Potential Association of Blood Transfusion in Deceased Donors With Outcomes of Liver Transplantation in the United States.

BACKGROUND: Donor blood transfusion may potentially affect transplant outcomes through an inflammatory response, recipient sensitization, or transmission of infection. The aim of this study was to evaluate the association of donor blood transfusion with outcomes of liver transplantation (LT). METHODS: From January 2004 to December 2022, donor blood transfusion information was available for 113,017 adult recipients of LT in the United Network for Organ Sharing database and was classified into 4 levels of transfusion: no-transfusion (N = 68,130), transfusion of 1-5 units (N = 33,629), 6-10 units (N = 8067), and >10 units (N = 5329). Recipient survival analysis was performed by Kaplan-Meier method and multivariable Cox-hazard model. RESULTS: Among this cohort, 40.8% of donors (N = 46,261) received blood transfusion during the index hospitalization. Compared to no-blood transfusion donors, blood transfusion donors were younger (median age 37 versus 46 y P < 0.001) and were more brain death donors (94.5% versus 92.1%, P < 0.001). An increased risk of rejection at 6-mo (transfusion 10.3% versus no-transfusion 9.9%, P = 0.055) and 1 y (transfusion 12.5% versus no-transfusion 11.9%, P = 0.0036) post-LT was noted in this cohort. Multivariable Cox-hazard model showed blood transfusion was associated with increased 1-y mortality (transfusion 1.07; 95% CI 1.02-1.12, P = 0.007) and graft failure (transfusion 1.09; 95% CI 1.04-1.13, P < 0.001). CONCLUSIONS: Donor blood transfusion was associated with an increased risk of rejection at 6 mo and 1 y among LT recipients and worse post-transplant graft and overall survival. Additional information regarding donor blood transfusion, along with other known factors, may be considered when deciding the optimization of overall immune suppression in LT recipients to decrease the risk of delayed rejection.

The Effect of New Acuity Circle Policy on Simultaneous Liver and Kidney Transplantation in the United States.

Background: New deceased donor liver allocation policy using an acuity circle (AC)-based model was implemented on February 4th, 2020. The effect of AC policy on simultaneous liver-kidney transplantation (SLKT) remains unknown. The aim of this study was to assess the effect of AC policy on SLKT waitlist mortality, transplant probability, and post-transplant outcomes. Methods: Using the United Network for Organ Sharing database, 4908 adult SLKT candidates during two study periods, pre-AC (Aug-2017 to Feb-2020, N = 2770) and post-AC (Feb-2020 to Dec-2021, N = 2138) were analyzed. Outcomes included 90-day waitlist mortality, transplant probability, and post-transplant patient and graft survival. Results: Compared to pre-AC period, SLKT recipients during post-AC period had higher median model for end-stage liver disease (MELD) score (24 vs 23, P < 0.001), and less percentage of MELD exception (4.6% vs 7.7%, P = 0.001). The 90-day waitlist mortality was same, but the probability of SLKT increased in post-AC period (P < 0.001). Post-AC period also saw increased utilization of donation after cardiac death organs (11% vs 6.4%, P < 0.001) and decreased rates of transplantation among Black candidates (7.9% vs 13%). After risk adjustment, post-AC period was not associated with any significant difference in 90-day waitlist mortality (sub-distribution hazard ratio [sHR] 0.80; 95% CI 0.56-1.16, P = 0.24), and a higher 90-day probability of SLKT (sHR 1.68; 95% CI 1.41-1.99, P < 0.001). During post-transplant period, one-year patient survival, liver and kidney graft survival were comparable between two study periods. Conclusions: The AC liver allocation policy was associated with increased transplant probability of adult SLKT candidates without decreasing waitlist mortality, post-transplant patient survival, or liver and kidney graft survival.

Normothermic Machine Perfusion Is Associated With Improvement in Mortality and Graft Failure in Donation After Cardiac Death Liver Transplant Recipients in the United States.

Background: Use of normothermic machine perfusion (NMP) may help to expand the liver transplantation (LT) donor pool by potentially increasing the utilization of donation after circulatory death (DCD) organs. The aim of this study was to assess the impact of NMP on LT from DCD organs. Methods: Data among DCD adult LT recipients in the United Network for Organ Sharing between January 2016 and December 2022 were analyzed. Outcomes were compared between 2 groups: NMP versus non-MP using propensity score matching. Results: During the study period, 4217 DCD LT recipients (NMP: 257 and non-MP: 3960) were identified. compared with non-MP, DCD LT recipients in NMP group were older (median recipient age: 61 versus 59 y, P = 0.013), had lower model for the end-stage liver disease score, longer wait time (126 versus 107 d, P = 0.028), and received organs from older donors (median age: 42 versus 38 y, P < 0.01) with longer preservation time (9.9 versus 5.3 h, P < 0.001). Two-year overall survival (NMP 94.4% versus non-MP 89.7%, P = 0.040) and 2-y graft survival (NMP 91.3% versus non-MP 84.6%, P = 0.017) were better in the NMP group. After propensity score matching, 2-y overall survival (NMP 94.2% versus non-MP 88.0%, P = 0.023) and graft survival (NMP 91.3% versus non-MP 81.6%, P = 0.004) were better in the NMP group. On multivariable cox regression analysis, NMP was an independent factor of protection against mortality (hazard ratio, 0.43; 95% confidence interval: 0.20-0.91; P = 0.029) and against graft failure (hazard ratio, 0.26; 95% confidence interval: 0.11-0.61; P = 0.002). Conclusions: Use of NMP for LT from DCD donors was associated with improved posttransplant patient and graft survival.