The Impact of the New Kidney Allocation System on Prior Living Kidney Donors' Access to Deceased Donor Kidney Transplants: An Early Look.

This study investigated the early effects of the new kidney allocation system (KAS) on the access of prior living kidney donors (PLDs) to deceased donor kidney transplants. Using data from the Organ Procurement and Transplantation Network, we compared prevalent and incident cohorts of PLDs in the 1-year periods before and after KAS implementation (pre-KAS group: December 4, 2013, to December 3, 2014, n = 50 [newly listed PLDs]; post-KAS group: December 4, 2014, to December 3, 2015, n = 39). We assessed transplant rates per active patient-year, waiting times, and Kidney Donor Profile Index (KDPI) of transplanted kidneys. Transplant rates were not statistically different before and after KAS implementation for either prevalent (2.37 vs. 2.29, relative risk [RR] 0.96; 95% confidence interval [CI] 0.62-1.49) or incident (4.76 vs. 4.36, RR 0.92; 95% CI 0.53-1.60) candidates. Median waiting time (MWT) to deceased donor kidney transplant for prevalent PLDs in the post-KAS cohort was 102.6 days compared with 82.3 days in the pre-KAS cohort (p = 0.98). The median KDPI for PLD recipients was 31% with KAS versus 23% before KAS (p = 0.02). Despite a sharp decrease in the MWT for highly prioritized candidates with calculated panel reactive antibodies of 98-100% (from >7000 to 1164 days), PLDs still had much shorter waiting times (MWT 102.6 days). The new system continues to provide quick access to high-quality organs for PLDs.

Changes in Deceased Donor Kidney Transplantation One Year After KAS Implementation.

After over a decade of discussion, analysis, and consensus-building, a new kidney allocation system (KAS) was implemented on December 4, 2014. Key goals included improving longevity matching between donor kidneys and recipients and broadening access for historically disadvantaged subpopulations, in particular highly sensitized patients and those with an extended duration on dialysis but delayed referral for transplantation. To evaluate the early impact of KAS, we compared Organ Procurement and Transplantation Network data 1 year before versus after implementation. The distribution of transplants across many recipient characteristics has changed markedly and suggests that in many ways the new policy is achieving its goals. Transplants in which the donor and recipient age differed by more than 30 years declined by 23%. Initial, sharp increases in transplants were observed for Calculated Panel-Reactive Antibody 99-100% recipients and recipients with at least 10 years on dialysis, with a subsequent tapering of transplants to these groups suggesting bolus effects. Although KAS has arguably increased fairness in allocation, the potential costs of broadening access must be considered. Kidneys are more often being shipped over long distances, leading to increased cold ischemic times. Delayed graft function rates have increased, but 6-month graft survival rates have not changed significantly.

Retransplant and Medical Therapy for Cardiac Allograft Vasculopathy: International Society for Heart and Lung Transplantation Registry Analysis.

Cardiac retransplantation for heart transplant recipients with advanced cardiac allograft vasculopathy (CAV) remains controversial. The International Society for Heart and Lung Transplantation Registry was used to examine survival in adult heart recipients with CAV who were retransplanted (ReTx) or managed medically (MM). Recipients transplanted between 1995 and 2010 who developed CAV and were either retransplanted within 2 years of CAV diagnosis (ReTx) or alive at ≥2 years after CAV diagnosis, managed medically (MM), without retransplant, constituted the study groups. Donor, recipient, transplant characteristics and long-term survival were compared. The population included 65 patients in ReTx and 4530 in MM. During a median follow-up of 4 years, there were 24 deaths in ReTx, and 1466 in MM. Survival was comparable at 9 years (55% in ReTx and 51% in MM; p = 0.88). Subgroup comparison suggested survival benefit for retransplant versus MM in patients who developed systolic graft dysfunction. Adjusted predictors for 2-year mortality were diagnosis of CAV in the early era and longer time since CAV diagnosis following primary transplant. Retransplant was not an independent predictor in the model. Challenges associated with retransplantation as well as improved CAV treatment options support the current consensus recommendation limiting retransplant to highly selected patients with CAV.

Calculated PRA: initial results show benefits for sensitized patients and a reduction in positive crossmatches.

The calculated panel reactive antibody (CPRA), which is based upon unacceptable HLA antigens listed on the waitlist form for renal transplant candidates, replaced PRA as the measure of sensitization among US renal transplant candidates on October 1, 2009. An analysis of the impact of this change 6 months after its implementation shows an 83% reduction in the number of kidney offers declined nationwide because of a positive crossmatch. The increasing acceptance and utilization of unacceptable HLA antigens to avoid offers of predictably crossmatch-positive donor kidneys has increased the efficiency of kidney allocation, resulting in a significant increase in the percentage of transplants to broadly sensitized (80+% PRA/CPRA) patients from 7.3% during the period 07/01/2001-6/30/2002 to 15.8% of transplants between 10/1/09-3/31/10. The transplant rates per 1000 active patient-years on the waitlist also increased significantly for broadly sensitized patients after October 1, 2009. These preliminary results suggest that 'virtual' positive crossmatch prediction based on contemporary tools for identifying antibodies directed against HLA antigens is effective, increases allocation efficiency and improves access to transplants for sensitized patients awaiting kidney transplantation.