Faculty Bibliography

Stakeholders have expressed concerns regarding decreased deceased donor kidney transplant (DDKT) rates for pediatric candidates under the Kidney Allocation System (KAS). To better understand what might be driving this, we studied Scientific Registry of Transplant Recipients kidney offer data for 3642 pediatric (age <18 years) kidney-only transplant candidates between December 31, 2012 to December 3, 2014 (pre-KAS) and December 4, 2014 to January 6, 2017 (post-KAS). We used negative binomial regression and multilevel logistic regression to compare offer and acceptance rates pre- and post-KAS. We stratified by donor age (<18, 18-34, and 35+ years) and KDPI (<35% and ≥35%) to reflect differing allocation prioritization pre-KAS and post-KAS. As might be expected from prioritization changes, post-KAS candidates were less likely to receive offers for donors 18-34 years old with KDPI ≥ 35% (adjusted incidence rate ratio [aIRR]: _0.18 0.21_0.25 , P < .001), and more likely to receive offers for donors 18-34 years old and KDPI < 35% (aIRR: _1.12 1.20_1.29 , P < .001). However, offer acceptance practices also changed post-KAS: kidneys from donors 18-34 years old and KDPI < 35% were 23% less likely to be accepted post-KAS (adjusted odds ratio: _0.61 0.77_0.98 , P = .03). Using kidneys from donors 18-34 years old with KDPI < 35% post-KAS to the same extent they were used pre-KAS might be an effective strategy to mitigate any decrease in DDKT rates for pediatric candidates.

Background/UNASSIGNED:The early effects of coronavirus disease 2019 (COVID-19) on transplantation are dramatic: >75% of kidney and liver programs are either suspended or operating under major restrictions. To resume transplantation, it is important to understand the prevalence of COVID-19 among transplant recipients, donors, and healthcare workers (HCWs) and its associated mortality. Methods/UNASSIGNED:To investigate this, we studied severe acute respiratory syndrome coronavirus 2 diagnostic test results among patients with end-stage renal disease or kidney transplants from the Johns Hopkins Health System (n = 235), and screening test results from deceased donors from the Southwest Transplant Alliance Organ Procurement Organization (n = 27), and donors, candidates, and HCWs from the National Kidney Registry and Viracor-Eurofins (n = 253) between February 23 and April 15, 2020. Results/UNASSIGNED:We found low rates of COVID-19 among donors and HCWs (0%-1%) who were screened, higher rates of diagnostic tests among patients with end-stage renal disease or kidney transplant (17%-20%), and considerable mortality (7%-13%) among those who tested positive. Conclusions/UNASSIGNED:These findings suggest the threat of COVID-19 for the transplant population is significant and ongoing data collection and reporting is critical to inform transplant practices during and after the pandemic.

Background/UNASSIGNED:Caring for dialysis patients is difficult, and this burden often falls on a spouse or cohabiting partner (henceforth referred to as caregiver-partners). At the same time, these caregiver-partners often come forward as potential living kidney donors for their loved ones who are on dialysis (henceforth referred to as patient-partners). Caregiver-partners may experience tangible benefits to their well-being when their patient-partner undergoes transplantation, yet this is seldom formally considered when evaluating caregiver-partners as potential donors. Methods/UNASSIGNED:To quantify these potential benefits, we surveyed caregiver-partners of dialysis patients and kidney transplant (KT) recipients (N = 99) at KT evaluation or post-KT. Using validated tools, we assessed relationship satisfaction and caregiver burden before or after their patient-partner's dialysis initiation and before or after their patient-partner's KT. Results/UNASSIGNED: = 0.3). Conclusions/UNASSIGNED:These benefits in caregiver burden and relationship quality support special consideration for spouses and partners in risk-assessment of potential kidney donors, particularly those with risk profiles slightly exceeding center thresholds.

