Identifying appropriate recipients for CDC infectious risk donor kidneys

Organ Nonutilization Following Revision to the Public Health Service Donor Risk Criteria for HIV, HCV, or HBV Transmission

BACKGROUND

Organs from Public Health Service criteria (PHSC) donors, previously referred to as PHS infectious-risk donors, have historically been recovered but not used, traditionally referred to as "discard," at higher rates despite negligible risk to recipients. On March 1, 2021, the definition of PHSC donors narrowed to include only the subset of donors deemed to have meaningfully elevated risk in the current era of improved infectious disease testing.

METHODS

Using Scientific Registry of Transplant Recipients data from May 1, 2019, to December 31, 2022, we compared rates of PHSC classification and nonutilization of PHSC organs before versus after the March 1, 2021, policy change among recovered decedents using the χ 2 tests. We performed an adjusted interrupted time series analysis to examine kidney and liver recovery/nonuse (traditionally termed "discard") and kidney, liver, lung, and heart nonutilization (nonrecovery or recovery/nonuse) prepolicy versus postpolicy.

RESULTS

PHSC classification dropped sharply from 24.5% prepolicy to 15.4% postpolicy ( P  < 0.001). Before the policy change, PHSC kidney recovery/nonuse, liver nonuse, lung nonuse, and heart nonuse were comparable to non-PHSC estimates (adjusted odds ratio: kidney =  0.98 1.06 1.14 , P  = 0.14; liver =  0.85 0.92 1.01 , P  = 0.07; lung =  0.91 0.99 1.08 , P  = 0.83; heart =  0.89 0.97 1.05 , P  = 0.47); following the policy change, PHSC kidney recovery/nonuse, liver nonuse, lung nonuse, and heart nonuse were lower than non-PHSC estimates (adjusted odds ratio: kidney =  0.77 0.84 0.91 , P  < 0.001; liver =  0.77 0.84 0.92 , P  < 0.001; lung =  0.74 0.81 0.90 , P  < 0.001; heart =  0.61 0.67 0.73 , P  < 0.001).

CONCLUSIONS

Even though PHSC donors under the new definition are a narrower and theoretically riskier subpopulation than under the previous classification, PHSC status appears to be associated with a reduced risk of kidney and liver recovery/nonuse and nonutilization of all organs. Although historically PHSC organs have been underused, our findings demonstrate a notable shift toward increased PHSC organ utilization.

Knowing When to Pass: The Effect of AI Reliability in Risky Decision Contexts

OBJECTIVE

This study manipulates the presence and reliability of AI recommendations for risky decisions to measure the effect on task performance, behavioral consequences of trust, and deviation from a probability matching collaborative decision-making model.

BACKGROUND

Although AI decision support improves performance, people tend to underutilize AI recommendations, particularly when outcomes are uncertain. As AI reliability increases, task performance improves, largely due to higher rates of compliance (following action recommendations) and reliance (following no-action recommendations).

METHODS

In a between-subject design, participants were assigned to a high reliability AI, low reliability AI, or a control condition. Participants decided whether to bet that their team would win in a series of basketball games tying compensation to performance. We evaluated task performance (in accuracy and signal detection terms) and the behavioral consequences of trust (via compliance and reliance).

RESULTS

AI recommendations improved task performance, had limited impact on risk-taking behavior, and were under-valued by participants. Accuracy, sensitivity (d'), and reliance increased in the high reliability AI condition, but there was no effect on response bias (c) or compliance. Participant behavior was only consistent with a probability matching model for compliance in the low reliability condition.

CONCLUSION

In a pay-off structure that incentivized risk-taking, the primary value of the AI recommendations was in determining when to perform no action (i.e., pass on bets).

APPLICATION

In risky contexts, designers need to consider whether action or no-action recommendations will be more influential to design appropriate interventions.

Cost-effectiveness of Kidney Transplantation From Donors at Increased Risk of Blood-borne Virus Infection Transmission

BACKGROUND

Demand for donor kidneys outstrips supply. Using kidneys from selected donors with an increased risk of blood-borne virus (BBV) transmission (hepatitis B virus and hepatitis C virus [HCV], human immunodeficiency virus) may expand the donor pool, but cost-effectiveness of this strategy is uncertain.

METHODS

A Markov model was developed using real-world evidence to compare healthcare costs and quality-adjusted life years (QALYs) of accepting kidneys from deceased donors with potential increased risk of BBV transmission, because of increased risk behaviors and/or history of HCV, versus declining these kidneys. Model simulations were run over a 20-y time horizon. Parameter uncertainty was assessed through deterministic and probabilistic sensitivity analyses.

RESULTS

Accepting kidneys from donors at increased risk of BBVs (2% from donors with increased-risk behaviors and 5% from donors with active or past HCV infection) incurred total costs of 311 303 Australian dollars with a gain of 8.53 QALYs. Foregoing kidneys from these donors incurred total costs of $330 517 and a gain of 8.44 QALYs. A cost-saving of $19 214 and additional 0.09 QALYs (~33 d in full health) per person would be generated compared with declining these donors. Increasing the availability of kidneys with increased risk by 15% led to further cost-savings of $57 425 and additional 0.23 QALY gains (~84 d in full health). Probabilistic sensitivity analysis using 10 000 iterations showed accepting kidneys from donors at increased risk led to lower costs and higher QALY gains.

CONCLUSIONS

Shifting clinical practice to accept increased BBV risk donors would likely produce lower costs and higher QALYs for health systems.

Predicting a kidney transplant patient's pre-transplant functional status based on information from waitlist registration

With over 100,000 patients on the kidney transplant waitlist in 2019, it is important to understand if and how the functional status of a patient may change while on the waitlist. Recorded both at registration and just prior to transplantation, the Karnofsky Performance Score measures a patient's functional status and takes on values ranging from 0 to 100 in increments of 10. Using machine learning techniques, we built a gradient boosting regression model to predict a patient's pre-transplant functional status based on information known at the time of waitlist registration. The model's predictions result in an average root mean squared error of 12.99 based on 5 rolling origin cross validations and 12.94 in a separate out-of-time test. In comparison, predicting that the pre-transplant functional status remains the same as the status at registration, results in average root mean squared errors of 14.50 and 14.11 respectively. The analysis is based on 118,401 transplant records from 2007 to 2019. To the best of our knowledge, there has been no previously published research on building a model to predict kidney pre-transplant functional status. We also find that functional status at registration and total serum albumin, have the most impact in predicting the pre-transplant functional status.

