Clinical Features of Patients Infected With Coronavirus Disease 2019 With Elevated Liver Biochemistries: A Multicenter, Retrospective Study

Procoagulant phenotype of virus-infected pericytes is associated with portal thrombosis and intrapulmonary vascular dilations in fatal COVID-19

BACKGROUND & AIMS

The underlying mechanisms and clinical impact of portal microthrombosis in severe COVID-19 are unknown. Intrapulmonary vascular dilation (IPVD)-related hypoxia has been described in severe liver diseases. We hypothesised that portal microthrombosis is associated with IPVD and fatal respiratory failure in COVID-19.

METHODS

Ninety-three patients who died from COVID-19 were analysed for portal microvascular damage (histology), IPVD (histology and chest-computed tomography, CT), and hypoxemia (arterial blood gas). Seventeen patients who died from COVID-19-unrelated pneumonia served as controls. Vascular lesions and microthrombi were phenotyped for endothelial (vWF) and pericyte (αSMA/PDGFR-β) markers, tissue factor (TF), viral spike protein and nucleoprotein (SP, NP), fibrinogen, and platelets (CD41a). Viral particles in vascular cells were assessed by transmission electron microscopy. Cultured pericytes were infected with SARS-CoV-2 to measure TF expression and tubulisation of human pulmonary microvascular endothelial cells was assessed upon vWF treatment.

RESULTS

IPVD was present in 16/66 patients with COVID-19, with available liver and lung histology, and was associated with younger age (62 vs. 78 years-old), longer illness (25 vs. 14 days), worsening hypoxemia (PaO2/FiO2 from 209 to 89), and an increased requirement for ventilatory support (63% vs. 22%) compared to COVID-19/Non-IPVD. IPVD, absent in controls, was confirmed by chest CT. COVID-19/IPVD liver histology showed portal microthrombosis in >82.5% of portal areas, with a thicker wall of αSMA/PDGFR-β+/SP+/NP+ pericytes compared with COVID-19/Non-IPVD. Thrombosed portal venules correlated with αSMA+ area, whereas infected SP+/NP+ pericytes expressed TF. SARS-CoV-2 viral particles were observed in portal pericytes. In vitro SARS-CoV-2 infection of pericytes upregulated TF and induced endothelial cells to overexpress vWF, which expanded human pulmonary microvascular endothelial cell tubules.

CONCLUSIONS

SARS-CoV-2 infection of liver pericytes elicits a local procoagulant response associated with extensive portal microthrombosis, IPVD and worsening respiratory failure in fatal COVID-19.

IMPACT AND IMPLICATIONS

Vascular involvement of the liver represents a serious complication of COVID-19 infection that must be considered in the work-up of patients with long-lasting and progressively worsening respiratory failure, as it may associate with the development of intrapulmonary vascular dilations. This clinical picture is associated with a procoagulant phenotype of portal venule pericytes, which is induced by SARS-CoV-2 infection of pericytes. Both observations provide a model that may apply, at least in part, to other vascular disorders of the liver, featuring obliterative portal venopathy, similarly characterised at the clinical level by development of hypoxemia and at the histological level by phlebosclerosis and reduced calibre of the portal vein branches in the absence of cirrhosis. Moreover, our findings shed light on an overlooked player in the pathophysiology of thrombosis, i.e. pericytes, which may present a novel therapeutic target.

Liver function abnormality on admission predicts long COVID syndrome in digestive system

Background

Clinical practice showed that many patients with SARS-CoV-2 infection presented with long COVID syndrome in digestive system. We sought to investigate the factor affecting the incidence of long COVID syndrome in digestive system.

Methods and results

Patients with SARS-CoV-2 infection diagnosed at two centers of Zhongshan Hospital and one center of Shanghai Pudong Hospital from March 01, 2022 to May 31, 2022 were enrolled, collected in the hospital database, and followed up until March 30, 2023. The primary outcome of the study was the occurrence of post-acute sequelae of COVID-19 in the digestive system (long COVID syndrome). Modified Poisson regression was used to calculate the relative risk (RR). This cohort study included 494 patients with SARS-CoV-2 infection, 144 (29.1 %) patients developed liver function abnormality on admission. During the follow-up period, the primary study outcome occurred in 30 (20.8 %) of the group presenting with liver function abnormality on admission and in 20 (5.7 %) of the group without liver function abnormality on admission (adjusted, RR = 3.550, 95%CI: 2.099-6.006, P ≤ 0.001).

Conclusion

Our study suggests that patients with COVID-19 who experience liver function abnormality on admission have an increased risk of developing long COVID syndrome in the digestive system.

An Increase in Aspartate Aminotransferase Can Predict Worsening Disease Severity in Japanese Patients with COVID-19

BACKGROUND

The prognostic significance of liver dysfunction in COVID-19 patients remains unclear. In this study, we investigated the association between liver function test results and severe disease progression in COVID-19 patients.

METHODS

This retrospective study included consecutive Japanese COVID-19 patients admitted between February 2020 and July 2021. Predictive variables for severe disease progression were identified by multivariate logistic regression analysis. Severe disease-free survival was estimated with the Kaplan-Meier method and Cox regression analysis. Aspartate aminotransferase (AST) was divided into three grades: grade 1, AST < 30 U/L; grade 2, 30 U/L ≤ AST < 60 U/L; and grade 3, AST > 60 U/L.

RESULTS

Among 604 symptomatic patients, 141 (23.3%) developed severe disease at a median of 2 days postadmission. The median hospital stay was 10 days, and 43 patients (7.1%) died during hospitalization. Multivariate regression analysis revealed that hypertension, decreased lymphocyte count, and elevated LDH, CRP, and AST levels (grade 2 and grade 3 relative to grade 1) were the significant predictive variables. Severe disease-free survival time was significantly different between the different AST grades (hazard ratio (HR): grade 2 vs. grade 1, 4.07 (95% confidential interval (CI): 2.06-8.03); grade 3 vs. grade 1, 7.66 (95% CI: 3.89-15.1)).

CONCLUSIONS

The AST level at admission was an independent risk factor for severe disease in hospitalized Japanese patients with COVID-19.

COVID-19, Possible Hepatic Pathways and Alcohol Abuse-What Do We Know up to 2023?

The pandemic period due to coronavirus disease 2019 (COVID-19) revolutionized all possible areas of global health. Significant consequences were also related to diverse extrapulmonary manifestations of this pathology. The liver was found to be a relatively common organ, beyond the respiratory tract, affected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Multiple studies revealed the essential role of chronic liver disease (CLD) in the general outcome of coronavirus infection. Present concerns in this field are related to the direct hepatic consequences caused by COVID-19 and pre-existing liver disorders as risk factors for the severe course of the infection. Which mechanism has a key role in this phenomenon-previously existing hepatic disorder or acute liver failure due to SARS-CoV-2-is still not fully clarified. Alcoholic liver disease (ALD) constitutes another not fully elucidated context of coronavirus infection. Should the toxic effects of ethanol or already developed liver cirrhosis and its consequences be perceived as a causative or triggering factor of hepatic impairment in COVID-19 patients? In the face of these discrepancies, we decided to summarize the role of the liver in the whole picture of coronavirus infection, paying special attention to ALD and focusing on the pathological pathways related to COVID-19, ethanol toxicity and liver cirrhosis.

Liver dysfunction and clinical outcomes of unvaccinated COVID-19 patients with and without chronic hepatitis B

BACKGROUND

Liver dysfunction is common during coronavirus disease 2019 (COVID-19), while its clinical impact and association with chronic hepatitis B (CHB) remain uncertain. We aimed to investigate liver dysfunction in COVID-19 patients and its impacts on those with/without CHB.

METHODS

We conducted a retrospective cohort study of COVID-19 patients at National Taiwan University Hospital, stratified according to hepatitis B surface antigen (HBsAg) serostatus, with demographics, laboratory data, and hospitalization course reviewed, and clinical outcomes compared through multivariable analyses.

