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Home , Cadaver, Kidney transplantation, Organ donation

SPECIAL ARTICLE J Am Soc Nephrol 10: 2237–2243, 1999

The Allocation of Kidneys for Transplantation in the : Consensus and Controversy

JOHN F. NEYLAN, MOHAMED H. SAYEGH, THOMAS M. COFFMAN, GABRIEL M. DANOVITCH, ALAN M. KRENSKY, TERRY B. STROM, LAURENCE A. TURKA, and WILLIAM E. HARMON, FOR THE ASN TRANSPLANT ADVISORY GROUP

The development of transplantation as a widely available 7,061 cadaver and 1,812 living donor transplants were per- and clinically effective has provided an enormous formed (3). Currently, there are 41,744 patients enrolled on the benefit for the care of patients with end-stage renal disease cadaver waiting list (a 200% increase), while only 8,938 ca- (ESRD). One-year cadaver donor survival rates have daver donor renal transplants (a 24% increase) were performed improved from 52% to nearly 90% between 1977 and 1998 in the United States last year (4) (Figure 3). The average (1,2). Such outcomes have encouraged more patients to request waiting time for cadaver donor renal transplants has increased transplantation as their preferred mode of therapy. Unfortu- to more than 1000 days, with some groups, such as African- nately, the number of cadaver donors has not increased at an Americans, waiting substantially longer. If the waiting list equivalent rate to meet the expanded demand. The problem is increases by 20% per year and the number of cadaveric compounded further by the increasing prevalence of patients transplants remains below 10,000 per year, it is anticipated that treated for ESRD (2) (Figure 1). The widening gap between the by 2010 the mean waiting time for a transplant will approach number of renal transplant candidates and available donors is 10 years, unless there are dramatic advances in xenotransplan- shown in Figure 2. As the imbalance between supply and tation or tissue engineering. demand worsens, the allocation of donor organs to recipients Partly as the result of this lengthening waiting period, the becomes an increasingly important issue and the subject of use of living donors, especially living unrelated donors, has increasing controversy. The factors that have influenced the increased dramatically. Living-donor kidney transplants ac- development of , recovery and allocation, and counted for 31% of all transplants in 1998 (4), and the number consequent access to renal transplantation in the United States of “emotionally related” donations has increased sevenfold in are complex. The present system is dependent on volunteerism, the past decade (3). In addition, expanded criteria of medical public trust, and a continued assessment of outcomes to acceptability of cadaveric donors have been utilized with achieve a difficult balance of equity and justice. greater frequency; and newer experiments, such as proposals This report summarizes the history and development of for donor exchanges between mismatched but oth- cadaver kidney allocation in the United States and is meant to erwise suitable living donor-recipient pairs (5), age matching serve as a background overview. The American Society of for elderly recipients (6–8), and paired kidney transplants (ASN), as a professional organization whose (9,10) have all occurred because of the increasing discrepancy members are responsible for patients who are dependent on the between the number of donors and candidates for kidney fair allocation of cadaver kidneys for transplantation, must transplantation. develop a position on this difficult issue. The ASN Transplant Advisory Group has initiated the process with this overview and proposes that the ASN develop an official position on Structure and History of Kidney Allocation kidney organ allocation by the year 2000. Organizations Organ Procurement Organizations (OPOs) developed in the Donor Shortage 1960s as a result of the increasing success in the transplantation At the end of 1988, there were 13,943 people waiting for of cadaveric kidneys. In the early days, these organizations cadaver kidney transplants in the United States. In that year, resulted from the voluntary collaborative efforts of multiple transplant programs in a localized geographic area. After the passage of federal law creating the entitlement pro- gram for patients with ESRD in 1972, the proliferation of Received June 23, 1999. Accepted July 16, 1999. as a federally funded therapy for ESRD Correspondence to Dr. William E. Harmon, Nephrology Division, Childrens and the consequent demand for more donor organs stimulated Hospital, 300 Longwood Avenue, HU 217, Boston, MA 02115. Phone: 617- 355-0129; Fax: 617-232-2949; E-mail: [email protected] a dramatic increase in the number of OPOs nationwide. In the 1046-6673/1010-2237 latter half of the 1970s, Medicare funding became available for Journal of the American Society of Nephrology independent as well as hospital-based OPOs, leading to further Copyright © 1999 by the American Society of Nephrology refinements of these operations. Today, there are 65 active 2238 Journal of the American Society of Nephrology J Am Soc Nephrol 10: 2237–2243, 1999

