Long-Term Outcomes of Kidney Transplants from Older/Marginal Donors: A Cohort Study.

INTRODUCTION: To safely expand the donor pool, we introduced a strategy of biopsy-guided selection and allocation to single or dual transplantation of kidneys from donors >60 years old or with hypertension, diabetes, and/or proteinuria (older/marginal donors). Here, we evaluated the long-term performance of this approach in everyday clinical practice. METHODS: In this single-center cohort study, we compared outcomes of 98 patients who received one or two biopsy-evaluated grafts from older/marginal donors ("recipients") and 198 patients who received nonhistologically assessed single graft from ideal donors ("reference-recipients") from October 2004 to December 2015 at the Bergamo Transplant Center (Italy). RESULTS: Older/marginal donors and their recipients were 27.9 and 19.3 years older than ideal donors and their reference-recipients, respectively. KDPI/KDRI and donor serum creatinine were higher and cold ischemia time longer in the recipient group. During a median follow-up of 51.9 (interquartile range 23.1-88.6) months, 11.2% of recipients died, 7.1% lost their graft, and 16.3% had biopsy-proven acute rejection (BPAR) versus 3.5, 7.6, and 17.7%, respectively, of reference-recipients. Overall death-censored graft failure (rate ratio 0.78 [95% CI 0.33-2.08]), 5-year death-censored graft survival (94.3% [87.8-100.0] vs. 94.2% [90.5-98.0]), BPAR incidence (rate ratio 0.87 [0.49-1.62]), and yearly measured glomerular filtration rate decline (1.18 ± 3.27 vs. 0.68 ± 2.42 mL/min/1.73 m2, p = 0.37) were similar between recipients and reference-recipients, respectively. CONCLUSIONS: Biopsy-guided selection and allocation of kidneys from older/marginal donors can safely increase transplant activity in clinical practice without affecting long-term outcomes. This may help manage the growing gap between organ demand and supply without affecting long-term recipient and graft outcomes.

Preimplantation Histological Score Associates with 6-Month GFR in Recipients of Perfused, Older Kidney Grafts: Results from a Pilot Study.

BACKGROUND: Biopsy-guided selection of older kidneys safely expands the organ pool, and pretransplant perfusion improves the preservation of these fragile organs. Herein, we studied morphofunctional variables associated with graft outcomes in perfused, histologically evaluated older kidneys. METHODS: This single-center prospective cohort pilot study evaluated the relationships between preimplantation histologic scores and renal perfusion parameters during hypothermic, pulsatile, machine perfusion (MP) and assessed whether these morphofunctional parameters associated with GFR (iohexol plasma clearance) at 6 months after transplantation in 20 consecutive consenting recipients of a biopsy-guided single or dual kidney transplant from >60-year-old deceased donors. RESULTS: The donor and recipient age was 70.4 ± 6.5 and 63.6 ± 7.9 years (p = 0.005), respectively. The kidney donor profile index (KDPI) was 93.3 ± 8.4% (>80% in 19 cases), histologic score 4.4 ± 1.4, and median (IQR) cold ischemia time 19.8 (17.8-22.8 h; >24 h in 5 cases). The 6-month GFR was 41.2 (34.9-55.7) mL/min. Vascular resistances positively correlated with global histologic score (p = 0.018) at MP start and then decreased from 0.88 ± 0.43 to 0.36 ± 0.13 mm Hg/mL/min (p < 0.001) in parallel with a three-fold renal flow increase from 24.0 ± 14.7 to 74.7 ± 31.8 mL/min (p < 0.001). Consistently, vascular resistance reductions positively correlated with global histologic score (p = 0.009, r = -0.429). Unlike KDPI or vascular resistances, histologic score was independently associated with 6-month GFR (beta standardized coefficient: -0.894, p = 0.005). CONCLUSIONS: MP safely improves graft perfusion, particularly in kidneys with severe histologic changes that would not be considered for transplantation because of high KDPI. The preimplantation histologic score associates with the functional recovery of older kidneys even in the context of a standardized program of pulsatile perfusion.