RESULTS

We enrolled 109 COVID-19 patients unvaccinated against SARS-CoV-2 by August 2021. The HBsAg-positive group (n = 34) had significantly higher alanine aminotransferase (ALT) (26 vs. 16 U/L, P = 0.034), platelet (224 vs. 183 k/μL, P = 0.010) and longer hospitalizations (17 vs. 13 days, P = 0.012) compared with HBsAg-negative group (n = 75), while percentages of hepatitis (2-fold ALT elevation), oxygen supplementation, ventilators usage, COVID-specific treatment, intensive care unit (ICU) admission and mortality were comparable. Older age (odds ratio [OR]: 1.04, 95 % confidence interval [CI]: 1.00-1.08, P = 0.032) and higher aspartate aminotransferase (AST) (OR: 1.08, 95 % CI: 1.004-1.16, P = 0.038) were associated with oxygen supplementation according to multivariable analyses. Higher AST predicted ICU admission (OR: 1.11, 95 % CI: 1.03-1.19, P = 0.008). Oxygen usage (OR: 5.64, 95 % CI: 1.67-19.09, P = 0.005) and shock (OR: 5.12, 95 % CI: 1.14-22.91, P = 0.033) were associated with liver dysfunction.

CONCLUSIONS

CHB patients had higher ALT levels and longer hospitalizations during COVID-19. Higher AST levels predict severe COVID-19 and ICU admission.

Effects of COVID-19 on the Liver and Mortality in Patients with SARS-CoV-2 Pneumonia Caused by Delta and Non-Delta Variants: An Analysis in a Single Centre

The aim of this study was to ascertain patient characteristics, outcomes, and liver injuries in patients infected with different SARS-CoV-2 variants. Data from consecutive adult patients with severe/critical COVID-19 admitted to our hospital during the peak month of the Delta wave were compared to the ancestral, Alpha, and Omicron waves. The dataset of 551 hospitalized patients was similar in the Delta/non-Delta waves. At admission and discharge, the median aminotransferase levels were normal or slightly increased. During the Delta wave (172 vs. 379 non-Delta patients), more patients died (OR 1.69, 95%CI 1.09-2.56) or had liver injury at discharge (alanine aminotransferase, ALT ≥ 2 ULN) (OR 1.97, 95%CI 1.08-3.54). In-hospital mortality was associated with age, lung injury, intensive care unit admission, number of and cardiovascular comorbidities, diabetes, chronic kidney disease, and all inflammatory biomarkers. Serious liver injury at admission (ALT ≥ 5 × ULN) was significantly associated with in-hospital mortality (OR = 7.9, 95%CI 2-28.9). At discharge, drug-induced liver injury (DILI) was found in patients treated with remdesivir, ALT ≥ 2 ULN (OR = 2.62, 95%CI 1.22-5.75). Treatment with dexamethasone, remdesivir, and immunomodulators showed improved survival, OR = 0.50 (95%CI 0.33-0.77). Regardless of the variant and treatment options, less than 2% of patients displayed serious liver injury, which was not found to be a death predictor in multivariable analysis.

COVID-19-associated liver injury: Adding fuel to the flame

COVID-19 is mainly characterized by respiratory disorders and progresses to multiple organ involvement in severe cases. With expansion of COVID-19 and SARS-CoV-2 research, correlative liver injury has been revealed. It is speculated that COVID-19 patients exhibited abnormal liver function, as previously observed in the SARS and MERS pandemics. Furthermore, patients with underlying diseases such as chronic liver disease are more susceptible to SARS-CoV-2 and indicate a poor prognosis accompanied by respiratory symptoms, systemic inflammation, or metabolic diseases. Therefore, COVID-19 has the potential to impair liver function, while individuals with preexisting liver disease suffer from much worse infected conditions. COVID-19 related liver injury may be owing to direct cytopathic effect, immune dysfunction, gut-liver axis interaction, and inappropriate medication use. However, discussions on these issues are infancy. Expanding research have revealed that angiotensin converting enzyme 2 (ACE2) expression mediated the combination of virus and target cells, iron metabolism participated in the virus life cycle and the fate of target cells, and amino acid metabolism regulated immune response in the host cells, which are all closely related to liver health. Further exploration holds great significance in elucidating the pathogenesis, facilitating drug development, and advancing clinical treatment of COVID-19-related liver injury. This article provides a review of the clinical and laboratory hepatic characteristics in COVID-19 patients, describes the etiology and impact of liver injury, and discusses potential pathophysiological mechanisms.

Association between acute liver injury & severity and mortality of COVID-19 patients: A systematic review and meta-analysis

Background

Acute liver injury (ALI), a complication often seen in COVID-19 patients, can lead to severe liver damage, multi-organ failure, acute vascular events, and can potentially escalate to patient mortality. Given this, we initiated a meta-analysis to investigate the correlation between ALI and adverse outcomes in COVID-19 patients.

Methods

We conducted an exhaustive search of databases, including Medline, Embase, PubMed Central, ScienceDirect, Google Scholar, and the Cochrane Library, from the November 2019 until January 2022. The quality of the included studies was evaluated using the Newcastle Ottawa (NO) scale. Our meta-analysis was carried out using a random-effects model and results were presented as pooled odds ratios (ORs) with their corresponding 95% confidence intervals (CIs).

Results

Our analysis incorporated 20 studies involving a total of 13,850 participants, predominantly from China and the United States. According to the NO scale, the majority of these studies were categorized as low-quality. Patients with ALI faced approximately 7 times higher odds of severe COVID-19 symptoms (pooled OR = 7.09; 95%CI: 4.97 to 10.12) and over 5 times higher odds of mortality (pooled OR = 5.50; 95%CI: 3.37 to 8.99) when compared to those without ALI.

Conclusion

Our findings affirm that ALI is a potent predictor of adverse outcomes, including severity and mortality, among COVID-19 patients. Recognizing and promptly addressing ALI in COVID-19 patients could be pivotal in improving prognosis and tailoring individualized patient management strategies. This underscores the need for clinicians to be vigilant about liver complications in the COVID-19 patients and integrate appropriate interventions in the treatment paradigm.

COVID-19 and Liver Disease: An Evolving Landscape

The COVID-19 pandemic has resulted in significant worldwide morbidity and mortality. In this review, we examine the intricate relationships between COVID-19 and liver diseases. While respiratory manifestations of COVID-19 are well known, its impact and consequences in patients with liver diseases remain an area of ongoing investigation. COVID-19 can induce liver injury through various mechanisms and is associated with higher mortality in individuals with preexisting chronic liver disease. Mortality increases with the severity of chronic liver disease and the level of care required. The outcomes in patients with autoimmune hepatitis remain unclear, whereas liver transplant recipients are more likely to experience symptomatic COVID-19 but have comparable outcomes to the general population. Despite suboptimal immunological response, COVID-19 vaccinations are safe and effective in liver disease, although cases of autoimmune hepatitis-like syndrome have been reported. In conclusion, COVID-19 has significant implications in liver diseases; early recognition and treatments are important for improving patient outcomes.

Predictors and Outcomes of Hospitalized COVID-19 Patients with Liver Injury

Objective

To determine incidence, predictors, and impact of liver injury among hospitalized COVID-19 patients.

Methods

This is a retrospective cohort study of hospitalized COVID-19 patients at the University of the Philippines-Philippine General Hospital. Liver injury (LI) was defined as ALT elevation above institutional cut-off (>50 u/L) and was classified as mild (>1x to 3x ULN), moderate (>3x to 5x ULN), or severe (>5x ULN). Significant liver injury (SLI) was defined as moderate to severe LI. Univariate analysis of SLI predictors was performed. The impact of LI on clinical outcomes was determined and adjusted for known predictors -age, sex, and comorbidities.

Results

Of the 1,131 patients, 565 (50.04%) developed LI. SLI was associated with male sex, alcohol use, chronic liver disease, increasing COVID-19 severity, high bilirubin, AST, LDH, CRP, and low lymphocyte count and albumin. An increasing degree of LI correlated with ICU admission. Only severe LI was associated with the risk of invasive ventilation (OR: 3.54, p=0.01) and mortality (OR: 2.76, p=0.01). Severe LI, male sex, cardiovascular disease, and malignancy were associated with longer hospital stay among survivors.

Conclusion

The liver injury occurred commonly among COVID-19 patients and was associated with important clinicodemographic characteristics. Severe liver injury increases the risk of adverse outcomes among hospitalized patients.

