Significance of Portal Tract Histological Changes in Metabolic Dysfunction-Associated Steatohepatitis

Background: Metabolic dysfunction associated steatohepatitis (MASH) is a leading cause of advanced liver fibrosis globally. Current histological scoring (NAS-CRN) excludes portal-based features, despite emerging evidence suggesting their relevance. Aim: To study the prevalence of portal tract changes and their correlation with fibrosis in liver biopsies from patients with MASH.

Methods: In this retrospective and prospective cross-sectional study, 505 liver biopsies were analysed. Portal inflammation, interface hepatitis, ductular reaction, bile duct damage, and plasma cells were semi-quantitatively assessed. Fibrosis was quantified using whole slide digital images of Sirius red-stained slides, and hepatic progenitor cells (HPC) were measured by CK7 immunohistochemistry.

Results: Mean age was 45.1±12.5 years, with 65% males. Advanced fibrosis (F3–F4) was present in 69.1%. Portal inflammation was observed in 69.3% (predominantly mild). Moderate–severe portal inflammation, plasma cells, interface activity, ductular reaction, duct damage, and HPC were significantly associated with advanced fibrosis (all p≤0.005). Portal inflammation significantly correlated with ductular reaction, interface activity, plasma cell infiltration, bile duct damage, progenitor cells, and fibrosis fraction (all p≤0.005).

Conclusion: Portal inflammation and related features are strongly associated with advanced fibrosis in MASH, thereby suggesting multifactorial role in disease progression and supporting their inclusion in histological scoring systems and routine reporting.

Keywords: Metabolic dysfunction-associated steatohepatitis, histological scoring, portal inflammation, fibrosis, portal features, quantification.