A2/A2B to B deceased donor kidney transplantation in the Kidney Allocation System era.

Kidney transplantation from blood type A2/A2B donors to type B recipients (A2→B) has increased dramatically under the current Kidney Allocation System (KAS). Among living donor transplant recipients, A2-incompatible transplants are associated with an increased risk of all-cause and death-censored graft failure. In light of this, we used data from the Scientific Registry of Transplant Recipients from December 2014 until June 2022 to evaluate the association between A2→B listing and time to deceased donor kidney transplantation (DDKT) and post-DDKT outcomes for A2→B recipients. Among 53 409 type B waitlist registrants, only 12.6% were listed as eligible to accept A2→B offers ("A2-eligible"). The rates of DDKT at 1-, 3-, and 5-years were 32.1%, 61.4%, and 72.1% among A2-eligible candidates and 14.1%, 29.9%, and 44.1% among A2-ineligible candidates, with the former experiencing a 133% higher rate of DDKT (Cox weighted hazard ratio (wHR) = 2.192.332.47; P < .001). The 7-year adjusted mortality was comparable between A2→B and B-ABOc (type B/O donors to B recipients) recipients (wHR 0.780.941.13, P = .5). Moreover, there was no difference between A2→B vs B-ABOc DDKT recipients with regards to death-censored graft failure (wHR 0.771.001.29, P > .9) or all-cause graft loss (wHR 0.820.961.12, P = .6). Following its broader adoption since the implementation of the kidney allocation system, A2→B DDKT appears to be a safe and effective transplant modality for eligible candidates. As such, A2→B listing for eligible type B candidates should be expanded.

Patient and Graft Survival After A1/A2-incompatible Living Donor Kidney Transplantation.

ABO type B and O kidney transplant candidates have increased difficulty identifying a compatible donor for living donor kidney transplantation (LDKT) and are harder to match in kidney paired donation registries. A2-incompatible (A2i) LDKT increases access to LDKT for these patients. To better inform living donor selection, we evaluated the association between A2i LDKT and patient and graft survival. Methods: We used weighted Cox regression to compare mortality, death-censored graft failure, and all-cause graft loss in A2i versus ABO-compatible (ABOc) recipients. Results: Using Scientific Registry of Transplant Recipients data 2000-2019, we identified 345 A2i LDKT recipients. Mortality was comparable among A2i and ABOc recipients; weighted 1-/5-/10-y mortality was 0.9%/6.5%/24.2%, respectively, among A2i LDKT recipients versus 1.4%/7.7%/22.2%, respectively, among ABOc LDKT recipients (weighted hazard ratio [wHR], 0.811.041.33; P = 0.8). However, A2i recipients faced higher risk of death-censored graft failure; weighted 1-/5-/10-y graft failure was 5.7%/11.6%/22.4% for A2i versus 1.7%/7.5%/17.2% for ABOc recipients (wHR in year 1 = 2.243.565.66; through year 5 = 1.251.782.53; through year 10 = 1.151.552.07). By comparison, 1-/5-/10-y wHRs for A1-incompatible recipients were 0.631.966.08/0.390.942.27/0.390.831.74. Conclusions: A2i LDKT is generally safe, but A2i donor/recipient pairs should be counseled about the increased risk of graft failure and be monitored as closely as their A1-incompatible counterparts posttransplant.

The Tangible Benefits of Living Donation: Results of a Qualitative Study of Living Kidney Donors.

The framework currently used for living kidney donor selection is based on estimation of acceptable donor risk, under the premise that benefits are only experienced by the recipient. However, some interdependent donors might experience tangible benefits from donation that cannot be considered in the current framework (ie, benefits experienced directly by the donor that improve their daily life, well-being, or livelihood). METHODS: We conducted semistructured interviews with 56 living kidney donors regarding benefits experienced from donation. Using a qualitative descriptive and constant comparative approach, themes were derived inductively from interview transcripts by 2 independent coders; differences in coding were reconciled by consensus. RESULTS: Of 56 participants, 30 were in interdependent relationships with their recipients (shared household and/or significant caregiving responsibilities). Tangible benefits identified by participants fell into 3 major categories: health and wellness benefits, time and financial benefits, and interpersonal benefits. Participants described motivations to donate a kidney based on a more nuanced understanding of the benefits of donation than accounted for by the current "acceptable risk" paradigm. DISCUSSION: Tangible benefits for interdependent donors may shift the "acceptable risk" paradigm (where no benefit is assumed) of kidney donor evaluation to a risk/benefit paradigm more consistent with other surgical decision-making.

