Retransplantation outcomes for hepatitis C in the United States before and after direct-acting antiviral introduction

The success of direct-acting antiviral (DAA) therapy has led to near-universal cure for patients chronically infected with hepatitis C virus (HCV) and improved post–liver transplant (LT) outcomes. We investigated the trends and outcomes of retransplantation in HCV and non-HCV patients before and after the introduction of DAA. Adult patients who underwent re-LT were identified in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Multiorgan transplants and patients with >2 total LTs were excluded. Two eras were defined: pre-DAA (2009-2012) and post-DAA (2014-2017). A total of 2112 re-LT patients were eligible (HCV: n = 499 pre-DAA and n = 322 post-DAA; non-HCV: n = 547 pre-DAA and n = 744 post-DAA). HCV patients had both improved graft and patient survival after re-LT in the post-DAA era. One-year graft survival was 69.8% pre-DAA and 83.8% post-DAA (P < .001). One-year patient survival was 73.1% pre-DAA and 86.2% post-DAA (P < .001). Graft and patient survival was similar between eras for non-HCV patients. When adjusted, the post-DAA era represented an independent positive predictive factor for graft and patient survival (hazard ratio [HR]: 0.67; P = .005, and HR: 0.65; P = .004) only in HCV patients. The positive post-DAA era effect was observed only in HCV patients with first graft loss due to disease recurrence (HR: 0.31; P = .002, HR 0.32; P = .003, respectively). Among HCV patients, receiving a re-LT in the post-DAA era was associated with improved patient and graft survival.     

Prognostic factors in kidney transplantation in the septuagenarian: a multicenter analysis

Kidney transplant (KT) programs have extended recipient eligibility to those who were previously excluded due to advanced age. We aimed to determine the outcomes of the patients ≥70 years undergoing KT and investigate factors predicting survival. Two thousand six hundred and twenty‐four KT patients between 2003 and 2013 at two institutions were divided into two groups; those ≥70 years (n=300) and those <70 years (n=2324) at the time of KT. Patient survival at 1, 3, and 5 years was 95%, 86%, and 77% in ≥70 years of age group and 98%, 95%, and 90% in the <70 years group (P<.001). When graft loss due to death was censored, graft survival was not significantly different between the two groups (P=.18). On multivariable analysis, the significant predictors of inferior survival in patients ≥70 years included: body mass index (BMI)>30 kg/m² (hazard ratio [HR] 1.07; P=.01), panel reactive antibody (PRA)>20% (HR 2.38; P=.01), previous coronary artery bypass grafting (CABG; HR 1.95; P=.03) and peripheral vascular disease (PVD; HR 2.60; P=.04). Acceptable outcomes can be achieved in KT recipients ≥70 years. Caution should be used when listing these patients if they have BMI>30 kg/m², PRA>20%, CABG or PVD.     

Use of expanded-criteria donors and > 85 KDPI kidneys for pediatric kidney transplantation in the United States

Pediatric kidney transplant outcomes associated with expanded-criteria donors (ECD) and high Kidney Donor Profile Index (KDPI) kidneys are unknown. We reviewed the Scientific Registry of Transplant Recipients data from 1987-2017 to identify 96 ECD and 92 > 85 KDPI kidney recipients (<18 years). Using propensity scores, we created comparison groups of 375 non-ECD and 357 ≤ 85 KDPI recipients for comparisons with ECD and > 85 KDPI transplants, respectively. We used Cox regression for patient/graft survival and sequential Cox approach for survival benefit of ECD and > 85 KDPI transplantationvs remaining on the waitlist. After adjustment, ECD recipients were at significantly increased risk of graft failure (adjusted hazard ratio [aHR] = 1.6; P = .001) but not of mortality (aHR = 1.33; P = .15) compared with non-ECD recipients. We observed no survival benefit of ECD transplants vs remaining on the waitlist (aHR = 1.05; P = .83). We found no significant difference in graft failure (aHR = 1.27; P = .12) and mortality (aHR = 1.41; P = .13) risks between > 85 KDPI and ≤ 85 KDPI recipients. However, > 85 KDPI transplants were associated with a survival benefit vs remaining on the waitlist (aHR = 0.41; P = .01). ECD transplantation in children is associated with a high graft loss risk and no survival benefit, whereas > 85 KDPI transplantation is associated with a survival benefit for children vs remaining on the waitlist.     

