Progressive cholestasis and associated sclerosing cholangitis are frequent complications of COVID-19 in patients with chronic liver disease

Hepatic angiotensin-converting enzyme 2 expression in metabolic dysfunction-associated steatotic liver disease and in patients with fatal COVID-19

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD), characterised by hepatic lipid accumulation, causes inflammation and oxidative stress accompanied by cell damage and fibrosis. Liver injury (LI) is also frequently reported in patients hospitalised with coronavirus disease 2019 (COVID-19), while pre-existing MASLD increases the risk of LI and the development of COVID-19-associated cholangiopathy. Mechanisms of injury at the cellular level remain unclear, but it may be significant that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19, uses angiotensin-converting expression enzyme 2 (ACE2), a key regulator of the ‘anti-inflammatory’ arm of the renin-angiotensin system, for viral attachment and host cell invasion.

AIM

To determine if hepatic ACE2 levels are altered during progression of MASLD and in patients who died with severe COVID-19.

METHODS

ACE2 protein levels and localisation, and histological fibrosis and lipid droplet accumulation as markers of MASLD were determined in formalin-fixed liver tissue sections across the MASLD pathological spectrum (isolated hepatocellular steatosis, metabolic dysfunction-associated steatohepatitis (MASH) +/- fibrosis, end-stage cirrhosis) and in post-mortem tissues from patients who had died with severe COVID-19, using ACE2 immunohistochemistry and haematoxylin and eosin and picrosirius red staining of total collagen and lipid droplet areas, followed by quantification using machine learning-based image pixel classifiers.

RESULTS

ACE2 staining is primarily intracellular and concentrated in the cytoplasm of centrilobular hepatocytes and apical membranes of bile duct cholangiocytes. Strikingly, ACE2 protein levels are elevated in non-fibrotic MASH compared to healthy controls but not in the progression to MASH with fibrosis and in cirrhosis. ACE2 protein levels and histological fibrosis are not associated, but ACE2 and liver lipid droplet content are significantly correlated across the MASLD spectrum. Hepatic ACE2 levels are also increased in COVID-19 patients, especially those showing evidence of LI, but are not correlated with the presence of SARS-CoV-2 virus in the liver. However, there is a clear association between the hepatic lipid droplet content and the presence of the virus, suggesting a possible functional link.

CONCLUSION

Hepatic ACE2 levels were elevated in nonfibrotic MASH and COVID-19 patients with LI, while lipid accumulation may promote intra-hepatic SARS-CoV-2 replication, accelerating MASLD progression and COVID-19-mediated liver damage.

Rapid improvement of hepatic steatosis and liver stiffness after metabolic/bariatric surgery: a prospective study

Metabolic dysfunction-associated steatotic liver disease (MASLD) and related steatohepatitis (MASH) are common among obese patients and may improve after metabolic/bariatric surgery (MBS). 93 Patients undergoing MBS in 2021-2022 were prospectively enrolled. Liver stiffness measurement (LSM; via vibration-controlled transient elastography [VCTE], point [pSWE] and 2D [2DSWE] shear wave elastography) and non-invasive steatosis assessment (via controlled attenuation parameter [CAP]) were performed before (baseline [BL]) and three months (M3) after surgery. 93 patients (median age 40.9 years, 68.8% female, median BL-BMI: 46.0 kg/m2) were included. BL-liver biopsy showed MASLD in 82.8% and MASH in 34.4% of patients. At M3 the median relative total weight loss (%TWL) was 20.1% and the median BMI was 36.1 kg/m2. LSM assessed by VCTE and 2DSWE, as well as median CAP all decreased significantly from BL to M3 both in the overall cohort and among patients with MASH. There was a decrease from BL to M3 in median levels of ALT (34.0 U/L to 31 U/L; p = 0.025), gamma glutamyl transferase (BL: 30.0 to 21.0 U/L; p < 0.001) and MASLD fibrosis score (BL: - 0.97 to - 1.74; p < 0.001). Decreasing LSM and CAP, as well as liver injury markers suggest an improvement of MASLD/MASH as early as 3 months after MBS.

Functional outcome after interdisciplinary, acute rehabilitation in COVID-19 patients: a retrospective study

BACKGROUND

Survivors of severe COVID-19 often exhibit a variety of sequelae including loss of mobility and ADL (activities of daily living) capacity. Acute rehabilitation (AR) is an interdisciplinary rehabilitation intervention applied early while still in a hospital setting. The goal of AR is to improve functional limitations and to increase functional independence at discharge. It is established in the treatment of patients with other severe diseases such as sepsis, polytrauma, or stroke. Data concerning AR in COVID-19 are sparse.

AIM

To evaluate the changes in physical function during AR in patients after severe COVID-19.

METHODS

This monocentric, retrospective observational study examined the functional outcomes of a sample of COVID-19-patients who received interdisciplinary AR at a university hospital. Inclusion criteria were a positive SARS-CoV-2 test in 05/2020-01/2022 and transfer to AR after intensive care treatment. 87 patients were elegible for evaluation, 3 of whom were excluded because of death during AR. Data were extracted from the hospital information system. In a pre-post analysis, mobility (Charité Mobility Index), ADL (Barthel Index), and oxygen demand were assessed. In addition, discharge location after AR, factors associated with AR unit length of stay, and functional improvements were analyzed.

RESULTS

Data of 84 patients were analyzed. Mobility increased significantly from a median of 4 [1.25-6] CHARMI points at admission to a median of 9 [8.25-9] at discharge (p < 0.001). ADL increased significantly from a median of 52.5 [35.0-68.75] Barthel Index points at admission to a median of 92.5 [85-95] at discharge (p < 0.001). Oxygen demand decreased from 80.7 to 30.5% of patients. The majority (55.9%) of patients were discharged home, while 36.9% received direct follow-up rehabilitation. Older age correlated significantly with lower scores on the discharge assessment for mobility (Spearman's ϱ = -0.285, p = 0.009) and ADL (Spearman's ϱ = -0.297, p = 0.006).

CONCLUSION

Acute rehabilitation is a viable option for COVID-19 patients with severe functional deficits after ICU treatment to achieve functional progress in mobility and ADL, reduce oxygen requirements and enable follow-up rehabilitation. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION FOR PROSPECTIVELY REGISTERED TRIALS: Trial registration number: DRKS00025239. Date of registration: 08 Sep 2021.

