Mary G. Bowring

A Risk Index for Living Donor Kidney Transplantation

Choosing between multiple living kidney donors, or evaluating offers in kidney paired donation, can be challenging because no metric currently exists for living donor quality. Furthermore, some deceased donor (DD) kidneys can result in better outcomes than some living donor kidneys, yet there is no way to compare them on the same scale. To better inform clinical decision‐making, we created a living kidney donor profile index (LKDPI) on the same scale as the DD KDPI, using Cox regression and adjusting for recipient characteristics. Donor age over 50 (hazard ratio [HR] per 10 years = 1.151.241.33), elevated BMI (HR per 10 units = 1.011.091.16), African‐American race (HR = 1.151.251.37), cigarette use (HR = 1.091.161.23), as well as ABO incompatibility (HR = 1.031.271.58), HLA B (HR = 1.031.081.14) mismatches, and DR (HR = 1.041.091.15) mismatches were associated with greater risk of graft loss after living donor transplantation (all p < 0.05). Median (interquartile range) LKDPI score was 13 (1–27); 24.2% of donors had LKDPI < 0 (less risk than any DD kidney), and 4.4% of donors had LKDPI > 50 (more risk than the median DD kidney). The LKDPI is a useful tool for comparing living donor kidneys to each other and to deceased donor kidneys.

Changes in Utilization and Discard of Hepatitis C–Infected Donor Livers in the Recent Era

The impact of interferon (IFN)‐free direct‐acting antiviral (DAA) hepatitis C virus (HCV) treatments on utilization and outcomes associated with HCV‐positive deceased donor liver transplantation (DDLT) is largely unknown. Using the Scientific Registry of Transplant Recipients, we identified 25 566 HCV‐positive DDLT recipients from 2005 to 2015 and compared practices according to the introduction of DAA therapies using modified Poisson regression. The proportion of HCV‐positive recipients who received HCV‐positive livers increased from 6.9% in 2010 to 16.9% in 2015. HCV‐positive recipients were 61% more likely to receive an HCV‐positive liver after 2010 (early DAA/IFN era) (aRR:1.451.611.79, p < 0.001) and almost three times more likely to receive one after 2013 (IFN‐free DAA era) (aRR:2.582.853.16, p < 0.001). Compared to HCV‐negative livers, HCV‐positive livers were 3 times more likely to be discarded from 2005 to 2010 (aRR:2.692.993.34, p < 0.001), 2.2 times more likely after 2010 (aRR:1.802.162.58, p < 0.001) and 1.7 times more likely after 2013 (aRR:1.371.682.04, p < 0.001). Donor HCV status was not associated with increased risk of all‐cause graft loss (p = 0.1), and this did not change over time (p = 0.8). Use of HCV‐positive livers has increased dramatically, coinciding with the advent of DAAs. However, the discard rate remains nearly double that of HCV‐negative livers. Further optimization of HCV‐positive liver utilization is necessary to improve access for all candidates.

Direct-Acting Antiviral Prophylaxis in Kidney Transplantation From Hepatitis C Virus–Infected Donors to Noninfected Recipients: An Open-Label Nonrandomized Trial

