OPTN/SRTR 2019 Annual Data Report: Kidney

Despite the ongoing severe shortage of available kidney grafts relative to candidates in need, data from 2019 reveal some promising trends. After remaining relatively stagnant for many years, the number of kidney transplants has increased each year since 2015, reaching the highest annual count to date of 24,273 in 2019. The number of patients waiting for a kidney transplant in the United States was relatively stable, despite an increase in the number of new candidates added in 2019 and a decrease in patients removed from the waiting list owing to death or deteriorating medical condition. However, these encouraging trends are tempered by ongoing challenges. Nationwide, only a quarter of waitlisted patients receive a deceased-donor kidney transplant within 5 years, and this proportion varies dramatically by donation service area, from 15.5% to 67.8%. The non-utilization (discard) rate of recovered organs remains at 20.1%, despite adramatic decline in the discard of organs from hepatitis C-positive donors. Non-utilization rates remain particularly high for Kidney Donor Profile Index ≥85% kidneys and kidneys from which a biopsy specimen was obtained. While the number of living-donor transplants increased again in 2019, only a small proportion of the waiting list receives living-donor transplants each year, and racial disparities in living-donor transplant access persist. As both graft and patient survival continue to improve incrementally, the total number of living kidney transplant recipients with a functioning graft is anticipated to exceed 250,000 in the next 1-2 years. Over the past decade, the total number of pediatric kidney transplants performed has remained stable. Despite numerous efforts, living donor kidney transplant remains low among pediatric recipients with continued racial disparities among recipients. Congenital anomalies of the kidney and urinary tract remain the leading cause of kidney disease. While most deceased donor recipients receive a kidney from a donor with KDPI less than 35%, the majority of pediatric recipients had four or more HLA mismatches. Graft survival continues to improve with superior outcomes for living donor recipients.     

Living donor kidney transplantation in a Veterans Administration medical center

BACKGROUND: A shortage of organ donors remains the major limiting factor in kidney transplantation. Living donor renal transplantation, especially living-unrelated donors, may expand the donor pool by providing another source of excellent grafts. METHODS: Between 1983 and 2003, 109 living donor kidney transplants were performed. Potential donors were assessed with a standardized routine. Antithymocyte serum (N-ATS) and Basiliximab were used as induction agents. Sandimmune, Gengraf, Neoral, and Prograf were the main immunosuppressants with Immuran, Mycophenolate Mofetil, and steroids. Eighty-two percent of the recipients were from out of state. RESULTS: Seventy-eight percent of the living donors were from living-related donors and 22% were from living-unrelated donors. One- and three-year patient survival rates were 97.6% and 93.2% with 1- and 3-year graft survival rates of 93.2% and 88.3%, respectively. There were 6 delayed graft functions (5.5%), 16 acute cellular rejections (10%), and 10 chronic rejections (9%). Twelve patients died, 7 of them with a functioning graft. In the past 6 years (1997-2003), the number of living donor kidney transplants surpassed deceased donor kidney transplants. CONCLUSIONS: Because of the limited number of cadaveric kidneys available for transplant, living donors represent a valuable source, and the use of living-unrelated donors has produced an additional supply of organs. In our program, the proportion of living donors used for kidney transplant is comparable with other non-Veterans Administration programs and the survival of these allografts appears to be superior to deceased donor kidney transplants.     

Kidney and pancreas transplantation

Data from the Scientific Registry of Transplant Recipients offer a unique and comprehensive view of US trends in kidney and pancreas waiting list characteristics and outcomes, transplant recipient and donor characteristics, and patient and allograft survival. Important findings from our review of developments during 2002 and the decade's transplantation trends appear below.
The kidney waiting list has continued to grow, increasing from 47 830 in 2001 to 50 855 in 2002. This growth has occurred despite the increasing importance of living donor transplantation, which rose from 28% of total kidney transplants in 1993 to 43% in 2002.
Policies and procedures to expedite the allocation of expanded criteria donor (ECD) kidneys were developed and implemented during 2002, when 15% of deceased donor transplants were performed with ECD kidneys. Unadjusted 1- and 5-year deceased donor kidney allograft survivals were 81% and 51% for ECD kidney recipients, and 90% and 68% for non-ECD kidney recipients, respectively.
Although more patients have been placed on the simultaneous kidney-pancreas waiting list, the number of these transplants dropped from a peak of 970 in 1998 to 905 in 2002. This decline may be due to competition for organs from increasing numbers of isolated pancreas and islet transplants.     