Immunopathogenesis of Primary Biliary Cholangitis, Primary Sclerosing Cholangitis and Autoimmune Hepatitis: Themes and Concepts

Autoimmune liver diseases include primary biliary cholangitis, primary sclerosing cholangitis, and autoimmune hepatitis, a family of chronic immune-mediated disorders that target hepatocytes and cholangiocytes. Treatments remain nonspecific, variably effective, and noncurative, and the need for liver transplantation is disproportionate to their rarity. Development of effective therapies requires better knowledge of pathogenic mechanisms, including the roles of genetic risk, and how the environment and gut dysbiosis cause immune cell dysfunction and aberrant bile acid signaling. This review summarizes key etiologic and pathogenic concepts and themes relevant for clinical practice and how such learning can guide the development of new therapies for people living with autoimmune liver diseases.

The Impact of COVID-19 during Pregnancy on Maternal Hemodynamic Function, Angiogenic Markers and Neonatal Outcome

Infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in pregnancy are associated with the development of preeclampsia and fetal growth restriction (FGR). Recently, preeclampsia was linked to impaired maternal hemodynamic function. This retrospective study evaluated singleton pregnancies with COVID-19 during pregnancy and healthy pregnant controls matched for gestational age from November 2020 to March 2022. Non-invasive assessment of maternal hemodynamics by continuous wave Doppler ultrasound measurements (USCOM-1A® Monitor) and oscillometric arterial stiffness (Arteriograph) was performed. Overall, 69 pregnant women were included-23 women after COVID-19 during pregnancy and 46 healthy controls. While two women (8.7%) were admitted to the hospital due to COVID-19-related symptoms, none required intensive care unit admission or non-invasive/invasive ventilation. There were no statistically significant differences in the majority of hemodynamic parameters between the two cohorts. The prevalence of FGR was significantly higher in the COVID-19 during pregnancy group (9.5% vs. healthy controls: 0.0%; p = 0.036), especially in nulliparous women. No difference in angiogenic markers and neonatal outcomes were observed between pregnant women after COVID-19 and healthy controls. In conclusion, no significant differences in hemodynamic parameters or neonatal outcome were observed in women with COVID-19 during pregnancy. However, an increased prevalence of FGR could be described.

Intrahepatic Cholestasis of Pregnancy during COVID-19 Pandemic

Background and Objectives: Intrahepatic cholestasis of pregnancy (ICP) stands as one of the most prevalent concerns in maternal-fetal medicine, presenting a significant risk to fetal health and often associated with liver dysfunction. Concurrently, the coronavirus-19 (COVID-19) infection can lead to hepatic cell injury through both direct and indirect pathways. Hypothetically, these two conditions may coincide, influencing each other. This study aimed to comparatively assess the incidence and severity of ICP before and during the COVID-19 pandemic. Methods: A retrospective cohort study was conducted, comparing the incidence and severity of ICP between January 2018 and February 2020 (pre-COVID-19 period) and March 2020 to March 2022 (COVID-19 period) across two hospitals, encompassing 7799 deliveries. The diagnosis of ICP was established using the ICD-10 code and defined as total bile acids (BA) levels ≥ 10 μmol/L. Statistical analysis included descriptive statistics, Chi-square and Mann-Whitney U tests, as well as multiple or logistic regression analysis. Results: A total of 226 cases of ICP were identified. The incidence of mild cholestasis (BA < 40 μmol/L) was lower during the pandemic compared to before (3% before versus 2%, p < 0.05), while the incidence of moderate and severe ICP remained unchanged (0.6% before vs. 0.4%, p = 0.2). Overall, the total incidence of ICP was lower during the pandemic (3.6% before versus 2.4%, p = 0.01). No significant differences were observed in severity (as defined by BA and liver function test levels), rates of caesarean section, or neonatal birth weights. Conclusions: During the COVID-19 pandemic, the total incidence of ICP appeared to be lower. However, this reduction was primarily observed in cases of mild ICP, potentially indicating challenges in detection or reduced access to medical services during this period. The incidence of moderate and severe ICP remained unchanged, suggesting that these forms of the condition were unaffected by the pandemic's circumstances.

Incidence of Secondary Sclerosing Cholangitis in Hospitalized Long COVID-19 Patients: A Retrospective Single Center Study

BACKGROUND

SARS-CoV-2 infection and associated COVID-19 disease can lead to critical illness with a risk of developing a multiple organ failure. Subsequently, this may lead to various pathological sequelae, such as secondary sclerosing cholangitis after surviving COVID-19 (SSC-COVID).

OBJECTIVE

The aim is to retrospectively analyze a cohort of hospitalized patients with first-wave (February 2020-June 2020) SARS-CoV-2 infection and persisting unclear cholangiopathy to determine the incidence of SSC-COVID and its risk factors.

RESULTS

A total of 249 patients were hospitalized at the university hospital in Tübingen, Germany, with SARS-CoV-2 infection during the first wave of the pandemic. Of these, 35.3% (88/249) required intensive care treatment; 16.5% (41/249) of them died due to the complications of COVID-19; 30.8% (64/208) of surviving patients could be followed up und were retrospectively analyzed at our center. The incidence of confirmed SSC-COVID was 7.8% (5/64). All SSC-COVID patients had an ICU stay >20 days, for invasive ventilation, positioning treatment, vasopressor treatment, but possible risk factors for SSC were not significant due to the small number of patients.

CONCLUSIONS

SSC-COVID is an emerging disease in post-COVID patients with a high incidence in our single-center cohort. SSC-COVID should be considered as a differential diagnosis, if unclear cholangiopathy or cholestasis persists after SARS-CoV-2 infection.

Arbidol attenuates liver fibrosis and activation of hepatic stellate cells by blocking TGF-β1 signaling

Chronic liver diseases (CLD) impact over 800 million people globally, causing about 2 million deaths annually. Arbidol (ARB), an indole-derivative used to treat influenza virus infection, was extensively used during COVID-19 pandemic in China. In recent years, studies have shown that ARB, compared to other antiviral drugs, exhibits greater liver-protective efficacy, indicating a potential hepatoprotective effect beyond its antiviral activity. However, the mechanism remains unclear. In this study, we investigated the impact of ARB on liver injury/fibrosis in bile duct ligated (BDL) mice and its effect on spontaneous and transforming growth factor β1 (TGF-β1)-induced activation of primary cultured hepatic stellate cells (HSCs). Oral administration of ARB significantly ameliorated BDL-induced liver injury/fibrosis as reflected by decreased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), reduced collagen deposition, and diminished mRNA expression of fibrosis markers. ARB notably inhibited spontaneous and TGF-β1-induced activation of primary cultured HSCs. Moreover, ARB also drastically attenuated mRNA expression levels of platelet-derived growth factor receptor (Pdgfr), transforming growth factor-beta receptor (Tgfbr) 1, Tgfbr2, matrix metalloproteinase (Mmp)-2, and Mmp-9 in activated HSCs. We further demonstrate that ARB mitigated Smad2/3 phosphorylation in both TGF-β1 treated HSCs and BDL mice. These data together demonstrate that the therapeutic efficacy of ARB on liver fibrosis is independent of its antiviral activity and likely is achieved by blocking TGF-β1 signaling-mediated HSC activation.