A Systematic Review of Kidney Transplantation Decision Modelling Studies

BACKGROUND

Genome-based precision medicine strategies promise to minimize premature graft loss after renal transplantation, through precision approaches to immune compatibility matching between kidney donors and recipients. The potential adoption of this technology calls for important changes to clinical management processes and allocation policy. Such potential policy change decisions may be supported by decision models from health economics, comparative effectiveness research and operations management.

OBJECTIVE

We used a systematic approach to identify and extract information about models published in the kidney transplantation literature and provide an overview of the status of our collective model-based knowledge about the kidney transplant process.

METHODS

Database searches were conducted in MEDLINE, Embase, Web of Science and other sources, for reviews and primary studies. We reviewed all English-language papers that presented a model that could be a tool to support decision making in kidney transplantation. Data were extracted on the clinical context and modelling methods used.

RESULTS

A total of 144 studies were included, most of which focused on a single component of the transplantation process, such as immunosuppressive therapy or donor-recipient matching and organ allocation policies. Pre- and post-transplant processes have rarely been modelled together.

CONCLUSION

A whole-disease modelling approach is preferred to inform precision medicine policy, given its potential upstream implementation in the treatment pathway. This requires consideration of pre- and post-transplant natural history, risk factors for allograft dysfunction and failure, and other post-transplant outcomes. Our call is for greater collaboration across disciplines and whole-disease modelling approaches to more accurately simulate complex policy decisions about the integration of precision medicine tools in kidney transplantation.

Waitlisted and Transplant Patient Perspectives on Expanding Access to Deceased-Donor Kidney Transplant: A Qualitative Study

Background:

A concerning number of kidneys (eg, expanded donor criteria, extended criteria, or marginal kidneys) are discarded yearly while patients experience significant morbidity and mortality on the transplant waitlist. Novel solutions are needed to solve the shortage of kidneys available for transplant. Patient perceptions regarding the use of these less than ideal kidneys remain unexplored.

Objective:

To explore the perspectives of patients who have previously received a less than ideal kidney in the past and patients awaiting transplant who could potentially benefit from one.

Design:

Qualitative description study.

Setting:

2 provinces in Canada participated (Saskatchewan and Manitoba).

Patients:

Patients with end-stage kidney disease who were awaiting kidney transplant and were either (a) aged 65 years and older, or (b) 55 years and older with other medical conditions (eg, diabetes).

Methods:

Criterion sampling was used to identify participants. Semi-structured, one-on-one interviews were conducted virtually, which explored perceived quality of life, perceptions of less than ideal kidneys, risk tolerance for accepting one, and educational needs to make such a choice. The interviews were transcribed verbatim and thematic analysis was used to analyze the data.

Results:

15 interviews were conducted with usable data (n = 10 pretransplant; n = 5 posttransplant). Participants were a mean of 65.5 ± 8.8 years old. Four interrelated themes became prominent including (1) patient awareness and understanding of their situation or context, (2) a desire for information, (3) a desire for freedom from dialysis, and (4) trust. Subthemes of transparency, clarity, standardization, and autonomy were deemed important for participant education. The majority of pretransplant participants (n = 8/10) indicated that between 3 and 5 years off of dialysis would make the risk of accepting a less than ideal kidney feel worthwhile.

Limitation:

The study setting was limited to 2 Canadian provinces, which limits the generalizability. Furthermore, the participants were homogenous in demographics such as ethnicity.

Conclusion:

These findings indicate that patients are comfortable to accept a less than ideal kidney for transplant in situations where their autonomy is respected, they are provided clear, standardized, and transparent information, and when they trust their physician. These results will be used to inform the development of a new national registry for expanding access to deceased-donor kidney transplant.

Trial Registration:

Not registered.

Successful Use of Kidneys from a Deceased Donor with Active Herpes Zoster Infection

Background

The limited donor pool and increasing recipient wait list require a reevaluation of kidney organ suitability for transplantation. Use of higher infectious risk organs that were previously discarded may help improve access to transplantation and reduce patient mortality without placing patients at a higher risk of poor posttransplant outcomes. There is very little data available regarding the safe use of kidney organs from deceased donors with varicella zoster virus infection at the time of organ retrieval. Case Presentation. Here, we report a case of successful transplantation of both kidneys from a deceased donor with active herpes zoster infection at the time of organ retrieval. Recipients were treated preemptively with acyclovir. At 4 months posttransplant, both kidney recipients experienced no infectious complications and were off dialysis with functioning transplant grafts.

Conclusions

The use of kidney organs from donors with active herpes zoster infection appears to be a safe option to expand the kidney donor pool.

Increased-risk donors and solid organ transplantation: current practices and opportunities for improvement

PURPOSE OF REVIEW

The development and implementation of 'increased risk donor' (IRD) status by the Centers for Disease Control (CDC) was intended to guide patients and providers in decision making regarding risk of infectious transmission via solid organ transplantation. Several contemporary studies have shown underutilization of these organs. This review summarizes the issues surrounding IRD status as well as recent advances in our understanding of the risks and benefits of increased risk organs and their appropriate utilization.

RECENT FINDINGS

Risk of window-period infection remains exceedingly low, and implementation of nucleic acid testing for HIV and hepatitis C virus (HCV) has resulted in decreasing risk of window-period infection often by an order of magnitude or more. Surgeons remain hesitant to utilize IRD organs. In addition, surgeon assessment of risk by donor behaviour was often discordant with known risks of those behaviours. Studies investigating outcomes of utilization of IRD organs suggest long-term mortality and graft survival is at least equivalent to non-IRD organs. Contemporary results suggest that IRD organs continue to be underutilized, particularly adult kidneys and lungs, with hundreds of wasted organs per year.

