Recent advances in biomarkers for noninvasive diagnosis of nonalcoholic steatohepatitis: the role of lipid analysis/profiling

摘要

Abnormalities of lipid metabolism may be involved in hepatic steatosis, which is a prerequisite for development of nonalcoholic steatohepatitis. In fact, most of the published literature has focused on triglyceride accumulation as the key defect in nonalcoholic fatty liver disease (NAFLD). Fat accumulation in the liver may be due to the excessive uptake of free fatty acids, increased liver lipogenesis, the impairment of fat disposal (as there is decreased (3- and omega-oxidation of free fatty acids), and the decreased secretion of VLDL. The composition of lipids that accumulate in the livers of subjects with NAFLD are not well characterized, however, a number of recent studies have investigated the lipid profile in the livers and plasma of patients with nonalcoholic steatohepatitis. Several findings suggest that the altered lipid profiles may be important in the pathogenesis of NAFLD, whereas others emphasize that lipid alterations are an adaptive response to protect the liver against lipotoxicity. Interestingly, plasma lipidomics, together with the emerging mass spectrometry and bioinformatical techniques, seem to be a promising noninvasive diagnostic too! to distinguish fatty liver from nonalcoholic steatohepatitis and to predict the risk of metabolic syndrome. In addition, this analysis of the plasma lipidomic signature could suggest novel potential molecular targets and pathways, thus offering alternative opportunities for therapeutic interventions both on the 'whole body' lipid dysmetabolism and on liver damage. In this article, we will discuss the recent advances for an early noninvasive diagnosis of NAFLD, with particular emphasis on the diagnostic value of the plasma lipidome.