Retrospective Cohort Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 21, 2022; 28(39): 5735-5749
Published online Oct 21, 2022. doi: 10.3748/wjg.v28.i39.5735
Effects of COVID-19 on the liver: The experience of a single center
Valentina Liakina, Ieva Stundiene, Gabriele Milaknyte, Ramune Bytautiene, Rosita Reivytyte, Roma Puronaite, Gintare Urbanoviciute, Edita Kazenaite
Valentina Liakina, Ieva Stundiene, Gabriele Milaknyte, Ramune Bytautiene, Edita Kazenaite, Centre of Hepatology, Gastroenterology and Dietetics, Clinic of Gastroenterology, Nephrourology and Surgery, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius 01513, Lithuania
Valentina Liakina, Department of Chemistry and Bioengineering, Faculty of Fundamental Sciences, VILNIUS TECH, Vilnius 10223, Lithuania
Rosita Reivytyte, Gintare Urbanoviciute, Faculty of Medicine, Vilnius University, Vilnius 01513, Lithuania
Roma Puronaite, Clinic of Cardiac and Vascular Diseases, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius 01513, Lithuania
Roma Puronaite, Institute of Data Science and Digital Technologies, Faculty of Mathematics and Informatics, Vilnius University, Vilnius 01513, Lithuania
Edita Kazenaite, Department of Pathology, Forensic Medicine and Pharmacology, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius 01513, Lithuania
Author contributions: Puronaite R, Milaknyte G, Reivytyte R and Urbanoviciute G performed raw data collection; Liakina V, Stundiene I, Bytautiene R and Kazenaite E revised collected data for relevance and sufficiency; Liakina V, Stundiene I, Milaknyte G and Bytautiene R wrote the manuscript draft; Liakina V edited draft and prepared the final version of the manuscript; Kazenaite E revised manuscript for important intellectual content.
Institutional review board statement: The study was reviewed and approved by the Vilnius Regional Biomedical Research Ethics Committee and by Institutional Review Board (approval No. 2022/2-1411-882).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous data that were obtained after each patients agreed to treatment by written consent.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
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:
Corresponding author: Valentina Liakina, PhD, Senior Research Fellow, Centre of Hepatology, Gastroenterology and Dietetics, Clinic of Gastroenterology, Nephrourology and Surgery, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, 3 Universiteto Street, Vilnius 01513, Lithuania.
Received: June 22, 2022
Peer-review started: June 22, 2022
First decision: August 1, 2022
Revised: August 12, 2022
Accepted: September 21, 2022
Article in press: September 21, 2022
Published online: October 21, 2022
Research background

Alongside respiratory symptoms, elevated liver enzymes, abnormal liver function, and even acute liver failure were reported in patients suffering from severe acute respiratory disease coronavirus 2 (SARS-CoV-2) pneumonia. However, the exact triggers of liver damage, how it affects patients, and whether it could predict the course and outcomes of coronavirus disease 2019 (COVID-19) itself remain unclear.

Research motivation

Although liver injury in patients with COVID-19 is often transient and is usually normalized without special treatment in mild cases of the disease, it can be the first sign of life-threatening events such as acute liver failure in severe and critical cases. Therefore, it is essential for everyday clinical practice to have a more precise view of how the liver impairment affects the course and outcomes of SARS-CoV-2 infection itself. Our study contributes to this goal.

Research objectives

This study aims to analyze the impact of liver enzyme abnormalities on the severity and outcomes of COVID-19 in hospitalized patients to have a clearer view of how to evaluate the risk of severe liver impairment from elevated enzyme tests.

Research methods

In this study, 684 depersonalized medical records from patients hospitalized with COVID-19 during the 2020-2021 period were analyzed. Patients were assigned to two groups: those with elevated liver enzymes, where at least one out of four liver enzymes were elevated at any point of hospitalization, from admission to discharge; and the control group, with normal liver enzymes during hospitalization. COVID-19 severity was assessed according to the interim World Health Organization guidance (2022). Data on viral pneumonia complications, laboratory tests, and underlying diseases were also collected and analyzed.

Research results

In total, 88.2% of patients with SARS-CoV-2 infection produced abnormal liver test results. Alanine aminotransferase and aspartate aminotransferase levels were elevated by a factor of less than 3 in 54.9% and 74.8% of cases with increased enzyme levels, respectively. Patients in Group 1 had almost double the chance of bacterial viral pneumonia complications, required oxygen supply more often, and displayed higher biochemical inflammation indices than those in Group 2. Like in other research, our patients rarely experienced acute liver failure. The majority of the deceased patients had at least one underlying disease or a combination thereof, and most were male. Alongside male gender and older age, diabetes and hyperlipidemia, but not obesity, were confirmed as independent factors associated with more a severe COVID-19 infection in our cohort.

Research conclusions

In our study, the presence of liver impairment allows us to predict a more severe inflammation with a higher risk of bacterial complication and worse outcomes of COVID-19. Therefore, monitoring liver enzyme levels should be a part of the qualitative care of patients with SARS-CoV-2 pneumonia.

Research perspectives

To find out more precisely the sources of increased liver enzymes in patients with COVID-19, it would be beneficial to elucidate whether the SARS-CoV-2 virus can enter and replicate in hepatocytes. For this purpose, an experimental study on the cell line of the liver origin or virus detection in hepatocytes during a histological analysis of autopsies could be promising.