SUMMARY

CDC IRD labelling has led to an underutilization of organs for transplantation. The risks associated with acceptance of an IRD organ are inflated by surgeons and patients, and outcomes for patients who undergo transplantation with increased risk organs are similar to or better than those for patients whom accept standard risk organs. The rate of transmission of window-period infection from IRD organs is exceptionally low. The harms regarding the utility of Public Health Service increased risk classification outweigh the benefits for patients in need of transplant.

Educational Animations to Inform Transplant Candidates About Deceased Donor Kidney Options: An Efficacy Randomized Trial

Background

Transplant candidates struggle making decisions about accepting kidneys with variable kidney donor profile index (KDPI) and increased risk donor (IRD) status.

Methods

This single site, pilot randomized controlled trial evaluated the efficacy of 2 animations to improve KDPI/IRD knowledge, decisional self-efficacy, and willingness. Kidney candidates were randomly assigned to animation viewing plus standard nurse discussion (intervention) or standard nurse discussion alone (control). Linear regression was used to test the significance of animation exposure after controlling for covariates (α < 0.1).

Results

Mean age was 60 years, and 27% were African American. Both intervention (n = 42) and control (n = 38) groups received similar education at similar duration (12.8 versus 11.8 min, respectively), usually by the same dedicated nurse educator (85% versus 75%, respectively). On multivariate analysis, the intervention group (versus control) exhibited significantly increased knowledge (β = 0.23; 95% confidence interval, 0.66-1.77) and IRD willingness (β = 0.22; 95% confidence interval, 0.05-0.86). There were no between-group differences in KDPI >85% willingness or distribution of KDPI/IRD decisional self-efficacy. Over 90% of participants provided positive ratings on each of 11 acceptability items.

Conclusions

Supporting conventional IRD and KDPI education with educational animations can improve knowledge and IRD willingness compared with standard methods.

Using machine learning to estimate survival curves for patients receiving an increased risk for disease transmission heart, liver, or lung versus waiting for a standard organ

Introduction

Over 19% of deceased organ donors are labeled increased risk for disease transmission (IRD) for viral blood‐borne disease transmission. Many potential organ recipients need to decide between accepting an IRD organ offer and waiting for a non–IRD organ.

Methods

Using machine learning and simulation, we built transplant and waitlist survival models and compared the survival for patients accepting IRD organ offers or waiting for non–IRD organs for the heart, liver, and lung. The simulation consisted of generating 20 000 different scenarios of a recipient either receiving an IRD organ or waiting and receiving a non–IRD organ.

Results

In the simulations, the 5‐year survival probabilities of heart, liver, and lung recipients who accepted IRD organ offers increased on average by 10.2%, 12.7%, and 7.2%, respectively, compared with receiving a non–IRD organ after average wait times (190, 228, and 223 days, respectively). When the estimated waitlist time was at least 5 days for the liver, and 1 day for the heart and lung, 50% or more of the simulations resulted in a higher chance of 5‐year survival when the patient received an IRD organ versus when the patient remained on the waitlist. We also developed a simple equation to estimate the benefits, in terms of 5‐year survival probabilities, of receiving an IRD organ versus waiting for a non–IRD organ, for a particular set of recipient/donor characteristics.

Conclusion

For all three organs, the majority of patients are predicted to have higher 5‐year survival accepting an IRD organ offer compared with waiting for a non–IRD organ.

National Variation in Increased Infectious Risk Kidney Offer Acceptance

BACKGROUND

Despite providing survival benefit, increased risk for infectious disease (IRD) kidney offers are declined at 1.5 times the rate of non-IRD kidneys. Elucidating sources of variation in IRD kidney offer acceptance may highlight opportunities to expand use of these life-saving organs.

METHODS

To explore center-level variation in offer acceptance, we studied 6765 transplanted IRD kidneys offered to 187 transplant centers between 2009 and 2017 using Scientific Registry of Transplant Recipients data. We used multilevel logistic regression to determine characteristics associated with offer acceptance and to calculate the median odds ratio (MOR) of acceptance (higher MOR indicates greater heterogeneity).

RESULTS

Higher quality kidneys (per 10 units kidney donor profile index; adjusted odds ratio [aOR], 0.94; 95% confidence interval [CI], 0.92-0.95), higher yearly volume (per 10 deceased donor kidney transplants; aOR, 1.08, 95% CI, 1.06-1.10), smaller waitlist size (per 100 candidates; aOR, 0.97; 95% CI, 0.95-0.98), and fewer transplant centers in the donor service area (per center; aOR, 0.88; 95% CI, 0.85-0.91) were associated with greater odds of IRD acceptance. Adjusting for donor and center characteristics, we found wide heterogeneity in IRD offer acceptance (MOR, 1.96). In other words, if listed at a center with more aggressive acceptance practices, a candidate could be 2 times more likely to have an IRD kidney offer accepted.

CONCLUSIONS

Wide national variation in IRD kidney offer acceptance limits access to life-saving kidneys for many transplant candidates.

A mathematical model to describe survival among liver recipients from deceased donors with risk of transmitting infectious encephalitis pathogens

BACKGROUND

Between 2002 and 2013, the organs of 13 deceased donors with infectious encephalitis were transplanted, causing infections in 23 recipients. As a consequence, organs from donors showing symptoms of encephalitis (increased probability of infectious encephalitis (IPIE) organs) might be declined. We had previously characterized the risk of IPIE organs using data available to most transplant teams and not requiring special diagnostic tests. If the probability of infection is low, the benefits of a transplant from a donor with suspected infectious encephalitis might outweigh the risk and could be lifesaving for some transplant candidates.

METHODS

Using organ transplant data and Cox Proportional Hazards models, we determined liver donor and recipient characteristics predictive of post-transplant or waitlist survival and generated 5-year survival probability curves. We also calculated expected waiting times for an organ offer based on transplant candidate characteristics. Using a limited set of actual cases of infectious encephalitis transmission via transplant, we estimated post-transplant survival curves given an organ from an IPIE donor.

RESULTS

54% (1256) of patients registered from 2002-2006 who died or were removed from the waiting list because of deteriorated condition within 1 year could have had an at least marginal estimated benefit by accepting an IPIE liver with some probability of infection, with the odds increasing to 86% of patients if the probability of infection was low (5% or less). Additionally, 54% (1252) were removed from the waiting list prior to their estimated waiting time for a non-IPIE liver and could have benefited from an IPIE liver.