Long‐term survival in visceral transplant recipients in the new era: A single‐center experience

There is a paucity of data on long‐term outcomes following visceral transplantation in the contemporary era. This is a single‐center retrospective analysis of all visceral allograft recipients who underwent transplant between November 2003 and December 2013 with at least 3‐year follow‐up data. Clinical data from a prospectively maintained database were used to assess outcomes including patient and graft survival. Of 174 recipients, 90 were adults and 84 were pediatric patients. Types of visceral transplants were isolated intestinal transplant (56.3%), combined liver‐intestinal transplant (25.3%), multivisceral transplant (16.1%), and modified multivisceral transplant (2.3%). Three‐, 5‐, and 10‐year overall patient survival was 69.5%, 66%, and 63%, respectively, while 3‐, 5‐, and 10‐year overall graft survival was 67%, 62%, and 61%, respectively. In multivariable analysis, significant predictors of survival included pediatric recipient (P = .001), donor/recipient weight ratio <0.9 (P = .008), no episodes of severe acute rejection (P = .021), cold ischemia time <8 hours (P = .014), and shorter hospital stay (P = .0001). In conclusion, visceral transplantation remains a good option for treatment of end‐stage intestinal failure with parenteral nutritional complications. Proper graft selection, shorter cold ischemia time, and improvement of immunosuppression regimens could significantly improve the long‐term survival.     

Height mismatch: An overlooked component of adult heart transplant outcomes

Heart transplantation guidelines recommend against matching donors with significant weight but not height discrepancies. This study analyzed the impact of donor-recipient height mismatch on mortality among heart transplant recipients. We retrospectively analyzed all adult patients in the United Network for Organ Sharing (UNOS) registry undergoing heart transplantation from 1990 to September 2016. Moderate and severe height mismatch were classified as >10% and >15% difference in donor height from recipient height, respectively. The primary outcome was 1-year mortality. Adjusted Cox hazards regression was performed, and Kaplan-Meier estimates illustrated 10-year survival. Of 44 877 transplants, 4822 (10.7%) were moderately height mismatched. Height-mismatched recipients were more frequently female (41.6% vs 21.8%, P < .001), sex mismatched (53.8% vs 24.9%, P < .001), and weight mismatched (4.9% vs 1.9%, P < .001). After adjustment, recipients of moderately (HR = 1.15 [1.02-1.30]) and severely (HR = 1.38 [1.10-1.74]) taller donor hearts were at increased risk of mortality at 1 year relative to height-matched recipients. Furthermore, of 1042 (21.6%) severe mismatches, recipients with taller (HR = 1.39 [1.11-1.74]) but not shorter (HR = 0.79 [0.44-1.43]) donors faced increased 10-year mortality. The effect was pronounced among re-transplant candidates (HR = 1.96 [1.07-3.59]). In conclusion, matching with moderately or severely taller donors is an independent predictor of mortality among primary and re-transplant candidates.     

Quantifying infection risks in incompatible living donor kidney transplant recipients

