SARS-CoV-2 infection of the liver directly contributes to hepatic impairment in patients with COVID-19

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.

Pancreatic and Hepatic Injury in COVID-19: A Worse Prognosis in NAFLD Patients?

The novel disease produced by SARS-CoV-2 mainly harms the respiratory tract, but it has shown the capacity to affect multiple organs. Epidemiologic evidence supports the relationship between Coronavirus Disease 2019 (COVID-19) and pancreatic and hepatic injury development, identified by alterations in these organ function markers. In this regard, it is important to ascertain how the current prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) might affect COVID-19 evolution and complications. Although it is not clear how SARS-CoV-2 affects both the pancreas and the liver, a multiplicity of potential pathophysiological mechanisms seem to be implicated; among them, a direct viral-induced injury to the organ involving liver and pancreas ACE2 expression. Additionally, immune system dysregulation, coagulopathies, and drugs used to treat the disease could be key for developing complications associated with the patient's clinical decline. This review aims to provide an overview of the available epidemiologic evidence regarding developing liver and pancreatic alterations in patients with COVID-19, as well as the possible role that NAFLD/NASH might play in the pathophysiological mechanisms underlying some of the complications associated with COVID-19. This review employed a comprehensive search on PubMed using relevant keywords and filters. From the initial 126 articles, those aligning with the research target were selected and evaluated for their methodologies, findings, and conclusions. It sheds light on the potential pathophysiological mechanisms underlying this relationship. As a result, it emphasises the importance of monitoring pancreatic and hepatic function in individuals affected by COVID-19.

SARS-CoV-2 receptor ACE2 is upregulated by fatty acids in human MASH

BACKGROUND & AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) results in steatosis, inflammation (steatohepatitis), and fibrosis. Patients with MASLD more likely develop liver injury in coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As viral RNA has been identified in liver tissues, we studied expression levels and cellular sources of the viral receptor angiotensin-converting enzyme 2 (ACE2) and coreceptors in MASLD and fibroinflammatory liver diseases.

METHODS

We built a transcriptomic MASLD meta-dataset (N = 243) to study SARS-CoV-2 receptor expression and verified results in 161 additional cases of fibroinflammatory liver diseases. We assessed the fibroinflammatory microenvironment by deconvoluting immune cell populations. We studied the cellular sources of ACE2 by multiplex immunohistochemistry followed by high-resolution confocal microscopy (N = 9 fatty livers; N = 7 controls), meta-analysis of two single-cell RNA sequencing datasets (N = 5 cirrhotic livers; N = 14 normal livers), and bulk transcriptomics from 745 primary cell samples. In vitro, we tested ACE2 mRNA expression in primary human hepatocytes treated with inflammatory cytokines, bacterial lipopolysaccharides, or long-chain fatty acids.

RESULTS

We detected ACE2 at the apical and basal poles of hepatocyte chords, in CLEC4M+ liver sinusoidal endothelial cells, the lumen of ABCC2+ bile canaliculi, HepPar-1+-TMPRSS2+ hepatocytes, cholangiocytes, and CD34+ capillary vessels. ACE2 steeply increased between 30 and 50 years of age; was related to liver fat area, inflammation, high immune reactivity, and fibrogenesis; and was upregulated in steatohepatitis. Although ACE2 mRNA was unmodified in alcoholic or viral hepatitis, it was upregulated in fibroinflammatory livers from overweight patients. In vitro, treatment of primary human hepatocytes with inflammatory cytokines alone downregulated but long chain fatty acids upregulated ACE2 mRNA expression.

CONCLUSIONS

Lipid overload in fatty liver disease leads to an increased availability of ACE2 receptors.

IMPACT AND IMPLICATIONS

COVID-19 can be a deadly disease in vulnerable individuals. Patients with fatty liver disease are at a higher risk of experiencing severe COVID-19 and liver injury. Recent studies have indicated that one of the reasons for this vulnerability is the presence of a key cell surface protein called ACE2, which serves as the main SARS-CoV-2 virus receptor. We describe the cellular sources of ACE2 in the liver. In patients with fatty liver disease, ACE2 levels increase with age, liver fat content, fibroinflammatory changes, enhanced positive immune checkpoint levels, and innate immune reactivity. Moreover, we show that long chain fatty acids can induce ACE2 expression in primary human hepatocytes. Understanding the cellular sources of ACE2 in the liver and the factors that influence its availability is crucial. This knowledge will guide further research and help protect potentially vulnerable patients through timely vaccination boosters, dietary adjustments, and improved hygiene practices.

Analysis of SARS-CoV-2 Variant-Specific Serum Antibody Post-Vaccination Utilizing Immortalized Human Hepatocyte-Like Cells (HLC) to Assess Development of Immunity

Background

Our previous studies demonstrated that SARS-CoV-2 spike protein could bind to primary hepatocytes and immortalized Hepatocyte-like cells (HLC) via the asialoglycoprotein receptor-1 (ASGR-1). The binding of biotinylated spike protein could be inhibited by Spike-neutralizing monoclonal antibodies, anti-ASGR-1 antibodies and unlabeled spike protein. The cells were unable to bind Spike S1 and Spike S1 was incapable of blocking labeled Spike protein, suggesting that the Receptor Binding Domain (RBD) was not involved in the binding event. This study was done to investigate the utility of these cells and immortalized alveolar type 2-like (AT-2) cells in studying the development of variant-specific antibodies post-vaccination.

Methods

Serum was collected from 10 individuals pre- and post-vaccination with the J&J, Moderna or Pfizer vaccines. The serum samples were quantified for variant-specific antibodies in a flow cytometry-based immunofluorescent assay utilizing beads coated with biotinylated variant spike proteins. Inhibition of spike protein binding to HLC and AT-2 cells by donor serum was analyzed by immunofluorescent confocal analysis.

Results

All variant spike proteins bound to HLC and AT-2 cells. Post-vaccination serum samples demonstrated increases of SARS-CoV-2 antibody levels from 2 weeks to 2.5 months post-vaccination with associated increased spike-blocking capacity. It was also demonstrated that vaccination with all the available vaccines stimulated antibodies that inhibited binding of all the available variant spike proteins to both HLC and AT-2 cells.

Conclusion

HLC, along with AT-2 cells, provides a useful platform to study the development of neutralizing antibodies post-vaccination. Vaccination with the 3 available vaccines all elicited neutralizing serum antibodies that inhibited binding of each of the variant spike proteins to both AT-2 and HLC cells. This study suggests that inhibition of spike binding to target cells may be a more useful technique to assess immunity than gross quantitation of antibody.

