Allocation of Deceased Donor Kidneys in São Paulo, Brazil: Effect of Human Leukocyte Antigen Compatibility on Graft Survival

In Brazil, organ transplantation has been regulated by a federal law since 1997. This law was created to guarantee equal access to treatment on a national scale. Deceased donor organ procurement and sharing are centralized and controlled by the Health Department of each state of the nation, following a regional allocation policy. In São Paulo, time on the waiting list was the main criterion adopted to allocate deceased donor kidneys up to January 1, 2002. After that, HLA mismatches (MM) were the main criterion. The aim of this study was to investigate the impact of HLA compatibility on graft survival among 3312 consecutive kidney recipients. The 2-year kidney graft survival rates were compared among recipients transplanted based on the waiting time policy and based on HLA MM. Better results were observed in the HLA MM group (78.1% vs 64.9%; P < .0001). Regarding kidney allocation based on HLA MM, recipients transplanted with 0 HLA-A, -B, or -DR MM showed significantly better 5-year survival rates than those with 1-2 or 3-4 or 5-6 HLA-A, -B, or -DR MM (70.36% vs 64.71% vs 58.07% vs 55.64%; P < .050). We concluded that HLA compatibility is a feasible criterion to allocate deceased donor kidneys in Brazil.     

HLA matching and the United Network for Organ Sharing Allocation System: impact of HLA matching on African-American recipients of cadaveric kidney transplants

BACKGROUND: A recent proposal supports the elimination of allocation points for human leukocyte antigen (HLA) mismatches (MM) in cadaveric kidney transplantation. The intent is to increase access for some racial groups that might be disadvantaged by the representation of race-specific HLA in a largely white donor pool. We report our experience from two transplant centers that serve a large African American (AA) patient population. METHODS: All cadaveric transplants into AA recipients from 1994 to 2000 (n=162) were included in a retrospective review. RESULTS: Superior graft survival was observed in AA recipients of 0 MM transplants. When induction therapy was used, the graft survival at 3 years for the human leukocyte antigen (HLA)-BDR MM grades given allocation points (0,1,2 MM) was 82% versus only 49% for BDR MM grades not given points (3,4 MM: =0.0022). CONCLUSIONS: Our collective experience demonstrates that AA patients having HLA-BDR MM grades given allocation points had better graft survival. Removing points for HLA from the national allocation system may result in significantly poorer outcome in AA kidney recipients.     

For the many: permitting deceased donor kidney transplantation across low‐titre blood group antibodies can reduce wait times for blood group B recipients,and improve the overall number of 000MM transplants ‐ a multicentre observational cohort study

Blood group O or B recipients wait longer for a kidney transplant. We studied the distribution of anti‐ABO blood group antibody titres in patients awaiting a kidney transplant, and modelled the effect of altering the UK National Kidney Allocation Scheme to allow for patients with ‘LOW’ titres (≤1:8, ≤3 dilutions) to receive a deceased donor ABOi (ddABOi) transplant. In a prospective study of 239 adult patients on the waiting list for a transplant in 2 UK centres, ABO‐antibody titres (anti‐A and anti‐B) were measured. Based on the proportions of ‘LOW’ anti‐A or anti‐B antibodies, four simulations were performed to model the current allocation rules compared with variations allowing ddABOi allocation under various conditions of blood group, HLA matching, and waiting time. The simulations permitting ddABOi resulted in more blood group B recipients being transplanted, with median waiting time reduced for this group of recipients, and more equitable waiting times across blood groups. Additionally, permitting ddABOi resulted in greater numbers of 000MM allocations overall in compatible transplants under modelled conditions. Changing allocation in the UK to permit ddABOi in patients with ‘LOW’ titres would not change the total number of transplants, but redistributes allocation more equitably amongst blood groups, altering waiting times accordingly.     

