Faculty Bibliography

IMPORTANCE:The proportion of living donor kidney transplants from donors unrelated to their recipients is increasing in the US. OBJECTIVE:To examine the association between donor-recipient biological relationship and allograft survival after living donor kidney transplant. DESIGN, SETTING, AND PARTICIPANTS:This retrospective cohort study used Organ Procurement and Transplantation Network data on US adult living donor kidney transplants (n = 86 154) performed from January 1, 2000, to December 31, 2014, excluding cases in which recipients previously received a kidney transplant (n = 10 342) or key data were missing (n = 2832). Last follow-up was March 20, 2020. EXPOSURES:Donor-recipient biological relationship. MAIN OUTCOMES AND MEASURES:The primary outcome was death-censored allograft failure. Univariate and multivariable time-to-event analyses were performed for death-censored allograft failure for the overall cohort, then separately for recipients with and without primary diagnoses of cystic kidney disease and for transplants from African American and non-African American donors. RESULTS:Among the 72 980 transplant donor and recipients included in the study (median donor age, 41 years; interquartile range [IQR], 32-50 years; 43 990 [60%] female; 50 014 [69%] White), 43 174 (59%) donors and recipients were biologically related and 29 806 (41%) were unrelated. Donors related to their recipients were younger (median [IQR] age, 39 [31-48] vs 44 [35-52] years) and less likely to be female (24 848 [58%] vs 19 142 [64%]) or White (26 933 [62%] vs 23 081 [77%]). Recipients related to their donors were younger (median [IQR] age, 48 [34-58] vs 50 [40-58] years), more likely to be female (18 035 [42%] vs 10 530 [35%]), and less likely to have cystic kidney disease (2530 [6%] vs 4600 [15%]). Related pairs had fewer HLA mismatches overall (median [IQR], 3 [2-3] vs 5 [4-5]). After adjustment for HLA mismatches, donor and recipient characteristics, and transplant era, donor-recipient biological relationship was associated with higher death-censored allograft failure (hazard ratio, 1.05; 95% CI, 1.01-1.10; P = .03). When stratified by primary disease, this association persisted only for recipients without cystic kidney disease. When stratified by donor race, this association persisted only for transplants from African American donors. CONCLUSIONS AND RELEVANCE:In this cohort study, living donor kidney transplants from donors biologically related to their recipients had higher rates of allograft failure than transplants from donors unrelated to their recipients after HLA matching was accounted for. Further study is needed to determine which genetic or socioenvironmental factors are associated with this finding.

Kidney replacement therapy is required in up to one-third of patients after left ventricular assist device (LVAD) placement. A subset of these patients requires long-term maintenance hemodialysis and therefore needs durable vascular access but the ideal access in such patients has not been established. We present a series of 3 patients in whom arteriovenous grafts (AVGs) were successfully used for long-term kidney replacement therapy after LVAD placement. The maximum time from AVG placement to first successful AVG use was 40 days, and the longest AVG use duration was more than 2 years. 2 patients required AVG excision due to infection but both had successful placement of a second AVG. Total time on kidney replacement therapy was 993, 1,055, and 956 days for the 3 cases, of which dialysis catheter use was required for only 23%, 6.5%, and 27%, respectively. These cases suggest that AVG placement is a viable option for dialysis access in patients with LVADs.

There are limited data on the nonprocurement of kidneys from solid organ donors. Analysis of Standard Transplant Analysis and Research files was undertaken on all deceased donors in the United States with at least 1 solid organ recovered. From 2000 to 2018, 21 731 deceased donor kidneys (averaging 1144 kidneys per year) were not procured. No kidneys were procured from 8% of liver donors, 3% of heart donors, and 3% of lung donors. Compared to donors with all kidneys procured, those with none procured were older and more likely obese, black, hypertensive, diabetic, hepatitis C positive, smokers, Public Health Service - Increased Risk designated, deceased after cardiac death, or deceased after cerebrovascular accident. Although these donors had lower quality kidneys (median Kidney Donor Risk Index (interquartile range) 1.9 (1.0) vs 1.2 (0.7)), there was substantial overlap in quality between nonprocured and procured kidneys. Nearly one third of nonprocurements were attributed to donor history. Donors with elevated terminal creatinine likely resulting from acute kidney injury (AKI) had higher odds of kidney nonprocurement. Nonprocurement odds varied widely across Organ Procurement and Transplantation Network regions, with a positive correlation between donor kidney nonprocurements and kidney discards at the donation service area level. These findings suggest current discard rates underestimate the underutilization of deceased donor kidneys and more research is needed to optimize safe procurement and utilization of kidneys from donors with AKI.

Coronavirus disease 2019 (COVID-19) has become a pandemic since first being described in January 2020. Clinical manifestations in non-transplant patients range from asymptomatic infection to severe pneumonia with acute respiratory distress syndrome, multiorgan system failure, and death. Limited reports in kidney transplant recipients suggest similar characteristics in that population. We report here the first case series of COVID-19 infection occurring in pancreas transplant recipients.

BACKGROUND:Geographic disparities in access to deceased donor kidney transplantation persist in the United States under the Kidney Allocation System (KAS) introduced in 2014, and the effect of transplant center practices on the probability of transplantation for wait-listed patients remains unclear. METHODS:To compare probability of transplantation across centers nationally and within donation service areas (DSAs), we conducted a registry study that included all United States incident adult kidney transplant candidates wait listed in 2011 and 2015 (pre-KAS and post-KAS cohorts comprising 32,745 and 34,728 individuals, respectively). For each center, we calculated the probability of deceased donor kidney transplantation within 3 years of wait listing using competing risk regression, with living donor transplantation, death, and waiting list removal as competing events. We examined associations between center-level and DSA-level characteristics and the adjusted probability of transplant. RESULTS:<0.001). CONCLUSIONS:Large differences in the adjusted probability of deceased donor kidney transplantation persist under KAS, even between centers working with the same local organ supply. Probability of transplantation is significantly associated with organ offer acceptance patterns at transplant centers, underscoring the need for greater understanding of how centers make decisions about organs offered to wait-listed patients and how they relate to disparities in access to transplantation.

The safety and efficacy of tocilizumab for the treatment of severe respiratory symptoms due to COVID-19 remain uncertain, in particular among solid organ transplant (SOT) recipients. Thus, we evaluated the clinical characteristics and outcomes of 29 hospitalized SOT recipients who received tocilizumab for severe COVID-19, compared to a matched control group who did not. Among a total of 117 total SOT recipients hospitalized with COVID-19, 29 (24.8%) received tocilizumab. The 90-day mortality was significantly higher among patients who received tocilizumab (41%) compared to those who did not (20%, P = .03). When compared to control patients matched by age, hypertension, chronic kidney disease, and administration of high dose corticosteroids, there was no significant difference in mortality (41% vs 28%, P = .27), hospital discharge (52% vs 72%, P = .26), or secondary infections (34% vs 24%, P = .55). Among patients who received tocilizumab, there was also no difference in mortality based on the level of oxygen support (intubated vs not intubated) at the time of tocilizumab initiation. In this matched cohort study, tocilizumab appeared to be safe but was not associated with decreased 90-day mortality. Larger randomized studies are needed to identify whether there are subsets of SOT recipients who may benefit from tocilizumab for treatment of COVID-19.