CONCLUSION

Improved allocation and utilization of IPIE livers could be achieved by evaluating the patient-specific trade-offs between (a) accepting an IPIE liver and (b) remaining on the waitlist and accepting a non-IPIE liver after the estimated waiting time.

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.

Development and Preliminary Evaluation of IRD-1-2-3: An Animated Video to Inform Transplant Candidates About Increased Risk Donor Kidneys

BACKGROUND

Current educational interventions about increased risk donors (IRDs) are less effective in improving knowledge among African American (AA) kidney transplant candidates compared to other races. We aimed to develop an IRD educational animated video culturally responsive to AAs and conduct feasibility testing.

METHODS

Between May 1, 2018, and June 25, 2018, we iteratively refined a culturally targeted video for AAs with input from multiple stakeholders. We then conducted a one group pre-post study between June 28, 2018, and October 29, 2018, with 40 kidney transplant candidates to assess the feasibility and acceptability of the video to improve participant knowledge and obtain feedback about IRD understanding, self-efficacy, and willingness. A mixed population was chosen to obtain race-specific acceptability data and efficacy estimates to inform a larger study.

RESULTS

Three themes emerged and informed video development; misattribution of IRD to kidney quality, IRD terminology as a barrier to meaningful understanding, and variable reactions to a 1:1000 risk estimate. The study cohort was 50% AA. Median IRD knowledge increased from 5 to 7.5 (P = 0.001) overall and from 5 to 7 (P < 0.001) among AAs. The frequency of positive responses increased pre-post video for understanding of (23% vs 83%, P < 0.001), self-efficacy to decide about (38% vs 70%, P < 0.001), and willingness to accept IRD kidneys (25% vs 72%, P < 0.001). Over 90% of participants provided positive ratings on each of the 6 acceptability items.

CONCLUSIONS

A culturally responsive IRD educational video was developed in collaboration with key stakeholders. Quantitative results indicate the video was acceptable and promising to impact IRD knowledge among AA and non-AA kidney transplant candidates.

Expanding deceased donor kidney transplantation: medical risk, infectious risk, hepatitis C virus, and HIV

PURPOSE OF REVIEW

Due to the organ shortage, which prevents over 90 000 individuals in the United States from receiving life-saving transplants, the transplant community has begun to critically reevaluate whether organ sources that were previously considered too risky provide a survival benefit to waitlist candidates.

RECENT FINDINGS

Organs that many providers were previously unwilling to use for transplantation, including kidneys with a high Kidney Donor Profile Index or from increased risk donors who have risk factors for window period hepatitis C virus (HCV) and HIV infection, have been shown to provide a survival benefit to transplant waitlist candidates compared with remaining on dialysis. The development of direct-acting antivirals to cure HCV infection has enabled prospective trials on the transplantation of organs from HCV-infected donors into HCV-negative recipients, with promising preliminary results. Changes in legislation through the HIV Organ Policy Equity Act have legalized transplantations from HIV-positive deceased donors to HIV-positive recipients for the first time in the United States.

SUMMARY

Critical reexamination of deceased donor organs that were previously discarded has resulted in greater utilization of these organs, an increased number of deceased donor transplants, and the provision of life-saving treatment to more transplant waitlist candidates.

Prospective Validation of Prediction Model for Kidney Discard

BACKGROUND

Many kidneys are discarded every year, with 3631 kidneys discarded in 2016 alone. Identifying kidneys at high risk of discard could facilitate "rescue" allocation to centers more likely to transplant them. The Probability of Delay or Discard (PODD) model was developed to identify marginal kidneys at risk of discard or delayed allocation beyond 36 hours of cold ischemia time. However, PODD has not been prospectively validated, and patterns of discard may have changed after policy changes such as the introduction of Kidney Donor Profile Index and implementation of the Kidney Allocation System (KAS).

METHODS

We prospectively validated the PODD model using Scientific Registry of Transplant Recipients data in the KAS era (January 1, 2015, to March 1, 2018). C statistic was calculated to assess accuracy in predicting kidney discard. We assessed clustering in centers' utilization of kidneys with PODD >0.6 ("high-PODD") using Gini coefficients. Using match run data from January 1, 2015, to December 31, 2016, we examined distribution of these high-PODD kidneys offered to centers that never accepted a high-PODD kidney.

RESULTS

The PODD model predicted discard accurately under KAS (C-statistic, 0.87). Compared with utilization of low-PODD kidneys (Gini coefficient = 0.41), utilization of high-PODD kidneys was clustered more tightly among a few centers (Gini coefficient, 0.84 with >60% of centers never transplanted a high-PODD kidneys). In total, 11684 offers (35.0% of all high-PODD offers) were made to centers that never accepted a high-PODD kidney.

CONCLUSIONS

Prioritizing allocation of high-PODD kidneys to centers that are more likely to transplant them might help reduce kidney discard.

Using machine learning and an ensemble of methods to predict kidney transplant survival

We used an ensemble of statistical methods to build a model that predicts kidney transplant survival and identifies important predictive variables. The proposed model achieved better performance, measured by Harrell’s concordance index, than the Estimated Post Transplant Survival model used in the kidney allocation system in the U.S., and other models published recently in the literature. The model has a five-year concordance index of 0.724 (in comparison, the concordance index is 0.697 for the Estimated Post Transplant Survival model, the state of the art currently in use). It combines predictions from random survival forests with a Cox proportional hazards model. The rankings of importance for the model’s variables differ by transplant recipient age. Better survival predictions could eventually lead to more efficient allocation of kidneys and improve patient outcomes.

Implications of declining donor offers with increased risk of disease transmission on waiting list survival in lung transplantation

BACKGROUND

Donors with characteristics that may increase the likelihood of disease transmission with transplantation are noted as increased risk via Public Health Service criteria. This study aimed to establish the implications of declining an increased-risk donor (IRD) organ offer in lung transplantation.