Evolving Impact of COVID-19 on Transplant Center Practices and Policies in the United States.

In our first survey of transplant centers in March 2020, >75% of kidney and liver programs were either suspended or operating under restrictions. To safely resume transplantation, we must understand the evolving impact of COVID-19 on transplant recipients and center-level practices. We therefore conducted a six-week follow-up survey May 7-15, 2020, and linked responses to the COVID-19 incidence map, with a response rate of 84%. Suspension of live donor transplantation decreased from 72% in March to 30% in May for kidneys and from 68% to 52% for livers. Restrictions/suspension of deceased donor transplantation decreased from 84% to 58% for kidneys and from 73% to 42% for livers. Resuming transplantation at normal capacity was envisioned by 83% of programs by August 2020. Exclusively using local recovery teams for deceased donor procurement was reported by 28%. Respondents reported caring for a total of 1166 COVID-19-positive transplant recipients; 25% were critically ill. Telemedicine challenges were reported by 81%. There was a lack of consensus regarding management of potential living donors or candidates with SARS-CoV-2. Our findings demonstrate persistent heterogeneity in center-level response to COVID-19 even as transplant activity resumes, making ongoing national data collection and real-time analysis critical to inform best practices.

Early impact of COVID-19 on transplant center practices and policies in the United States.

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

Association of Early Postdonation Renal Function With Subsequent Risk of End-Stage Renal Disease in Living Kidney Donors.

Importance: Living kidney donation is associated with increased long-term risk of end-stage renal disease (ESRD). An early postdonation marker of ESRD risk could improve postdonation risk assessment and counseling for kidney donors and allow early intervention for donors at increased risk. Objective: To determine the association between renal function in the first 6 months postdonation and subsequent risk of ESRD in kidney donors. Design, Setting, and Participants: This secondary analysis of a prospective national cohort uses a population-based registry of all living kidney donors in the United States between October 26, 1999, and January 1, 2018, with follow-up through December 31, 2018. All kidney donors who had donated in the date range and had serum creatinine measured at 6 months (±3 months) postdonation were included. Exposures: Renal function as measured by estimated glomerular filtration rate 6 months after donation (eGFR6). Main Outcomes and Measures: End-stage renal disease, ascertained via linkage to Centers for Medicare & Medicaid Services data. Results: A total of 71 468 living kidney donors were included (of 109 065 total donors over this period). Their median (interquartile range) eGFR6 was 63 (54-74) mL/min/1.73 m2. Cumulative incidence of ESRD at 15 years postdonation ranged from 11.7 donors per 10 000 donors with eGFR6 values greater than 70 mL/min/1.73 m2 to 33.1 donors per 10 000 donors with eGFR6 values of 50 mL/min/1.73 m2 or less. Adjusting for age, race, sex, body mass index, and biological relationship, every 10 mL/min/1.73 m2 reduction in eGFR6 was associated with a 28% increased risk of ESRD (adjusted hazard ratio, 1.28 [95% CI, 1.06-1.54]; P = .009). The association between predonation eGFR and ESRD was not significant and was fully mediated by eGFR6 (adjusted hazard ratio, 1.00 [95% CI, 0.86-1.17]; P = .97). The postdonation eGFR value was a better marker of ESRD than eGFR decline after donation or the ratio of eGFR6 to predonation eGFR, as determined by the Akaike information criterion (in which a lower value indicates a better model fit; eGFR6, 1495.61; predonation eGFR - eGFR6, 1503.58; eGFR6 / predonation eGFR, 1502.30). Conclusions and Relevance: In this study, there was an independent association of eGFR6 with subsequent ESRD risk in living kidney donors, even after adjusting for predonation characteristics. The findings support measurement of early postdonation serum creatinine monitoring in living kidney donors, and the use of these data to help identify donors who might need more careful surveillance and early intervention.