Improving Health Equity in Living Donor Kidney Transplant: Application of an Implementation Science Framework

BACKGROUND

Interventions to improve racial equity in access to living donor kidney transplants (LDKT) have focused primarily on patients, ignoring the contributions of clinicians, transplant centers, and health system factors. Obtaining access to LDKT is a complex, multi-step process involving patients, their families, clinicians, and health system functions. An implementation science framework can help elucidate multi-level barriers to achieving racial equity in LDKT and guide the implementation of interventions targeted at all levels.

METHODS

We adopted the Pragmatic Robust Implementation and Sustainability Model (PRISM), an implementation science framework for racial equity in LDKT. The purpose was to provide a guide for assessment, inform intervention design, and support planning for the implementation of interventions.

RESULTS

We applied 4 main PRISM domains to racial equity in LDKT: Organizational Characteristics, Program Components, External Environment, and Patient Characteristics. We specified elements within each domain that consider perspectives of the health system, transplant center, clinical staff, and patients.

CONCLUSION

The applied PRISM framework provides a foundation for the examination of multi-level influences across the entirety of LDKT care. Researchers, quality improvement staff, and clinicians can use the applied PRISM framework to guide the assessment of inequities, support collaborative intervention development, monitor intervention implementation, and inform resource allocation to improve equity in access to LDKT.

Incidence of Kidney Failure after Primary Organ Transplant

Key Points

Incidence of ESKD in the first year after primary organ transplant ranges from 2.4% to 3.6% and from 1.4% to 1.8% in the second year post-transplant. National data sources do not currently collect sufficiently reliable follow-up data to identify pretransplant predictors of ESKD.

Background

Careful selection of multiorgan transplant candidates is required to avoid unintended consequences to patients waiting for kidney transplant alone. The need for a safety net among heart and lung transplant recipients is unknown. The objective of this study was to quantify the incidence of kidney failure after liver, heart, or lung transplantation and identify pretransplant predictors of post-transplant kidney failure.

Methods

A retrospective cross-sectional study of adults who received liver, heart, or lung transplant between January 1, 2008, and December 31, 2018, was conducted using data from the Scientific Registry of Transplant Recipient and the United States Renal Data System. Post-transplant renal failure was defined as (1 ) new start of dialysis, (2 ) eGFR of <25 ml/min, (3 ) a new waitlisting for a kidney transplant, or (4 ) receipt of a kidney transplant.

Results

The final descriptive cohort included 53,620 liver transplant recipients, 22,042 heart transplant recipients, and 10,688 lung transplant recipients. In the first year post-transplant, the probability of ESKD was comparable among heart transplant recipients (0.036; 95% confidence interval [CI], 0.033 to 0.038) and liver transplant recipients (0.033; 95% CI, 0.031 to 0.035) but was markedly lower in lung transplant recipients (0.024; 95% CI, 0.021 to 0.027). In the second year post-transplant, the probability of ESKD was comparable among liver (0.016; 95% CI, 0.015 to 0.017), lung (0.018; 95% CI, 0.015 to 0.021), and heart transplant recipients (0.014; 95% CI, 0.013 to 0.016).

Conclusions

Candidates for thoracic transplant would likely benefit from a safety net policy similar to the one enacted in 2017 for liver transplant so as to maintain judicious patient selection for simultaneous multiorgan transplant. National data sources do not currently collect sufficiently reliable follow-up data to identify pretransplant predictors of ESKD, pointing to a need for transplant centers to consistently report kidney impairment data to national databases.

Real-world Experiences in the Transplantation of Hepatitis C-NAAT-positive Organs

Background

Hepatitis C virus (HCV) nucleic acid amplification test (NAAT)-positive donors have increased the organ pool. Direct-acting antivirals (DAAs) have led to high rates of treatment success and sustained virologic response (SVR) in recipients with donor-derived HCV infection without significant adverse effects, although variability remains in the timing and duration of antivirals.

Methods

This retrospective study analyzed all adult HCV-NAAT-negative transplant recipients who received an organ from HCV-NAAT-positive donors from November 24, 2018, to March 31, 2022, at Duke University Medical Center with protocolized delay of DAA initiation until after hospital discharge, with at least 180-d follow-up on all patients. Transplant and HCV-related outcomes were analyzed.

