Liver injury in COVID-19: A minireview

Post-COVID metabolic enzyme alterations in K18-hACE2 mice exacerbate alcohol-induced liver injury through transcriptional regulation

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a significant threat to global public health. Despite reports of liver injury during viral disease, the occurrence and detailed mechanisms underlying the development of secondary exogenous liver injury, particularly in relation to changes in metabolic enzymes, remain to be fully elucidated. Therefore, this study was aimed to investigate the mechanisms underlying SARS-CoV-2-induced molecular alterations in hepatic metabolism and the consequent secondary liver injury resulting from alcohol exposure. We investigated the potential effects of SARS-CoV-2 infection on alcohol-induced liver injury in Keratin 18 promoter-human angiotensin converting enzyme 2 (K18-hACE2) transgenic mice. Mice were intranasally infected with 1 × 102 PFU of SARS-CoV-2. Following a 14 d recovery period from infection, the recovered mice were orally administered alcohol at 6 g/kg. Prior SARS-CoV-2 infection aggravated alcohol-induced liver injury based on increased alanine aminotransferase levels and cytoplasmic vacuolation. Interestingly, infected mice exhibited lower blood alcohol levels and higher levels of acetaldehyde, a toxic alcohol metabolite, compared to uninfected mice after the same period of alcohol consumption. Along with alterations of several metabolic process-related terms identified through RNA sequencing, notably, upregulation of cytochrome P450 2E1 (CYP2E1) and CYP1A2 was observed in infected mice compared to control value prior to alcohol exposure, with no significant impact of SARS-CoV-2 on intestinal damage. Tumor necrosis factor-alpha persistently showed upregulated expression in the infected mice; it also enhanced aryl hydrocarbon receptor and Sp1 expressions and their binding activity to Cyp1a2 and Cyp2e1 promoters, respectively, in hepatocytes, promoting the upregulation of their transcription. Our findings suggest that SARS-CoV-2 infection exacerbates alcohol-induced liver injury through the transcriptional activation of Cyp1a2 and Cyp2e1, providing valuable insights for the development of clinical recommendations on long COVID.

Hepatobiliary long-term consequences of COVID-19: dramatically increased rate of secondary sclerosing cholangitis in critically ill COVID-19 patients

BACKGROUND

Increasing evidence suggests that secondary sclerosing cholangitis (SSC), which can lead to cirrhosis or liver failure, may be a hepatobiliary long-term complication of COVID-19. The aim of this study was to estimate the frequency and outcome of this COVID-19 sequela and to identify possible risk factors.

METHODS

This observational study, conducted at University Hospital Charité Berlin and Unfallkrankenhaus Berlin, Germany, involved hospitalized patients with COVID-19 pneumonia, including 1082 ventilated COVID-19 patients. We compared COVID-19 patients who developed SSC with a COVID-19 control group by univariate and multivariate analyses.

RESULTS

SSC occurrence after COVID-19 was observed exclusively in critically ill patients with invasive ventilation, albeit with extreme clustering among them. One in every 43 invasively ventilated COVID-19 patients developed this complication. Risk factors preceding the development of secondary sclerosing cholangitis in critically ill COVID-19 patients (SSC-CIP) were signs of systemic reduced blood oxygen supply (e.g., low PaO2/FiO2, ischemic organ infarctions), multi-organ failure (high SOFA score) at admission, high fibrinogen levels and intravenous ketamine use. Multivariate analysis confirmed fibrinogen and increased plasma lactate dehydrogenase as independent risk factors associated with cholangiopathy onset. The 1-year transplant-free survival rate of COVID-19-associated SSC-CIP was 40%.

CONCLUSIONS

COVID-19 causes SSC-CIP in a substantial proportion of critically ill patients. SSC-CIP most likely develops due to severe tissue hypoxia and fibrinogen-associated circulatory disturbances. A significant increase of patients with SSC-CIP is to be expected in the post-COVID era.