The PROCARE consortium: Toward an improved allocation strategy for kidney allografts

Kidney transplantation is the best treatment option for patients with end-stage renal failure. At present, approximately 800 Dutch patients are registered on the active waiting list of Eurotransplant. The waiting time in the Netherlands for a kidney from a deceased donor is on average between 3 and 4 years. During this period, patients are fully dependent on dialysis, which replaces only partly the renal function, whereas the quality of life is limited. Mortality among patients on the waiting list is high. In order to increase the number of kidney donors, several initiatives have been undertaken by the Dutch Kidney Foundation including national calls for donor registration and providing information on organ donation and kidney transplantation. The aim of the national PROCARE consortium is to develop improved matching algorithms that will lead to a prolonged survival of transplanted donor kidneys and a reduced HLA immunization. The latter will positively affect the waiting time for a retransplantation.The present algorithm for allocation is among others based on matching for HLA antigens, which were originally defined by antibodies using serological typing techniques. However, several studies suggest that this algorithm needs adaptation and that other immune parameters which are currently not included may assist in improving graft survival rates. We will employ a multicenter-based evaluation on 5429 patients transplanted between 1995 and 2005 in the Netherlands. The association between key clinical endpoints and selected laboratory defined parameters will be examined, including Luminex-defined HLA antibody specificities, T and B cell epitopes recognized on the mismatched HLA antigens, non-HLA antibodies, and also polymorphisms in complement and Fc receptors functionally associated with effector functions of anti-graft antibodies. From these data, key parameters determining the success of kidney transplantation will be identified which will lead to the identification of additional parameters to be included in future matching algorithms aiming to extend survival of transplanted kidneys and to diminish HLA immunization. Computer simulation studies will reveal the number of patients having a direct benefit from improved matching, the effect on shortening of the waiting list, and the decrease in waiting time.     

HLA配型与肾移植术后早期急性排斥反应的关系

目的 研究ＨＬＡ配型与尸体肾移植术后早期急性排斥反应的关系。方法 将２６２例尸体肾移植受者按ＨＬＡ配型的误配率（ＭＭ）进行分组,统计各组术后１～２个月内急性排斥反应的发生次数。结果 当ＭＭ〉３时,若接受的器官ＨＬＡ抗原／基因为可接受性,术后急性排斥反应的发生率为１６．４％;若供体器官ＨＬＡ抗原／基因具免疫原性,则急性排斥反应的发生率为３３．１％,两者比较,Ｐ〈０．０５。结论 供受者间ＨＬＡ配型越好     

Strategies for compensating for the declining numbers of cadaver donor kidney transplants.

BACKGROUND: The living-donor and dual kidney transplantation programmes were initiated in the transplantation centre of Münster (TCM) as two approaches to compensate for the declining numbers of cadaver donor kidney transplants after the implementation of the new Eurotransplant Kidney Allocation System (ETKAS). We analysed the outcome of cadaver, living-donor and dual kidney transplantation and their effects on the waiting list in the TCM. METHODS: Between January 1990 and December 2000, 1184 kidney transplants were performed in the TCM. They were subdivided into cadaver, living-donor and dual kidney transplants and retrospectively analysed in terms of the number of kidney transplants performed, waiting time and waiting coefficient. In addition four representative groups were formed to reflect donor origin (I: cadaver kidney transplants allocated by the old ETKAS, n = 180; II: cadaver kidney transplants allocated by the new ETKAS, n = 139; III: living-donor kidney transplantation, n = 59; IV: dual kidney transplantation, n = 31) and compared according to graft function (initial diuresis, creatinine, 3-year graft function), patient survival and median waiting time. RESULTS: After the implementation of the new ETKAS, the number of cadaver donor kidney transplants at the TCM almost halved, but the proportion of living-donor kidney transplantations increased significantly by 12.8% and of dual kidney transplantations by 8.5%. Patients who had received kidneys from cadaver donors allocated by the new ETKAS (group II) had a better survival rate, short- and long-term function but a longer waiting time than in group I (old ETKAS). Patients with dual kidney transplants (group IV) showed the lowest survival and short-term function rate, but had long-term function equivalent to that of cadaver kidney transplants (groups I and II). Patients who had received kidneys from living donors (group III) had the best survival, and short- and long-term function rate as well as the shortest mean waiting time. CONCLUSIONS: Living-donor and dual kidney transplantation proved to be functionally equivalent alternatives and successful strategies for compensating the declining numbers of cadaver donor kidney transplants.     

Application of Prastat ELISA in the determination of anti‐HLA specificity for immunized patients awaiting kidney transplant: five years' experience

Abstract Three hundred sixty‐five patients who underwent cadaver donor kidney transplantation between 1993 and 1998 were divided into four groups: 40 immunized patients with at least one peak panel‐reactive antibody (PRA) value more than 50%, 11 hyperimmunized patients with more than three peak PRA values over 50%, 10 retransplanted patients and 304 control patients. Before transplantation, we ascertained the antibody specificities against individual HLA antigens (Prastat Sangstat ELISA method for HLA typing of first donor, husbands of multiparous women and potential donors against whom candidates gave positive cross‐matches); thus, patients underwent transplantation excluding the presence of the HLA antigens previously detected and looking for high HLA (class I and II) compatibility. Actuarial graft survival after 12 months was satisfactory in all groups: 87 % immunized, 81% hyperimmunized and 80% re‐transplanted vs 92% controls. Renal function at the end of the first year was similar and the number of rejection episodes in the first 3 months did not significantly differ.     