Research landscape on COVID-19 and liver dysfunction: A bibliometric analysis

BACKGROUND

The global spread of severe acute respiratory syndrome coronavirus 2, responsible for coronavirus disease 2019 (COVID-19), poses a significant risk to public health. Beyond the respiratory issues initially associated with the condition, severe cases of COVID-19 can also lead to complications in other organs, including the liver. Patients with severe COVID-19 may exhibit various clinical signs of liver dysfunction, ranging from minor elevations in liver enzymes without symptoms to more serious cases of impaired liver function. Liver damage is more commonly observed in patients with severe or critical forms of the disease.

AIM

To present the research landscape on COVID-19 and liver dysfunction while also offering valuable insights into the prominent areas of interest within this particular domain.

METHODS

On 18 February 2023, Scopus was utilised to conduct a comprehensive exploration of the relationship between COVID-19 and the liver dysfunction. The investigation encompassed the period from 1 January 2020 to 31 December 2022. Primary sources were meticulously examined and organised in a Microsoft Excel 2013 spreadsheet, categorised by journal, institution, funding agency, country and citation type. VOSviewer version 1.6.18 was employed to explore the prominent topics and knowledge network related to the subject.

RESULTS

There were 2336 publications on COVID-19 and liver dysfunction analysed in this study, of which 558 were published in 2020, 891 in 2021 and 887 in 2022. Researchers from 111 different countries participated in the retrieved documents. The United States contributed the most studies, with 497 documents, representing 21.28% of the total, followed by China with 393 documents (16.82%) and Italy with 255 documents (10.92%). In the context of research related to COVID-19 and the liver, co-occurrence analysis identified three distinct clusters of topics: (1) 'COVID-19 vaccines in liver transplant recipients'; (2) 'liver function tests as a predictor of the severity and clinical outcomes in hospitalised patients'; and (3) 'care of patients with liver disease during the COVID-19 pandemic'.

CONCLUSION

This bibliometric study provides a comprehensive overview of liver-related publications in COVID-19 research over the past 3 years. This study highlights the significant contributions of high-income nations, particularly the United States, China, and Italy, to the production of liver-related scholarly literature in this field. Most of the articles focused on liver dysfunction in patients with COVID-19 and the implications of the virus for gastroenterologists and hepatologists.

Meta-analysis of liver injury in patients with COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) is a major public health problem threatening human health. It can lead to multiple system complications, among which liver damage is also a common complication of COVID-19. The pathogenesis of liver injury is complex and involves the interaction of multiple factors. This study aims to investigate the incidence and risk factors of liver injury in COVID-19 patients and analyze the impact of liver injury on clinical prognosis of patients, so as to provide corresponding basis for clinical diagnosis and treatment.

METHODS

PubMed and Cochrane Library were searched in computer to collect original studies on liver injury cases, laboratory indicators and clinical outcomes in COVID-19 patients. Articles were screened according to inclusion and exclusion criteria, and data were meta-analyzed using Stata12.0 software.

RESULTS

A total of 49 studies, including 23,611 patients with COVID-19, had a prevalence of liver injury of 39.63%. Subgroup analysis found that patients in the Americas had the highest incidence of liver injury at 43.7% and lowest in Africa (25.99%). The vast majority of liver injury is manifested by aminotransferase or bilirubin levels greater than 1 times the upper limit of normal (49.16%). The older the age, the male, the associated chronic liver disease, and the higher the levels of white blood cells, neutrophils, and C-reactive protein, the higher the risk of liver injury. The use of hormones, hydroxychloroquine, and tocilizumab increases the risk of liver injury. Patients with concurrent liver injury have longer hospital stays, are more likely to progress to severe cases, and have a higher risk of death than patients without liver injury.

CONCLUSION

The incidence of liver injury in COVID-19 patients was high, affected by age, gender, chronic liver disease, inflammatory state and medication, and patients with liver injury were hospitalized longer and were more likely to have a poor prognosis. Therefore, clinical attention should be paid to early intervention.

Liver in infections: a single-cell and spatial transcriptomics perspective

The liver is an immune organ that plays a vital role in the detection, capture, and clearance of pathogens and foreign antigens that invade the human body. During acute and chronic infections, the liver transforms from a tolerant to an active immune state. The defence mechanism of the liver mainly depends on a complicated network of intrahepatic and translocated immune cells and non-immune cells. Therefore, a comprehensive liver cell atlas in both healthy and diseased states is needed for new therapeutic target development and disease intervention improvement. With the development of high-throughput single-cell technology, we can now decipher heterogeneity, differentiation, and intercellular communication at the single-cell level in sophisticated organs and complicated diseases. In this concise review, we aimed to summarise the advancement of emerging high-throughput single-cell technologies and re-define our understanding of liver function towards infections, including hepatitis B virus, hepatitis C virus, Plasmodium, schistosomiasis, endotoxemia, and corona virus disease 2019 (COVID-19). We also unravel previously unknown pathogenic pathways and disease mechanisms for the development of new therapeutic targets. As high-throughput single-cell technologies mature, their integration into spatial transcriptomics, multiomics, and clinical data analysis will aid in patient stratification and in developing effective treatment plans for patients with or without liver injury due to infectious diseases.

Targeting patients for early COVID-19 therapy; Pre-infection metabolic dysfunction, polycystic ovary syndrome and risk of severe disease in patients under 65: A Massachusetts community-based observational study

INTRODUCTION

The demographics of those developing severe coronavirus disease (COVID-19) outcomes are shifting to younger patients. In an observational study utilizing electronic health records from a Massachusetts group medical practice, we identified 5025 patients with confirmed COVID-19 from March 1 to December 18, 2020. Of these, 3870 were under 65 years of age. We investigated the hypothesis that pre-infection metabolic or immunologic dysregulation including polycystic ovary syndrome (PCOS) increased risk of serious COVID-19 outcomes in patients under 65 years of age.

MATERIALS AND METHODS

We compared those with COVID-19 related hospitalization or mortality to all other COVID-19 patients, using a case control approach. Using logistic regression and propensity score modeling, we evaluated risk of developing severe COVID-19 outcomes (hospitalization or death) in those with pre-infection comorbidities, metabolic risk factors, or PCOS.

RESULTS

Overall, propensity score matched analyses demonstrated pre-infection elevated liver enzymes alanine aminotransferase (ALT) >40, aspartate aminotransferase (AST) >40 and blood glucose ≥215 mg/dL were associated with more severe COVID-19 outcomes, OR = 1.74 (95% CI 1.31, 2.31); OR = 1.98 (95% CI 1.52, 2.57), and OR = 1.55 (95% CI 1.08, 2.23) respectively. Elevated hemoglobin A1C or blood glucose levels were even stronger risk factors for severe COVID-19 outcomes among those aged < 65, OR = 2.31 (95% CI 1.14, 4.66) and OR = 2.42 (95% CI 1.29, 4.56), respectively. In logistic regression models, women aged < 65 with PCOS demonstrated more than a four-fold increased risk of severe COVID-19, OR 4.64 (95% CI 1.98, 10.88).

CONCLUSION

Increased risk of severe COVID-19 outcomes in those < age 65 with pre-infection indicators of metabolic dysfunction heightens the importance of monitoring pre-infection indicators in younger patients for prevention and early treatment. The PCOS finding deserves further investigation. Meanwhile women who suffer from PCOS should be carefully evaluated and prioritized for earlier COVID-19 treatment and vaccination.

COVID-19 and severity of liver diseases: Possible crosstalk and clinical implications

COVID-19-infected individuals and those who recovered from the infection have been demonstrated to have elevated liver enzymes or abnormal liver biochemistries, particularly with preexisting liver diseases, liver metabolic disorders, viral hepatitis, and other hepatic comorbidities. However, possible crosstalk and intricate interplay between COVID-19 and liver disease severity are still elusive, and the available data are murky and confined. Similarly, the syndemic of other blood-borne infectious diseases, chemical-induced liver injuries, and chronic hepatic diseases continued to take lives while showing signs of worsening due to the COVID-19 crisis. Moreover, the pandemic is not over yet and is transitioning to becoming an epidemic in recent years; hence, monitoring liver function tests (LFTs) and assessing hepatic consequences of COVID-19 in patients with or without liver illnesses would be of paramount interest. This pragmatic review explores the correlations between COVID-19 and liver disease severity based on abnormal liver biochemistries and other possible mechanisms in individuals of all ages from the emergence of the COVID-19 pandemic to the post-pandemic period. The review also alludes to clinical perspectives of such interactions to curb overlapping hepatic diseases in people who recovered from the infection or living with long COVID-19.

