COVID-19 infection and liver injury: Clinical features,biomarkers, potential mechanisms,treatment, and management challenges

It is hypothesized that liver impairment caused by coronavirus disease 2019 (COVID-19) infection might play a central role in severe clinical presentations. Liver injury is closely associated with severe disease and, even with antiviral drugs, have a poor prognosis in COVID-19 patients. In addition to the common hepatobiliary disorders caused by COVID-19, patients with pre-existing liver diseases demand special considerations during the current pandemic. Thus, it is vital that upon clinical presentation, patients with concurrent pre-existing liver disease associated with metabolic dysfunction and COVID-19 be managed properly to prevent liver failure. Careful monitoring and early detection of liver damage through biomarkers after hospitalization for COVID-19 is underscored in all cases, particularly in those with pre-existing metabolic liver injury. The purpose of this study was to determine most recent evidence regarding causality, potential risk factors, and challenges, therapeutic options, and management of COVID-19 infection in vulnerable patients with pre-existing liver injury. This review aims to highlight the current frontier of COVID-19 infection and liver injury and the direction of liver injury in these patients.     

Liver injury in COVID-19: A minireview

In December 2019, an outbreak of unexplained pneumonia was reported in Wuhan, China. The World Health Organization officially named this disease as novel coronavirus disease 2019 (COVID-19). Liver injury was observed in patients with COVID-19, and its severity varied depending on disease severity, geographical area, and patient age. Systemic inflammatory response, immune damage, ischemia-reperfusion injury, viral direct damage, drug induce, mechanical ventilation, and underlying diseases may contribute to liver injury. Although, in most cases, mild liver dysfunction is observed, which is usually temporary and does not require special treatment, the importance of monitoring liver injury should be emphasized for doctors. The risk of COVID-19 infection of liver transplantation recipients caused more and more concerns. In this article, we aimed to review the available literature on liver injury in COVID-19 to highlight the importance of monitoring and treating liver injury in COVID-19.     

Clinical features and potential mechanism of coronavirus disease 2019-associated liver injury

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has posed a serious threat to global public health security. With the increase in the number of confirmed cases globally, the World Health Organization has declared the outbreak of COVID-19 an international public health emergency. Despite atypical pneumonia as the primary symptom, liver dysfunction has also been observed in many clinical cases and is associated with the mortality risk in patients with COVID-19, like severe acute respiratory syndrome and Middle East respiratory syndrome. Here we will provide a schematic overview of the clinical characteristics and the possible mechanisms of liver injury caused by severe acute respiratory syndrome coronavirus 2 infection, which may provide help for optimizing the management of liver injury and reducing mortality in COVID-19 patients.     

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

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

Liver injury in COVID-19: Known and unknown

Since the first report of the coronavirus disease 2019 (COVID-19) in December 2019 in Wuhan, China, the outbreak of the disease is currently continuously evolving. Previous studies have shown varying degrees of liver damage in patients with COVID-19. However, the exact causes of liver injury and the relationship between COVID-19 and liver injury is unclear. This article describes liver injury induced by COVID-19, analyzes its causes, and discusses the treatment and prognosis of liver damage in patients with COVID-19.     

COVID-19 and the digestive system: A comprehensive review

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spreading at an alarming rate, and it has created an unprecedented health emergency threatening tens of millions of people worldwide. Previous studies have indicated that SARS-CoV-2 ribonucleic acid could be detected in the feces of patients even after smear-negative respiratory samples. However, demonstration of confirmed fecal-oral transmission has been difficult. Clinical studies have shown an incidence rate of gastrointestinal (GI) symptoms ranging from 2% to 79.1% in patients with COVID-19. They may precede or accompany respiratory symptoms. The most common GI symptoms included nausea, diarrhea, and abdominal pain. In addition, some patients also had liver injury, pancreatic damage, and even acute mesenteric ischemia/thrombosis. Although the incidence rates reported in different centers were quite different, the digestive system was the clinical component of the COVID-19 section. Studies have shown that angiotensin-converting enzyme 2, the receptor of SARS-CoV-2, was not only expressed in the lungs, but also in the upper esophagus, small intestine, liver, and colon. The possible mechanism of GI symptoms in COVID-19 patients may include direct viral invasion into target cells, dysregulation of angiotensin-converting enzyme 2, immune-mediated tissue injury, and gut dysbiosis caused by microbiota. Additionally, numerous experiences, guidelines, recommendations, and position statements were published or released by different organizations and societies worldwide to optimize the management practice of outpatients, inpatients, and endoscopy in the era of COVID-19. In this review, based on our previous work and relevant literature, we mainly discuss potential fecal-oral transmission, GI manifestations, abdominal imaging findings, relevant pathophysiological mechanisms, and infection control and prevention measures in the time of COVID-19.     