The effect of first cadaver renal transplant HLA-A, B match on sensitization levels and retransplant rates following graft failure

Data were collected retrospectively on all 449 first-transplant cadaver renal allograft recipients transplanted at four centers between 1/1/78 an 12/31/82 who had graft failure by 1/1/85. A total of 383 of these patients had information available regarding subsequent disposition. Of these, 182 (47.5%) were placed on an active waiting list for retransplantation. There were no associations found between placement on a waiting list and the following variables: panel reactive antibody (PRA) prior to first transplant or subsequent to graft failure, recipient age at first transplant or at the time of graft failure, recipient race, PRA after first graft loss, or HLA-A, B match of the first transplant. When stratified by level of HLA-A, B match as poor (0-1 antigen, n = 150) or good (2-4 antigens, n = 233) the poorly matched recipients as a group had a significantly lower mean PRA prior to first transplant (9.4 +/- 1.6 vs. 15.5 +/- 1.7, P less than 0.01), but a significantly higher PRA within the first year following graft failure (48.1 +/- 4.8 vs. 36.2 +/- 3.2, P less than 0.04). In addition, the poorly matched (vs. well-matched) group had a significantly higher mean increase in PRA following graft failure (45.1 +/- 4.4 vs. 33.7 +/- 3.5), and a significantly higher percentage of patients with PRA level greater than or equal to 60% within a year after graft failure (40% vs. 25%). Of the 182 patients who were placed on a waiting list, 113 (62.1%) were regrafted. As a group, regrafted patients had a significantly lower PRA within the first year following graft failure compared with the group not regrafted (33.6 +/- 3.9 vs. 54.0 +/- 5.0, P less than 0.002). Patients with a good first transplant HLA match had a higher overall regraft rate compared with those with a poor match (70.0% vs. 50.0%, P less than 0.01). Likewise, the percentage of well-matched patients regrafted within two years of first graft failure was significantly higher (55.5% vs. 32.5%, P less than 0.02). By multivariate analysis using the Cox proportional hazard model with 13 separate variables and considering all patients, the relative risk (RR) of not being regrafted was significantly (P less than 0.012) associated with poor HLA-A, B matching of the first transplant (RR = 1.7).(ABSTRACT TRUNCATED AT 400 WORDS)     

Simultaneous pancreas-kidney transplantation is improved by living kidney donation program

BACKGROUND: Shortage of suitable donors and current graft allocation priorities reduce the number of cadaveric kidneys available to diabetic recipients. The concurrent excess of solitary cadaveric pancreata and the excellent results of living kidney transplantation make simultaneous cadaveric pancreas-living kidney transplantation (SPLKTx) an attractive alternative to simultaneous pancreas-kidney transplantation (SPKTx). METHODS: Between June 2001 and June 2003, 80 recipients were enrolled in the SPKTx waiting list. Each recipient's family was counseled about living kidney donation (LKD). Twenty-nine (36.2%) candidates were evaluated for LKD and 8 (27.6%) were disqualified. The remaining 21 candidates were scheduled for LKD and 18 actually donated. RESULTS: Thanks to LKD 18 additional recipients were transplanted, thus expanding the donor pool from 33 to 51 (P =.004). The median waiting time for SPLKTx was 14 days as compared with 95 days for SPKTx (P =.006). Without LKD the median waiting time for SPKTx would have been 198 days (P =.02). Similarly, 1 year after the enrollment on the waiting list 60% of recipients had been transplanted, while without LKD only 42% would had been grafted (P =.01). Two-year recipient survival rate was 100% for SPLKTx compared with 96.9% for SPKTx. Equivalent figures for kidney and pancreas were 80.0% and 84.0% for SPLKTx compared with 96.9% and 96.9% for SPKTx. CONCLUSIONS: LKD expanded the kidney donor pool, reduced the waiting time of recipients listed for a totally cadaveric procedure, and increased their chance to get a timely graft. One-year outcome of SPLKTx equaled that of SPKTx.     

