Post-transplant Graft Survival Research Articles

Chronological and Geographical Variations in the Incidence and Acceptance of COVID-19-Positive Donors and Outcomes Among Abdominal Transplant Patients.

Given the importance of understanding COVID-19-positive donor incidence and acceptance, we characterize chronological and geographic variations in COVID-19 incidence relative to COVID-19-positive donor acceptance. Data on deceased donors and recipients of liver and kidney transplants were obtained from the UNOS database between 2020 and 2023. Hierarchical cluster analysis was used to assess trends in COVID-19-positive donor incidence. Posttransplant graft and patient survival were assessed using Kaplan-Meier curves. From among 38429 deceased donors, 1517 were COVID-19 positive. Fewer kidneys (72.4%vs. 76.5%, p < 0.001) and livers (56.4%vs. 62.0%, p < 0.001) were used from COVID-19-positive donors versus COVID-19-negative donors. Areas characterized by steadily increased COVID-19 donor incidence exhibit the highest transplantation acceptance rates (92.33%), followed by intermediate (84.62%) and rapidly increased (80.00%) COVID-19 incidence areas (p = 0.016). Posttransplant graft and patient survival was comparable among recipients, irrespective of donor COVID-19 status. Regions experiencing heightened rates of COVID-19-positive donors are associated with decreased acceptance of liver and kidney transplantation. Similar graft and patient survival is noted among recipients, irrespective of donor COVID-19 status. These findings emphasize the need for adaptive practices and unified medical consensus in navigating a dynamic pandemic.

Potential Association of Blood Transfusion in Deceased Donors With Outcomes of Liver Transplantation in the United States

BackgroundDonor blood transfusion may potentially affect transplant outcomes through an inflammatory response, recipient sensitization, or transmission of infection. The aim of this study was to evaluate the association of donor blood transfusion with outcomes of liver transplantation (LT). MethodsFrom January 2004 to December 2022, donor blood transfusion information was available for 113,017 adult recipients of LT in the United Network for Organ Sharing database and was classified into 4 levels of transfusion: no-transfusion (N = 68,130), transfusion of 1-5 units (N = 33,629), 6-10 units (N = 8067), and >10 units (N = 5329). Recipient survival analysis was performed by Kaplan–Meier method and multivariable Cox-hazard model. ResultsAmong this cohort, 40.8% of donors (N = 46,261) received blood transfusion during the index hospitalization. Compared to no-blood transfusion donors, blood transfusion donors were younger (median age 37 versus 46 y P < 0.001) and were more brain death donors (94.5% versus 92.1%, P < 0.001). An increased risk of rejection at 6-mo (transfusion 10.3% versus no-transfusion 9.9%, P = 0.055) and 1 y (transfusion 12.5% versus no-transfusion 11.9%, P = 0.0036) post-LT was noted in this cohort. Multivariable Cox-hazard model showed blood transfusion was associated with increased 1-y mortality (transfusion 1.07; 95% CI 1.02-1.12, P = 0.007) and graft failure (transfusion 1.09; 95% CI 1.04-1.13, P < 0.001). ConclusionsDonor blood transfusion was associated with an increased risk of rejection at 6 mo and 1 y among LT recipients and worse post-transplant graft and overall survival. Additional information regarding donor blood transfusion, along with other known factors, may be considered when deciding the optimization of overall immune suppression in LT recipients to decrease the risk of delayed rejection.

Systematic review of the impact of protease-inhibitor-based combination antiretroviral therapy on renal transplant outcomes in recipients living with HIV infection.

