Low-dose aspirin confers protection against acute cellular allograft rejection after primary liver transplantation.

OBJECTIVE To investigate the effect of low-dose aspirin in primary adult liver transplantation LT on acute cellular rejection ACR as well as arterial patency rates. BACKGROUND The use of low-dose aspirin after LT is practiced by many transplant centers to minimize the risk of hepatic artery thrombosis HAT, although solid recommendations do not exist. However, aspirin also possesses potent anti-inflammatory properties and might mitigate inflammatory processes after LT, such as rejection. Therefore, we hypothesized that the use of aspirin after liver transplantation has a protective effect against ACR. METHODS This is an international, multicenter cohort study of primary adult deceased donor LT. The study included 17 high-volume LT centers and covered the 3-year period from 2013 to 2015 to allow a minimum 5-year follow-up. RESULTS In this cohort of 2,365 patients, prophylactic antiplatelet therapy with low-dose aspirin was administered in 1,436 recipients 61%. One-year rejection-free survival rate was 89% in the aspirin group versus 82% in the no-aspirin group HR 0.77, 95% CI 0.63-0.94, p=0.01. One-year primary arterial patency rates were 99% in the aspirin and 96% in the no-aspirin group with a HR of 0.23 95% CI: 0.13-0.40; p<0.001. CONCLUSION Low-dose aspirin was associated with a lower risk of ACR and HAT after LT, especially in the first vulnerable year after transplantation. Therefore, low-dose aspirin use after primary LT should be evaluated to protect the liver graft from ACR and to maintain arterial patency