Decrease in the Risk of Post-Transplant Hepatocellular Carcinoma Recurrence After the Conversion to Prestorage Leukoreduction for Transfused Red Blood Cells.

BACKGROUND: Prestorage leukoreduction has the advantage over poststorage leukoreduction in reducing leukocyte-derived molecules in RBC unit, which induce immunomodulation. Our institution newly introduced prestorage leukoreduction, instead of conventional poststorage leukoreduction, for liver transplant recipients since March 2012. In this study, we aimed to evaluate the risk of post-transplant hepatocellular carcinoma(HCC) recurrence after the conversion of poststorage leukoreduction into prestorage leukoreduction for transfused allogeneic red blood cell(RBC) units. METHODS: Among 220 recipients of grafts, from living donors, for HCC:83/113 who received only poststorage-leukoreduced RBCs were matched with 83/107 who received only prestorage-leukoreduced RBCs using 1:1 propensity score matching based on factors like tumor biology. The primary outcome was overall HCC recurrence. Survival analysis was performed with death as a competing risk event. RESULTS: In the matched cohort, recurrence probability at 1/2/5 years post-transplant was 9.6/15.6/18.1% in prestorage group and 15.6/21.6/33.7% in poststorage group (hazard ratio(HR)=0.52 [0.28-0.97], P=0.040). Multivariable analysis confirmed a significance of prestorage leukoreduction (HR=0.29 [0.15-0.59], P<0.001). Overall death risk was also lower with prestorage leukoreduction (HR=0.51 [0.26-0.99], P=0.049). In subgroup analysis for the unmatched cohort, recurrence risk was significantly lower in prestorage group within the patients who underwent surgery 2 years (HR=0.24 [0.10-0.61], P=0.002), 1 year (HR=0.16 [0.03-0.92], P=0.040), and 6 months (HR=0.13 [0.02-0.85], P=0.034), respectively, before and after the conversion to prestorage leukoreduction. CONCLUSIONS: Our findings suggest a potential benefit of prestorage leukoreduction in reducing the risk of HCC recurrence in liver transplant recipients who received allogeneic RBCs during the perioperative period.