Errors in modeling misrepresent the utility of the enhanced liver fibrosis test in the management of non-alcoholic fatty liver disease

Derivation and validation of Transform equations to convert historical Enhanced liver fibrosis (ELF) scores to modern equivalents

BACKGROUND AND AIMS

The Siemens Healthineers ELF™ Test was designed in 2004 with 2 algorithms to allow choice in histological alignment. Consequently, historical and modern algorithms are not fully harmonized, complicating comparisons involving early datasets. We derived transform equations to equate all ELF score versions, allowing historical data to be used in systematic reviews and meta-analyses.

METHODS

Historical ELF equations were graphed pairwise versus their modern equivalent to assess correlation and derive four transforms. Transforms were validated using multiple datasets and evaluated for median absolute bias, number of samples reflecting clinically significant bias, number of discordant samples, bias at established cutoffs, and regression slope and y-intercept.

RESULTS

Three transforms were validated equating Scheuer-aligned and/or age-included historical ELF equations (Immuno 1) to later equations aligned to Ishak and omitting age. A fourth transform corrected ADVIA Centaur® / Atellica® IM ELF scores miscalculated using the Scheuer Immuno 1 equation. Transformed data were well within allowable ELF bias limits.

CONCLUSIONS

All transforms enabled accurate comparison of ELF scores generated by all historical algorithms to the current ADVIA Centaur / Atellica IM Analyzer ELF score. The transforms presented in this report should be used in systematic reviews and meta-analyses to facilitate comparisons to historical data.

Meta-analysis: Enhanced liver fibrosis test to identify hepatic fibrosis in chronic liver diseases

BACKGROUND & AIMS

Patients with liver disease can be stratified for risk of liver-related ill health by degree of hepatic fibrosis. The Enhanced liver fibrosis (ELF) test was developed to quantify hepatic fibrosis non-invasively and is widely used. The objective of this review was to identify and synthesise the evidence on the diagnostic accuracy of the ELF test for staging of hepatic fibrosis.

APPROACH & RESULTS

Searches of PubMed and EMBASE were conducted between October 2020 and November 2021 to identify studies reporting the diagnostic accuracy of the ELF test compared to histology in liver disease patients. QUADAS-2 was used to assess risk of bias in each study. Meta-analysis using the multiple thresholds model described by Steinhauser S, Schumacher M, Rücker G. Modelling multiple thresholds in meta-analysis of diagnostic test accuracy studies. BMC Med. Res. Methodol. 2016;16. 10.1186/s12874-016-0196-1 allowed synthesis of 2 × 2 data at different cut-offs. Sixty-three studies were included in this review. These studies included 19,285 patients with or at risk of liver disease from viral hepatitis, Non-Alcoholic Fatty Liver Disease, Alcohol-related Liver Disease and other mixed chronic liver diseases. The prevalence of significant fibrosis, advanced fibrosis and cirrhosis was 47.5%, 39.2% and 4.4%, respectively. Cut-offs with maximal Youden index were generated with AUROC = 0.811 (95% CI: 0.736-0.870), 0.812 (95% CI: 0.758-0.856) and 0.810 (95% CI: 0.694-0.888) to detect significant fibrosis, advanced fibrosis or cirrhosis, respectively. Diagnostic accuracy of the ELF test varied between different liver diseases and cut-offs to detect each stage with 95% sensitivity or specificity were also generated.

CONCLUSIONS

Meta-analysis revealed considerable variability in the ability of ELF to stage fibrosis across disease aetiologies. Research has mostly focused on viral hepatitis and NAFLD. There is currently a lack of data on the value of the ELF test in Alcohol-related liver disease and patients in primary care settings.

Y-box binding protein 1 regulates liver lipid metabolism by regulating the Wnt/β-catenin signaling pathway

Background

We mainly investigated how y-box binding protein 1 (YB-1) regulates liver lipid metabolism through the Wnt/β-catenin signaling pathway using multiple models.

Methods

The LO2 cells were treated with palmitic acid (PA) to create an NAFLD model in vitro. Immunohistochemistry and Western blotting assays were used to detect the expression of YB-1, β-catenin, SREBP-1c, LXRa, FXR1 and PPARα protein, and RNAs of them was detected by qRT-PCR. Oil Red O assay was applied to observe lipid droplets in LO2 cells and liver tissues. H&E staining was performed to observe the degree of liver inflammation. Proteomics in LO2 cells were conducted by Tandem mass tag proteomics assay. Co-immunoprecipitation and Western blotting assays were used to verify YB-1 complexed pGSK3β. ELISA and Western blotting assays were used to detect the concentrations of TNFα and IL-6 in LO2 cells and liver tissues, respectively.

Results

We found that YB-1 and β-catenin were highly expressed in the LO2 cell NAFLD model, and that the expression of TNFα and IL-6 also increased. Lipid synthases (SREBP-1c and LXRa) expression were decreased, while β-oxidation-related factors (FXR1 and PPARα) expression were increased. The expression of SREBP-1c and LXRa were increased while FXR1 and PPARα were decreased, though such responses were rescued through inhibiting β-catenin expression. Finally, tandem mass tag proteomics, co-immunoprecipitation, and Western blotting demonstrated that YB-1 could form a protein complex with phosphorylated glycogen synthase kinase 3 beta (pGSK3β) to regulate Wnt/β-catenin. In mouse NAFLD livers, immunohistochemistry and Western blotting validated the finding of YB-1 gene downregulation leading to the inhibition of Wnt/β-catenin pathway activation, ultimately inhibiting lipid synthesis and reducing the inflammatory response. Similar to the in vitro investigation, β-catenin overexpression reversed such YB-1 downregulation-induced downstream effects. Upregulation of the YB-1 gene promoted the activation of the Wnt/β-catenin pathway, thus increasing lipid synthesis and the inflammatory response. However, downregulation of β-catenin reversed this phenomenon caused by upregulating YB-1.

Conclusions

In summary, these results demonstrate that YB-1 regulates liver lipid metabolism by regulating the Wnt/β-catenin signaling pathway.