Randall S. Sung

Organ Donation and Utilization in the United States, 1996-2005

The success of clinical transplantation as a therapy for end‐stage organ failure is limited by the availability of suitable organs for transplant. This article discusses continued efforts by the transplant community to collaboratively improve the organ supply. There were 7593 deceased organ donors in 2005. This represents an all‐time high and a 6% increase over 2004. Increases were noted in deceased organ donation of all types of organs; notable is the increase in lung donation, which occurred in 17% of all deceased donors. The percentage of deceased donations that occurred following cardiac death has also reached a new high at 7%. The number of living donors decreased by 2%, from 7003 in 2004 to 6895 in 2005. This article discusses the continued efforts of the Organ Donation Breakthrough Collaborative and the Organ Transplantation Breakthrough Collaborative to support organ recovery and use and to encourage the expectation that for every deceased donor, all organs will be placed and transplanted.

A comprehensive risk quantification score for deceased donor kidneys: the kidney donor risk index.

Background. We propose a continuous kidney donor risk index (KDRI) for deceased donor kidneys, combining donor and transplant variables to quantify graft failure risk. Methods. By using national data from 1995 to 2005, we analyzed 69,440 first-time, kidney-only, deceased donor adult transplants. Cox regression was used to model the risk of death or graft loss, based on donor and transplant factors, adjusting for recipient factors. The proposed KDRI includes 14 donor and transplant factors, each found to be independently associated with graft failure or death: donor age, race, history of hypertension, history of diabetes, serum creatinine, cerebrovascular cause of death, height, weight, donation after cardiac death, hepatitis C virus status, human leukocyte antigen-B and DR mismatch, cold ischemia time, and double or en bloc transplant. The KDRI reflects the rate of graft failure relative to that of a healthy 40-year-old donor. Results. Transplants of kidneys in the highest KDRI quintile (>1.45) had an adjusted 5-year graft survival of 63%, compared with 82% and 79% in the two lowest KDRI quintiles (<0.79 and 0.79–<0.96, respectively). There is a considerable overlap in the KDRI distribution by expanded and nonexpanded criteria donor classification. Conclusions. The graded impact of KDRI on graft outcome makes it a useful decision-making tool at the time of the deceased donor kidney offer.

Proceedings of Consensus Conference on Simultaneous Liver Kidney Transplantation (SLK)

A consensus conference sponsored by the American Society of Transplant Surgeons (ASTS), American Society of Transplantation (AST), United Network for Organ Sharing (UNOS) and American Society of Nephrology (ASN) convened to examine simultaneous liver‐kidney transplantation (SLK). Directors from the 25 largest liver transplant programs along with speakers with recognized expertise attended. The purposes of this conference were to propose indications for SLK, to establish a prospective data registry and, most importantly, to recommend standard listing criteria for these patients. Scientific registry of transplant recipients data, and single center data regarding chronic kidney disease (CKD) and acute kidney injury (AKI) in conjunction with liver failure as a basis for SLK was presented and discussed. The consensus was that Regional Review Boards (RRB) should determine listing for SLK, as with other MELD exceptions, with automatic approval for: (i) End‐stage renal disease with cirrhosis and symptomatic portal hypertension or hepatic vein wedge pressure gradient ≥ 10 mm Hg (ii) Liver failure and CKD with GFR ≤ 30 mL/min (iii) AKI or hepatorenal syndrome with creatinine ≥ 2.0 mg/dL and dialysis ≥ 8 weeks (iv) Liver failure and CKD and biopsy demonstrating > 30% glomerulosclerosis or 30% fibrosis. The RRB would evaluate all other requests to determine appropriateness.

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.

Determinants of discard of expanded criteria donor kidneys: Impact of biopsy and machine perfusion

We examined factors associated with expanded criteria donor (ECD) kidney discard. Scientific Registry of Transplant Recipients (SRTR)/Organ Procurement and Transplantation Network (OPTN) data were examined for donor factors using logistic regression to determine the adjusted odds ratio (AOR) of discard of kidneys recovered between October 1999 and June 2005. Logistic and Cox regression models were used to determine associations with delayed graft function (DGF) and graft failure. Of the 12 536 recovered ECD kidneys, 5139 (41%) were discarded. Both the performance of a biopsy (AOR = 1.21, p = 0.02) and the degree of glomerulosclerosis (GS) on biopsy were significantly associated with increased odds of discard. GS was not consistently associated with DGF or graft failure. The discard rate of pumped ECD kidneys was 29.7% versus 43.6% for unpumped (AOR = 0.52, p < 0.0001). Among pumped kidneys, those with resistances of 0.26–0.38 and >0.38 mmHg/mL/min were discarded more than those with resistances of 0.18–0.25 mmHg/mL/min (AOR = 2.5 and 7.9, respectively). Among ECD kidneys, pumped kidneys were less likely to have DGF (AOR = 0.59, p < 0.0001) but not graft failure (RR = 0.9, p = 0.27). Biopsy findings and machine perfusion are important correlates of ECD kidney discard; corresponding associations with graft failure require further study.