many states. Beginning January 1, 1996, the Health Care Financing Administration required that an OPO include an entire state or territory, or that it recover organs from at least 50 potential or 24 actual donors per calendar year (11). There appears to be variable performance of OPOs across the country when assessed according to the traditional, al- though increasingly contested, productivity measure of organs procured per million base population. Based on the 5,788 cadaveric donors from whom organs were recovered in 1998 and an estimate of the U.S. census at 272.6 million population, the national average is 21.2 donors per million population per Figure 1. Living end-stage renal disease (ESRD) patients on Decem- year. The wide range for individual OPOs varies from approx- f ber 31 by year and treatment modality. , number of patients; imately 10 to 40 donors per million. Some of the difference u, number of patients with functioning transplants. Adapted from may be related to substantial regional differences in medically reference (2). suitable organ donor candidates, differences in automobile fatality rates, and the incidence of and other trau- matic causes of . Also, there appear to be cultural differ- ences in attitudes toward donation as well as differences in permission rates between rural and urban areas. Thus, newer performance measures based instead on numbers of medically suitable candidates are being proposed to more accurately define OPO productivity. Nonetheless, it is clear that some OPOs have taken a leadership role in developing more inno- vative educational programs and in the implementation of new protocols, such as recovery of organs from non--beating donors (12–14). Comprehensive death audits of hospital records have yielded Figure 2. Number of candidates for cadaver kidney transplants (u) considerably higher estimates of medically suitable donors and the number of cadaver kidney donors (f) in the United States than the current national average, perhaps as high as 55 donors from 1988 to 1998. Each donor may contribute two kidneys, so the per million (15). Thus, actual conversion rates of suitable number of transplants is greater than the number of donors. Adapted donors may be less than 50% of the maximal potential. In from references (3) and (4). 1998, in an effort to enhance potential donor identification and conversion to actual organ recovery, the Department of Health and Services (DHHS) issued a rule for conditions of hospital participation in Medicare that required hospitals to notify OPOs of all potential . This rule was based on an experiment in that demonstrated enhanced donor identification and conversion when experienced OPO staff were able to contact donor families and direct the request for donation (16,17). Some have suggested that the 5.6% increase in cadaver donors for 1998 may be in part attributable to the implementation of this new rule nationwide. However, even with such measures in place, family refusals remain the most significant barrier to donation, turning down, on average, more than one out of every two requests for organ donation (18,19). f u Figure 3. Number of cadaver donor ( ) and living donor ( ) renal Public attitudes and behavior thus remain a significant hurdle. transplants performed in the United States from 1988 to 1998. Adapted from references (3) and (4). National Organ Transplant Act In 1984, Congress passed PL 98-507, known as the National Organ Transplant Act (NOTA), which prohibited the sale of OPOs servicing defined regions throughout the United States. human organs, established grants for OPOs, and called for the There is, however, no universally accepted structure for an establishment of a national system of organ sharing. In addi- OPO. For example, some OPOs service a small geographic tion, NOTA created a multidisciplinary task force to conduct area and a single transplant center, whereas other OPOs serve an examination of organ donation and transplantation. The task as many as six states or more than 15 transplant centers. In force’s extensive list of recommendations included the setting some areas of the country, there are multiple OPOs within one of performance standards for OPOs and transplant centers, as state or even one city, whereas in others a single OPO serves well as the establishment of protocols within hospitals dealing J Am Soc Nephrol 10: 2237–2243, 1999 Cadaver Kidney Allocation 2239 with and organ donation (20). One important outgrowth has been the Uniform Anatomical Gift Act, now established in every state, which maintains the right of every individual aged 18 years or older to donate organs or tissues for purposes including transplantation. The legislation further es- tablishes the right of the individual to designate such direction before death and validates the legality of such methods of declaration as the organ donor card. These declarations are also legally binding even when an attempted contravention by next of kin creates conflict.

