New cost-effective human leukocyte antigen testing algorithm for screening of human leukocyte antigen-matched related donor in thalassemia major patient pretransplant workup: A single-center study from resource-constrained settings

Introduction: India has a huge disease burden of thalassemia major with an estimated 40 million carriers and over a million thalassemia major patients. Very few patients are optimally treated, and the standard of care “hematopoietic stem cell transplant” (HSCT) is out of reach for most patients and their families. The cost of HSCT is significant, and a substantial proportion of it goes to human leukocyte antigen (HLA) testing of family members (HLA screening) in hope of getting a matched related donor (MRD) for HSCT. The aim of this study was to establish that a new proposed testing algorithm of HLA typing would be more cost-effective as compared to the conventional HLA screening within MRD families for possible HSCT. Material and Methods: Buccal swab samples of 177 thalassemia patients and their prospective family donors (232) were collected. Using a new HLA testing algorithm, samples were tested for HLA typing in a sequential manner (first HLA-B, then HLA-A, and finally HLA-DR) using the sequence-specific oligonucleotide probe method on the Luminex platform. Results: The new sequential HLA-A, HLA-B, and HLA-DRB1 testing algorithm showed a 49.1% reduction in cost compared to the conventional HLA testing algorithm. Furthermore, 40 patients (22.59%) were found to have HLA-MRD within the family among other samples that were tested. Conclusion: The new HLA testing algorithm proposed in the present study for identifying MRD for HSCT resulted in a substantial reduction in the cost of HSCT workup.

Pathological analysis of time-zero renal biopsy in donor kidney / 中华器官移植杂志

Objective To summarize the pathological survey of time-zero renal biopsy (T0-RBx ) . Methods The material qualities and pathological features were analyzed retrospectively for T 0-RBx (n=176) between March 2008 and May 2016 .According to the source of donor kidney ,T0-RBx specimens were divided into living donors (LD) group (n=137) and Deceased donation (DD) group (n=39) .Furthermore , the DD group was divided into cerebral hemorrhage group (n= 10) and brain trauma group (n= 29) according to the causes of death .The inter-group differences of pathological characteristics and the effects of abnormal pathological lesions on allograft function were observed .Results All T0-RBx specimens contained cortical kidney tissue .The average microscopic length of renal tissue was (0 .39 ± 0 .23) cm and the median glomerular number 11 . The abnormal pathological lesions included glomerulosclerosis (GS ,30 .7 ％ ) , segmental glomerulosclerosis (1 .1 ％ ) ,mesangial increase (MI ,19 .3 ％ ) ,tubular atrophy (TA ,35 .2 ％ ) , acute tubular necrosis (ATN ,9 .1 ％ ) ,vacuolar degeneration of tubular epithelium (27 .3 ％ ) ,losses in tubule epithelial brush border (97 .7 ％ ) , protein cast (25 ％ ) , interstitial fibrosis (IF ,34 .1 ％ ) , inflammation (I ,42 .6 ％ ) ,arteriolar hyalinosis (AH) (26 .1 ％ ) and vascular fibrous intimal thickening (CV ,23 .3 ％ ) .Among them ,23 .9 ％ ,1 .1 ％ ,0 .55 ％ and 0 .55 ％ cases were diagnosed as IgA nephropathy ,immune complex associated with glomerular disease and focal segmental glomerulosclerosis diabetic nephropathy respectively .And the reminders were of ischemic injury .The incidence rates of TA ,IF and I were lower in DD group than those in LD group ( P< 0 .05 ) . However , ATN and vacuolar degeneration of tubular epithelium were higher (P<0 .001) .The incidence of GS was significantly higher in cerebral hemorrhage group than that in brain trauma group (P<0 .01) .No statistical difference existed in other lesions or disease constitution among the groups (P>0 .05) .Further analysis showed GS was related with allograft function at 6/12 months post-transplantation in both LD and DD groups (P<0 .05) .IF and AH were also related to short-term renal function of recipients post-transplantation in LD and DD groups (P>0 .05) .Conclusions T0-RBx may detect the abnormal lesions of donor kidney .Some differences exist in types and degree of abnormal lesions among different donor kidneys .LD group has a higher risk for chronic histological injury such as TA and IF while DD group is more susceptible to acute renal tubular interstitial injury .Thus it is valuable for predicting allograft function post-transplantation .Material quality is essential for ensuring the reliability of T 0-RBx .