Simultaneous liver-kidney transplantation: evaluation to decision making.

Questions about appropriate allocation of simultaneous liver and kidney transplants (SLK) are being asked because kidney dysfunction in the context of liver failure enhances access to deceased donor organs. There is specific concern that some patients who undergo combined liver and kidney transplantation may have reversible renal failure. There is also concern that liver transplants are placed prematurely in those with end‐stage renal disease. Thus to assure allocation of transplants only to those truly in need, the transplant community met in March 2006 to review post‐MELD (model for end‐stage liver disease) data on the impact of renal function on liver waitlist and transplant outcomes and the results of SLK.

Simultaneous Liver-Kidney Transplantation Summit: Current State and Future Directions

Although previous consensus recommendations have helped define patients who would benefit from simultaneous liver–kidney transplantation (SLK), there is a current need to reassess published guidelines for SLK because of continuing increase in proportion of liver transplant candidates with renal dysfunction and ongoing donor organ shortage. The purpose of this consensus meeting was to critically evaluate published and registry data regarding patient and renal outcomes following liver transplantation alone or SLK in liver transplant recipients with renal dysfunction. Modifications to the current guidelines for SLK and a research agenda were proposed.

Current status of kidney and pancreas transplantation in the United States, 1994-2003

This article reviews the OPTN/SRTR data collected on kidney and pancreas transplantation during 2003 in the context of trends over the past decade. Overall, the transplant community continued to struggle to meet the increasing demand for kidney and pancreas transplantation. The number of new wait‐listed kidney registrants under the age of 50 has remained relatively stable since 1994, but the number of new registrants aged 50 to 64 has doubled. However, there was only a 2.3% increase in the total number of kidney transplants performed in 2003. Expanded criteria donor kidneys made up 20% of all recovered kidneys and 16% of all transplants performed, compared with 15% in the prior year. In May 2003, new rules were implemented to promote equity in kidney organ allocation. These changes seem to have improved access for historically disadvantaged groups, though they have reduced the quality of HLA matching. The effects on long‐term outcomes have yet to be measured. Although the majority of SPK recipients are white (82%), the percentage of simultaneous kidney‐pancreas recipients who are African‐American has increased from 9% in 2000 to 16% in 2003. The percentage of Hispanic/Latino recipients increased from 5% to 9% over the same period.

Systematic Evaluation of Pancreas Allograft Quality, Outcomes and Geographic Variation in Utilization

Pancreas allograft acceptance is markedly more selective than other solid organs. The number of pancreata recovered is insufficient to meet the demand for pancreas transplants (PTx), particularly for patients awaiting simultaneous kidney‐pancreas (SPK) transplant. Development of a pancreas donor risk index (PDRI) to identify factors associated with an increased risk of allograft failure in the context of SPK, pancreas after kidney (PAK) or pancreas transplant alone (PTA), and to assess variation in allograft utilization by geography and center volume was undertaken. Retrospective analysis of all PTx performed from 2000 to 2006 (n = 9401) was performed using Cox regression controlling for donor and recipient characteristics. Ten donor variables and one transplant factor (ischemia time) were subsequently combined into the PDRI. Increased PDRI was associated with a significant, graded reduction in 1‐year pancreas graft survival. Recipients of PTAs or PAKs whose organs came from donors with an elevated PDRI (1.57–2.11) experienced a lower rate of 1‐year graft survival (77%) compared with SPK transplant recipients (88%). Pancreas allograft acceptance varied significantly by region particularly for PAK/PTA transplants (p < 0.0001). This analysis demonstrates the potential value of the PDRI to inform organ acceptance and potentially improve the utilization of higher risk organs in appropriate clinical settings.

Kidney and Pancreas Transplantation in the United States, 1995–2004

This article examines OPTN/SRTR data on kidney and pancreas transplantation for 2004 and the previous decade, and discusses recent changes in kidney‐pancreas (KP) allocation policy and emerging issues in kidney donation after cardiac death (DCD). Although the number of kidney donors continues to increase, new waiting list registrations again outpaced the number of kidney transplants performed, rising by 11% between 2003 and 2004 and contributing to a 1‐year increase of 8% in the number of patients active on the waiting list. DCD has increased steadily since 2000; 39% more DCD transplants were performed in 2004 than 2003. Both deceased donor and living donor kidney graft survival rates remain excellent and are improving. The number of people living with a functioning kidney transplant doubled between 1995 and 2004, to 101 440 with a functioning kidney‐alone and 7213 with a functioning KP. Health care providers in all settings are more likely to be exposed to these transplant recipients. Patient survival following simultaneous pancreas‐kidney (SPK) transplantation is excellent and has improved incrementally since 1995; death rates in the first year fell from 60 per 1000 patient‐years at risk in 2001 to 45 in 2003. The number of solitary pancreas transplants increased dramatically in 2004.