Immunogenicity of mucosal COVID-19 vaccine candidates based on the highly attenuated vesicular stomatitis virus vector (VSVMT) in golden syrian hamster

COVID-19 is caused by coronavirus SARS-CoV-2. Current systemic vaccines generally provide limited protection against viral replication and shedding within the airway. Recombinant VSV (rVSV) is an effective vector which inducing potent and comprehensive immunities. Currently, there are two clinical trials investigating COVID-19 vaccines based on VSV vectors. These vaccines were developed with spike protein of WA1 which administrated intramuscularly. Although intranasal route is ideal for activating mucosal immunity with VSV vector, safety is of concern. Thus, a highly attenuated rVSV with three amino acids mutations in matrix protein (VSVMT) was developed to construct safe mucosal vaccines against multiple SARS-CoV-2 variants of concern. It demonstrated that spike protein mutant lacking 21 amino acids in its cytoplasmic domain could rescue rVSV efficiently. VSVMT indicated improved safeness compared with wild-type VSV as the vector encoding SARS-CoV-2 spike protein. With a single-dosed intranasal inoculation of rVSVΔGMT-SΔ21, potent SARS-CoV-2 specific neutralization antibodies could be stimulated in animals, particularly in term of mucosal and cellular immunity. Strikingly, the chimeric VSV encoding SΔ21 of Delta-variant can induce more potent immune responses compared with those encoding SΔ21 of Omicron- or WA1-strain. VSVMT is a promising platform to develop a mucosal vaccine for countering COVID-19.

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.

The long-term health outcomes, pathophysiological mechanisms and multidisciplinary management of long COVID

There have been hundreds of millions of cases of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the growing population of recovered patients, it is crucial to understand the long-term consequences of the disease and management strategies. Although COVID-19 was initially considered an acute respiratory illness, recent evidence suggests that manifestations including but not limited to those of the cardiovascular, respiratory, neuropsychiatric, gastrointestinal, reproductive, and musculoskeletal systems may persist long after the acute phase. These persistent manifestations, also referred to as long COVID, could impact all patients with COVID-19 across the full spectrum of illness severity. Herein, we comprehensively review the current literature on long COVID, highlighting its epidemiological understanding, the impact of vaccinations, organ-specific sequelae, pathophysiological mechanisms, and multidisciplinary management strategies. In addition, the impact of psychological and psychosomatic factors is also underscored. Despite these crucial findings on long COVID, the current diagnostic and therapeutic strategies based on previous experience and pilot studies remain inadequate, and well-designed clinical trials should be prioritized to validate existing hypotheses. Thus, we propose the primary challenges concerning biological knowledge gaps and efficient remedies as well as discuss the corresponding recommendations.

Non-metabolic causes of steatotic liver disease

Hepatic steatosis is caused by exaggerated hepatic lipid accumulation and is a common histological and radiological finding. Non-alcoholic fatty liver disease (NAFLD), or metabolic dysfunction associated steatotic liver disease (MASLD), is highly associated with metabolic syndrome and represents the most common cause of hepatic steatosis. However, since several comorbidities, lifestyle factors, and drugs can cause hepatic steatosis, MASLD is, to some extent, a diagnosis of exclusion. Nevertheless, initiatives have been taken to encompass positive (instead of negative) criteria for diagnosis - such as the presence of cardiometabolic risk factors together with hepatic steatosis. Nonetheless, before confirming a patient with MASLD, it is essential to map and evaluate other causes of fatty liver disease or steatotic liver disease. Several causes of hepatic steatosis have been identified in studies; however, the study cohorts are scarce and often anecdotal. Additionally, many studies have shown correlation without proving causation, and many are retrospective without reporting relevant patient characteristics and comorbidities - making it difficult to draw conclusions regarding the underlying etiology or present comorbidity of hepatic steatosis. In this narrative review, we aimed to identify and summarize present studies evaluating the impact of the most common and often suggested causes of hepatic steatosis.

Euphorbia factor L1 suppresses breast cancer liver metastasis via DDR1-mediated immune infiltration

Euphorbia factor L1 (EFL1), a lathyrane-type diterpenoid from the medicinal herb Euphorbia lathyris L., has been documented to possess various pharmacologic actives. However, the function of EFL1 on breast cancer is not clear. In this study, we explored the effect and mechanism of EFL1 on breast cancer liver metastasis. Female BALB/c mice were subjected to breast cancer-surgical hepatic implantation (SHI) to establish breast cancer liver metastasis model in vivo. At 10 days post-surgery, mice were administrated with EFL1 once daily for a total of 2 weeks. Serum AST and ALT activities, abdominal circumference, peritoneal fluid, tumor weight and volume were determined to assess liver and mesenteric re-metastasis of breast cancer. H&E staining was used to observe morphology changes in tumor, liver and small intestine tissues. ELISA was applied to observe inflammatory levels. Tumor DDR1 expression and immune infiltration were determined using western blotting, immunohistochemistry and flow cytometer methods. Our results showed that EFL1 administration improved liver function (AST and ALT activities), ascites, liver metastasis and mesenteric re-metastasis in SHI mice. Also, SHI-induced inflammatory cell infiltration and IL-1β, IL-6, TNF-α generation in ascites were decreased by EFL1 treatment. Mechanism study revealed that EFL1 intervention enhanced the ratios of CD4+ and CD8+ and CD49b+(NK) T lymphocytes and decreased Treg cells through downregulating DDR1 in the tumor of SHI mice. Furthermore, overexpression of DDR1 abolished the anti-liver metastasis effect and pro-immune infiltration action of EFL1 in SHI mice. Together, our findings suggested that EFL1 protects against breast cancer liver metastasis in vivo by targeting DDR1-mediated immune infiltration.

SARS-CoV-2 and the liver: clinical and immunological features in chronic liver disease

SARS-CoV-2 infection may affect the liver in healthy individuals but also influences the course of COVID-19 in patients with chronic liver disease (CLD). As described in healthy individuals, a strong SARS-CoV-2-specific adaptive immune response is important for the outcome of COVID-19, however, knowledge on the adaptive immune response in CLD is limited.Here, we review the clinical and immunological features of SARS-CoV-2 infection in individuals with CLD. Acute liver injury occurs in many cases of SARS-CoV-2 infection and may be induced by multiple factors, such as cytokines, direct viral infection or toxic effects of COVID-19 drugs. In individuals with CLD, SARS-CoV-2 infection may have a more severe course and promote decompensation and particularly in patients with cirrhosis. Compared with healthy individuals, the SARS-CoV-2-specific adaptive immune responses is impaired in patients with CLD after both, natural infection and vaccination but improves at least partially after booster vaccination.Following SARS-CoV-2 vaccination, rare cases of acute vaccine-induced liver injury and the development of autoimmune-like hepatitis have been reported. However, the concomitant elevation of liver enzymes is reversible under steroid treatment.

