Published online Dec 28, 2017. doi: 10.3748/wjg.v23.i48.8439
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
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.
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.