Kidney and Pancreas Transplantation in the United States, 1996–2005

Kidney and pancreas transplantation in 2005 improved in quantity and outcome quality, despite the increasing average age of kidney graft recipients, with 56% aged 50 or older. Geography and ABO blood type contribute to the discrepancy in waiting time among the deceased donor (DD) candidates. Allocation policy changes are decreasing the median times to transplant for pediatric recipients. Overall, 6% more DD kidney transplants were performed in 2005 with slight increases in standard criteria donors (SCD) and expanded criteria donors (ECD). The largest increase (39%) was in donation after cardiac death (DCD) from non-ECD donors. These DCD, non-ECD kidneys had equivalent outcomes to SCD kidneys. 1-, 3- and 5-year unadjusted graft survival was 91%, 80% and 70% for non-ECD-DD transplants, 82%, 68% and 53% for ECD-DD grafts, and 95%, 88% and 80% for living donor kidney transplants. In 2005, 27% of patients were discharged without steroids compared to 3% in 1999. Acute rejection decreased to 11% in 2004. There was a slight increase in the number of simultaneous pancreas-kidney transplants (895), with fewer pancreas after kidney transplants (343 from 419 in 2004), and a stable number of pancreas alone transplants (129). Pancreas underutilization appears to be an ongoing issue.     

Kidney and Pancreas Transplantation in the United States, 1996–2005

Kidney and pancreas transplantation in 2005 improved in quantity and outcome quality, despite the increasing average age of kidney graft recipients, with 56% aged 50 or older. Geography and ABO blood type contribute to the discrepancy in waiting time among the deceased donor (DD) candidates. Allocation policy changes are decreasing the median times to transplant for pediatric recipients. Overall, 6% more DD kidney transplants were performed in 2005 with slight increases in standard criteria donors (SCD) and expanded criteria donors (ECD). The largest increase (39%) was in donation after cardiac death (DCD) from non‐ECD donors. These DCD, non‐ECD kidneys had equivalent outcomes to SCD kidneys. 1‐, 3‐ and 5‐year unadjusted graft survival was 91%, 80% and 70% for non‐ECD‐DD transplants, 82%, 68% and 53% for ECD‐DD grafts, and 95%, 88% and 80% for living donor kidney transplants. In 2005, 27% of patients were discharged without steroids compared to 3% in 1999. Acute rejection decreased to 11% in 2004. There was a slight increase in the number of simultaneous pancreas‐kidney transplants (895), with fewer pancreas after kidney transplants (343 from 419 in 2004), and a stable number of pancreas alone transplants (129). Pancreas underutilization appears to be an ongoing issue.     

Organ donation and utilization in the USA

The processes leading to donor identification, consent, organ procurement, and allocation continue to dominate debates and efforts in the field of transplantation. A considerable shortage of donors remains while the number of patients needing organ transplantation increases.
This article reviews the main trends in organ donation practices and procurement patterns from both deceased and living sources in the USA. Although there have been increases in living donation in recent years, 2002 witnessed a much more modest growth of 1%. Absolute declines in living liver and lung donation were also noted in 2002.
In 2002, the number of deceased donors increased by only 1.6% (101 donors). Increased donation from deceased donors provides more organs for transplantation than a comparable increase in living donation, because on average 3.6 organs are recovered from each deceased donor. The total number of organs recovered from deceased donors increased by 2.1% (462 organs). Poor organ quality continued to be the major reason given for nonrecovery of consented organs from deceased donors.
The kidney is the organ most likely to be discarded after recovery. Over the past decade the discard rate of recovered kidneys has increased from 6% to 11%. Many of these are expanded criteria donor kidneys.     

OPTN/SRTR 2017 Annual Data Report: Kidney

Many positive trends in kidney transplantation were notable in 2017. Deceased donor kidney transplant rates and counts continued to rise, the kidney transplant waiting list declined for the third year in a row after decades of growth, and both short‐ and long‐term allograft survival continued to improve year over year. In total, more than 220,000 patients were living in the United States with a functioning allograft. With 3 years of data available since implementation of the new kidney allocation system, better prediction of longer‐term results of the allocation policy changes became possible. The data also reveal several areas in need of improvement and attention. Overall, the challenge of providing adequate access to kidney transplant persisted nationally, with additional dramatic regional variation. The proportion of living donor kidney transplants in both adults and children continued to fall, and racial disparities in living donor kidney transplant grew in the past decade.     

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.     