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.

"Multisystem Inflammatory Syndrome in Children" (MIS-C) after COVID-19 Infection in the Metropolitan Area of Nuremberg-Erlangen, Germany-Expectations and Results of a Two-Year Period

BACKGROUND

Multisystemic Inflammatory Syndrome in children (MIS-C) is a rare autoimmune disorder occurring after a latency period following acute SARS-CoV-2 infection. The therapeutic regime of MIS-C is adapted to the therapy of the Kawasaki disease, as clinical symptoms are similar. Since the Kawasaki disease can potentially result in severe symptoms, which may even affect long-term health, it is essential to gain further knowledge about MIS-C. Thus, we aimed to investigate the incidence, symptoms, therapeutical procedure and outcome of MIS-C patients in the metropolitan area of Nuremberg-Erlangen during the SARS-CoV2 pandemic.

MATERIAL AND METHODS

Retrospective analysis of clinical charts of MIS-C patients was carried out at three children's hospitals covering the medical care of the metropolitan area of Nuremberg-Erlangen in Germany. Demographic characteristics and symptoms at first visit, their clinical course, therapeutic regime and outcome were recorded within the time period January 2021-December 2022.

RESULTS

Analysis of 10 patients (5 male, 5 female) with MIS-C resulting in an incidence of 2.14/100.000 children. The median time between COVID-19 infection and admission to hospital was 5 weeks. The median age was 7 years. Symptoms comprised fever (100%), rash (70%), bilateral non-purulent conjunctivitis (70%) and urticaria (20%). At the time of presentation, diagnosis-defining inflammation parameters were increased and the range for C-reactive protein was 4.13 mg/dL to 28 mg/dL, with a median of 24.7 mg/dL. Procalcitonin was initially determined in six patients (1.92 ng/mL to 21.5 ng/mL) with a median value of 5.5 pg/mL. Two patients displayed leukocytosis and two displayed leukopenia. None of the patients presented coronary pathologies. Nine of the ten patients received intravenous immunoglobulin (IVIG) therapy. In addition, patients received intravenous steroids (80%) and acetylsalicylic acid (80%).

CONCLUSION

SARS-CoV virus may rarely exert multiorgan manifestations due to hyperinflammatory immunological processes. Within two years of the COVID-19 pandemic, we identified ten patients with COVID-induced MIS-C in the metropolitan area Nuremberg-Erlangen. In the description of the patient collective, we can confirm that MIS-C is distinguished from the Kawasaki disease by the lack of coronary manifestations. Interestingly, although having monitored all pediatric facilities in the investigated area, we find lower incidences of MIS-C compared to findings in the literature. In conclusion, an overestimation of incidences in the upcoming MIS-C during the pandemic needs to be considered.

Fib-4 score is able to predict intra-hospital mortality in 4 different SARS-COV2 waves

Increased values of the FIB-4 index appear to be associated with poor clinical outcomes in COVID-19 patients. This study aimed to develop and validate predictive mortality models, using data upon admission of hospitalized patients in four COVID-19 waves between March 2020 and January 2022. A single-center cohort study was performed on consecutive adult patients with Covid-19 admitted at the Fondazione Policlinico Gemelli IRCCS (Rome, Italy). Artificial intelligence and big data processing were used to retrieve data. Patients and clinical characteristics of patients with available FIB-4 data derived from the Gemelli Generator Real World Data (G2 RWD) were used to develop predictive mortality models during the four waves of the COVID-19 pandemic. A logistic regression model was applied to the training and test set (75%:25%). The model's performance was assessed by receiver operating characteristic (ROC) curves. A total of 4936 patients were included. Hypertension (38.4%), cancer (12.15%) and diabetes (16.3%) were the most common comorbidities. 23.9% of patients were admitted to ICU, and 12.6% had mechanical ventilation. During the study period, 762 patients (15.4%) died. We developed a multivariable logistic regression model on patient data from all waves, which showed that the FIB-4 score > 2.53 was associated with increased mortality risk (OR = 4.53, 95% CI 2.83-7.25; p ≤ 0.001). These data may be useful in the risk stratification at the admission of hospitalized patients with COVID-19.

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.

Secondary Sclerosing Cholangitis After SARS-CoV2: ICU Ketamine Use or Virus-Specific Biliary Tropism and Injury in the Context of Biliary Ischemia in Critically Ill Patients?

Purpose

From the beginning of the Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV2) pandemic, different cases of a cholangiopathy with features of secondary sclerosing cholangitis in critically ill patients (SSC-CIP) have been reported. Patients developing it are generally recovering from severe Coronavirus disease 19 (COVID-19) and required intensive care unit (ICU) admission and mechanical ventilation. Many of them have been administered with ketamine during their ICU stay. The pathogenesis of this novel disease is still debated, and, since prognosis is poor, efforts are needed in order to better understand it.

Patients and Methods

In this review, we focused our attention on COVID-19 SSC clinical, imaging, and histology findings in order to clarify the different pathogenetic options, particularly in regard of the ischemic-direct viral damage and ketamine-related theories, beginning with a recapitulation of SSC-CIP and ketamine-induced cholangiopathy in abusers. The research has been conducted using PubMed and Google Scholar databases. Key-words were "Secondary Sclerosing Cholangiopathy", "SSC-CIP", "Secondary Sclerosing Cholangiopathy in critically ill patients", "Ketamine and cholangiopathy", "Ketamine abusers and liver disease", "Ketamine-related cholangiopathy", "SARS-CoV2 infection and liver disease", "post Covid-19 secondary sclerosing cholangitis", "Covid-19 cholangiopathy".

Results

Many authors, based on the clinical, histological, imaging, and prognostic features of the disease, have pointed out the similarities between post COVID-19 SSC and SSC-CIP; however, peculiar features in the former were not previously observed. Therefore, a direct viral cytopathic action and SARS-CoV2-related coagulopathy are considered the most likely causes. On the other hand, ketamine, with the available data, cannot be surely linked as the main determinant cause of cholangiopathy. Moreover, ketamine-induced cholangitis (KIC) presentation is different from post COVID-19 SSC. Its role as a cofactor precipitating the disease cannot be ruled out.

