Prevalence and Impact of Fatty Liver Disease in Adult Deceased Liver Transplant Donors: Metabolic‐Associated Fatty Liver Disease or Nonalcoholic Fatty Liver Disease?

Donor hepatic steatosis is associated with worse post– liver transplantation (LT) outcomes, especially when >30%.(1) Such donors usually have nonalcoholic fatty liver disease (NAFLD), which is defined as fatty liver (hepatic steatosis >5%) without excessive alcohol consumption (>210 g/week for men, >140 g/week for women) or concomitant liver disease. Recently, international consensus has proposed that the term NAFLD be replaced by metabolicassociated fatty liver disease (MAFLD).(2) New criteria define MAFLD as fatty liver together with the presence of metabolic conditions (ie, type 2 diabetes mellitus, elevated ethnicityspecific body mass index [BMI], or at least 2 of the following: elevated waist circumference, hypertension, dyslipidemia, prediabetes, and/or insulin resistance).(2) We know that metabolic variables such as raised BMI and diabetes mellitus in a donor also contribute to graft marginality.(1,3) We examined whether a biopsyproven diagnosis of NAFLD or MAFLD in a liver donor had an impact on outcomes. We analyzed donor and recipient data from a previously described cohort of 798 patients who underwent deceased donor LT at our center.(1) Of these, 723 had a postimplantation liver biopsy available for steatosis assessment. Hepatic steatosis was present in 30.7% of donors: 24.1% had S1 (5%33%), 5.5% had S2 (34%66%), and 1.1% had S3 (>66%). NAFLD and MAFLD were present in 22.5% and 24.2% of the accepted liver donors, respectively. Among donors with fatty liver disease (either NAFLD or MAFLD), the diagnoses overlapped in 63.3% (131/207) of donors, 44 donors (21.3%) fulfilled MAFLD but not NAFLD, and 32 donors (15.5%) fulfilled NAFLD but not MAFLD definitions (Table 1). Compared with donors without fatty liver disease, NAFLD/MAFLD donors were older (median age 53 versus 47 years; P < 0.001), had higher BMIs (median 27.328.4 versus 24.7 kg/m2; P < 0.001) and higher alanine aminotransferase levels (median 37 versus 30 U/L; P = 0.02), and were more likely to have a cardiovascular cause of death (72.6%74.8% versus 57.9%; P < 0.001). Donors with MAFLD had a higher BMI (median 28.4 versus 27.3 kg/m2; P < 0.01) and were more likely to have a history of excessive alcohol consumption (26.1% versus 0%; P < 0.001) compared with donors with NAFLD, although the latter was unsurprising considering the definition of NAFLD. Otherwise, there were no significant differences in characteristics between NAFLD and MAFLD donors. In particular, the distribution of hepatic steatosis severity (S1S3) was similar between the 2 groups (P = 0.99). The donor Abbreviations: BMI, body mass index; EAD, early allograft dysfunction; HSCRP, highsensitivity Creactive protein; LT, liver transplantation; MAFLD, metabolicassociated fatty liver disease; NA, not available; NAFLD, nonalcoholic fatty liver disease.

[1]  C. Pulitano,et al.  Differential Impact of Extended Criteria Donors After Brain Death or Circulatory Death in Adult Liver Transplantation , 2020, Liver transplantation : official publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society.

[2]  V. Wong,et al.  A new definition for metabolic associated fatty liver disease: an international expert consensus statement. , 2020, Journal of hepatology.

[3]  M. Abecassis,et al.  Validation of a current definition of early allograft dysfunction in liver transplant recipients and analysis of risk factors , 2010, Liver transplantation : official publication of the American Association for the Study of Liver Diseases and the International Liver Transplantation Society.