Desensitization has enabled incompatible living donor kidney transplantation (ILDKT) across HLA/ABO barriers, but added immunomodulation might put patients at increased risk of infections. We studied 475 recipients from our center from 2010 to 2015, categorized by desensitization intensity: none/compatible (n = 260), low (0-4 plasmaphereses, n = 47), moderate (5-9, n = 74), and high (≥10, n = 94). The 1-year cumulative incidence of infection was 50.1%, 49.8%, 66.0%, and 73.5% for recipients who received none, low, moderate, and high-intensity desensitization (P < .001). The most common infections were UTI (33.5% of ILDKT vs. 21.5% compatible), opportunistic (21.9% vs. 10.8%), and bloodstream (19.1% vs. 5.4%) (P < .001). In weighted models, a trend toward increased risk was seen in low (wIRR = _0.771.40_2.56,P = .3) and moderately (wIRR = _0.881.35_2.06,P = .2) desensitized recipients, with a statistically significant 2.22-fold (wIRR = _1.332.22_3.72,P = .002) increased risk in highly desensitized recipients. Recipients with ≥4 infections were at higher risk of prolonged hospitalization (wIRR = _2.623.57_4.88, P < .001) and death-censored graft loss (wHR = _1.154.01_13.95,P = .03). Post–KT infections are more common in desensitized ILDKT recipients. A subset of highly desensitized patients is at ultra-high risk for infections. Strategies should be designed to protect patients from the morbidity of recurrent infections, and to extend the survival benefit of ILDKT across the spectrum of recipients.     

Better graft outcomes from offspring donor kidneys among living donor kidney transplant recipients in the United States

A recent study reported that kidney transplant recipients of offspring living donors had higher graft loss and mortality. This seemed counterintuitive, given the excellent HLA matching and younger age of offspring donors; we were concerned about residual confounding and other study design issues. We used Scientific Registry of Transplant Recipients data 2001‐2016 to evaluate death‐censored graft failure (DCGF) and mortality for recipients of offspring versus nonoffspring living donor kidneys, using Cox regression models with interaction terms. Recipients of offspring kidneys had lower DCGF than recipients of nonoffspring kidneys (15‐year cumulative incidence 21.2% vs 26.1%, P < .001). This association remained after adjustment for recipient and transplant factors (adjusted hazard ratio [aHR] = _0.730.77_0.82, P < .001), and was attenuated among African American donors (aHR _0.770.85_0.95; interaction: P = .01) and female recipients (aHR _0.770.84_0.91, P < .001). Although offspring kidney recipients had higher mortality (15‐year mortality 56.4% vs 37.2%, P < .001), this largely disappeared with adjustment for recipient age alone (aHR = _1.021.06_1.10, P = .002) and was nonsignificant after further adjustment for other recipient characteristics (aHR = _0.930.97_1.01, P = .1). Kidneys from offspring donors provided lower graft failure and comparable mortality. An otherwise eligible donor should not be dismissed because they are the offspring of the recipient, and we encourage continued individualized counseling for potential donors.     

Impact of ureteral stricture and treatment choice on long‐term graft survival in kidney transplantation

We aimed to evaluate the influence of urological complications occurring within the first year after kidney transplantation on long‐term patient and graft outcomes, and sought to examine the impact of the management approach of ureteral strictures on long‐term graft function. We collected data on urological complications occurring within the first year posttransplant. Graft survivals, patient survival, and rejection rates were compared between recipients with and without urological complications. Male gender of the recipient, delayed graft function, and donor age were found to be significant risk factors for urological complications after kidney transplantation (P < .05). Death censored graft survival analysis showed that only ureteral strictures had a negative impact on long‐term graft survival (P = .0009) compared to other complications. Death censored graft survival was significantly shorter in kidney recipients managed initially with minimally invasive approach when compared to the recipients with no stricture (P = .001). However, graft survival was not statistically different in patients managed initially with open surgery (P = .47). Ureteral strictures following kidney transplantation appear to be strongly negatively correlated with long‐term graft survival. Our analysis suggests that kidney recipients with ureteral stricture should be managed initially with open surgery, with better long‐term graft survival.     