Nefrectomía robótica del donante vivo para trasplante: primer caso en latinoamérica / Living robotic donor nephrectomy: the first case in latin america

Introduction: Living donor nephrectomy is the best alternative of treatment for patients with chronic renal disease. Even though open surgery remains the gold standard for donor nephrectomy, laparoscopic surgery has become a feasible alternative in referral centers. To minimize the long learning curve associated with this procedure, some centers have introduced robotic donor nephrectomy as a surgical option. Aim: To present the first robotic-assisted laparoscopic donor nephrectomy in Latin America. Clinical case: The donor is a 50 years old male, living-related to the recipient by affinity (husband/wife). The recipient is a 54 years old female with history of end-stage renal disease waiting to initiate dialysis program. A left transperitoneal robotic-assisted laparoscopic nephrectomy employing the da Vinci Si® (Intuitive Surgical, Sunnyvale CA.) is performed. Mean operative time was 188 minutes with an estimated blood loss of 300 ml. Mean ischemia time was 6 minutes. The graft presented immediate function. Both patients were discharged at 72 h. Conclusion: Living donor robotic-assisted laparoscopic nephrectomy is a safe and viable procedure. Larger series are needed to establish its role.

Introducción: La donación renal en pacientes vivos relacionados es la mejor alternativa de tratamiento para pacientes con insuficiencia renal crónica. La cirugía abierta es el procedimiento de elección; sin embargo, la nefrectomía laparoscópica se ha convertido en una opción viable en centros con experiencia. Con el propósito de disminuír los tiempos de la curva de aprendizaje, algunos centros han introducido la nefrectomía robótica del donante vivo como una opción quirúrgica. Objetivo: Presentar la primera nefrectomía robótica del donante vivo realizada en Latinoamérica. Caso clínico: Paciente de 50 años, esposo, donante vivo relacionado, por afinidad (esposo-esposa). La receptora tiene 54 años con antecedente de insuficiencia renal crónica terminal en espera de ingreso a programa de hemodiálisis. Se realizó nefrectomía robótica izquierda del donante utilizando el sistema robótico da Vinci Si® (Intuitive Surgical, Sunnyvale CA.) mediante abordaje transperitoneal. El tiempo quirúrgico total fue de 188 min, con un sangrado estimado de 300 ml., y un tiempo de isquemia de 6 min. El injerto presentó inicio inmediato de la función. Ambos pacientes fueron dados de alta a las 72 h. Conclusión: La nefrectomía robótica del donante vivo para trasplante es una alternativa segura y factible. Comunicaciones con series con mayor número de pacientes, son necesarias para establecer su definitivo rol.

Clinical analysis on the relationship between the donor resource and the result of living related donor kidney transplantation / 复旦学报（医学版）

Objective To analyze the impact of allograft category on the result of living related donor kidney transplantation (LRKT)and to evaluate the predominant donors. Methods A retrospective analysis of 104 recipients receiving LRKT from Apr. 2004 to Mar. 2008 was performed. Based on donor resource, all the recipient-donor pairs were divided into four groups: spousal donation group,parental donation group, sibling donation group and cousinly donation group. The observational parameters were selected for analysis, such as average post-transplant hospitalization dates, time for serum creatinine (Scr) back to normal level, Scr levels of every observational time point, incidence of major complications (infection, rejection, DGF) and recipient/graft survival rate. Results Recipient/graft survival rate of sibling donation group seemed higher. Recipients of sibling donation group seemed to have fewer post-transplant hospitalization dates, but higher rates of infection, while those of parental donation group seemed to have higher rates of rejection. Rates of rejection and infection of spousal donation group were lower than supposed. There was no statistically significant difference in time for Scr back to normal level and Set levels of every observational time point among these four groups. Conclusions The result of sibling donor renal transplantation is better, while short-term outcome of spouse donor renal transplantation is ideal, which is similar with parent or cousin donor renal transplantation. Except for human leukocyte antigen, aspects such as quality of donor kidney, predominance during operation and self-administration post-transplant are also the guarantee for the success.