Conclusion

Post COVID-19 SSC is a rare clinical entity following severe COVID-19 disease. The most accepted theory is that a sum of different insults determines the disease: biliary ischemia, direct viral damage, toxic bile, possibly worsened by ketamine and hyperinflammation due to the cytokine storm. Given the severe prognosis of the disease, with persistent cholangiopathy, organ failure, and orthotopic liver transplantation (OLT), further study on this novel clinical entity is needed.

Integrated NMR and MS Analysis of the Plasma Metabolome Reveals Major Changes in One-Carbon, Lipid, and Amino Acid Metabolism in Severe and Fatal Cases of COVID-19

Brazil has the second-highest COVID-19 death rate worldwide, and Rio de Janeiro is among the states with the highest rate in the country. Although vaccine coverage has been achieved, it is anticipated that COVID-19 will transition into an endemic disease. It is concerning that the molecular mechanisms underlying clinical evolution from mild to severe disease, as well as the mechanisms leading to long COVID-19, are not yet fully understood. NMR and MS-based metabolomics were used to identify metabolites associated with COVID-19 pathophysiology and disease outcome. Severe COVID-19 cases (n = 35) were enrolled in two reference centers in Rio de Janeiro within 72 h of ICU admission, alongside 12 non-infected control subjects. COVID-19 patients were grouped into survivors (n = 18) and non-survivors (n = 17). Choline-related metabolites, serine, glycine, and betaine, were reduced in severe COVID-19, indicating dysregulation in methyl donors. Non-survivors had higher levels of creatine/creatinine, 4-hydroxyproline, gluconic acid, and N-acetylserine, indicating liver and kidney dysfunction. Several changes were greater in women; thus, patients' sex should be considered in pandemic surveillance to achieve better disease stratification and improve outcomes. These metabolic alterations may be useful to monitor organ (dys) function and to understand the pathophysiology of acute and possibly post-acute COVID-19 syndromes.

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.

The bidirectional relationship between fatty liver disease and COVID-19

COVID-19 and nonalcoholic fatty liver disease (NAFLD) have emerged as global pandemics affecting millions of people worldwide over the past three years. NAFLD is particularly prevalent in individuals with metabolic comorbidities, such as diabetes and obesity, which have been strongly linked to a severe course of Sars-CoV-2 infection. Recently, due to the close association between metabolic abnormalities and NAFLD, the disease has been redefined as metabolic dysfunction-associated fatty liver disease (MAFLD). This review offers an overview of the biological and cellular mechanisms by which COVID-19 can cause liver damage, with a specific focus on the influence of fatty liver in these mechanisms. Additionally, it explores how fatty liver can exacerbate a COVID-19 infection and, conversely, if the presence of COVID-19 may accelerate the development and progression of fatty liver. Finally, the review examines the existing evidence suggesting that NAFLD or MAFLD independently contributes to a heightened severity of COVID-19, while also considering other factors such as age and metabolic comorbidities that may play a role in the disease’s progression.

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

The impact of HBV infection on clinical outcomes of COVID-19 patients: a systematic review and meta-analysis

The impact of hepatitis B virus (HBV) infection on clinical outcomes of coronavirus disease 2019 (COVID-19) remains unclear. The aim of this study is to explore this impact. For this systematic review and meta-analysis, we searched PubMed, Web of Science, Embase, Cochrane library, China National Knowledge Infrastructure (CKNI), China Science and Technology Journal Database (VIP), and Wan Fang database for articles between 1 January 2020 and 1 February 2023. We used the Newcastle-Ottawa Quality Assessment to evaluate the study's quality. A random-effects meta-analysis was performed utilising the rates of severe/critical illness and death in COVID-19 patients with and without HBV infection. Eighteen studies with a total of 40,502 participants met the inclusion criteria. The meta-analysis showed that compared to those without HBV infection, COVID-19 patients with HBV were at increased risk of mortality (OR = 1.65, I2 = 58%, and 95% CI 1.08-2.53) and severity (OR = 1.90, I2 = 44%, and 95% CI 1.62-2.24). The region and gender may influence the outcomes of COVID-19 patients with HBV infection, but it requires more global data to confirm. In conclusion, HBV infection is significantly linked to an increased risk of severity and mortality in COVID-19.

The landscape of abnormal pathway activation confers COVID-19 patients' molecular sequelae earlier than clinical phenotype

Rationale: The 2019 coronavirus disease (COVID-19) pandemic poses a significant threat to human health. After SARS-CoV-2 infection, major clinical concerns are organ damage and possible sequelae. Methods: In this study, we analyzed serum multi-omics data based on population-level, including healthy cohort, non-COVID-19 and COVID-19 covered different severity cohorts. We applied the pseudo-SpatioTemporal Consistency Alignment (pST-CA) strategy to correct for individualized disease course differences, and developed pseudo-deterioration timeline model and pseudo-recovery timeline model based on the "severe index" and "course index". Further, we comprehensively analyzed and discussed the dynamic damage signaling in COVID-19 deterioration and/or recovery, as well as the potential risk of sequelae. Results: The deterioration and course models based on the pST-CA strategy can effectively map the activation of blood molecular signals on cellular, pathway, functional and disease phenotypes in COVID-19 deterioration and throughout the disease course. The models revealed the neurological, cardiovascular, and hepatic toxicity present in SARS-CoV-2. The abundance of differentially expressed proteins and the activity of upstream regulators were comprehensively analyzed and evaluated to predict possible target drugs for SARS-CoV-2. On molecular docking simulation analysis, it was further demonstrated that blocking CEACAM1 is a potential therapeutic target for SARS-CoV-2. Conclusions: Clinically, the risk of organ failure and death in COVID-19 patients rises with increasing number of infections. Individualized sequelae prediction for patients and assessment of individualized intervenable targets and available drugs in combination with the upstream regulator analysis results are of great clinical value.

