Digital Pathology Quantification of the Continuum of Cirrhosis Severity in Human Liver Biopsies.

BACKGROUND AND AIMS: Liver biopsy is the gold standard for assessing fibrosis in cirrhotic livers, yet cirrhosis is spatially heterogeneous and continuously remodels. This study evaluates a novel phenotypic digital pathology platform for continuous fibrosis severity quantification and sensitivity to sampling variability. APPROACH AND RESULTS: Five needle biopsies were collected from 20 HCV-cirrhotic livers during transplantation. Histological staging used the Laennec (4A-4C) and Beijing (progressive, regressive, indeterminate) systems. Collagen proportionate area (CPA) was measured via computerised morphometry. The FibroNest platform analysed high-resolution, single-fibre images to extract 336 parameters, generating a continuous fibrosis severity score (Ph-FCS) and tailored scores for Laennec (Ph-FCS(L)) and Beijing (Ph-FCS(B)) systems. A comparative MASLD cohort (n = 73, NASH-CRN stages) was also included. The range of the Ph-FCS was broader to cover the cirrhosis spectrum (6.44 units) than from F0 to F3 (5.39 units). Ph-FCS was less affected by biopsy variability (16.7% ± 1.3%) compared to CPA (47.3% ± 4.5%). Ph-FCS(L) and Ph-FCS(B) demonstrated moderate concordance with the Laennec and Beijing stages. Their ability to classify patients into Laennec and Beijing stages was limited (0.610 < AUROCS < 0.789). At best, Ph-FCS(L) and Ph-FCS(B) distinguished stages 4A from 4C and P from R with AUROCs of 0.747(95% CI: 0.611-0.879) and 0.798 (95% CI: 0.645-0.929). CONCLUSIONS: Phenotypic digital pathology biomarkers provide robust, continuous measures of fibrosis severity and activity. They enhance traditional staging systems by offering improved resolution and reduced sensitivity to biopsy variability, with potential value in cirrhosis sub-staging and clinical decision-making.