Non-alcoholic fatty liver disease: Immunological mechanisms and current treatments

Figure 1 Overview of the current understanding of non-alcoholic fatty liver disease progression. Non-alcoholic fatty liver disease (NAFLD) encompasses a range of liver damage, from simple accumulation of fat in liver cells, named steatosis, to more severe forms of the diseases such as steatohepatitis, involving inflammation which can lead to fibrosis and cirrhosis. In the “multiple-hit” theory of progression, the first cause or “first-hit” in NAFLD is insulin resistance, obesity, type 2 diabetes, and metabolic syndrome. As the first hit occurs, free fatty acids are stored in the liver as triglycerides, resulting in simple steatosis. Disease progresses when multiple factors, or “multi-hits”, such as oxidative stress, inflammatory mediators, apoptosis, and mitochondrial dysfunction cause liver damage (created with BioRender.com).