Advances in human immunodeficiency virus (HIV) treatment, including combination antiretroviral therapy (cART), have transformed HIV into a chronic condition. Kidney diseases cause morbidity and mortality in patients living with HIV (PLWH), though cART has permitted kidney transplants with acceptable post-transplant graft and patient survival. Risk of allograft rejection remains high, which may be related to interactions between cART, specifically protease inhibitors (PI), and immunosuppressants prescribed post-transplant. This systematic review evaluates renal transplant outcomes in PLWH treated with PI- vs non-PI-based cART. A search strategy was generated with terms related to renal transplant, HIV, and cART and run on PubMed, Embase, Scopus, and Cochrane. Studies were evaluated using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines on Covidence by two reviewers and then evaluated for bias. Of 803 studies, 9 were included. Included papers were prospective or retrospective cohort studies or chart reviews of adult patients. Outcome measures included acute graft rejection, graft survival, and patient survival. One study had significant results demonstrating that PI-based therapy was correlated with increased graft rejection rates. Two studies demonstrated significant graft survival benefit to non-PI-based therapy, while one demonstrated significant benefit to PI-based therapy. Two studies found significant patient survival benefit to non-PI-based therapy. For each outcome measure, remaining data suggested improved outcomes with non-PI-based therapies without achieving statistical significance. The results demonstrate superior outcomes in PLWH taking non-PI-based cART, though the paucity of significant results suggests that PLWH who require PI-based cART for virological control may continue their regimen safely post-kidney transplant.

Performance of risk prediction models for post-liver transplant patient and graft survival over time.

Given liver transplantation organ scarcity, selection of recipients and donors to maximize post-transplant benefit is paramount. Several scores predict post-transplant outcomes by isolating elements of donor and recipient risk, including the donor risk index, Balance of Risk, pre-allocation score to predict survival outcomes following liver transplantation/survival outcomes following liver transplantation (SOFT), improved donor-to-recipient allocation score for deceased donors only/improved donor-to-recipient allocation score for both deceased and living donors (ID2EAL-D/-DR), and survival benefit (SB) models. No studies have examined the performance of these models over time, which is critical in an ever-evolving transplant landscape. This was a retrospective cohort study of liver transplantation events in the UNOS database from 2002 to 2021. We used Cox regression to evaluate model discrimination (Harrell's C) and calibration (testing of calibration curves) for post-transplant patient and graft survival at specified post-transplant timepoints. Sub-analyses were performed in the modern transplant era (post-2014) and for key donor-recipient characteristics. A total of 112,357 transplants were included. The SB and SOFT scores had the highest discrimination for short-term patient and graft survival, including in the modern transplant era, where only the SB model had good discrimination (C ≥ 0.60) for all patient and graft outcome timepoints. However, these models had evidence of poor calibration at 3- and 5-year patient survival timepoints. The ID2EAL-DR score had lower discrimination but adequate calibration at all patient survival timepoints. In stratified analyses, SB and SOFT scores performed better in younger (< 40 y) and higher Model for End-Stage Liver Disease (≥ 25) patients. All prediction scores had declining discrimination over time, and scores relying on donor factors alone had poor performance. Although the SB and SOFT scores had the best overall performance, all models demonstrated declining performance over time. This underscores the importance of periodically updating and/or developing new prediction models to reflect the evolving transplant field. Scores relying on donor factors alone do not meaningfully inform post-transplant risk.

Differential in Kidney Graft Years on the Basis of Solitary Kidney, Simultaneous Liver-Kidney, and Kidney-after-Liver Transplants.

The number of simultaneous liver-kidney (SLK) transplants has significantly increased in the United States. There has also been an increase in kidney-after-liver transplants associated with 2017 policy revisions aimed to fairly allocate kidneys after livers. SLK and kidney-after-liver candidates are prioritized in allocation policy for kidney offers ahead of kidney-alone candidates. We compared kidney graft outcomes of kidney-alone transplant recipients with SLK and kidney-after-liver transplants using paired kidney models to mitigate differences among donor risk factors. We evaluated recipient characteristics between transplant types and calculated differential graft years using restricted mean survival estimates. We evaluated 3053 paired donors to kidney-alone and SLK recipients and 516 paired donors to kidney-alone and kidney-after-liver recipients from August 2017 to August 2022. Kidney-alone recipients were younger, more likely on dialysis, and Black race. One-year and 3-year post-transplant kidney graft survival for kidney-alone recipients was 94% and 86% versus SLK recipients 89% and 80%, respectively, P < 0.001. One-year and 3-year kidney graft survival for kidney-alone recipients was 94% and 84% versus kidney-after-liver recipients 93% and 87%, respectively, P = 0.53. The additional kidney graft years for kidney-alone versus SLK transplants was 21 graft years/100 transplants (SEM=5.0) within 4 years post-transplantation, with no significant difference between kidney-after-liver and kidney-alone transplants. Over a 5-year period in the United States, SLK transplantation was associated with significantly lower kidney graft survival compared with paired kidney-alone transplants. Most differences in graft survival between SLK and kidney-alone transplants occurred within the first year post-transplantation. By contrast, kidney-after-liver transplants had comparable graft survival with paired kidney-alone transplants.

