Increasing the supply of kidneys for transplantation

Improving HLA matching in living donor kidney transplantation using kidney paired exchange program

BACKGROUND

The inclusion of compatible pairs within kidney paired exchange programs has been described as a way to enhance these programs. Improved immunological matching for the recipient in compatible pair has been described to be a possible benefit.

METHODS

The main purpose of our study was to determine if the introduction of compatible pairs in the Portuguese kidney paired exchange program would result in a better match for these patients, but also to assess if this strategy would increase the number of incompatible pairs with a possible match. We included 17 compatible pairs in kidney paired exchange pool of 35 pairs and performed an in-silico simulation determining HLA eplet mismatch load between the co-registered and matched pairs using HLA MatchMaker, version 3.0.

RESULTS

Our study showed that the inclusion of fully HLA-A, -B, -DR mismatched compatible pairs within the national Portuguese KEP increased matched rate within ICP (0.71%) and improved HLA eplet matching within compatible pairs. 16 of 17 (94.12%) of the CP obtained one or more transplants possibilities and 13 (81.25%) would have been transplanted with significantly lower HLA class I and class II total and antibody-verified eplet mismatch load (83.9 ± 16.9 vs. 59.8 ± 12.2, P = .002 and 30.1 ± 5.5 vs. 21.2 ± 3.0, P = .003, respectively).

CONCLUSIONS

This strategy is a viable alternative for compatible pairs seeking a better matched kidney and Portuguese KEP program should allow them this possibility.

Blood Pressure and Living Kidney Donors: A Clinical Perspective

Elevated blood pressure (BP), or “hypertension,” has been one of the main exclusion criteria for living kidney donation, as it is a risk factor for renal and cardiovascular disease. The effect of elevated BP in living kidney donors is not well studied or understood. The most current living kidney donation guidelines state that donors with a BP >140/90 mm Hg with 1–2 antihypertensive medications or evidence of end-organ damage should be excluded from living kidney donation. Yet, the definitions of “hypertension” have changed with the release of the American Heart Association (AHA)/American College of Cardiology (ACC) clinical practice guidelines suggesting that 120–129 mm Hg is elevated BP and Stage 1 hypertension is 130 mm Hg. However, the kidney function (in terms of estimated GFR) of “hypertensive” living kidney donors does not fare significantly worse postdonation compared with that of “normotensive” donors. In addition, even though living kidney donation itself is not considered to be a risk factor for developing hypertension, there exist certain risk factors (African American or Hispanic descent, obesity, age) that may increase the risk of living kidney donors developing elevated BP postdonation. The choice of BP targets and medications needs to be carefully individualized. In general, a BP <130/80 mm Hg is needed, along with lifestyle modifications.

Hypothermia and kidney: a focus on ischaemia-reperfusion injury

Cellular damage after reperfusion of ischaemic tissue is defined as ischaemia–reperfusion injury (IRI). Hypothermia is able to decrease oxygen consumption, preventing a rapid loss of mitochondrial activity. However, even though cooling can help to decrease the deleterious effects of ischaemia, the consequences are not exclusively beneficial, such that hypothermic storage is a compromise between benefits and harm. The present review details the relationship between renal IRI and hypothermia, describing the pathophysiology of IRI and hypothermic protection through experimental evidence. Although experimental models of renal IRI are a valuable tool for understanding the pathophysiology of renal ischaemia–reperfusion, the clinical transfer of experimental results has several limitations, particularly because of anatomical and physiological differences. In this review limitations of animal models but also hypothermia as a strategy to protect the kidney from IRI are discussed. We also attempt to describe three clinical scenarios where hypothermia is used in clinical settings of IRI: transplantation, deceased donors and post-cardiac arrest.

First Canadian experience with donation after cardiac death simultaneous pancreas and kidney transplants

BACKGROUND

Compared with neurologic determination of death (NDD) donor organs, donation after cardiac death (DCD) donor organs have traditionally been considered of inferior quality owing to warm ischemia experienced during procurement. We present, to our knowledge, the first analysis of simultaneous pancreas and kidney (SPK) transplants using DCD donor organs in Canada.

METHODS

We carried out a retrospective cohort study of SPK transplants from 13 DCD and 68 NDD donors performed between October 2008 and July 2016. In all patients immunosuppression was induced with thymoglobulin and continued with tacrolimus, mycophenolate mofetil and prednisone maintenance therapy.