METHODS

Adult candidates waitlisted for isolated lung transplantation in the United States using the Organ Procurement and Transplantation Network /United Network of Organ Sharing registry from 2007 to 2017 were identified. Individual match run files identified candidate recipients who matched to an IRD offer. Competing-risks analysis ascertained the likelihood of survival to transplantation. A stratified Cox model and restricted mean survival times estimated the survival benefit associated with the acceptance of an IRD organ.

RESULTS

A total of 6,963 candidates met inclusion criteria, and 1,473 (21.2%) accepted an IRD offer. Candidates who accepted an IRD offer were older, more likely to be male, and had a higher lung allocation score at the time of listing (all p < 0.05). At 1 year after an IRD offer decline, 70.5% of candidates underwent a lung transplant, 13.8% died or decompensated, and 14.9% were still awaiting transplant. Compared with those who declined, candidates who accepted the IRD offer had significantly improved cumulative mortality at 1 year (14.1% vs 23.9%, p < 0.001) and 5 years (48.4% vs 53.8%, p < 0.001).

CONCLUSIONS

IRD organ declination is associated with a decreased rate of lung transplantation and worse survival. Overall post-transplant survival rates for those who survive to transplantation are equivalent.

Heart and lung organ offer acceptance practices of transplant programs are associated with waitlist mortality and organ yield

Variation in heart and lung offer acceptance practices may affect numbers of transplanted organs and create variability in waitlist mortality. To investigate these issues, offer acceptance ratios, or adjusted odds ratios, for heart and lung transplant programs individually and for all programs within donation service areas (DSAs) were estimated using offers from donors recovered July 1, 2016, and June 30, 2017. Logistic regressions estimated the association of DSA-level offer acceptance ratios with donor yield and local placement of organs recovered in the DSA. Competing risk methodology estimated the association of program-level offer acceptance ratios with incidence and rate of waitlist removals due to death or becoming too sick to undergo transplant. Higher DSA-level offer acceptance was associated with higher yield (odds ratios [ORs]: lung, _1.04 1.11_1.19 ; heart, _1.09 1.21_1.35 ) and more local placement of transplanted organs (ORs: lung, _1.01 1.12_1.24 ; heart, _1.47 1.69_1.93 ). Higher program-level offer acceptance was associated with lower incidence of waitlist removal due to death or becoming too sick to undergo transplant (hazard ratios [HRs]: heart, _0.80 0.86_0.93 ; lung, _0.67 0.75_0.83 ), but not with rate of waitlist removal (HRs: heart, _0.91 0.98_1.06 ; lung, _0.89 0.99_1.10 ). Heart and lung offer acceptance practices affected numbers of transplanted organs and contributed to program-level variability in the probability of waitlist mortality.

Assessment of risk for transplant-transmissible infectious encephalitis among deceased organ donors

BACKGROUND

There were 13 documented clusters of infectious encephalitis transmission via organ transplant from deceased donors to recipients during 2002-2013. Hence, organs from donors diagnosed with encephalitis are often declined because of concerns about the possibility of infection, given that there is no quick and simple test to detect causes of infectious encephalitis.

METHODS

We constructed a database containing cases of infectious and non-infectious encephalitis. Using statistical imputation, cross-validation, and regression techniques, we determined deceased organ donor characteristics, including demographics, signs, symptoms, physical exam, and laboratory findings, predictive of infectious vs non-infectious encephalitis, and developed a calculator which assesses the risk of infection.

RESULTS

Using up to 12 predictive patient characteristics (with a minimum of 3, depending on what information is available), the calculator provides the probability that a donor may have infectious vs non-infectious encephalitis, improving the prediction accuracy over current practices. These characteristics include gender, fever, immunocompromised state (other than HIV), cerebrospinal fluid elevation, altered mental status, psychiatric features, cranial nerve abnormality, meningeal signs, focal motor weakness, Babinski's sign, movement disorder, and sensory abnormalities.

CONCLUSION

In the absence of definitive diagnostic testing in a potential organ donor, infectious encephalitis can be predicted with a risk score. The risk calculator presented in this paper represents a prototype, establishing a framework that can be expanded to other infectious diseases transmissible through solid organ transplantation.

Transplanting hepatitis C virus-positive livers into hepatitis C virus-negative patients with preemptive antiviral treatment: A modeling study

Under current guidelines, hepatitis C virus (HCV)-positive livers are not transplanted into HCV-negative recipients because of adverse posttransplant outcomes associated with allograft HCV infection. However, HCV can now be cured post-LT (liver transplant) using direct-acting antivirals (DAAs) with >90% success; therefore, HCV-negative patients on the LT waiting list may benefit from accepting HCV-positive organs with preemptive treatment. Our objective was to evaluate whether and in which HCV-negative patients the potential benefit of accepting an HCV-positive (i.e., viremic) organ outweighed the risks associated with HCV allograft infection. We developed a Markov-based mathematical model that simulated a virtual trial of HCV-negative patients on the LT waiting list to compare long-term outcomes in patients: (1) willing to accept any (HCV-negative or HCV-positive) liver versus (2) those willing to accept only HCV-negative livers. Patients receiving HCV-positive livers were treated preemptively with 12 weeks of DAA therapy and had a higher risk of graft failure than those receiving HCV-negative livers. The model incorporated data from published studies and the United Network for Organ Sharing (UNOS). We found that accepting any liver regardless of HCV status versus accepting only HCV-negative livers resulted in an increase in life expectancy when Model for End-Stage Liver Disease (MELD) was ≥20, and the benefit was highest at MELD 28 (0.172 additional life-years). The magnitude of clinical benefit was greater in UNOS regions with higher HCV-positive donor organ rates, that is, Regions 1, 2, 3, 10, and 11. Sensitivity analysis demonstrated that model outcomes were robust.

CONCLUSION

Transplanting HCV-positive livers into HCV-negative patients with preemptive DAA therapy could improve patient survival on the LT waiting list. Our analysis can help inform clinical trials and minimize patient harm. (Hepatology 2018;67:2085-2095).