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.

SARS-CoV-2 induced liver injury: Incidence, risk factors, impact on COVID-19 severity and prognosis in different population groups

Liver is unlikely the key organ driving mortality in coronavirus disease 2019 (COVID-19) however, liver function tests (LFTs) abnormalities are widely observed mostly in moderate and severe cases. According to this review, the overall prevalence of abnormal LFTs in COVID-19 patients ranges from 2.5% to 96.8% worldwide. The geographical variability in the prevalence of underlying diseases is the determinant for the observed discrepancies between East and West. Multifactorial mechanisms are implicated in COVID-19-induced liver injury. Among them, hypercytokinemia with "bystander hepatitis", cytokine storm syndrome with subsequent oxidative stress and endotheliopathy, hypercoagulable state and immuno-thromboinflammation are the most determinant mechanisms leading to tissue injury. Liver hypoxia may also contribute under specific conditions, while direct hepatocyte injury is an emerging mechanism. Except for initially observed severe acute respiratory distress syndrome corona virus-2 (SARS-CoV-2) tropism for cholangiocytes, more recent cumulative data show SARS-CoV-2 virions within hepatocytes and sinusoidal endothelial cells using electron microscopy (EM). The best evidence for hepatocellular invasion by the virus is the identification of replicating SARS-CoV-2 RNA, S protein RNA and viral nucleocapsid protein within hepatocytes using in-situ hybridization and immunostaining with observed intrahepatic presence of SARS-CoV-2 by EM and by in-situ hybridization. New data mostly derived from imaging findings indicate possible long-term sequelae for the liver months after recovery, suggesting a post-COVID-19 persistent live injury.

The Intersection of COVID-19 and Metabolic-Associated Fatty Liver Disease: An Overview of the Current Evidence

The global population is currently experiencing the impact of the SARS-CoV-2 coronavirus, which has caused the Coronavirus Disease 2019 (COVID-19) pandemic. With our profound comprehension of COVID-19, encompassing the involvement sequence of the respiratory tract, gastrointestinal system, and cardiovascular apparatus, the multiorgan symptoms of this infectious disease have been discerned. Metabolic-associated fatty liver disease (MAFLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a pervasive public health concern intricately linked with metabolic dysregulation and estimated to afflict one-fourth of the global adult population. The burgeoning focus on the association between COVID-19 and MAFLD is justified by the potential role of the latter as a risk factor for both SARS-CoV-2 infection and the subsequent emergence of severe COVID-19 symptoms. Investigations have suggested that changes in both innate and adaptive immune responses among MAFLD patients may play a role in determining the severity of COVID-19. The remarkable similarities observed in the cytokine pathways implicated in both diseases imply the existence of shared mechanisms governing the chronic inflammatory responses characterizing these conditions. The effect of MAFLD on the severity of COVID-19 illness remains uncertain, as indicated by conflicting results in cohort investigations.

Features of Liver Injury in COVID-19 Pathophysiological, Biological and Clinical Particularities

The outbreak of the coronavirus pandemic in March 2020 has caused unprecedented pressure on public health and healthcare. The spectrum of COVID-19 onset is large, from mild cases with minor symptoms to severe forms with multi-organ dysfunction and death. In COVID-19, multiple organ damage has been described, including lung damage, acute kidney injury, liver damage, stroke, cardiovascular and digestive tract disorders. The aspects of liver injury are different, sometimes presenting with only a slight increase in liver enzymes, but sometimes with severe liver injury, leading to acute liver failure requiring liver transplantation. In patients with chronic liver disease, especially liver cirrhosis, immune dysfunction can increase the risk of infection. Immune dysfunction has a multifactorial physiopathological mechanism, implying a complement system and macrophage activation, lymphocyte and neutrophil activity dysfunction, and intestinal dysbiosis. This review aims to evaluate the most relevant studies published in the last years related to the etiopathogenetic, biochemical, and histological aspects of liver injury in patients diagnosed with COVID-19. Liver damage is more evident in patients with underlying chronic liver disease, with a significantly higher risk of developing severe outcomes of COVID-19 and death. Systemic inflammation, coagulation disorders, endothelial damage, and immune dysfunction explain the pathogenic mechanisms involved in impaired liver function. Although various mechanisms of action of SARS-CoV-2 on the liver cell have been studied, the impact of the direct viral effect on hepatocytes is not yet established.

TNFα aggravates detrimental effects of SARS-CoV-2 infection in the liver

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus does not only lead to pulmonary infection but can also infect other organs such as the gut, the kidney, or the liver. Recent studies confirmed that severe cases of COVID-19 are often associated with liver damage and liver failure, as well as the systemic upregulation of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFα). However, the impact these immune mediators in the liver have on patient survival during SARS-CoV-2 infection is currently unknown. Here, by performing a post-mortem analysis of 45 patients that died from a SARS-CoV-2 infection, we find that an increased expression of TNFA in the liver is associated with elevated mortality. Using publicly available single-cell sequencing datasets, we determined that Kupffer cells and monocytes are the main sources of this TNFα production. Further analysis revealed that TNFα signaling led to the upregulation of pro-inflammatory genes that are associated with an unfavorable outcome. Moreover, high levels of TNFA in the liver were associated with lower levels of interferon alpha and interferon beta. Thus, TNFα signaling in the infected SARS-CoV-2 liver correlates with reduced interferon levels and overall survival time.

Liver injury associated with the severity of COVID-19: A meta-analysis

Background

The current 2019 novel coronavirus disease (COVID-19) pandemic is a major threat to global health. It is currently uncertain whether and how liver injury affects the severity of COVID-19. Therefore, we conducted a meta-analysis to determine the association between liver injury and the severity of COVID-19.

Methods

A systematic search of the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2022, was performed to analyse the reported liver chemistry data for patients diagnosed with COVID-19. The pooled odds ratio (OR), weighted mean difference (WMD) and 95% confidence interval (95% CI) were assessed using a random-effects model. Furthermore, publication bias and sensitivity were analyzed.

Results

Forty-six studies with 28,663 patients were included. The pooled WMDs of alanine aminotransferase (WMD = 12.87 U/L, 95% CI: 10.52-15.23, I ² = 99.2%), aspartate aminotransferase (WMD = 13.98 U/L, 95% CI: 12.13-15.83, I ² = 98.2%), gamma-glutamyl transpeptidase (WMD = 20.67 U/L, 95% CI: 14.24-27.10, I ² = 98.8%), total bilirubin (WMD = 2.98 μmol/L, 95% CI: 1.98-3.99, I ² = 99.4%), and prothrombin time (WMD = 0.84 s, 95% CI: 0.46-1.23, I ² = 99.4%) were significantly higher and that of albumin was lower (WMD = -4.52 g/L, 95% CI: -6.28 to -2.75, I ² = 99.9%) in severe cases. Moreover, the pooled OR of mortality was higher in patients with liver injury (OR = 2.72, 95% CI: 1.18-6.27, I ² = 71.6%).

Conclusions

Hepatocellular injury, liver metabolic, and synthetic function abnormality were observed in severe COVID-19. From a clinical perspective, liver injury has potential as a prognostic biomarker for screening severely affected patients at early disease stages.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, Identifier: CRD42022325206.