The impact of COVID-19 on liver injury in various age

The coronavirus disease 2019 (COVID-19) disease was first detected in December 2019 in Wuhan, China. This disease is currently one of the most important global health problems. The novel coronavirus COVID-19 is a respiratory illness, that has caused a deadly pandemic that is spreading rapidly around the world. It is not only a respiratory system virus that causes severe lung disease, but also a systemic disease agent that can affect all systems. People with COVID-19 disease usually have respiratory signs, however, the liver disorder is not an uncommon presentation. In addition, many studies around the world have revealed that the liver is injured to various degrees in patients with severe acute respiratory syndrome coronavirus 2 disease. This review mainly focuses on the impact of COVID-19 on Liver Injury at various ages.

Implications of metabolic dysfunction associated fatty liver disease in COVID-19

Metabolic associated fatty liver disorder (MAFLD) characterizes the contributing etiologies (i.e., type 2 diabetes mellitus, metabolic syndrome, overweight) of individuals with fatty liver disease that affects 1/3^rd of the world population. In 2020, the coronavirus disease 2019 (COVID-19) crisis was unprecedented, and people with different comorbidities became more susceptible to the infection caused by severe acute respiratory syndrome coronavirus 2. MAFLD patients are frequently obese with added metabolic menace like diabetes, hypertension, and dyslipidemia leading to greater jeopardy of COVID-19. MAFLD patients are 4 to 6-fold more prone towards infections. COVID-19 induces liver injury with elevated levels of aspartate aminotransferase and alanine aminotransferase and insignificantly elevated bilirubin. Hence, MAFLD in COVID-19 patients worsens the condition significantly. The evidence highlighting the interaction between MAFLD and altered liver functioning in COVID-19 suggested that COVID-19 patients with pre-existing MAFLD are at greater risk of morbidity or intensive care unit admission. Direct hepatic injury, enhanced levels of inflammatory cytokines, declined hepatic mitochondrial activity, and compromised immunity are considered as some underlying mechanisms. The main focus of this review is to discuss the implications of metabolic dysfunction associated with fatty liver disease in COVID-19 patients. The review systematically analyzes the effect of striking two worldwide pandemics (MAFLD and COVID-19) together in the present era.

Liver injury in COVID-19 patients with non-alcoholic fatty liver disease: an update

The coronavirus disease 2019 (COVID-19) pandemic has revolutionized the priorities of the medical society worldwide. Although most patients infected with SARS-CoV-2 exhibit respiratory symptoms, other organs may also be involved, including the liver, often resulting in liver injury. Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, and its prevalence is expected to increase together with the epidemics of type 2 diabetes and obesity. Data about liver injury during COVID-19 are numerous, while overviews of this infection in patients with NAFLD, both in terms of respiratory and liver, are emerging. In this review, we summarise the current research focusing on COVID-19 in NAFLD patients and discuss the association between liver injury in COVID-19 subjects and non-alcoholic fatty liver disease.

Liver damage in patients with COVID-19

The clinical spectrum of SARS-CoV-2 infection continues to expand, raising important fundamental issues regarding the SARS-CoV-2 cellular tropism and pathogenic mechanisms. Liver damage is observed in patients with all forms of COVID-19, especially severe and critical forms, which could be due to the direct viral damage, immune dysregulation (systemic inflammatory response and cytokine storm), hypoxia-ischemia, drug-induced hepatotoxicity, and concomitant chronic disorders. Liver damage, defined primarily by elevated transaminase levels, is often observed in patients with COVID-19 and correlates with clinical outcomes, including mortality. Diagnostic criteria, pathogenesis, clinical characteristics, treatment, and prognosis of liver injury in COVID-19 should be clarified in further clinical trials. Currently, there is a critical shortage of proven treatment options for patients with COVID-19, resulting in an urgent need to study the multiple organ failure and liver damage pathogenesis in patients with this disease. The review provides information about the pathophysiological mechanisms of the SARS-CoV-2-induced liver damage and the development of liver failure in COVID-19. Information sources were searched in the PubMed database using the keywords “liver damage in COVID-19” and “immune liver damage in COVID-19”.