An economic assessment of contemporary kidney transplant practice

Kidney transplantation is the optimal therapy for end-stage renal disease, prolonging survival and reducing spending. Prior economic analyses of kidney transplantation, using Markov models, have generally assumed compatible, low-risk donors. The economic implications of transplantation with high Kidney Donor Profile Index (KDPI) deceased donors, ABO incompatible living donors, and HLA incompatible living donors have not been assessed. The costs of transplantation and dialysis were compared with the use of discrete event simulation over a 10-year period, with data from the United States Renal Data System, University HealthSystem Consortium, and literature review. Graft failure rates and expenditures were adjusted for donor characteristics. All transplantation options were associated with improved survival compared with dialysis (transplantation: 5.20-6.34 quality-adjusted life-years [QALYs] vs dialysis: 4.03 QALYs). Living donor and low-KDPI deceased donor transplantations were cost-saving compared with dialysis, while transplantations using high-KDPI deceased donor, ABO-incompatible or HLA-incompatible living donors were cost-effective (<$100 000 per QALY). Predicted costs per QALY range from $39 939 for HLA-compatible living donor transplantation to $80 486 for HLA-incompatible donors compared with $72 476 for dialysis. In conclusion, kidney transplantation is cost-effective across all donor types despite higher costs for marginal organs and innovative living donor practices.

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: _1.22 2.06_3.49 , 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 _0.50 0.67_0.90 , P = .006), and at 48% lower risk of death beyond 6 months postdecision (aHR _0.46 0.52_0.58 , 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.

Increased risk organ transplantation in the pediatric population

IRD organs are classified by the Public Health Service to be at above-average risk for harboring human immunodeficiency virus, hepatitis C, and hepatitis B. Traditionally underutilized, there exists even greater reluctance for their use in pediatric patients. We performed a retrospective analysis via the United Network for Organ Sharing database of all pediatric renal and hepatic transplants performed from 2004 to 2008 in the United States. Primary outcomes were patient and graft survival. Proportional hazards regression was performed to control for potentially confounding factors. Waitlist time, organ acceptance rates, and infectious transmissions were analyzed. There were 1830 SRD renal, 92 IRD renal, 1695 SRD hepatic, and 59 IRD hepatic transplants. There were no statistically significant differences in allograft or patient survival in either group. Acceptance rates of IRD organs were lower for kidney (1.5% IRD vs 4.82% SRD) and liver (1.99% IRD vs 4.51% SRD). One transmission of a bloodborne pathogen involving a pediatric recipient out of 7797 unique transplants was reported from 2008 to 2015. IRD organs appear to have equivalent outcomes. Increasing their utilization may improve access to transplant while decreasing wait times and circumventing waitlist morbidity and mortality.

Organ transplantation from "increased infectious risk donors": the experience of the Nord Italia Transplant program - A retrospective study

The purpose of this study was to assess the safety and the clinical outcome associated with organ transplantation from increased infectious risk donors (IRD). We retrospectively identified all adult deceased IRD referred to the Nord Italia Transplant program coordinating center from November 2006 to November 2011. All potential donors were screened for social risk factors that may increase the risk of donor-derived infection with human immunodeficiency (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV). All recipients were followed monthly for the first 6 months post-transplant. A total of 86 potential IRD were identified during the study period. Three hundred and seventy-nine organs from IRD were offered to the transplant centers, but only 185 (48.8%) were used for transplantation. Organs from IRD were transplanted into 174 recipients. The complete follow-up data were available for 152 of 174 (87.3%) recipients. During a mean follow-up of 11.7 months (median 12; range 2.4-12), no transmission of HIV, HBV, or syphilis was documented by serology and nucleic acid testing (NAT) testing. Two patients transplanted with organs from HCV-RNA-positive donors, as expected, developed post-transplant HCV infection. In conclusion, the use of organs from IRD was associated with a safe increase in the transplant procedures in our country.

Organ utilization from increased infectious risk donors: An observational study

BACKGROUND

Donors with an increased risk of transmitting human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV) (increased risk donors [IRDs]) are a potential source of organs for transplant. Organs from IRDs can be utilized with appropriate recipient consent and post-transplant follow-up. We reviewed the characteristics and utilization of IRDs in our Organ Procurement Organization (OPO) over a 2-year period.

METHODS

Donor information from April 1, 2013 to March 31, 2015 was obtained through the OPO database. Only consented donors were included. Donors were categorized as IRDs according to Health Canada/Canadian Standards Association (CSA) criteria.

RESULTS

A total of 494 potential donors were identified, of which 92 (18.6%) were IRDs. Of these, at least one organ was transplanted from 76 (82.6%). Risk factors for IRDs included injection drug user (IDU) (12%), men having sex with men (MSM) (7%), commercial sex worker (CSW) (4%), and incarceration (24%). Fifty-nine percent (253/429) of IRD organs were utilized. The most frequently used organ was kidney, followed by liver. Median number of organs recovered per IRD was 3 (interquartile range: 2-5). Nucleic acid testing (NAT) was performed in 18.5% (17/92) of IRDs. Reasons for NAT were IDU (n = 2), MSM (n = 2), CSW (n = 2), and previous incarceration (n = 7). Organ utilization from donors that had NAT was similar to donors who did not (94% vs 80%, P = .29). Follow-up NAT was done in <5% of recipients from IRDs.

CONCLUSIONS

In our cohort, IRDs comprised a significant proportion of donors. Utilization of IRD organs occurred at a significant rate regardless of pre-transplant NAT. These data suggest that multiple factors contribute to the perception of infectious risk from such organs.

New Insights Into the Alleged Kidney Donor Profile Index Labeling Effect on Kidney Utilization

The Kidney Donor Profile Index (KDPI) became a driving factor in deceased donor kidney allocation on December 4, 2014, with the implementation of the kidney allocation system (KAS). On April 20, 2016, the annual recalibration of the Kidney Donor Risk Index into KDPI was incorrectly programmed in DonorNet, resulting in erroneously high KDPI values, by between 1 and 21 percentage points (e.g. actual KDPI of 70% was displayed as 86%). The error was corrected on May 19, 2016, <24 h after being recognized. During this 30-day period, the distribution of recipients largely resembled pre-KAS patterns. The observed discard rate of 22.9% was higher than the post-KAS average of 19.6% (odds ratio [OR]: 1.22) but far lower than the projected rate of 31.4% (OR: 1.96) based on the usual discard rate by KDPI relationship, suggesting clinicians and patients did not rely heavily on this single number (KDPI) in kidney-utilization decisions. Still, risk-adjusted analyses suggest the elevated discard rate was most likely attributable to the erroneously high KDPIs, not a shift in donor characteristics or random chance. The rise in discard rate was sharply higher for kidneys with inflated KDPI that crossed the 85% policy threshold (OR: 1.46; p = 0.049) versus those that did not (OR: 1.06; p = 0.631).

