What's the score? A comparison of deceased donor kidney scoring systems and correlation with graft outcome.

BACKGROUND: A number of deceased donor kidney scoring systems have been developed to predict post-transplant graft failure. However, studies comparing the predictive ability of these scoring systems to each other are lacking. METHODS: We used single-center histopathologic and UNOS data from 140 marginal deceased donor kidneys and transplant recipients to compare the predictive accuracy of the Maryland Aggregate Pathology Index (MAPI), Kidney Donor Risk Index (KDRI), Remuzzi, and Nyberg scoring systems for 2-year graft survival using time-dependent receiver operating curves and Kaplan-Meier analysis. RESULTS: MAPI had the highest predictive accuracy (area under curve [AUC] = 0.81) compared to KDRI (AUC = 0.45), Remuzzi (AUC = 0.59), and Nyberg (AUC = 0.63) for 2-year graft survival. Furthermore, when analyzing each score according to its pre-defined risk strata, MAPI was the only scoring system for which 2-year graft survival was significantly different across strata (84.3% for low risk, 56.5% for intermediate risk, and 50% for high risk, P < .001). Additionally, MAPI was the only risk score significantly associated with 2-year graft survival (hazard ratio per point: 1.12, 95% confidence interval [CI]: 1.01-1.23, P = .03). CONCLUSIONS: In a single-center cohort of biopsied marginal kidneys used for transplantation, MAPI had the best predictive ability of these four scoring systems. When biopsy data are available for kidneys considered for transplantation, the MAPI score may provide additional information that could be used to better identify kidneys likely to have longer graft survival.

Validation of the Maryland Aggregate Pathology Index (MAPI), a pre-implantation scoring system that predicts graft outcome.

Predicting graft outcome after renal transplantation based on donor histological features has remained elusive and is subject to institutional variability. We have shown in a retrospective study that the Maryland Aggregate Pathology Index score reliably predicts graft outcome. We sought to validate the scoring system in our center and a second transplant center. We analyzed 140 deceased donor kidneys pre-implantation biopsies from center 1 and 65 from center 2. The patients had a mean follow-up of 695 ± 424 and 656 ± 305 d respectively. Although MAPI scores were similar, there were significant differences in donor and recipient parameters between both centers. Despite this, MAPI was predictive of graft outcome for both centers by Cox univariate, multivariate and time dependent ROC analysis. For center 1 and 2, three yr graft survival within each MAPI group was statistically equivalent. The three-yr graft survival at center 1 for low, intermediate, and high MAPI groups were 84.3%, 56.5%, and 50.0%, respectively, p ≤ 0.0001, and at center 2 were 83.3%, 33.3%, and 33.3%, p = 0.006. MAPI, which is based on a pre-implantation biopsy, demonstrated similar predictive and outcome results from both centers. As expanded criteria donors (ECD) criteria have redefined marginal kidneys, MAPI has the potential to further define ECD kidneys, increase utilization, and ultimately improve outcomes.

Regulatory T cells are not predictive of outcomes in a nonhuman primate model of vascularized composite allotransplantation.

BACKGROUND: T regulatory cells (Tregs) have been associated with prolonged allograft survival and tolerance across a wide variety of species and organ types. We used our nonhuman primate model of facial vascularized composite allotransplantation (VCA) to study the association of Tregs with graft outcomes. METHODS: We quantified Tregs in peripheral blood and allograft biopsies from nonhuman primates after heterotopic partial facial segment allotransplantation from major histocompatibility complex class I-mismatched donors using flow cytometry and immunohistochemistry. Immunosuppression consisted of tacrolimus and mycophenolate mofetil without induction or depletional therapies. Circulating and graft skin Treg values were compared with graft outcomes and with histologic grade from concurrent biopsies. RESULTS: Treg proportion in peripheral blood ranged from 0.156% to 9.00% with a mean of 3.34%±0.22%. FoxP3 staining was observed in 3 of 29 graft biopsies. Median circulating Treg value did not predict time to Banff grade II rejection (hazard ratio, 0.9; confidence interval, 0.4-2.2) or graft loss (hazard ratio, 0.5; confidence interval, 0.01-5.3). Animals that experienced rejection did not have significantly different peripheral blood or graft skin Treg values from those that did not. Biopsy specimens with grade I or II rejection were more likely to contain Tregs (25% vs. 0%; P=0.044) despite no difference in concurrent circulating Tregs (3.56% vs. 3.36%; P=0.704). CONCLUSIONS: These findings in a clinically relevant model suggest that Tregs may have limited prognostic value with standard immunosuppressive protocols used in VCA. Further studies are necessary to determine the specific role of Tregs in VCA and any role of Treg monitoring in clinical practice.