Analysis of the safety of elderly living related kidney donors / 中华泌尿外科杂志

Objective To explore the safety of the elderly donors in living related donor kidney transplantation. Methods Forty-five elderly donors (51 - 78 years,study group) who underwent ne-phrectomy for living related donor kidney transplantation from April 1993 to December 2007 were retrospectively investigated. Clinical data including serum creatinine (SCr), glomerular filtration rate (GFR) in pre-and post-operation, operation complications and hospital stay time were analyzed and compared with the control group(62 cases, the donors age were younger than 50 years). Results The operations of all living donors were successful. The SCr and GFR in pre-operation were (82.16 ± 10.86)μmol/L, (85. 82±6.26)ml/min(study group)and (78. 66±10. 41)μmol/L, (88. 74±9. 44) ml/min (control group) respectively. There were no significant differences in SCr and GFR between the groups at different time points (P>0. 05). The average hospitalization time was 9 days in study group and 8 days in control group. There were no severe perioperative complications and no renal function failure was found in long-term following-up in study group. Conclusions Age is not the absolute contraindication of donor for living related donor kidney transplantation. The preoperative evaluation and careful operation can ensure the safety of elderly donors.

Trasplante renal: dilemas y bioética / Kidney transplantation: bioethics and dilemmas

El progreso de la ciencia y en especial el de los trasplantes de riñón amerita muchas reflexiones éticas, pues no todos los dilemas que se presentan se han solucionado y algunos no han sido tomados como tales. Los donantes vivos pueden ser sujetos a coacción, pues adquieren un compromiso con la familia, la sociedad y el equipo de salud para donar su riñón. Muchos en realidad no lo quieren hacer, aunque en los libros aparezca la donación como el mayor acto de amor y solidaridad. No todos los hijos quieren a sus padres y viceversa, ni todos los hermanos se quieren entre sí. Son muy importantes los conceptos de solidaridad y amor, que no suelen aparecer de manera espontánea en la vida de los individuos. Amor es un arte que implica dar pero de una forma madura. ¿Tendrán todos los donantes esta capacidad de dar? Si no la tienen es probable que estén siendo víctima de una coacción. Como existen tantos dilemas éticos con el trasplante de riñón, la bioética ayuda a dar respuesta a tantas inquietudes para poder colaborar con más efectividad a los involucrados en él.

Scientific breakthroughs, especially kidney transplantation, deserve serious ethical reflections for not all dilemmas that arise have been addressed and some have not been contemplated as such. Live donors could be subject to coercion in favor of donating their kidney for they have acquired a commitment with their relatives, society and health teams. Although donation appears in literature as the greatest act of love and solidarity not all live donors are actually willing to give up their kidney. Not all sons and daughters love their parents or parents love their children, nor all siblings love each other. Such important concepts as solidarity and love are not commonly manifest spontaneously in the life of individuals. Love is considered an art which implies giving in a mature manner. Will all donors have this ability? If they lack this ability they are more likely being victims of coercion. As various ethical dilemmas on kidney transplantation exist, bioethics has helped answer many questions in order to furnish an effective support to all who are involved.

Clinical Outcomes of Spousal Donor Kidney Transplantation: Single Center Experience / 대한이식학회지

BACKGROUND: The supply of deceased donors is limited in Korea and most of kidney transplantations are performed using living related or unrelated donors. In this study, we investigated the clinical characteristics and outcomes of spousal donor kidney transplantation at our center. METHODS: From January 2000 to August 2008, we performed 909 cases of kidney transplantations. In this study, 475 one-haplomatch living-related donor (LRD) and 50 spousal donor kidney transplantations were retrospectively analyzed. We compared the outcomes of spousal donor group with those of one-haplomatch LRD group. We also compared the outcomes of husband-to wife with those of wife-to-husband subgroup. RESULTS: The number of Human leukocyte antigen (HLA) mismatch was significantly larger in spousal group (3.3+/-1.2) than in LRD group (2.7+/-0.7). The proportion of tacrolimus use was higher in spousal group (72.0%) than in LRD group (26.6%). The incidence rate of delayed graft function was higher in spousal group (4.0%) than in LRD group (0.4%). There was no significant difference in the incidence of acute rejection between the two groups. Graft survival rates in spousal group (98.0% at 1 year and 91.5% at 5 year) were comparable to those in LRD group (99.6% at 1year and 98.7% at 5 year) (P=0.321). There were no significant differences in the incidence of acute rejection and graft survival rates between the subgroups (husband-to-wife vs. wife-to- husband). CONCLUSIONS: We achieved excellent outcomes by using spousal donor as an option to reduce the donor organ shortage.