Phenotypes of Primary Sclerosing Cholangitis and Differential Diagnosis

Primary sclerosing cholangitis is a heterogenous immune-mediated disorder characterized by chronic inflammation and stricturing of the bile ducts. Though the driving pathophysiologic mechanisms remain elusive, there are several observed clinical phenotypes of the disease. The distribution of bile duct involvement, presence of concomitant inflammatory bowel disease, significant infiltration of IgG4-positive plasma cells, and overlapping features with other autoimmune disease has significant implications for prognosis and treatment. As there remains no pathognomonic finding for primary sclerosing cholangitis, a broad differential diagnosis and extensive evaluation of other underlying causes is critical to appropriate management.

Ketamine restriction correlates with reduced cholestatic liver injury and improved outcomes in critically ill patients with burn injury

Background & Aims

Ketamine-associated cholestatic liver injury is reported in patients with severe burn injury, but its association with patient outcome is unclear. We investigated the relationship between ketamine exposure, cholestatic liver injury, and outcome of critically ill patients with burn injury.

Methods

In a retrospective study, patients with severe burn injury were analysed across two periods: unrestricted ketamine prescription (ketamine-liberal) and capped ketamine dosage (ketamine-restricted). The primary endpoint was cholestatic liver injury, and the secondary endpoint was 3-month mortality. Binary logistic regression models and the revised electronic causality assessment method were used to measure the strength of associations and causality assessment, respectively.

Results

Of 279 patients (median age 51 [IQR 31-67] years; 63.1% men; burned surface area 28.5%, IQR 20-45%), 155 (56%) were in the ketamine-liberal group, and 124 (44%) were in the ketamine-restricted group, with comparable clinical characteristics, except for ketamine exposure (median doses 265.0 [IQR 0-8,021] mg and 20 [IQR 0-105] mg, respectively; p <0.001). A dose- and time-dependent relationship was observed between ketamine exposure and cholestatic liver injury. Ketamine restriction was associated with a reduced risk of cholestatic liver injury (adjusted odds ratio 0.16, 95% CI 0.04-0.50; p = 0.003) and with a higher probability of 3-month survival (p = 0.035). The revised electronic causality assessment method indicated that ketamine was probably and possibly the cause of cholestatic liver injury for 14 and 10 patients, respectively. Cholangitis was not observed in the ketamine-restricted group. In propensity-matched patients, the risk of 3-month mortality was higher (adjusted odds ratio 9.92, 95% CI 2.76-39.05; p = 0.001) in patients with cholestatic liver injury and ketamine exposure ≥10,000 mg. Other sedative drugs were not associated with liver and patient outcome.

Conclusions

In this cohort, ketamine restriction was associated with less cholestatic liver injury and reduced 3-month mortality.

Impact and implications

In a cohort of 279 critically ill patients with burn injury, ketamine was associated with a risk of liver bile duct toxicity. The risk was found to be dependent on both the dosage and duration of ketamine use. A restriction policy of ketamine prescription was associated with a risk reduction of liver injury and 3-month mortality. These findings have implications for the analgesia and sedation of critically ill patients with ketamine, with higher doses raising safety concerns.

Molecular mechanisms underlying SARS-CoV-2 hepatotropism and liver damage

In coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) primarily targets the respiratory system, but evidence suggests extrapulmonary organ involvement, notably in the liver. Viral RNA has been detected in hepatic tissues, and in situ hybridization revealed virions in blood vessels and endothelial cells. Electron microscopy confirmed viral particles in hepatocytes, emphasizing the need for understanding hepatotropism and direct cytopathic effects in COVID-19-related liver injury. Various factors contribute to liver injury, including direct cytotoxicity, vascular changes, inflammatory responses, immune reactions from COVID-19 and vaccinations, and drug-induced liver injury. Although a typical hepatitis presentation is not widely documented, elevated liver biochemical markers are common in hospitalized COVID-19 patients, primarily showing a hepatocellular pattern of elevation. Long-term studies suggest progressive cholestasis may affect 20% of patients with chronic liver disease post-SARS-CoV-2 infection. The molecular mechanisms underlying SARS-CoV-2 infection in the liver and the resulting liver damage are complex. This "Editorial" highlights the expression of the Angiotensin-converting enzyme-2 receptor in liver cells, the role of inflammatory responses, the impact of hypoxia, the involvement of the liver's vascular system, the infection of bile duct epithelial cells, the activation of hepatic stellate cells, and the contribution of monocyte-derived macrophages. It also mentions that pre-existing liver conditions can worsen the outcomes of COVID-19. Understanding the interaction of SARS-CoV-2 with the liver is still evolving, and further research is required.

Liver transplantation for post-COVID-19 cholangiopathy: A case series

BACKGROUND

Post-COVID-19 cholangiopathy is an emerging cholestatic liver disease observed in patients recovering from severe COVID-19 infection. Its prognosis is poor, necessitating liver transplantation in some cases. This study aimed to investigate the outcomes of liver transplantation for post-COVID-19 cholangiopathy.

METHODS

Seven patients who underwent liver transplantation for post-COVID-19 cholangiopathy at three institutions between 2020 and 2022 were included in this retrospective multi-center case series.

RESULTS

At the time of initial COVID-19 infection, all patients developed acute respiratory distress syndrome, and six patients (86%) required ICU admission. Median time intervals from the initial COVID-19 diagnosis to the diagnosis of post-COVID-19 cholangiopathy and liver transplantation were 4 and 12 months, respectively. Four patients underwent living donor liver transplantation, and three patients underwent deceased donor liver transplantation. The median MELD score was 22 (range, 10-38). No significant intraoperative complications were observed. The median ICU and hospital stays were 2.5 and 12.5 days, respectively. One patient died due to respiratory failure 5 months after liver transplantation. Currently, the patient and graft survival rate is 86% at a median follow-up of 11 months.

CONCLUSIONS

Liver transplantation is a viable option for patients with post-COVID-19 cholangiopathy with acceptable outcome. Timely identification of this disease and appropriate management, including evaluation for liver transplantation, are essential.