Organ Procurement and Transplantation Network The Omnibus Budget Reconciliation Act of 1986 (PL 99- 509) established that all OPOs and transplant centers become part of a nationwide Organ Procurement and Transplantation Network (OPTN). The OPTN was charged with developing Figure 4. Map of United Network for Organ Sharing regions. From policy for allocation of cadaver source organs for transplanta- reference (3). tion. In addition, Congress authorized the creation of a scien- tific registry to track outcomes for all organ transplants per- formed in the United States. The contracts for both functions Organ Allocation Policies can be awarded individually, but the United Network for Organ Organ allocation policies have developed in a consensus Sharing (UNOS) successfully bid for that contract and has manner in an attempt to balance the competing principles of remained the provider to this day. UNOS had been established medical utility and fairness. The OPTN contractor and its in 1977 as an outgrowth of the Southeastern Organ Procure- committee structure have attempted to find appropriate factors ment Foundation (SEOPF), a confederation of transplant pro- to rank potential recipients of scarce transplantable organs grams sharing organs regionally via a computerized matching based on their likelihood of receiving an organ and their likely program. UNOS extended this concept to a national level as a outcomes after transplantation. For instance, the demonstration means to optimize matching strategies and improve the effi- of superior long-term graft survival with 6-antigen matched (or ciency of organ sharing. As the operation grew, UNOS created 0-antigen mismatched) kidneys has led to the mandated sharing The Kidney Center in 1982, renamed the Organ Center in of such organs on a national basis. Historically, these best- 1984, to reflect its expanded operations in other transplantable matched transplants made up approximately 5% of the total organs. This 24-hour operation coordinated the allocation of cadaver renal transplants, but this percentage has been growing available organs to the candidates listed in the computer and is currently 13.8% as the number of candidates and the records. With the award of the national OPTN contract, UNOS amount of time they wait is increasing. In the absence of such changed its structure to that of a nonprofit, private voluntary a match, the donor organ is allocated locally to ABO blood organization made up of transplant professionals and public group-compatible candidates prioritized on the basis of a com- members. UNOS is governed by a Board of Directors, which is puter algorithm that assigns points based on length of time currently composed of 40 individuals who represent diverse waiting, present state of alloimmunization, and the quality of HLA matching. Children are given preference and are awarded constituencies. All organ transplant programs are grouped into additional points based on their age at the time of listing. All 11 geographic regions (Figure 4), and a councilor from each of potential recipients with the same donor ABO blood type are those regions sits on the Board of Directors. The Board is ranked according to these parameters (Table 1), and the indi- composed also of representatives of patient groups, donor vidual ranked highest is the preferred potential recipient. Fac- families, histocompatibility laboratories, OPOs, and profes- tors such as unavailability, intercurrent illness, or a positive sional societies. Although all transplant programs belong to final crossmatch may come into play and lead to the designa- UNOS, their compliance with UNOS policies remains volun- tion of alternate candidates. In some OPOs, special consider- tary. UNOS does not have any statutory authority to enforce its ation is given to diabetic candidates for combined kidney- rules until the Secretary of DHHS approves such policies and transplantation, and one of the donor kidneys is by-laws, which has not yet happened. UNOS has established a allocated with a recovered pancreas. Scientific Registry to track data relating to organs procured and When a donor becomes available in a particular OPO, this their functional outcomes in transplant recipients (3). Organ- matching process is applied to the group of recipients listed by specific registries were created for each transplanted organ and the transplant hospitals within that OPO. As noted above, the were maintained by subcontractors. In the case of kidney size of OPOs and the number of potential recipients listed transplantation, the database is maintained at the University of within that OPO vary widely. If no suitable candidate exists at Los Angeles. within the OPO, the allocation is expanded to the region and 2240 Journal of the American Society of Nephrology J Am Soc Nephrol 10: 2237–2243, 1999

Table 1. UNOS point system for cadaver kidney allocationa

Category Points Assigned

Time of waiting 1 point assigned to the patient waiting the longest; fractions proportionately assigned to the remainder 1 additional point for each full year waiting Quality of antigen mismatch 7 points for zero B or DR mismatches 5 points for only1BorDRmismatch 2 points for only2BorDRmismatches Panel-reactive antibody 4 points, if the PRA is Ͼ80% and a crossmatch is negative Pediatric 4 points for age Ͻ11 years 3 points for age 11 years but Ͻ18 years