Results

Two hundred eleven transplants (111 kidneys, 41 livers, 34 hearts, and 25 lungs) were performed from HCV-NAAT-positive donors to HCV-NAAT-negative recipients. Ninety percent of recipients became viremic within 7 d posttransplant. Ninety-nine percent of recipients were initiated on pangenotypic DAAs in the outpatient setting a median of 52 d posttransplant, most commonly with 12-wk courses of sofosbuvir-velpatasvir (lungs) and glecaprevir-pibrentasvir (heart, kidney, and liver). Ninety-seven percent of recipients had SVR after a first-line DAA; all ultimately achieved SVR at 12 wk after subsequent treatment courses. The median peak HCV RNA for all organ systems was 2 436 512 IU/mL; the median time from antiviral to undetectable RNA was 48 d, although differences were noted between organ groups. No patient deaths or graft losses were directly attributable to HCV infection.

Conclusions

One hundred percent of transplant recipients of HCV-NAAT-positive organs ultimately developed SVR without significant adverse effects when HCV antivirals were initiated in the outpatient setting after transplant hospitalization, suggesting that this real-world treatment pathway is a viable option.

Attitudes of patients with renal disease on xenotransplantation: A systematic review

BACKGROUND

Recent years have seen major advancements in xenotransplantation: the first pig-to-human heart transplant, the development of a brain-dead recipient model for kidney xenotransplantation, and the registration of the first xenokidney clinical trial. The attitudes of patients with kidney disease or transplants on xenotransplantation and an assessment of their reservations and considerations regarding the technology are crucial to successful clinical translation and eventual widespread implementation.

METHODS

This systematic review was registered through PROSPERO (CRD42022344581) prior to initiation of the study and reported using the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. We included studies that evaluated attitudes towards and willingness to undergo xenotransplantation in patients with end-stage renal disease (ESRD), including those who had already undergone transplantation. MEDLINE (via Ovid), Embase (via Elsevier), and Web of Science (via Clarivate) were searched from database inception to July 15, 2022 by an experienced medical librarian for studies on xenotransplantation and attitudes. Abstracts and full text were screened using Covidence software and data items regarding study methodology, patient demographics, and attitudes regarding xenotransplantation were extracted using Microsoft Excel. Risk of bias assessments were performed using the Critical Appraisal Skills Programmed and National Institute of Health study quality assessment tools.

RESULTS

Of 1992 studies identified, 14 studies met the inclusion criteria. These studies were conducted across eight countries, four in the United States, for a total of 3114 patients on the kidney waitlist or with a kidney transplant. All patients were over 17 years old and 58% were male. Acceptance of a xenotransplant was assessed using surveys in 12 studies. Sixty-three percent (n = 1354) of kidney patients reported that they would accept a xenotransplant with function comparable to that of an allotransplant. Acceptance of xenografts with inferior function to allografts (15%) or as bridge organs (35%) to allotransplantation was lower. Specific concerns expressed by patients included graft function, infection, social stigma, and animal rights. Subgroup analyses showed higher acceptance in already transplanted compared to waitlist patients and white compared to Black Americans.

CONCLUSION

An understanding of patient attitudes and reservations is key to the successful execution of the first xenotransplantation clinical trials. This study compiles important factors to consider, such as patient concerns, attitudes regarding practical clinical scenarios for the use of xenotransplantation, and the impact of demographic factors on acceptance of this emerging technology.

Evaluation of Weight-Based Dose During Transition From Immediate-Release to Extended-Release Tacrolimus in Kidney Transplant Recipients

BACKGROUND

Manufacturer recommendations for conversion from immediate-release to extended-release tacrolimus, Envarsus XR®, suggests 80% of the total daily dose of the immediate-release formulation. This conversion has not consistently achieved therapeutic levels in the kidney transplant population.

OBJECTIVES

To determine if a reliable weight-based dosing strategy could be utilized to transition kidney transplant patients from immediate-release to extended-release tacrolimus. This may help establish a safe protocol to guide transition between formulations.

METHODS

Retrospective, single-center study of adult kidney transplant recipients between July 2015 and December 2018. Excluded patients received dual organs, lacked appropriately drawn tacrolimus levels, or were prescribed interacting medications. Patients were identified by querying prescriptions for extended-release tacrolimus and chart review was performed to exclude any patients without sufficient follow-up after transition.