The Effect of New Acuity Circle Policy on Simultaneous Liver and Kidney Transplantation in the United States

New deceased donor liver allocation policy using an acuity circle (AC)-based model was implemented on February 4th, 2020. The effect of AC policy on simultaneous liver-kidney transplantation (SLKT) remains unknown. The aim of this study was to assess the effect of AC policy on SLKT waitlist mortality, transplant probability, and post-transplant outcomes. Using the United Network for Organ Sharing database, 4908 adult SLKT candidates during two study periods, pre-AC (Aug-2017 to Feb-2020, N=2770) and post-AC (Feb-2020 to Dec-2021, N=2138) were analyzed. Outcomes included 90-day waitlist mortality, transplant probability, and post-transplant patient and graft survival. Compared to pre-AC period, SLKT recipients during post-AC period had higher median model for end-stage liver disease (MELD) score (24 vs 23, P<0.001), and less percentage of MELD exception (4.6% vs 7.7%, P=0.001). The 90-day waitlist mortality was same, but the probability of SLKT increased in post-AC period (P<0.001). Post-AC period also saw increased utilization of donation after cardiac death organs (11% vs 6.4%, P<0.001) and decreased rates of transplantation among Black candidates (7.9% vs 13%). After risk adjustment, post-AC period was not associated with any significant difference in 90-day waitlist mortality (sub-distribution hazard ratio [sHR] 0.80; 95% CI 0.56-1.16, P=0.24), and a higher 90-day probability of SLKT (sHR 1.68; 95% CI 1.41-1.99, P<0.001). During post-transplant period, one-year patient survival, liver and kidney graft survival were comparable between two study periods. The AC liver allocation policy was associated with increased transplant probability of adult SLKT candidates without decreasing waitlist mortality, post-transplant patient survival, or liver and kidney graft survival.

Liver transplantation access and outcomes: Impact of variations in liver-specific specialty care

BackgroundWe sought to characterize the impact access to gastroenterologists/hepatologists has on liver transplantation listing, as well as time on the liver transplantation waitlist and post-transplant outcomes. MethodsLiver transplantation registrants aged >18 years between January 1, 2004 and December 31, 2019 were identified from the Scientific Registry of Transplant Recipients Standard Analytic Files. The liver transplantation registration ratio was defined as the ratio of liver transplant waitlist registrations in a given county per 1,000 liver-related deaths. ResultsA total of 150,679 liver transplantation registrants were included. Access to liver transplantation centers and liver-specific specialty physicians varied markedly throughout the United States. Of note, the liver transplantation registration ratio was lower in counties with poor access to liver-specific care versus counties with adequate access (poor access 137.2, interquartile range 117.8–163.2 vs adequate access 157.6, interquartile range 127.3–192.2, P < .001). Among patients referred for liver transplantation, the cumulative incidence of waitlist mortality and post-transplant graft survival was comparable among patients with poor versus adequate access to liver-specific care (both P > .05). Among liver transplantation recipients living in areas with poor access, after controlling for recipient and donor characteristics, cold ischemic time, and model for end-stage liver disease score, the area deprivation index predicted graft survival (referent, low area deprivation index; medium area deprivation index, hazard ratio 1.52, 95% confidence interval 1.03–12.23; high area deprivation index, 1.45, 95% confidence interval 1.01–12.09, both P < .05). ConclusionPoor access to liver-specific care was associated with a reduction in liver transplantation registration, and individuals residing in counties with high social deprivation had worse graft survival among patients living in counties with poor access to liver-specific care.

Right versus left fully robotic live donor nephrectomy and open kidney transplantation: Does the laterality of the donor kidney really matter?

