[Non-alcoholic steatohepatitis (NASH) : a model of metabolic inflammation («metaflammation»)]

Diseases related to fatty liver, independently of alcohol consumption («non-alcoholic fatty liver disease» or NAFLD), are increasing because of the epidemics of obesity and type 2 diabetes. These disorders reflect a continuum that comprises isolated steatosis, steatohepatitis (NASH) and fibrosis, with, at the end, an increased risk of cirrhosis and hepatocarcinoma. It has been recently proposed to replace the term NAFLD by MAFLD, i.e. «Metabolic (dysfunction) Associated Fatty Liver Disease», which better reflects the pathogenesis of the disease. Inflammation plays a crucial role in the aggravation of the disorder and profoundly influences the prognostic evolution. This article illustrates the natural history of this underestimated metabolic disorder, recall the diagnostic criteria used in clinical practice, emphasizes the deleterious role of inflammation and discusses some therapeutic perspectives.