Small donor size does not negatively impact outcomes after deceased-donor renal transplantation

Higher body mass index (BMI) of deceased-donors is associated with poorer outcomes in transplant recipients. The effect of low donor BMI on recipient graft function is not clear. Scientific Registry of Transplant Recipients data on recipients of deceased-donor kidneys from 2000 to 2019 were categorized by donor BMI (donor BMI < 18, 18-27, and >27). Primary outcome was death-censored graft survival. The impact of multiple recipient and donor variables, including low donor BMI and the difference between donor and recipient BMI, was evaluated using a multivariate Cox proportional-hazards model. Low BMI donors (LBD) were more likely to be younger, female, and white (all P < .05). LBD were less likely to be Hispanic, diabetic, or have hypertension (all P < .001). LBD recipients were more likely to be younger and female (both P < .001). Low donor BMI was not significantly associated with recipient graft survival. Donor-recipient BMI difference did not correlate with an increased risk of graft failure. Similar results were obtained when donors were classified using body surface area (BSA). Small donor size in terms of BMI or BSA or a large discrepancy between donor and recipient size should not necessarily preclude transplantation of an otherwise acceptable kidney.     

Sirolimus vs mycophenolate mofetil (MMF) in primary combined pancreas and kidney transplantation. Results of a long‐term prospective randomized study

The study was intended to compare pancreas graft survival rates in two groups of pancreas and kidney transplant recipients prospectively randomized to treatment either with sirolimus or MMF. From 2002 to 2013, 238 type 1 diabetic recipients with end‐stage kidney disease were randomized 1:1 to sirolimus or MMF treatment. Noncensored pancreas survival at 5 years was 76.4 and 71.6% for sirolimus and MMF groups, respectively (P > .05). Death‐censored pancreas survival was better in the sirolimus group (P = .037). After removal of early graft losses pancreas survival did not differ between groups (MMF 83.1% vs sirolimus 91.6%, P = .11). Nonsignificantly more grafts were lost due to rejection in the MMF group (10 vs 5; P = .19). Cumulative patient 5‐year survival was 96% in the MMF group and 91% in the sirolimus group (P > .05). Five‐year cumulative noncensored kidney graft survival rates did not statistically differ (85.6% in the sirolimus group and 88.8% in MMF group). Recipients treated with MMF had significantly more episodes of gastrointestinal bleeding (7 vs 0, P = .007). More recipients in the sirolimus group required corrective surgery due to incisional hernias (21 vs 12, P = .019). ClinicalTrials No.: NCT 03582878.     

Role of antithymocyte globulin in patients with hematologic diseases undergoing umbilical cord blood transplantation: A systematic review and meta-analysis

The role of antithymocyte globulin (ATG) in patients with hematologic diseases undergoing umbilical cord blood transplantation (UCBT) remains controversial. This systematic review and meta-analysis was conducted to comprehensively evaluate this issue. PubMed, Embase, and the Cochrane Library were systematically searched. Clinical studies reporting the impact of ATG- vs non-ATG-containing conditioning regimens on transplantation outcomes were identified. Twenty-five studies were included. ATG significantly prevented grade II-IV and grade III-IV acute graft-vs-host disease (GVHD) (11 studies, 5020 patients, HR: 0.49, 95% CI: 0.42-0.56, P < .001; 5 studies, 5490 patients, HR: 0.60, 95% CI: 0.46-0.80, P < .001) but not chronic GVHD (8 studies, 5952 patients, HR: 0.78, 95% CI: 0.51-1.20, P = .266). However, use of ATG was associated with increased transplantation-related mortality and inferior overall survival (9 studies, 4244 patients, HR: 1.79, 95% CI: 1.38-2.33, P < .001; 8 studies, 5438 patients, HR: 1.96, 95% CI: 1.56-2.46, P < .001). Our study did not recommend routine use of ATG in UCBT. Individualizing the ATG timing and dose based on patient characteristics to retain the prophylactic effects of ATG on GVHD without compromising the survival of UCBT recipients may be reasonable.     

