The surveillance of progression and assessment of treatment endpoint for nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) is the aggressive form of nonalcoholic fatty liver disease (NAFLD), characterized as steatosis-associated inflammation and liver injury. Without effective treatment or management, NASH would develop life-threatening outcomes. In this situation, evaluation and identification of those at-risk for adverse outcomes are important. The key issues in screening NASH patients are the assessment of advanced fibrosis, differentiation of NASH from simple steatosis, and their dynamic changes during follow-up. Currently, the staging for NASH and evaluation of effectiveness for drugs still rely on pathological diagnosis, while liver biopsy brings sample error issues and subjectivity. To address this problem, optimizing the pathological assessment and developing noninvasive surrogate methods for accessible, accurate, and safe evaluation is of significance. Although noninvasive methods including elastography, serum soluble biomarkers and combined models have been widely studied in the last decade, the application of noninvasive diagnostic measurements in clinical practice is still insufficient. Much work remains to be done in establishing cost-effective strategies both for screening for at-risk NASH and identify the changes of disease severity. In this review, we summarized the current state of the noninvasive methods for detecting steatosis, steatohepatitis and fibrosis of NASH, introduced the noninvasive assessment for screening at-risk patients, and focused on the characteristics should be monitored in the follow-up.