens (i.e. those ≥65years) increase rapidly and are predicted to constitute over 25% of the general population by 2050. In 2012 already 48% of the population with end stage renal disease (ESRD) was aged 65years or older. Transplantation is considered the preferred treatment option for ESRD offering survival advantage over long-term dialysis in the majority of patients. Indeed, acceptable outcomes have been documented for selected patients over the age of 70years or even cases over 80years. The reality of organ scarcity and prolonged waiting times for a deceased donor kidney transplantation, however, indicate that at best 50% of the selected elderly may have realistic expectations to receive a timely transplant offer. By choice or medical selection, access to transplantation also decreases with increasing age. In order to expedite the chance for elderly to receive a kidney transplant dedicated allocation systems have been developed. These allocation systems, like the Eurotransplant Senior Program (ESP), support preferential local allocation of kidneys from older donors to older patients in order to match recipient and graft life while disregarding histocompatibility for HLA antigens. The consequence has been more acute rejection episodes and an increase in immunosuppressive load. In the elderly, the most common cause of graft loss is death with functioning graft and death from infectious diseases is one of the dominant causes. The Eurotransplant Senior DR-compatible Program (ESDP) was designed to further improve the perspective of successful transplantation in the elderly in terms of life and quality of life by re-introducing matching criteria for HLA-DR in the old-for-old algorithm.

Kidney paired donation: principles, protocols and programs

Due to the ongoing shortage of deceased-donor organs, novel strategies to augment kidney transplantation rates through expanded living donation strategies have become essential. These include desensitization in antibody-incompatible transplants and kidney paired donation (KPD) programs. KPD enables kidney transplant candidates with willing but incompatible living donors to join a registry of other incompatible pairs in order to find potentially compatible transplant solutions. Given the significant immunologic barriers with fewer donor options, single-center or small KPD programs may be less successful in transplanting the more sensitized patients; the optimal solution for the difficult-to-match patient is access to more potential donors and large multicenter or national registries are essential. Multicenter KPD programs have become common in the last decade, and now represent one of the most promising opportunities to improve transplant rates. To maximize donor-recipient matching, and minimize immunologic risk, these multicenter KPD programs use sophisticated algorithms to identify optimal match potential, with simultaneous two-, three- or more complex multiway exchanges. The article focuses on the recent progresses in KPD and it also reviews some of the differences and commonalities across four different national KPD programs.

Outcomes in kidney transplant recipients from older living donors

BACKGROUND

Previous studies demonstrate that graft survival from older living kidney donors (LD; age>60 years) is worse than younger LD but similar to deceased standard criteria donors (SCD). Limited sample size has precluded more detailed analyses of transplants from older LD.

METHODS

Using the United Network for Organ Sharing database from 1994 to 2012, recipients were categorized by donor status: SCD, expanded criteria donor (ECD), or LD (by donor age: <60, 60-64, 65-69, ≥70 years). Adjusted models, controlling for donor and recipient risk factors, evaluated graft and recipient survivals.

RESULTS

Of 250,827 kidney transplants during the study period, 92,646 were LD kidneys, with 4.5% of these recipients (n=4,186) transplanted with older LD kidneys. The use of LD donors 60 years or older increased significantly from 3.6% in 1994 to 7.4% in 2011. Transplant recipients with older LD kidneys had significantly lower graft and overall survival compared to younger LD recipients. Compared to SCD recipients, graft survival was decreased in recipients with LD 70 years or older, but overall survival was similar. Older LD kidney recipients had better graft and overall survival than ECD recipients.

CONCLUSIONS

As use of older kidney donors increases, overall survival among kidney transplant recipients from older living donors was similar to or better than SCD recipients, better than ECD recipients, but worse than younger LD recipients. With increasing kidney donation from older adults to alleviate profound organ shortages, the use of older kidney donors appears to be an equivalent or beneficial alternative to awaiting deceased donor kidneys.