Kidney transplant outcomes associated with the use of increased risk donors in children

Increased risk donors (IRDs) may inadvertently transmit blood‐borne viruses to organ recipients through transplant. Rates of IRD kidney transplants in children and the associated outcomes are unknown. We used the Scientific Registry of Transplant Recipients to identify pediatric deceased donor kidney transplants that were performed in the United States between January 1, 2005 and December 31, 2015. We used the Cox regression analysis to compare patient and graft survival between IRD and non‐IRD recipients, and a sequential Cox approach to evaluate survival benefit after IRD transplants compared with remaining on the waitlist and never accepting an IRD kidney. We studied 328 recipients with and 4850 without IRD transplants. The annual IRD transplant rates ranged from 3.4% to 13.2%. IRDs were more likely to be male (P = .04), black (P < .001), and die from head trauma (P = .006). IRD recipients had higher mean cPRA (0.085 vs 0.065, P = .02). After multivariate adjustment, patient survival after IRD transplants was significantly higher compared with remaining on the waitlist (adjusted hazard ratio [aHR]: 0.48, 95% CI: 0.26‐0.88, P = .018); however, patient (aHR: 0.93, 95% CI: 0.54‐1.59, P = .79) and graft survival (aHR: 0.89, 95% CI: 0.70‐1.13, P = .32) were similar between IRD and non‐IRD recipients. We recommend that IRDs be considered for transplant in children.     

Live donor liver transplantation with older donors: Increased long‐term graft loss due to HCV recurrence

Using our prospectively collected database all adult hepatitis C virus (HCV)‐positive patients receiving an adult‐to‐adult LDLT between October 2000 and May 2014 were identified. Outcome of LDLT with grafts from younger (<50 years=128) vs older donors (≥50 years=31) was compared. Post‐transplant graft function, postoperative complications and incidence of HCV recurrence were evaluated. Long‐term graft and patient survival was calculated. No difference in graft function was observed between younger and older grafts. Overall complications were similar between both groups. The severity of complications determined by the Dindo‐Clavien score was similar. Graft loss from HCV recurrence was significantly less frequent in younger grafts (18% vs 62%, P = 0.001). Young vs older livers had a trend toward improved 1‐, 5‐, and 10‐year graft survival (89% vs 87%, 77% vs 69%, 70% vs 55%, P = 0.096), while patient survival was comparable between both groups (91% vs 90%, 78% vs 69%, 71% vs 60%, P = 0.25). In conclusion, LDLT with older vs younger grafts are more frequently associated with long‐term graft loss due to HCV recurrence. Differences in graft survival might be more prominent with prolonged (≥5‐year) follow‐up. Living donor‐recipient matching is particularly important for younger HCV‐positive recipients.     

Survival benefit of accepting livers from deceased donors over 70 years old

Livers from older donors (OLDs; age ≥70) are risky and often declined; however, it is likely that some candidates will benefit from OLDs versus waiting for younger ones. To characterize the survival benefit of accepting OLD grafts, we used 2009‐2017 SRTR data to identify 24 431 adult liver transplant (LT) candidates who were offered OLD grafts eventually accepted by someone. Outcomes from the time‐of‐offer were compared between candidates who accepted an OLD graft and matched controls within MELD ± 2 who declined the same offer. Candidates who accepted OLD grafts (n = 1311) were older (60.5 vs. 57.8 years, P < .001), had a higher median MELD score (25 vs. 22, P < .001), and were less likely to have hepatitis C cirrhosis (14.9% vs. 31.2%, P < .001). Five‐year cumulative mortality among those who accepted versus declined the same OLD offer was 23.4% versus 41.2% (P < .001). Candidates who accepted OLDs experienced an almost twofold reduction in mortality (aHR:_0.450.52_0.59, P < .001) compared to those who declined the same offer, especially among the highest MELD (35‐40) candidates (aHR:_0.100.24_0.55, P = .001). Accepting an OLD offer provided substantial long‐term survival benefit compared to waiting for a better organ offer, notably among candidates with MELD 35‐40. Providers should consider these benefits as they evaluate OLD graft offers.     

