RESUMO
Nonalcoholic fatty liver disease (NAFLD) is currently one of most common forms of chronic liver disease globally. NAFLD represents a wide spectrum of liver involvement from nonprogressive isolated steatosis to nonalcoholic steatohepatitis (NASH), characterized by liver necroinflammation and fibrosis and currently one of the top causes of end-stage liver disease and hepatocellular carcinoma. At present, there is a lack of effective treatments, and a central barrier to the development of therapies is the requirement for an invasive liver biopsy for diagnosis of NASH. Discovery of reliable, noninvasive biomarkers are urgently needed. In this study, we tested whether circulating extracellular vesicles (EVs), cell-derived small membrane-surrounded structures with a rich cargo of bioactive molecules, may serve as reliable noninvasive "liquid biopsies" for NASH diagnosis and assessment of disease severity. Total circulating EVs and hepatocyte-derived EVs were isolated by differential centrifugation and size-exclusion chromatography from serum samples of healthy individuals, patients with precirrhotic NASH, and patients with cirrhotic NASH. EVs were further characterized by flow cytometry, electron microscopy, western blotting, and dynamic light scattering assays before performing a proteomics analysis. Our findings suggest that levels of total and hepatocyte-derived EVs correlate with NASH clinical characteristics and disease severity. Additionally, using proteomics data, we developed understandable, powerful, and unique EV-based proteomic signatures for potential diagnosis of advanced NASH. Conclusion: Our study shows that the quantity and protein constituents of circulating EVs provide strong evidence for EV protein-based liquid biopsies for NAFLD/NASH diagnosis.
RESUMO
Background: Hepatitis C virus (HCV) exhibits great genetic diversity and is classified into 7 genotypes (GTs), with varied geographic prevalence. Until the recent development of pangenotypic direct-acting antiviral regimens, the determination of HCV GT was necessary to inform optimal treatment. Methods: Plasma samples with unresolved GT using standard commercial genotyping methods were subjected to HCV full-genome sequencing, and phylogenetic analysis was performed to assign GT. Results: Four patients, previously classified as GT5 by LiPA or Abbott RealTime polymerase chain reaction assays, were identified as infected with a novel HCV GT. This novel HCV GT, GT8, is genetically distinct from previously identified HCV GT1-7 with >30% nucleotide sequence divergence to the established HCV subtypes. All 4 patients were originally from Punjab, India, but now reside in Canada and are epidemiologically unlinked. Despite presence of baseline resistance-associated substitutions within the GT8 virus of all 4 patients (NS3: V36L, Q80K/R; NS5A: Q30S, Y93S), all patients achieved a sustained virologic response; 2 treated with sofosbuvir/velpatasvir/voxilaprevir for 8 weeks, 1 with sofosbuvir/ledipasvir plus ribavirin for 24 weeks and 1 with sofosbuvir plus daclatasvir for 12 weeks. Conclusions: The discovery of a novel HCV GT8 confirms the circulation of this newly identified lineage in the human population.