Pediatric cadaver kidney transplants into adults

During a 5-year period 77 adults received single kidney cadaver transplants from donors 16 months to 16 years old. Cyclosporin immunosuppression was not used. Three recipients had ischemic ureteral complications, 1 of which resulted in allograft loss. Of the kidney grafts 34 were from donors 8 years old or younger, and comparison of renal function was made with the 43 adult recipients of cadaver kidneys from older children. The mean 1-month serum creatinine nadir was significantly higher in the recipients of kidneys from the younger children (2.6 plus or minus 1.6 versus 1.9 plus or minus 0.8 mg./per dl.). There were no statistically significant differences in 1-week dialysis requirement, 1-month kidney graft function or actuarial kidney graft survivals and serum creatinine levels at 3, 6, 12 and 24 months after grafting. Cadaver kidneys from young donors can be transplanted successfully into adults.     

Long term results of living donor kidney transplantation: graft and patient survival

Donor kidney transplantation's graft and patient survivals are better than cadaver donor's. In Spain, living donor kidney transplantation hardly accounts for 1% of transplant activity in comparison to 60% in United States. Accordingly to bibliography, the experience of the Renal Transplant Unit of the Hospital Clinic de Barcelona has demonstrated better graft and receptor survival for living donor recipients. The analysis of 184 living donor kidney transplants and 1678 cadaver donor transplants performed between 1978 and 2002 showed that graft survival was higher in the group of living donors (p < 0.01). At the same time, graft survival was clearly better in receptors of HLA haploidentical grafts (n=142) (p < 0.05). The introduction of new and better immunosuppressive drugs, as well as better diagnostic and therapeutic management of acute rejection, prophylaxis for infections, and control of complications have contributed to better results. The absence of acute rejection between 1978 and 1983 was 45.1%, between 1984 and 1998 was 57.3% and 84.7% between 1999 and 2003. In conclusion, these results demonstrate better graft and patient survival for living donor kidney transplants in comparison with cadaver donor receptors. Altogether with the low risk involved for donors should incentivate authorities, professionals, and patients to promote these therapeutic option by means of adequate information and wider diffusion. Living donor kidney transplantation should contribute together with cadaver kidney transplantation to lessen our long waiting lists, because they are not excluding options.     

交叉反应组配型在高致敏患者肾移植中的应用

目的 探讨交叉反应组(CBEG)配型在高致敏患者肾移植中的临床意义。方法 动态监测肾移植受者体内群体反应性抗体(PRA)的水平及其特异性，按照CREG配型原则选择最匹配的供者。结果 60例受者术前PRA超过11％，均有单纯性或混合性升高；按照CREG配型，0～1个抗原错配、2个抗原错配、3～4个抗原错配者术后肌酐恢复正常的时间平均为6．5d、7．0d、12．7d，发生肾功能恢复延迟的例数分别为0、7例、3例，各组间的差异具有显著性(P＜0．05)。结论 高致敏受者在肾移植时采用CREG配型，可避开受者预存的HLA抗体特异性所对应的抗原，对于提高肾移植人／肾存活率具有重要意义。     

Pancreas after kidney transplants

BACKGROUND: For certain uremic diabetic patients, a sequential transplant of a kidney (usually from a living donor) followed by a cadaver pancreas has become an attractive alternative to a simultaneous transplant of both organs. The purpose of this study was to compare outcomes with simultaneous pancreas-kidney (SPK) versus pancreas after kidney (PAK) transplants to determine advantages and disadvantages of the two procedures. METHODS: Between January 1, 1994, and June 30, 2000, we performed 398 cadaver pancreas transplants at our center. Of these, 193 were SPK transplants and 205 were PAK transplants. We compared these two groups with regard to several endpoints, including patient and graft survival rates, surgical complications, acute rejection rates, waiting times, length of hospital stay, and quality of life. RESULTS: Overall, surgical complications were more common for SPK recipients. The total relaparotomy rate was 25.9% for SPK recipients versus 15.1% for PAK recipients (P = 0.006). Leaks, intraabdominal infections, and wound infections were all significantly more common in SPK recipients (P = 0.009, P = 0.05, and P = 0.01, respectively, versus PAK recipients). Short-term pancreas graft survival rates were similar between the two groups: at 1 year posttransplant, 78.0% for SPK recipients and 77.9% for PAK recipients (P = not significant). By 3 years, however, pancreas graft survival differed between the two groups (74.1% for SPK and 61.7% for PAK recipients), although this did not quite reach statistical significance (P = 0.15). This difference in graft survival seemed to be due to increased immunologic losses for PAK recipients: at 3 years posttransplant, the incidence of immunologic graft loss was 16.2% for PAK versus 5.2% for SPK recipients (P = 0.01). Kidney graft survival rates were, however, better for PAK recipients. At 3 years after their kidney transplant, kidney graft survival rates were 83.6% for SPK and 94.6% for PAK recipients (P = 0.001). The mean waiting time to receive the pancreas transplant was 244 days for SPK and 167 days for PAK recipients (P = 0.001). CONCLUSIONS: PAK transplants are a viable option for uremic diabetics. While long-term pancreas graft results are slightly inferior to SPK transplants, the advantages of PAK transplants include the possibility of a preemptive living donor kidney transplant, better long-term kidney graft survival, significantly decreased waiting times, and decreased surgical complication rates. Use of a living donor for the kidney transplant expands the donor pool. Improvements in immunosuppressive regimens will hopefully eliminate some of the difference in long-term pancreas graft survival between SPK and PAK transplants.     