Utilization of high donor sequence number grafts in cardiac transplantation

Donor sequence number (DSN) represents the number of candidates to whom a graft was offered and declined prior to acceptance for transplantation. We sought to investigate the outcomes of patients receiving high DSN grafts. Consecutive isolated adult cardiac transplantations performed at a single‐center were reviewed. Recipients were grouped into standard (≤75th percentile) DSN and high (>75th percentile) DSN. A previously validated donor risk index was used to quantify the risk associated with donor grafts, and recipient outcomes were assessed. Overall, 254 patients were included: 194 standard DSN (range 1‐79) and 60 high DSN (range 82‐1723). High DSN grafts were harvested at greater distance (P < .001) with increased ischemia time (P < .001), resulting in a modest increase in donor risk index (1 point median difference, P = .014). High DSN recipients were less frequently listed as UNOS status 1A (P < .001). Despite a nonsignificant trend toward increased in‐hospital/30‐day mortality in high DSN recipients, there were no differences in primary graft dysfunction or 1‐year survival (high DSN 89% vs standard DSN 88%, P = .82). After adjustment for risk factors, high DSN was not associated with increased 1‐year mortality (hazard ratio 1.18, 95%‐CI 0.54‐2.58, P = .68).     

Elevated HbA1c in donor organs from patients without a diagnosis of diabetes portends worse liver allograft survival

Recipients of liver allografts from diabetic donors have decreased graft survival. However, limited data exist on the effects of donor HbA1c. We hypothesized that allografts from nondiabetic donors with elevated HbA1c would be associated with decreased survival. Liver transplant recipients from the UNOS database from nondiabetic donors were stratified into two groups: euglycemic (HbA1c<6.5) and hyperglycemic (HbA1c≥6.5). Propensity score matching (10:1) was used to adjust for donor and recipient characteristics. Kaplan‐Meier analysis was used to assess survival. Donors of hyperglycemic allografts were older (49 vs 36, P<.001), were more likely to be non‐white, had a higher BMI (29.8 vs 26.2, P<.001), were more likely to engage in heavy cigarette use (1.5% vs 1.3%, P=.004), had higher serum creatinine levels (1.3 vs 1.0, P=.002), and were more likely to be an expanded‐criteria donor (35.8% vs 14.4%, P<.001). After propensity matching to account for these differences, allograft survival was significantly decreased in the recipients of hyperglycemic allografts (P=.049), and patient survival showed a trend toward reduction (P=.082). These findings suggest that HbA1c may be a simple and inexpensive test with potential utility for better organ risk stratification.     

The landscape of international living kidney donation in the United States

In the United States, kidney donation from international (noncitizen/nonresident) living kidney donors (LKDs) is permitted; however, given the heterogeneity of healthcare systems, concerns remain regarding the international LKD practice and recipient outcomes. We studied a US cohort of 102 315 LKD transplants from 2000‐2016, including 2088 international LKDs, as reported to the Organ Procurement and Transplantation Network. International LKDs were more tightly clustered among a small number of centers than domestic LKDs (Gini coefficient 0.76 vs 0.58, P < .001). Compared with domestic LKDs, international LKDs were more often young, male, Hispanic or Asian, and biologically related to their recipient (P < .001). Policy‐compliant donor follow‐up was substantially lower for international LKDs at 6, 12, and 24 months postnephrectomy (2015 cohort: 45%, 33%, 36% vs 76%, 71%, 70% for domestic LKDs, P < .001). Among international LKDs, Hispanic (aOR = _0.230.36_0.56, P < .001) and biologically related (aOR = _0.390.59_0.89, P < .01) donors were more compliant in donor follow‐up than white and unrelated donors. Recipients of international living donor kidney transplant (LDKT) had similar graft failure (aHR = _0.780.89_1.02, P = .1) but lower mortality (aHR = _0.530.62_0.72, P < .001) compared with the recipients of domestic LDKT after adjusting for recipient, transplant, and donor factors. International LKDs may provide an alternative opportunity for living donation. However, efforts to improve international LKD follow‐up and engagement are warranted.     