An Updated Systematic Review and Meta-Analysis of the Association between the De Ritis Ratio and Disease Severity and Mortality in Patients with COVID-19

Patients with Coronavirus disease 2019 (COVID-19) often have elevations in markers of liver injury, particularly serum aspartate transaminase (AST) and alanine transaminase (ALT). Such alterations may affect the AST/ALT ratio (De Ritis ratio) and, potentially, clinical outcomes. We conducted an updated systematic review and meta-analysis of the association between the De Ritis ratio and COVID-19 severity and mortality in hospitalized patients. PubMed, Web of Science, and Scopus were searched between 1 December 2019 and 15 February 2023. The Joanna Briggs Institute Critical Appraisal Checklist and the Grading of Recommendations, Assessment, Development, and Evaluation were used to assess the risk of bias and the certainty of the evidence, respectively. Twenty-four studies were identified. The De Ritis ratio on admission was significantly higher in patients with severe disease and non-survivors vs. patients with non-severe disease and survivors (15 studies, weighted mean difference = 0.36, 95% CI 0.24 to 0.49, p < 0.001). The De Ritis ratio was also associated with severe disease and/or mortality using odds ratios (1.83, 95% CI 1.40 to 2.39, p ˂ 0.001; nine studies). Similar results were observed using hazard ratios (2.36, 95% CI 1.17 to 4.79, p = 0.017; five studies). In six studies, the pooled area under the receiver operating characteristic curve was 0.677 (95% CI 0.612 to 0.743). In our systematic review and meta-analysis, higher De Ritis ratios were significantly associated with severe disease and mortality in COVID-19 patients. Therefore, the De Ritis ratio can be useful for early risk stratification and management in this patient group (PROSPERO registration number: CRD42023406916).

Multi-country outbreak of severe acute hepatitis of unknown origin in children, 2022

AIM

To describe epidemiological characteristics of multi-country outbreak of severe acute hepatitis of unknown origin in children in 2022.

METHODS

A descriptive epidemiological study design was used. The review based on the available information concerning this multi-country outbreak aims to summarise the current knowledge about the severe acute hepatitis of unknown origin in children, highlights the suggested working hypotheses, introduces some of the potential explanations for its occurrence and reports on public health measures undertaken to control the disease.

RESULTS

Since the first 10 cases of severe acute hepatitis of unknown origin in children in the United Kingdom on 5 April 2022, and up until the 29 August 2022, more than 1000 probable cases have been reported in 35 countries in the world. Up to today, 22 children died in this multi-country outbreak. Despite the numerous theories that have been suggested on the possible underlying causes of the outbreak, an association with hepatitis A-E viruses has been excluded. Adenovirus serotype 41 has been detected in numerous cases, which makes it the most likely underlying cause of the disease.

CONCLUSION

Efficient surveillance and comprehension advancements of the epidemiology of this disease are especially important for effective prevention and outbreak response.

Acute hepatitis of unknown origin in children: Behind the statistics

Since April 2022, the world has been witnessing a rapidly spreading outbreak of acute hepatitis of unknown origin in children < 16 years old that has affected several countries around the world. Most of the cases have presented with the clinical picture of severe hepatitis that has led to resorting to liver transplantation in several cases. Despite the numerous theories that have been suggested on the possible underlying etiologies of the outbreak, an association with hepatitis A-E viruses and a link to COVID-19 vaccines have been excluded. Adenovirus serotype 41 has been detected in numerous cases, which makes it the most likely underlying cause of the disease. Nevertheless, other hypotheses are being investigated to justify the severity of the clinical picture, which is not typical of this type of virus. This review aims to summarize the current knowledge about the outbreak, highlight the suggested working hypotheses, and report the public health measures undertaken to tackle the outbreak.

Causal associations between chronic hepatitis B and COVID-19 in East Asian populations

BACKGROUND

The relationship between chronic hepatitis B (CHB) and Coronavirus disease 2019 (COVID-19) has been inconsistent in traditional observational studies.

METHODS

We explored the total causal and direct causal associations between CHB and the three COVID-19 outcomes using univariate and multivariate Mendelian randomization (MR) analyses, respectively. Genome-wide association study datasets for CHB and COVID-19 were obtained from the Japan Biobank and the COVID-19 Host Genetics Initiative, respectively.

RESULTS

Univariate MR analysis showed that CHB increased the risk of SARS-CoV-2 infection (OR = 1.04, 95% CI 1.01-1.07, P = 3.39E-03), hospitalized COVID-19 (OR = 1.10, 95% CI 1.06-1.13, P = 7.31E-08), and severe COVID-19 (OR = 1.16, 95%CI 1.08-1.26, P = 1.43E-04). A series of subsequent sensitivity analyses ensured the stability and reliability of these results. In multivariable MR analyses adjusting for type 2 diabetes, body mass index, basophil count, and smoking, genetically related CHB is still positively associated with increased risk of SARS-CoV-2 infection (OR = 1.06, 95% CI 1.02-1.11, P = 1.44E-03) and hospitalized COVID-19 (OR = 1.12, 95% CI 1.07-1.16, P = 5.13E-07). However, the causal link between CHB and severe COVID-19 was attenuated after adjustment for the above variables. In addition, the MR analysis did not support the causal effect of COVID-19 on CHB.

CONCLUSIONS

This study provides evidence that CHB increases COVID-19 susceptibility and severity among individuals of East Asian ancestry.

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 hyperglycemia is associated with infection of hepatocytes and stimulation of gluconeogenesis

Occurrence of hyperglycemia upon infection is associated with worse clinical outcome in COVID-19 patients. However, it is still unknown whether SARS-CoV-2 directly triggers hyperglycemia. Herein, we interrogated whether and how SARS-CoV-2 causes hyperglycemia by infecting hepatocytes and increasing glucose production. We performed a retrospective cohort study including patients that were admitted at a hospital with suspicion of COVID-19. Clinical and laboratory data were collected from the chart records and daily blood glucose values were analyzed to test the hypothesis on whether COVID-19 was independently associated with hyperglycemia. Blood glucose was collected from a subgroup of nondiabetic patients to assess pancreatic hormones. Postmortem liver biopsies were collected to assess the presence of SARS-CoV-2 and its transporters in hepatocytes. In human hepatocytes, we studied the mechanistic bases of SARS-CoV-2 entrance and its gluconeogenic effect. SARS-CoV-2 infection was independently associated with hyperglycemia, regardless of diabetic history and beta cell function. We detected replicating viruses in human hepatocytes from postmortem liver biopsies and in primary hepatocytes. We found that SARS-CoV-2 variants infected human hepatocytes in vitro with different susceptibility. SARS-CoV-2 infection in hepatocytes yields the release of new infectious viral particles, though not causing cell damage. We showed that infected hepatocytes increase glucose production and this is associated with induction of PEPCK activity. Furthermore, our results demonstrate that SARS-CoV-2 entry in hepatocytes occurs partially through ACE2- and GRP78-dependent mechanisms. SARS-CoV-2 infects and replicates in hepatocytes and exerts a PEPCK-dependent gluconeogenic effect in these cells that potentially is a key cause of hyperglycemia in infected patients.

