Preface

*Advances in Hepatology* presents new achievements in the clinical management of chronic liver disease patients, including effective treatments for chronic infection mainly related to the hepatitis C virus (HCV). It examines the relationship between obesity and liver diseases such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). To prevent and treat deleterious liver effects, bariatric surgery may be indicated in selected patients, which the book also discusses.

The development of direct-acting antiviral (DAA) agents for the treatment of HCV infection has completely transformed the management of this disease in the last decade. The advantages of using DAA therapies include high efficacy (sustained virological response (SVR) rate > 95%) with minimal side effects, good tolerability, easy drug administration (once-daily oral dosing), and short duration of treatment (8–12 weeks).

Hepatitis C is a high-prevalence disease, representing a global impact health problem. Lately, many changes have been made in treatment guidelines because of the commercialization of second-generation DAAs due to their high effectiveness, few side effects, and pangenotypic action.

In one recently published study (Liver Int. 2021;41: 456-73) using a mathematical program, the authors evaluated the possibilities of the complete elimination of HCV from the world by the end of 2030, as defined by the World Health Organization (WHO), considering that is attainable with the availability of highly efficacious therapies. This study reports progress made in the timing of HCV elimination in forty-five high-income countries between 2017 and 2019.

Disease progression models of HCV infection for each country were updated with the latest data on chronic HCV prevalence and annual diagnosis and treatment levels, assumed to remain constant in the future. Modeled outcomes were analyzed to determine the year in which each country would meet the WHO 2030 elimination targets.

Of the forty-five countries studied, eleven (Australia, Canada, France, Germany, Iceland, Italy, Japan, Spain, Sweden, Switzerland, and United Kingdom) are on track to meet the WHO's elimination targets by 2030; five countries (Austria, Malta, Netherlands, New Zealand, and South Korea) by 2040; and two (Saudi Arabia and Taiwan) by 2050. The remaining twenty-seven countries are not expected to achieve this elimination before 2050. Compared to progress in 2017, South Korea is no longer on track to eliminate HCV by 2030, three countries (Canada, Germany, and Sweden) are now on track, and most countries (thirty in total) saw no change.

The authors conclude that assuming high-income countries will maintain current levels of diagnosis and treatment, only 24% are on track to eliminate HCV by 2030, and 60% are off track by at least twenty years. If current levels of diagnosis and treatment continue falling, achieving the WHO's 2030 targets will be more challenging. With less than ten years remaining, screening and treatment expansion is crucial.

In relation to benefits obtained in the treatment of hepatocellular carcinoma (HCC) patients with DAA agents, the current opinion is that the risk may persist up to ten years after obtaining an effective sustained viral response (SVR) with complete disappearance of this virus from the human body because HCV infection appears to leave behind an epigenetic scar, inducing carcinogenesis.

The discrepancy between the number of potentially available kidneys and the number of patients listed for kidney transplant continues to widen all over the world. Transplantation of kidneys from HCV-infected donors into HCV-naïve recipients has increased recently because of persistent kidney shortage and the availability of DAA agents. This strategy has the potential to reduce waiting times for transplants as well as the risk of mortality in dialysis.

The many possibilities of eliminating HCV infection with different types of treatment and the expectation of new vaccines in the near future have the potential to cure this chronic viral infection in different settings and circumstances with possible eradication in the future.

> **Luis Rodrigo MD** Professor, School of Medicine, University of Oviedo, Oviedo, Asturias, Spain

**Ian Martins** Independent Scientist, Australia

**1**

Section 1

Discovery of Hepatitis C

Virus

#### **Xiaozhong Guo and Xingshun Qi**

General Hospital of Northern Theater Command, China

### Section 1