Single-port donor nephrectomy provides improved patient satisfaction and equivalent outcomes.

OBJECTIVE: Minimally invasive techniques have expanded the donor pool for living kidney donation. We changed our approach to single-port donor nephrectomy in 2009 and have compared outcomes with traditional multiple-port laparoscopic donor nephrectomy. BACKGROUND: The development of minimally invasive surgical techniques to procure kidneys from living donors has allowed expansion of living donor renal transplantation to account for one third of all renal transplants. Recent technical advancement allows for the entire surgical procedure to be done through a single incision contained within the umbilicus. METHODS: We compared outcomes from 135 single-port donor nephrectomies with an immediately preceding cohort of 100 multiple-port laparoscopic donor nephrectomies. Survey data were collected from both groups to compare outcomes. Additional comparisons were made to total center experience with 1300 laparoscopic donor nephrectomies. RESULTS: A total of 135 patients completed successful single-port donor nephrectomy without major complication or open conversion. Another 16 patients required additional port placement because of excessive intra-abdominal fat or limited abdominal domain. Compared with multiple-port donor nephrectomy, single-port patients had similar operative times to cross clamp (2.8 vs 2.6 hours; P = 0.11) that normalized after a learning curve of approximately 50 cases. Recipient creatinine levels were similar at 1 week and 1 month posttransplant. Although 36-Item Short Form Health Surveys demonstrated no significant differences, additional survey data revealed that single-port patients were more satisfied with cosmetic outcomes (P < 0.01) and the overall donation process (P = 0.01). Single-port approach had similar outcomes compared with all previous laparoscopic donor nephrectomies. CONCLUSIONS: Single-port donor nephrectomy can be integrated as a standardized approach for renal donation without additional donor risk, and with benefits of improved patient satisfaction with cosmetic and overall outcomes. Although the primary benefit is cosmetic, (a single incision predominantly contained within the umbilicus) outcomes justify application for kidney donors in experienced centers and may motivate additional living kidney donation.

Pancreas transplant alone as an independent risk factor for the development of renal failure: a retrospective study.

BACKGROUND: Pancreas transplant alone (PTA) is a controversial procedure. Without clearly demonstrated patient survival, recipients report improved quality of life. Nephrotoxic immunosuppression (IS) may exacerbate diabetic renal injury post-PTA. METHODS: A single institution retrospective review of patients receiving PTA over a 14-year period was completed. Patient and donor demographics, surgical outcomes, rejection, and patient or graft survival were analyzed. Pre- and Postoperative estimated glomerular filtration rates (eGFR) were calculated based on the modification of diet and renal disease. Multivariate analysis was performed. RESULTS: One hundred twenty-three patients undergoing 131 PTAs had an average age of 40.0 years. Seven patients were retransplanted and one received a third pancreas. Mean graft survival was 3.26 years (0-11.3 years) with 21 patients (17%) lost to follow-up. One- and 5-year patient survivals were 96.6% and 91.5%, respectively (mean, 7.15 year). Seventeen patients had an eGFR less than 50 mL/min/1.73 m preoperatively, whereas 64 patients did so post-PTA and 24 had an eGFR less than 30 mL/min. Mean eGFR pretransplantation was 88.9 vs. 55.6 posttransplantation (P<0.0001) with mean follow-up of 3.68 years. All but 16 (12%) patients showed a decrease in eGFR. Mean decrement was 32.1 mg/min/1.73 m. Thirteen developed end-stage renal disease chronic kidney disease (CKD 5) requiring kidney transplantation (KT) at a mean of 4.36 years. Eighty-three patients had an episode of rejection. In post-PTA RF, graft survival was 3.2 vs. 2.4 years (P=0.13). In those requiring KT, graft survival was 7.9 vs. 2.9 years (P<0.0001). Cold ischemia times, donor age, and preoperative eGFR for those with and without RF-requiring KT were not significant. Body mass index was statistically significant. Leukocyte-depleting agents was evaluated, but was not significant. All patients received calcineurin inhibitor IS. CONCLUSIONS: Patients who undergo PTA may be at increased risk for RF. After comparing patient and donor demographics, IS, and human leukocyte antigen mismatch, it seems that PTA is an independent risk factor for the development of renal failure. Patients with more successful pancreatic grafts demonstrated lower eGFR. Patients should be made aware of the risks of long-term IS. Only the most appropriate patients should be chosen for PTA.