COVID-19 status quo: Emphasis on gastrointestinal and liver manifestations

The coronavirus disease 2019 (COVID-19) has caused one of the worst public health crises in modern history. Even though severe acute respiratory syndrome coronavirus 2 primarily affects the respiratory tract, gastrointestinal manifestations are well described in literature. This review will discuss the epidemiology, virology, manifestations, immunosuppressant states, and lessons learned from COVID-19. Observations: At the time of writing, COVID-19 had infected more than 111 million people and caused over 2.5 million deaths worldwide. Multiple medical comorbidities including obesity, pre-existing liver condition and the use of proton pump inhibitor have been described as risk factor for severe COVID-19. COVID-19 most frequently causes diarrhea (12.4%), nausea/vomiting (9%) and elevation in liver enzymes (15%-20%). The current data does not suggest that patients on immunomodulators have a significantly increased risk of mortality from COVID-19. The current guidelines from American Gastroenterological Association and American Association for the Study of Liver Diseases do not recommend pre-emptive changes in patients on immunosuppression if the patients have not been infected with COVID-19. Conclusions and relevance: The COVID-19 pandemic has prompted a change in structure and shape of gastroenterology departmental activities. Endoscopy should be performed only when necessary and with strict protective measures. Online consultations in the form of telehealth services and home drug deliveries have revolutionized the field.

Review of COVID-19, part 1: Abdominal manifestations in adults and multisystem inflammatory syndrome in children

The coronavirus disease 2019 (COVID -19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world, resulting in severe morbidity, mortality and economic hardship, and altering the landscape of healthcare forever. Although primarily a pulmonary illness, it can affect multiple organ systems throughout the body, sometimes with devastating complications and long-term sequelae. As we move into the second year of this pandemic, a better understanding of the pathophysiology of the virus and the varied imaging findings of COVID-19 in the involved organs is crucial to better manage this complex multi-organ disease and to help improve overall survival. This manuscript provides a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19 with the exception of unique cardiothoracic features associated with multisystem inflammatory syndrome in children (MIS-C). In Part I, extra-thoracic manifestations of COVID-19 in the abdomen in adults and features of MIS-C will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

Drugs and liver injury: a not to be overlooked binomial in COVID-19

SARS-CoV-2 infection (COVID-19) results predominantly in pulmonary involvement but a direct, virus-induced liver damage may also occur, whose mechanisms are being actively investigated. Accordingly, it appears of utmost importance to monitor liver function and carefully evaluate hepatic safety of the various drugs administered during COVID-19. In this respect, many drugs, biological agents and novel molecules, whose efficacy in COVID-19 is under scrutiny, have also been shown to potentially cause or worsen liver damage. In this article, we review safety data of established as well as promising agents for COVID-19.

Non-Alcoholic Fatty Liver Disease and COVID-19-Two Pandemics Hitting at the Same Time

The COVID-19 pandemic was and still is a global burden with more than 178,000,000 cases reported so far. Although it mainly affects respiratory organs, COVID-19 has many extrapulmonary manifestations, including, among other things, liver injury. Many hypotheses have been proposed to explain direct and indirect impacts of the SARS-CoV-2 virus on the liver. Studies have shown that around 15–30% of patients with COVID-19 have underlying liver disease, and 20–35% of patients with COVID-19 had altered liver enzymes at admission. One of the hypotheses is reactivation of an underlying liver disease, such as non-alcoholic fatty liver disease (NAFLD). Some studies have shown that NAFLD is associated with severe COVID-19 and poor outcome; nevertheless, other studies showed no significant difference between groups in comparing complications and clinical outcomes. Patients with NAFLD may suffer severe COVID-19 due to other comorbidities, especially cardiovascular diseases. The link between NAFLD and COVID-19 is not clear yet, and further studies and research are needed.

Liver function test abnormalities at hospital admission are associated with severe course of SARS-CoV-2 infection: a prospective cohort study

OBJECTIVE

Liver injury has frequently been reported in COVID-19 patients. The clinical relevance of liver injury related to SARS-CoV-2 infection remains unclear with a need for prospective studies on the impact of liver function test (LFT) abnormalities at baseline.