Mechanisms of severe acute respiratory syndrome coronavirus-2 induced liver damage and alteration of some liver biomarkers: A review

The most serious problem for people suffering from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is liver damage. The liver is a frequently affected organ due to the metabolizing and detoxifying functions of several endogenous and exogenous molecules. In COVID-19-affected individuals, even moderate loss of hepatic function could dramatically affect the therapeutic efficacy of antiviral drugs metabolized in the liver. The clear mechanism of hepatocellular damage from SARS-CoV-2 infection is not fully understood. The main objective of this review is to identify potential mechanisms of SARS-2 induced liver damage, treatment outcomes in SARS-CoV-2-infected patients, and future direction. Electronic databases including Web of Science, Google Scholar, MEDLINE, Scopus, and Cochrane library were used to systematically search without limitation of publication date and status. Observational, retrospective cohort, prospective case-control, cohort studies, cross-sectional studies, or clinical trials were included. Liver damage in coronavirus patients is characterized by histopathological changes and abnormal elevation of some liver function tests. These abnormalities include elevation of Alanine aminotransferase, Aspartate aminotransferase, Gamma-glutamyl transferase, Alkaline phosphatase, and Serum bilirubin levels. Histopathological changes of the liver might consist of complete or partial thrombosis of the portal and sinusoidal vessels, portal tract fibrosis, and focally markedly enlarged and fibrotic hepatocytes. Understanding the fundamental molecular and immunological processes of COVID-19-related liver injury is essential for the selection of appropriate drugs and the logical development of successful treatment.

The Liver Can Deliver: Utility of Hepatic Function Tests as Predictors of Outcome in COVID-19, Influenza and RSV Infections

BACKGROUND

liver test abnormalities have been described in patients with Coronavirus-2019 (COVID-19), and hepatic involvement may correlate with disease severity. With the relaxing of COVID-19 restrictions, seasonal respiratory viruses now circulate alongside SARS-CoV-2.

AIMS

we aimed to compare patterns of abnormal liver function tests in patients suffering from COVID-19 infection and seasonal respiratory viruses: respiratory syncytial virus (RSV) and influenza (A and B).

METHODS

a retrospective cohort study was performed including 4140 patients admitted to a tertiary medical center between 2010-2020. Liver test abnormalities were classified as hepatocellular, cholestatic or mixed type. Clinical outcomes were defined as 30-day mortality and mechanical ventilation.

RESULTS

liver function abnormalities were mild to moderate in most patients, and mainly cholestatic. Hepatocellular injury was far less frequent but had a strong association with adverse clinical outcome in RSV, COVID-19 and influenza (odds ratio 5.29 (CI 1.2-22), 3.45 (CI 1.7-7), 3.1 (CI 1.7-6), respectively) COVID-19 and influenza patients whose liver functions did not improve or alternatively worsened after 48 h had a significantly higher risk of death or ventilation.

CONCLUSION

liver function test abnormalities are frequent among patients with COVID-19 and seasonal respiratory viruses, and are associated with poor clinical outcome. The late liver tests' peak had a twofold risk for adverse outcome. Though cholestatic injury was more common, hepatocellular injury had the greatest prognostic significance 48 h after admission. Our study may provide a viral specific auxiliary prognostic tool for clinicians facing patients with a respiratory virus.

Case report: Acute hepatitis in neonates with COVID-19 during the Omicron SARS-CoV-2 variant wave: a report of four cases

Background

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), first emerging in December 2019 and continuously evolving, poses a considerable challenge worldwide. It was reported in the literature that neonates had mild upper respiratory symptoms and a better outcome after Omicron SARS-CoV-2 variant infection, but there was insufficient data about complications and prognosis.

Case Presentation

In this paper, we present the clinical and laboratory characteristics of four COVID-19 neonate patients with acute hepatitis during the Omicron SARS-CoV-2 variant wave. All patients had a clear history of Omicron exposure and were infected via contact with confirmed caregivers. Low to moderate fever and respiratory symptoms were the primary clinical manifestations, and all patients had a normal liver function at the initial stage of the course. Then, the fever lasted 2 to 4 days, and it was noted that hepatic dysfunction might have occurred 5 to 8 days after the first onset of fever, mainly characterized by moderate ALT and AST elevation (>3 to 10-fold of upper limit). There were no abnormalities in bilirubin levels, blood ammonia, protein synthesis, lipid metabolism, and coagulation. All the patients received hepatoprotective therapy, and transaminase levels gradually decreased to the normal range after 2 to 3 weeks without other complications.

Conclusions

This is the first case series about moderate to severe hepatitis in COVID-19 neonatal patients via horizontal transmission. Besides fever and respiratory symptoms, the clinical doctor should pay much attention to evaluating the risk of liver function injury after SARS-CoV-2 variants infection, which is usually asymptomatic and has a delayed onset.

COVID-19 induced liver injury from a new perspective: Mitochondria

Liver damage is a common sequela of COVID-19 (coronavirus disease 2019), worsening the clinical outcomes. However, the underlying mechanism of COVID-induced liver injury (CiLI) is still not determined. Given the crucial role of mitochondria in hepatocyte metabolism and the emerging evidence denoting SARS-CoV-2 can damage human cell mitochondria, in this mini-review, we hypothesized that CiLI happens following hepatocytes' mitochondrial dysfunction. To this end, we evaluated the histologic, pathophysiologic, transcriptomic, and clinical features of CiLI from the mitochondria' eye view. Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), the causative agent of COVID-19, can damage hepatocytes through direct cytopathic effects or indirectly after the profound inflammatory response. Upon entering the hepatocytes, the RNA and RNA transcripts of SARS-CoV-2 engages the mitochondria. This interaction can disrupt the mitochondrial electron transport chain. In other words, SARS-CoV-2 hijacks the hepatocytes' mitochondria to support its replication. In addition, this process can lead to an improper immune response against SARS-CoV-2. Besides, this review outlines how mitochondrial dysfunction can serve as a prelude to the COVID-associated cytokine storm. Thereafter, we indicate how the nexus between COVID-19 and mitochondria can fill the gap linking CiLI and its risk factors, including old age, male sex, and comorbidities. In conclusion, this concept stresses the importance of mitochondrial metabolism in hepatocyte damage in the context of COVID-19. It notes that boosting mitochondria biogenesis can possibly serve as a prophylactic and therapeutic approach for CiLI. Further studies can reveal this notion.

What can autopsy say about COVID-19? A case series of 60 autopsies

INTRODUCTION

Autopsies in SARS-CoV-2 infected cadavers are mainly performed to distinguish patients who died with SARS-CoV-2 infection from those who died of COVID-19. The aim of the current study is to assess the most frequent autopsy findings in patients who died of COVID-19 and to establish an association with clinical records.

