Non-invasive identification of steatohepatitis in patients with MASLD using a sterol and lipidomic signature.

The accumulation of cholesterol and other lipids leading to hepatic lipotoxicity drives the progression of metabolic dysfunction-associated steatotic liver (MASL) to metabolic dysfunction-associated steatohepatitis (MASH), the advanced progressive stage of metabolic dysfunction-associated steatotic liver disease (MASLD). For MASH diagnosis, liver biopsy remains the reference standard, despite its invasiveness and limitations. Thus, this study aimed to find blood-derived lipid markers for MASH. We investigated serum samples from 86 patients with histologically characterized MASLD, spanning the disease spectrum (i.e. 62 patients with MASL (Fibrosis grade 0-4) and 24 patients with MASH (Fibrosis grade 2-4) with a balanced distribution of hepatocellular carcinoma) and analyzed sterol composition and lipidome. To identify the presence of MASH, logistic regression was performed on each candidate either in a single or combination with various clinical parameters. Serum levels of desmosterol and phosphatidylcholine are increased in patients with MASH compared to those with MASL. After exclusion of patients using lipid lowering drugs, an increase was also found in serum levels of cholesterol, cholesterol ester, lysophosphatidylcholine, lysophosphatidylethanolamine, phosphatidylethanolamine, and several individual lipid species. The ROC curve of each lipid candidate show the potential use of desmosterol, phosphatidylcholine, and a panel of lipid species in combination with alanine aminotransferase as potential diagnostic markers, characterized by a respective AUROC of 0.79 (95% CI 0.66-0.92), 0.80 (95% CI 0.64-0.97), and 0.91 (95% CI 0.82-1.00). Serum sterol and lipidome markers are characterized by strong AUROC results to distinguish with high accuracy MASH from MASL, potentially paving the way for future MASH biomarker development.