Increasing access to kidney transplantation in countries with limited resources: the Indian experience with kidney paired donation

According to the Indian chronic kidney disease registry, in 2010 only 2% of end stage kidney disease patients were managed with kidney transplantation, 37% were managed with dialysis and 61% were treated conservatively without renal replacement therapy. In countries like India, where a well-organized deceased donor kidney transplantation program is not available, living donor kidney transplantation is the major source of organs for kidney transplantation. The most common reason to decline a donor for directed living donation is ABO incompatibility, which eliminates up to one third of the potential living donor pool. Because access to transplantation with human leukocyte antigen (HLA)-desensitization protocols and ABO incompatible transplantation is very limited due to high costs and increased risk of infections from more intense immunosuppression, kidney paired donation (KPD) promises hope to a growing number of end stage kidney disease patients. KPD is a rapidly growing and cost-effective living donor kidney transplantation strategy for patients who are incompatible with their healthy, willing living donor. In principle, KPD is feasible for any centre that performs living donor kidney transplantation. In transplant centres with a large living donor kidney transplantation program KPD does not require extra infrastructure, decreases waiting time, avoids transplant tourism and prevents commercial trafficking. Although KPD is still underutilized in India, it has been performed more frequently in recent times. To substantially increase donor pool and transplant rates, transplant centres should work together towards a national KPD program and frame a uniform acceptable allocation policy.

Immune Sensitization and Mortality in Wait-Listed Kidney Transplant Candidates

Cardiovascular mortality is the leading cause of death in ESRD. Whereas innate and adaptive immunity have established roles in cardiovascular disease, the role of humoral immunity is unknown. We conducted a retrospective cohort study in first-time adult kidney transplant candidates (N=161,308) using data from the Scientific Registry of Transplant Recipients and the Centers for Medicare and Medicaid Services to evaluate whether anti-human leukocyte antigen antibodies, measured as panel reactive antibodies (PRAs), are related to mortality in ESRD. Relationships between time-varying PRAs and all-cause or cardiovascular mortality were assessed using Cox proportional hazards models. The analysis was repeated in subcohorts of candidates at lower risk for significant comorbidities, activated on the waiting list after 2007, or unsensitized at activation. Competing risks analyses were also conducted. Fully adjusted models showed increased hazard ratios (HRs [95% confidence intervals]) for all-cause mortality (HR, 1.02 [95% CI, 0.99 to 1.06]; HR, 1.11 [95% CI,1.07 to 1.16]; and HR,1.21 [95% CI,1.15 to 1.27]) and cardiovascular mortality (HR, 1.05 [95% CI,1.00 to 1.10]; HR,1.11 [95% CI,1.05 to 1.18]; and HR,1.21 [95% CI,1.12 to 1.31]) in PRA 1%-19%, PRA 20%-79%, and PRA 80%-100% categories compared with PRA 0%, respectively. Associations between PRA and the study outcomes were accentuated in competing risks models and in lower-risk patients and persisted in other subcohorts. Our findings suggest that PRA is an independent predictor of mortality in wait-listed kidney transplant candidates. The mechanisms by which PRA confers an incremental mortality risk in sensitized patients, and the role of transplantation in modifying this risk, warrant further study.

Equipoise: ethical, scientific, and clinical trial design considerations for compatible pair participation in kidney exchange programs

Compatible living donor/recipient pair participation (CPP) in kidney exchange (KE) transplantation may substantially increase transplant volumes and significantly mitigate the O blood group donor shortage in KE. Initial ethical analysis did not support CPP for two primary reasons: (1) KE would be "unbalanced," and (2) the possibility of undue influence experienced by the compatible pair living donor. Recent developments with CPP (modeling studies and small clinical experiences), have demonstrated substantial potential for increasing KE volumes. This encouraged us to reconsider initial ethical concerns, with a focus on the potential for a design of a prospective CPP clinical trial. This ethical reconsideration led us to conclude that the concept of unbalanced kidney exchanges (manifested primarily by differential benefit between compatible and incompatible pairs) is no longer as clear cut as originally conceived. In addition, application of two concepts substantially diminishes ethical concerns including: (1) "quasi-compatible" pairs, and (2) a priori definition of mitigating factors. We conclude that genuine uncertainty exists regarding whether kidney exchange is best performed with or without compatible pair participation and that a clinical trial is therefore warranted.

