Exploring pre-surgery donor-specific antibodies in the context of organ shortage in liver transplant

Background: There is a growing disparity between the number of liver transplant (LT) candidates and availability of suitable liver allografts. Antibody-mediated rejection (AMR), secondary to positive donor-specific antibodies (DSA), remains a concern in liver transplantation. This study aimed to correlate expression of DSA on pre-transplant screening and outcomes of LT, specifically development of AMR in liver allografts and liver function profile in the post-operative period.

Methods: Data of consecutive patients undergoing orthotopic LT (OLT) at the South Australian Liver Transplant Unit was analysed. All patients underwent DSA testing pre-transplant.

Results: Within a cohort of 96 patients, over a post-OLT median follow-up of 849 days, only 2 patients (2%) developed AMR. While both patients had a positive DSA test preoperatively, overall DSA positivity was noted in 31% patients, with a specificity for prediction of AMR of 0.708. No significant association was noted between AMR (p = 0.092), T cell–mediated rejection/TCMR (p = 0.797) or late hepatic artery thrombosis/LHAT (p = 0.521). There was no significant interaction effect between DSA positivity and serum bilirubin or transaminases over a period of 100 days.

Conclusion: AMR following LT is uncommon. A positive DSA pre-transplant does not imply a definite risk of AMR. Also, there does not exist a significant interaction in time between DSA expression and serum bilirubin or transaminase levels. Until there emerges evidence to the contrary, it appears reasonable to consider DSA-positive donors within the broad context of marginal donors in the context of a worldwide shortage of LT donor allografts.