Association between COVID-19 and chronic liver disease: Mechanism, diagnosis, damage, and treatment

As the outbreak evolves, our understanding of the consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the resulting coronavirus disease 2019 (COVID-19) on the liver has grown. In this review, we discussed the hepatotropic nature of SARS-CoV-2 and described the distribution of receptors for SARS-CoV-2 (e.g., angiotensin-converting enzyme 2) in the vascular endothelium and cholangiocytes of the liver. Also, we proposed mechanisms for possible viral entry that mediate liver injury, such as liver fibrosis. Due to SARS-CoV-2-induced liver damage, many COVID-19 patients develop liver dysfunction, mainly characterized by moderately elevated serum aminotransferase levels. Patients with chronic liver disease (CLD), such as cirrhosis, hepatocellular carcinoma, nonalcoholic fatty liver disease, and viral hepatitis, are also sensitive to SARS-CoV-2 infection. We discussed the longer disease duration and higher mortality following SARS-CoV-2 infection in CLD patients. Correspondingly, relevant risk factors and possible mechanisms were proposed, including cirrhosis-related immune dysfunction and liver deco-mpensation. Finally, we discussed the potential hepatotoxicity of COVID-19-related vaccines and drugs, which influence the treatment of CLD patients with SARS-CoV-2 infection. In addition, we suggested that COVID-19 vaccines in terms of immunogenicity, duration of protection, and long-term safety for CLD patients need to be further researched. The diagnosis and treatment for liver injury caused by COVID-19 were also analyzed in this review.

Diagnostic performance of lactate dehydrogenase (LDH) isoenzymes levels for the severity of COVID-19

Background

Lactate dehydrogenase (LDH) levels predict coronavirus disease 2019 (COVID-19) severity. We investigated LDH isoenzyme levels to identify the tissue responsible for serum LDH elevation in patients with COVID-19.

Methods

Hospitalised COVID-19 patients with serum LDH levels exceeding the upper reference limit included. LDH isoenzymes were detected quantitatively on agarose gels. The radiological severity of lung involvement on computed tomography was scored as 0-5 for each lobe (total possible score, 0-25). Disease severity was determined using the World Health Organization (WHO) clinical progression scale.

Results

In total, 111 patients (mean age, 59.96 ± 16.14), including 43 females (38.7%), were enrolled. The serum levels of total LDH and all five LDH isoenzymes were significantly higher in the severe group. The levels of all LDH isoenzymes excluding LDH5 positively correlated with the WHO score. LDH3 levels correlated with chest computed tomography findings (r² = 0.267, p = 0.005). On multivariate analysis, LDH3 was an independent risk factor for the deterioration of COVID-19.

Conclusions

LDH3 appears to be an independent risk factor for deterioration in patients with COVID-19. LDH elevation in patients with COVID-19 predominantly resulted from lung, liver and muscle damage.

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 liver injury: An ongoing challenge

The new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in December 2019, in Wuhan, China. The virus was rapidly spread worldwide, causing coronavirus disease 2019 (COVID-19) pandemic. Although COVID-19 is presented, usually, with typical respiratory symptoms (i.e., dyspnea, cough) and fever, extrapulmonary manifestations are also encountered. Liver injury is a common feature in patients with COVID-19 and ranges from mild and temporary elevation of liver enzymes to severe liver injury and, even, acute liver failure. The pathogenesis of liver damage is not clearly defined; multiple mechanisms contribute to liver disorder, including direct cytopathic viral effect, cytokine storm and immune-mediated hepatitis, hypoxic injury, and drug-induced liver toxicity. Patients with underlying chronic liver disease (i.e., cirrhosis, non-alcoholic fatty liver disease, alcohol-related liver disease, hepatocellular carcinoma, etc.) may have greater risk to develop both severe COVID-19 and further liver deterioration, and, as a consequence, certain issues should be considered during disease management. The aim of this review is to present the prevalence, clinical manifestation and pathophysiological mechanisms of liver injury in patients with SARS-CoV-2 infection. Moreover, we overview the association between chronic liver disease and SARS-CoV-2 infection and we briefly discuss the management of liver injury during COVID-19.

MINIMAL LIVER ENZYMES ABNORMALITIES AT ADMISSION ARE RELATED TO SEVERE COVID-19 CLINICAL COURSE IN A LARGE BRAZILIAN COHORT

BACKGROUND

COVID-19 is a multisystemic disease, primarily affecting the respiratory system. Liver involvement is frequent, but the impact on the clinical course and outcomes are controversial.

OBJECTIVE

The aim was to assess liver function at the admission and evaluate its effects on severity and mortality in hospitalized patients with COVID-19.

METHODS

This is a retrospective study of hospitalized patients in a tertiary hospital in Brazil, with a PCR-confirmed SARS-CoV-2 infection between April and October 2020. 1080 out of 1229 patients had liver enzymes on admission and were divided in two cohorts, based on the presence or absence of abnormal liver enzymes (ALE). Demographic, clinical, laboratory, imaging, clinical severity, and mortality were evaluated. Patients were followed until discharge, death or transfer to another institution.

RESULTS

Median age was 60 years and 51.5% were male. The more frequent comorbidities were hypertension (51.2%), and diabetes (31.6%). Chronic liver disease and cirrhosis were present in 8.6% and 2.3%, respectively. ALE (aminotransferases higher than 40 IU/L) were present in 56.9% of patients [mild (1-2 times): 63.9%; moderate (2-5 times): 29.8%; severe (>5 times): 6.3%]. Male gender [RR 1.49, P=0.007], increased total bilirubin [RR 1.18, P<0.001] and chronic liver disease [RR 1.47, P=0.015] were predictors of abnormal aminotransferases on admission. Patients with ALE had a higher risk of disease severity [RR 1.19; P=0.004]. There was no association among ALE and mortality.

CONCLUSION

ALE is common in COVID-19 hospitalized patients and were independently correlated with severe COVID-19. Even mild ALE at admission may be a severity prognostic marker.

HCV Infection Increases the Expression of ACE2 Receptor, Leading to Enhanced Entry of Both HCV and SARS-CoV-2 into Hepatocytes and a Coinfection State

Recent studies suggest the enhancement of liver injury in COVID-19 patients infected with Hepatitis C virus (HCV). Hepatocytes express low levels of angiotensin-converting enzyme 2 (ACE2), the SARS-CoV-2 entry receptor, raising the possibility of HCV-SARS-CoV-2 coinfection in the liver. This work aimed to explore whether HCV and SARS-CoV-2 coinfect hepatocytes and the interplay between these viruses. We demonstrate that SARS-CoV-2 coinfects HCV-infected Huh7.5 (Huh7.5HCV) cells. Both viruses replicated efficiently in the coinfected cells, with HCV replication enhanced in coinfected compared to HCV-mono-infected cells. Strikingly, Huh7.5HCV cells were eight fold more susceptible to SARS-CoV-2 pseudoviruses than naive Huh7.5 cells, suggesting enhanced SARS-CoV-2 entry into HCV-preinfected hepatocytes. In addition, we observed increased binding of spike receptor-binding domain (RBD) protein to Huh7.5HCV cells, as well as enhanced cell-to-cell fusion of Huh7.5HCV cells with spike-expressing Huh7.5 cells. We explored the mechanism of enhanced SARS-CoV-2 entry and identified an increased ACE2 mRNA and protein levels in Huh7.5HCV cells, primary hepatocytes, and in data from infected liver biopsies obtained from database. Importantly, higher expression of ACE2 increased HCV infection by enhancing its binding to the host cell, underscoring its role in the HCV life cycle as well. Transcriptome analysis revealed that shared host signaling pathways were induced in HCV-SARS-CoV-2 coinfection. This study revealed complex interactions between HCV and SARS-CoV-2 infections in hepatocytes, which may lead to the increased liver damage recently reported in HCV-positive COVID-19 patients. IMPORTANCE Here, we provide the first experimental evidence for the coexistence of SARS-CoV-2 infection with HCV, and the interplay between them. The study revealed a complex relationship of enhancement between the two viruses, where HCV infection increased the expression of the SARS-CoV-2 entry receptor ACE2, thus facilitating SARS-CoV-2 entry, and potentially, also HCV entry. Thereafter, SARS-CoV-2 infection enhanced HCV replication in hepatocytes. This study may explain the aggravation of liver damage that was recently reported in COVID-19 patients with HCV coinfection and suggests preinfection with HCV as a risk factor for severe COVID-19. Moreover, it highlights the possible importance of HCV treatment for coinfected patients. In a broader view, these findings emphasize the importance of identifying coinfecting pathogens that increase the risk of SARS-CoV-2 infection and that may accelerate COVID-19-related co-morbidities.