Outcomes of donation after circulatory death kidneys undergoing hypothermic machine perfusion following static cold storage: A UK population‐based cohort study

Evidence is currently lacking regarding the outcomes of kidneys undergoing hypothermic machine perfusion (HMP) in patients in the United Kingdom. Using the National Health Service Blood and Transplant database, the authors compared outcomes for recipients of single‐organ donation after circulatory death (DCD) kidneys preserved with HMP with those preserved using only static cold storage (SCS). Between 2007 and 2015, HMP was used in 19.1% (864/4,529) of kidneys. Rates of delayed graft function (DGF) were significantly lower in organs preserved with HMP than for organs preserved with SCS (34.2% vs 42.0%, P < .001), despite a slightly longer cold ischemic time (median: 14.8 vs 14.1 hours, P < .001). Multivariable analysis found the effect of preservation modality to remain significant, with HMP organs having a significantly lower rate of DGF (odds ratio 0.65, 95% confidence interval 0.53‐0.80, P < .001) and significantly shorter times to DGF resolution (average: 6.1 vs 7.4 days, P = .003) than SCS organs. The patient (P = .313) and graft (P = .263) survival rates were similar in the 2 preservation groups. HMP was associated with a marginal functional benefit in 1‐year creatinine values (P = .044), with adjusted averages of 1.36 mg/dL (HMP) versus 1.40 mg/dL (SCS). This study supports the use of HMP and aids decision‐making over its instigation, which may improve short‐term patient outcomes.     

Comparative survival of elderly renal transplant recipients with a living donor versus a deceased donor: A retrospective single center observational study

Increasing numbers of elderly (≥65 years) patients are listed for kidney transplantation. This study compares the survival outcome between living (LDK), regularly allocated (ETKAS), and Eurotransplant Senior Program (ESP) donor kidneys in elderly recipients. This is a single-center retrospective cohort study of elderly kidney transplant recipients transplanted between 2005 and 2017. Primary outcome measures were nondeath-censored graft, death-censored graft, and patient survival. In total, 348 patients were transplanted, 109 recipients (31.3%) received an LDK, 100 (28.7%) an ETKAS, and 139 (40%) an ESP kidney. 62.5% were male, and median age was 68 years. LDK recipients had significantly better 5-year nondeath-censored graft survival compared with ETKAS and ESP (resp. 71.0% vs. 66.1% vs. 55.6%, P = 0.047). Death-censored graft survival after 1 year was significantly better in LDK recipients (99.1%) (ETKAS 90.8%; ESP 87.7%, P < 0.001). After 5 years, the difference remained significant (P < 0.001) with little additional graft loss (97.7% vs. 88.1% vs. 85.6). There was no significant difference in patient survival after 5 years (71.7% vs. 67.4% vs 61.9%, P = 0.480). In elderly recipients, the patient survival benefits of an LDK are limited, but there is decreased death-censored graft loss for LDK recipients. Nevertheless, graft survival in ETKAS and ESP remains satisfactory.     

Impact of the kidney allocation system on young pediatric recipients

The kidney allocation system (KAS) altered pediatric candidate prioritization. We determined KAS's impact on pediatric kidney recipients by examining delayed graft function (DGF) rates from 2010 to 2016. A propensity score‐matched pediatric recipients pre‐ and post‐KAS. A semiparametric decomposition analysis estimated the contributions of KAS‐related changes in donor characteristics and dialysis time on DGF rate. The unadjusted odds of DGF were 69% higher post‐KAS for young (<10 years at listing) recipients (N = 1153, P = .02) but were not significantly increased for older pediatric (10‐17 years at listing) recipients (N = 2624, P = .48). Post‐KAS, young recipients received significantly fewer pediatric (<18 years) donor kidneys (21% vs 32%, P < .01) and had longer median pretransplant dialysis time (603 vs 435 days, P < .01). After propensity score matching, post‐KAS status increased the odds of DGF in young recipients 71% (OR 1.71, 95% CI 1.01‐2.46). In decomposition analysis, 24% of the higher DGF rate post‐KAS was attributable to donor characteristics and 19% to increased recipient dialysis time. In a confirmatory survival analysis, DGF was associated with a 2.2 times higher risk of graft failure (aHR2.28, 95% CI 1.46‐3.54). In conclusion, KAS may lead to worse graft survival outcomes in children. Allocation changes should be considered.