Opinion Review
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Sep 27, 2021; 13(9): 969-978
Published online Sep 27, 2021. doi: 10.4254/wjh.v13.i9.969
Coronavirus disease 2019 and non-alcoholic fatty liver disease
Francesco Bellanti, Gianluigi Vendemiale
Francesco Bellanti, Gianluigi Vendemiale, Department of Medical and Surgical Sciences, University of Foggia, Foggia 71122, Italy
Author contributions: All authors wrote, revised and approved the final manuscript.
Conflict-of-interest statement: Authors declare no conflict of interests for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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/
Corresponding author: Francesco Bellanti, MD, PhD, Doctor, Associate Professor, Department of Medical and Surgical Sciences, University of Foggia, Viale Pinto, 1, Foggia 71122, Italy. francesco.bellanti@unifg.it
Received: May 28, 2021
Peer-review started: May 28, 2021
First decision: July 6, 2021
Revised: July 15, 2021
Accepted: August 11, 2021
Article in press: August 11, 2021
Published online: September 27, 2021
Abstract

The coronavirus disease 2019 (COVID-19) pandemic may present with a broad range of clinical manifestations, from no or mild symptoms to severe disease. Patients with specific pre-existing comorbidities, such as obesity and type 2 diabetes, are at high risk of coming out with a critical form of COVID-19. Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and, because of its frequent association with metabolic alterations including obesity and type 2 diabetes, it has recently been re-named as metabolic-associated fatty liver disease (MAFLD). Several studies and systematic reviews pointed out the increased risk of severe COVID-19 in NAFLD/MAFLD patients. Even though dedicated mechanistic studies are missing, this higher probability may be justified by systemic low-grade chronic inflammation associated with immune dysregulation in NAFLD/MAFLD, which could trigger cytokine storm and hypercoagulable state after severe acute respiratory syndrome coronavirus 2 infection. This review focuses on the predisposing role of NAFLD/MAFLD in favoring severe COVID-19, discussing the available information on specific risk factors, clinical features, outcomes, and pathogenetic mechanisms.

Keywords: Non-alcoholic fatty liver disease, Metabolic-associated fatty liver disease, COVID-19, SARS-CoV-2, Liver injury, Immune dysregulation

Core Tip: Non-alcoholic fatty liver disease is the most widespread hepatic disorder. Recently re-named as metabolic-associated fatty liver disease, it has been lately pointed out as a predisposing factor for severe coronavirus disease 2019 (COVID-19). We herein discuss the epidemiology and possible underlying pathways predisposing severe COVID-19 in non-alcoholic fatty liver disease/metabolic-associated fatty liver disease patients.