Preemptive kidney transplantation: the advantage and the advantaged

It remains unclear whether preemptive transplantation is beneficial, and if so, who benefits. A total of 38,836 first, kidney-only transplants between 1995 and 1998 were retrospectively studied. A surprising 39% of preemptive transplants were from cadaver donors, and the proportions of cadaver donor transplants that were preemptive changed little, from 7.3% in 1995 to 7.7% in 1998. Preemptive transplants using cadaver donors were more likely among recipients aged 0 to 17 yr versus 18 to 29 yr (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.94 to 3.17), white versus black (OR, 2.33; 95% CI, 2.03 to 2.68), able to work versus unable to work (OR, 1.42; 95% CI, 1.26 to 1.61), covered by private insurance versus Medicare (OR, 4.77; 95% CI, 4.26 to 5.32), or recipients with a college degree versus no college degree (OR, 1.34; 95% CI, 1.17 to 1.54). Preemptive transplants were less likely for Hispanics versus non-Hispanics (OR, 0.57; 95% CI, 0.50 to 0.67), patients with type 2 versus type 1 diabetes (OR, 0.76; 95% CI, 0.61 to 0.96), and for 2 to 5 HLA mismatches compared with 0 HLA mismatches (OR range, 0.77 to 0.82). In adjusted Cox proportional hazards analysis, the relative risk of graft failure for preemptive transplantation was 0.75 (0.67 to 0.84) among 25,758 cadaver donor transplants and 0.73 (0.64 to 0.83) among 13,078 living donor transplants, compared with patients who received a transplant after already being on dialysis. Preemptive transplantation was associated with a reduced risk of death: 0.84 (0.72 to 0.99) for cadaver donor transplants and 0.69 (0.56 to 0.85) for living donor transplants. Thus, preemptive transplantation, which is associated with improved patient and graft survival, is less common among racial minorities, those who have less education, and those who must rely on Medicare for primary payment. Alterations in the payment system, emphasis on early referral, and changes in cadaver kidney allocation could increase the number of patients who benefit from preemptive transplantation.     

Recipient race does not influence waiting time for a cadaveric renal transplant--one organ procurement organization's experience

There was no statistical significance to the differences in waiting time for cadaveric renal transplant by race. Whether for first transplant or second or greater, any differences in waiting time could not be accounted for by the recipient's race. CAUC made up 58% of the waiting list, 65% of the recipients, and 87% of the donors. The corresponding numbers for AA are: 38%, 29%, and 10%, respectively. More regional serum-sharing trays may be needed in order to expose recipients with high PRA to as many donors as possible in order to lessen their waiting time. It should be noted that fewer HLA mismatches occurred when donor and recipient race were identical. In light of this data, more study is needed to determine the relationship between donor and recipient race, corresponding HLA mismatches, and graft survival. If antigen-matching is found to increase graft survival, then an increase in minority donations will be required. Until that time, under the current allocation system and with the predominance of Caucasian donors, it is likely that Afro-Americans will continue to receive kidneys that have more HLA antigen mismatches than if Afro-Americans donated in numbers equivalent to their percentage of the waiting list.     

