Cross-sectional analysis of immunosuppressive regimens focused on everolimus after liver transplantation in a Korean high-volume transplantation center.

Background: The mammalian target of the rapamycin inhibitor has dual inhibitory effects on cell growth and angiogenesis. This study aimed to analyze the usage of everolimus on actual immunosuppression (IS) regimens through a cross-sectional study in a high-volume liver transplantation (LT) center. Methods: Our institutional LT database was searched for adult patients who underwent primary LT surgery between January 2010 and December 2016. We identified 2,093 LT recipients with observation periods of 1 to 8 years. Results: We divided the 2,093 recipients into three groups according to the posttransplant follow-up period as follows: group A (12-36 months; n=680), group B (37-60 months; n=560), and group C (>60 months; n=853). The individual IS agents were tacrolimus in 1,807 patients (86.3%), cyclosporine in 169 patients (8.1%), mycophenolate mofetil (MMF) in 1,310 patients (62.6%), and everolimus in 115 patients (5.5%). The most common IS regimens were tacrolimus-MMF combination and tacrolimus monotherapy, regardless of the posttransplant period. Patients with pretransplant malignancies were administered everolimus more frequently than those without pretransplant malignancies (P<0.001). In 102 patients with hepatocellular carcinoma recurrence or de novo malignancies, IS regimens included everolimus-tacrolimus in 41 patients (40.2%), tacrolimus-MMF in 27 patients (26.4%), tacrolimus in 20 patients (19.6%), MMF in 10 patients (9.8%), cyclosporine in three patients (2.9%), and cyclosporine-MMF in one patient (1.0%). Conclusions: Administration of everolimus after LT has been gradually increasing with the expansion of indications in our institutional practice. Currently, the role of everolimus is minimal and not comparable to that of tacrolimus, but it has a unique position in the field of IS after LT.