ObjectiveRobotic-assisted live donor nephrectomy (LDN) is being gradually adopted across transplant centers. The left donor kidney is preferred over right due to anatomical factors and ease of procurement. We aimed to study donor and recipient outcomes after robotic procurement and subsequent open implantation of right and left kidneys. MethodsAll fully robotic LDNs and their corresponding open kidney transplants performed at our center between February 2016 and December 2021 were retrospectively analyzed. ResultsOut of 196 robotic LDN (49 [right] vs. 147 [left]), 10 (5.1%) donors had intra-operative events (6.1% [right] vs. 4.8% [left], p=0.71). None of the LDN required conversion to open surgery. The operative times were comparable for the two groups. Nausea (13.3%) was the most common post-operative complication. There was no mortality in either LDN group. Herein, we report our outcomes on 156 recipients (39 right and 117 left allografts) excluding robotic implants, exports, and pediatric recipients. There were no significant differences between right and left kidney recipients with respect to 1-year post-transplant patient survival (100.0% vs. 98.1%, p=0.45) or graft survival (93.9% vs. 97.1%, p=0.11), or delayed graft function (7.7% vs. 5.1%, p=0.55). ConclusionNon-hand-assisted robotic live donor nephrectomies can be safely performed with excellent outcomes. Right LDN was not associated with higher incidence of complications compared to left LDN. Open implantation of robotically procured right renal allografts was not associated with higher risk of recipient complications.

SP5.10 Is there a difference in Survival Outcomes of Dual Kidney Transplants (DKTs) of Allografts Procured from DCD versus DBD Donors in absence of a Dedicated National Pathology Service? A Propensity Score Analysis of UK Transplant Registry. An Epidemiology in Transplant Study Group (ETrSG) Initiative

Abstract Background Dual kidney transplants (DKTs) are generally from supra-marginal or small-for-size kidneys that are implanted to provide optimum total nephron-mass. Glomerulosclerosis Pathology Scoring is used globally to guide whether single or DKT are indicated for transplant. Additionally, there are reported concerns regarding donation after cardiac death (DCD) transplant outcomes’ inferiority to donation after brain death (DBD) transplants but there are no reported survival outcomes of DKT procured from DCD v/s DBD donors. Aim This study aims to research if there is a difference in survival outcomes of DKTs of allografts procured from DCD versus DBD Donors in the UK. Methods In this exploratory analysis, adults who underwent DKT in the UK between Jan 1, 2000, and December 31, 2019, were identified in the NHSBT-Transplant registry data. Post-transplantation graft survival at 1&amp; 3 years was assessed with cox-regression analysis, with propensity scores being used to control for selection bias. Results 51,961 renal transplants were reported to NHSBT during the study period, of whom 525 were DKT. After confounders were controlled for with propensity scores, no significant differences in survival outcomes were found between DCD and DBD transplants. Region of Transplant (OR 1.6, 1.0-2.5; p=0.02), transplant post-Year-2011 (OR 3.0, 1.7-5.2; p&amp;lt;0.00), and non-diabetic donors (OR 2.1, 1.1-3.9, p=0.009) were associated with better graft survival, while DBD transplants were associated with low delayed graft function rates (OR 0.4, 0.27 - 0.59; p&amp;lt;.001). Conclusions Survival outcomes of DKT procured from DCD versus DBD donors are equivalent. These results are admirable as the UK does not have a dedicated National-Pathology-Service to report pre-transplant renal biopsies.