Changes in Pediatric Renal Transplantation After Implementation of the Revised Deceased Donor Kidney Allocation Policy

In October 2005, the United Network for Organ Sharing (UNOS) implemented a revised allocation policy requiring that renal allografts from young deceased donors (DDs) (<35 years old) be offered preferentially to pediatric patients (<18 years old). In this study, we compare the pre- and postpolicy quarterly pediatric transplant statistics from 2000 to 2008. The mean number of pediatric renal transplants with young DDs increased after policy implementation from 62.8 to 133 per quarter (p < 0.001), reflecting a change in the proportion of all transplants from young DDs during the study period from 0.33 to 0.63 (p < 0.001). The mean number of pediatric renal transplants from old DDs (≥35 years old) decreased from 22.4 to 2.6 per quarter (p < 0.001). The proportion of all pediatric renal transplants from living donors decreased from 0.55 to 0.35 (p < 0.001). The proportion from young DDs with five or six mismatched human leukocyte antigen (HLA) loci increased from 0.16 to 0.36 (p < 0.001) while those with 0 to 4 HLA mismatches increased from 0.18 to 0.27 (p < 0.001). Revision of UNOS policy has increased the number of pediatric renal transplants with allografts from young DDs, while increasing HLA-mismatched allografts and decreasing the number from living donors.     

Lack of impact of human leukocyte antigen matching in living donor kidney transplantation: experience at Akdeniz University

Lack of expansion of the deceased donor supply has resulted in a severe shortage of organs worldwide. Spousal donors are one possible alternative organ source for patients on the kidney transplant waiting list. Despite human lymphocyte antigen (HLA) matching between recipients and unrelated donors being poor, the reported survival rates for these grafts, including spouses, are comparable to those for grafts from living related donors and higher than those for deceased donor kidneys. In 2000, our renal transplantation program began accepting living donor-recipient pairs with one or zero HLA matches. The purpose of this study was to assess this policy for accepting living unrelated donors. The 3-year graft survival rates for the transplants from living unrelated donors were similar to that for transplants from living related donors (log-rank = 0.078). The number of HLA mismatches did not significantly influence the survival rates for either of these groups of living donor transplants. Multivariate analysis revealed that dialysis duration (P = .057) and recipient age (P = .066) negatively influenced patient survival in living donor kidney transplantation. The graft and patient survival rates for the donor transplantations were higher than those for deceased donor transplantations. In light of these findings and considering the increasing problem of organ shortage, we conclude that living unrelated kidney transplantation should be performed, with strict guidelines. Spousal donation is the most favorable form of living unrelated renal transplantation.     

Optimizing outcomes by preconditioning the donor

The criteria that define a so-called “marginal donor” kidney have been standardized since 2002. However, every transplant center must establish its own guidelines on organ acceptability. An expanded criteria donor (ECD) kidney is age at least 60 years, or 50 to 59 years with at least two of three specified comorbidities. Cadaveric kidneys have shown worse functional and survival outcomes compared with those from living donors. Thus, all efforts should be made to minimize the effects of ischemia on standard, non-heart-beating or ECD cadaveric donor kidneys. Because of an increasing shortfall between the diminishing number of deceased donor organs available and the increasing waiting lists, an increasing number of living donor transplantations are being performed in Europe. Among deceased donor kidneys, the largest percentage corresponds to ECD—aged or comorbidity donors—and donors after cardiac death. The results of transplants with kidneys from donors over 65 years are 10% to 15% lower than those from younger donors. Older donors present more comorbidities; however, acceptable results may be obtained with careful selection and shortened cold ischemic times. If the transplant center uses these donors to expand the pool of available organs, the donor must be evaluated according to age, vascular condition, renal function, and comorbidity. If the donor is accepted, suitable questions are: Has the potential donor undergone maneuvers to improve the quality of the kidneys? Which kind of approaches should we perform? Should we only use the biopsy information for a decision?     

Solid-organ Transplants From Living Donors: Cumulative United States Experience on 140,156 Living Donor Transplants Over 28 Years

Background

Transplantation of organs from living donors helps to decrease the organ shortage and shortens waiting times. Living donor (LD) transplantation is also generally associated with better outcomes. Unfortunately, there has been no comprehensive analysis and comparison of all types of solid-organ transplantation from living donors since the inception of the United Network for Organ Sharing (UNOS).

Differential effects of donor‐specific HLA antibodies in living versus deceased donor transplant

The presence of donor‐specific anti‐HLA antibodies (DSAs) is associated with increased risk of graft failure after kidney transplant. We hypothesized that DSAs against HLA class I, class II, or both classes indicate a different risk for graft loss between deceased and living donor transplant. In this study, we investigated the impact of pretransplant DSAs, by using single antigen bead assays, on long‐term graft survival in 3237 deceased and 1487 living donor kidney transplants with a negative complement‐dependent crossmatch. In living donor transplants, we found a limited effect on graft survival of DSAs against class I or II antigens after transplant. Class I and II DSAs combined resulted in decreased 10‐year graft survival (84% to 75%). In contrast, after deceased donor transplant, patients with class I or class II DSAs had a 10‐year graft survival of 59% and 60%, respectively, both significantly lower than the survival for patients without DSAs (76%). The combination of class I and II DSAs resulted in a 10‐year survival of 54% in deceased donor transplants. In conclusion, class I and II DSAs are a clear risk factor for graft loss in deceased donor transplants, while in living donor transplants, class I and II DSAs seem to be associated with an increased risk for graft failure, but this could not be assessed due to their low prevalence.     