MATERIALS AND METHODS

60 patients died between April 2020 and March 2021 after SARS-CoV-2 infection underwent a full autopsy performed at Fondazione Policlinico Universitario Agostino Gemelli IRCCS (Rome). Ante-mortem diagnosis of SARS-CoV-2 infection was microbiologically confirmed.

RESULTS

55 (92%) of cases had at least a comorbidity. At microscopic examination, 40 (67%) of the patients presented pulmonary intravascular coagulation with an inflammatory pattern. Pulmonary microangiopathy was a rare finding (n = 8; 13%). Myocardiosclerosis was the main heart finding (n = 44; 73%). Liver involvement with congestion and hypotrophy was found in 33 (55%) of cadavers. Renal tubular epithelial exfoliation (n = 12; 20%) and intravascular coagulation (n = 4; 7%) were frequent observations. During hospitalization 31% of patients (n = 19) developed acute kidney injury (AKI).

CONCLUSIONS

Lungs and kidneys have been shown to play a pivotal role in COVID-19. The gradual worsening of renal function and AKI might be the result of the progressive collapse of cardiopulmonary system.

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.

COVID-19 and liver injury: Pathophysiology, risk factors, outcome and management in special populations

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 is an ongoing health concern. In addition to affecting the respiratory system, COVID-19 can potentially damage other systems in the body, leading to extra-pulmonary manifestations. Hepatic manifestations are among the common consequences of COVID-19. Although the precise mechanism of liver injury is still questionable, several mechanisms have been hypothesized, including direct viral effect, cytokine storm, hypoxic-ischemic injury, hypoxia-reperfusion injury, ferroptosis, and hepatotoxic medications. Risk factors of COVID-19-induced liver injury include severe COVID-19 infection, male gender, advanced age, obesity, and underlying diseases. The presentations of liver involvement comprise abnormalities in liver enzymes and radiologic findings, which can be utilized to predict the prognosis. Increased gamma-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase levels with hypoalbuminemia can indicate severe liver injury and anticipate the need for intensive care units’ hospitalization. In imaging, a lower liver-to-spleen ratio and liver computed tomography attenuation may indicate a more severe illness. Furthermore, chronic liver disease patients are at a higher risk for severe disease and death from COVID-19. Nonalcoholic fatty liver disease had the highest risk of advanced COVID-19 disease and death, followed by metabolic-associated fatty liver disease and cirrhosis. In addition to COVID-19-induced liver injury, the pandemic has also altered the epidemiology and pattern of some hepatic diseases, such as alcoholic liver disease and hepatitis B. Therefore, it warrants special vigilance and awareness by healthcare professionals to screen and treat COVID-19-associated liver injury accordingly.

Virus-induced breath biomarkers: A new perspective to study the metabolic responses of COVID-19 vaccinees

Coronavirus disease 2019 (COVID-19) vaccines can protect people from the infection; however, the action mechanism of vaccine-mediated metabolism remains unclear. Herein, we performed breath tests in COVID-19 vaccinees that revealed metabolic reprogramming induced by protective immune responses. In total, 204 breath samples were obtained from COVID-19 vaccinees and non-vaccinated controls, wherein numerous volatile organic compounds (VOCs) were detected by comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry system. Subsequently, 12 VOCs were selected as biomarkers to construct a signature panel using alveolar gradients and machine learning-based procedure. The signature panel could distinguish vaccinees from control group with a high prediction performance (AUC, 0.9953; accuracy, 94.42%). The metabolic pathways of these biomarkers indicated that the host-pathogen interactions enhanced enzymatic activity and microbial metabolism in the liver, lung, and gut, potentially constituting the dominant action mechanism of vaccine-driven metabolic regulation. Thus, our findings of this study highlight the potential of measuring exhaled VOCs as rapid, non-invasive biomarkers of viral infections. Furthermore, breathomics appears as an alternative for safety evaluation of biological agents and disease diagnosis.

Liver manifestations in COVID-19 patients: A review article

The coronavirus disease 2019 (COVID-19) initially presented as a disease that affected the lungs. Then, studies revealed that it intricately affected disparate organs in the human body, with the liver being one of the most affected organs. This review aimed to assess the association between COVID-19 and liver function, shedding light on its clinical implication. However, its exact pathophysiology remains unclear, involving many factors, such as active viral replication in the liver cells, direct cytotoxic effects of the virus on the liver or adverse reactions to viral antigens. Liver symptoms are mild-to-moderate transaminase elevation. In some patients, with underlying liver disease, more serious outcomes are observed. Thus, liver function should be meticulously considered in patients with COVID-19.

The Spectrum of Digestive Tract Histopathologic Findings in the Setting of Severe Acute Respiratory Syndrome Coronavirus-2 Infection: What Pathologists Need to Know

Although the novel severe acute respiratory syndrome coronavirus-2 is known primarily to affect the respiratory system, current evidence supports its capability to infect and induce gastrointestinal tract injury. Data describing the histopathologic alterations of the digestive system in patients infected with severe acute respiratory syndrome coronavirus-2 are becoming more detailed, as the number of studies is increasing and the quality of our insight into the infection and the histopathologic findings is improving. This review highlights the range of pathologic findings that could be observed in gastrointestinal specimens from patients infected with coronavirus disease 2019 and the potential underlying pathogenetic mechanisms of this disease.

Effects of Hepatitis B Virus Infection on Patients with COVID-19: A Meta-Analysis

BACKGROUND

The COVID-19 pandemic has brought new problems to patients infected with hepatitis B virus (HBV).

AIM

We aim to know the effects of HBV infection on patients with COVID-19.

METHODS

We searched PubMed, Embase, and Web of Science for data and utilized Stata 14.0 software for this meta-analysis with a random-effects model. This paper was conducted in alignment with the preferred reporting items for systematic review and meta-analysis (PRISMA) guideline.

RESULTS

In total, 37,696 patients were divided into two groups: 2591 COVID-19 patients infected with HBV in the experimental group and 35,105 COVID-19 patients not infected with HBV in the control group. Our study showed that the in-hospital mortality of the experimental group was significant higher than that of the control group (OR = 2.04, 95% CI 1.49-2.79). We also found that COVID-19 patients infected with HBV were more likely to develop severe disease (OR = 1.90, 95% CI 1.32-2.73) than COVID-19 patients not infected with HBV. Upon measuring alanine aminotransferase (SMD = 0.62, 95% CI 0.25-0.98), aspartate aminotransferase (SMD = 0.60, 95% CI 0.30-0.91), total bilirubin (SMD = 0.45, 95% CI 0.23-0.67), direct bilirubin (SMD = 0.36, 95% CI 0.24-0.47), lactate dehydrogenase (SMD = 0.32, 95% CI 0.18-0.47), we found that HBV infection led to significantly higher laboratory results in COVID-19 patients.