Liver alterations and detection of SARS-CoV-2 RNA and proteins in COVID-19 autopsies

The most severe alterations in Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection are seen in the lung. However, other organs also are affected. Here, we report histopathologic findings in the liver and detection of viral proteins and RNA in COVID-19 autopsies performed at the Semmelweis University (Budapest, Hungary). Between March 2020 through March 2022, 150 autopsies on patients who died of COVID-19 were analyzed. Cause-of-death categories were formed based on the association with SARS-CoV-2 as strong, contributive, or weak. Samples for histopathologic study were obtained from all organs, fixed in formalin, and embedded in paraffin (FFPE). Immunohistochemical study (IHC) to detect SARS-CoV-2 spike protein and nucleocapsid protein (NP), CD31, claudin-5, factor VIII, macrosialin (CD68), and cytokeratin 7, with reverse transcriptase polymerase chain reaction (RT-PCR), and in situ hybridization (ISH, RNAscope®) for SARS-CoV-2 RNA were conducted using FFPE samples of livers taken from 20 autopsies performed ≤ 2 days postmortem. All glass slides were scanned; the digital images were evaluated by semiquantitative scoring and scores were analyzed statistically. Steatosis, single-cell and focal/zonal hepatocyte necrosis, portal fibrosis, and chronic inflammation were found in varying percentages. Sinusoidal ectasia, endothelial cell disruption, and fibrin-filled sinusoids were seen in all cases; these were assessed semiquantitatively for severity (SEF scored). SEF scores did not correlate with cause-of-death categories (p = 0.92) or with severity of lung alterations (p = 0.96). SARS-CoV-2 RNA was detected in 13/20 cases by PCR and in 9/20 by ISH, with IHC demonstration of spike protein in 4/20 cases and NP in 15/20. Viral RNA and proteins were located in endothelial and Kupffer cells, and in portal macrophages, but not in hepatocytes and cholangiocytes. In conclusion, endothelial damage (SEF scores) was the most common alteration in the liver and was a characteristic, but not specific alteration in COVID-19, suggesting an important role in the pathogenesis of COVID-19-associated liver disease. Detection of SARS-CoV-2 RNA and viral proteins in liver non-parenchymal cells suggests that while the most extended primary viral cytotoxic effect occurs in the lung, viral components are present in other organs too, as in the liver. The necrosis/apoptosis and endothelial damage associated with viral infection in COVID-19 suggest that those patients who survive more severe COVID-19 may face prolonged liver repair and accordingly should be followed regularly in the post-COVID period.

COVID-19 and liver diseases

Coronavirus causes an outbreak of viral pneumonia that spread throughout the world. Liver injury is becoming more widely recognized as a component of the clinical picture of COVID-19 infection. Hepatitis with serum ALT elevation has been reported in up to half of patients. Patients with CLD were at a higher risk of decompensation with liver failure, hospitalization, and mortality. The percentage of acute liver injury (ALI) varied from 5 to 28%. COVID-19 hinders HCV elimination by 2030. It is recommended to continue treatment of chronic HCV and chronic HBV if already receiving treatment. Consider using antiviral therapy to prevent viral flare-ups in patients with occult or resolved HBV and COVID-19 who are receiving immunosuppressive agents. Patients with AIH do not have an increased risk of adverse outcomes even in high-risk areas. There is an association between MAFLD and disease progression. Patients with any type of cancer are at a higher risk of infection and are more likely to develop more severe clinical outcomes. Most societies advise against immunosuppressant modifications in patients with mild COVID-19, whereas in rare cases such as severe lymphopenia, worsening pneumonia, or bacterial or fungal superinfection, reduction or discontinuation of antiproliferative agents and lymphocyte-depleting therapies has been suggested.

COVID-19-induced liver injury in adult patients: A brief overview

Coronavirus disease has spread worldwide since 2019, causing important pandemic issues and various social health problems to date. Little is known about the origin of this virus and the effects it has on extra-pulmonary organs. The different mechanisms of the virus and the influence it has on humans are still being studied, with hopes of finding a cure for the disease and the pathologies associated with the infection. Liver damage caused by coronavirus disease 2019 (COVID-19) is sometimes underestimated and has been of important clinical interest in the past few years. Hepatic dysfunctions can manifest in different forms which can sometimes be mild and without specific signs and symptoms or be severe with important clinical implications. There are several studies that have tried to explain the mechanism of entry (hepatotropism) of the virus into hepatocytes and the effects the virus has on this important organ. What clearly emerges from the current literature is that hepatic injury represents an important clinical aspect in the management of patients infected with COVID-19, especially in frail patients and those with comorbidities. The aim of our brief overview is to summarize the current literature regarding the forms of hepatic damage, complications, mechanisms of pathology, clinical features of liver injury, influence of comorbidities and clinical management in patients with COVID-19 infection.

Single-nucleus transcriptomic profiling of multiple organs in a rhesus macaque model of SARS-CoV-2 infection

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes diverse clinical manifestations and tissue injuries in multiple organs. However, cellular and molecular understanding of SARS-CoV-2 infection-associated pathology and immune defense features in different organs remains incomplete. Here, we profiled approximately 77 000 single-nucleus transcriptomes of the lung, liver, kidney, and cerebral cortex in rhesus macaques ( Macaca mulatta) infected with SARS-CoV-2 and healthy controls. Integrated analysis of the multi-organ dataset suggested that the liver harbored the strongest global transcriptional alterations. We observed prominent impairment in lung epithelial cells, especially in AT2 and ciliated cells, and evident signs of fibrosis in fibroblasts. These lung injury characteristics are similar to those reported in patients with coronavirus disease 2019 (COVID-19). Furthermore, we found suppressed MHC class I/II molecular activity in the lung, inflammatory response in the liver, and activation of the kynurenine pathway, which induced the development of an immunosuppressive microenvironment. Analysis of the kidney dataset highlighted tropism of tubule cells to SARS-CoV-2, and we found membranous nephropathy (an autoimmune disease) caused by podocyte dysregulation. In addition, we identified the pathological states of astrocytes and oligodendrocytes in the cerebral cortex, providing molecular insights into COVID-19-related neurological implications. Overall, our multi-organ single-nucleus transcriptomic survey of SARS-CoV-2-infected rhesus macaques broadens our understanding of disease features and antiviral immune defects caused by SARS-CoV-2 infection, which may facilitate the development of therapeutic interventions for COVID-19.

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.

COVID-19 Pandemic: Insights into Interactions between SARS-CoV-2 Infection and MAFLD

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become an ongoing global health pandemic. Since 2019, the pandemic continues to cast a long shadow on all aspects of our lives, bringing huge health and economic burdens to all societies. With our in-depth understanding of COVID-19, from the initial respiratory tract to the later gastrointestinal tract and cardiovascular systems, the multiorgan involvement of this infectious disease has been discovered. Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly named nonalcoholic fatty liver disease (NAFLD), is a major health issue closely related to metabolic dysfunctions, affecting a quarter of the world's adult population. The association of COVID-19 with MAFLD has received increasing attention, as MAFLD is a potential risk factor for SARS-CoV-2 infection and severe COVID-19 symptoms. In this review, we provide an update on the interactions between COVID-19 and MAFLD and its underlying mechanisms.

COVID-19 and the Liver: Lessons Learnt from the EAST and the WEST, A Year Later

Globally, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus) has been a major cause for significant morbidity and mortality. Since the start of the pandemic, several hepato-biliary manifestations in coronavirus disease 2019 (COVID-19) have been described and unique considerations raised. The review aims to summarize the pathogenesis and hepato-biliary manifestations in COVID-19 and discuss the similarities, contrasting features and disease-specific management across a range of hepato-biliary diseases from the EAST and the WEST. Published studies and regional society guidelines from the EAST and the WEST were comprehensively reviewed and summarized. A wide range of hepato-biliary manifestations, including the infrequent and chronic manifestation of cholangiopathy, has been observed in COVID-19. The pathogenesis of liver injury is multifactorial and with scant evidence for a direct SARS-CoV-2 infection of the liver. Patients with non-alcoholic fatty liver disease, cirrhosis, and liver cancer are potentially at increased risk for severe COVID-19, and there are unique considerations in chronic hepatitis B or C, hepatocellular carcinoma, and in those immunosuppressed such as autoimmune hepatitis or liver transplant recipients. With the surges in SARS-CoV-2 infection, liver transplant activity has variably been impacted. Preliminarily, SARS-CoV-2 vaccines appear to be safe in those with chronic liver disease and in transplant recipients, while emerging data suggest the need for a third dose in immunosuppressed patients. In conclusion, patients with chronic liver disease, particularly cirrhosis, and liver transplant recipients, are vulnerable to severe COVID-19. Over the past year, several unique considerations have been highlighted across a spectrum of hepato-biliary diseases. Vaccination is strongly recommended for those with chronic liver disease and liver transplant recipients.

