Yong W. Cho

Risk Factors for Graft Survival After Liver Transplantation from Donation After Cardiac Death Donors: An Analysis of OPTN/UNOS Data

Due to increasing use of allografts from donation after cardiac death (DCD) donors, we evaluated DCD liver transplants and impact of recipient and donor factors on graft survival. Liver transplants from DCD donors reported to UNOS were analyzed against donation after brain death (DBD) donor liver transplants performed between 1996 and 2003. We defined a recipient cumulative relative risk (RCRR) using significant risk factors identified from a Cox regression analysis: age; medical condition at transplantation; regraft status; dialysis received and serum creatinine. Graft survival from DCD donors (71% at 1 year and 60% at 3 years) were significantly inferior to DBD donors (80% at 1 year and 72% at 3 years, p < 0.001). Low‐risk recipients (RCRR ≤ 1.5) with low‐risk DCD livers (DWIT < 30 min and CIT < 10 h, n = 226) achieved graft survival rates (81% and 67% at 1 and 3 years, respectively) not significantly different from recipients with DBD allografts (80% and 72% at 1 and 3 years, respectively, log‐rank p = 0.23). Liver allografts from DCD donors may be used to increase the cadaveric donor pool, with favorable graft survival rates achieved when low‐risk grafts are transplanted in a low‐risk setting. Whether transplantation of these organs in low‐risk recipients provides a survival benefit compared to the waiting list is unknown.

Analyses of the unos scientific renal transplant registry at three years-yearly events affecting transplant success

The success of cadaveric renal transplants in the first year is determined largely by events that transpire during the transplant hospitalization. This conclusion is based upon analyses of data on 19,525 cadaver donor renal transplants performed since October 1987 and reported to the UNOS Scientific Renal Transplant Registry from more than 200 centers nationwide. Graft survival rates at 1 year differed by 20–30% depending upon whether or not the transplanted kidney functioned immediately and upon whether the patient required dialysis during the first week posttransplant, experienced rejection, or was discharged with a kidney that was functioning well. Recipients whose discharge serum creatinine level was less than 2.6 mg/dl or whose graft was functioning well at the time of discharge had 88% 1-year graft survival. A multistep logistic regression analysis showed cold ischemia time, transfusions, donor age and cause of death, HLA-DR mismatches, and peak

Risk factors for development of new-onset diabetes mellitus after kidney transplantation.

Background. New-onset diabetes mellitus after kidney transplantation (NODM) is an important co morbid condition that is associated with inferior graft and patient survival. The objective of this study was to identify donor, recipient and transplant factors, and choices of immunosuppression associated with development of NODM using Organ Procurement Transplant Network/United Network of Organ Sharing database (OPTN/UNOS). Methods. From January 2004 to December 2005, 15,309 adult kidney transplants alone with at least one follow-up report as of March 2006 were identified in the OPTN/UNOS database. Among these, 1,581 patients developed NODM during the follow-up period. We examined the risk factors of NODM using multivariate Cox regression analysis using the time to diagnosis of NODM as a time-varying end point. Other events such as graft loss, patient death, and lost to follow-up were censored. Results. NODM was reported in 10% in our study population with mean follow-up time of 306 days. After adjusting for other known factors, independent factors associated with the development of NODM included recipient age (29% increase of relative risk [RR] for every 10-year age increment), obesity (RR=1.39 for body mass index [BMI] 25–30 and RR=1.85 for BMI>30 vs. BMI<25), tacrolimus use (RR=1.50), hepatitis C virus (HCV) positivity (RR=1.42), and African-American recipients (RR=1.32). Alemtuzumab was associated with a lower risk of NODM (RR=0.52). Discussion. Using OPTN/UNOS database, we identified risk factors for development of NODM. Some of these factors are potentially modifiable, including obesity, HCV infection, and the use of tacrolimus. Clinical trials are needed to assess whether modifying these “modifiable risk factors” will indeed prevent NODM.

Comparison of renal allograft outcomes in combined liver-kidney transplantation versus subsequent kidney transplantation in liver transplant recipients: Analysis of UNOS Database.

