Evaluation of hepatic sonic hedgehog protein expression in the diagnosis of metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is an advanced form of metabolic dysfunction-associated fatty liver disease, with diagnosis relying on liver biopsy. The identification of ballooned hepatocytes in routine hematoxylin-eosin staining is subjective and exhibits significant interobserver variability. Sonic hedgehog homolog (SHH) is specifically expressed in ballooned hepatocytes and holds potential as a positive immunohistochemical marker. This review evaluates the diagnostic value of SHH expression in MASH based on available evidence. Studies demonstrate that SHH staining improves the consistency of interpretation of ballooned hepatocytes and correlates with disease severity, serum biomarkers, and fibrosis staging. However, most evidence comes from single-center retrospective studies with a limited number of observers. The independent predictive value of SHH requires validation through prospective multicenter cohort studies. In summary, SHH immunohistochemistry is a promising adjunctive diagnostic tool for MASH, though its clinical application remains in the preliminary stages.