More than 420000 persons in the United States require hemodialysis for end-stage kidney disease (1). These patients face a high mortality rate: 169 per 1000 patient-years, compared with 30 per 1000 patient-years for transplant recipients (1). Furthermore, the survival benefit of kidney transplant recipients is well-established (2, 3) and persists even with the use of kidneys from older donors with certain medical conditions (4). However, a severe shortage of transplant organs exists. Depending on geography, waiting times for kidney transplantation may be as long as 10 years, and it is estimated that more than 50% of candidates on the waiting list will die before receiving a transplant (5, 6). Thus, expansion of the donor pool would have a significant public health benefit. Kidneys from deceased donors with hepatitis C virus (HCV) infection are underutilized. In the United States, between 2005 and 2014, a total of 2698 kidneys recovered from HCV-infected donors intended for transplantation were discarded (7). A national study demonstrated that kidneys from HCV-infected donors are 2.9 times more likely to be discarded than kidneys of the same quality from nonHCV-infected donors, despite providing a survival benefit compared with remaining on dialysis (8). The excess discarding may partly result from the lack of HCV-infected transplant candidates as well as the increase in deceased donors with HCV infection, probably because of the epidemic of drug overdose deaths (911). Donors with HCV generally are young and have few other medical comorbid conditions, and kidney transplantation outcomes from these donors have been excellent (12). In the past, transmission of HCV from donor to recipient was a serious concern. However, the landscape of HCV changed in 2013 with the introduction of direct-acting antiviral (DAA) agents with high cure rates, even in kidney transplant recipients (1317). In 2015, the once-daily, fixed-dose combination of the NS3/4A protease inhibitor grazoprevir (GZR) and the NS5A inhibitor elbasvir (EBR) was approved for use in persons with impaired renal function and HCV genotype 1 and 4 infection (18). For genotype 2 and 3 infection, the NS5B inihibitor sofosbuvir (SOF) is highly active (19). Additional trials demonstrated the efficacy of GZREBR combined with SOF for genotype 3 infection (20, 21). Because of these developments, interest has been growing in the use of organs from HCV-infected donors for transplantation to nonHCV-infected recipients (that is, HCV D+/Rtransplantation) (7, 22, 23). The objective of our study was to explore a strategy to prevent HCV infection in noninfected recipients of kidneys from HCV-infected donors. As such, we investigated the feasibility and tolerability of GZREBR with or without SOF prophylaxis in an open-label single-center trial at Johns Hopkins University (EXPANDER [Exploring Renal Transplants Using Hepatitis C Infected Donors for HCV-Negative Recipients]; ClinicalTrials.gov: NCT02781649). Supplement. Study Protocol Methods Study Population Kidney transplant candidates on the deceased-donor transplant waiting list at Johns Hopkins Hospital (JHH) aged at least 50 years were eligible if they were receiving hemodialysis or peritoneal dialysis or had had a glomerular filtration rate (GFR) less than 15 mL/min/1.73 m2 for at least 90 days. Candidates had to have negative results on HCV antibody and RNA testing and no HCV risk factors besides receiving hemodialysis. Eligible candidates could not have any living donors available and must not have received a solid organ transplant previously. Candidates could not be listed for multiorgan transplantation or a blood typeincompatible transplantation. Candidates were ineligible if they had HIV infection; active hepatitis B virus infection; cirrhosis; or a history of liver disease, such as nonalcoholic steatohepatitis. Study Design After providing written informed consent, participants were listed with the United Network for Organ Sharing (UNOS) with the status of willing to accept an HCV+ organ. The JHH transplant team then received offers from UNOS of kidneys from HCV-infected donors according to standard allocation policies. Eligible donors had to be between 13 and 50 years of age and have a positive result on a qualitative HCV nucleic acid test performed by the local Organ Procurement Organization (OPO) in accordance with standard UNOS policy. Other donor inclusion criteria were terminal serum creatinine level less than 265 mol/L (3 mg/dL), projected cold ischemia time less than 36 hours, and preimplantation renal biopsy showing no evidence of chronic histologic changes in the donor kidney. The OPOs performed donor HCV antibody and qualitative HCV nucleic acid testing using a U.S. Food and Drug Administration (FDA)-approved assay in accordance with UNOS-mandated deceased-donor testing. The results were available at the time of organ offer. Donor serum HCV RNA quantification and genotyping were performed in parallel