Temporal trends in kidney paired donation in the United States: 2006-2021 UNOS/OPTN database analysis.

Kidney paired donation (KPD) is a major innovation that is changing the landscape of kidney transplantation in the United States. We used the 2006-2021 United Network for Organ Sharing data to examine trends over time. KPD is increasing, with 1 in 5 living donor kidney transplants (LDKTs) in 2021 facilitated by KPD. The proportion of LDKT performed via KPD was comparable for non-Whites and Whites. An increasing proportion of KPD transplants are going to non-Whites. End-chain recipients are not identified in the database. To what extent these trends reflect how end-chain kidneys are allocated, as opposed to increase in living donation among minorities, remains unclear. Half the LDKT in 2021 in sensitized (panel reactive antibody ≥ 80%) and highly sensitized (panel reactive antibody ≥ 98%) groups occurred via KPD. Yet, the proportion of KPD transplants performed in sensitized recipients has declined since 2013, likely due to changes in the deceased donor allocation policies and newer KPD strategies such as compatible KPD. In 2021, 40% of the programs reported not performing any KPD transplants. Our study highlights the need for understanding barriers to pursuing and expanding KPD at the center level and the need for more detailed and accurate data collection at the national level.

Epidemiology and Risk Factors for Invasive Fungal Infections in Pancreas Transplant in the Absence of Postoperative Antifungal Prophylaxis.

Background: Invasive fungal infections (IFIs) remain a rare yet dreaded complication following pancreas transplantation. Current guidelines recommend antifungal prophylaxis in patients with 1 or more risk factors. At our center, single-dose antifungal prophylaxis is administered in the operating room but none subsequently, regardless of risk factors. Here we evaluate the 1-year incidence, outcome, and risk factors associated with IFI following pancreas transplantation. Methods: A retrospective, single-center cohort study was conducted in patients who underwent pancreas transplantation between 1 January 2009 and 31 December 2019. Records were manually reviewed, and cases were adjudicated using consensus definitions. The 1-year cumulative incidence, mortality, and risk factors were analyzed by Kaplan-Meier method and differences between populations were assessed with Fisher test and Mann-Whitney U test. Results: Three hundred sixty-nine recipients were included. Twelve IFIs were identified: candidiasis (8), aspergillosis (2), histoplasmosis (1), and cryptococcosis (1). Intra-abdominal infections were the most common presentation (5), followed by bloodstream infections (3), disseminated disease (2), pulmonary disease (1), and invasive fungal sinusitis (1). Median time to IFI was 64 days (interquartile range, 30-234 days). One-year cumulative incidence was 3.25% (95% confidence interval, 1.86%-5.65%). There were no significant differences between patients with or without IFI regarding type of transplant (P = .17), posttransplant dialysis (P = .3), rejection (P = .5), cytomegalovirus serostatus (P = .45), or reoperation (P = .19). For patients with IFI, the 1-year graft and patient survival rates were 58% versus 95% (P < .0001) and 75% versus 98.6% (P < .001), respectively. Conclusions: Our study suggests that the use of a single-dose antifungal prophylaxis administered in the operating room but none subsequently does not result in an increased incidence of IFI following pancreas transplantation.

Simultaneous Heart-kidney Transplant With Planned Delayed Implantation of the Kidney Graft After Ex Vivo Perfusion.

BACKGROUND: Simultaneous heart-kidney transplant (SHK) is an established option for patients with severe heart failure and chronic kidney disease. Recent studies in simultaneous liver-kidney transplantation demonstrate favorable outcomes achieved by delaying implantation of the kidney for over 24 h. This report describes a case series of consecutive patients listed for SHK who had planned delayed implantation of the kidney graft. METHODS: This case series represents a retrospective analysis of SHK patients extracted from the transplant database at a single center. RESULTS: There were 7 patients who underwent SHK during the study period. In all cases, kidney grafts were maintained on hypothermic ex vivo pulsatile perfusion for delayed implantation (mean cold ischemia 53 h [range, 31-69]). The first 5 patients had 100% 1-y heart and kidney graft survival with good function. Patient 6 was unstable on extracorporeal membrane oxygenation post-heart transplant. The kidney was implanted at 69 h, and the patient died soon thereafter. Patient 7 was also unstable on extracorporeal membrane oxygenation after heart transplant. The decision was made to implant the kidney into a backup kidney recipient. The heart transplant recipient subsequently died several days later, whereas the kidney was successfully transplanted in the alternate candidate. CONCLUSIONS: This case series highlights the potential utility of delayed kidney implantation in SHK patients. SHK with delayed renal transplant may provide an improved physiologic environment for renal transplant, which may result in improved early renal graft function. Delayed kidney transplant also provides the opportunity to transplant the kidney graft into an alternate candidate.

