Digital Pathology Enables Automated and Quantitative Assessment of Inflammatory Activity in Patients with Chronic Liver Disease.

Traditional histological evaluation for grading liver disease severity is based on subjective and semi-quantitative scores. We examined the relationship between digital pathology analysis and corresponding scoring systems for the assessment of hepatic necroinflammatory activity. A prospective, multicenter study including 156 patients with chronic liver disease (74% nonalcoholic fatty liver disease-NAFLD, 26% chronic hepatitis-CH etiologies) was performed. Inflammation was graded according to the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network system and METAVIR score. Whole-slide digital image analysis based on quantitative (I-score: inflammation ratio) and morphometric (C-score: proportionate area of staining intensities clusters) measurements were independently performed. Our data show that I-scores and C-scores increase with inflammation grades (p < 0.001). High correlation was seen for CH (ρ = 0.85-0.88), but only moderate for NAFLD (ρ = 0.5-0.53). I-score (p = 0.008) and C-score (p = 0.002) were higher for CH than NAFLD. Our MATLAB algorithm performed better than QuPath software for the diagnosis of low-moderate inflammation (p < 0.05). C-score AUC for classifying NASH was 0.75 (95%CI, 0.65-0.84) and for moderate/severe CH was 0.99 (95%CI, 0.97-1.00). Digital pathology measurements increased with fibrosis stages (p < 0.001). In conclusion, quantitative and morphometric metrics of inflammatory burden obtained by digital pathology correlate well with pathologists' scores, showing a higher accuracy for the evaluation of CH than NAFLD.

Digital pathology: accurate technique for quantitative assessment of histological features in metabolic-associated fatty liver disease.

BACKGROUND: Histological evaluation of metabolic-associated fatty liver disease (MAFLD) biopsies is subjective, descriptive and with interobserver variability. AIMS: To examine the relationship between different histological features (fibrosis, steatosis, inflammation and iron) measured with automated whole-slide quantitative digital pathology and corresponding semiquantitative scoring systems, and the distribution of digital pathology measurements across Fatty Liver Inhibition of Progression (FLIP) algorithm and Steatosis, Activity and Fibrosis (SAF) scoring system METHODS: We prospectively included 136 consecutive patients who underwent liver biopsy for MAFLD at three Spanish centres (January 2017-January 2020). Biopsies were scored by two blinded pathologists according to the Non-alcoholic Steatohepatitis (NASH) Clinical Research Network system for fibrosis staging, the FLIP/SAF classification for steatosis and inflammation grading and Deugnier score for iron grading. Proportionate areas of collagen, fat, inflammatory cells and iron deposits were measured with computer-assisted digital image analysis. A test-retest experiment was performed for precision repeatability evaluation. RESULTS: Digital pathology showed strong correlation with fibrosis (r = 0.79; P < 0.001), steatosis (r = 0.85; P < 0.001) and iron (r = 0.70; P < 0.001). Performance was lower when assessing the degree of inflammation (r = 0.35; P < 0.001). NASH cases had a higher proportion of collagen and fat compared to non-NASH cases (P < 0.005), whereas inflammation and iron quantification did not show significant differences between categories. Repeatability evaluation showed that all the coefficients of variation were ≤1.1% and all intraclass correlation coefficient values were ≥0.99, except those of collagen. CONCLUSION: Digital pathology allows an automated, precise, objective and quantitative assessment of MAFLD histological features. Digital analysis measurements show good concordance with pathologists´ scores.

Prospective validation of a noninvasive index for predicting liver fibrosis in hepatitis C virus-infected liver transplant recipients.

We previously developed a mathematical model, the Hospital Universitario La Fe (HULF) index, as an alternative to protocol liver biopsy (PLB) to estimate significant fibrosis (SF) in patients who underwent liver transplantation (LT) for liver damage caused by chronic HCV infection. In the present study, we sought to validate this noninvasive index. The commonly derived clinical and laboratory data for calculating the HULF index were prospectively collected over 2.7 years from patients undergoing LT and PLB. The sensitivity, specificity, positive and negative predictive values, and diagnostic capacity were evaluated with receiver operating characteristic curve analysis. Biopsy was performed 93 times in 86 LT patients. The prevalence of SF (F3-F4 on the Knodell scoring system) was 32%. The intraobserver and interobserver concordance was high (kappa = 0.94 and kappa = 0.75, respectively) in identifying SF in PLB. For low scores, the HULF index discarded an SF diagnosis with a sensitivity of 90% and a negative predictive value of 89%. The area under the receiver operating characteristic curve was 0.68. The precision of the HULF index did not improve with the incorporation of donor age and body mass index into the multivariate analysis. Applying the index would have prevented 24% of the biopsy procedures performed. In conclusion, the HULF index was prospectively validated with data commonly obtained in standard clinical practice. Because the index distinguishes a subgroup of HCV LT patients with a low probability of having SF, PLB would be avoided in those patients.