with the transplantation, and results were available within 7 days of the procedure. Hepatitis C virus RNA was quantified by using the COBAS AmpliPrep/COBAS TaqMan HCV Test, version 2.0 (Roche Molecular Systems), or cobas HCV for cobas 6800 (Roche Molecular Systems) (lower limit of quantification [LLOQ] for both tests, 15 IU/mL). Hepatitis C virus genotyping was performed with a line probe assay (Quest Diagnostics), with reflex testing for NS5A resistance-associated substitutions (RASs) at positions 28, 30, 31, and 93 if genotype 1a was identified. Grazoprevir, 100 mg, and EBR, 50 mg, were administered orally to participants while they waited to go to the operating room for the donor kidneys. Postexposure prophylaxis after HCV D+/Rtransplantation varied according to the results of donor HCV testing. For recipients of kidneys from donors infected with HCV genotype 1a without NS5a RASs, genotype 1b, or genotype 4, GZREBR treatment was continued daily for 12 weeks. For recipients of organs from donors with genotype 1a infection with NS5a RASs, ribavirin was added to the GZREBR regimen for 16 weeks. For recipients of kidneys from donors infected with genotype 2 or 3, SOF, 400 mg/d, was added to the GZREBR regimen and continued for 12 weeks from the start of SOF treatment. If the donors genotype could not be determined because of insufficient viral load, treatment with GZREBR alone was continued for 12 weeks. Recipients were given induction immunosuppression with intravenous methylprednisolone and intravenous rabbit antithymocyte globulin, followed by maintenance immunosuppression therapy consisting of tacrolimus, mycophenolate mofetil, and prednisone. Prophylaxis for other posttransplantation infections included trimethoprimsulfamethoxazole for Pneumocystis jirovecii pneumonia, valganciclovir for cytomegalovirus infection in recipients who had cytomegalovirus seropositivity or received a kidney from a donor with cytomegalovirus seropositivity, and clotrimazole for oral candidiasis. Recipient Clinical Assessments Other on-treatment assessments, performed at 1- to 4-week intervals, included physical examination, review of medications and safety assessments, and evaluation of renal and liver function and hemoglobin levels. Glomerular filtration rate was calculated by using the Chronic Kidney Disease Epidemiology Collaboration equation (24). Posttreatment evaluation included safety assessments through the 12th week after treatment. Recipient Virologic Assessment and Treatment Response Recipient serum HCV RNA was measured with the COBAS Ampliprep TaqMan HCV Test, version 2.0, on day 0 before transplantation; on postoperative day 1; and at treatment weeks 1, 2, 3, 4, 8, and 12 through the end of treatment. The LLOQ was 15 IU/mL. After treatment, serum HCV RNA was measured at follow-up weeks 2, 4, 8, and 12. For recipients of kidneys from donors with HCV genotype 2 or 3, treatment week corresponds to week of treatment with the 3-drug combination (GZREBR + SOF). Recipient Immunologic Assessments Recipient HCV antibody testing was performed with the Advia Centaur system (Siemens) at baseline and follow-up week 12. Hepatitis C virusspecific CD8+ T-cell responses were evaluated by interferon (IFN)- enzyme-linked immunospot assay using a matrix of 73 peptides corresponding to previously described optimal cytotoxic T-lymphocyte epitopes, predominantly for genotype 1, with each peptide pool containing 7 to 12 peptides (25). In brief, peripheral blood mononuclear cells were separated by using the FicollHypaque method. Enzyme-linked immunospot plates were coated with 5 g/mL of anti-human IFN- monoclonal antibody (mAb; Mabtech) and kept at 4C overnight. The plates were washed and blocked with 10% fetal bovine serum in Roswell Park Memorial Institute 1640 medium for 2 hours at 37C, then 2105 peripheral blood mononuclear cells were plated with 1 of 22 HCV peptide pools or control peptides against cytomegalovirus, EpsteinBarr virus, and influenza at a final concentration of 10 g/mL. The plates were incubated at 37C for 15 to 20 hours in a humidified incubator at 5% carbon dioxide. The following day, the plates were washed 7 times with phosphate buffered saline with 0.05% Tween 20 (Sigma-Aldrich). Detection antibody (biotinylated mouse anti-human IFN- mAb [Mabtech]) was added at a final concentration of 0.5 g/mL, and the plates were kept at room temperature for 2 hours. They were then washed 4 times as described earlier, alkaline phosphataseconjugated antibiotin mAb (Vector Laboratories) was added, and they were kept at room temperature for 2 hours. The plates were developed with NBT/BCIP Substrate Solution (ThermoFisher Scientific), and spots were counted by using the AID iSpot Spectrum (Advanced Imaging Devices). Only pools in which HCV-specific responses were greater than 50 spot-forming cells per million peripheral blood mononuclear cells were considered positive. Statistical Analysis The primary safety end point was the incide