Safety analysis of living related live donors in kidney transplantation / 中华泌尿外科杂志

Objective To analyze the clinical outcomes and evaluate the safety of living related live donors in kidney transplantation.Methods One hundre and thirty-two cases of living related donors were studied retrospectively for psychological and physiological parameters. The parameters including life quality, urinalysis, serum biochemistry tests, glomerular filtration rate (GFR) and endogenous creatinine clearance rate (CCr) were analyzed.Results There was no significant difference between living related donors and normal people in the aspect of life quality. In living related donors,SCr was (78.33±15.94)μmol/L before operation and was (108.49±19.88)μmol/L at 7 days postoperation, P＜0.05. SCr was (112.47±20. 38)μmol/L at 6 months post-operation. There was no significant difference in SCr levels between 7 days and 6 months post-operation (P=0. 109). CCr was (95.80±20.92)ml/min in pre-operation and was (57.36±14. 92)ml/min at 7 days post-operation,P＜0.05. CCr was (65. 49±8. 25) ml/min at 6 months post-operation. There was no significant difference in CCr between 7 days and 6 months post-operation.The pre-operative total GFR was(74.08±18.51)ml/min. Of which, the right kidney GFR was (38.43±10.33)ml/min. The residual right kidney GFR was (56. 49±13. 01 ) ml/min 6 months after operation, which decreased 17. 59 ml/min (23.8%) compared with pre-operative total GFR (P＜0.05) and increased 18. 06 ml/min (47.0%) compared to the pre-operative right kidney GFR. Surgical complications included 1 case of splenectomy, 1 case of descending colon rupture and 5 cases of wound fat liquefactions.Conclusion Pre-operatively systemic psychological and physiological evaluation on living related donors, detailed consent consultation, standardized operating techniques, careful perioperative management and strict follow-up can improve the safety of living related donors.

Outcomes of Kidney Transplantation from Spousal Donors: Comparison with Kidney Transplantation from Living-related Donors / 대한신장학회잡지

BACKGROUND: Although transplantation is the best treatment for many people with end-stage renal disease, the gap between the number of organs and the number of potential recipients continues to widen. In addition to living-related individuals, the primary source of donor kidney, the severe organ shortage has led to consideration of genetically unrelated but emotionally related persons as donor candidates. The aim of this study was to compare the results of spousal kidney transplantation with those of living-related kidney transplantation and to analyze the characteristics of spousal kidney transplantation. METHODS: Clinical data were retrospectively analyzed from 21 patients with spousal kidney transplantation and 205 patients with living-related kidney transplantation. Cumulative renal allograft survival was compared between the two groups using Kaplan-Meier curve and log-rank test. Subgroup analysis was done within the patients with spousal kidney transplantation. RESULTS: The patients were significantly older in spousal group (43.7+/-7.8 years) than in living-related group (36.2+/-10.8 years). Donor age was also significantly higher in spousal group (43.0+/-8.4 years) than in living-related group (39.8+/-13.9 years). The number of HLA mismatch was significantly larger in spousal group (3.79+/-1.03) than in living-related group (2.60+/-1.21). The episodes of acute rejection occurring within a year after the transplantation were more frequent in spousal group (5/21) than in living-related group (13/205). Kaplan-Meier curves for cumulative survival of renal allograft revealed no difference between spousal group and living-related group. Renal allograft survival rates in spousal group were 85.2% at 1 year, 75.2% at 5 years, and 67.7% at 10 years after the transplantation. In living-related group, renal allograft survival rates were 96.6% at 1 year, 85.9% at 5 years, and 69.9% at 10 years after the transplantation. Within the patients with spousal kidney transplantation, cumulative renal allograft survival was superior in cases with absent acute rejection, husband-to-wife transplantation, and the number of HLA mismatch less than 5. CONCLUSION: Spousal kidney transplantation shares comparable results with living-related kidney transplantation despite older age, poorer HLA matching and a higher rate of acute rejection. Spousal donor transplants could be a real alternative especially when the donors are husband and the number of HLA mismatch is less than 5.