Background. There may be an allograft-enhancing effect by the liver on the renal allograft in the setting of simultaneous combined liver-kidney transplantation (CLKT) from the same donor. This study was performed to investigate whether an existing liver allograft could protect a kidney allograft from immunologic injury due to histoincompatibility in liver transplant recipients who received sequential kidney transplantation (KALT). Methods. Using the United Network for Organ Sharing database covering January 1996 to December 2003, outcomes of 352 KALT were compared to 1,136 CLKT. Incidence of acute and chronic rejection and rejection-free renal graft survival was compared between two groups. Results. Renal half-life of KALT allografts was shorter than CLKT group (6.6±0.9 vs. 11.7±1.3 years, P<0.001). Incidence of chronic rejection in KALT group was higher than CLKT group (4.6 vs. 1.2%, P<0.001). One and three-year rejection-free renal graft survival of KALT and CLKT groups were different (77% and 67% KALT vs. 85% and 78% CLKT, respectively; P<0.001). Among human leukocyte antigen mismatched and sensitized patients, rejection-free renal graft survival of KALT group was inferior to the CLKT group (75% at 1 year and 61% 3 years vs. 86% at 1 year and 79% 3 years, P<0.001). Conclusion. Liver allograft provided renal graft immunoprotection if both organs are transplanted simultaneously (immunogenetic identity), but not for kidneys transplanted subsequently.

Pulsatile perfusion reduces the incidence of delayed graft function in expanded criteria donor kidney transplantation.

The use of expanded criteria donors (ECD) has been proposed to help combat the discrepancy between organ availability and need. ECD kidneys are associated with delayed graft function (DGF) and worse long‐term survival. The aim of this study is to evaluate the impact of pulsatile perfusion (PP) on DGF and graft survival in transplanted ECD kidneys. From January 2000 to December 2003, 4618 ECD kidney‐alone transplants were reported to the United Network for Organ Sharing. PP was performed on 912 renal allografts. The prognostic factors of DGF were analyzed using multivariate logistic regression analysis. Risk factors for reduced allograft viability were greater in donors and recipients of PP kidneys. Three‐year graft survival of ECD kidneys preserved with PP was similar to cold storage (CS) kidneys. The incidence of DGF in PP kidneys was significantly lower than CS kidneys (26% vs. 36%, p < 0.001). Despite having a greater number of risk factors for reduced graft viability, the ECD‐PP kidneys had similar graft survival compared to ECD‐CS kidneys. The use of PP, by decreasing the incidence of DGF, may possibly lead to lower overall costs and increased utilization of donor kidneys.

Kidney Allograft and Patient Survival in Type I Diabetic Recipients of Cadaveric Kidney Alone Versus Simultaneous Pancreas/Kidney Transplants: A Multivariate Analysis of the UNOS Database

Simultaneous pancreas-kidney transplant (SPK) is now a common treatment for insulin-dependent diabetic patients with end-stage renal disease. Renal graft survival rates after SPK have been less well studied. This study compared the kidney survival results for 3642 SPK and 2374 cadaveric renal transplants (CRT) in type I diabetic patients at 112 US transplant centers reported to UNOS during 1994 through 1997. The analysis included follow-up information through September 2000. The kidney graft survival rates were significantly lower among recipients of CRT compared with SPK recipients (P < 0.001). Patients who received SPK were younger, less often sensitized, transplanted after shorter periods on dialysis, and less often black. The donors of SPK organs were younger, more often died from head trauma, were less often female, and more often black. SPK renal grafts were transplanted with a shorter cold ischemia time to more poorly HLA-matched recipients. After adjustment of these and other factors, whether a patient was recipient of CRT or SPK was not associated with increased risk of kidney graft failure or patient death. SPK recipients experienced half the rate of delayed kidney function (11% versus 23%) but nearly double the rate of rejections during the initial hospitalization (15% versus 9%) compared with CRT recipients. SPK was associated with better renal allograft survival compared with CRT, despite a higher rate of renal allograft rejection. This observation was explained by favorable donor and recipient factors in the SPK group. After controlling for these factors, SPK provided no protective or detrimental effect on short-term renal allograft or patient survival.

Patient and Graft Outcomes from Deceased Kidney Donors Age 70 Years and Older : An Analysis of the Organ Procurement Transplant Network/United Network of Organ Sharing Database