RESULTS

30 patients who transitioned from immediate-release tacrolimus to tacrolimus XR were included in the final analysis. The median weight-based dose of tacrolimus XR that achieved a therapeutic level among the cohort was 0.158 mg/kg/day (Q1-Q3: 0.0587-0.221), which was about 80% of the original median weight-based immediate-release tacrolimus dose. Therapeutic dosing strategies were widely variable, represented by an R² of 0.33 on linear regression. There was a statistically significant difference in median weight-based dosing strategies among patients of various racial backgrounds (p = 0.0148).

CONCLUSIONS

A weight-based dose of tacrolimus XR could not reliably predict a therapeutic level among the total cohort due to the wide inter-patient variability. The median weight-based rate of conversion from immediate-release to extended-release tacrolimus was 80%.

Transcriptional responses define dysregulated immune activation in Hepatitis C (HCV)-naïve recipients of HCV-infected donor kidneys

Renal transplantation from hepatitis C (HCV) nucleic acid amplification test-positive (NAAT-positive) donors to uninfected recipients has greatly increased the organ donation pool. However, there is concern for adverse outcomes in these recipients due to dysregulated immunologic activation secondary to active inflammation from acute viremia at the time of transplantation. This includes increased rates of cytomegalovirus (CMV) DNAemia and allograft rejection. In this study, we evaluate transcriptional responses in circulating leukocytes to define the character, timing, and resolution of this immune dysregulation and assess for biomarkers of adverse outcomes in transplant patients. We enrolled 67 renal transplant recipients (30 controls, 37 HCV recipients) and performed RNA sequencing on serial samples from one, 3-, and 6-months post-transplant. CMV DNAemia and allograft rejection outcomes were measured. Least absolute shrinkage and selection operator was utilized to develop gene expression classifiers predictive of clinical outcomes. Acute HCV incited a marked transcriptomic response in circulating leukocytes of renal transplant recipients in the acute post-transplant setting, despite the presence of immunosuppression, with 109 genes significantly differentially expressed compared to controls. These HCV infection-associated genes were reflective of antiviral immune pathways and generally resolved by the 3-month timepoint after sustained viral response (SVR) for HCV. Differential gene expression was also noted from patients who developed CMV DNAemia or allograft rejection compared to those who did not, although transcriptomic classifiers could not accurately predict these outcomes, likely due to sample size and variable time-to-event. Acute HCV infection incites evidence of immune activation and canonical antiviral responses in the human host even in the presence of systemic immunosuppression. After treatment of HCV with antiviral therapy and subsequent aviremia, this immune activation resolves. Changes in gene expression patterns in circulating leukocytes are associated with some clinical outcomes, although larger studies are needed to develop accurate predictive classifiers of these events.

Abstract P341: BLOOD PRESSURE RESPONSES OF RICE DIET PROGRAM PATIENTS WITH MALIGNANT HYPERTENSION

Introduction: Prior to the availability of effective anti-hypertensive medications, patients with malignant hypertension (MH) had a poor prognosis with a median survival of ~eight months. During this era, MH patients came to Durham NC to enroll in the residential Rice Diet Program at Duke (RDP), where they were placed on a low salt (5 meq/d), low protein (5% kcal), and low fat (5% kcal) diet with no anti-hypertensive medications. Examining the medical records of >16,000 RDP patients, we identified 298 patients with MH, which we define as those with documented papilledema, no documented diabetes or pseudotumor cerebri, and with a systolic BP >170 mmHg.

Methods: Age at entry, gender, duration in RDP, BP and urine chloride (a measure of low-salt diet adherence) response were compared between those who stayed < vs. ≥ median duration (207.5 days) by Wilcoxon and within each group by paired t test. Linear regression was used to examine the association between these factors with the BP response from entry to weeks 4, 8, and 13, for those with continuous BP data during each period.

Results: BPs and urine chloride reduced significantly in both groups and the reductions were significantly greater among those with ≥ median duration ( Table ). Age at entry had no effect on BP change except at 4 weeks. Weight had no effect while male gender, higher baseline systolic BP, and greater reduction in urine chloride were all associated with a greater BP reduction (all p<0.05). This finding was consistent at all three time points.