COVID-19 and the Liver: A Complex and Evolving Picture

Although the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primarily attacks the respiratory system, other organs, such as the liver, are also affected. In this overview, the effects of SARS-CoV-2 infection on the liver in both healthy people and in those with pre-existing liver disease are documented; the relationship between coronavirus disease 19 (COVID-19) vaccination and liver injury is examined; the mechanism of SARS-CoV-2-associated liver injury is explored; and the long-term consequences of COVID-19 are delineated, both in people with and without pre-existing liver disease.

Gastrointestinal hospitalization during COVID-19 pandemic in the United States: Analysis of a nationwide inpatient sample

BACKGROUND AND AIM

We aim to systematically investigate gastrointestinal (GI) hospitalizations in the United States during the early phase of the COVID-19 pandemic on a national level and the consequence that may inform practice and policies.

METHODS

A retrospective cross-sectional analysis of adult hospitalizations with GI-related diagnoses or procedures in the United States in 2020 was used, with hospitalizations from 2016 to 2019 used for contextual information.

RESULTS

Hospitalizations with principal and secondary GI diagnoses decreased by 13.3% and 8.2% from 2019 to 2020, respectively. Most GI diagnoses decreased in 2020, with a few exceptions including alcoholic liver disease (increased by 7.8% as a principal diagnosis) and acute liver failure (increased by 11.6% as a secondary diagnosis). The mortality rate of hospitalizations with GI disease increased in 2020 compared with 2019 (for principal diagnosis: adjusted odds ratio 1.08, 95% confidence interval 1.03-1.13, P = 0.001; for secondary diagnosis: adjusted odds ratio 1.10, 95% confidence interval 1.07-1.13, P < 0.001). Most GI procedures decreased except for a notable 8.3% increase in gastrostomy. The per-GI-hospitalization rate of procedures increased for hospitalizations with a principal GI diagnosis (56.4% vs 55.6%, P = 0.003) or unchanged for hospitalizations with secondary GI diagnoses (18.3% vs 18.2%, P = 0.512).

CONCLUSION

The COVID-19 pandemic resulted in a decrease in the volume of GI hospitalizations and procedures in 2020, but there was an increase in the mortality rate and some specific diagnoses including alcoholic liver disease and acute liver failure. These findings will likely enlighten future research and healthcare resource allocation for GI diseases.

Clinical and Histopathological Discoveries in Patients with Hepatic Injury and Cholangiopathy Who Have Died of COVID-19: Insights and Opportunities for Intervention

The COVID-19 pandemic has had a profound impact on global health, necessitating a comprehensive understanding of its diverse manifestations. Cholangiopathy, a condition characterized by biliary dysfunction, has emerged as a significant complication in COVID-19 patients. In this review, we report the epidemiology of COVID-19, describe the hepatotropism of SARS-CoV-2, and present the histopathology of acute liver injury (ALI) in COVID-19. Additionally, we explore the relationship between pre-existing chronic liver disease and COVID-19, shedding light on the increased susceptibility of these individuals to develop cholangiopathy. Through an in-depth analysis of cholangiopathy in COVID-19 patients, we elucidate its clinical manifestations, diagnostic criteria, and underlying pathogenesis involving inflammation, immune dysregulation, and vascular changes. Furthermore, we provide a summary of studies investigating post-COVID-19 cholangiopathy, highlighting the long-term effects and potential management strategies for this condition, and discussing opportunities for intervention, including therapeutic targets, diagnostic advancements, supportive care, and future research needs.

Post-COVID-19 cholangiopathy: Systematic review

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on global health, primarily characterized by severe respiratory illness. However, emerging evidence suggests that COVID-19 can also lead to secondary sclerosing cholangitis (SC), referred to as post-COVID-19 cholangiopathy.

AIM

To synthesize currently reported cases to assess the current state of knowledge on post-COVID-19 cholangiopathy.

METHODS

Medical Subject Headings and Health Sciences Descriptors were used to retrieve relevant studies, which were combined using Boolean operators. Searches were conducted on electronic databases including Scopus, Web of Science, and MEDLINE (PubMed). Studies published in English, Spanish, or Portuguese were included, with no restrictions on the publication date. Additionally, the reference lists of retrieved studies were manually searched. Simple descriptive analyses were used to summarize the results. Then the data were extracted and assessed based on Reference Citation Analysis (https://www.referencecitationanalysis.com/).

RESULTS

The initial search yielded a total of 192 articles. After screening, 85 articles were excluded due to duplication, leaving 107 articles for further review. Of these, 63 full-length articles met the inclusion criteria and were included in the analyses. Most of the patients were male and exhibited elevated liver function tests (93.8%). Magnetic resonance imaging revealed duct thickening with contrast enhancement (47.7%), as well as beading of the intrahepatic ducts (45.7%) with peribiliary contrast enhancement on diffusion (28.7%). Liver biopsy results confirmed SC in most cases (74.4%). Sixteen patients underwent liver transplantation, with three experiencing successful outcomes.

CONCLUSION

Post-COVID-19 cholangiopathy is a serious condition that is expected to become increasingly concerning in the coming years, particularly considering long COVID syndromes. Although liver transplantation has been proposed as a potential treatment option, more research is necessary to establish its efficacy and explore other potential treatments.

Liver Involvement during SARS-CoV-2 Infection Is Associated with a Worse Respiratory Outcome in COVID-19 Patients

Coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may be complicated by life-threatening interstitial pneumonia. SARS-CoV-2 infection may also damage several tissues and/or organs beyond the lungs, including the liver. However, controversy still exists as to whether SARS-CoV-2-induced liver alterations can have an impact on the outcome of COVID-19. The aim of this study was therefore to assess whether SARS-CoV-2-infected patients with liver abnormalities at the time of hospital referral had a worse outcome with respect to patients with no liver biochemistry alterations. To this end, the medical records of 123 patients admitted to our COVID center between the end of 2020 and spring 2021 were retrospectively reviewed. Patients were divided into two groups: those with normal liver biochemistries (group 1, 77 patients) and those with altered liver function tests (group 2, 46 patients). Serum levels of aminotransferases (AST and ALT) and bile duct cell injury markers (γ-GT and ALP) were used to dichotomize patients. A higher percentage of patients with liver enzyme alterations were found to develop COVID-19 pneumonia with respect to group 1 patients (74% vs. 65%); moreover, they needed more days of respiratory support and, more importantly, more intensive administration of supplemental oxygen. A statistically significant correlation was also found between aminotransferase levels and duration of respiratory support. The mortality rate was not superior in group 2 vs. group 1 patients. In conclusion, liver abnormalities on admission predisposed COVID-19 patients to development of more severe interstitial pneumonia, because of a longer requirement for supplemental oxygen and a more intensive respiratory support, indicative of a worse disease evolution in these patients.