COVID-19 is a novel, rapidly changing pandemic: consequently, evidence-based recommendations in solid organ transplantation (SOT) remain challenging and unclear. To understand the impact on transplant activity across the United States, and center-level variation in testing, clinical practice, and policies, we conducted a national survey between March 24, 2020 and March 31, 2020 and linked responses to the COVID-19 incidence map. Response rate was a very high 79.3%, reflecting a strong national priority to better understand COVID-19. Complete suspension of live donor kidney transplantation was reported by 71.8% and live donor liver by 67.7%. While complete suspension of deceased donor transplantation was less frequent, some restrictions to deceased donor kidney transplantation were reported by 84.0% and deceased donor liver by 73.3%; more stringent restrictions were associated with higher regional incidence of COVID-19. Shortage of COVID-19 tests was reported by 42.5%. Respondents reported a total of 148 COVID-19 recipients from <1 to >10 years posttransplant: 69.6% were kidney recipients, and 25.0% were critically ill. Hydroxychloroquine (HCQ) was used by 78.1% of respondents; azithromycin by 46.9%; tocilizumab by 31.3%, and remdesivir by 25.0%. There is wide heterogeneity in center-level response across the United States; ongoing national data collection, expert discussion, and clinical studies are critical to informing evidence-based practices.

BACKGROUND:There is concern in the transplant community that outcomes for the most highly sensitized recipients might be poor under Kidney Allocation System (KAS) high prioritization. METHODS:To study this, we compared posttransplant outcomes of 525 pre-KAS (December 4, 2009, to December 3, 2014) calculated panel-reactive antibodies (cPRA)-100% recipients to 3026 post-KAS (December 4, 2014, to December 3, 2017) cPRA-100% recipients using SRTR data. We compared mortality and death-censored graft survival using Cox regression, acute rejection, and delayed graft function (DGF) using logistic regression, and length of stay (LOS) using negative binomial regression. RESULTS:Compared with pre-KAS recipients, post-KAS recipients were allocated kidneys with lower Kidney Donor Profile Index (median 30% versus 35%, P < 0.001) but longer cold ischemic time (CIT) (median 21.0 h versus 18.6 h, P < 0.001). Compared with pre-KAS cPRA-100% recipients, those post-KAS had higher 3-year patient survival (93.6% versus 91.4%, P = 0.04) and 3-year death-censored graft survival (93.7% versus 90.6%, P = 0.005). The incidence of DGF (29.3% versus 29.2%, P = 0.9), acute rejection (11.2% versus 11.7%, P = 0.8), and median LOS (5 d versus 5d, P = 0.2) were similar between pre-KAS and post-KAS recipients. After accounting for secular trends and adjusting for recipient characteristics, post-KAS recipients had no difference in mortality (adjusted hazard ratio [aHR]: 0.861.623.06, P = 0.1), death-censored graft failure (aHR: 0.521.001.91, P > 0.9), DGF (adjusted odds ratio [aOR]: 0.580.861.27, P = 0.4), acute rejection (aOR: 0.610.941.43, P = 0.8), and LOS (adjusted LOS ratio: 0.981.161.36, P = 0.08). CONCLUSIONS:We did not find any statistically significant worsening of outcomes for cPRA-100% recipients under KAS, although longer-term monitoring of posttransplant mortality is warranted.

