Biochemical biomarkers of NAFLD/NASH

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the Western world and the global epidemics of obesity and type 2 diabetes have led to a dramatic increase of its prevalence and incidence. Among NAFLD patients, those with nonalcoholic steatohepatitis (NASH) have a double risk of fibrosis progression, that is the main driver toward the evolution in cirrhosis and its complications, including hepatocellular carcinoma and hepatic decompensation. Furthermore, patients with NAFLD are also at risk for cardiovascular diseases and extrahepatic malignancies, that represent the first and the second cause of death, respectively. The availability of non-invasive scores to identify patients with NASH, avoiding to perform liver biopsy, still represents a relevant unmet medical need. Ideally, non-invasive biomarkers should be able to distinguish NASH patients among NALFD population, to assess the severity of liver fibrosis, to identify patients at risk of hepatic and extrahepatic complications and finally to predict the response to treatment. To date, liver biopsy remains the gold standard for the diagnosis and the stratification of the prognosis in NASH due to the lack of adequate non-invasive biomarkers in clinical practice. Several scores have been developed for the non-invasive assessment of fibrosis with promising results, although they are often limited by the high rate of false positive results and uncertainty areas. Further studies are needed to improve the diagnostic accuracy of non-invasive biomarkers or to develop new panels with the aim of predicting outcomes and response to treatments.