RESULTS

Donor and recipient characteristics of DCD and NDD groups were similar with respect to age, sex, body mass index, kidney and pancreas cold ischemia times, and donor terminal creatinine. Mean DCD graft warm ischemia time was 0.5 (range 0.4-0.7) hours. Median follow-up was 2.2 (range 0.1-6.7) years and 2.7 (range 0.3-6.3) years for the DCD and NDD groups, respectively. The DCD and NDD groups were similar with regards to recipient percent panel reactive antibody and presence of human leukocyte antigen antibodies. The groups also received similar total doses of thymoglobulin. In total 38% of patients in the DCD group experienced renal delayed graft function (DGF) compared with 10% in the NDD group (p = 0.027). There were 7 cases of pancreas graft thrombosis requiring relaparotomy in the NDD group compared with none in the DCD group. No patients from either group required insulin at any time after transplant. Although the estimated glomerular filtration rate (eGFR) was lower in the DCD than the NDD group on postoperative days 7 and 14 (p = 0.025), no difference was noted on day 30 or through 4 years after transplant. No differences were seen between the groups with respect to amylase, lipase, or glycosated hemoglobin (HbA_1c) up to 4 years after transplant, or in kidney, pancreas, or patient survival at any time after transplant.

CONCLUSION

Our results show that, apart from a higher renal DGF rate, SPK transplants with DCD donor organs have comparable outcomes to standard transplants with NDD donor organs.

Ethical and legal issues related to the donation and use of nonstandard organs for transplants

Transplantation of nonstandard or expanded criteria donor organs creates several potential ethical and legal problems in terms of consent and liability, and new challenges for research and service development; it highlights the need for a system of organ donation that responds to an evolving ethical landscape and incorporates scientific innovation to meet the needs of recipients, but which also safeguards the interests and autonomy of the donor. In this article, the use of deceased donor organs for transplants that fail to meet standard donor criteria and the legitimacy of interventions and research aimed at optimizing their successful donation are discussed.

First global forum on education on organ donation and transplantation for schools

The Transplantation Society, in collaboration with the Canadian Society of Transplantation, organized a forum on education on ODT for schools. The forum included participants from around the world, school boards, and representatives from different religions. Participants presented on their countries' experience in the area of education on ODT. Working groups discussed about technologies for education, principles for sharing of resources globally, and relationships between education, and health authorities and non-governmental organizations. The forum concluded with a discussion about how to best help existing programs and those wishing to start educational programs on ODT.

Kidney donation after cardiac death

There is continuing disparity between demand for and supply of kidneys for transplantation. This review describes the current state of kidney donation after cardiac death (DCD) and provides recommendations for a way forward. The conversion rate for potential DCD donors varies from 40%-80%. Compared to controlled DCD, uncontrolled DCD is more labour intensive, has a lower conversion rate and a higher discard rate. The super-rapid laparotomy technique involving direct aortic cannulation is preferred over in situ perfusion in controlled DCD donation and is associated with lower kidney discard rates, shorter warm ischaemia times and higher graft survival rates. DCD kidneys showed a 5.73-fold increase in the incidence of delayed graft function (DGF) and a higher primary non function rate compared to donation after brain death kidneys, but the long term graft function is equivalent between the two. The cold ischaemia time is a controllable factor that significantly influences the outcome of allografts, for example, limiting it to < 12 h markedly reduces DGF. DCD kidneys from donors < 50 function like standard criteria kidneys and should be viewed as such. As the majority of DCD kidneys are from controlled donation, incorporation of uncontrolled donation will expand the donor pool. Efforts to maximise the supply of kidneys from DCD include: implementing organ recovery from emergency department setting; improving family consent rate; utilising technological developments to optimise organs either prior to recovery from donors or during storage; improving organ allocation to ensure best utility; and improving viability testing to reduce primary non function.

Social deprivation, ethnicity, and uptake of living kidney donor transplantation in the United Kingdom

BACKGROUND

Socioeconomic disparities and their contribution to the ethnic differences in living kidney donor transplantation have not been adequately studied.

METHODS

A total of 12,282 patients aged 18 to 69 years starting renal replacement therapy (January 1, 1997, to December 31, 2004) in the United Kingdom were included. Logistic regression models were used to examine probability of living donor transplantation within 3 years of renal replacement therapy. The effect of area deprivation (Townsend index) was studied among whites only adjusted for patient characteristics and the effect of ethnic origin (South Asians and blacks compared with whites) was then examined among all patients adjusting for area deprivation.

RESULTS

Among whites, increasing social deprivation was associated with lower odds of living donor transplantation. In the fully adjusted model, odds ratio (OR) for the most deprived quintile was 0.40 (95% confidence interval [CI] 0.33, 0.49; P trend<0.0001) compared with the least deprived. These gradients were more pronounced among centers performing more live donor transplants (P value for interaction <0.0001). South Asians and blacks had lower odds of living donor transplantation compared with whites, but there was an interaction with age (P<0.0001), so that this disparity was observed only in those younger than 50 years (blacks: OR, 0.31; 95% CI, 0.18, 0.54; South Asians: OR, 0.55; 95% CI, 0.34, 0.90; P value <0.0001).

CONCLUSIONS

Socially deprived and younger ethnic minority patients have lower probability of living kidney donor transplantation. The extent to which these inequalities reflect modifiable societal healthcare system barriers and donor/recipient factors requires further study.