Coronavirus disease 2019 gastrointestinal and liver manifestations in adults: A review

Coronavirus disease 2019 (COVID-19) is an important health problem that has a serious adverse impact on the global economy and healthcare systems. The virus is not only involved in the respiratory system, but also causes other systemic effects as well as several gastrointestinal and liver issues. Evidence has shown direct viral invasion into the gastrointestinal tissue and supporting vascular network, causing various manifestations such as diarrhea, nausea, gastrointestinal bleeding, and abnormal liver function tests. The degree of gastrointestinal injury, especially in terms of liver involvement, is correlated with disease severity. There is no specific treatment for gastrointestinal involvement, and the symptoms can be managed with supportive therapy. Moreover, increased liver decompensation and mortality can be found in COVID-19-infected patients with coexisting liver disease. As the virus can be identified in gastrointestinal contents, endoscopic procedures during the pandemic should be carefully selected and proper protection strategies should be encouraged to prevent viral transmission.

Abnormal Liver Tests during Hospitalization Predict Mortality in Patients with COVID-19: A Multicenter Study from South America

BACKGROUND

The role of liver function tests (LFT) as prognostic factors in patients admitted with COVID-19 has not been fully investigated, particularly outside resource-rich countries. We aimed at evaluating the prognostic value of abnormal LFT on admission and during hospitalization of patients with COVID-19.

METHODS

We performed a retrospective study that included 298 adult patients hospitalized for COVID-19, between 05/2020 and 02/2021, in 6 hospitals from 5 countries in South America. We analyzed demographic and comorbid variables and laboratory tests on admission and during hospitalization. LFT over twice the upper limit of normal (ALEx2) were also evaluated in relation to a variety of factors on admission and during hospitalization. De novo-ALEx2 was defined as the presence of ALEx2 at one week of hospitalization in patients without ALEx2 on admission. Patients were followed until hospital discharge or death. Multivariable analysis was used to evaluate the association between ALEx2 on admission and during hospitalization and mortality.

RESULTS

Of the total of 298 patients, 60% were male, with a mean age of 60 years, and 74% of patients had at least one comorbidity. Of those, 137 (46%) patients were transferred to the intensive care unit and 66 (22.1%) patients died during hospitalization. ALEx2 on admission was present in 87 (29.2%) patients and was found to be independently associated with 1-week mortality (odds ratio (OR) = 3.55; 95% confidence interval (95%CI) 1.05-12.05). Moreover, 84 (39.8%) out of 211 patients without ALEx2 at admission developed de novo-ALEx2, which was independently associated with mortality during second week of hospitalization (OR = 6.09; 95%CI 1.28-29) and overall mortality (OR = 2.93, 95%CI 1.05-8.19).

CONCLUSIONS

A moderate elevation of LFT during admission was associated with a poor short-term prognosis in patients hospitalized with COVID-19. In addition, moderate elevation of LFT at one week of hospitalization was an independent risk factor for overall mortality in these patients.

A new parameter for predict the clinical outcome of patients with COVID-19 pneumonia: The direct/total bilirubin ratio

AIM

An urgent need to define clinical and laboratory parameters to predict progression to the severe and lethal forms of Coronavirus Disease 2019 (COVID-19). To investigate the direct/total bilirubin ratio (D/TBil), as a novel parameter, to predict the poor survival of COVID-19 Pneumonia.

METHODS

The clinical characteristics and laboratory parameters of hospitalised COVID-19 pneumonia patients were analysed from 20 March to August 1, 2020, in a tertiary hospital, retrospectively. All remarkable variables were selected for a forward stepwise binary logistic regression analysis to define the independent risk factors for mortality.

RESULTS

537 (248 women and 289 men) patients were separated into two groups for analysis: survivors vs deceased. The mean age of the deceased group was statistically significantly higher than the survivor group 72 (30-92) years vs 50 (18-97) years (P < .001). D/TBil, age, gender, hypertension and neutrophil-to-lymphocyte ratio (NLR) variables contributed significantly to the binary logistic regression model. The mortality risk increased 14.6 times in patients with D/TBil > 0.5, and 2.4 times in patients with NLR > 4.

CONCLUSION

D/TBil > 0.5 was associated with a novel parameter to poor survival of COVID-19 on admission. Also, the combination of age, gender, the presence of hypertension, D/TBil and NLR contributed significantly to predicting the poor survival of COVID-19.

An overview of SARS-COV-2-related hepatic injury

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of coronavirus disease 2019 (COVID-19), is highly contagious and has a variety of clinical manifestations, including liver injury. There have been a few reports indicating acute-on chronic liver failure among COVID-19 patients, however, patients with COVID-19-related liver injury are generally asymptomatic and present with a mild to moderate elevation in serum hepatic enzymes. Severe COVID-19 patients have high rates of liver injury with poorer outcomes. The pattern of abnormalities in liver biochemical indicators may be hepatocellular, cholestatic, or mixed. Although the pathogenesis of hepatic injury is not yet completely understood, causes of liver damage include systemic inflammatory response syndrome, ischemia-reperfusion injury, side effects of medications, and underlying chronic liver disease. While viral RNA has been detected in hepatocytes, it remains unknown if the coronavirus has the capacity to cause cytopathic effects in hepatic tissue. Additionally, it is important to remember that the current upheaval to daily life and access to healthcare caused by the COVID-19 pandemic has had a significant and negative effect on other patients with chronic liver disease. The objective of this review was to summarize the current literature on COVID-19-related hepatic injury with an examination of clinical features, potential pathogenesis, and histopathological findings of this entity.

Sources and clinical significance of aspartate aminotransferase increases in COVID-19

BACKGROUND

Aspartate aminotransferase (AST) is often increased in COVID-19 and, in some studies, AST abnormalities were associated with mortality risk.

METHODS

2054 hospitalized COVID-19 patients were studied. To identify sources of AST release, correlations between AST peak values and other biomarkers of tissue damage, i.e., alanine aminotransferase (ALT) for hepatocellular damage, creatine kinase (CK) for muscle damage, lactate dehydrogenase for multiorgan involvement, alkaline phosphatase and γ-glutamyltransferase for cholestatic injury, and C-reactive protein (CRP) for systemic inflammation, were performed and coefficients of determination estimated. The role of AST to predict death and intensive care unit admission during hospitalization was also evaluated. All measurements were performed using standardized assays.

RESULTS

AST was increased in 69% of patients. Increases could be fully explained by summing the effects of hepatocellular injury [AST dependence from ALT, 66.8% [95% confidence interval (CI): 64.5-69.1)] and muscle damage [AST dependence from CK, 42.6% (CI: 39.3-45.8)]. We were unable to demonstrate an independent association of AST increases with worse outcomes.

CONCLUSION

The mechanisms for abnormal AST in COVID-19 are likely multifactorial and a status related to tissue suffering could play a significant role. The clinical significance of AST elevations remains unclear.

A targeted multi-omics approach reveals paraoxonase-1 as a determinant of obesity-associated fatty liver disease

Background

The multifactorial nature of non-alcoholic fatty liver disease cannot be explained solely by genetic factors. Recent evidence revealed that DNA methylation changes take place at proximal promoters within susceptibility genes. This emphasizes the need for integrating multiple data types to provide a better understanding of the disease’s pathogenesis. One such candidate gene is paraoxonase-1 (PON1). Substantial interindividual differences in PON1 are apparent and could influence disease risk later in life. The aim of this study was therefore to determine the different regulatory aspects of PON1 variability and to examine them in relation to the predisposition to obesity-associated fatty liver disease.

