From NAFLD to MAFLD:a“redefining”moment for fatty liver disease

The term non-alcoholic fatty liver disease(NAFLD)was coined in 1980 to characterize a disease similar to alcoholic fatty liver disease that developed in patients without a history of excessive alcohol intake.[1]Morphologically,NAFLD is characterized by excess fatty infiltration of the liver in the absence of known causes of liver disease(eg,alcohol,autoimmune liver disease,viral hepatitis,etc).The clinical manifestations of NAFLD(both hepatic and extrahepatic)depend on the outcome of complex interactions between its primary drivers including poor lifestyle habits and diet,a dysfunctional microbiota,genetic predisposition,and environmental cues that result in metabolic dysfunction and liver disease.However,bringing all patients with their markedly different clinical courses under the NAFLD umbrella belies its complexity and implies a homogeneous disease state that then negatively impacts clinical management and a deeper understanding of pathogenesis.With advances in current knowledge on the spectrum of fatty liver diseases,it is apparent that the fourdecade-old outdated term NAFLD can no longer serve to usefully describe a highly heterogeneous disease.The disease as we understand it today not only impacts patients who consume alcohol and those who do not,but also potentially impacts all patients with any form of liver disease,by acting as a disease modifier.[2]