Living Donor Kidney Transplantation: Facilitating Education about Live Kidney Donation--Recommendations from a Consensus Conference

The Best Practice in Live Kidney Donation Consensus Conference held in June of 2014 included the Best Practices in Living Donor Education Workgroup, whose charge was to identify best practice strategies in education of living donors, community outreach initiatives, commercial media, solicitation, and state registries. The workgroup's goal was to identify critical content to include in living kidney donor education and best methods to deliver educational content. A detailed summary of considerations regarding educational content issues for potential living kidney donors is presented, including the consensus that was reached. Educational topics that may require updating on the basis of emerging studies on living kidney donor health outcomes are also presented. Enhancing the educational process is important for increasing living donor comprehension to optimize informed decision-making.

Clinical outcomes in Asian elderly kidney transplant recipients: a multicenter cohort study

BACKGROUND

The kidney transplantation rate in elderly patients is increasing rapidly. However, the clinical outcomes of kidney transplantation in elderly patients have not yet been thoroughly evaluated.

METHODS

This multicenter cohort study included adult kidney transplant recipients (KTRs) admitted to five major tertiary hospitals in Korea between 1997 and 2012. A total of 3,565 adult participants were enrolled. Patient survival, allograft survival, and biopsy-proven acute rejection (BPAR) of 242 elderly recipients (≥ 60 years) were assessed and compared with those of a younger population.

RESULTS

Patients were divided into five groups according to age at time of transplantation. The proportion of elderly patients was 6.7 % (mean age, 63.1 ± 2.7 years; n = 242). The numbers of male patients (69.4%), those with diabetes mellitus history (36.3%), and those with pretransplantation ischemic heart disease history (17.7%) were significantly higher in the elderly group than in the younger age groups. Elderly patients were more likely to receive a cadaveric kidney, and overall mortality rates were significantly higher in the elderly patients (1-year survival 93.3%, 5-year survival 91.3%). However, death-censored allograft survival rate and BPAR were not affected by patient age (P = .104 and .501, respectively). Among the elderly, BPAR and female donors were independent risk factors for allograft loss.

CONCLUSION

The overall survival rate of the elderly KTRs was significantly lower than that of younger KTRs. However, the death-censored allograft survival rate did not differ between groups. Kidney transplantation should not be stagnated especially in elderly patients with end-stage renal disease.

The Outcomes of Living Kidney Donation from Medically Complex Donors: Implications for the Donor and the Recipient

Living kidney donation is an important option for patients with end-stage renal disease (ESRD), and has improved life expectancy and quality for patients otherwise requiring maintenance dialysis or deceased-donor transplantation. Given the favorable outcomes of live donation and the shortage of organs to transplant, individuals with potentially unfavorable demographic and clinical characteristics are increasingly being permitted to donate kidneys. While this trend has successfully expanded the live donor pool, it has raised concerns as to which acceptance criteria are safe. This review aims to summarize the existing literature on the outcomes of transplantation from medically complex, living kidney donors, including both donor and recipient outcomes when available.

Effect of donor-recipient age difference on long-term graft survival in living kidney transplantation

PURPOSE

We aimed to examine the influence of donor age on living-donor kidney transplantation (KTx), particularly with regard to long-term graft survival in young recipients with aged kidney grafts.

METHODS

Between 1988 and 2012, 287 living-donor KTxs were performed in our center. The recipients were divided into 3 groups according to age in years: under 30 (young), 30-49 (middle-aged), and over 50 (old). The data regarding the influence of kidneys from donors aged over 50 years were retrospectively analyzed.

RESULTS

Graft survival at 1, 5, 10, and 15 years was 94.7, 94.7, 90.2, and 75.2%, respectively, in young recipients who received grafts from donors aged under 50 years, and 96.4, 91.9, 65.4, and 41.4%, respectively, in young recipients who received grafts from donors aged over 50 years (P = 0.023). In contrast, there were no significant differences regarding graft survival and donor age in the middle-aged and old recipient groups. Multivariate analysis revealed that young recipient and rejection episode were significant predictors of graft loss in transplantation from older donors. Histological examination revealed significant age-related changes in the grafts before transplant and a significant higher rate of glomerular hypertrophy at the 1-month protocol biopsy in young recipients with aged kidney grafts.

CONCLUSIONS

Kidney grafts from older living donors affected long-term graft survival in young recipients. In addition to the damage from rejection, aged kidney grafts, which have less nephron mass, may have a limited capacity to appropriately respond to increases in physiological or metabolic demands of young recipients, leading to a greater reduction in renal function.