Critical evaluation of the amino acid triplet-epitope matching concept in cadaver kidney transplantation

BACKGROUND: A computer-based approach for determining human leukocyte antigen (HLA) compatibility between kidney donors and recipients on the basis of differences of amino acid sequences as motifs for immunogenic epitopes was proposed by Duquesnoy et al. The HLAMatchmaker algorithm focuses on HLA class I polymorphisms of serologically defined antigens encoded by the HLA-A and -B loci. HLA phenotypic mismatches that represent only a few mismatches at the amino acid triplet level are held to be not or only mildly immunogenic. This approach was proposed as being especially suitable for the allocation of donor kidneys to highly sensitized patients. METHODS: We reexamined this attractive concept using the data of the Collaborative Transplant Study. Intra- and interlocus comparisons for HLA-A and -B were performed according to the original HLAMatchmaker algorithm. To exclude the influence of HLA-DR, only transplants with no HLA-DR mismatch were considered. Patients who had one HLA-A and one HLA-B antigen mismatch were separated into subgroups, depending on the number of triplet mismatches as calculated by the HLAMatchmaker software. Separate analyses were performed for first transplants, retransplants, and patients with a panel-reactive antibody activity of 50% or more. A total of 16,997 white patients matched for HLA-DR who received a cadaver kidney transplant between 1991 and 2001 formed the basis of this analysis. RESULTS: Application of the HLAMatchmaker method could not be shown to result in any statistically significant effect on graft survival. CONCLUSIONS: The HLAMatchmaker concept is theoretically attractive; however, it could not be shown to yield useful results in this analysis. Serologic HLA typing appears to provide an insufficient basis for applying epitope matching in clinical kidney transplantation.     

Simultaneous cadaver pancreas living-donor kidney transplantation: a new approach for the type 1 diabetic uremic patient

OBJECTIVE: To review the authors' experience with a new approach for type I diabetic uremic patients: simultaneous cadaver-donor pancreas and living-donor kidney transplant (SPLK). SUMMARY BACKGROUND DATA: Simultaneous cadaver kidney and pancreas transplantation (SPK) and living-donor kidney transplantation alone followed by a solitary cadaver-donor pancreas transplant (PAK) have been the transplant options for type I diabetic uremic patients. SPK pancreas graft survival has historically exceeded that of solitary pancreas transplantation. Recent improvement in solitary pancreas transplant survival rates has narrowed the advantage seen with SPK. PAK, however, requires sequential transplant operations. In contrast to PAK and SPK, SPLK is a single operation that offers the potential benefits of living kidney donation: shorter waiting time, expansion of the organ donor pool, and improved short-term and long-term renal graft function. METHODS: Between May 1998 and September 1999, the authors performed 30 SPLK procedures, coordinating the cadaver pancreas transplant with simultaneous transplantation of a laparoscopically removed living-donor kidney. Of the 30 SPLKs, 28 (93%) were portally and enterically drained. During the same period, the authors also performed 19 primary SPK and 17 primary PAK transplants. RESULTS: One-year pancreas, kidney, and patient survival rates were 88%, 95%, and 95% for SPLK recipients. One-year pancreas graft survival rates in SPK and PAK recipients were 84% and 71%. Of 30 SPLK transplants, 29 (97%) had immediate renal graft function, whereas 79% of SPK kidneys had immediate function. Reoperative rates, early readmission to the hospital, and initial length of stay were similar between SPLK and SPK recipients. SPLK recipients had a shorter wait time for transplantation. CONCLUSIONS: Early pancreas, kidney, and patient survival rates after SPLK are similar to those for SPK. Waiting time was significantly shortened. SPLK recipients had lower rates of delayed renal graft function than SPK recipients. Combining cadaver pancreas transplantation with living-donor kidney transplantation does not harm renal graft outcome. Given the advantages of living-donor kidney transplant, SPLK should be considered for all uremic type I diabetic patients with living donors.     