Long-term outcome of renal transplantation from octogenarian donors: A multicenter controlled study.

To assess whether biopsy-guided selection of kidneys from very old brain-dead donors enables more successful transplantations, the authors of this multicenter, observational study compared graft survival between 37 recipients of 1 or 2 histologically evaluated kidneys from donors older than 80 years and 198 reference-recipients of non-histologically evaluated single grafts from donors aged 60 years and younger (transplantation period: 2006-2013 at 3 Italian centers). During a median (interquartile range) of 25 (13-42) months, 2 recipients (5.4%) and 10 reference-recipients (5.1%) required dialysis (crude and donor age- and sex-adjusted hazard ratio [95% confidence interval] 1.55 [0.34-7.12], P = .576 and 1.41 [0.10-19.54], P = .798, respectively). Shared frailty analyses confirmed similar outcomes in a 1:2 propensity score study comparing recipients with 74 reference-recipients matched by center, year, donor, and recipient sex and age. Serum creatinine was similar across groups during 84-month follow-up. Recipients had remarkably shorter waiting times than did reference-recipients and matched reference-recipients (7.5 [4.0-19.5] vs 36 [19-56] and 40 [24-56] months, respectively, P < .0001 for both comparisons). Mean (± SD) kidney donor risk index was 2.57 ± 0.32 in recipients vs 1.09 ± 0.24 and 1.14 ± 0.24 in reference-recipients and matched reference-recipients (P < .0001 for both comparisons). Adverse events were similar across groups. Biopsy-guided allocation of kidneys from octogenarian donors permits further expansion of the donor organ pool and faster access to a kidney transplant, without increasing the risk of premature graft failure.

Low-dose RATG with or without basiliximab in renal transplantation: a matched-cohort observational study.

BACKGROUND/AIMS: In renal transplantation, peri-operative low-dose rabbit-antithymocyte-globulin (RATG) plus basiliximab induction prevented acute allograft rejection more effectively than post-operative RATG plus basiliximab induction. We investigated the specific antirejection contribution of basiliximab in this context. METHODS: This single-center, observational, matched-cohort study evaluated allograft rejections (primary outcome), steroid exposure and side effects, GFR (iohexol plasma clearance) and treatment costs in 16 deceased-donor renal transplant recipients induced with RATG (0.5 mg/kg/day) and 32 age-, gender- and treatment-matched reference-patients given RATG plus basiliximab (20 mg on days 0 and 4). RESULTS: Induction was well tolerated. At 18 months, 8 patients (50%) vs. 3 reference-patients (9.4%) rejected the graft [HR (95% CI): 6.53 (1.73-24.70), p = 0.006]. Difference was significant (p < 0.01) even after adjusting for recipient/donor age and gender, cold ischemia time and HLA mismatches. There were 1 antibody-mediated rejection and 2 moderate cellular rejections in patients vs. none in reference-patients (p = 0.032). The median (interquartile range) prednisone cumulative dose was remarkably higher in patients than reference-patients [4.78 (1.12-6.10) vs. 0.19 (0.18-3.81) grams, p = 0.002]. Three patients vs. 24 reference-patients were off-steroid at study end (p < 0.001). Three patients vs. no reference-patient developed new-onset diabetes (p = 0.003). Both inductions similarly depleted B-cells. Outcomes of AZA- vs. MMF-treated participants were similar. GFR was similar in all groups. Compared to MMF, AZA therapy saved ≈ EUR 2,500/year and by month 14.3 post-transplant compensated basiliximab costs. CONCLUSION: In renal transplantation, basiliximab plus peri-operative low-dose RATG more efficiently prevented allograft rejection than RATG monotherapy, and minimized steroid exposure and toxicity. AZA- vs MMF-based maintenance immunosuppression largely compensated the extra costs of basiliximab.

Perioperative Minimal Induction Therapy: A Further Step toward More Effective Immunosuppression in Transplantation.