An evaluation of the organ procurement and transplantation network's expanded post-transplant performance metrics

On July 14, 2022, the Organ Procurement and Transplantation Network's (OPTN) Membership and Professional Standards Committee (MPSC) approved bylaws including two new post-transplant performance evaluation metrics, the 90-day (90D) and 1-year conditional on the 90-day (1YC90D) graft survival hazard ratio (HR). These metrics have replaced the previous 1-year (1Y) unconditional, post-transplant graft survival HR and are used to nationally rank and identify programs for MPSC review. The MPSC's policies have major implications for all transplant programs, providers, and patients across the United States. Herein we show two significant limitations with the new evaluation criteria, arbitrary censoring periods and interdependence in the new performance metrics. We have demonstrated a strong and consistent inverse correlation between the new evaluation metrics, thus proving a lack of independence. Moreover, these two evaluation criteria are interdependent even at nominal HRs. Thus, the 90D cohort can be used to accurately predict whether the 1YC90D is above or below a given HR threshold. This could alter practice behaviors and the timing of patient event reporting, which may result in many unintended consequences related to clinical practice. Here we provide the first evidence that this new evaluation system will lead to a significant increase in the number of programs flagged for MPSC review. When this occurs, the cost of operating a transplant program will increase without a clear demonstration of an increased accuracy in identifying problematic programs.

Impact of the Pediatric ABO Policy Change on Listings, Transplants, and Outcomes for Children Younger Than 2 Years Listed for Heart Transplantation in the United States

We assessed the impact of the liberalized ABO pediatric policy change on candidate characteristics and outcomes for children undergoing heart transplant (HT). Children <2 years undergoing HT with ABO strategy reported at listing and HT from December 2011 to November 2020 to the Scientific Registry of Transplant Recipients database were included. Characteristics at listing, HT, and outcomes during the waitlist and post-transplant were compared before the policy change (December 16, 2011 to July 6, 2016), and after the policy change (July 7, 2016 to November 30, 2020). The percentage of ABO-incompatible (ABOi) listings did not increase immediately after the policy change (P = .93); however, ABOi transplants increased by 18% (P < .0001). At listing, both before and after the policy change, ABOi candidates had higher urgency status, renal dysfunction, lower albumin, and required more cardiac support (intravenous inotropes, mechanical ventilation) than those listed ABO compatible (ABOc). On multivariable analysis, there were no differences in waitlist mortality between children listed as ABOi and ABOc before the policy change (adjusted hazard ratio [aHR] 0.80, 95% confidence interval [CI] 0.61-1.05, P = .10) or after the policy change (aHR 1.2, 95% CI 0.85-1.6, P = .33). Post-transplant graft survival was worse for ABOi transplanted children before the policy change (aHR 1.8, 95% CI 1.1-2.8, P = .014), but not significantly different after the policy change (aHR 0.94, 95% CI 0.61-1.4, P = .76). After the policy change, ABOi listed children had significantly shorter waitlist times (P < .05). The recent pediatric ABO policy change has significantly increased the percentage of ABOi transplantations and decreased waitlist times for children listed ABOi. This change in policy has resulted in broader applicability and actual performance of ABOi transplantation with equal access to ABOi or ABOc organs, and thus eliminated the potential disadvantage of only secondary allocation to ABOi recipients.

Outcomes of thymoglobulin versus basiliximab induction therapies in living donor kidney transplant recipients with mild to moderate immunological risk – a retrospective analysis of UNOS database

Introduction The aim of this study is to assess the outcomes of different induction therapies among mild to moderate immunological risk kidney transplants in the era tacrolimus and mycophenolate-derivate based maintenance. Methods This was a retrospective cohort study using data from the United States Organ Procurement and Transplantation Network among mild to moderate immunological risk living-donor KTRs, defined as having first transplant and panel reactive antibodies less than 20% but with two HLA-DR mismatches. KTRs were divided into two groups based on induction therapy with either thymoglobulin or basiliximab. Instrumental variable regression models were used to assess the effect of induction therapy on acute rejection episodes, serum creatinine levels and graft survival. Results Of the entire cohort, 788 patients received basiliximab while 1727 patients received thymoglobulin induction. There were no significant differences between basiliximab versus thymoglobulin induction in acute rejection episodes at one-year post-transplant (coefficient= −0.229, p value = .106), serum creatinine levels at one-year post-transplant (coefficient= −0.024, p value = .128) or death-censored graft survival (coefficient: − <0.001, p value = .201). Conclusion This study showed no significant difference in acute rejection episodes or graft survival when using thymoglobulin or basiliximab in mild to moderate immunological risk living donor KTRs, maintained on tacrolimus and mycophenolate-based immunosuppressive regimen.