Landscape of Deceased Donors Labeled Increased Risk for Disease Transmission Under New Guidelines

Deceased donors are labeled increased risk for disease transmission (IRD) if they meet certain criteria. New PHS guidelines were recently implemented; the impact of these changes remains unknown. We aimed to quantify the impact of the new guidelines on the proportion of deceased donors labeled IRD, as well as demographic and clinical characteristics. We used Poisson regression with an interaction term for era (new vs. old guidelines) to quantify changes. Under the new guidelines, 19.5% donors were labeled IRD, compared to 10.4%, 12.2%, and 12.3% in the 3 most recent years under the old guidelines (IRRu2009=u20091.45, pu2009<u20090.001). Increases were consistent across OPOs: 44/59 had an increase in the percent of donors labeled IRD, and 14 OPOs labeled 25% of their donors IRD under the new guidelines (vs. 5 OPOs under the old). African‐Americans were 52% more likely to be labeled IRD under the new guidelines (RRu2009=u20091.52, pu2009=u20090.01). There has been a substantial increase in donors labeled IRD under the new PHS guidelines; it is important to understand the mechanism and consequences to ensure an optimal balance of patient safety and organ utilization is achieved.

Turn down for what? Patient outcomes associated with declining increased infectious risk kidneys

Transplant candidates who accept a kidney labeled increased risk for disease transmission (IRD) accept a low risk of window period infection, yet those who decline must wait for another offer that might harbor other risks or never even come. To characterize survival benefit of accepting IRD kidneys, we used 2010‐2014 Scientific Registry of Transplant Recipients data to identify 104 998 adult transplant candidates who were offered IRD kidneys that were eventually accepted by someone; the median (interquartile range) Kidney Donor Profile Index (KDPI) of these kidneys was 30 (16‐49). We followed patients from the offer decision until death or end‐of‐study. After 5 years, only 31.0% of candidates who declined IRDs later received non‐IRD deceased donor kidney transplants; the median KDPI of these non‐IRD kidneys was 52, compared to 21 of the IRDs they had declined. After a brief risk period in the first 30 days following IRD acceptance (adjusted hazard ratio [aHR] accept vs decline: 1.222.063.49, P = .008) (absolute mortality 0.8% vs. 0.4%), those who accepted IRDs were at 33% lower risk of death 1‐6 months postdecision (aHR 0.500.670.90, P = .006), and at 48% lower risk of death beyond 6 months postdecision (aHR 0.460.520.58, P < .001). Accepting an IRD kidney was associated with substantial long‐term survival benefit; providers should consider this benefit when counseling patients on IRD offer acceptance.

The drug overdose epidemic and deceased-Donor transplantation in the United States a national registry study

