Editorial
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2017; 23(48): 8439-8442
Published online Dec 28, 2017. doi: 10.3748/wjg.v23.i48.8439
Serum levels of angiotensin converting enzyme as a biomarker of liver fibrosis
Aline Silva Miranda, Ana Cristina Simões e Silva
Aline Silva Miranda, Ana Cristina Simões e Silva, Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG 30130-100, Brazil
Aline Silva Miranda, Laboratory of Neurobiology, Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG 30130-100, Brazil
Ana Cristina Simões e Silva, Department of Pediatrics, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG 30130-100, Brazil
Author contributions: Miranda AS and Simões e Silva AC designed the article, performed literature search, and wrote and reviewed the paper.
Supported by CNPq, No. 460334/2014-0; FAPEMIG, No. CDS - PPM-00555-15 (to Simoes e Silva AC); and 2016 NARSAD Young Investigator Grant Awardee from the Brain and Behavior Research Foundation, No. 25414 (to Miranda AS).
Conflict-of-interest statement: Miranda AS and Simões e Silva AC declare no conflict of interest related to this publication.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Ana Cristina Simões e Silva, MD, PhD, Professor, Department of Pediatrics, Interdisciplinary Laboratory of Medical Investigation, Faculty of Medicine, UFMG, Alfredo Balena Avenue, Number 190, 2nd floor, Room #281, Belo Horizonte, MG 30130-100, Brazil. acssilva@hotmail.com
Telephone: +55-31-34098073 Fax: +55-31-34099770
Received: October 30, 2017
Peer-review started: October 31, 2017
First decision: November 22, 2017
Revised: December 4, 2017
Accepted: December 13, 2017
Article in press: December 13, 2017
Published online: December 28, 2017
Abstract

The renin angiotensin system (RAS) is classically conceived as a circulating hormonal system involved in blood pressure control and hydroelectrolyte balance. The discovery that RAS components are locally expressed in a wide range of organs and tissues, including the liver, pointed to a role for this system in the pathogenesis of several conditions including hepatic fibrosis and cirrhosis. It has been widely reported that the classical RAS axis composed by the angiotensin converting enzyme (ACE)-angiotensin (Ang) II-Ang type 1 (AT1) receptor mediates pro-inflammatory, pro-thrombotic, and pro-fibrotic processes. On the other hand, the alternative axis comprising ACE2-Ang-(1-7)-Mas receptor seems to play a protective role by frequently opposing Ang II action. Chronic hepatitis B (CHB) is one of the leading causes of liver fibrosis, accounting for the death of nearly one million people worldwide. Liver fibrosis is a key factor to determine therapeutic interventions for patients with CHB. However, the establishment of non-invasive and accurate methods to detect reversible stages of liver fibrosis is still a challenge. In an elegant study published in the 36th issue of the World Journal of Gastroenterology, Noguchi et al showed the predictive value of serum ACE levels in detecting not only advanced stages of liver fibrosis but also initial and intermediate fibrotic stages. The serum levels of ACE might represent an accurate, non-invasive, widely available, and easy method to evaluate fibrosis related to CHB. Moreover, therapies involving the inhibition of the classical RAS axis components might be promising in the control of CHB-related liver fibrosis.

Keywords: Renin angiotensin system, Angiotensin converting enzyme, Angiotensin II, Angiotensin-(1-7), Chronic hepatitis B, Hepatic cirrhosis, Liver fibrosis

Core tip: The therapeutic intervention for patients with chronic hepatitis B frequently relies on the pathological classification of liver fibrosis severity in biopsy. The establishment of non-invasive and accurate methods to detect reversible stages of liver fibrosis is still a challenge. High serum levels of angiotensin converting enzyme seem to better predict intermediate liver fibrosis than other classical fibrotic markers. Non-invasive methods to detect intermediate stages of liver fibrosis with very good accuracy may permit the introduction and/or evaluation of treatments during reversible stages of the disease. Further studies are urgently necessary to fully clarify the role of RAS components in liver disease.