Implementation of Clinical Cytochrome P450 3A Genotyping for Tacrolimus Dosing in a Large Kidney Transplant Program.

Tacrolimus is a calcineurin inhibitor with a narrow therapeutic range and is metabolized by cytochrome P450 (CYP) isoenzymes CYP3A4 and CYP3A5. The Clinical Pharmacogenetic Implementation Consortium published evidence-based guidelines for CYP3A5 normal/intermediate metabolizers prescribed tacrolimus, yet few transplant centers have implemented routine testing. The objective of this study was to implement preemptive CYP3A genotyping into clinical practice in a large kidney transplant program and to evaluate workflow feasibility, potential clinical benefit, and reimbursement to identify barriers and determine sustainability. Preemptive pharmacogenetic testing for CYP3A5 and CYP3A4 was implemented in all patients listed for a kidney transplant as part of standard clinical care. Genotyping was performed at the listing appointment, results were reported as discrete data in the electronic medical record, and education and clinical decision support alerts were developed to provide pharmacogenetic-recommended tacrolimus dosing. During this initial phase, all patients were administered standard tacrolimus dosing, and clinical and reimbursement outcomes were collected. Greater than 99.5% of genotyping claims were reimbursed by third-party payers. CYP3A5 normal/intermediate metabolizers had significantly fewer tacrolimus trough concentrations within the target range and a significantly longer time to their first therapeutic trough compared to poor metabolizers. The challenge of tacrolimus dosing is magnified in the African American population. The US Food and Drug Administration drug label recommends increased starting doses in African ancestry, yet only ≈66% of African Americans in our cohort were normal/intermediate metabolizers who required higher doses. Routine CYP3A5 genotyping may overcome this issue by using genotype over race as a more accurate predictor of drug response.

Genetic evaluation of living kidney donor candidates: A review and recommendations for best practices.

The growing accessibility and falling costs of genetic sequencing techniques has expanded the utilization of genetic testing in clinical practice. For living kidney donation, genetic evaluation has been increasingly used to identify genetic kidney disease in potential candidates, especially in those of younger ages. However, genetic testing on asymptomatic living kidney donors remains fraught with many challenges and uncertainties. Not all transplant practitioners are aware of the limitations of genetic testing, are comfortable with selecting testing methods, comprehending test results, or providing counsel, and many do not have access to a renal genetic counselor or a clinical geneticist. Although genetic testing can be a valuable tool in living kidney donor evaluation, its overall benefit in donor evaluation has not been demonstrated and it can also lead to confusion, inappropriate donor exclusion, or misleading reassurance. Until more published data become available, this practice resource should provide guidance for centers and transplant practitioners on the responsible use of genetic testing in the evaluation of living kidney donor candidates.

Factors enabling transplant program participation in the Scientific Registry of Transplant Recipients (SRTR) Living Donor Collective: A national survey.

BACKGROUND: The Scientific Registry of Transplant Recipients (SRTR) Living Donor Collective (LDC), the first effort to create a lifetime registry for living donor candidates in the United States, requires transplant programs to register donor candidates while the SRTR conducts follow-up. METHODS: To better understand facilitators and barriers to program participation, we conducted a brief electronic survey of U.S. transplant program staff from October 26, 2021 to December 17, 2021. RESULTS: We received 132 responses, with at least one response from 87 living donor programs (46 kidney programs, 33 kidney and liver programs, and eight liver programs alone). We found 86% of program representatives strongly agreed or agreed that funding adequate to cover the cost of data collection would facilitate LDC participation, 92% agreed or strongly agreed with importance of electronic data submission options, and 74% reported that elimination of requirements to submit duplicative pre-operative information to the Organ Procurement and Transplantation Network (OPTN) would be helpful. Other potentially enabling factors include reduction in duration of OPTN postdonation follow-up requirements, ease-of-use, protection from data use for regulation, adequate data security, and equity in data access. CONCLUSION: This survey identifies potential targets to strengthen participation in the effort to create a national living donor registry in the United States. Collaboration and investment to overcome barriers to LDC participation among transplant programs are vital to generate long-term data on living donation for donor candidates, donors, and patients in need of transplant.

