Prediction of three-year outcome of renal transplantation from optimal donors versus expanded criteria donors

Kidney transplantation in systemic sclerosis: Advances in graft, disease, and patient outcome

Systemic sclerosis (SSc) is an immune-mediated rheumatic disease characterized by vascular abnormalities, tissue fibrosis, and inflammation. Renal disease occurring in patients with SSc may have a variable clinicopathological picture. However, the most specific renal condition associated with this disease is the scleroderma renal crisis (SRC), characterized by acute onset of renal failure and severe hypertension. SRC develops in about 20% of cases of SSc, especially in those patients with diffuse cutaneous disease. The prognosis of this condition is often negative, with a rapid progression to end-stage renal disease (ESRD). The advent of the antihypertensive angiotensin-converting enzyme inhibitors in 1980 was associated with a significant improvement in patients’ survival and recovery of renal function. However, the prognosis of these patients can still be improved. The dialytic condition is associated with early death, and mortality is significantly higher than among patients undergoing renal replacement therapy (RRT) due to other conditions. Patients with SRC who show no signs of renal functional recovery despite timely blood pressure control are candidates for kidney transplantation (KT). In this review, we reported the most recent advances in KT in patients with ESRD due to SSc, with a particular overview of the risk of disease recurrence after transplantation and the evolution of other disease manifestations.

Extracellular Vesicles Derived from Mesenchymal Stromal Cells Delivered during Hypothermic Oxygenated Machine Perfusion Repair Ischemic/Reperfusion Damage of Kidneys from Extended Criteria Donors

Simple Summary

In this study, we explore for the first time an innovative tool for organ preservation aimed to preventing ischemia reperfusion injury (IRI) in marginal kidneys from expanded criteria donors (ECD) unsuitable for transplantation. Ex vivo hypothermic oxygenated perfusion (HOPE) with and without MSC-derived EV and normothermic reperfusion (NR) with artificial blood composed of bovine hemoglobin were applied on kidneys to evaluate global renal ischemic damage score, renal ultrastructure, mitochondrial distress, apoptosis, cell proliferation index, and the mediators of energy metabolism. Our study demonstrates that kidney conditioning with HOPE+EV arrests the ischemic damage, prevents reoxygenation-dependent injury, and preserves tissue integrity. EV delivery during HOPE can be considered a new organ preservation strategy to increase the donor pool and improving transplant outcome. The originality of our study lies an EV and HOPE combined novel setting use in kidneys from ECD, but also in any condition for graft dysfunction such as ischemia/reperfusion.

Abstract

The poor availability of kidney for transplantation has led to a search for new strategies to increase the donor pool. The main option is the use of organs from extended criteria donors. We evaluated the effects of hypothermic oxygenated perfusion (HOPE) with and without extracellular vesicles (EV) derived from mesenchymal stromal cells on ischemic/reperfusion injury of marginal kidneys unsuitable for transplantation. For normothermic reperfusion (NR), we used artificial blood as a substitute for red blood cells. We evaluated the global renal ischemic dam-age score (GRS), analyzed the renal ultrastructure (RU), cytochrome c oxidase (COX) IV-1 (a mitochondrial distress marker), and caspase-3 renal expression, the tubular cell proliferation index, hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) tissue levels, and effluent lactate and glucose levels. HOPE+EV kidneys had lower GRS and better RU, higher COX IV-1 expression and HGF and VEGF levels and lower caspase-3 expression than HOPE kidneys. During NR, HOPE+EV renal effluent had lower lactate release and higher glucose levels than HOPE renal effluent, suggesting that the gluconeogenesis system in HOPE+EV group was pre-served. In conclusion, EV delivery during HOPE can be considered a new organ preservation strategy for increasing the donor pool and improving transplant outcome.