Kidneys from Deceased Donors: Maximizing the Value of a Scarce Resource

Donor age is a significant risk factor for graft loss after kidney transplantation. We investigated the question whether significant graft years were being lost through transplantation of younger donor kidneys into older recipients with potentially shorter lifespans than the organs they receive. We examined patient and graft survival for deceased donor kidney transplants performed in the United States between the years 1990 and 2002 by Kaplan-Meier plots. We categorized the distribution of deceased donor kidneys by donor and recipient age. Subsequently, we calculated the actual and projected graft survival of transplanted kidneys from younger donors with the patient survival of transplant recipients of varying ages. Over the study period, 16.4% (9250) transplants from donors aged 15-50 were transplanted to recipients over the age of 60. At the same time, 73.6% of donors above the age of 50 were allocated to recipients under the age of 60. The graft survival of grafts from younger donors significantly exceeded the patient survival of recipients over the age of 60. The overall projected improvement in graft survival, by excluding transplantation of younger kidneys to older recipients, was approximately 3 years per transplant. Avoiding the allocation of young donor kidneys to elderly recipients, could have significantly increased the overall graft life, by a total 27,500 graft years, between 1990 and 2002, with projected cost savings of about 1.5 billion dollars.     

Current Kidney Allocation Rules and Their Impact on a Pediatric Transplant Center

In 2005, kidney allocation rules in the United States were updated to enhance access to kidneys from young adult deceased donors (DDs) for pediatric recipients. We studied how this rule change affected transplant activity at our pediatric center. We retrospectively compared kidney transplant activity at our center since the rule change (until December 31, 2007) to before the change (n = 36 each), focusing on those recipients directly affected by it, that is, younger than 18 years. There were no significant differences in recipients' age, gender or ethnicity before versus after the rule change. Percentages of preemptive transplants and retransplants were similar in both groups, as was the percentage of sensitized patients. There was a significant decrease in overall, but not DD, mean donor age. Mean wait time for DD kidneys decreased for pediatric recipients. Increases were found in percentage of DD transplants and in mean HLA mismatches after the rule change. Patient and short-term graft survival were not significantly different. These data suggest that the allocation rule change was not only followed by improvement in overall access to kidney transplantation for children, but also by decreases in living donor transplants and HLA matching. Larger studies are needed to evaluate the long-term impact of the change.     

Pediatric Kidney Transplantation—Living or Deceased Donor?

BackgroundKidney transplantation is ideal for children and adolescents with chronic end-stage renal disease because it offers better growth, development, and quality of life. Donor choice is vitally important in this age group, given the long life expectancy of these patients.MethodsA retrospective analysis of pediatric patients (<18 years) who underwent kidney transplantation from January 1999 to December/2018 was performed. Short- and long-term outcomes were compared between living and deceased donor transplants.ResultsWe included 59 pediatric kidney transplant recipients, 12 from a living donor and 47 from a deceased donor. Thirty-six (61.0%) patients were boys, and 5 (8.5%) had a retransplant. There were no differences between groups on sex, race, and weight of the recipient and donor, as well as the age and the etiology of the recipient's primary disease. Most recipients received induction immunosuppression with basiliximab and maintenance with triple therapy, with no differences between groups. Living donor transplants were mostly pre-emptive (58.3% vs 4.3%, P < .001) and had fewer HLA mismatches (≤3: 90.9% vs 13.0%, P < .001), older donors (38.4 vs 24.3 years, P < .001) and shorter hospital stays (8.8 vs 14.1 days, P = .004). There were no statistically significant differences regarding medical-surgical complications and graft or patient survival. However, we found that at 13 years post-transplant 91.7% of the living donor grafts were functioning vs 72.3% of the deceased donor grafts.ConclusionOur experience points out that a living donor graft in pediatric patients is associated with a higher probability of pre-emptive transplant, shorter hospital stay, greater HLA compatibility, and increased graft survival.     

