Does prior radiotherapy impact the acute cellular liver graft rejection?

Radiotherapy can be used as a bridge therapy prior to liver transplantation. Radiotherapy generates immune reactions involving T cells, which are the main effectors of acute cellular rejection after transplantation. Here, we investigated the impact of radiotherapy on acute cellular rejection.

We retrospectively reviewed the data of oncological patients who benefited from liver transplantation. Patients who received radiotherapy prior to liver transplantation ("RT cohort", n=17) were compared to a matched cohort ("NoRT_matched cohort", n=17) obtained through propensity score-matching analysis of the total non-irradiated cohort ("NoRT_all" cohort, n=136). The acute cellular rejection was evaluated using the Banff score for rejection (mild:<5, moderate: 5-6, and severe: 7-9) obtained on an early post-transplantation biopsy. Overall and disease-free survival were reported for patients with hepatocellular carcinoma.

Median Banff scores was significantly lower for the RT cohort compared to the NoRT_all cohort (2.5 versus 5, respectively, P=0.043) but this statistical difference was eliminated after comparison with the NoRT_matched cohort (median: 4, P=0.62). The 5-year overall and disease-free survival rates were 62 % and 69 %, respectively, for hepatocellular carcinoma patients of the RT cohort (n=14) and did not differ from the 5-year overall (83 %, P=0.15) and disease-free survival rates (90 %, P=0.05) of those of the NoRT_matched cohort (n=16).

Radiotherapy given prior to liver transplantation did not impact the rate or severity of acute cellular rejection. Furthermore, overall and disease-free survival rates were not impacted by radiotherapy.