Living-Donor Liver Transplant and Improved Post-Transplant Survival in Patients with Primary Sclerosing Cholangitis.

Primary sclerosing cholangitis (PSC) is the leading indication of liver transplantation (LT) among autoimmune liver disease patients. There is a scarcity of studies comparing survival outcomes between living-donor liver transplants (LDLT)s and deceased-donor liver transplants (DDLTs) in this population. Using the United Network for Organ Sharing database, we compared 4679 DDLTs and 805 LDLTs. Our outcome of interest was post-LT patient survival and post-LT graft survival. A stepwise multivariate analysis was performed, adjusting for recipient age, gender, diabetes mellitus, ascites, hepatic encephalopathy, cholangiocarcinoma, hepatocellular carcinoma, race, and the model for end-stage liver disease (MELD) score; donor' age and sex were also included to the analysis. According to univariate and multivariate analysis, LDLT had a patient and graft survival benefit compared to DDLT (HR, 0.77, 95% CI 0.65-0.92; p < 0.002). LDLT patient survival (95.2%, 92.6%, 90.1%, and 81.9%) and graft survival (94.1%, 91.1%, 88.5%, and 80.5%) at 1, 3, 5, and 10 years were significantly better than DDLT patient survival (93.2%, 87.6%, 83.3%, and 72.7%) and graft survival (92.1%, 86.5%, 82.1%, and 70.9%) (p < 0.001) in the same interval. Variables including donor and recipient age, male recipient gender, MELD score, diabetes mellitus, hepatocellular carcinoma, and cholangiocarcinoma were associated with mortality and graft failure in PSC patients. Interestingly, Asians were more protected than Whites (HR, 0.61; 95% CI, 0.35-0.99; p < 0.047), and cholangiocarcinoma was associated with the highest hazard of mortality (HR, 2.07; 95% CI, 1.71-2.50; p < 0.001) in multivariate analysis. LDLT in PSC patients were associated with greater post-transplant patient and graft survival compared to DDLT patients.

Effect of Pre-Transplant Covid-19 Exposure on Post-Liver Transplant Clinical Outcomes

BackgroundCOVID-19 has led to an unprecedented global health crisis. This situation caused an immediate reduction in solid organ transplantation activity. This study aimed to present the follow-up results of patients with chronic liver disease who underwent liver transplantation (LT) after a history of COVID-19 infection. MethodsSociodemographic characteristics and clinicopathological data of 474 patients who underwent LT at Inonu University Liver Transplant Institute between March 11, 2020 and March 17, 2022 were prospectively recorded and analyzed retrospectively. Among these, the data of 35 patients with chronic liver disease who were found to be exposed to COVID-19 infection in the pre-LT period were analyzed for this study. ResultsThe median body mass index, Child score, and Model for end-stage liver disease/ Pediatric end-stage liver disease scores of the 35 patients were calculated as 25.1 kg/m2 (IQR: 7.4), 9 points (IQR: 4), and 16 points (IQR: 10), respectively. Graft rejection occurred in 4 patients at a median of 25 days post-transplant. Five patients underwent retransplantation at a median of 25 days post-transplant. The most common cause of retransplantation is early hepatic artery thrombosis. There were 5 deaths during postoperative follow-up. Mortality developed in 5 (14.3%) patients exposed to COVID-19 infection in the pretransplant period, whereas mortality occurred in 56 (12.8%) patients not exposed to COVID-19 infection. There was no statistically significant difference in mortality between the groups (P = .79). ConclusionsThe results of this study showed that exposure to COVID-19 before LT does not affect post-transplant patients and graft survival.

A pharmacist-led intervention to improve kidney transplant recipient outcomes and identify patients at risk of highly variable trough tacrolimus levels: a cohort study

ObjectivesGiven the positive impact of appropriate medication management on graft outcome and therefore of patient survival and graft function, the pharmacist’s role in the kidney transplantation team has evolved over...

Single-center experience of ex vivo lung perfusion and subsequent lung transplantation.

