High prevalence of de novo metabolic dysfunction-associated fatty liver disease after liver transplantation and the role of controlled attenuation parameter

Background & Aims Although non-alcoholic fatty liver disease (NAFLD) remains an uncommon indication for liver transplantation (LT) in the Chinese, the prevalence of NAFLD is increasing. We aimed to determine the prevalence of de novo steatosis and metabolic dysfunction-associated fatty liver disease (MAFLD) after LT. Methods Transient elastography assessment for liver stiffness and controlled attenuation parameter (CAP) were performed after LT in 549 patients at median time of 77 months from LT. CAP was compared with implant liver biopsy, and also validated in 42 patients with post-LT liver biopsy. Longitudinal history including diabetes mellitus (DM), dyslipidemia, hypertension, and immunosuppressive regimen were recorded. Results The optimal cut-off level of CAP for diagnosing at least mild (≥ S1) and moderate-to-severe steatosis (≥ S2/3) was 266 and 293 dB/m respectively, with AUROC of 0.740 and 0.954 respectively. Using this newly derived cut-off, 28.9% patients have de novo NAFLD, of which 95.6% fulfilled the criteria for MAFLD. After multivariate analysis, BMI (HR 1.34), DM (HR 2.01), hypertension (HR 2.03), HDL-cholesterol (HR 0.25), LDL-cholesterol (HR 1.5) and cryptogenic cirrhosis (HR 4.85) were associated with the development of S2/3 graft steatosis. de novo NAFLD was associated with higher incidence of new-onset hypertension (p < 0.001), graft dysfunction (defined as ALT > 40 U/L; p = 0.008), but not associated with graft fibrosis (defined as liver stiffness > 12 kPa; p = 0.761). Conclusion Although NAFLD remains an uncommon primary liver disease indication for LT in Chinese patients, post-transplant de novo graft steatosis is common and the majority is classified as MAFLD. Development of graft steatosis is not associated with an increase in graft fibrosis but was associated with worse metabolic control and graft dysfunction. Routine CAP measurement to detect de novo graft steatosis should be considered after LT regardless of the primary indication of LT.