BACKGROUND:Hepatitis C virus-positive (HCV+) kidney transplant (KT) recipients are at increased risks of rejection and graft failure. The optimal induction agent for this population remains controversial, particularly regarding concerns that antithymocyte globulin (ATG) might increase HCV-related complications. METHODS:Using Scientific Registry of Transplant Recipients and Medicare claims data, we studied 6780 HCV+ and 139 681 HCV- KT recipients in 1999-2016 who received ATG or interleukin-2 receptor antagonist (IL2RA) for induction. We first examined the association of recipient HCV status with receiving ATG (versus IL2RA) using multilevel logistic regression. Then, we studied the association of ATG (versus IL2RA) with KT outcomes (rejection, graft failure, and death) and hepatic complications (liver transplant registration and cirrhosis) among HCV+ recipients using logistic and Cox regression. RESULTS:HCV+ recipients were less likely to receive ATG than HCV- recipients (living donor, adjusted odds ratio [aOR] = 0.640.770.91; deceased donor, aOR = 0.710.810.92). In contrast, HCV+ recipients who received ATG were at lower risk of acute rejection compared to those who received IL2RA (1-y crude incidence = 11.6% versus 12.6%; aOR = 0.680.820.99). There was no significant difference in the risks of graft failure (adjusted hazard ratio [aHR] = 0.861.001.17), death (aHR = 0.850.951.07), liver transplant registration (aHR = 0.580.971.61), and cirrhosis (aHR = 0.730.921.16). CONCLUSIONS:Our findings suggest that ATG, as compared to IL2RA, may lower the risk of acute rejection without increasing hepatic complications in HCV+ KT recipients. Given the higher rates of acute rejection in this population, ATG appears to be safe and reasonable for HCV+ recipients.

BACKGROUND:We sought to identify factors that are associated with LOS following pediatric (<18 years) liver transplantation in order to provide personalized counseling and discharge planning for recipients and their families. METHODS:We identified 2726 infants (≤24 months) and 3210 children (>24 months) who underwent pediatric liver-only transplantation from 2002-2017 using the Scientific Registry of Transplant Recipients. We used multilevel multivariable negative binomial regression to analyze associations between LOS and recipient and donor characteristics and calculated the MLOSR to quantify heterogeneity in LOS across centers. RESULTS:) were associated with a longer LOS. The MLOSR was 1.25 in infants and 1.26 in children, meaning if an infant received a transplant at another center with a longer LOS, we would expect a 1.25-fold difference in LOS driven by center practices alone. CONCLUSIONS:While center-level practices account for substantial variation in LOS, consideration of donor and recipient factors can help clinicians provide more personalized counseling for families of pediatric liver transplant candidates.

It has been hypothesized that transplanting simultaneous pancreas kidney (SPK) grafts from donors with a history of cardiac arrest and cardiopulmonary resuscitation (CACPR) leads to inferior posttransplant outcomes due to organ hypoperfusion during cardiac arrest and mechanical trauma during resuscitation. Using Scientific Registry of Transplant Recipients data, we identified 13 095 SPK transplants from 2000-2018, of which 810 (6.2%) were from donors with a history of CACPR. After inverse probability of treatment weighting on donor and recipient characteristics, we found that 1-, 5-, and 10-year patient (CACPR: 96.4%, 89.9%, and 78.9%; non-CACPR: 96.3%, 88.9%, and 76.0%; P = .3), death-censored pancreas graft survival (CACPR: 89.3%, 82.7%, 75.0%; non-CACPR: 89.9%, 82.7%, 76.3%; P = .7), and death-censored kidney graft survival (CACPR: 97.0%, 89.5%, 78.2%; non-CACPR: 96.9.9%, 88.7%, 80.0%; P = .4) were comparable between the two groups. There were no differences in the risk of pancreatitis (CACPR: 2.9%, non-CACPR: 2.4%; weighted OR = _0.74 1.22 _2.02 ; P = .4), anastomotic leak (CACPR: 1.6%, non-CACPR: 2.0%; weighted OR = _0.54 1.02 _1.93 ; P > .9), or median length of hospital stay (CACPR: 8 days, non-CACPR: 9 days; P = .6) for recipients of CACPR vs non-CACPR donors. Our findings suggest that CACPR donors could be used to expand the SPK donor pool without compromising short- or long-term outcomes.