Overdose deaths in the United States have nearly tripled over the past 15 years, with 52404 reported in 2015 (1, 2). Younger adults are disproportionately affected, with the highest rates among those aged 25 to 55 years in the Northeast, Midwest, and South (1, 3). At the same time, the United States has a severe shortage of organ donors for transplant, with more than 120000 patients on national waitlists but only 10281 donors in 2017 (4). Median wait times range from 5 to 7 years, and for some candidates, the risk for death while on the waitlist is greater than the chance of receiving an organ (5, 6). Although almost all transplants provide a survival benefit, optimal outcomes are observed with organs from young trauma-death donors (TDDs) who donate after brain death (79). Overdose-death donors (ODDs) often experience anoxic brain death and have few comorbidities; thus, their organs could have excellent recipient outcomes, similar to TDD organs. However, ODDs might be designated as increasedinfectious risk donors (IRDs) due to behaviors that increase risk for HIV, hepatitis B virus (HBV), or hepatitis C virus (HCV) infection (10, 11). The IRD label might reduce use of ODD organs because it is associated with organ discard (surgical recovery without subsequent use for transplant) (12). Moreover, ODDs are increasingly positive for HCV antibodies (10, 11), and inferior outcomes might be expected due to HCV infection (1316). Finally, concerns that illicit drug use compromises organ quality might exist; for example, injection drug use is associated with lung granulomatosis (17). To inform provider and patient decision making with regard to ODD transplants, we used national registry data to examine posttransplant outcomes and organ discard associated with ODDs compared with TDDs and medical-death donors (MDDs). Methods Data Sources This study used data from the Scientific Registry of Transplant Recipients (SRTR) external release (available September 2017). The SRTR data system includes data on all donors, waitlisted candidates, and transplant recipients in the United States, submitted by the members of the Organ Procurement and Transplantation Network (OPTN). The Health Resources and Services Administration, United States Department of Health and Human Services, provides oversight to the activities of the OPTN and SRTR contractors. We also used data from the Centers for Disease Control and Prevention (CDC) Multiple Cause of Death database, which contains data provided by the 57 vital statistics jurisdictions through the Vital Statistics Cooperative Program (18). This study used deidentified data and was exempted by the Johns Hopkins School of Medicine Institutional Review Board (NA_00042871). Study Population We identified 337934 adult patients from 297 transplant centers who received a transplant from a deceased donor between 1 January 2000 and 1 September 2017 (177522 kidneys, 97670 livers, 35710 hearts, and 27032 lungs). Recipients missing information on donor mechanism of death (0.01% [n= 36]) were excluded. Categorization of Donor Type The primary exposure was donor mechanism of death, categorized as overdose (mechanism reported as drug intoxication), trauma (mechanism reported as blunt injury, drowning, gunshot, stab wound, asphyxiation, seizure, electric shock, or sudden infant death syndrome), or medical (mechanism reported as intracranial hemorrhage, stroke, myocardial infarction, natural causes, or other). Ascertainment of Overdose Death Rates To compare state overdose death rates with donation rates of ODDs, we compiled annual age-adjusted rates of overdose death from CDC Multiple Cause of Death data from 2000 to 2016. Overdose deaths were identified using CDC cause-of-death codes (X40 to X44, X60 to X64, X85, and Y10 to Y14) (1). Characterization of ODDs To characterize ODDs, we identified 138565 deceased donors with at least 1 organ recovered between 1 January 2000 and 1 September 2017. We report characteristics by donor type (ODD, TDD, or MDD). To determine state and census region of donors, we used donor hospital and residential ZIP codes; these were unavailable for 2739 (1.98%) donors. Statistical Analysis Model Specification for Analyses of Posttransplant Outcomes To compare posttransplant outcomes among recipients of ODD, TDD, and MDD organs, we used a 2-step propensity scoreweighted approach to estimate standardized differences in 5-year outcomes (19). Time-to-event outcomes were death-censored graft failure (defined as retransplant, dialysis [for kidney transplants], or graft failure, with censoring for mortality) and mortality (without censoring for graft failure). Five-year death-censored graft survival and patient survival are reported. Mortality data were obtained via linkage to the Social Security Death Master File, which has a reporting delay; thus, recipients were administratively censored on 28 February 2017. First, ODD, TDD, or MDD organ recipients were standardized across potential