Purpose: The relationship between tacrolimus intrapatient variability (IPV) and its metabolism-associated singlenucleotide polymorphisms (SNPs) in liver transplantation (LT) remains unclear. Moreover, the influence of donor SNP on recipient IPV is poorly understood. Our objective was to investigate how SNPs affect tacrolimus IPV by analyzing both donor and recipient SNP data in LT. Methods: This retrospective study examined the association between tacrolimus IPV and eight specific SNPs in 50 adult LT recipients and 50 LT donors genotyped for CYP3A5, ABCB1, ABCC2, and POR genes and their SNPs. Recipients were divided into high IPV (≥30) and low IPV (<30) groups based on 3–12 months after LT IPV calculations. Multivariate logistic regression was used to identify risk factors for high IPV. Post-LT long-term outcomes were also compared between the groups. Results: Two SNPs were significantly associated with high IPV in multivariate analysis. Recipient ABCB1 1236C>T genotypes CT and CC (odds ratio [OR], 13.969; 95% confidence interval [CI], 1.738–112.300; P = 0.013), donors’ CYP3A5 6986A>G genotypes GA and GG (OR, 4.390; 95% CI, 1.005–19.178; P = 0.049), and glucose ≥120 mg/dL at 3 months (OR, 6.494; 95% CI, 1.300–32.168; P = 0.024) were associated with high IPV. However, post-LT long-term outcomes were similar between the groups. Conclusion SNPs of donor CYP3A5 and recipient ABCB1 can significantly influence tacrolimus IPV in patients undergoing living donor LT. Identifying these SNPs can help determine high IPV-prone patients, facilitate close monitoring of high IPVsusceptible groups, and improve outcomes.

Background: Challenging clinical circumstances and high demand for liver transplantation have led to a refinement in the recipient selection criteria. This study aims to investigate the hypothesis that surgical outcomes in living donor liver transplantation (LDLT) for hepatocellular carcinoma (HCC) have improved over time with the shift from morphological to biological criteria. Methods: A retrospective analysis was conducted on 942 adult HCC patients underwent LDLT at Seoul National University Hospital between 2000 and 2022. Study populations were divided into Group A (2000.01.01–2011.06.30, n=314) and Group B (2011.07.01–2022.06.30, n=628). Baseline characteristics, perioperative factors, and survival outcomes were compared. Results: Group B demonstrated higher recurrence-free survival (RFS) compared to Group A (p=0.03). Additionally, Group B exhibited superior overall survival rates at the 1-, 3-, and 5-year intervals (95.9%, 87.9%, 84.6%, p<0.01). Moreover, Group B had a significantly lower recurrence rate (p=0.02) and mortality rate (p<0.01). The median time to recurrence was 9.1 months (interquartile range [IQR] 3.9–21.8) for Group A and 11.4 months (IQR 6.6–18.5) for Group B (p=0.92). Furthermore, Group A’s median tumor-bearing survival was 12.3 months (IQR 5.2–26.1), which was significantly shorter than Group B’s 20.0 months (IQR 5.4–25.7) (p<0.01). Conclusion The use of biological tumor markers in patient selection criteria has significantly improved the effectiveness of HCC treatment in LDLT and should be encouraged for pervasive use.