Impact of COVID-19 on liver

The incidence of liver injury after coronavirus disease 2019 (COVID-19) infection ranged from 15%-53%. The mechanism includes direct viral cytopathic effect, cytokinesis, and treatment drug-induced liver injury. The symptoms include nausea, vomiting, diarrhea, and loss of appetite. The laboratory results include increased liver enzyme levels, decreased monocyte count, and longer prothrombin time. The most common imaging findings are hepatomegaly on ultrasound, ground-glass opacity on chest computed tomography (CT), and liver hypodensity and pericholecystic fat stranding on abdominal CT. Patients may also have different presentations and poor outcomes of different liver diseases concomitant with COVID-19 infection. Liver function test (LFT) results should be monitored, and all factors known to cause or predispose liver injury should be investigated while managing the patients. The risks of transfer to an intensive care unit, need for mechanical ventilator support, and acute kidney injury is higher in COVID-19 patients with than without abnormal LFTs. Increased mortality and length of hospital stay are both observed.     

COVID-19: Gastrointestinal manifestations,liver injury and recommendations

Coronavirus disease 2019 (COVID-19) has caused a pandemic that affected all countries with nearly 270 million patients and 5 million deaths, as of as of December, 2021. The severe acute respiratory syndrome coronavirus 2 virus targets the receptor, angiotensin-converting enzyme 2, which is frequently found in human intestinal epithelial cells, bile duct epithelial cells, and liver cells, and all gastrointestinal system organs are affected by COVID-19 infection. The aim of this study is to review the gastrointestinal manifestations and liver damage of COVID-19 infection and investigate the severe COVID-19 infection risk in patients that have chronic gastrointestinal disease, along with current treatment guidelines. A literature search was conducted on electronic databases of PubMed, Scopus, and Cochran Library, consisting of COVID-19, liver injury, gastrointestinal system findings, and treatment. Liver and intestinal involvements are the most common manifestations. Diarrhea, anorexia, nausea/vomiting, abdominal pain are the most frequent symptoms seen in intestinal involvement. Mild hepatitis occurs with elevated levels of transaminases. Gastrointestinal involvement is associated with long hospital stay, severity of the disease, and intensive care unit necessity. Treatments and follow-up of patients with inflammatory bowel diseases, cirrhosis, hepatocellular carcinoma, or liver transplant have been negatively affected during the pandemic. Patients with cirrhosis, hepatocellular carcinoma, auto-immune diseases, or liver transplantation may have a greater risk for severe COVID-19. Diagnostic or therapeutic procedures should be restricted with specific conditions. Telemedicine should be used in non-urgent periodic patient follow up. COVID-19 treatment should not be delayed in patients at the risk group. COVID-19 vaccination should be prioritized in this group.     

Prevention,diagnostic evaluation,management and prognostic implications of liver disease in critically ill patients with COVID-19

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, broke out in December 2019 in Wuhan city of China and spread rapidly worldwide. Therefore, by March 2020, the World Health Organization declared the disease a global pandemic. Apart from the respiratory system, various other organs of the human body are also seriously affected by the virus. Liver injury in patients with a severe form of COVID-19 is estimated to be 14.8%-53.0%. Elevated levels of total bilirubin, aspartate aminotransferase and alanine aminotransferase and low levels of serum albumin and prealbumin are the main laboratory findings. Patients with pre-existing chronic liver disease and cirrhosis are much more prone to develop severe liver injury. This literature review presented the recent scientific findings regarding the pathophysiological mechanisms responsible for liver injury in critically ill patients with COVID-19, the various interactions between drugs used to treat the disease and the function of the liver and the specific tests providing the possibility of early diagnosis of severe liver injury in these patients. Moreover, it highlighted the burden that COVID-19 put on health systems worldwide and its effect on transplant programs and the care provided to critically ill patients in general and particularly to those with chronic liver disease.     