Effect of a Mobile Web App on Kidney Transplant Candidates' Knowledge About Increased Risk Donor Kidneys: A Randomized Controlled Trial

BACKGROUND

Kidney transplant candidates (KTCs) must provide informed consent to accept kidneys from increased risk donors (IRD), but poorly understand them. We conducted a multisite, randomized controlled trial to evaluate the efficacy of a mobile Web application, Inform Me, for increasing knowledge about IRDs.

METHODS

Kidney transplant candidates undergoing transplant evaluation at 2 transplant centers were randomized to use Inform Me after routine transplant education (intervention) or routine transplant education alone (control). Computer adaptive learning method reinforced learning by embedding educational material, and initial (test 1) and additional test questions (test 2) into each chapter. Knowledge (primary outcome) was assessed in person after education (tests 1 and 2), and 1 week later by telephone (test 3). Controls did not receive test 2. Willingness to accept an IRD kidney (secondary outcome) was assessed after tests 1 and 3. Linear regression test 1 knowledge scores were used to test the significance of Inform Me exposure after controlling for covariates. Multiple imputation was used for intention-to-treat analysis.

RESULTS

Two hundred eighty-eight KTCs participated. Intervention participants had higher test 1 knowledge scores (mean difference, 6.61; 95% confidence interval [95% CI], 5.37-7.86) than control participants, representing a 44% higher score than control participants' scores. Intervention participants' knowledge scores increased with educational reinforcement (test 2) compared with control arm test 1 scores (mean difference, 9.50; 95% CI, 8.27-10.73). After 1 week, intervention participants' knowledge remained greater than controls' knowledge (mean difference, 3.63; 95% CI, 2.49-4.78) (test 3). Willingness to accept an IRD kidney did not differ between study arms at tests 1 and 3.

CONCLUSIONS

Inform Me use was associated with greater KTC knowledge about IRD kidneys above routine transplant education alone.

Optimal timing of hepatitis C treatment for patients on the liver transplant waiting list

The availability of oral direct-acting antivirals has altered the hepatitis C virus (HCV) treatment paradigm for both pre-liver transplant (LT) and post-LT patients. There is a perceived trade-off between pre-LT versus post-LT treatment of HCV-treatment may improve liver function but potentially decrease the likelihood of a necessary LT. Our objective was to identify LT-eligible patients with decompensated cirrhosis who would benefit (and not benefit) from pre-LT treatment based on their Model for End-Stage Liver Disease (MELD) scores. We simulated a virtual trial comparing long-term outcomes of pre-LT versus post-LT HCV treatment with oral direct-acting antivirals for patients with MELD scores between 10 and 40. We developed a Markov-based microsimulation model, which simulated the life course of patients on the transplant waiting list and after LT. Simulation of LT integrated data from recent trials of oral direct-acting antivirals (SOLAR 1 and 2), the United Network for Organ Sharing (UNOS), and other studies. The outcomes of the model included life expectancy, 1-year and 5-year patient survival, and mortality. Model-predicted patient survival was validated with UNOS data. We found that, at the national level, treating HCV before LT increased life expectancy if MELD was ≤27 but could decrease life expectancy at higher MELD scores. Depending on the UNOS region, the threshold MELD score to treat HCV pre-LT varied between 23 and 27 and was lower for UNOS regions 3, 10, and 11 and higher for regions 1, 2, 4, 5, 8, and 9. Sensitivity analysis showed that the thresholds were stable.

CONCLUSION

Our findings suggest that the optimal MELD threshold below which decompensated cirrhosis patients should receive HCV treatment while awaiting LT is between 23 and 27, depending on the UNOS region. (Hepatology 2017;65:777-788).

Increasing the Use of Kidneys From Unconventional and High-Risk Deceased Donors

In this paper, we have reviewed the literature and report on kidney donors that are currently used at relatively low rates. Kidneys from donors with acute kidney injury (AKI) seem to have outcomes equivalent to those from donors without AKI, provided one can rule out significant cortical necrosis. Kidneys from donors with preexisting diabetes or hypertension may have marginally lower aggregate survival but still provide patients with a significant benefit over remaining on the wait list. The Kidney Donor Profile Index derives only an aggregate association with survival with a very modest C statistic; therefore, the data indicated that this index should not be the sole reason to discard a kidney, except perhaps in patients with extremely low estimated posttransplant survival scores. It is important to note that the Scientific Registry of Transplant Recipients models of risk adjustment should allay concerns regarding regulatory issues for observed outcomes falling below expectations. The successful utilization of kidneys from donation after cardiac death over the past decade shows how expanding our thinking can translate into more patients benefiting from transplantation. Given the growing number of patients on the wait list, broadening our approach to kidney acceptance could have an important impact on the population with end-stage renal disease. Many lives could be prolonged by carefully considering use of kidneys that are often discarded.

Heart transplant outcomes in recipients of Centers for Disease Control (CDC) high risk donors

BACKGROUND

A lack of donor hearts remains a major limitation of heart transplantation. Hearts from Centers for Disease Control (CDC) high-risk donors can be utilized with specific recipient consent. However, outcomes of heart transplantation with CDC high-risk donors are not well known. We sought to define outcomes, including posttransplant hepatitis and human immunodeficiency virus (HIV) status, in recipients of CDC high-risk donor hearts at our institution.

METHODS

All heart transplant recipients from August 2010 to December 2014 (n = 74) were reviewed. Comparison of 1) CDC high-risk donor (HRD) versus 2) standard-risk donor (SRD) groups were performed using chi-squared tests for nominal data and Wilcoxon two-sample tests for continuous variables. Survival was estimated with Kaplan-Meier curves.