confounders by using multinomial logistic regression models, with donor type as the dependent variable and recipient and donor factors as independent variables. Variable selection was based on SRTR risk adjustment models (20). From the regression results, we derived the probability of having received an ODD organ and calculated inverse probability weights (IPWs) based on the recipients vector of covariates. Separate models were built for kidney, liver, heart, and lung transplants. Model variables and missingness are shown in Appendix Table 1. For variables missing fewer than 1% of values, complete-case adjustment was used, and for those missing more than 1%, a missing indicator was included in the initial step of the IPW standardization. Thus, ODD, TDD, and MDD organ recipients were balanced across known and unknown values before outcome measurement (21). Second, we estimated weighted (standardized) 5-year patient and graft survival and standardized risk differences (sRDs) (22, 23). The 95% CIs around the standardized survival rates and risk differences were empirically derived using bootstrap methods (200 iterations per organ). Recipients of multiple organs (n= 16452) were included in initial counts of ODD, TDD, and MDD transplants but were excluded from posttransplant analyses because they are clinically distinct from recipients of single organs. Appendix Table 1. Variables Included in Each Posttransplant Outcomes Standardization Model and Respective Missingness* Discard of Organs From ODDs To characterize discard of ODD organs (surgical recovery of the organ without transplant), we identified 187276 kidneys, 87947 livers, 32144 hearts, and 24598 lungs recovered from donors between 1 January 2005 (when key donor characteristics became available) and 1 September 2017. To address confounding, we used a 2-step IPW approach as described earlier. We built multinomial logistic regression models with donor type as the dependent variable and donor factors (age, sex, race, body mass index, diabetes, hypertension, donation after circulatory death, creatinine level >133 mol/L [>1.5 mg/dL], and calendar year of organ recovery) as independent variables. We derived the probability of being an ODD and calculated IPWs based on the donors vector of covariates. Weights were applied to logistic regression models, with discard as the dependent variable and donor type as the independent variable. Standardized mean differences in covariates were visually assessed, and covariates that remained unbalanced were included in the final model. From logistic regression models, we derived standardized risk and sRDs in discard associated with ODD organs versus both TDD and MDD organs. Logistic regression models included SE adjustment for donation service areas (58 geographic regions used for organ allocation) to account for correlation among donors from the same service area. We estimated discard risk after additional standardization by donor HCV and IRD status (see Appendix Table 2). Kidney and liver models were run with standardization for HCV and IRD status, and heart and lung models were run with standardization for IRD status only (<1% of hearts and lungs were from HCV-positive donors). Donors with missing values for diabetes (0.5%), hypertension (0.4%), HCV status (0.1%), IRD status (0.2%), or body mass index (0.3%) were excluded. Appendix Table 2. U.S. Public Health Service Behavioral Criteria for Donors at Increased Risk for Recent HIV, HBV, or HCV Infection Sensitivity Analysis To address confounding by variation across transplant centers, we performed a sensitivity analysis in which we estimated the standardized hazard ratio of mortality or graft loss associated with ODD organs, using Cox regression with and without stratification by center. To characterize potential unmeasured confounding needed to explain away our observed results, we calculated E-values for each standardized hazard ratio (24). Details are provided in the Appendix. All statistical analyses were performed using the functions mlogit and logit and the survival package stcox in Stata/SE, version 14 (StataCorp). We used a 2-sided level of 0.05 to indicate a statistically significant difference. E-values were calculated using the E-value package in R statistical software (24, 25). Role of the Funding Source This work was supported in part by the Division of Intramural Research, National Cancer Institute (grant K23CA177321-01A1), National Institute of Allergy and Infectious Diseases (grant K24DA034621), and by the National Institute of Diabetes and Digestive and Kidney Diseases (grants K24DK101828, R01AI120938, F30DK095545, R01DK111966, R01AG042504, D01DK096008, and K23DK101677). The funding sources had no role in the design, conduct, or reporting of the study or the decision to publish the manuscript. Results Increase in ODDs and Transplants We identified 7313 ODDs with at least 1 organ recovered during the study. The number of ODDs increased by 17% per year, fro