Liver injury in COVID-19: Holds ferritinophagy-mediated ferroptosis accountable

Even in patients without a history of liver disease, liver injury caused by coronavirus disease 2019 (COVID-19) is gradually becoming more common. However, the precise pathophysiological mechanisms behind COVID-19's liver pathogenicity are still not fully understood. We hypothesize that inflammation may become worse by cytokine storms caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Elevated ferritin levels can initiate ferritinophagy mediated by nuclear receptor coactivator 4 (NCOA4), which leads to iron elevation, and ferroptosis. In COVID-19 patients, ferroptosis can be restricted to reduce disease severity and liver damage by targeting NCOA4-mediated ferritinophagy. To confirm the role of ferritinophagy-mediated ferroptosis in SARS-CoV-2 infection, further research is required.     

Liver dysfunction-related COVID-19: A narrative review

The coronavirus 2019 disease (COVID-19) is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2. This disease was designated by the World Health Organization as a pandemic on March 11, 2020, which is not seen before. There are no classical features among the cases of the disease owing to the involvement of nearly all body tissues by the virus. Hepatic involvement is one of the characteristics of the COVID-19 course. There are six possible mechanisms of such involvement: Direct virus injury, drug-induced effect, inflammatory cytokine storm, hypoxia-ischemic destruction, abnormalities in liver function tests, and pre-existing chronic liver diseases. Liver abnormalities are seen commonly in the severe or critical stage of COVID-19. Therefore, these abnormalities determine the COVID-19 severity and carry a high rate of morbidity and mortality. The elderly and patients with comorbidities like diabetes mellitus and hypertension are more vulnerable to liver involvement. Another issue that needs to be disclosed is the liver manifestations following the COVID-19 vaccination, such as autoimmune hepatitis. Of note, complete vaccination with third and fourth booster doses is necessary for patients with previous chronic liver diseases or those who have been subjected to liver transplantation. This review aims to explore the various aspects of liver dysfunction during the COVID-19 course regarding the epidemiological features, predisposing factors, pathophysiological mechanisms, hepatic manifestations due to COVID-19 or following vaccination, role of liver function tests in the assessment of COVID-19 severity, adverse effects of the therapeutic agents for the disease, and prognosis.     

Remarkable gastrointestinal and liver manifestations of COVID-19: A clinical and radiologic overview

The coronavirus disease 2019 (COVID-19) raging around the world still has not been effectively controlled in most countries and regions. As a severe acute respiratory syndrome coronavirus, in addition to the most common infectious pneumonia, it can also cause digestive system disease such as diarrhea, nausea, vomiting, liver function damage, etc. In medical imaging, it manifests as thickening of the intestinal wall, intestinal perforation, pneumoperitoneum, ascites and decreased liver density. Angiotensin-converting enzyme 2 has great significance in COVID-19-related digestive tract diseases. In this review, we summarized the data on the clinical and imaging manifestations of gastrointestinal and liver injury caused by COVID-19 so far and explored its possible pathogenesis.     

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.     

Patterns of liver profile disturbance in patients with COVID-19

Fever and cough are the most common clinical symptoms of coronavirus disease 2019 (COVID-19), but complications (such as pneumonia, respiratory distress syndrome, and multiorgan failure) can occur in people with additional comorbidities. COVID-19 may be a new cause of liver disease, as liver profile disturbance is one of the most common findings among patients. The molecular mechanism underlying this phenomenon, however, is still unknown. In this paper, we review the most current research on the patterns of change in liver profile among patients with COVID-19, the possible explanation for these findings, and the relation to pre-existing liver disease in these patients.     

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

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

Frontiers of COVID-19-related myocarditis as assessed by cardiovascular magnetic resonance

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In some patients, COVID-19 is complicated with myocarditis. Early detection of myocardial injury and timely intervention can significantly improve the clinical outcomes of COVID-19 patients. Although endomyocardial biopsy (EMB) is currently recognized as the ‘gold standard’ for the diagnosis of myocarditis, there are large sampling errors, many complications and a lack of unified diagnostic criteria. In addition, the clinical methods of treating acute and chronic COVID-19-related myocarditis are different. Cardiac magnetic resonance (CMR) can evaluate the morphology of the heart, left and right ventricular functions, myocardial perfusion, capillary leakage and myocardial interstitial fibrosis to provide a noninvasive and radiation-free diagnostic basis for the clinical detection, efficacy and risk assessment, and follow-up observation of COVID-19-related myocarditis. However, for the diagnosis of COVID-19-related myocarditis, the Lake Louise Consensus Criteria may not be fully applicable. COVID-19-related myocarditis is different from myocarditis related to other viral infections in terms of signal intensity and lesion location as assessed by CMR, which is used to visualize myocardial damage, locate lesions and quantify pathological changes based on various sequences. Therefore, the standardized application of CMR to timely and accurately evaluate heart injury in COVID-19-related myocarditis and develop rational treatment strategies could be quite effective in improving the prognosis of patients and preventing potential late-onset effects in convalescent patients with COVID-19.     