Vasopressin for Post-kidney Transplant Hypotension.

Introduction: Hypotension after deceased donor kidney transplant (DDKT) is a risk factor for delayed graft function (DGF) and poor graft survival (GS). We hypothesize that vasopressin use in hypotensive DDKT recipients (DDKTRs) to increase blood pressure (BP) reduces DGF rates and is safe without increasing mortality. Methods: Group with vasopressin "study group" (n = 45) was defined as DDKTRs between 2012 and 2017 who required vasopressin for hypotension systolic BP (SBP) <120 mm Hg or diastolic BP (DBP) <60 mm Hg. DDKTRs with no-vasopressin "comparison group" (n = 90) were propensity score-matched DDKTRs between 2012 and 2017 without vasopressin use. Primary outcomes were GS, creatinine and allograft biopsy rate at 1 year, DGF rate, and death during transplant hospitalization. Results: Vasopressin group had lower mean maximum and minimum SBP and DBP in the operating room (OR). Median vasopressin start time post-DDKT was 2 hours (interquartile range [IQR] 1-6), and duration of use was 42 hours (IQR 24-63). DGF, creatinine at 1 year, and allograft biopsy rates were comparable. No deaths occurred during transplant hospitalization. Multivariable analysis did not find an effect of vasopressin use on GS. Conclusion: Treatment of hypotensive DDKTRs with vasopressin is safe and facilitated similar graft function and survival with that of nonhypotensive patients. In the absence of a randomized control trial, our study supports the safety of vasopressin therapy to prevent the adverse effects of hypotension.

Nondirected Living Kidney Donation and Recipient Outcomes in the United States: A 20-Year Review.

Introduction: Nondirected donation (NDD) of the kidneys is a growing practice where donors who do not have any genetic or emotional relationship are selected to donate to a wide variety of recipients with a range of selection criteria and decisions which are left up to individual transplant centers. Methods: We review all adult living kidney donor-recipient (DR) pairs and outcomes from NDDs who were recorded in United Network for Organ Sharing (UNOS) database as code 10 (anonymous) from October 1997 to September 2017 for demographics and outcomes. Results: A total of 2174 DR pairs were identified. The number of NDDs increased from 18 in 2000 to 256 in 2016. Survival analysis showed higher death-censored-graft survival (DC-GS) when recipient was 20 years or more older than donor followed by recipient-donor within 20 years of age and lowest when donor was 20 years or more older than recipient (P = 0.0114). Conclusion: Overall, the number of NDDs has increased significantly in the 20-year review period. Transplants from NDDs have excellent long-term outcomes. Better matching of controllable DR factors, such as age and body mass index (BMI), could further improve GS. Further research is needed to incorporate these DR factors into paired kidney donation programs potentially enhancing the utility and beneficence of this invaluable donation.

Telemedicine services for living kidney donation: A US survey of multidisciplinary providers.

Individuals considering living kidney donation face geographic, financial, and logistical challenges. Telemedicine can facilitate healthcare access/care coordination. Yet difficulties exist in telemedicine implementation and sustainability. We sought to examine centers' practices and providers' attitudes toward telemedicine to improve services for donors. We surveyed multidisciplinary providers from 194 active adult US living donor kidney transplant centers; 293 providers from 128 unique centers responded to the survey (center representation rate = 66.0%), reflecting 83.9% of practice by donor volume and 91.5% of US states/territories. Most centers (70.3%) plan to continue using telemedicine beyond the pandemic for donor evaluation/follow-up. Video was mostly used by nephrologists, surgeons, and psychiatrists/psychologists. Telephone and video were mostly used by social workers, while video or telephone was equally used by coordinators. Half of respondent nephrologists and surgeons were willing to accept a remote completion of physical exam; 68.3% of respondent psychiatrists/psychologists and social workers were willing to accept a remote completion of mental status exam. Providers strongly agreed that telemedicine was convenient for donors and would improve the likelihood of completing donor evaluation. However, providers (65.5%) perceived out-of-state licensing as a key policy/regulatory barrier. These findings help inform practice and underscore the instigation of policies to remove barriers using telemedicine to increase living kidney donation.