Determinants of the decision to accept a kidney from a donor at increased risk for blood-borne viral infection

BACKGROUND AND OBJECTIVES

The use of kidneys from donors at increased risk for viral infections (DIRVI) such as HIV could increase the number of transplants and decrease waiting times. This study aimed to identify the proportion of kidney transplant candidates that would accept a kidney from a DIRVI and the factors that influenced this decision.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Conjoint analysis was used to assess the conditions in which renal transplant candidates would accept a DIRVI kidney. Candidates completed 12 scenarios in which the waiting time for a kidney, the donor age as a surrogate for kidney quality, and the risk of contracting HIV were systematically varied.

RESULTS

Among 175 respondents, 42 (24.0%) rejected DIRVI kidneys under all conditions, 103 (58.9%) accepted DIRVI kidneys under some conditions, and 31 (17.7%) always accepted DIRVI kidneys. In multivariable logistic regression, patients were more likely to accept a DIRVI kidney when waiting time was longer, the donor was younger, and HIV risk was lower (P < 0.01 for each variable). Patients on dialysis (P < 0.01) and older patients (P = 0.04) more commonly accepted DIRVI kidneys, but self-rated sense of health was not associated with DIRVI kidney acceptance.

CONCLUSIONS

Most renal transplant candidates would accept a DIRVI kidney under some circumstances. These findings suggest that recipients can be allowed to make prospective choices regarding DIRVI kidney acceptance without hindering placement of these organs.

Living or deceased donor kidney transplantation: a comparison of results and survival rates among Iranian patients

OBJECTIVE

Kidney transplantation is the selective treatment of end-stage renal disease. Although most previous studies have concluded that living kidney donation achieves better graft survival, some factors may limit this type of donation. This study investigated the survival rates of living and deceased donor kidney transplantations among Iranian patients.

MATERIALS AND METHODS

The records of kidney transplantations up to year 2005 were used to compare 50 deceased (group I) with 50 living donor transplants (group II). The recipients were matched by transplantation time. We used SPSS version 15 software to analyze the data.

RESULTS

Group I patients included 28 males and 22 females of mean age of 38 +/- 13 years, while 26 males and 24 females in group II had a mean age of 34.6 +/- 14 years. The rejection and graft nephrectomy rates were significantly higher among group I than group II (P = .01, P = .02). The first-year graft survival was higher in group II (P = .001). The graft survival was significantly lower in recipients who needed a biopsy or dialysis (P = .006 and P = .02, respectively) and higher among those who had a urine volume >4200 mL within the first 24 hours after transplantation (P = .003). Patient survivals were not significantly different between the groups.

CONCLUSION

Living donor kidney transplantations showed higher graft survival and lower acute rejection rates compared with those from deceased donors.

Management of the kidney transplant recipient

The short-term outcomes of kidney transplant recipients have improved dramatically in the past 20 years, in large part resulting from the availability of more potent immunosuppressive drugs capable of preventing or treating acute allograft rejection. Ironically, side effects from these same immunosuppressants play a role in the long-term morbidity and mortality of this patient population. As kidney transplant recipients survive for longer periods of time with functioning allografts, primary care physicians will likely become more involved in their management, mandating at least a basic understanding of immunosuppression and its complications.

Arteriosclerosis in kidneys from healthy live donors: comparison of wedge and needle core perioperative biopsies

CONTEXT

Although risks associated with live kidney donation are low, there are few pathologic studies of kidneys from live donors, and possible risk factors for development of hypertension or renal insufficiency remain unknown. There are many studies of histopathologic changes in deceased donor kidneys and how these changes affect subsequent graft function; most are based on wedge rather than needle core biopsies.

OBJECTIVE

To examine the frequency and severity of arterial fibrointimal thickening and other pathologic lesions in kidneys from healthy live donors and compare wedge and needle core biopsies as methods for evaluating these changes.

DESIGN

For 36 of 332 live donor renal transplantations performed from January 2004 through November 2006, a wedge biopsy of the transplanted kidney was done prior to and/or after implantation, and a needle core biopsy was done postimplantation or during the ensuing 7 days. For these 36 allografts, we compared pathologic features of the wedge and core perioperative biopsies.

RESULTS

Findings on core and wedge biopsies were similar, except for arterial fibrointimal thickening. Moderate thickening (Banff cv2) was present on 13 core biopsies, and mild thickening (cv1) was present on another 10; by contrast, no wedge biopsies showed cv2 lesions, and only 8 showed cv1. Arterial thickening on core but not wedge biopsies correlated significantly with increasing patient age.

CONCLUSIONS

The findings indicate that needle core biopsies are superior to wedge biopsies for evaluating vascular changes in donor kidneys, and they suggest a need for studies correlating such changes with long-term outcomes of live donors, particularly older donors.

Is presumed consent the answer to organ shortages? No

The supply of donor organs cannot keep up with demand. Veronica English argues that assuming people want to donate unless there is contrary evidence will increase availability, but Linda Wright believes the problem is more complex