Purpose: In heart transplantation (HT), antibodies directed against Angiotensin II type 1 receptor (AT1RAb) have been associated with antibody-mediated rejection (AMR), acute cellular rejection (ACR), and microvasculopathy. The effect of AT1RAb detected pre-HT on immediate post-HT allograft injury remains poorly defined. In this study, we leverage a validated and sensitive blood based biomarker for allograft injury, donor-derived cell-free DNA (ddcfDNA), to examine the association of pre-HT AT1RAb to post-HT allograft injury.
Method(s): AT1RAb testing was performed on pretransplant plasma from HT recipients in the Genomic Research Alliance for Transplantation (GRAfT) multicenter, prospective cohort study, using a quantitative ELISA (One Lambda, ThermoFisher). After HT, serial plasma samples were collected and used to quantitate %ddcfDNA by shotgun sequencing. AT1RAb concentration (units/ml) was used to categorize patients as AT1RAb<30 (n=32) or AT1RA>30 (n=17). A mixed linear model was used to examine post-HT %ddcfDNA trajectories across AT1RAb groups. Histopathology slides were read by a consensus of pathologists to define AMR using ISHLT criteria.
Result(s): Age, gender and clinical features were similar between AT1RAb<30 and AT1RA>30 groups. AT1RAb>30 had a greater proportion of White recipients compared to AT1RAb<30 (59% versus 38%; p = 0.003). While %ddcfDNA on posttransplant Day 1 were similar between AT1RAb<30 vs AT1RAb>30 (p=0.6), in the first year post-HT, ddcfDNA declined by 87% (95% CI 79%-92%) among patients with AT1RAb<30 vs 67% (CI=34%-84%) among patients with AT1RAb>30 (p = 0.04) (Figure). AMR in the first year post-HT was more common among AT1RAb>30 than AT1RAb<30 patients (18% vs 3%, p=0.07); CMR was comparable in each group (41% vs 24%, p=0.2).
Conclusion(s): Preliminary analysis of this heart transplant cohort suggest that high pre-HT AT1RAb is associated with increased early post-HT allograft injury.
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Importance:Living kidney donation is associated with increased long-term risk of end-stage renal disease (ESRD). An early postdonation marker of ESRD risk could improve postdonation risk assessment and counseling for kidney donors and allow early intervention for donors at increased risk. Objective:To determine the association between renal function in the first 6 months postdonation and subsequent risk of ESRD in kidney donors. Design, Setting, and Participants:This secondary analysis of a prospective national cohort uses a population-based registry of all living kidney donors in the United States between October 26, 1999, and January 1, 2018, with follow-up through December 31, 2018. All kidney donors who had donated in the date range and had serum creatinine measured at 6 months (±3 months) postdonation were included. Exposures:Renal function as measured by estimated glomerular filtration rate 6 months after donation (eGFR6). Main Outcomes and Measures:End-stage renal disease, ascertained via linkage to Centers for Medicare & Medicaid Services data. Results:A total of 71 468 living kidney donors were included (of 109 065 total donors over this period). Their median (interquartile range) eGFR6 was 63 (54-74) mL/min/1.73 m2. Cumulative incidence of ESRD at 15 years postdonation ranged from 11.7 donors per 10 000 donors with eGFR6 values greater than 70 mL/min/1.73 m2 to 33.1 donors per 10 000 donors with eGFR6 values of 50 mL/min/1.73 m2 or less. Adjusting for age, race, sex, body mass index, and biological relationship, every 10 mL/min/1.73 m2 reduction in eGFR6 was associated with a 28% increased risk of ESRD (adjusted hazard ratio, 1.28 [95% CI, 1.06-1.54]; P = .009). The association between predonation eGFR and ESRD was not significant and was fully mediated by eGFR6 (adjusted hazard ratio, 1.00 [95% CI, 0.86-1.17]; P = .97). The postdonation eGFR value was a better marker of ESRD than eGFR decline after donation or the ratio of eGFR6 to predonation eGFR, as determined by the Akaike information criterion (in which a lower value indicates a better model fit; eGFR6, 1495.61; predonation eGFR - eGFR6, 1503.58; eGFR6 / predonation eGFR, 1502.30). Conclusions and Relevance:In this study, there was an independent association of eGFR6 with subsequent ESRD risk in living kidney donors, even after adjusting for predonation characteristics. The findings support measurement of early postdonation serum creatinine monitoring in living kidney donors, and the use of these data to help identify donors who might need more careful surveillance and early intervention.