The Many Faces of Primary Sclerosing Cholangitis: Controversy Abounds

Primary sclerosing cholangitis (PSC) is notoriously challenging to manage given its heterogeneity with regard to diagnosis, management, and progression. The lack of disease-modifying therapy and variable rate of onset of cirrhosis, portal hypertension-related decompensating events, jaundice, pruritus, biliary complications, and need for liver transplantation is deeply unsettling to clinicians and patients alike. Recent updated practice guidance by the American Association for the Study of Liver Diseases and the European Association for the Study of the Liver endeavored to highlight some of these challenges. However, these references only briefly address clinical dilemmas that providers face on a daily basis. This review aims to further discuss these controversial topics, including providing insight into the utility of ursodeoxycolic acid, the significance of alkaline phosphatase normalization, when to consider PSC variants and mimickers, and the implications of continuous hepatobiliary malignancy screening. In particular, there has been a growing body of literature raising concern about repeat exposure to gadolinium-containing contrast. Patients with PSC are potentially at risk for large lifetime exposure to gadolinium related to frequent magnetic resonance imaging scans and whether this carries any negative long-term adverse effects remains unknown.

Systemic Disease and the Liver-Part 1: Systemic Lupus Erythematosus, Celiac Disease, Rheumatoid Arthritis, and COVID-19

The development of liver dysfunction in patients having various systemic diseases is common and has a broad differential diagnosis, at times being the initial manifestation of the disorder. Liver injury associated with systemic lupus erythematosus is heterogeneous and may present with nonspecific histology. Differentiating autoimmune hepatitis from lupus hepatitis is challenging on histologic grounds alone. Other systemic diseases that may present mostly with nonspecific findings are rheumatoid arthritis and celiac disease. More recently COVID-19 cholangiopathy and secondary sclerosing cholangitis have become increasingly recognized as distinct liver conditions. Many patients may also have intrinsic liver disease or may develop drug-induced liver injury from the treatment of the systemic disease. Timely identification of the cause of the liver dysfunction is essential and liver biopsy may help the clinician in diagnosis and management.

The future of hepatology

The field of hepatology has made impressive progress over its ~75 years of existence. Advances in understanding liver function and its dysregulation in disease, genetic determinants of disease, antiviral therapy, and transplantation have transformed the lives of patients. However, there are still significant challenges that require ongoing creativity and discipline, particularly with the emergence of fatty liver diseases, as well as managing autoimmune disease, cancer, and liver disease in children. Diagnostic advances are urgently needed to accelerate risk stratification and efficient testing of new agents with greater precision in enriched populations. Integrated, holistic care models should be extended beyond liver cancer to diseases like NAFLD with systemic manifestations or extrahepatic comorbidities such as cardiovascular disease, diabetes, addiction, and depressive disorders. To meet the growing burden of asymptomatic liver disease, the workforce will need to be expanded by incorporating more advanced practice providers and educating other specialists. The training of future hepatologists will benefit from incorporating emerging skills in data management, artificial intelligence, and precision medicine. Continued investment in basic and translational science is crucial for further progress. The challenges ahead are significant, but with collective effort, the field of hepatology will continue to make progress and overcome obstacles.

Targeting Inflammasome Activation in Viral Infection: A Therapeutic Solution?

Inflammasome activation is exclusively involved in sensing activation of innate immunity and inflammatory response during viral infection. Accumulating evidence suggests that the manipulation of inflammasome assembly or its interaction with viral proteins are critical factors in viral pathogenesis. Results from pilot clinical trials show encouraging results of NLRP3 inflammasome suppression in reducing mortality and morbidity in SARS-CoV-2-infected patients. In this article, we summarize the up-to-date understanding of inflammasomes, including NLRP3, AIM2, NLRP1, NLRP6, and NLRC4 in various viral infections, with particular focus on RNA viruses such as SARS-CoV-2, HIV, IAV, and Zika virus and DNA viruses such as herpes simplex virus 1. We also discuss the current achievement of the mechanisms involved in viral infection-induced inflammatory response, host defense, and possible therapeutic solutions.

Role of microbiome in autoimmune liver diseases

The microbiome plays a crucial role in integrating environmental influences into host physiology, potentially linking it to autoimmune liver diseases, such as autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis. All autoimmune liver diseases are associated with reduced diversity of the gut microbiome and altered abundance of certain bacteria. However, the relationship between the microbiome and liver diseases is bidirectional and varies over the course of the disease. This makes it challenging to dissect whether such changes in the microbiome are initiating or driving factors in autoimmune liver diseases, secondary consequences of disease and/or pharmacological intervention, or alterations that modify the clinical course that patients experience. Potential mechanisms include the presence of pathobionts, disease-modifying microbial metabolites, and more nonspecific reduced gut barrier function, and it is highly likely that the effect of these change during the progression of the disease. Recurrent disease after liver transplantation is a major clinical challenge and a common denominator in these conditions, which could also represent a window to disease mechanisms of the gut-liver axis. Herein, we propose future research priorities, which should involve clinical trials, extensive molecular phenotyping at high resolution, and experimental studies in model systems. Overall, autoimmune liver diseases are characterized by an altered microbiome, and interventions targeting these changes hold promise for improving clinical care based on the emerging field of microbiota medicine.

Current Therapies for Cholestatic Diseases

Cholestasis is a condition characterized by decrease in bile flow due to progressive pathological states that lead to chronic cholestatic liver diseases which affect the biliary tree at the intrahepatic level and extrahepatic level. They induce complications such as cirrhosis, liver failure, malignancies, bone disease and nutritional deficiencies that merit close follow-up and specific interventions. Furthermore, as those conditions progress to liver cirrhosis, there will be an increase in mortality but also an important impact in quality of life and economic burden due to comorbidities related with liver failure. Therefore, it is important that clinicians understand the treatment options for cholestatic liver diseases. With a general view of therapeutic options and their molecular targets, this review addresses the pathophysiology of cholangiopathies. The objective is to provide clinicians with an overview of the safety and efficacy of the treatment of cholangiopathies based on the current evidence.