Conclusion: A low-salt, low-protein, and low-fat diet was effective in lowering BP in those with MH. Sodium loss may be a key mechanism, but other components of the diet should also be examined.div>

Abstract P305: MACHINE LEARNING DETECTS ASSOCIATIONS BETWEEN RETINA FEATURES AND BLOOD PRESSURE STATUS IN RICE DIET PROGRAM PATIENTS

The retina provides direct evidence of target-organ damage, and in hypertension, it may reflect vascular disease status in conjunction with clinical measurement of blood pressure (BP). However, outcomes of the examination of the retina varies from one clinician to another due to various reasons. Machine learning methods have been used as a supportive tool in identifying deep retina features objectively and consistently. The Kempner Rice Diet Program, developed in the early 1940s, used a low-salt and low-protein diet intervention (Rice Diet) to treat patients with severe hypertension before effective drug treatment was available. The meticulously documented medical records of the Rice Diet Program patients and their retina photographs provide a rare opportunity to examine the association of BP trajectories and target-organ damage as reflected in the retina. We trained a deep neural network on systolic BP and funduscopic changes from the UK Biobank Project. We achieved an R 2 value of 0.36 on 16,357 validation retina images from the UK Biobank. Our model predicts BP values for specific retinal areas by producing heatmaps of higher or lower hypertensive findings. We then applied the model on 975 retina photographs of 165 patients of the Rice Diet Program. We observed a significant correlation between retina features and systolic BP (Correlation= 0.35, p = 2*10 -29 ), showing that the model generalizes to patients with hypertension and images taken under a variety of conditions between 1944-1971. We suggest that deep-learning-based predictions for retinal analysis could be useful in monitoring treatment progress and recovery from hypertension-induced target-organ damage. This assessment serves as an adjunct to point-of-care BP measurements in the subset of 165 patients. Our findings underscore the potential utility of machine learning in hypertension evaluation and treatment. Further, it may allow us to elucidate individual responses to hypertension treatment beyond BP measurement alone. Findings from this first-step analysis may promote development of more effective BP control strategies.

Center variations in patient selection for simultaneous heart-kidney transplantation

There are no established regulations governing patient selection for simultaneous heart-kidney (SHK) transplantation, creating the potential for significant center-level variations in clinical practice.

METHODS

Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) file, we examined practice trends and variations in patient selection for SHK at the center level between January 1, 2004 and March 31, 2019.

RESULTS

Overall, SHK is becoming more common with most centers performing heart transplants also performing SHK. Among patients who underwent heart transplant who were receiving dialysis, the rate of SHK varied from 22% to 86% at the center level. Among patients not on dialysis, the median estimated glomerular filtration rate (eGFR) of patients receiving SHK varied between 19 and 59 mL/min/1.73 m² . When adjusting for other factors, the odds of SHK varied 57-fold between the highest and lowest SHK performing centers.

CONCLUSION

Variation in SHK at the center level suggests the need for national guidelines around the selection of patients for SHK.

The Impact of the 2017 Kidney Allocation Policy Change on Simultaneous Liver-Kidney Utilization and Outcomes

Historically in the United States, kidneys for simultaneous liver-kidney transplantation (SLKT) candidates were allocated with livers, prioritizing SLKT recipients over much of the kidney waiting list. A 2017 change in policy delineated renal function criteria for SLKT and implemented a safety net for kidney-after-liver transplantation. We compared the use and outcomes of SLKT and kidney-after-liver transplant with the 2017 policy. United Network for Organ Sharing Standard Transplant Analysis and Research files were used to identify adults who received liver transplantations (LT) from August 10, 2007 to August 10, 2012; from August 11, 2012 to August 10, 2017; and from August 11, 2017 to June 12, 2019. LT recipients with end-stage renal disease (ESRD) were defined by dialysis requirement or estimated glomerular filtration rate <25. We evaluated outcomes and center-level, regional, and national practice before and after the policy change. Nonparametric cumulative incidence of kidney-after-liver listing and transplant were modeled by era. A total of 6332 patients received SLKTs during the study period; fewer patients with glomerular filtration rate (GFR) ≥50 mL/min underwent SLKT over time (5.8%, 4.8%, 3.0%; P = 0.01 ). There was also less variability in GFR at transplant after policy implementation on center and regional levels. We then evaluated LT-alone (LTA) recipients with ESRD (n = 5408 from 2012-2017; n = 2321 after the policy). Listing for a kidney within a year of LT increased from 2.9% before the policy change to 8.8% after the policy change, and the rate of kidney transplantation within 1 year increased from 0.7% to 4% (P < 0.001). After the policy change, there was no difference in patient survival rates between SLKT and LTA among patients with ESRD. Implementation of the 2017 SLKT policy change resulted in reduced variability in SLKT recipient kidney function and increased access to deceased donor kidney transplantation for LTA recipients with kidney disease without negatively affecting outcomes.