Does donor-recipient age difference matter in outcome of kidney transplantation? Implications for kidney paired donation

BACKGROUND

Kidney paired donation (KPD) is a rapidly growing modality for facilitating living donor kidney transplantation (LDKTx) for patients who are incompatible with their healthy, willing and living donor. The impact of donor-recipient age difference on long and short-term graft and patient survivals in LDKTx is still uncertain.

METHODS

A total of 1502 LDKTx recipients who received regular follow-up in our center from 1999 to 2012 were studied. Donor-recipient age difference was divided into subgroups (donor-recipient 0-10, 11-20, 0-20, 21-30, 31-40, and 21-40 years). Outcome measures included death censored graft, patient survival and acute rejection rate.

RESULTS

The 1-, 5-, 10-year patient survival of the donor-recipient age difference ≤20 years group showed no difference compared with the age difference >20 years group (94.5%, 83.2%, 71.9% and 95.2%, 86%, 77.8%, p = 0.053). The 1-, 5-, 10-year graft survival of the donor-recipient age difference ≤20 years group showed no difference compared with the age difference >20 years group (94.6%, 81.6%, 72.1% and 94%, 80%, 72.2%, p = 0.989). The rejection were also similar (17.5% vs. 16.5%, p > 0.05). There was no statistically significant difference in graft survival and acute rejection rate in all subgroups.

CONCLUSIONS

Older donors (usually within families) are not associated with worse outcome is reassuring. KPD should not be prohibited due to high donor-recipient age difference, when size of donor pool is small as in single center KPD program.

Access to renal transplantation for the elderly in the face of new allocation policy: a review of contemporary perspectives on "older" issues

The benefits of renal transplantation have been demonstrated to extend to the elderly. As a result, more seniors have been placed on the kidney transplant wait list and have received renal allografts in recent years. In June 2013 significant amendments to deceased donor kidney allocation policy were approved to be instituted in 2014 with the goal of increasing overall life years and graft years achieved compared to the current system. Going forward, it is conceivable that transplant centers may perceive a need to adjust practice patterns and modify evaluation and listing criteria for the elderly as the proportion of kidneys distributed to this segment of the wait list would potentially decrease under the new system, further increasing wait times. This review examines contemporary perspectives on access to transplantation for seniors and pertinent issues for this subgroup such as wait time, comorbidity, and evaluation and listing practices. Potential approaches to improve the evaluation of elderly patients being considered for transplant and to increase availability of expanded criteria donor (or higher kidney donor profile index) and living donor organ transplant opportunities while maintaining acceptable outcomes for seniors are explored.

Renal transplantation from elderly living donors

Acceptance of elderly living kidney donors remains controversial due to the higher incidence of comorbidity and greater risk of postoperative complications. This is a review of publications in the English language between 2000 and 2013 about renal transplantation from elderly living donors to determine trends and effects of donation, and the outcomes of such transplantation. The last decade witnessed a 50% increase in living kidney donor transplants, with a disproportionate increase in donors >60 years. There is no accelerated loss of kidney function following donation, and the incidence of established renal failure (ERF) and hypertension among donors is similar to that of the general population. The overall incidence of ERF in living donors is about 0.134 per 1000 years. Elderly donors require rigorous assessment and should have a predicted glomerular filtration rate of at least 37.5 mL/min/1.73 m(2) at the age of 80. Though elderly donors had lower glomerular filtration rate before donation, proportionate decline after donation was similar in both young and elderly groups. The risks of delayed graft function, acute rejection, and graft failure in transplants from living donors >65 years are significantly higher than transplants from younger donors. A multicentred, long-term, and prospective database addressing the outcomes of kidneys from elderly living donors is recommended.

Impact of donor and recipient age difference on long-term allograft survival after living donor renal transplantation: analysis of 478 cases

INTRODUCTION

Either deceased or living-related renal transplantation constitutes the best therapeutic option for patients with end-stage renal disease. In this retrospective study, an attempt to identify parameters that affect allograft survival in living donor renal transplantation was made.

