Liver biopsy is currently the only reliable method to establish nonalcoholic fatty liver disease (NAFLD) severity. However, this technique is invasive and occasionally associated with severe complications. Thus, non-invasive diagnostic markers for NAFLD are needed. Former studies have postulated 18 different serum microRNA biomarkers with altered levels in NAFLD patients. In the present study, we have re-examined the predictive value of these serum microRNAs and found that 9 of them (miR-34a, -192, -27b, -122, -22, -21, -197, -30c and -16) associated to NAFLD severity in our independent cohort. Moreover, miR-192, -27b, -22, -197 and -30c appeared specific for NAFLD, when compared with patients with drug-induced liver injury. Preliminary serum RNAseq analysis allowed identifying novel potential miRNA biomarkers for nonalcoholic steatohepatitis (NASH). The classification performance of validated miRNAs (and their ratios) for NASH was better than that reached by AST, whereas for advanced fibrosis prediction miRNAs did not perform better than the FIB-4 algorithm. Cross-validated models combining both clinical and miRNA variables showed enhanced predictivity. In conclusion, the circulating microRNAs validated demonstrate a better diagnostic potential than conventional serum markers to identify NASH patients and could complement and improve current fibrosis prediction algorithms. The research in this field is still open.

Summary 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.

No abstract

Original Clinical Science-Liver Background. N-acetylcysteine infusions have been widely used to reduce ischemia/reperfusion damage to the liver; however, convincing evidence of their benefits is lacking. Objective. To perform the largest randomized controlled trial to compare the impact of N-acetylcysteine infusion during liver procurement on liver transplant outcomes. Methods. Single center, randomized trial with patients recruited from La Fe University Hospital, Spain, from February 2012 to January 2016. A total of 214 grafts were transplanted and randomized to the N-acetylcysteine group (n = 113) or to the standard protocol without N-acetylcysteine (n = 101). The primary endpoint was allograft dysfunction (Olthoff criteria). Secondary outcomes included metabolomic biomarkers of oxidative stress levels, interactions between cold ischemia time and alanine aminotransferase level and graft and patient survival (ID no. NCT01866644). Results. The incidence of primary dysfunction was 34% (31% in the N-acetylcysteine group and 37.4% in the control group [P = 0.38]). N-acetylcysteine administration reduced the alanine aminotransferase level when cold ischemia time was longer than 6 h (P = 0.0125). Oxidative metabolites (glutathione/oxidized glutathione and ophthalmic acid) were similar in both groups (P > 0.05). Graft and patient survival rates at 12 mo and 3 y were similar between groups (P = 0.54 and P = 0.69, respectively). Conclusions. N-acetylcysteine administration during liver procurement does not improve early allograft dysfunction according to the Olthoff classification. However, when cold ischemia time is longer than 6 h, N-acetylcysteine improves postoperative ALT levels.

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.