Screening and follow-up of chronic liver diseases with understanding their etiology in clinics and hospitals

Fibulin-4 as a potential extracellular vesicle marker of fibrosis in patients with cirrhosis

Chronic liver injury leads to decreased liver function and increased fibrosis. Fibrosis is not only associated with the development of portal hypertension and carcinogenesis, but with the occurrence of events and a poor prognosis, highlighting the importance of non-invasive fibrosis assessment in patients. In the present study, we searched for markers related to liver fibrosis via proteomic analysis of small extracellular vesicles (sEVs). In the discovery cohort, proteomic analysis was carried out in the sEVs extracted from the sera of 5 patients with decompensated cirrhosis, 5 patients with compensated cirrhosis, and 5 controls without liver disease. Interestingly, in this cohort, fibulin-4 was significantly associated with cirrhosis while in the validation cohort [formed by 191 patients: 7 patients without disease, 16 patients without liver disease (other diseases), 38 patients with chronic liver disease (CLD), 75 patients with cirrhosis of Child-Pugh class A (36 without hepatocellular carcinoma [HCC], 29 with HCC), and 65 patients with cirrhosis of Child-Pugh class B-C (39 without HCC, 26 with HCC)], fibulin-4/CD9 levels increased with cirrhosis progression. Furthermore, the fibulin-4/CD9 ratio was significantly higher in patients with varices. Immunostaining also revealed strong fibulin-4 expression in cholangiocytes within the fibrous areas and mesothelial cells in liver tissue blood vessels. Taken together, our results suggest that fibulin-4, essential for lysyl oxidase activation, might be a new liver fibrosis marker found in the sEVs of patients with cirrhosis.

Long-term prediction of hepatocellular carcinoma using serum autotaxin levels after antiviral therapy for hepatitis C

INTRODUCTION AND OBJECTIVES

Continuous monitoring for hepatocellular carcinoma is necessary following treatment with direct-acting antivirals in patients with hepatitis C virus infection. We investigated whether the long-term follow-up of serum autotaxin levels could predict the development of hepatocellular carcinoma.

PATIENTS AND METHODS

This prospective observational study enrolled adult patients with chronic hepatitis C virus infection who presented to the study center from January 2016 to March 2021. Among the patients who achieved a sustained viral response, the relationship between the development of hepatocellular carcinoma and serum autotaxin levels was assessed before treatment with direct-acting antivirals; at the end of therapy; at 12 and 24 weeks; and at 12, 24, 36, and 48 months after treatment.

RESULTS

Data were analyzed for 139 patients. Thirteen patients developed hepatocellular carcinoma 48 months after treatment. The cut-off serum autotaxin values that predicted hepatocellular carcinoma after 24 weeks were 1.22 (men) and 1.92 (women) mg/L. The area under the curve for serum autotaxin was 0.83 (95% confidence interval [CI]:0.71-0.95) in men and 0.90 (95% CI: 0.82-0.99) in women. The positive predictive value of serum autotaxin was 0.208 (95% CI: 0.139-0.248), and the negative predictive value was 0.971 (95% CI: 0.939-0.990). The cumulative incidence of hepatocellular carcinoma was significantly higher when serum autotaxin levels were above the cut-off value after 24 weeks (p < 0.0001).

CONCLUSIONS

Serum autotaxin is a candidate biomarker for predicting hepatocellular carcinoma during the long-term follow-up of patients with a sustained viral response following treatment with direct-acting antivirals.

Transition of clinical and basic studies on liver cirrhosis treatment using cells to seek the best treatment

The liver is a highly regenerative organ; however, its regeneration potential is reduced by chronic inflammation with fibrosis accumulation, leading to cirrhosis. With an aim to tackle liver cirrhosis, a life-threatening disease, trials of autologous bone marrow cell infusion (ABMi) therapy started in 2003. Clinical studies revealed that ABMi attenuated liver fibrosis and improved liver function in some patients; however, this therapy has some limitations such as the need of general anesthesia. Following ABMi therapy, studies have focused on specific cells such as mesenchymal stromal cells (MSCs) from a variety of tissues such as bone marrow, adipose tissue, and umbilical cord tissues. Particularly, studies have focused on gaining mechanistic insights into MSC distribution and effects on immune cells, especially macrophages. Several basic studies have reported the use of MSCs for liver cirrhosis models, while a number of clinical studies have used autologous and allogeneic MSCs; however, there are only a few reports on the obvious substantial effect of MSCs in clinical studies. Since then, studies have analyzed and identified the important signals or components in MSCs that regulate immune cells, such as macrophages, under cirrhotic conditions and have revealed that MSC-derived exosomes are key regulators. Researchers are still seeking the best approach and filling the gap between basic and clinical studies to treat liver cirrhosis. This paper highlights the timeline of basic and clinical studies analyzing ABMi and MSC therapies for cirrhosis and the scope for future studies and therapy.

Diagnosis and Therapeutic Management of Liver Fibrosis by MicroRNA

Remarkable progress has been made in the treatment and control of hepatitis B and C viral infections. However, fundamental treatments for diseases in which liver fibrosis is a key factor, such as cirrhosis, alcoholic/nonalcoholic steatohepatitis, autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, are still under development and remain an unmet medical need. To solve this problem, it is essential to elucidate the pathogenesis of liver fibrosis in detail from a molecular and cellular perspective and to develop targeted therapeutic agents based on this information. Recently, microRNAs (miRNAs), functional RNAs of 22 nucleotides, have been shown to be involved in the pathogenesis of liver fibrosis. In addition, extracellular vesicles called "exosomes" have been attracting attention, and research is being conducted to establish noninvasive and extremely sensitive biomarkers using miRNAs in exosomes. In this review, we summarize miRNAs directly involved in liver fibrosis, miRNAs associated with diseases leading to liver fibrosis, and miRNAs related to complications of cirrhosis. We will also discuss the efficacy of each miRNA as a biomarker of liver fibrosis and pathology, and its potential application as a therapeutic agent.