Outcomes with Tacrolimus-Based Immunosuppression After Kidney Transplantation from Standard- and Extended-Criteria Donors - A Post Hoc Analysis of the Prospective OSAKA Study

BACKGROUND This post hoc analysis of data from the prospective OSAKA study evaluated the efficacy and safety of prolonged- and immediate-release tacrolimus in patients who received kidneys from extended-criteria (ECD) and standard-criteria (SCD) donors. MATERIAL AND METHODS Within the ECD and SCD groups, patients were randomized to one of 4 tacrolimus-based regimens (initial dose): Arm 1, immediate-release tacrolimus (0.2 mg/kg/day); Arm 2, prolonged-release tacrolimus (0.2 mg/kg/day); Arm 3, prolonged-release tacrolimus (0.3 mg/kg/day); Arm 4, prolonged-release tacrolimus (0.2 mg/kg/day) plus basiliximab. All patients received mycophenolate mofetil and bolus corticosteroids; Arms 1-3 also received tapered corticosteroids. ECDs met the definition: living/deceased donors aged ≥60 years, or 50-60 years with ≥1 other risk factor, and donation after circulatory death. Primary composite endpoint: graft loss, biopsy-confirmed acute rejection or renal dysfunction by Day 168. Outcomes were compared across treatment arms with the chi-squared or Fisher's exact test. RESULTS A total of 1198 patients were included in the analysis (ECD: n=620 [51.8%], SCD: n=578 [48.2%]). Patients with kidneys from ECDs were older versus SCDs (mean age, 55.7 vs. 44.5 years, p<0.0001). A higher proportion of patients with kidneys from ECDs versus SCDs met the primary composite endpoint (56.8% vs. 32.4%, p<0.0001). However, no statistically significant differences in clinical outcomes or the incidence of treatment-emergent adverse events were seen between treatment arms within each donor group. CONCLUSIONS Worse outcomes were experienced in patients who received kidneys from ECDs versus SCDs. Prolonged-release tacrolimus provided similar graft survival to the immediate-release formulation, with a manageable tolerability profile.

A Retrospective Cohort Study on Rehospitalization following Expanded Criteria Donor Kidney Transplantation

Background

Expanded criteria donor (ECD) kidneys are commonly used but are associated with increased graft failure. Graft failure is in turn related to rehospitalization within thirty days post transplant. Our goal was to determine whether ECD kidneys independently lead to rehospitalization within 30 days, 1 year, and 2 years after transplant.

Methods

All adult first-time recipients of deceased donor kidneys transplanted from 2003-2012 at our center were reviewed. Models included demographics, medical comorbidities, center for disease control high-risk kidney, ECD kidney, ischemia times, cause of renal failure, immunosuppressive regimen, positive psychiatric screening, alcoholism, surgeon, year the transplant was performed, years on dialysis before transplant, and the number of inpatient hospitalizations within 6 months prior to transplant. We conducted Andersen-Gill modeling and propensity score matching followed by logistic regression. We also used multivariable linear regression to predict average length of stay during rehospitalization.

Results

More ECD patients had a rehospitalization at 1 year (70.3% versus 59%, log-rank test p=0.014). Thirty-day and 2-year time marks were not significant. Andersen-Gill models predicting successive hospitalizations yielded HR of 1.42 (p=0.002) and 1.32 (p=0.015) for ECD patients at 1 and 2 years of after transplantation, respectively. Propensity score matching and logistic regression showed a significant relative risk of 1.630 at one year (p=0.033) and 1.313 at two years (p=0.268). There was no significant association between ECD and subsequent lengths of hospital stay.

Conclusion

Receiving an ECD kidney is independently associated with multiple readmissions within 2 years of transplant but unrelated to length of stay.

Successful Dual Kidney Transplantation After Hypothermic Oxygenated Perfusion of Discarded Human Kidneys

BACKGROUND The recovery of discarded human kidneys has increased in recent years and impels to use of unconventional organ preservation strategies that improve graft function. We report the first case of human kidneys histologically discarded and transplanted after hypothermic oxygenated perfusion (HOPE). CASE REPORT Marginal kidneys from a 78-year-old woman with brain death were declined by Italian transplant centers due to biopsy score (right kidney: 6; left kidney: 7). We recovered and preserved both kidneys through HOPE and we revaluated their use for transplantation by means of perfusion parameters. The right kidney was perfused for 1 h 20 min and the left kidney for 2 h 30 min. During organ perfusion, the renal flow increased progressively. We observed an increase of 34% for the left kidney (median flow 52 ml/min) and 50% for the right kidney (median flow 24 ml/min). Both kidneys had low perfusate's lactate levels. We used perfusion parameters as important determinants of the organ discard. Based on our previous organ perfusion experience, the increase of renal flow and the low level of lactate following 1 h of HOPE lead us to declare both kidneys as appropriate for dual kidney transplantation (DKT). No complications were reported during the transplant and in the post-transplant hospital stay. The recipient had immediate graft function and serum creatinine value of 0.95 mg/dL at 3 months post-transplant. CONCLUSIONS HOPE provides added information in the organ selection process and may improve graft quality of marginal kidneys.