Need for improvements in simultaneous heart-kidney allocation: The limitation of pretransplant glomerular filtration rate

The incidence of simultaneous heart-kidney transplant (SHK) has increased markedly in the last 15 years. There are no universally agreed upon indications for SHK vs. heart alone (HA) transplant, and center evaluation processes vary widely. We utilized Scientific Registry of Transplant Recipients data from 2003 to 2017 to quantify changes in the practice of SHK, examine the survival of SHK vs. HA, and identify patients with marginal benefit from SHK. We used Kaplan-Meier curves and Cox proportional hazards to assess differences in survival. The incidence of SHK increased more than fourfold between 2003 and 2017 from 1.6% to 6.6% of total hearts transplanted, while the proportion of dialysis-dependent patients undergoing SHK has remained constant. SHK was associated with increased survival in dialysis-dependent patients (Median Survival SHK: 12.6 vs. HA: 7.1 years p < .0001) but not with nondialysis-dependent patients (Median Survival SHK: 12.5 vs. HA 12.3, p = .24). The marginal effect of SHK in decreasing the hazard of death diminished with increasing eGFR. Delayed graft function occurred in 26% of SHK recipients. Posttransplant chronic dialysis was similar for both operations (6.4% of HA and 6.0% of SHK). Further study is needed to define patients who benefit from SHK.

Impact of Covid-19 on kidney transplant and waiting list patients: Lessons from the first wave of the pandemic

Background

The first wave of the Covid-19 pandemic resulted in a drastic reduction in kidney transplantation and a profound change in transplant care in France. It is critical for kidney transplant centers to understand the behaviors, concerns and wishes of transplant recipients and waiting list candidates.

Methods

French kidney patients were contacted to answer an online electronic survey at the end of the lockdown.

Results

At the end of the first wave of the pandemic in France (11 May 2020), 2112 kidney transplant recipients and 487 candidates answered the survey. More candidates than recipients left their home during the lockdown, mainly for health care (80.1% vs. 69.4%; P < 0.001). More candidates than recipients reported being exposed to Covid-19 patients (2.7% vs. 1.2%; P = 0.006). Many recipients and even more candidates felt inadequately informed by their transplant center during the pandemic (19.6% vs. 54%; P < 0.001). Among candidates, 71.1% preferred to undergo transplant as soon as possible, 19.5% preferred to wait until Covid-19 had left their community, and 9.4% were not sure what to do.

Conclusions

During the Covid-19 pandemic in France, the majority of candidates wished to receive a transplant as soon as possible without waiting until Covid-19 had left their community. Communication between kidney transplant centers and patients must be improved to better understand and serve patients’ needs.

Decreased graft loss following implementation of the kidney allocation score (KAS)

BACKGROUND

The Kidney Allocation System (KAS) was developed to improve equity and utility in organ allocation. We examine the effect of this change on kidney graft distribution and survival.

METHODS

UNOS data was used to identify first-time adult recipients of a deceased donor kidney-alone transplant pre-KAS (Jan 2012-Dec 2014, n = 26,612) and post-KAS (Jan 2015-Dec 2017, n = 30,701), as well as grafts recovered Jan 2012-Jun 2019.

RESULTS

Post-KAS, kidneys were more likely to experience cold ischemia time >24 h (20.0% vs. 18.8%, p < 0.001) and experienced more delayed graft function, though competing risks modeling demonstrated a lower hazard of graft loss post-KAS, HR 0.90 (95% CI 0.84-0.97, p = 0.007). Post-policy, KDPI >85% kidneys were more likely to be shared regionally (37% vs. 14%), and more likely to be discarded (60.6% vs. 54.9%) after the policy change. KDPI >85% graft and patient survival did not change.

CONCLUSIONS

Implementation of the KAS has increased sharing of high-KDPI kidneys and has decreased the hazard of graft loss without an impact on patient survival.

Effects of Sofosbuvir-Based Hepatitis C Treatment Regimens on Calcineurin Inhibitor Dosing in Liver and Kidney Transplant Recipients

OBJECTIVES

Available data have suggested that directacting antivirals for hepatitis C virus may decrease calcineurin inhibitor concentrations. In this study, our aim was to determine the effects of hepatitis C directacting antivirals on calcineurin inhibitor doses and trough levels.