Surgical treatment of hepatocellular carcinoma in the era of COVID-19 pandemic: A comprehensive review of current recommendations

The new coronavirus disease 2019 (COVID-19) pandemic has resulted in a global health emergency that has also caused profound changes in the treatment of cancer. The management of hepatocellular carcinoma (HCC) across the world has been modified according to the scarcity of care resources that have been diverted mostly to face the surge of hospitalized COVID-19 patients. Oncological and hepatobiliary societies have drafted recommendations regarding the adaptation of guidelines for the management of HCC to the current healthcare situation. This review focuses on specific recommendations for the surgical treatment of HCC (i.e., hepatic resection and liver transplantation), which still represents the best chance of cure for patients with very early and early HCC. While surgery should be pursued for very selected patients in institutions where standards of care are maintained, alternative or bridging methods, mostly thermoablation and transarterial therapies, can be used until surgery can be performed. The prognosis of patients with HCC largely depends on both the characteristics of the tumour and the stage of underlying liver disease. Risk stratification plays a pivotal role in determining the most appropriate treatment for each case and needs to balance the chance of cure and the risk of COVID-19 infection during hospitalization. Current recommendations have been critically reviewed to provide a reference for best practices in the clinical setting, with adaptation based on pandemic trends and categorization according to COVID-19 prevalence.     

Post-COVID-19 interstitial lung disease presenting with profound hypoxemia: Report of three cases demonstrating a good response to high-dose corticosteroid therapy

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which leads to critical pneumonia, although the clinical courses vary. In some cases, COVID-19 pneumonia causes secondary pulmonary fibrosis, which can retain radiological changes and prolong respiratory symptoms. Interstitial lung disease (ILD) secondary to COVID-19 is thought to be caused by multiple pathologies, such as excessive cytokines and abnormal repair processes elaborated by lung cells (epithelium, mesenchyme, and alveolar macrophages) after lung injury rather than viral invasion itself. Immunosuppression therapy may improve chronic respiratory symptoms and radiological changes in post-COVID-19 ILD, although the treatment is not yet established. Herein, we report three patients with post-COVID-19 ILD who presented with profound hypoxemia that had a good response to high-dose corticosteroid therapy. Further and larger studies are needed to establish post-COVID-19 ILD.     

新型冠状病毒肺炎核酸检测中的假阴性分析及对策

新型冠状病毒肺炎(COVID-19)的疫情引发了全世界的关注。早期诊断对COVID-19的治疗、患者预后尤为关键。临床检验中发现早期的COVID-19患者核酸检测多次呈假阴性,特别是不同时间多次阴性结果后转为阳性,给临床诊断和疾病控制带来极大困扰。该文立足于疫情的早日防控,从临床、检验的不同视角,从标本采集、检测方法、产品稳定性等多方面剖析产生假阴性的可能原因,并且结合临床实践和检测技术,从整合特异性实验室指标,规范标本采集方式和过程,严格检测试剂的监管和审批等方面提出行之有效的方案,旨在为切实降低检测假阴性或假阳性率提供临床参考,为COVID-19临床准确诊断及疫情防控提供有力支撑。     

Hypertransaminasemia in the course of infection with SARS-CoV-2: Incidence and pathogenetic hypothesis

In patients infected with severe acute respiratory syndrome coronavirus 2, the respiratory symptoms, such as fever, cough and dyspnea, are the most frequent clinical manifestations. These patients may also present with less well-defined symptoms like diarrhea, nausea, vomiting and/or abdominal discomfort both at the time of diagnosis and during the clinical course. In a few cases, these symptoms may also present before the appearance of respiratory symptoms. To penetrate the body, Severe acute respiratory syndrome coronavirus 2 uses ACE2 receptors, which are present not only in respiratory epithelium but also in gastrointestinal mucosa and liver cholangiocytes. In several cases, viral RNA is detectable in the stool of patients with coronavirus disease 2019 (COVID-19). The liver damage seems to show a multifactorial origin. About 2%-11% of patients with COVID-19 have known underlying hepatic pathologies. In 14%-53% of COVID-19 cases, there is an alteration of the indices of liver cytolysis and is more frequently observed in severe forms of COVID-19, especially during hospitalization.