The safety of lung transplantation using ex vivo lung perfusion (EVLP) has been confirmed in multiple clinical studies; however, limited evidence is currently available regarding the potential effects of EVLP on posttransplant graft complications and survival with mid- to long-term follow-up. In this study, we reviewed our institutional data to better understand the impact of EVLP. Lungs placed on EVLP from 2014 through 2020 and transplant outcomes were retrospectively analyzed. Data were compared between lungs transplanted and declined after EVLP, between patients with severe primary graft dysfunction (PGD3) and no PGD3 after EVLP, and between matched patients with lungs transplanted with and without EVLP. In total, 98 EVLP cases were performed. Changes in metabolic indicators during EVLP were correlated with graft quality and transplantability, but not changes in physiological parameters. Among 58 transplanted lungs after EVLP, PGD3 at 72h occurred in 36.9% and was associated with preservation time, mechanical support prior to transplant, and intraoperative transfusion volume. Compared with patients without EVLP, patients who received lungs screened with EVLP had a higher incidence of PGD3 and longer ICU and hospital stays. Lung grafts placed on EVLP exhibited a significantly higher chance of developing airway anastomotic ischemic injury by 30days posttransplant. Acute and chronic graft rejection, pulmonary function, and posttransplant survival were not different between patients with lungs screened on EVLP versus lungs with no EVLP. EVLP use is associated with an increase of early posttransplant adverse events, but graft functional outcomes and patient survival are preserved.

Outcomes after anti-thymocyte globulin vs Basiliximab induction before deceased donor kidney transplants

BackgroundDeceased donor kidney transplants represent an important source of renal replacement for the 100 000 patients initiating hemodialysis annually. We compared the association of induction therapy, anti-thymocyte globulin [rabbit] (rATG) or basiliximab, with posttransplant rejection, graft and patient survival. MethodsUsing the United Network for Organ Sharing (UNOS) database, we identified patients that received deceased donor kidney transplants. The outcomes analyzed were 6- month rejection, 1-year rejection, patient survival and graft survival. Multivariate logistic regression models were constructed to understand the association of induction therapy and rejection. Cox-proportional hazards models were constructed to ascertain the association of choice of induction therapy with both patient and graft survival. ResultsOf 45 339 patients, 33 906 patients received rATG induction therapy and 11 433 patients received basiliximab induction therapy. The rATG group were younger (53.44 years vs 55.28 years, P < 0.001), more frequently female (58.74% male vs 66.08%, P < 0.001) and more frequently Black (34.78% vs 25.66%, p < 0.001) compared with patients in the basiliximab group.Rejection was more likely with basiliximab compared with rATG at 6 months(OR = 1.64, P < 0.001; 7.81% Basiliximab vs 5.23% rATG)and at 12 months (OR = 1.56, P < 0.001; 8.81% Basiliximab vs 6.31% rATG). Basiliximab induction therapy was associated with worse patient survival, (HR = 1.05, P = 0.017). Basiliximab induction therapy was associated with worse graft survival, (HR = 1.03, P = 0.037). ConclusionThe analysis of the national experience demonstrated favorable rejection, patient survival, and graft survival with rATG usage. Further prospective data are necessary to provide treatment recommendations.

HYPOTHERMIC MACHINE PERFUSION OF THE LIVER. THE REASONS FOR SUCCESS

Machine perfusion is an attractive preservation technique to improve outcomes after transplantation. Based on underlying protective mechanisms two main concepts are described today, both with the same goal to provide oxygen to ischemic tissue. While normothermic machine perfusion (NMP) is rather labor intense and conveys its highest effect when performed instead of cold storage, the concept of hypothermic machine perfusion (HMP) is simpler and used after cold storage in the recipient centre. During re-oxygenation mitochondria immediately initiate the inflammatory cascade of ischemia-reperfusion-injury (IRI), although those features appear significantly less pronounced under cold conditions. In contrast to a normothermic perfusion, hypothermic techniques lead to a functional recovery of the respiratory chain and the Krebs cycle, thereby reloading cellular energy and metabolizing toxic metabolites, including Succinate. Although the preconditioning of mitochondria with cold oxygenation prior to transplantation is repeatedly described since the early days of organ transplantation, an increasing body of supportive literature is seen only recently. Newly published randomized controlled trials confirm this protection and demonstrate less organ injury, less complications including non-anastomotic biliary strictures, lower acute rejection rates and better graft survivals with the use of hypothermic oxygenated perfusion (HOPE). Of great interest is also the simplicity of HOPE, particularly when applied through the portal vein only, enabling the performance of a liver split during perfusion without the risk of arterial injury. In addition, there is increasing evidence how to assess liver viability during HMP through real-time spectroscopy of mitochondrial metabolism. Perfusate levels of Flavin mononucleotide (FMN), released from complex-I during reperfusion correlate with posttransplant complications and graft survival. This review article describes all features of HMP and addresses remaining challenges of this beneficial preservation technique.