METHODS

Between January 2000 and July 2012, 478 adult patients received a renal transplant from a living-related donor in our center and their records were retrospectively reviewed in November 2012. Data concerning donor age, recipient age, donor/recipient age difference, donor/recipient gender, and ABO compatibility/incompatibility were recorded and associated with renal allograft survival rate.

RESULTS

Renal allograft survival rate was 96%, 89.5%, and 77.7% in the first, fifth, and 10th yr after transplantation, respectively. Only the difference between donor and recipient age was statistically significant in relation to graft survival. In cases with age difference >13 yr, graft survival rate was lower from the third yr onward.

CONCLUSIONS

Only the age difference between donor and recipient exerts an adverse impact on graft outcome after living donor renal transplantation, whereas donor age, recipient age, donor/recipient gender, and ABO incompatibility do not significantly influence renal allograft survival.

Ten kidney paired donation transplantation on World Kidney Day 2013: raising awareness and time to take action to increase donor pool

BACKGROUND

Kidney paired donation (KPD) is feasible for any center that performs living related donor renal transplantation (LRDRTx). Lack of awareness, counseling and participation are important hurdles in KPD patients with incompatible donors.

MATERIALS AND METHODS

This is an institutional review board approved study of 10 ESRD patients who consented to participate in the KPD transplantation at our center. All the surgeries were carried out on the same day at the same center on the occasion of World Kidney Day (WKD) (14 March 2013). All recipients had anatomic, functional and immunological similar donors.

RESULTS

KPD were performed to avoid blood group incompatibility (n = 8) or to avoid a positive crossmatch (n = 2). None of the patients experienced delayed graft function and surgical complications. At 3 month follow-up, median serum creatinine was 1 (range 0.6 to 1.25) mg/dL and two patients developed allograft biopsy-proven acute rejection and responded to antirejection therapy. Due to impact of our awareness activity, 20 more KPD patients are medically fit for transplantation and waiting for permission from the authorization committee before transplantation.

CONCLUSION

This is a report of 10 simultaneous KPD transplantations in a single day in a single centre on WKD raising awareness of KPD. KPD is viable, legal and rapidly growing modality for facilitating LRDRTx for patients who are incompatible with their healthy, willing LRD.

Prevalence and predictors of abdominal aortic calcification in healthy living kidney donors

BACKGROUND

Vascular calcification (VC) is common and is both a marker and a cause of increased cardiovascular morbidity and mortality, especially so in chronic kidney disease (CKD) patients. Renal transplantation is the cornerstone of the successful long-term management of CKD, and in order to satisfy transplantation needs, more use is made now of living kidney donors (LKD). Prior to selection for transplantation, much screening of potential LKD takes place, including for cardiovascular issues. It is not known; however, how much these potentially healthy LKD may be prone to clinically silent VC.

METHODS

We identified 103 living kidney donors from 2011 renal transplant records. Abdominal aortic calcification (AAC) was assessed using existing abdominal CT imaging using multi-channel CT aortograms (used primarily to assess renal vascular anatomy). Using these CT scans, manual calcium scoring was undertaken to calculate total aortic calcium load (AAC severity score). The prevalence, severity and associations of AAC between calcified and non-calcified donors were then compared.

RESULTS

A total of 103 donors were identified from records. Ninety three of these had detailed clinical records to complement their CT scans. Fifty of ninety-three donors were male, and the mean age was 45.9 ± 1.8 years. Mean MDRD eGFR was 88.73 ± 2.97 ml/min/1.73 m(2). 7.14 ± 3.07 % of the aorta in these donors was calcified with a mean AAC severity score of 0.98 ± 0.56. In kidney donors >50 years of age, there was significantly more AAC than in those <50: 2.47 ± 1.56 versus 0.31 ± 0.29, p < 0.001. There was no relationship between the presence or severity of aortic VC and donor GFR, systolic blood pressure, pulse pressure, calcium-phosphate product or smoking.

CONCLUSIONS

AAC prevalence, patterns and severity in this important donor population have not previously been described in the literature. There was relatively little VC in what would be regarded as a "healthy" donor population. VC was more common with age, but the other possible risk factors for the presence or severity of VC did not impact on overall AAC scores. VC did not influence vascular stiffness as represented by pulse pressure. Following the evolution of AAC over time in those who have donated a kidney, and lost some global renal function as a consequence, would be of considerable interest.