Non-invasive diagnosis and monitoring of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent form of chronic liver disease that poses challenges in diagnosis and risk stratification. Non-alcoholic steatohepatitis (NASH), the more progressive form of NAFLD, is particularly challenging to diagnose in the absence of histology. Liver biopsy is infrequently performed due to its invasive nature, potential for sampling error, and lack of inter-rater reliability. Non-invasive tests that can accurately identify patients with at-risk NASH (ie, individuals with biopsy-proven NASH with NAFLD activity score [NAS] & GE;4 and fibrosis stage & GE;2) are key tools to identify candidates for pharmacologic therapy in registrational trials for the treatment of NASH-related fibrosis. With emerging pharmacotherapy, non-invasive tests are required to track treatment response. Lastly, there is an unmet need for non-invasive tests to assess risk for clinical outcomes including progression to cirrhosis, hepatic decompensation, liver-related mortality, and overall mortality. In this Review we examine advances in non-invasive tests to diagnose and monitor NAFLD and NASH.

Automated summary

Non-alcoholic fatty liver disease (NAFLD) is a common and challenging form of chronic liver disease. Non-alcoholic steatohepatitis (NASH), the more severe form of NAFLD, is difficult to diagnose without a liver biopsy. Non-invasive tests are needed to accurately identify patients with at-risk NASH and monitor treatment response. There is also a need for non-invasive tests to assess the risk of clinical outcomes. This review discusses the advancements in non-invasive tests for diagnosing and monitoring NAFLD and NASH.