Survival benefit of liver transplantation utilizing marginal donor organ according to ABO blood type.

BACKGROUND The current liver transplantation (LT) allocation policy focuses on the Model for End-Stage Liver Disease (MELD) scores, often overlooking factors like blood type and survival benefits. Understanding blood types' impact on survival benefits is crucial for optimizing the MELD 3.0 classification. METHOD This study used the United Network for Organ Sharing national registry database (2003-2020) to identify LT characteristics per ABO blood type and to determine the optimal MELD 3.0 scores for each blood type, based on survival benefits. RESULTS The study included LT candidates aged 18 years or older listed for LT (total N=150,815; A:56,546, AB:5,841, B:18,500, O:69,928). Among these, 87,409 individuals (58.0%) underwent LT (A:32,156, AB:4,362, B:11,786, O:39,105). Higher transplantation rates were observed in AB and B groups, with lower median MELD 3.0 scores at transplantation (AB:21, B:24 vs. A/O:26, p<0.01) and shorter waiting times (AB:101 days, B:172 days vs. A:211 days, O:201 days, p<0.01). A preference for Donation after Cardiac Death (DCD) was seen in A and O recipients. Survival benefit analysis indicated that B blood type required higher MELD 3.0 scores for transplantation than A and O (Donation after Brain Death transplantation: ≥15 in B vs. ≥11 in A/O; DCD transplantation: ≥21 in B vs. ≥11 in A, ≥15 in O). CONCLUSION The study suggests revising the allocation policy to consider blood type for improved post-LT survival. This calls for personalized LT policies, recommending higher MELD 3.0 thresholds, particularly for individuals with type B blood.