The Need for New Donor Stratification to Predict Graft Survival in Deceased Donor Kidney Transplantation

PURPOSE

The aim of this study was to determine whether stratification of deceased donors by the United Network for Organ Sharing (UNOS) criteria negatively impacts graft survival.

MATERIALS AND METHODS

We retrospectively reviewed deceased donor and recipient pretransplant variables of kidney transplantations that occurred between February 1995 and December 2009. We compared clinical outcomes between standard criteria donors (SCDs) and expanded criteria donors (ECDs).

RESULTS

The deceased donors consisted of 369 patients. A total of 494 transplant recipients were enrolled in this study. Mean age was 41.7±11.4 year (range 18-69) and 273 patients (55.4%) were male. Mean duration of follow-up was 8.8±4.9 years. The recipients from ECD kidneys were 63 patients (12.8%). The overall mean cold ischemia time was 5.7±3.2 hours. Estimated glomerular filtration rate at 1, 2, and 3 years after transplantation were significantly lower in ECD transplants (1 year, 62.2±17.6 vs. 51.0±16.4, p<0.001; 2 year, 62.2±17.6 vs. 51.0±16.4, p=0.001; 3 year, 60.9±23.5 vs. 54.1±18.7, p=0.047). In multivariate analysis, donor age (≥40 years) was an independent risk factor for graft failure. In Kaplan-Meier analyses, there was no significant difference in death-censored graft survival (Log rank test, p>0.05), although patient survival was lower in ECDs than SCDs (Log rank test, p=0.011).

CONCLUSION

Our data demonstrate that stratification by the UNOS criteria does not predict graft survival. In order to expand the donor pool, new criteria for standard/expanded donors need to be modified by regional differences.

Expanding the use of expanded criteria donors in kidney transplantation

PURPOSE

Although the use of kidney allografts from expanded criteria donors (ECD) has increased in recent years, the reported discard rates are also growing. The influence of ECD characteristics on transplant outcomes is still underevaluated.

METHODS

This retrospective study investigated the influence of preimplantation biopsy findings and delayed graft function (DGF) on patient and graft survivals and renal function at 36 months in a cohort of 372 ECD kidney transplant recipients.

RESULTS

Patient and graft survivals were 91.6 and 68.9 %. The incidence of biopsy-proven acute rejection was 31 %. There were no differences in patient (88.6 vs. 91.1 vs. 94.7 vs. 78.6 %, p = 0.10) or graft (78.1 vs. 72.2 vs. 60.5 vs. 62.6 %, p = 0.14) survivals and renal function (41.7 ± 25.6 vs. 39.9 ± 29.9 vs. 38.1 ± 30.6 vs. 37.4 ± 29.2 mL/min, p = 0.79) comparing ECD kidneys with mild, moderate, and severe histological changes or with no preimplantation biopsy, respectively. However, severe scored transplants had the worst death-censored graft survival (OR 3.1, 95 % CI 1.4-6.9, p = 0.007). No significant differences in patient (86.2 vs. 83.4 %, p = 0.17) or graft (73.7 vs. 65.9 %, p = 0.06) survivals and renal function (38.9 ± 28.6 vs. 39.9 ± 28.4 mL/min, p = 0.72) were observed comparing patients with or without DGF. Multivariable analysis found diabetes history as the only independent risk factor for graft loss (OR 2.1, 95 % CI 1.3-3.3, p = 0.003) or patient death (OR 3.1, 95 % CI 1.5-5.8, p < 0.001).

CONCLUSIONS

Within the limitations of sample size and short follow-up time, in this cohort of ECD kidney transplant recipients the severity of histological changes observed in preimplantation biopsies was independently associated with graft loss.