Effect of implementing anti-HLA antibody detection by Luminex in the kidney transplant program in Chile

The development of new highly sensitive, specific technologies to detect HLA antibodies has allowed a better definition of the profile of non-permitted antigens for patients awaiting kidney transplantation. The use of calculated or virtual panel reactive antibodies (CPRA or vPRA) seeks to improve the prediction of positive crossmatches (XM), but increases the proportion of sensitized patients on the waiting list. In 2008-2009, we implemented detection of antibodies using Luminex technology and applied vPRA since 2009. The objective of this study was to evaluate the impact of these innovations in defecting patient sensitization on kidney transplant waiting lists for deceased donors and among transplanted patients. We analyzed the waiting list for 2007 through 2009 and the first semester of 2010, including the patients transplanted in these periods and the XM with deceased donors. We observed an increase in the mean peak PRA of transplanted patients from 7.2% in 2007 to 17.1% in 2010 (P = .001), and in the proportion of patients transplanted with a peak PRA > 50% from 2.8% in 2007 to 15.7% in 2010 (P = .0001), with no increase in the proportion of this population on the waiting lists. There was a concurrent decrease in positive XM among patients with a peak PRA > 50%. The use of vPRA and Luminex permitted a greater number of transplants of patients with peak PRA > 50% and was a good predictor of a positive XM.     

The effect of HLA mismatch on highly sensitized renal allograft recipients

Paramesh AS, Zhang R, Baber J, Yau CL, Slakey DP, Killackey MT, Ren Q, Sullivan K, Heneghan J, Florman SS. The effect of HLA mismatch on highly sensitized renal allograft recipients.
Clin Transplant 2010: 24: E247–E252. © 2010 John Wiley & Sons A/S. Abstract: Introduction: We examined the effects of increasing human leukocyte antigen (HLA) mismatches (MM) on long‐term graft outcomes in patients transplanted with a panel reactive antibody (PRA) >80% over a 10‐yr period. Methods: A total of 142 recipients were divided into three groups based on the number of HLA MM with their allograft (0–2, 3–4 and 5–6 MM; Groups I, II and III). All patients received the same immunosuppression protocol. Results: The higher MM groups had a higher incidence of rejection (4.4% vs. 11.4% vs. 31.3%, p < 0.01). A multivariate analysis showed that rejection was the only significant variable affecting graft loss (OR = 7.45, p = 0.01). There was a trend toward more CMV infection and worse graft function with higher MM. Kaplan–Meier five‐yr graft survival estimates were 100% vs. 81% vs. 74% for Groups I, II and III, respectively (p = 0.14). Conclusions: In patients with PRA levels >80%, a higher HLA MM is associated with higher incidence of acute rejection. Acute rejection was the only significant variable affecting graft loss. We found a trend toward more CMV infections and worse graft outcomes with higher MM. Closer HLA matching and immunologic monitoring needs to be considered to improve graft outcomes among sensitized recipients.     

An evaluation of HLA cross-reactive group matching on graft survival in deceased donor kidney recipients

Since September 20, 1999, our organ procurement organization (OPO) serving an ethnically diverse local distribution area has allocated kidneys using a cross-reactive group (CREG)-based variance. This variance awards 7 points for 0-CREG,0-DR mismatches and 6 points for 0-A,B mismatches in addition to points given for waiting time (3) and panel-reactive antibodies (PRA) > or = 80% (3). Previously, we have shown that awarding points for 0-CREG,0-DR mismatches in kidney allocation improves the access to HLA-matched transplants for racial groups, especially for the black race. In this study, we evaluated if there are outcome benefits as well. One- and 3-year uncensored graft survival data and analyses for the influence of HLA mismatching on graft outcome in black and nonblack recipients were provided by Scientific Registry of Transplant Recipients (SRTR). Overall, 1-year graft survival was 87.4% and not significantly different for blacks (86.1%, n = 467) vs nonblacks (88.8%, n = 730); 3-year graft survival was 74.6% and significantly lower P = .0001 for blacks (68.5%, n = 480) vs nonblacks (78.4%, n = 765). No significant advantage was observed for either the black or nonblack recipients in any of the HLA-mismatched categories, including the 0-CREG,0-DR mismatch group. An HLA matching effect also was not seen when data were stratified for patients nonsensitized (PRA < or = 10%) and sensitized (PRA > 10%) at the time of transplantation, except for the improved graft survival in sensitized nonblack recipients of 0- A,B,DR-mismatched grafts. Of the patients who lost their grafts and returned to the waiting list for retransplantation, the 0-A,B,DR mismatched were the least sensitized group (6%, n = 16), and there was a trend for less sensitization in the 0-CREG,0-DR-mismatched group (33%, n = 9), compared to those with other HLA mismatches (68%, n = 137). Thus, based on 1-year and 3-year follow-up data, there are no apparent graft outcome benefits for either CREG matching or conventional HLA matching in our service area, except for sensitized nonblack recipients receiving 0-A,B,DR-mismatched grafts. Such benefits may become more apparent with longer follow-up.