Dual induction with low doses of rabbit anti-human thymoglobulin (RATG) and basiliximab effectively and safely prevented allograft rejection in high-risk renal transplant recipients. To assess whether treatment timing affects efficacy and tolerability, in this single-center, matched-cohort study, we compared posttransplant outcomes in 25 patients and 50 gender-, age-, and treatment-matched reference patients induced with the same course of 7 daily RATG infusions (0.5 mg/kg/day) started before or after engraftment, respectively. All subjects received basiliximab (20 mg) before and 4 days after transplantation, withdrew steroids within 6 days after surgery, and were maintained on steroid-free immunosuppression with cyclosporine and mycophenolate mofetil or azathioprine. Over 12 months after transplant, 1 patient (4%) and 13 reference patients (26%) had acute rejection episodes. One patient and 5 reference-patients required dialysis therapy because of delayed graft function. In all patients circulating CD4+ and CD8+ T lymphocytes were fully depleted before engraftment. Both treatments were well tolerated. In kidney transplantation, perioperative RATG infusion enhances the protective effect of low-dose RATG and basiliximab induction against graft rejection and delayed function, possibly because of more effective inhibition of early interactions between circulating T cells and graft antigens.

The Bergamo Kidney Transplant Program.

Since the beginning of transplant activities in 1989, the Kidney Transplant Center at the Ospedali Riuniti Bergamo has based its clinical program on the most recent achievements of transplant medicine, in order to optimize the outcome of kidney grafts and improve the quality of life of kidney transplant recipients. Although the transplantation community attempts to keep up with increasing demand for transplantable organs, the supply continues to fall far short of the need. This observation prompted us to focus on the expansion of the available pool of deceased donor organs. In 1997, we established a dual kidney transplant program for donors older than 60 years based on a pretransplant histology protocol with a scoring system ranging from low-dose RATG and delayed CsA administration has been successfully adopted in this population of kidney transplant recipients in our routine clinic practice. In kidney transplantation, chronic deterioration of renal function and death with a functioning graft, mainly due to side effects of the medications, represents a major limitation for long-term success of many transplant programs. We recently documented that per-protocol biopsy more than one year after kidney transplantation is a safe procedure to guide change of conventional immunosuppressive regimens and to lower the risk of major drug-related side effects. In particular, substantial reduction of the CsA dose, leading to extremely low CsA trough level, has no major detrimental effect on renal function and histology during 3 years follow-up, while patients remain free of rejection episodes with concomitant steroid and azathioprine therapy. Novel induction therapies with Campath-1H or Simulect and low-RATG have also helped to minimize maintenance immunosuppression in most patients largely avoiding the use of corticosteroids, Monitoring a patient's exposure to immunosuppressive agents is a critical issue in a minimum of 0 (no renal lesions) to a maximum of 12 (marked changes in renal parenchyma). The assumptions of the proposed algorithm to guide acceptance of single suboptimal or dual marginal kidneys for transplantation were validated in a prospective pilot study involving centers in Europe and North America. Whether the encouraging short-term data translate into improved graft survival is currently a matter of investigation in a prospective, multicenter, matched-cohort trial. As kidneys from marginal donors have an increased risk of delayed graft function, we also studied strategies to manage and prevent this complication. A dual immunosuppressive regimen of basiliximab and transplantation. By pharmacokinetics studies, we documented that a fixed dose regimen of MMF--adopted in the majority of transplant units worldwide--might no longer be the best approach for the management of transplant patients, and MPA pharmacokinetic monitoring is advised. Similarly, we reported pharmacokinetic interaction of concomitant immunosuppression on blood levels of the new immunosuppressant sirolimus. We have a special multiorgan transplant program at our center for patients affected by rare diseases, such as the recurrent hemolytic uremic syndrome (HUS). Based on genotyping for complement factor H-1, membrane co-factor protein or factor I gene mutations, we are exploring the possibility of combining liver and renal transplant or performing renal transplant alone in patients with recurrent HUS who have end-stage renal disease. The achievements of our clinical center are the result of the continuous support by an intense clinical and basic research program. This has allowed us to create a unique model to address the major challenges of transplant medicine.