Unraveling the Molecular and Cellular Pathogenesis of COVID-19-Associated Liver Injury

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) continues to cause substantial morbidity and mortality. Most infections are mild; however, some patients experience severe and potentially fatal systemic inflammation, tissue damage, cytokine storm, and acute respiratory distress syndrome. Patients with chronic liver disease have been frequently affected, experiencing high morbidity and mortality. In addition, elevated liver enzymes may be a risk factor for disease progression, even in the absence of underlying liver disease. While the respiratory tract is a primary target of SARS-CoV-2, it has become evident that COVID-19 is a multisystemic infectious disease. The hepatobiliary system might be influenced during COVID-19 infection, ranging from a mild elevation of aminotransferases to the development of autoimmune hepatitis and secondary sclerosing cholangitis. Furthermore, the virus can promote existing chronic liver diseases to liver failure and activate the autoimmune liver disease. Whether the direct cytopathic effects of the virus, host reaction, hypoxia, drugs, vaccination, or all these risk factors cause liver injury has not been clarified to a large extent in COVID-19. This review article discussed the molecular and cellular mechanisms involved in the pathogenesis of SARS-CoV-2 virus-associated liver injury and highlighted the emerging role of liver sinusoidal epithelial cells (LSECs) in virus-related liver damage.

COVID-19 related biliary injury: A review of recent literature

Since its emergence in 2019, it has become apparent that coronavirus 2019 (COVID-19) infection can result in multi systemic involvement. In addition to pulmonary symptoms, hepatobiliary involvement has been widely reported. Extent of hepatic involvement ranges from minor elevation in liver function tests (LFTs) to significant hepatocellular or cholestatic injury. In majority of cases, resolution of hepatic injury or improvement in LFTs is noted as patients recover from COVID-19 infection. However, severe biliary tract injury progressing to liver failure has been reported in patients requiring prolonged intensive care unit stay or mechanical ventilation. Due to the timing of its presentation, this form of progressive cholestatic injury has been referred to as COVID-19 cholangiopathy or post-COVID-19 cholangiopathy, and can result in devastating consequences for patients. COVID-19 cholangiopathy is recognized by dramatic elevation in serum alkaline phosphatase and bilirubin and radiologic evidence of bile duct injury. Cholangiopathy in COVID-19 occurs weeks to months after the initial infection and during the recovery phase. Imaging findings and pathology often resemble bile duct injury associated with primary or secondary sclerosing cholangitis. Etiology of COVID-19 cholangiopathy is unclear. Several mechanisms have been proposed, including direct cholangiocyte injury, vascular compromise, and cytokine release syndromes. This review summarizes existing data on COVID-19 cholangiopathy, including reported cases in the literature, proposed pathophysiology, diagnostic testing, and long-term implications.

Liver and Biliary Tract Disease in Patients with Coronavirus disease-2019 Infection

Coronavirus disease-2019 (COVID-19) had become a global pandemic since March 2020. Although, the most common presentation is of pulmonary involvement, hepatic abnormalities can be encountered in up to 50% of infected individuals, which may be associated with disease severity, and the mechanism of liver injury is thought to be multifactorial. Guidelines for management in patients with chronic liver disease during COVID-19 era are being regularly updated. Patients with chronic liver disease and cirrhosis, including liver transplant candidates and liver transplant recipients are strongly recommended to receive SARS-CoV-2 vaccination because it can reduce rate of COVID-19 infection, COVID-19-related hospitalization, and mortality.

COVID-19-Associated Liver Injury

This review analyzes data regarding liver injury associated with COVID-19 infection. We discuss reported effects on the liver from both COVID-19 and COVID-19 treatment as well as pathophysiology, review the potential role of drug-induced liver injury as an etiology of COVID-19-associated liver injury, and touch on other reports of significant outcomes including COVID-19 cholangiopathy and autoimmune hepatitis. Finally, we review the implications of COVID-19 infection in liver transplant recipients.

Outcomes of COVID-19 among patients with liver disease

Coronavirus disease 2019 (COVID-19) is primarily a respiratory disease with multi-organ involvement, including impaired liver function. It has been noticed that a significant proportion of COVID-19 patients have liver dysfunction, especially those with a more severe disease course. The coronavirus causes direct damage to the liver using the angiotensin-converting enzyme 2, a cell-surface receptor for cellular entry, that is expressed in the liver. According to previous research, liver enzyme abnormalities were observed in a considerable proportion of COVID-19 patients, and elevated liver transaminases were found in about 20% of these patients, alkaline phosphatase in 6.1%, and gamma-glutamyl transferase in 21.1%. COVID-19 might trigger a deterioration of liver function in patients with pre-existing chronic liver diseases (CLDs) and also in those without previous liver disorders. The majority of COVID-19 patients who develop liver injury are men, the elderly, and those with a higher body mass index. Compared to the general population, COVID-19 is associated with significant morbidity and mortality in patients with liver disease (cirrhosis and liver transplantation recipients). However, some studies indicate that CLDs have a lesser role in determining patient progression towards higher disease severity.

Liver involvement in patients with COVID-19 infection: A comprehensive overview of diagnostic imaging features

During the first wave of the pandemic, coronavirus disease 2019 (COVID-19) infection has been considered mainly as a pulmonary infection. However, different clinical and radiological manifestations were observed over time, including involvement of abdominal organs. Nowadays, the liver is considered one of the main affected abdominal organs. Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs. After clinical assessment, radiology plays a key role in the evaluation of liver involvement. Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate liver involvement. US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection, in particular liver steatosis and portal-vein thrombosis. CT and MRI are used as second- and third-line techniques, respectively, considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization. This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage.

Profile of liver cholestatic biomarkers following prolonged ketamine administration in patients with COVID-19

BACKGROUND

To investigate the possible influence of prolonged ketamine (K) or esketamine (ESK) infusion on the profile of liver cholestatic biomarkers in patients with COVID-19 infection.

METHODS

A retrospective analysis was performed on 135 patients with COVID-19 related ARDS who received prolonged K or ESK infusion. They were compared to 15 COVID-19 ICU patients who did not receive K/ESK while being mechanically ventilated and 108 COVID-19 patients who did not receive mechanical ventilation nor K/ESK. The profile of the liver function tests was analysed in the groups.

RESULTS

Peak values of ALP, GGT and bilirubin were higher in the K/ESK group, but not for AST and ALT. Peak values of ALP were significantly higher among patients who underwent mechanical ventilation and who received K/ESK, compared with mechanically ventilated patients who did not receive K/ESK. There was a correlation between these peak values and the cumulative dose and duration of K/ESK therapy.