HIV+ deceased donor referrals: A national survey of organ procurement organizations

HIV‐infected (HIV+) donor organs can be transplanted into HIV+ recipients under the HIV Organ Policy Equity (HOPE) Act. Quantifying HIV+ donor referrals received by organ procurement organizations (OPOs) is critical for HOPE Act implementation.

Kidney offer acceptance at programs undergoing a Systems Improvement Agreement

In the United States, the Centers for Medicare and Medicaid Services (CMS) use Systems Improvement Agreements (SIAs) to require transplant programs repeatedly flagged for poor‐performance to improve performance or lose CMS funding for transplants. We identified 14 kidney transplant (KT) programs with SIAs and 28 KT programs without SIAs matched on waitlist volume and characterized kidney acceptance using SRTR data from 12/2006‐3/2015. We used difference‐in‐differences linear regression models to identify changes in acceptance associated with an SIA independent of program variation and trends prior to the SIA. SIA programs accepted 26.9% and 22.1% of offers pre‐ and post‐SIA, while non‐SIA programs accepted 33.9% and 44.4% of offers in matched time periods. After adjustment for donor characteristics, time‐varying waitlist volume, and secular trends, SIAs were associated with a 5.9 percentage‐point (22%) decrease in kidney acceptance (95% CI: −10.9 to −0.8, P = .03). The decrease in acceptance post‐SIA was more pronounced for KDPI 0‐40 kidneys (12.3 percentage‐point decrease, P = .007); reductions in acceptance of higher KDPI kidneys occurred pre‐SIA. Programs undergoing SIAs substantially reduced acceptance of kidney offers for waitlisted candidates. Attempts to improve posttransplant outcomes might have the unintended consequence of reducing access to transplantation as programs adopt more restrictive organ selection practices.

Fifteen-Year Trends in Pediatric Liver Transplants: Split, Whole Deceased, and Living Donor Grafts

Objective To evaluate changes in patient and graft survival for pediatric liver transplant recipients since 2002, and to determine if these outcomes vary by graft type (whole liver transplant, split liver transplant [SLT], and living donor liver transplant [LDLT]). Study design We evaluated patient and graft survival among pediatric liver‐only transplant recipients the PELD/MELD system was implemented using the Scientific Registry of Transplant Recipients. Results From 2002‐2009 to 2010‐2015, survival for SLT at 30 days improved (94% vs 98%; P < .001), and at 1 year improved for SLT (89% to 95%; P < .001) and LDLT (93% to 98%; P = .002). There was no change in survival for whole liver transplant at either 30 days (98% in both; P = .7) or 1 year (94% vs 95%; P = .2). The risk of early death with SLT was 2.14‐fold higher in 2002‐2009 (adjusted hazard ratio [aHR] vs whole liver transplant, 1.472.143.12), but this risk disappeared in 2010‐2015 (aHR, 0.651.131.96), representing a significant improvement (P = .04). Risk of late death after SLT was similar in both time periods (aHR 2002‐2009, 0.871.141.48; aHR 2010‐2015, 0.560.881.37). LDLT had similar risk of early death (aHR 2002‐2009, 0.491.032.14; aHR 2010‐2015, 0.260.742.10) and late death (aHR 2002‐2009, 0.520.831.32; aHR 2010‐2015, 0.170.441.11). Graft loss was similar for SLT (aHR, 0.931.091.28) and was actually lower for LDLT (aHR, 0.530.710.95). Conclusions In recent years, outcomes after the use of technical variant grafts are comparable with whole grafts, and may be superior for LDLT. Greater use of technical variant grafts might provide an opportunity to increase organ supply without compromising post‐transplant outcomes.

Geographic disparity in kidney transplantation under KAS

The Kidney Allocation System fundamentally altered kidney allocation, causing a substantial increase in regional and national sharing that we hypothesized might impact geographic disparities. We measured geographic disparity in deceased donor kidney transplant (DDKT) rate under KAS (6/1/2015‐12/1/2016), and compared that with pre‐KAS (6/1/2013‐12/3/2014). We modeled DSA‐level DDKT rates with multilevel Poisson regression, adjusting for allocation factors under KAS. Using the model we calculated a novel, improved metric of geographic disparity: the median incidence rate ratio (MIRR) of transplant rate, a measure of DSA‐level variation that accounts for patient casemix and is robust to outlier values. Under KAS, MIRR was 1.751.811.86 for adults, meaning that similar candidates across different DSAs have a median 1.81‐fold difference in DDKT rate. The impact of geography was greater than the impact of factors emphasized by KAS: having an EPTS score ≤20% was associated with a 1.40‐fold increase (IRR = 1.351.401.45, P < .01) and a three‐year dialysis vintage was associated with a 1.57‐fold increase (IRR = 1.561.571.59, P < .001) in transplant rate. For pediatric candidates, MIRR was even more pronounced, at 1.661.922.27. There was no change in geographic disparities with KAS (P = .3). Despite extensive changes to kidney allocation under KAS, geography remains a primary determinant of access to DDKT.