Background. The organ shortage has resulted in more use of older deceased donor kidneys. Data are limited on the impact of donor aged 70 years and older on transplant outcomes. We examined patient and graft outcomes of renal transplant from expanded criteria donors (ECDs) aged 70 years and older, using the Organ Procurement Transplant Network/United Network of Organ Sharing database. Methods. We identified 601 deceased donor transplants from donors older than 70 years from 2000 to 2005. The follow-up time was until May 2007. Allograft and patient survival were compared between recipients of transplants from older ECDs (age ≥70) and younger ECDs (age 50–69). The relative risk of graft loss and patient death were determined using multivariate models. Results. The adjusted relative risks of overall graft loss (hazards ratio [HR] 1.37; 95% confidence interval [CI] 1.19–1.58), death-censored graft loss (HR 1.32; 95% CI 1.09–1.61), and patient death (HR 1.37; 95% CI 1.15–1.64) were greater among recipients of transplants from older ECD kidneys. The relative risk of patient death was lower when older ECD kidneys were transplanted into recipients older than 60 compared with recipients aged 41 to 60. In contrast, the relative risk of death-censored graft loss was not increased when older ECD kidneys were transplanted into recipients older than 60. Conclusions. Transplants from older ECD kidneys are associated with a higher risk of graft loss and patient death. The risk was highest when older ECD kidneys were transplanted into recipients younger than 60 years.

Expanding the Donor Kidney Pool: Utility of Renal Allografts Procured in a Setting of Uncontrolled Cardiac Death

The chronic shortage of deceased kidney donors has led to increased utilization of donation after cardiac death (DCD) kidneys, the majority of which are procured in a controlled setting. The objective of this study is to evaluate transplantation outcomes from uncontrolled DCD (uDCD) donors and evaluate their utility as a source of donor kidneys.

Analysis of the United Network for Organ Sharing database comparing renal allografts and patient survival in combined liver-kidney transplantation with the contralateral allografts in kidney alone or kidney-pancreas transplantation.

Background. Combined liver-kidney transplantation (LKT) is the accepted treatment for patients with liver failure and irreversible renal insufficiency. Controversy exists as to whether simultaneous LKT with organs from the same donor confers immunologic and graft survival benefit to the kidney allograft. This study compares the outcomes of simultaneous LKT with the contralateral kidneys used for kidney alone transplantation (KAT) or combined pancreas-kidney transplantation (PKT) to understand the factors that account for the differences in survival. Methods. From October 1987 to October 2001, LKTs with organs from 899 cadaver donors were reported to the United Network for Organ Sharing; 800 contralateral kidneys from these donors were used in 628 KAT and 172 PKT recipients. These 800 paired control patients were the basis of this analysis. Results. Graft and patient survival rates were lower among LKT recipients compared with KAT (P <0.001) and PKT recipients (P <0.001), because of a higher patient mortality rate during the first 3 months posttransplant. Among human leukocyte antigen-mismatched transplants, LKT recipients demonstrated the highest 1-year rejection-free survival rate (LKT 70%, KAT 61%, and PKT 57% ) (P =0.005 vs. KAT, P =0.005 vs. PKT). There was a lower incidence of renal graft loss resulting from chronic rejection among LKT recipients (LKT 2% vs. KAT 8% vs. PKT 6%, P <0.0001). Conclusions. Patients undergoing LKT exhibit a higher rate of mortality during the first year posttransplant compared with patients undergoing KAT and KPT. Analysis of the data indicates an allograft-enhancing effect of liver transplantation on the renal allograft.

Outcomes of Dual Adult Kidney Transplants in the United States: An Analysis of the OPTN/UNOS Database

Background. The organ shortage has resulted in increased use of kidneys from expanded criteria donors (ECD). For ECD kidneys unsuitable for single use, dual kidney transplants (DKT) may be possible. There are limited data comparing outcomes of DKT to single kidney ECD transplants, making it unclear where DKT fits in the current allocation scheme. Our purpose was to compare outcomes of DKT and ECD transplants in the United States. Methods. From 2000 to 2005, a total of 625 DKT, 7686 single kidney ECD, and 6,044 SCD transplants from donors aged ≥50 years were identified from the Organ Procurement and Transplantation Network/United Network for Organ Sharing data. Allograft survival was the primary outcome. Results. DKT comprised 4% of kidney transplants from donors aged ≥50 years. Compared to the ECD donor group, the DKT donor group was older (mean age 64.6±7.7 years vs. 59.9±6.2 years) and consisted of more African Americans (13.1% vs. 9.9%), and more diabetic donors (16.3% vs. 10.4%; P<0.001). Mean cold ischemic time was longer in DKT (22.2±9.7 hr), but rates of delayed graft function were lower (29.3%) compared to ECD transplants (33.6%, P=0.03). Three-year overall graft survival was 79.8% for DKT and 78.3% for ECD transplants. Conclusion. DKT were infrequent and had outcomes comparable to ECD transplants, despite the use of organs from higher risk donors. With a more upfront approach to DKT by offering this option to patients at the time of wait-listing as part of an ECD algorithm, we may be able to further optimize outcomes of DKT and minimize discard of potential organs.