Patient and Graft Survival Outcomes During 2 Eras of Immunosuppression Protocols in Kidney Transplantation: Indiana University Retrospective Cohort Experience.

BACKGROUND: Since 1964 when Indiana University performed its first kidney transplant, immunosuppression protocol was steroid-based until 2004 when steroid-free immunosuppression protocol was adopted. We describe clinical outcomes on our patients administered early steroid withdrawal (ESW) protocol (5 days) compared with our historical cohort (HC), who were on chronic steroid-based immunosuppression. METHODS: We performed a retrospective study evaluating kidney transplant recipients between 1993 and 2003 (HC, n = 1689) and between 2005 and 2016 (ESW cohort, n = 2097) at the Indiana University program, with a median follow-up of 10.5 years and 6.1 years, respectively. Primary outcomes were patient and death-censored graft survival at 1, 3, and 5 years in both study cohorts. Secondary outcomes were 1-year rates of biopsy-proven acute rejection; graft function at 1, 3, and 5 years; and risk of post-transplant infection (BK virus and cytomegalovirus) in the ESW cohort. Cox proportional model and Kaplan-Meier estimates were used to estimate survival probabilities. Fisher exact tests were used to compare episodes of acute rejection in the ESW cohort. RESULTS: No difference was observed in patient survival between the ESW and HC cohorts (P = .13). Compared with the ESW cohort, death-censored graft survival was significantly worse in the HC (5 year: 86.4% vs 90.6%, log-rank P < .001). One-year acute rejection reported in the ESW cohort alone was 15.7% and significantly worse in Black patients and younger patients (P < .05). CONCLUSIONS: In this sizeable single-center cohort study with significant ethnic diversity, ESW is a viable alternative to steroid-based immunosuppression protocol in kidney transplant recipients.

Procedure: Laparoscopic Donor Nephrectomy.

Minimally invasive approaches for laparoscopic donor nephrectomy are necessary to limit surgical morbidity, and technical challenges differ from those encountered during other laparoscopic renal surgeries. Presented here is a step-by-step guide for laparoscopic donor nephrectomy-focusing on pure laparoscopic and hand-assisted techniques. Both straight laparoscopic and hand-assisted nephrectomies were performed in healthy donors who met transplantation criteria in terms of global health and psychologic well-being. Patient positioning, trocar placement, surgical steps, incision closure, and postoperative care are reviewed. Standard equipment used to complete this procedure is itemized. This guide outlines indications, preoperative preparation, and procedural steps for laparoscopic donor nephrectomy. The techniques and the evolution thereof represent our experience since 2002 for 510 cases. The attached videos demonstrate a high-volume surgeon's typical approach while factoring in anatomical variation. In both cases, the donor nephrectomies were without incident and the patient's postoperative courses were without complication. A basic framework for donor nephrectomy is presented highlighting surgical steps we believe to be essential for graft preservation and ultimately effective transplantation. Although no two cases are the same, systematic approaches will allow for timely case completion, fewer complications, and better donor/recipient outcomes.

Operational challenges in the COVID-19 era: Asymptomatic infections and vaccination timing.

The coronavirus disease 2019 (COVID-19) pandemic has created unprecedented challenges for solid organ transplant programs. While transplant activity has largely recovered, appropriate management of deceased donor candidates who are asymptomatic but have positive nucleic acid testing (NAT) for SARS-CoV-2 is unclear, as this result may reflect active infection or prolonged viral shedding. Furthermore, candidates who are unvaccinated or partially vaccinated continue to receive donor offers. In the absence of robust outcomes data, transplant professionals at US adult kidney transplant centers were surveyed (February 13, 2021 to April 29, 2021) to determine community practice (N: 92 centers, capturing 41% of centers and 57% of transplants performed). The majority (97%) of responding centers declined organs for asymptomatic NAT+ patients without documented prior infection. However, 32% of centers proceed with kidney transplant in NAT+ patients who were at least 30 days from initial diagnosis with negative chest imaging. Less than 7% of programs reported inactivating patients who were unvaccinated or partially vaccinated. In conclusion, despite national recommendations to wait for negative testing, many centers are proceeding with kidney transplant in patients with positive SARS-CoV-2 NAT results due to presumed viral shedding. Furthermore, few centers are requiring COVID-19 vaccination prior to transplantation at this time.