MATERIALS AND METHODS

This retrospective, singlecenter study included 52 abdominal transplant recipients treated with sofosbuvir-based regimens between 2014 and 2017. The primary outcome was percent change in calcineurin inhibitor troughs and total daily doses between the week before treatment with direct-acting antivirals, days 21 to 35 oftreatment, and days 21 to 35 aftertreatment. Secondary outcomes included sustained virologic response and biopsyproven acute rejection rates.

RESULTS

The median percent difference in calcineurin inhibitor troughs from pretreatment to during treatment was -20.5% (interquartile range, -36.2% to 13.1%) and from pretreatment to posttreatment was -13.5% (interquartile range, -33.7% to 10.7%). Corresponding percent changes in calcineurin inhibitor doses were 0% (interquartile range, 0%-0%) and 0% (interquartile range, -10.5% to 33.3%), respectively. Patients on tacrolimus experienced statistically significant changes in troughs but not doses. During treatment, 65% of patients required no dose change, 23% underwent a dose increase, and 12% had a dose decrease. The sustained virologic response rate was 98%, and the biopsy-proven acute rejection rate was 0%.

CONCLUSIONS

Hepatitis C direct-acting antiviraltherapy may decrease calcineurin inhibitor levels, but this was not associated with clinically different dosing requirements or rejection rates.

Lymphocyte depletion and risk of acute rejection in renal transplant recipients at increased risk for delayed graft function

Delayed graft function (DGF) is a risk factor for acute rejection (AR) in renal transplant recipients, and KDIGO guidelines suggest use of lymphocyte-depletion induction when DGF is anticipated. We analyzed the United Network for Organ Sharing/Organ Procurement and Transplantation Network (UNOS/OPTN) database to assess the impact of induction immunosuppression on the risk of AR in deceased kidney recipients based on pretransplant risk of DGF using a validated model. Recipients were categorized into 4 groups based upon the induction immunosuppression: (1) Rabbit anti-thymocyte globulin (rATG); (2) Alemtuzumab (C1H); (3) IL2-receptor antagonists (IL2-RA; basiliximab or daclizumab), and (4) No antibody induction. The primary endpoint for analysis was a composite endpoint of treated AR or graft failure by 1-year posttransplantation. Compared to no antibody induction, rATG and C1H had consistently lower adjusted odds of the composite endpoint across all risk strata for DGF risk, whereas IL2-Ra was associated with increased adjusted odds of the composite endpoint with increasing DGF risk. When the induction agents were compared, rATG and C1H were associated with decreasing adjusted odds for the composite endpoint with increasing risk of DGF, especially at the higher risk spectrum of DGF. Consideration must be given to use of lymphocyte-depletion induction when the anticipated risk of DGF is increased.

Trends in Usage and Outcomes for Expanded Criteria Donor Kidney Transplantation in the United States Characterized by Kidney Donor Profile Index

There has been increasing concern in the kidney transplant community about the declining use of expanded criteria donors (ECD) despite improvement in survival and quality of life. The recent introduction of the Kidney Donor Profile Index (KDPI), which provides a more granular characterization of donor quality, was expected to increase utilization of marginal kidneys and decrease the discard rates. However, trends and practice patterns of ECD kidney utilization on a national level based on donor organ quality as per KDPI are not well known. We, therefore, performed a trend analysis of all ECD recipients in the United Network for Organ Sharing (UNOS) registry between 2002 and 2012, after calculating the corresponding KDPI, to enable understanding the trends of usage and outcomes based on the KDPI characterization. High-risk recipient characteristics (diabetes, body mass index ≥30 kg/m², hypertension, and age ≥60 years) increased over the period of the study (trend test p<0.001 for all). The proportion of ECD transplants increased from 18% in 2003 to a peak of 20.4% in 2008 and then declined thereafter to 17.3% in 2012. Using the KDPI >85% definition, the proportion increased from 9.4% in 2003 to a peak of 12.1% in 2008 and declined to 9.7% in 2012. Overall, although this represents a significant utilization of kidneys with KDPI >85% over time (p<0.001), recent years have seen a decline in usage, probably related to regulations imposed by Centers for Medicare & Medicaid Services (CMS).