a UNOS, United Network for Organ Sharing; PRA, panel-reactive antibody. subsequently to the entire national list, if necessary, although tion injuries would, in turn, have a negative impact on patient practical time and logistical constraints must be weighed as and graft survivals. In addition, the increased transport and increasing cold time beyond 24 to 48 hours may lead laboratory costs of such a system, given present technologies, to poorer outcome (21–23). was deemed to be prohibitive. Although this single system is supposed to apply to the allocation of all cadaver kidneys, exceptions and designated Multiple Organ Transplants experimental allocation systems do exist (24). The exceptions Renal failure is a common feature of end-stage hepatic are generally categorized as Alternative Local Units (ALUs), (ESLD) and cardiac disease, and as the numbers of and variances, and sharing agreements. ALUs constitute subsec- heart transplants have increased so have the requirements for tions of OPOs, entire states, UNOS regions, or other geo- kidney transplants in combination (26,27). In 1997 the UNOS graphic areas that serve as the basis of local organ distribution database reported 145 kidney transplants performed in combi- rather than the recovering OPO. Variances are alternative point nation with other nonpancreatic organs and the numbers are systems that generally emphasize different components of the increasing. The kidney/liver combination (KLTx) accounted matching system, some giving greater weight to time on the for approximately 85% of these transplants (26). There has waiting list, panel-reactive antibody, or other matching strate- been controversy, however, regarding the necessity for KLTx gies. Sharing agreements occur between OPOs within or be- in patients with ESLD and potentially reversible renal dysfunc- tween a given UNOS region. All exceptions require ratification tion, often loosely designated as hepatorenal syndrome (HRS). by the Board of Directors of UNOS and are periodically Between 1988 and 1995, the renal diagnosis for 11.6% of all reviewed to ensure that they are maximizing the efficient use of KLTx was reported to be HRS, but for a further 33% the donor organs and that the allocation scheme is primarily pa- diagnosis was described as “other” or “unknown,” and many of tient-driven rather than transplant center-driven. these cases likely had potentially reversible causes of renal Allocation of kidneys according to the standard UNOS point failure. The overall mortality after for system provides no priority based on the medical condition of patients with a serum level Ͼ2 mg/dl is not im- the recipients who are all presumed to have access to chronic proved by KLTx as opposed to liver transplant alone (26), dialysis. Difficult decisions regarding the relative disability, although clearly there are some patients who develop irrevers- morbidity, and potential for rehabilitation of kidney transplant ible renal failure perioperatively and would benefit from candidates are therefore avoided. In this respect, kidney allo- KLTx. Preoperative renal dysfunction alone, or even the need cation differs substantially from that for recipients of heart and for preoperative , should not in itself be regarded liver transplants whose organs are distributed based on their as an indication for KLTx. Further work is required to help medical “status.” However, there are some dialysis patients determine the clinical features of those patients with ESLD who are indeed in “urgent need,” most typically because of whose renal failure is unlikely to improve after liver transplan- dialysis access failure or progressive neuropathy. Some OPOs tation and would therefore be appropriate candidates for KLTx. have developed variances that deal with this issue, although the majority have not. Current Controversy In 1991, UNOS undertook a feasibility study of a single Since its inception, the OPTN has lacked the authority to nationwide list for the sharing of cadaver kidneys (25). The enforce its policies since they have not been endorsed and study considered the proposal as a means to reduce the per- published by the executive branch of the federal government. ceived inequities associated with the wide regional variations All U.S. transplant programs and OPOs have complied with the in waiting times. The study concluded that a national single list OPTNЈs policies voluntarily. However, increasing concerns would create prolonged ischemic times for kidneys transported about potential violations and disparities in allocation of what across broad geographic distances. The consequent preserva- has been termed a “scarce national resource” focused attention J Am Soc Nephrol 10: 2237–2243, 1999 Cadaver Kidney Allocation 2241 on the relationship of the federal government to the private- hypertension and . The overall discard rate for cadav- sector OPTN. In 1998, the Secretary of DHHS submitted a eric organ recovery has increased to 12%, largely due to the proposed final rule that would provide this authority (28). This expanded criteria of potential medical suitability. Outcomes for rule contained principles for allocation to promote wider shar- recipients of organs from such expanded donors are negatively ing of organs and to reduce significant geographical differ- influenced with increased requirement for acute dialytic sup- ences in waiting times. UNOS and some other transplant port, decreased renal and graft survival, and increased organizations have objected to these proposed rules, stating patient mortality (21–23). that the Secretary may be attempting to set medical policy, Combined such as simultaneous kid- which should be the purview of the medical community. ney-pancreas for selected type I diabetic patients, or kidney- When UNOS and DHHS could not reach agreement on the liver or kidney-heart transplants is also presenting a growing proposed rule, Congress held public hearings in August 1998 ethical dilemma for the allocation of kidneys alone as these to examine the controversies (29). Several issues were outlined combined transplants reduce access and increase waiting times in the ensuing debate. One of those issues is allocation of for ESRD-only patients. The median waiting time for patients