Opportunities and barriers in omics-based biomarker discovery for steatotic liver diseases

Population screening for cirrhosis

In response to the growing health crisis of liver-related morbidity and mortality, screening for liver cirrhosis has emerged as a promising strategy for early detection and timely intervention. By identifying individuals with severe fibrosis or compensated cirrhosis, screening holds the promise of enhancing treatment outcomes, delaying disease progression, and ultimately improving the quality of life of affected individuals. Clinical practice guidelines from international scientific societies currently recommend targeted screening strategies, investigating high-risk populations with known risk factors of liver disease. While there is good evidence that screening increases case finding in the population, and a growing number of studies indicate that screening may motivate beneficial lifestyle changes in patients with steatotic liver disease, there are major gaps in knowledge in need of clarification before screening programs of cirrhosis are implemented. Foremost, randomized trials are needed to ensure that screening leads to improved liver-related morbidity and mortality. If not, screening for cirrhosis could be unethical due to overdiagnosis, overtreatment, increased health care costs, negative psychological consequences of screening, and futile invasive investigations. Moreover, the tests used for screening need to be optimized toward lower false positive rates than the currently used FIB-4 while retaining few false negatives. Finally, barriers to adherence to screening and implementation of screening programs need to be elucidated. This review provides a comprehensive overview of the current landscape of screening strategies for liver cirrhosis and the promises and pitfalls of current methods for early cirrhosis detection.

Liver macrophages revisited: The expanding universe of versatile responses in a spatiotemporal context

The liver is a vital organ that continuously adapts to a wide and dynamic diversity of self-antigens and xenobiotics. This involves the active contribution of immune cells, particularly by the liver-resident macrophages, the Kupffer cells (KCs), which exert a variety of central functions in liver homeostasis and disease. As such, KCs interact with their microenvironment to shape the hepatic cellular landscape, control gut-derived signal integration, and modulate metabolism. On injury, the rapid recruitment of bone marrow monocyte-derived macrophages alters this status quo and, when unrestrained, drastically compromises liver homeostasis, immune surveillance, and tissue organization. Several factors determine the functional roles of liver macrophages in these processes, such as their ontogeny, activation/polarization profile and, importantly, spatial distribution within the liver. Loss of tolerance and adaptability of the hepatic immune environment may result in persistent inflammation, hepatic fibrosis, cirrhosis, and a tumorigenic niche promoting liver cancer. In this review, we aim at providing the most recent breakthroughs in our understanding of liver macrophage biology, particularly their diversity and adaptability in the hepatic spatiotemporal context, as well as on potential therapeutic interventions that may hold the key to tackling remaining clinical challenges of varying etiologies in hepatology.