CONCLUSIONS

Based on the observations of biliary anomalies in chronic ketamine abusers, prolonged exposure to ketamine sedation during mechanical ventilation may also be involved, in addition to viral infection causing secondary sclerosing cholangitis. The safety of prolonged ketamine sedation on the biliary tract requires further investigations.

Multiorgan Failure and Omicron: A Suspected Case of Post-COVID-19 Cholangiopathy

Since the declaration of a global pandemic by the World Health Organization on March 11, 2020, coronavirus disease 2019 (COVID-19) has impacted millions worldwide. This complex disease process has been primarily associated with respiratory illness. As we continue to learn about COVID-19, there appears to be a growing spectrum of non-pulmonary manifestations. A major topic of interest is hepatic dysfunction related to COVID-19, specifically the growing number of cases involving acute liver failure in the setting of COVID-19. Here, we present a rare case of a patient with COVID-19 antibodies, negative inpatient COVID-19 testing, jaundice, and elusive multiorgan dysfunction.

SARS-CoV-2 Infection and Liver Disease: A Review of Pathogenesis and Outcomes

The impact of the coronavirus disease 2019 (COVID-19) pandemic has been immense, and it continues to have lasting repercussions. While the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus primarily infects the respiratory system, other organ systems are affected, including the liver. Scientific knowledge on the role of SARS-CoV-2 infection and liver injury has evolved rapidly, with recent data suggesting specific hepatotropism of SARS-CoV-2. Moreover, additional concerns have been raised in regard to long-term liver damage, related to emerging cases of post-COVID-19 cholangiopathy and chronic cholestasis. Great effort has also been focused on studying how specific subpopulations with chronic medical conditions might be disproportionately impacted by COVID-19. One such population includes individuals with chronic liver disease (CLD) and cirrhosis, with an expanding body of research indicating these patients being particularly susceptible to adverse outcomes. In this review, we provide an updated summary on the current pathogenesis and mechanism of liver injury in the setting of SARS-CoV-2 infection, the association between health outcomes and SARS-CoV-2 infection in patients with CLD, and the unique consequences of the COVID-19 pandemic on the routine care of patients with CLD.

COVID-19 and MAFLD/NAFLD: An updated review

The COVID-19 pandemic is ongoing and places a substantial burden on healthcare systems worldwide. As we further shed light on different disease characteristics, we identify more and more groups of people at higher risk of poor COVID-19 outcomes. Metabolic-associated fatty liver disease (MAFLD) (previously non-alcoholic fatty liver disease or NAFLD) is a common metabolic disorder characterized by fat accumulation and liver fibrosis. Given its close correlation with metabolic syndrome, an established risk factor for severe COVID-19, it is necessary to investigate its interplay with the novel coronavirus. In this study, we review the available data on COVID-19 prognosis, treatment and prevention options in patients with MAFLD, and the effect that the disease and the pandemic have on MAFLD care. Furthermore, we point out the gaps in the current literature to accentuate the work that needs to be done to improve MAFLD care during the pandemic and beyond.

Risk of New-Onset Liver Injuries Due to COVID-19 in Preexisting Hepatic Conditions-Review of the Literature

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacted the world and caused the 2019 coronavirus disease (COVID-19) pandemic. The clinical manifestations of the virus can vary from patient to patient, depending on their respective immune system and comorbidities. SARS-CoV-2 can affect patients through two mechanisms: directly by targeting specific receptors or by systemic mechanisms. We reviewed data in the latest literature in order to discuss and determine the risk of new-onset liver injuries due to COVID-19 in preexisting hepatic conditions. The particular expression of angiotensin-converting enzyme 2 (ACE2) receptors is an additional risk factor for patients with liver disease. COVID-19 causes more severe forms in patients with non-alcoholic fatty liver disease (NAFLD), increases the risk of cirrhosis decompensation, and doubles the mortality for these patients. The coinfection SARS-CoV-2-viral hepatitis B or C might have different outcomes depending on the stage of the liver disease. Furthermore, the immunosuppressant treatment administered for COVID-19 might reactivate the hepatic virus. The high affinity of SARS-CoV-2 spike proteins for cholangiocytes results in a particular type of secondary sclerosing cholangitis. The impact of COVID-19 infection on chronic liver disease patients is significant, especially in cirrhosis, influencing the prognosis and outcome of these patients.

Living with liver disease in the era of COVID-19-the impact of the epidemic and the threat to high-risk populations

The cardinal symptoms of severe acute respiratory syndrome coronavirus 2 infection as the pandemic began in 2020 were cough, fever, and dyspnea, thus characterizing the virus as a predominantly pulmonary disease. While it is apparent that many patients presenting acutely to the hospital with coronavirus disease 2019 (COVID-19) infection have complaints of respiratory symptoms, other vital organs and systems are also being affected. In fact, almost half of COVID-19 hospitalized patients were found to have evidence of some degree of liver injury. Incidence and severity of liver injury in patients with underlying liver disease were even greater. According to the Centers of Disease Control and Prevention, from August 1, 2020 to May 31, 2022 there have been a total of 4745738 COVID-19 hospital admissions. Considering the gravity of the COVID-19 pandemic and the incidence of liver injury in COVID-19 patients, it is imperative that we as clinicians understand the effects of the virus on the liver and conversely, the effect of underlying hepatobiliary conditions on the severity of the viral course itself. In this article, we review the spectrum of novel studies regarding COVID-19 induced liver injury, compiling data on the effects of the virus in various age and high-risk groups, especially those with preexisting liver disease, in order to obtain a comprehensive understanding of this disease process. We also provide an update of the impact of the new Omicron variant and the changing nature of COVID-19 pathogenesis.

COVID-19 associated liver injury: A general review with special consideration of pregnancy and obstetric outcomes

Liver injury is an increasingly recognized extra-pulmonary manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Coronavirus disease 2019 (COVID-19) associated liver injury (COVALI) is a clinical syndrome encompassing all patients with biochemical liver injury identified in the setting of SARS-CoV-2 infection. Despite profound clinical implications, its pathophysiology is poorly understood. Unfortunately, most information on COVALI is derived from the general population and may not be applicable to individuals under-represented in research, including pregnant individuals. This manuscript reviews: Clinical features of COVALI, leading theories of COVALI, and existing literature on COVALI during pregnancy, a topic not widely explored in the literature. Ultimately, we synthesized data from the general and perinatal populations that demonstrates COVALI to be a hepatocellular transaminitis that is likely induced by systemic inflammation and that is strongly associated with disease severity and poorer clinical outcome, and offered perspective on approaching transaminitis in the potentially COVID-19 positive patient in the obstetric setting.