Pediatric Transplantation in the United States, 1995–2004

This article reviews trends in pediatric solid organ transplantation over the last decade, as reflected in OPTN/SRTR data. In 2004, children younger than 18 years made up nearly 3% of the 86 378 candidates for organ transplantation and nearly 7% of the 27 031 organ transplant recipients. Children accounted for nearly 14% of the 7152 deceased organ donors. The transplant community recognizes important differences between pediatric and adult organ transplant recipients, including different etiologies of organ failure, surgical procedures that are more complex or technically challenging, effects of development on the pharmacokinetic properties of common immunosuppressants, unique immunological aspects of transplant in the developing immune system and increased susceptibility to posttransplant complications, particularly infectious diseases. For these reasons, and because of the impact of end-stage organ failure on growth and development, the transplant community has generally provided pediatric candidates with special consideration in the allocation of deceased donor organs. Outcomes following kidney, liver and heart transplantation in children often rank among the best. This article emphasizes that the prospects for solid organ transplantation in children, especially those aged 1–10 years are excellent. It also identifies themes warranting further consideration, including organ availability, adolescent survival and challenges facing pediatric transplant clinical research.     

OPTN/SRTR 2019 Annual Data Report: Deceased Organ Donors

SRTR uses data collected by OPTN to calculate metrics such as donation rate, organ yield, and rate of organs recovered for transplant but not transplanted. In 2019, there were 11,870 deceased donors, an increase from 10,721 in 2018; this number has been increasing since 2010. The number of deceased donor transplants increased to 32,313 in 2019, from 29,675 in 2018; this number has been increasing since 2012. The increase may be due in part to the rising number of deaths of young people due to the ongoing opioid epidemic. The number of organs transplanted included 17,425 kidneys, 1,018 pancreata, 8,275 livers, 81 intestines, 3,604 hearts, and 2,607 lungs. In 2019, 4,324 kidneys, 346 pancreata, 867 livers, 5 intestines, 31 hearts, and 148 lungs were discarded. These numbers suggest an opportunity to increase numbers of transplants by reducing discards.     

Kidney and Pancreas Transplantation in the United States, 1998–2007: Access for Patients with Diabetes and End-Stage Renal Disease

Although the number of candidates on the kidney transplant waiting list at year-end rose from 40 825 to 76 070 (86%) between 1998 and 2007, recent growth principally reflects increases in the number of patients in inactive status. The number of active patients increased by 'only' 4510 between 2002 and 2007, from 44 263 to 48 773. There were 6037 living donor and 10 082 deceased donor kidney transplants in 2007. Patient and allograft survival was best for recipients of living donor kidneys, least for expanded criteria donor (ECD) deceased donor kidneys, and intermediate for non-ECD deceased donor kidneys. The total number of pancreas transplants peaked at 1484 in 2004 and has since declined to 1331. Among pancreas recipients, those with simultaneous pancreas-kidney (SPK) transplants experienced the best pancreas graft survival rates: 86% at 1 year and 53% at 10 years. Between 1998 and 2006, among diabetic patients with end-stage renal disease (ESRD) who were under the age of 50 years, 23% of all and 62% of those waitlisted received a kidney-alone or SPK transplant. In contrast, 6% of diabetic patients aged 50–75 years with ESRD were transplanted, representing 46% of those waitlisted from this cohort. Access to kidney-alone or SPK transplantation varies widely by state.     

Living unrelated donor kidney transplantation

BACKGROUND: Living unrelated donors remain an underutilized resource, despite their high graft survival rates. In this article, we updated the long-term results of more than 2500 living unrelated donor transplants performed in the United States. METHODS: Between 1987 and 1998, 1765 spouse, 986 living unrelated, 27,535 living related, and 86,953 cadaver donor grafts were reported to the United Network for Organ Sharing Kidney Registry. Kaplan-Meier curves compared graft survival rates in stratified analyses, and a log-linear analysis adjusted donor-specific outcomes for the effects of 24 other transplant factors. RESULTS: The long-term survival rates for both spouse and living unrelated transplants were essentially the same (5-year graft survivals of 75 and 72% and half-lives of 14 and 13 years, respectively). The results were similar to that for parent donor grafts (5-year graft survival = 74% and half-life = 12 years) and were significantly (P = 0.003) better than cadaver donor grafts (5-year graft survival = 62% and half-life = 9 years). After adjusting for the presence of transplant factors known to influence survival rates, recipients of living unrelated donor kidney transplants still had superior outcomes compared with cadaver transplants. CONCLUSIONS: Living unrelated kidney donors represent the fastest growing donor source in the United States and provide excellent long-term results. Encouraging spouses to donate could remove nearly 15% of the patients from the UNOS waiting list, effectively increasing the number of available cadaveric organs.