Long-term Graft Outcome of Living Donor Renal Transplantation: Single Center Experience / 대한이식학회지

PURPOSE: The number of potential renal transplant recipients far exceeds the number of cadaveric donors. For this reason, living-related donors (LRD) and living-unrelated donors (LURD) have been used to decrease the cadaveric donor shortage. We analyzed 571 living donor transplants for 25 years in our center. METHODS: From 1978 to 2003, 571 patients underwent LRD (n=253) or LURD (n=318) kidney transplantation. The patients were divided into precyclosporin era (1978~1987, n=43, era I), cyclosporin era (1988~1997, n=368, era II), and cyclosporin plus mycophenolate- mofetil era (1998~2003, n=160, era III). We compared the graft survival rate of the recipients according to the immunosuppressants and analyzed the variables such as donor's and recipient's age, sex, HLA matching and acute rejection rate. We also compared the long-term survival rate between LRD and LURD. RESULTS: 1 and 10-year graft survival rates of all patients were 94.3% and 75.5%, respectively. 1 and 10-year graft survival rates were 74.4% and 36.2% in era I, 94.3 % and 78.4% in era II. 1 and 5-year graft survival rates were 96.7% and 90.5% in era III (P<0.001). The occurrence rate of acute rejection was 23.3% (era I), 22.3% (era II), and 14.3% (era III) (P=0.000). 1 and 10-year graft survival rates were 92.3% and 81.3% in LRD transplants, and 94.1% and 86.5% in LURD transplants, respectively (P =0.1909). CONCLUSION: The graft survival rates of living donor transplants are improving due to advances of patient care and new immunosuppressive agents. We suggest that living donors will be an important source of kidney transplantations.

Isolated Small Bowel Transplantation from a Living-Related Donor at the Catholic University of Korea: A Case Report of Rejection - Free Course -

The bowel transplantation team at the Catholic Medical Center, Korea, on April 9 2004, accomplished a case of isolated small bowel transplantation (SBT) in a 57 year-old female with short bowel syndrome. The primary surgery was a jejunocolostomy due to mesenteric vein thrombosis, while maintaining 30 cm of the jejunum and colon distal to the splenic flexure. Her renal function was partially unbalanced. During more than 2 years of home TPN, the superior vena cava (VC) and subclavian veins had become occluded, but the inferior VC line remained. SBT was planned due to the repeated life-threatening infections of the last central line. One hundred and fifty centimeter of the distal ileum of the 27 year-old living-related donor, the patient's daughter, was harvested. The graft mesenteric artery and vein were anastomosed to the recipient's inferior mesenteric vessels. A proximal end- to-end jejuno-ileostomy and a distal end-to-side ileo-colostomy of the graft were made, creating a Bishop-Koop enterostomy for graft surveillance. A tube jejunostomy, via a gastrostomy, was established for early feeding and simultaneous gastric drainage. Induction with Daclizumab and immunosuppression consisted of tacrolimus and methylprednisolone, given intravenously, and then mycophenolate mofetil (MMF), enterally from day 3. The patient was discharged on day 42. A CMV infection on day 83 was successfully treated with 3 weeks of gancyclovir therapy. She has been nutritionally independent, with complete oral feeding, and free of rejection until day 170 after the transplantation.

Exchange-donor Program in Renal Transplantation: A single center experience

BACKGROUND: A shortage of kidney donors has produced a progressively increasing gap between the supply of cadaveric kidneys and the demand for cadaveric transplants. Thus, efforts to expand the donor pool have included the use of the living related and unrelated kidney donors in Korea. In certain countries like ours, cadaveric kidney sources are very limited for various reasons, therefore, the living kidney donors have been a major source for uremic patients in our hospital. We propose a new program for donation, in which is an exchange-donor program. It is a program in which the donation is not commercial, but voluntary, thus overcoming the shortage of cadaveric donors, and giving the opportunity for transplant to as many uremic patients as possible. METHODS: Between Jan. 1991 and Dec. 1997, 411 living-donor renal transplants were performed in our hospital. Of those, 61 patients received grafts from exchange donors. We compared the graft survival rate of the exchange-donor transplantations with that of the living related donor transplantations based on the recipient's age and sex, the donor's age and sex, human leukocyte antigens (HLA) mismatching, and the frequency of acute rejection. RESULTS: Fifty-nine (59) of 61 patients were still alive in Dec. 1997, with a median follow-up of 31 months (6-76 months), and the mean serum creatinine level was 1.64 mg/dL. The graft survival rates of the exchange-donor renal transplantations at 1 and 5 years were 92.12% and 80.27%, respectively, and there were no significant differences compared with those of the living related renal transplantations (p=0.1424). The graft survival rates at 1 and 5 years were 93.75% and 81.25%, respectively, for those with more than one HLA-haploidentical pair, and 91.89% and 78.76% for those with less than a one-haplotype match, respectively. The frequency of acute rejection was 37.7% in the exchange-donor group. The renal function of the exchange donors after the donation was not altered, and the postoperative complication rate was 1.6%. CONCLUSIONS: The results show that the graft survival rates of the exchange-donor program were similar to those of the living related renal transplantations, and that the good graft survival rates for the exchange-donor group could not be attributed to better HLA matching. We propose an exchange-donor program that will be able to expand the donor pool and overcome the shortage of cadaveric organ donors.