DESIGN

Data of 217 patients without pre-existing liver disease prospectively included in the COVID-19 registry of the LMU university hospital were analysed in order to assess the association of abnormal LFT at admission and course of the disease. Severe course was defined as admission to the intensive care unit (ICU) or as COVID-19-related death.

RESULTS

Abnormal LFT at baseline was present in 58% of patients, with a predominant elevation of aspartate aminotransferase (AST) (42%), gamma-glutamyltransferase (GGT) (37%) and alanine aminotransferase (ALT) (27%), hypoalbuminaemia was observed in 33%. Elevation of ALT and GGT, as well as hypoalbuminaemia, was associated with higher proportions of patients requiring ICU treatment and mechanical ventilation. After adjusting for age, gender and comorbidities, hypoalbuminaemia combined with abnormal AST or GGT at hospital admission was a highly significant independent risk factor for ICU admission (OR 46.22 and 38.8, respectively) and for a composite endpoint of ICU admission and/or COVID-19-related death (OR 42.0 and 26.9, respectively).

CONCLUSION

Abnormal LFTs at hospital admission, in particular GGT and albumin, are associated with a severe course of SARS-CoV-2 infection.

Liver transplantation during global COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory disease respiratory syndrome coronavirus-2 has significantly impacted the health care systems globally. Liver transplantation (LT) has faced an unequivocal challenge during this unprecedented time. This targeted review aims to cover most of the clinical issues, challenges and concerns about LT during the COVID-19 pandemic and discuss the most updated literature on this rapidly emerging subject.

Abnormal Liver Biochemistry Tests and Acute Liver Injury in COVID-19 Patients: Current Evidence and Potential Pathogenesis

Globally, millions of persons have contracted the coronavirus disease 2019 (COVID-19) over the past several months, resulting in significant mortality. Health care systems are negatively impacted including the care of individuals with cancers and other chronic diseases such as chronic active hepatitis, cirrhosis and hepatocellular carcinoma. There are various probable pathogenic mechanisms that have been presented to account for liver injury in COVID-19 patients such as hepatotoxicity cause by therapeutic drugs, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of the bile duct cells and hepatocytes, hypoxia and systemic inflammatory response. Liver biochemistry tests such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) are deranged in COVID-19 patients with liver injury. Hepatocellular damage results in the elevation of serum AST and ALT levels in early onset disease while a cholestatic pattern that develops as the disease progress causes higher levels of ALP, GGT, direct and total bilirubin. These liver biochemistry tests are prognostic markers of disease severity and should be carefully monitored in COVID-19 patients. We conducted a systematic review of abnormal liver biochemistry tests in COVID-19 and the possible pathogenesis involved. Significant findings regarding the severity, hepatocellular pattern, incidence and related clinical outcomes in COVID-19 patients are highlighted.

Mesenchymal stromal cell secretome in liver failure: Perspectives on COVID-19 infection treatment

Due to their immunomodulatory potential and release of trophic factors that promote healing, mesenchymal stromal cells (MSCs) are considered important players in tissue homeostasis and regeneration. MSCs have been widely used in clinical trials to treat multiple conditions associated with inflammation and tissue damage. Recent evidence suggests that most of the MSC therapeutic effects are derived from their secretome, including the extracellular vesicles, representing a promising approach in regenerative medicine application to treat organ failure as a result of inflammation/fibrosis. The recent outbreak of respiratory syndrome coronavirus, caused by the newly identified agent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has forced scientists worldwide to use all available instruments to fight the infection, including the inflammatory cascade caused by this pandemic disease. The use of MSCs is a valid approach to combat organ inflammation in different compartments. In addition to the lungs, which are considered the main inflammatory target for this virus, other organs are compromised by the infection. In particular, the liver is involved in the inflammatory response to SARS-CoV-2 infection, which causes organ failure, leading to death in coronavirus disease 2019 (COVID-19) patients. We herein summarize the current implications derived from the use of MSCs and their soluble derivatives in COVID-19 treatment, and emphasize the potential of MSC-based therapy in this clinical setting.