RESULTS

Of 74 heart transplant recipients reviewed, 66 (89%) received a SRD heart and eight (11%) received a CDC HRD heart. We found no significant differences in recipient age, sex, waiting list 1A status, pretransplant left ventricular assist device (LVAD) support, cytomegalovirus (CMV) status, and graft ischemia times (p = NS) between the HRD and SRD groups. All of the eight HRD were seronegative at the time of transplant. Postoperatively, there was no significant difference in rejection rates at six and 12 months posttransplant. Importantly, no HRD recipients acquired hepatitis or HIV. Survival in HRD versus SRD recipients was not significantly different by Kaplan-Meier analysis (log rank p = 0.644) at five years posttransplant.

CONCLUSION

Heart transplants that were seronegative at the time of transplant had similar posttransplant graft function, rejection rates, and five-year posttransplant survival versus recipients of SRD hearts. At our institution, no cases of hepatitis or HIV occurred in HRD recipients in early follow-up.

Utilization of Public Health Service Increased Risk Donors Yields Equivalent Outcomes in Liver Transplantation

Background. The PHS increased risk donor (IRD) is underutilized in liver transplantation. We aimed to examine the posttransplant outcomes in recipients of increased-risk organs. Methods. We analyzed 228,040 transplants in the Organ Procurement and Transplantation Network database from 2004 to 2013. Endpoints were graft failure and death. Results were controlled for demographics and comorbidities. Statistical analysis utilized Fisher's test and logistic regression. Results. 58,816 patients were identified (5,534 IRD, 53,282 non-IRD). IRDs were more frequently male (69.2% versus 58.3%, p < 0.001), younger (34 versus 39, p < 0.001), and less likely to have comorbidities (p < 0.001). Waitlist time was longer for IRD graft recipients (254 versus 238 days, p < 0.001). All outcomes were better in the IRD group. Graft failure (23.6 versus 27.3%, p < 0.001) and mortality (20.4 versus 22.3%, p = 0.001) were decreased in IRD graft recipients. However, in multivariate analysis, IRD status was not a significant indicator of outcomes. Conclusion. This is the first study to describe IRD demographics in liver transplantation. Outcomes are improved in IRD organ recipients; however, controlling for donor and recipient comorbidities, ischemia time, and MELD score, the differences lose significance. In multivariate analysis, use of IRD organs is noninferior, with similar graft failure and mortality despite the infectious risk.

A Survey of Increased Infectious Risk Donor Utilization in Canadian Transplant Programs

BACKGROUND

Donors at increased risk of transmitting viral infections are a potential source of transplantable organs. Studies demonstrate that organs from increased risk donors (IRDs) are associated with excellent outcomes. However, considerable variation in practice likely exists.

METHODS

We performed a cross-country survey of Canadian Organ Transplant centers to determine organ utilization practices from IRDs.

RESULTS

Of 40 surveys sent to transplant programs across Canada, 24 (60%) were returned. Of those, 60.9% (15/24) had a formal policy for their use, and 21.7% (5/24) had never accepted an IRD. Only 41.7% (10/24) had access to timely nucleic acid testing (NAT), and respondents were more likely to accept IRD if NAT was available. For example the likelihood of using organs from an intravenous drug user increased from 12.5% (4/24) with serology negative donors to 70.8% (17/24) if NAT was available and the donor had no increased activity within the window period (P < 0.001). Only 37.5% (9/24) discussed the use of IRDs with candidates at listing, with 54.2% (13/24) stating that having a standardized consent would increase utilization of IRDs.

CONCLUSIONS

The results suggest that availability of NAT would increase IRD utilization. In addition written policies and procedures on IRD use and the consent process would be recommended in many Canadian centers.

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 (IRR = 1.45, p < 0.001). 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 (RR = 1.52, p = 0.01). 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.

New Solutions to Reduce Discard of Kidneys Donated for Transplantation

Kidney transplantation is a cost-saving treatment that extends the lives of patients with ESRD. Unfortunately, the kidney transplant waiting list has ballooned to over 100,000 Americans. Across large areas of the United States, many kidney transplant candidates spend over 5 years waiting and often die before undergoing transplantation. However, more than 2500 kidneys (>17% of the total recovered from deceased donors) were discarded in 2013, despite evidence that many of these kidneys would provide a survival benefit to wait-listed patients. Transplant leaders have focused attention on transplant center report cards as a likely cause for this discard problem, although that focus is too narrow. In this review, we examine the risks associated with accepting various categories of donated kidneys, including discarded kidneys, compared with the risk of remaining on dialysis. With the goal of improving access to kidney transplant, we describe feasible proposals to increase acceptance of currently discarded organs.

Choosing the order of deceased donor and living donor kidney transplantation in pediatric recipients: a Markov decision process model

BACKGROUND

Most pediatric kidney transplant recipients eventually require retransplantation, and the most advantageous timing strategy regarding deceased and living donor transplantation in candidates with only 1 living donor remains unclear.

METHODS

A patient-oriented Markov decision process model was designed to compare, for a given patient with 1 living donor, living-donor-first followed if necessary by deceased donor retransplantation versus deceased-donor-first followed if necessary by living donor (if still able to donate) or deceased donor (if not) retransplantation. Based on Scientific Registry of Transplant Recipients data, the model was designed to account for waitlist, graft, and patient survival, sensitization, increased risk of graft failure seen during late adolescence, and differential deceased donor waiting times based on pediatric priority allocation policies. Based on national cohort data, the model was also designed to account for aging or disease development, leading to ineligibility of the living donor over time.

RESULTS

Given a set of candidate and living donor characteristics, the Markov model provides the expected patient survival over a time horizon of 20 years. For the most highly sensitized patients (panel reactive antibody > 80%), a deceased-donor-first strategy was advantageous, but for all other patients (panel reactive antibody < 80%), a living-donor-first strategy was recommended.

CONCLUSIONS

This Markov model illustrates how patients, families, and providers can be provided information and predictions regarding the most advantageous use of deceased donor versus living donor transplantation for pediatric recipients.