A single-nucleus and spatial transcriptomic atlas of the COVID-19 liver reveals topological, functional, and regenerative organ disruption in patients

The molecular underpinnings of organ dysfunction in acute COVID-19 and its potential long-term sequelae are under intense investigation. To shed light on these in the context of liver function, we performed single-nucleus RNA-seq and spatial transcriptomic profiling of livers from 17 COVID-19 decedents. We identified hepatocytes positive for SARS-CoV-2 RNA with an expression phenotype resembling infected lung epithelial cells. Integrated analysis and comparisons with healthy controls revealed extensive changes in the cellular composition and expression states in COVID-19 liver, reflecting hepatocellular injury, ductular reaction, pathologic vascular expansion, and fibrogenesis. We also observed Kupffer cell proliferation and erythrocyte progenitors for the first time in a human liver single-cell atlas, resembling similar responses in liver injury in mice and in sepsis, respectively. Despite the absence of a clinical acute liver injury phenotype, endothelial cell composition was dramatically impacted in COVID-19, concomitantly with extensive alterations and profibrogenic activation of reactive cholangiocytes and mesenchymal cells. Our atlas provides novel insights into liver physiology and pathology in COVID-19 and forms a foundational resource for its investigation and understanding.

A single-nucleus and spatial transcriptomic atlas of the COVID-19 liver reveals topological, functional, and regenerative organ disruption in patients

The molecular underpinnings of organ dysfunction in acute COVID-19 and its potential long-term sequelae are under intense investigation. To shed light on these in the context of liver function, we performed single-nucleus RNA-seq and spatial transcriptomic profiling of livers from 17 COVID-19 decedents. We identified hepatocytes positive for SARS-CoV-2 RNA with an expression phenotype resembling infected lung epithelial cells. Integrated analysis and comparisons with healthy controls revealed extensive changes in the cellular composition and expression states in COVID-19 liver, reflecting hepatocellular injury, ductular reaction, pathologic vascular expansion, and fibrogenesis. We also observed Kupffer cell proliferation and erythrocyte progenitors for the first time in a human liver single-cell atlas, resembling similar responses in liver injury in mice and in sepsis, respectively. Despite the absence of a clinical acute liver injury phenotype, endothelial cell composition was dramatically impacted in COVID-19, concomitantly with extensive alterations and profibrogenic activation of reactive cholangiocytes and mesenchymal cells. Our atlas provides novel insights into liver physiology and pathology in COVID-19 and forms a foundational resource for its investigation and understanding.

Impact of COVID-19 on the liver and on the care of patients with chronic liver disease, hepatobiliary cancer, and liver transplantation: An updated EASL position paper

The COVID-19 pandemic has presented a serious challenge to the hepatology community, particularly healthcare professionals and patients. While the rapid development of safe and effective vaccines and treatments has improved the clinical landscape, the emergence of the omicron variant has presented new challenges. Thus, it is timely that the European Association for the Study of the Liver provides a summary of the latest data on the impact of COVID-19 on the liver and issues guidance on the care of patients with chronic liver disease, hepatobiliary cancer, and previous liver transplantation, as the world continues to deal with the consequences of the COVID-19 pandemic.

COVID-19-associated liver injury: Clinical characteristics, pathophysiological mechanisms and treatment management

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a global epidemic and poses a major threat to public health. In addition to COVID-19 manifesting as a respiratory disease, patients with severe disease also have complications in extrapulmonary organs, including liver damage. Abnormal liver function is relatively common in COVID-19 patients; its clinical manifestations can range from an asymptomatic elevation of liver enzymes to decompensated hepatic function, and liver injury is more prevalent in severe and critical patients. Liver injury in COVID-19 patients is a comprehensive effect mediated by multiple factors, including liver damage directly caused by SARS-CoV-2, drug-induced liver damage, hypoxia reperfusion dysfunction, immune stress and inflammatory factor storms. Patients with chronic liver disease (especially alcohol-related liver disease, nonalcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma) are at increased risk of severe disease and death after infection with SARS-CoV-2, and COVID-19 aggravates liver damage in patients with chronic liver disease. This article reviews the latest SARS-CoV-2 reports, focusing on the liver damage caused by COVID-19 and the underlying mechanism, and expounds on the risk, treatment and vaccine safety of SARS-CoV-2 in patients with chronic liver disease and liver transplantation.

The impact of COVID-19 on liver transplantation programs in Austria

BACKGROUND

Coronavirus disease of 2019 (COVID-19) has affected liver disease management. The impact of the COVID-19 pandemic on the Austrian orthotopic liver transplantation (OLT) programs, however, has not been systematically investigated.

METHODS

All patients listed for OLT in Austria during 2020-2021 were studied. Data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing, vaccinations, infections, mortality and the overall number of OLTs (vs. pre-COVID-19: 2015-2019) were analyzed.

RESULTS

Overall, 490 patients (median age: 58.0 years, 70.4% men, hepatocellular carcinoma: 27.3%) were listed for OLT in Austria in 2020-2021. Alcohol-related cirrhosis (35.3%), cholestatic (16.7%) and viral liver disease (13.9%) were the main etiologies. Of the patients 61.2% underwent OLT and 8.8% died while on the waiting list. The number of OLTs performed during COVID-19 (2020: n = 150; 2021: n = 150) remained unchanged compared to pre-COVID-19 (median: n = 152). Among waiting list patients, 7.7% (n = 31/401) were diagnosed with COVID-19 and 7 (22.6%) of these patients died. By the end of 2021, 45.1% (n = 176/390; 82.8% mRNA vaccinations) and 28.8% (105/365) of patients received 2 and 3 SARS-CoV‑2 vaccinations, respectively. After two SARS-CoV‑2 vaccinations, antibodies more often remained undetectable in patients vaccinated post-OLT (25.6% vs. 6.5% in patients vaccinated pre-OLT; p = 0.034). Patients with three vaccinations after OLT had lower antibody titers than patients vaccinated pre-OLT (post-OLT: 513.5, IQR 44.4-2500.0 vs. pre-OLT: 2500.0, IQR 1462.0-2500.0 BAU/mL; p = 0.020).

CONCLUSION

The number of OLTs in Austria remained unchanged during COVID-19. SARS-CoV‑2 infections were rare but associated with high mortality in patients on the Austrian OLT waiting lists. SARS-CoV‑2 vaccination rates at the end of 2021 were suboptimal, while serological response was better in patients vaccinated pre-OLT vs. post-OLT.