A National Survey of Practice Patterns for Accepting Living Kidney Donors With Prior COVID-19.

INTRODUCTION: A critical question facing transplant programs is whether, when, and how to safely accept living kidney donors (LKDs) who have recovered from COVID-19 infection. The purpose of the study is to understand current practices related to accepting these LKDs. METHODS: We surveyed US transplant programs from 3 September through 3 November 2020. Center level and participant level responses were analyzed. RESULTS: A total of 174 respondents from 115 unique centers responded, representing 59% of US LKD programs and 72.4% of 2019 and 72.5% of 2020 LKD volume (Organ Procurement and Transplantation Network-OPTN 2021). In all, 48.6% of responding centers had received inquiries from such LKDs, whereas 44.3% were currently evaluating. A total of 98 donors were in the evaluation phase, whereas 27.8% centers had approved 42 such donors to proceed with donation. A total of 50.8% of participants preferred to wait >3 months, and 91% would wait at least 1 month from onset of infection to LD surgery. The most common reason to exclude LDs was evidence of COVID-19-related AKI (59.8%) even if resolved, followed by COVID-19-related pneumonia (28.7%) and hospitalization (21.3%). The most common concern in accepting such donors was kidney health postdonation (59.2%), followed by risk of transmission to the recipient (55.7%), donor perioperative pulmonary risk (41.4%), and donor pulmonary risk in the future (29.9%). CONCLUSION: Practice patterns for acceptance of COVID-19-recovered LKDs showed considerable variability. Ongoing research and consensus building are needed to guide optimal practices to ensure safety of accepting such donors. Long-term close follow-up of such donors is warranted.

Living Donor Gifted Lithiasis: Long-Term Outcomes in Recipients.

OBJECTIVES: Presence of nephrolithiasis in a living donor has been at least a relative contraindication to living donor nephrectomy. The concern for stone recurrence and outcomes has been one of the reasons for reluctance to consider these medically complex donors. We evaluate long-term outcomes in recipients of kidney grafts from donors with nephrolithiasis, or history of nephrolithiasis, and provide results from our experience at Indiana University. MATERIALS AND METHODS: We retrospectively reviewed 57 donor-recipient pairs, where the allograft was received from a living donor with symptomatic calculi, or with imaging evidence of kidney stones, between 2003 and 2018. This research study was done in compliance with the ethical standards set forth in the Helsinki Congress. RESULTS: The mean age of recipients was 46±19 years and 58% were male. Kidney recipients were followed for a median of 3.5 years and 59.6% of patients had follow-up imaging studies. None of the recipients had obstructing renal calculi or related infections. None of the recipients required any interventions for recurrent calculi and no stone episode lead to adverse event to the graft. Hyperoxaluria and hypercalciuria were the most common risk factors in 24-hour urine collections obtained from donors. CONCLUSIONS: Our findings from a single large center looking at kidney recipient outcomes over a long follow-up period found that gifted lithiasis is a safe procedure. Careful selection of "medically complex donors" with kidney stones based on appropriate guidelines is a key step. Further studies are needed to help develop consensus guidelines.

Survey of US Living Kidney Donation and Transplantation Practices in the COVID-19 Era.