CONCLUSION

COVID-19 patients infected with HBV should receive more attention, and special attention should be given to various liver function indices during treatment.

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.

Update on Covid-19: vaccines, timing of transplant after COVID-19 infection and use of positive donors

PURPOSE OF REVIEW

SARS-CoV-2 resulted in a global pandemic that had a chilling effect on transplantation early in the pandemic and continues to result in significant morbidity and mortality of transplant recipients. Over the past 2.5 years, our understanding of the clinical utility of vaccination and mAbs to prevent COVID-19 in solid organ transplant (SOT) recipients has been studied. Likewise, approach to donors and candidates with SARS-CoV-2 has been better understood. This review will attempt to summarize our current understanding of these important COVID-19 topics.

RECENT FINDINGS

Vaccination against SARS-CoV-2 is effective in reducing the risk of severe disease and death among transplant patients. Unfortunately, humoral and, to a lesser extent, cellular immune response to existing COVID-19 vaccines is reduced in SOT recipients compared with healthy controls. Additional doses of vaccine are required to optimize protection of this population and still may be insufficient in those who are highly immunosuppressed, those receiving belatacept, rituximab and other B-cell active mAbs. Until recently, mAbs were options for the prevention of SARS-CoV-2 but are markedly less effective with recent omicron variants. SARS-CoV-2-infected donors can generally be used for nonlung, nonsmall bowel transplants unless they have died of acute severe COVID-19 or COVID-19-associated clotting disorders.

SUMMARY

Our transplant recipients require a three-dose mRNA or adenovirus-vector and one dose of mRNA vaccine to be optimally protected initially; they then need to receive a bivalent booster 2+ months after completing their initial series. Most nonlung, nonsmall bowel donors with SARS-CoV-2 can be utilized as organ donors.

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.

Histology and cytokine levels in hepatic injury accompanying a case of non-severe COVID-19

The pathogenesis of liver dysfunction that complicates coronavirus disease 2019 (COVID-19) remains unclear, especially in mild to moderate severity cases. In this case, a novel coronavirus infection was detected by polymerase chain reaction (PCR) in a 76-year-old woman hospitalized after presenting with fever. No other abnormal physical findings were observed, and oxygen administration was not required. Chest computed tomography (CT) showed a ground-glass-like and an infiltrative shadow in the right lung, and moderate COVID-19 was diagnosed. Initially, the fever resolved, and PCR turned negative; however, the fever reappeared on hospitalization day 14, and CT showed pneumonia exacerbation accompanied by new onset of fatty liver. Biochemical testing revealed marked liver dysfunction, accompanied by elevated serum interleukin (IL)-6, IL-10, and tumor necrosis factor-α levels. Physical findings and all laboratory parameters improved after conservative treatment, and she was discharged on day 22. A liver biopsy performed 44 days post-discharge showed T-cell-dominant inflammatory cell infiltration, mainly in the portal region. Some hepatocytes showed fatty degeneration.We report a case of moderate COVID-19 in which histological hepatitis persisted after a substantial period had passed since the initial infection had cleared and associated transaminase elevations had resolved, with a comparison of serum cytokine dynamics.

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.

COVID-19 and liver dysfunction in children: Current views and new hypotheses

Coronavirus disease 2019 (COVID-19) poses an extremely serious global impact on public healthcare for individuals of all ages, including children. Increasing evidence has shown that liver abnormalities are commonly found in children with COVID-19, and age-related features in innate and adaptive response have been demonstrated. However, there are few reports and studies on COVID-19 related liver injury in children, and the data are scattered. So that many contradictions have arose. This situation is not only due to the serious ethical issues in studying pediatric patients with COVID-19, but also because of the short duration and wide coverage of the COVID-19 epidemic, the severity and complexity of clinical cases varied, as did the inclusion criteria for case reporting and patient outcomes. Therefore, we totaled the incidences, characteristics and pathomechanism of liver injury in children since the COVID-19 outbreak. The etiology of COVID-19-related liver injury is divided into three categories: (1) The direct mechanism involves severe acute respiratory syndrome coronavirus 2 binding to angiotensin-converting enzyme 2 in the liver or bile duct to exert direct toxicity; (2) the indirect mechanisms include an inflammatory immune response and hypoxia; and (3) COVID-19-related treatments, such as mechanical ventilation and antiviral drugs, may cause liver injury. In summary, this minireview provides fundamental insights into COVID-19 and liver dysfunction in children.

Liver Injury Associated with COVID-19 Infection: Pathogenesis, Histopathology, Prognosis, and Treatment

Liver injury occurs frequently as a consequence of SARS-CoV-2 infection. Direct infection of the liver leads to hepatic impairment with elevated transaminases. In addition, severe COVID-19 is characterized by cytokine release syndrome, which may initiate or exacerbate liver injury. In patients with cirrhosis, SARS-CoV-2 infection is associated with acute-on-chronic liver failure. The Middle East and North Africa (MENA) region is one of the world's regions characterized by a high prevalence of chronic liver diseases. Both parenchymal and vascular types of injury contribute to liver failure in COVID-19, with a myriad of pro-inflammatory cytokines playing a major role in perpetuating liver injury. Additionally, hypoxia and coagulopathy complicate such a condition. This review discusses the risk factors, and the underlying causes of impaired liver functions in COVID-19, with a focus on key players in the pathogenesis of liver injury. It also highlights the histopathological changes encountered in postmortem liver tissues as well as potential predictors and prognostic factors of such injury, in addition to the management strategies to ameliorate liver damage.

Pathologic Characteristics of Digestive Tract and Liver in Patients with Coronavirus Disease 2019

With the high prevalence of coronavirus disease-2019 (COVID-19), there has been increasing understanding of the pathologic changes associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This review summarizes the pathologic changes in the digestive system and liver associated with COVID-19, including the injuries induced by SARS-CoV2 infection of GI epithelial cells and the systemic immune responses. The common digestive manifestations associated with COVID-19 include anorexia, nausea, vomiting, and diarrhea; the clearance of the viruses in COVID-19 patients with digestive symptoms is usually delayed. COVID-19-associated gastrointestinal histopathology is characterized by mucosal damage and lymphocytic infiltration. The most common hepatic changes are steatosis, mild lobular and portal inflammation, congestion/sinusoidal dilatation, lobular necrosis, and cholestasis.