Decreased Incidence of Acute Cellular Rejection in Low-Muscle-Mass Recipients After Living-donor Liver Transplantation

Background: Sarcopenia has recently been studied as a potential risk factor for mortality and complications after liver transplantation. We investigated the impact of low muscle mass on postoperative outcomes after living-donor liver transplantation. Methods: Our study population consisted of 100 adult recipients who underwent living-donor liver transplantation in our department between 2005 and 2017. Recipients were divided into a low-muscle-mass group (L group) and a normal-muscle-mass group (N group) based on skeletal muscle index (SMI) values, and postoperative outcomes were compared between the groups. Regarding factors that were significantly different between the groups, multivariate analyses were performed to identify predictive factors. Results: Based on the SMI definition, 47 and 53 of the recipients were categorized as having low muscle mass (L group) and normal muscle mass (N group), respectively. Comparison between the groups revealed a significantly reduced incidence of rejection (10.6% in L group vs 30.2% in N group, P =.017) and increased incidences of bacterial infection (61.7% in L group vs 37.7% in N group, P =.017) in the L group compared with the N group. The survival rate did not differ significantly between the groups. Multivariate analyses indicated that muscle mass was a significant predictive factor for both rejection and bacterial infection. Conclusion: It is important to recognize that muscle mass has an impact not only on bacterial infection but also on rejection in recipients with low muscle mass in the postoperative course of living-donor liver transplantation.