INTRODUCTION: The scope of the impact of the coronavirus disease 2019 (COVID-19) pandemic on living donor kidney transplantation (LDKT) practices is not well defined. METHODS: We surveyed US transplant programs to assess practices, strategies, and barriers to living LDKT during the COVID-19 pandemic. After institutional review board approval, the survey was distributed from 9 May 2020 to 30 May 2020 by e-mail and postings to professional society list-servs. Responses were stratified based on state COVID-19 cumulative incidence levels. RESULTS: Staff at 118 unique centers responded, representing 61% of US living donor recovery programs and 75% of LKDT volume in the prepandemic year. Overall, 66% reported that LDKT surgery was on hold (81% in "high" vs. 49% in "low" COVID-19 cumulative incidence states). A total of 36% reported that evaluation of new donor candidates had paused, 27% reported that evaluations were very much decreased (>0% to <25% typical), and 23% reported that evaluations were moderately decreased (25% to <50% typical). Barriers to LDKT surgery included program concerns for donor (85%) and recipient (75%) safety, patient concerns (56%), elective case restrictions (47%), and hospital administrative restrictions (48%). Programs with higher local COVID-19 cumulative incidence reported more barriers related to staff and resource diversion. Most centers continuing donor evaluations used remote strategies (video, 82%; telephone, 43%). As LDKT resumes, all programs will screen for COVID-19, although timeframe and modalities will vary. Recommendations for presurgical self-quarantine are also variable. CONCLUSION: The COVID-19 pandemic has had broad impacts on LDKT practice. Ongoing research and consensus building are needed to reduce barriers, to guide optimal practices, and to support safe restoration of LDKT across centers.

Implementation of a Renal Precision Medicine Program: Clinician Attitudes and Acceptance.

A precision health initiative was implemented across a multi-hospital health system, wherein a panel of genetic variants was tested and utilized in the clinical care of chronic kidney disease (CKD) patients. Pharmacogenomic predictors of antihypertensive response and genomic predictors of CKD were provided to clinicians caring for nephrology patients. To assess clinician knowledge, attitudes, and willingness to act on genetic testing results, a Likert-scale survey was sent to and self-administered by these nephrology providers (N = 76). Most respondents agreed that utilizing pharmacogenomic-guided antihypertensive prescribing is valuable (4.0 ± 0.7 on a scale of 1 to 5, where 5 indicates strong agreement). However, the respondents also expressed reluctance to use genetic testing for CKD risk stratification due to a perceived lack of supporting evidence (3.2 ± 0.9). Exploratory sub-group analyses associated this reluctance with negative responses to both knowledge and attitude discipline questions, thus suggesting reduced exposure to and comfort with genetic information. Given the evolving nature of genomic implementation in clinical care, further education is warranted to help overcome these perception barriers.

Correlation and Prediction of Living-Donor Remaining Function by Using Predonation Computed Tomography-Based Volumetric Measurements: Role of Remaining Kidney Volume.

OBJECTIVES: Kidney volume in healthy living donors may serve as a surrogate marker of renal function. Here, we evaluated whether preserved kidney volume correlated with and could predict donor renal function at 2 years postdonation using the CKD-EPI estimated glomerular filtration rate equation. MATERIALS AND METHODS: Healthy living donors (n = 208) with computed tomography volume measurements were evaluated for renal function before and after donation. Preserved kidney volume was adjusted to body surface area. Demographic characteristics (including race/ethnicity and sex) and renal function variables of donors were analyzed for postdonation renal function. RESULTS: Donor mean age was 39.4 ± 10.7 years (36.2% males, 91.9% white). Median adjusted preserved kidney volume was 180.6 mL. At 2 years postdonation, median estimated glomerular filtration rate was 62.4 mL/min (interquartile range, 54.8-73.2 mL/min). Predonation estimated glomerular filtration rate, age, and adjusted preserved kidney volume were found to be inde-pendent predictors of 2-year estimated glomerular filtration rate (P < .001). We further analyzed data by stratifying preserved kidney volumes into tertiles. Mean 2-year estimated glomerular filtration rates were 57.9 ± 12, 65 ± 16, and 73 ± 17 mL/min for lowest to highest tertile groups, respectively (P < .05). The odds ratio of having a 2-year postdonation estimated glomerular filtration rate of < 60 mL/min for donors in the lowest tertile group was 3.51 (95% confidence interval, 1.9-6.4; P < .001), whereas the risk for donors in the highest tertile group was 0.23 (95% confidence interval, 0.12-0.44; P< .001). Sensitivity analysis result was 0.764 (95% confidence interval, 0.69-0.82; P = .005) for adjusted preserved kidney volume and estimated glomerular filtration rate of < 60 mL/min. CONCLUSIONS: Remaining kidney volume before donation correlated with and predicted estimated glomerular filtration rate after donation. Remaining kidney volume should be assessed when selecting kidneys from healthy donors.