organs to the sickest patients first. This principle pertains awaiting a kidney alone is approximately three times longer principally to organs for which there is currently no satisfac- than for patients listed for a combined kidney-pancreas trans- tory alternative -sustaining treatments. Such is the case for plant in some OPOs. Changes in the distribution algorithm for liver and heart transplants. Some argue that if organs are liver transplants that favor the sickest ESLD patients are also allocated to the sickest first, smaller transplant programs with likely to increase the pressure for KLTx and therefore remove fewer very sick patients on their waiting lists would receive kidneys from distribution to the kidney waiting list. Also, as fewer donor organs than they currently do and might be forced the waiting time for kidney transplants inexorably lengthens, to close. Furthermore, if small, particularly specialized or the demand for kidneys for patients with failing dialysis access isolated programs closed, access to transplantation might be and other progressive medical problems that might qualify diminished for some candidates. At its most recent Board of them for emergency consideration for kidney transplantation Directors meeting in June 1999, UNOS approved a revision of increases. The nephrology community will be forced to devise liver allocation that requires that cadaver be offered first a manifestly equitable way to address these pressing needs to status 1 patients (the sickest liver transplant candidates) without unfairly disadvantaging the majority of stable dialysis within the region first, before they are distributed within the patients. recovering OPO. This revision does not apply to heart or Regional variations in cadaveric kidney waiting times are kidney allocation. dependent on many factors, including cadaveric organ avail- Another controversial issue concerns the influence of local ability, access to living donor organs, local competition for transplant programs to donation efforts and actual recovery in supply including ESRD prevalence, access to the transplant their local areas. Some claim that donation would suffer if local evaluation process, and the relative frequencies of donor-re- programs were to have diminished access to locally recovered cipient pool biologic incompatibilities that may affect status on organs or if transplant programs were to close. Public opinion a given match-run. Nonetheless, the existence of these varia- surveys on the subject of local use of organs have not clearly tions, whether they are real or apparent, suggests to some that demonstrated a preference on this issue. Based on the continu- the allocation of organs for transplantation in the United States ing controversy and lack of clear consensus, Congress subse- is not uniform for all citizens in need. Recently, the local use quently passed legislation as part of an appropriations bill that of cadaveric kidneys has decreased slightly and wider sharing delayed implementation of the proposed rule for 1 year, until has increased, but the appropriate relationship of local use to the fall of 1999. That legislation also mandated the Institute of wider sharing remains highly controversial both within the (IOM) to study the issue of organ allocation and transplant community and in political and regulatory bodies. produce a report by the summer of 1999. The IOM expert panel What can be done to address these problems? Obviously, we has been constituted and is expected to meet this timetable. In must continue to reduce organ wastage by improving short- the meantime, a number of states have reacted to the allocation and long-term graft survival rates both through basic science controversies by placing embargoes on cadaver organs recov- and clinical research efforts. Also, living donor kidney trans- ered within their state borders to restrict their use to transplant plantation is at present the least expensive and most successful programs within their borders. kind of organ transplant. The growing number of these types of transplants may be one of the most effective means currently Commentary available to deal with the increasing demands, but we must be Organ recovery has improved only modestly in recent years extremely careful to avoid excessive risk for living donors while the demand continues to increase. Despite short-term (31). Adults who have donated a kidney for transplantation improvements, long-term renal cadaveric allograft survival re- have been shown to have a life expectancy which actually mains finite with a current half-life of 10 to 11 years (30). exceeds that of the general population, which is likely due to Much of the increase in cadaveric organ donation has come the rigorous screening presently in practice which selects only through the expanded use of older donor organs (approximate- the healthiest candidates (32,33). Transplant centers must con- ly one-quarter are from donors over the age of 50 years) and tinue to exercise the same diligence, even as they seek to other organs with preexisting parenchymal disease such as increase the number of these operations. And finally, increased 2242 Journal of the American Society of Nephrology J Am Soc Nephrol 10: 2237–2243, 1999 recovery of cadaver organs suitable for transplantation is also 12. Light JA, Kowalski AE, Sasaki TM, Barhyte DY, Ritchie WO, critical. Every transplant program must feel a sense of urgency Gage F, Harviel JD: A rapid organ recovery program for non- to expand efforts in all three of these areas. heart-beating donors. Transplant Proc 29: 3553–3556, 1997 In the setting of the profound mismatch between supply and 13. Cho YW, Terasaki PI, Cecka JM: High kidney graft survival demand, difficult choices must be made. It is paramount that rates using non-heart-beating trauma donors. Transplant Proc 30: 3795–3796, 1998 such decisions continue to be made in an open and fair manner, 14. Butterworth PC, Taub N, Doughman TM, Horsburgh T, Veitch as the system of organ allocation and accessibility to transplan- PS, Bell PR, Nicholson ML: Are kidneys from non-heart-beating tation must always be open to scrutiny and careful analysis. donors second class organs? 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