Results

A targeted multi-omics approach was applied to investigate the interplay between PON1 genetic variants, promoter methylation, expression profile and enzymatic activity in an adult patient cohort with extensive metabolic and hepatic characterisation including liver biopsy. Alterations in PON1 status were shown to correlate with waist-to-hip ratio and relevant features of liver pathology. Particularly, the regulatory polymorphism rs705379:C > T was strongly associated with more severe liver disease. Multivariable data analysis furthermore indicated a significant association of combined genetic and epigenetic PON1 regulation. This identified relationship postulates a role for DNA methylation as a mediator between PON1 genetics and expression, which is believed to further influence liver disease progression via modifications in PON1 catalytic efficiency.

Conclusions

Our findings demonstrate that vertical data-integration of genetic and epigenetic regulatory mechanisms generated a more in-depth understanding of the molecular basis underlying the development of obesity-associated fatty liver disease. We gained novel insights into how NAFLD classification and outcome are orchestrated, which could not have been obtained by exclusively considering genetic variation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01142-1.

Liver Disease and Coronavirus Disease 2019: From Pathogenesis to Clinical Care

Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus that emerged in late 2019, is posing an unprecedented challenge to global health. Coronavirus disease 2019 (COVID-19), the clinical disease caused by SARS-CoV-2, has a variable presentation ranging from asymptomatic infection to life-threatening acute respiratory distress syndrome and multiorgan failure. Liver involvement is common during COVID-19 and exhibits a spectrum of clinical manifestations from asymptomatic elevations of liver function tests to hepatic decompensation. The presence of abnormal liver tests has been associated with a more severe presentation of COVID-19 disease and overall mortality. Although SARS-CoV-2 RNA has been detected in the liver of patients with COVID-19, it remains unclear whether SARS-CoV-2 productively infects and replicates in liver cells and has a direct liver-pathogenic effect. The cause of liver injury in COVID-19 can be attributed to multiple factors, including virus-induced systemic inflammation, hypoxia, hepatic congestion, and drug-induced liver disease. Among patients with cirrhosis, COVID-19 has been associated with hepatic decompensation and liver-related mortality. Additionally, COVID-19's impact on health care resources can adversely affect delivery of care and outcomes of patients with chronic liver disease. Understanding the underlying mechanisms of liver injury during COVID-19 will be important in the management of patients with COVID-19, especially those with advanced liver disease. This review summarizes our current knowledge of SARS-CoV-2 virus-host interactions in the liver as well the clinical impact of liver disease in COVID-19.

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.

COVID-19 and pediatric fatty liver disease: Is there interplay?

The rapid global spread of coronavirus disease 2019 (COVID-19) infection has become a major health issue with higher morbidity and mortality rates. Besides respiratory symptoms, a growing body of evidence indicates a variety of gastrointestinal manifestations including liver involvement. In this regard, several data supported an association between COVID-19 infection and liver injury in adults, while in children there is compelling but currently limited evidence. In particular, patients with COVID-19 have shown a higher risk of liver injury (mainly expressed as increased transaminase levels or hepatic steatosis). Conversely, a greater risk of more severe forms of COVID-19 infection has been observed in subjects with pre-existing chronic liver diseases. The dramatic interplay between COVID-19 and liver damage has been related to the inflammatory pathways chronically active in patients with nonalcoholic fatty liver disease and acutely in those affected by COVID-19, but other different pathogenic mechanisms have also been supposed. Of note, patients with previous metabolic comorbidities also had a higher risk of severe COVID-19 infection. This emphasizes the pathogenic interrelation of the inflammatory pathways with a dysregulated metabolic milieu in COVID-19 patients. Taking into account the prognostic role of fatty liver in COVID-19 patients and its intrinsic relationship with metabolic abnormalities even in childhood, a strict monitoring of this condition is recommended. We aimed to summarize the most recent evidence regarding the potential interplay between pediatric fatty liver and COVID-19.

Liver Impairment and Hematological Changes in Patients with Chronic Hepatitis C and COVID-19: A Retrospective Study after One Year of Pandemic

Background and Objectives: The COVID-19 pandemic is an ongoing public health emergency. Patients with chronic diseases are at greater risk for complications and poor outcomes. The objective of this study was to investigate the liver function abnormalities and clinical outcomes in patients with COVID-19 and chronic hepatitis C. Materials and Methods: This retrospective, single-center study was conducted on a cohort of 126 patients with a history of hepatitis C, confirmed with COVID-19 between 01 April 2020 and 30 December 2020. Several clinical outcomes were compared between patients with active and non-active HCV infection, and the risks of liver impairment and all-cause mortality in active HCV patients were analyzed using a multivariate logistic regression model. Results: Among 1057 patients under follow-up for chronic HCV infection, 126 (11.9%) were confirmed with COVID-19; of these, 95 (75.4%) were under treatment or achieved SVR, while in the other 31 (24.6%), we found active HCV replication. There was a significantly higher proportion of severe COVID-19 cases in the active HCV group as compared to the non-active HCV group (32.2 vs. 7.3%, p < 0.001). Multivariate analysis showed that age, sex, alanine aminotransferase, C-reactive protein, procalcitonin, and HCV viral load were significant independent risk factors for liver impairment and all-cause mortality. The length of stay in hospital and intensive care unit for COVID-19 was significantly higher in patients with active HCV infection (p-value < 0.001), and a higher proportion of these patients required mechanical ventilation. Conclusions: Active HCV infection is an independent risk factor for all-cause mortality in COVID-19 patients.

Abnormal Liver Function Tests Were Associated With Adverse Clinical Outcomes: An Observational Cohort Study of 2,912 Patients With COVID-19

Background and Aim: The impact of liver function test (LFTs) abnormality on adverse clinical outcomes in coronavirus disease 2019 (COVID-19) patients remains controversial. The aim of this study was to assess the impact of abnormal LFTs on clinical outcomes in a large cohort of hospitalized patients with COVID-19. Methods: We retrospectively collected data on 2,912 consecutive patients with COVID-19 who were admitted to a makeshift hospital in China between 5 February and 23 March 2020. The association between LFTs abnormalities (baseline and peak values) and clinical outcomes was measured by using Cox regression models. Results: On admission 1,414 patients (48.6%) had abnormal LFTs, with alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT) elevation in 662 (22.7%), 221 (7.6%), 52 (1.8%), 135 (4.6%), and 536 (18.5%) patients, respectively, and hypoalbuminemia in 737 (25.3%) patients. During a median 13 (IQR: 8-19) days of hospitalization, 61 patients (2.1%) died, 106 patients (3.6%) admitted to intensive care unit (ICU), and 75 patients (2.6%) required mechanical ventilation. After adjustment for confounders, baseline abnormal LFTs were independently associated with increased risks of mortality (adjusted HR 3.66, 95%CI 1.64-8.19, p = 0.002), ICU admission (adjusted HR 3.12 95%CI 1.86-5.23, p < 0.001), and mechanical ventilation (adjusted HR 3.00, 95%CI 1.63-5.52, p < 0.001), which was homogeneous across the severity of COVID-19 infection. Among the parameters of LTFs, the associations with the outcomes were more pronounced for AST and albumin abnormality. In contrast, ALT elevation was not significantly associated with those outcomes. Similar results were observed for peak values of LFTs during hospitalization. Conclusions: Abnormality of AST, albumin, TBIL, ALP, and GGT but not ALT were independently associated with adverse outcomes.

COVID-19 and the liver: an adverse outcome pathway perspective

Liver damage is observed in up to half of hospitalized COVID-19 patients and can result either from actions of SARS-CoV-2 as such or from pharmacological treatment. The present paper introduces an adverse outcome pathway construct that mechanistically describes the pathways induced by SARS-CoV-2 leading to liver injury. This can be caused by direct binding of the virus and local actions in cholangiocytes, but may also indirectly result from the general state of hypoxia and systemic inflammation in COVID-19 patients. Further research is urgently needed to fill remaining knowledge gaps. This will be anticipated to create a solid basis for future and more targeted development of vaccines and, in particular, therapies.