Comparison of Thymoglobulin and Grafalon as Induction Agents in Renal Transplantation: A Prospective Study

BackgroundInduction immunosuppression is used to reduce the incidence of acute rejection and prevent delayed graft function. The 2 rabbit anti-thymocyte globulins- thymoglobulin and Grafalon (ATG Fresenius) have been commonly used for induction immunosuppression and treatment of acute rejection in solid organ transplantation. There are very few studies comparing the efficacy and side effects of both the anti-thymocyte globulins therefore this prospective study comparing the 2 types of anti-thymocyte globulins would be of clinical interest. Patients and MethodsThis prospective single center study was conducted at Rabindranath Tagore International Institute of Cardiac Sciences, Kolkata, India from April 2019 to June 2020. Sixty-two ABO-compatible renal transplant recipients were included in the study. They were divided in 2 groups of 31 patients each. One group received thymoglobulin (3 mg/kg) and the second group received Grafalon (6 mg/kg). All patients were followed up for 12 months and the 2 groups were compared for incidence of rejections, infections, graft function, patient survival, and graft survival. ResultsThere was no significant difference in the incidence of rejections, infective episodes, graft function, posttransplant diabetes mellitus, graft survival and patient survival in thymoglobulin or Grafalon groups. The hematological parameters were similar in both groups at 7 days, 1 month, and 6 months of follow-up. The absolute lymphocyte count was significantly lower in the thymoglobulin group at 12 months posttransplant. ConclusionsThymoglobulin and Grafalon were found to be equivalent in terms of safety and efficacy in short term, with no difference in rejections, infections, graft survival, or patient survival.

312.5: Normothermic Machine Perfusion (NMP) Improves Access To Transplantation for Late Liver Re-Transplant Candidates

Introduction: Late liver re-transplantation (LLrT) is a complex surgical procedure. Candidates for LLrT spend longer on the waitlist than primary transplant candidates due to selectivity in accepting organ offers. A service design using NMP was implemented in October 2018 at a single centre to facilitate increased organ utilisation of marginal organs for high-risk recipients. The aim of this study was to assess if this intervention improved access to transplantation. Methods: Adult patients electively listed between 2015 and 2020 for LLrT were identified from the national transplant authority database. Transplant rates prior to (period 1) and after (period 2) local implementation of the NMP service design (October 2018) were compared at the study centre and compared to the collective data from other UK centres. A cause-specific Cox regression model was used, with the period modelled as a time-dependent covariate, and the period*centre interaction being the primary factor of interest. The model was corrected for UKELD, age, indication, and blood type. Post-transplant graft survival was assessed with univariable cox regression. Results: A total of 144 and 338 LLrT candidates were listed in the study and control centres respectively. At the study centre, the likelihood of transplantation within one year of listing increased from 56% to 68%, whilst a reduction in the LLrT rate was observed at other centres (Figure). Multivariable analysis, showed improved transplant access at the study centre in period 2 (period*centre interaction: HR: 1.83, 95%CI: 1.15-2.9, p=0.01). Post-transplant graft survival was not affected by the intervention (HR: 1.06, 95%CI: 0.41-2.69, p=0.903). Discussion: Implementation of the NMP service design significantly improved access to transplantation for LLrT candidates, without compromising graft survival. While organ utilisation benefit for NMP has been demonstrated before, this is a first study showing a direct patient benefit of NMP for patients with long expected waiting times.