When comparing the hazards of graft failure by KDPI, ECD kidneys with KDPI >85% have a slightly lower risk of graft failure compared to standard criteria donor (SCD) kidneys with KDPI >85%, with a hazard ratio (HR) of 0.95, a confidence interval (CI) of 0.94-0.96, and statistical significance of p<0.001. This indicates that some SCD kidneys may actually have a lower estimated quality, with a higher Kidney Donor Risk Index (KDRI), than some ECDs. The incidence of delayed graft function (DGF) in ECD recipients has significantly decreased over time from 35.2% in 2003 to 29.6% in 2011 (p=0.007), probably related to better understanding of the donor risk profile along with increased use of hypothermic machine perfusion and pretransplant biopsy to aid in optimal allograft selection.

The recent decline in transplantation of KDPI >85% kidneys probably reflects risk-averse transplant center behavior. Whether discard of discordant SCD kidneys with KDPI >85% has contributed to this decline remains to be studied.

Effects of Ideal Versus Total Body Weight Dosage of Rabbit Antithymocyte Globulin on Outcomes of Kidney Transplant Patients With High Immunologic Risk

OBJECTIVES

The optimal dose of rabbit antithymocyte globulin induction therapy in kidney transplant recipients with high immunologic risk lacks consensus. The purpose of this study was to evaluate the effect of using ideal body weight rather than total body weight for the weight-based dose calculations in this patient population.

MATERIALS AND METHODS

Data were retrospectively collected on 89 adult patients who received rabbit antithymocyte globulin induction therapy for high immunologic risk kidney transplant. Hospital protocol changed from the use of cumulative rabbit antithymocyte globulin doses of 7.5 mg/kg total body weight to 7.5 mg/kg ideal body weight in 2009. Patients were separated into 2 cohorts based on the amount of rabbit antithymocyte globulin (in mg/kg total body weight) received. Rate of biopsy-proven acute rejection, patient survival, and allograft function were evaluated at 90 days and 1 year after transplant. Cost of induction therapy was also evaluated.

RESULTS

Baseline demographics were predominantly similar between the 2 cohorts. No significant difference in maintenance immunosuppression was identified. Rates of biopsy-proven acute rejection at 90 days and 1 year were similar between ideal and total body weight cohorts (4.2% vs 0% at 90 days, P = .5; 8.7% vs 0% at 1 year, P = .13). Patient survival and allograft function were also similar. Median cost of rabbit antithymocyte globulin induction therapy per patient was lower in the ideal body weight cohort, but this difference was not statistically significant ($17 542 vs $19 934; P = .3).

CONCLUSIONS

Our results suggest that use of ideal body weight for dose calculations of rabbit antithymocyte globulin induction therapy in high immunologic risk kidney transplant recipients at 7.5 mg/kg results in low rates of acute rejection with a safety profile similar to that shown with a total body weight dosage. Use of ideal body weight for lower cumulative doses may still need further evaluation in this patient population.

Impact of acute kidney injury on chronic kidney disease and its progression

Acute kidney injury (AKI) is a devastating clinical problem that affects a growing number of patients, especially elderly ones, and is associated with high morbidity and mortality. It was previously thought that patients who survive an episode of AKI recover renal function without further sequelae; however, recent population- based studies suggest that this may not be the case. New clinical studies suggest that a strikingly large percentage of patients who have AKI do not fully recover renal function or require permanent renal replacement therapy, and that this population has an important impact on the epidemiology of chronic kidney disease (CKD) and end-stage renal disease. These clinical studies verify animal studies that have established a link between AKI and CKD progression. Future clinical studies are underway to prospectively characterize the natural history of AKI and CKD progression and to identify predictive biomarkers.

Care of the undocumented immigrant in the United States with ESRD

The growth of the undocumented immigrant population in the United States has been explosive. The absence of a uniform policy regarding health care for this population has created a unique problem for nephrologists. How should provision of care for undocumented immigrants with end-stage renal disease be delivered and compensated? This problem is exacerbated by the multiple complex laws that govern delivery of and payment for care, as well as that state regulations vary widely and are not easily understood. Furthermore, the ethical and moral commitments of providers to ensure adequate and appropriate care for any patient whose life is at stake, irrespective of his or her immigration status, place nephrologists in a difficult position. This review focuses on the scope of this problem, relevant case law and legislation, current care and payment models, the response of nephrology groups, and ethical dilemmas inherent in caring for this vulnerable population. Recommendations for further study, including convening of a consensus conference, are discussed.