Risk Factors for Renal Allograft Outcome in Living Related, and Unrelated Renal Transplantation / 대한이식학회지

The lack of available cadaveric organs for transplantation has result in an increased number of kidney transplantation from living donors. In order to characterize correlation of variable factors which affect on the renal graft survival and to compare graft survival of living related donor with that of living unrelated donor, the 515 cases of renal transplantation between January 1979 and December 1997 were reviewed. Each effect of factors included recipient age, donor age, infection, acute rejection, tissue typing, type of donor on graft survival was analyzed as well as the interrelationship on graft survival between six risk factors. It was risk factors which effect on the graft survival that acute rejection, tissue typing and type of donor (P=0.00, P=0.001, P=0.00). The 1 and 5 year graft survival rates of cadaveric renal donor group and acute rejection positive group were 64.8-32.4%, 84.5-49.8% for younger recipient group (50) (0.017). The 1 and 5 year survival rate of cadaveric renal donor group was 42.8% and 28.6% during 1978-1983, 37.5% and 12.5% during 1984-1990 and 100% and 80% during 1991-1997. The grafts survival rate of unrelated living donor is significantly higher than that of cadaveric grafts during 1978-1990 and had a survival rate similar to that of living related donor grafts under all the circumstance given. The tissue typing, acute rejection and type of donor were significant factor which have influence on the graft survival. The cadaveric renal donor & acute rejection had significantly negative effect in older recipients (>50). Recently, the survival rate of cadaveric graft was remarkably increased, but in the future the more data collection for cadaveric graft is required. Living-unrelated renal transplantation provides comparable result to living-related renal transplantation and the unrelated living donor is excellent source of organs for renal transplant recipients.

Risk Factors for Renal Allograft Outcome in Living Related, and Unrelated Renal Transplantation / 대한이식학회지

The lack of available cadaveric organs for transplantation has result in an increased number of kidney transplantation from living donors. In order to characterize correlation of variable factors which affect on the renal graft survival and to compare graft survival of living related donor with that of living unrelated donor, the 515 cases of renal transplantation between January 1979 and December 1997 were reviewed. Each effect of factors included recipient age, donor age, infection, acute rejection, tissue typing, type of donor on graft survival was analyzed as well as the interrelationship on graft survival between six risk factors. It was risk factors which effect on the graft survival that acute rejection, tissue typing and type of donor (P=0.00, P=0.001, P=0.00). The 1 and 5 year graft survival rates of cadaveric renal donor group and acute rejection positive group were 64.8-32.4%, 84.5-49.8% for younger recipient group (50) (0.017). The 1 and 5 year survival rate of cadaveric renal donor group was 42.8% and 28.6% during 1978-1983, 37.5% and 12.5% during 1984-1990 and 100% and 80% during 1991-1997. The grafts survival rate of unrelated living donor is significantly higher than that of cadaveric grafts during 1978-1990 and had a survival rate similar to that of living related donor grafts under all the circumstance given. The tissue typing, acute rejection and type of donor were significant factor which have influence on the graft survival. The cadaveric renal donor & acute rejection had significantly negative effect in older recipients (>50). Recently, the survival rate of cadaveric graft was remarkably increased, but in the future the more data collection for cadaveric graft is required. Living-unrelated renal transplantation provides comparable result to living-related renal transplantation and the unrelated living donor is excellent source of organs for renal transplant recipients.