Background and aims: Non-alcoholic steatohepatitis (NASH), the inflammatory subtype of non-alcoholic fatty liver disease (NAFLD) associated with obesity and type2 diabetes mellitus (T2DM) can lead to advanced liver disease.There are limited data evaluating T cell subsets in multiple tissue compartments or following weight loss in NAFLD.We hypothesised that circulating and tissue T cells changed in advanced versus mild NASH.Method: Prospective samples were collected under ethicallyapproved protocols; peripheral blood from 37 NAFLD patients and 7 controls, with primary comparisons between advanced (elastography >9.7kPa or ≥F3) and mild (elastography <8.2kPa or ≤F2) NAFLD.A subset undergoing bariatric surgery (n = 21) underwent additional simultaneous sampling of liver, visceral (VAT) and subcutaneous adipose tissue (SAT) for flow cytometry immuno-profiling, with further blood samples after weight loss.Results: Peripheral blood MAIT cells were significantly reduced with greater activation in patients with advanced versus mild NAFLD or controls (0.8% vs 3.1%, 3.2% p < 0.05) although IFN gamma and TNF alpha expression was higher in all NAFLD MAIT cells (IL-17 in advanced) compared to control.In bariatric patients, Th1 (CD4 + CXCR3 + ) cells were more abundant in NASH vs no-NASH (33% vs 21% p < 0.05), particularly among patients with diabetes in whom pro-inflammatory Th1 and Th17 cells (CD4 + CD161 + ) expressed higher levels of liver homing CXCR6.After weight loss, the proportion of Th1, Th17 cells and activated (CD69 + ) CD8+ T cells reduced.The proportion of CXCR6 + Th1 and Th17 cells reduced, as did IFN gamma expressing CXCR6 + Th17 cells.In patients with T2DM NASH, intrahepatic Th17 cell numbers were higher and MAIT cells lower compared to other groups, with a similar reduction of MAIT cells in SAT.Conversely, SAT total T cell CXCR6 expression was higher in T2DM NASH than in other patient groups.In T2DM NASH, expression of tissue-retaining CD69 expression on Th1 cells was higher in the liver and lower in VAT.Conclusion: A peripheral and adipose tissue pro-inflammatory, liverhoming T cell phenotype is evident in patients with T2DM and NASH with improvement in this after weight loss.

Nonalcoholic fatty liver disease (NAFLD) is the major contributor to the global burden of chronic liver diseases and ranges from simple and reversible steatosis to nonalcoholic steatohepatitis (NASH), which may progress into cirrhosis and hepatocellular carcinoma (HCC). HCC represents the most common liver cancer, and it is a leading cause of death worldwide with an increasing trend for the future. Due to late diagnosis, non-responsiveness to systemic therapy, and high cancer heterogeneity, the treatment of this malignancy is challenging. To date, liver biopsy and ultrasound (US) are the gold standard procedures for HCC diagnosis and surveillance, although they are not suitable for mass screening. Therefore, it is impelling to find new, less invasive diagnostic strategies able to detect HCC at an early stage as well as monitor tumor progression and recurrence. Common and rare inherited variations that boost the switching from NASH to liver cancer may help to predict tumor onset. Furthermore, epigenetic changes which reflect intertumoral heterogeneity occur early in tumorigenesis and are highly stable under pathologic conditions. The severity of hepatic injuries can be detected through the analysis of cell circulating tumor DNAs (ctDNAs), microRNAs (miRNAs), and noncoding RNAs (ncRNAs), which are involved in several pathological processes that feature cancer, including cell growth, survival, and differentiation, thus representing appealing biomarkers for HCC. Therefore, this review discusses the current options for HCC surveillance, focusing on the role of genetic and epigenetic biomarkers as new strategies to refine HCC management.