Impaired coagulation,liver dysfunction and COVID-19: Discovering an intriguing relationship

Coronavirus disease 2019 (COVID-19) is, at present, one of the most relevant global health problems. In the literature hepatic alterations have been described in COVID-19 patients, and they are mainly represented by worsening of underlying chronic liver disease leading to hepatic decompensation and liver failure with higher mortality. Several potential mechanisms used by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to cause liver damage have been hypothesized. COVID-19 primary liver injury is less common than secondary liver injury. Most of the available data demonstrate how liver damage in SARS-CoV-2 infection is likely due to systemic inflammation, and it is less likely mediated by a cytopathic effect directed on liver cells. Moreover, liver alterations could be caused by hypoxic injury and drugs (antibiotics and non-steroidal anti-inflammatory drugs, remdesivir, tocilizumab, tofacitinib and dexamethasone). SARS-CoV-2 infection can induce multiple vascular district atherothrombosis by affecting simultaneously cerebral, coronary and peripheral vascular beds. Data in the literature highlight how the virus triggers an exaggerated immune response, which added to the cytopathic effect of the virus can induce endothelial damage and a prothrombotic dysregulation of hemostasis. This leads to a higher incidence of symptomatic and confirmed venous thrombosis and of pulmonary embolisms, especially in central, lobar or segmental pulmonary arteries, in COVID-19. There are currently fewer data for arterial thrombosis, while myocardial injury was identified in 7%-17% of patients hospitalized with SARS-CoV-2 infection and 22%-31% in the intensive care unit setting. Available data also revealed a higher occurrence of stroke and more serious forms of peripheral arterial disease in COVID-19 patients. Hemostasis dysregulation is observed during the COVID-19 course. Lower platelet count, mildly increased prothrombin time and increased D-dimer are typical laboratory features of patients with severe SARS-CoV-2 infection, described as “COVID-19 associated coagulopathy.” These alterations are correlated to poor outcomes. Moreover, patients with severe SARS-CoV-2 infection are characterized by high levels of von Willebrand factor with subsequent ADAMTS13 deficiency and impaired fibrinolysis. Platelet hyperreactivity, hypercoagulability and hypofibrinolysis during SARS-CoV-2 infection induce a pathological state named as “immuno-thromboinflammation.” Finally, liver dysfunction and coagulopathy are often observed at the same time in patients with COVID-19. The hypothesis that liver dysfunction could be mediated by microvascular thrombosis has been supported by post-mortem findings and extensive vascular portal and sinusoidal thrombosis observation. Other evidence has shown a correlation between coagulation and liver damage in COVID-19, underlined by the transaminase association with coagulopathy, identified through laboratory markers such as prothrombin time, international normalized ratio, fibrinogen, D-dimer, fibrin/fibrinogen degradation products and platelet count. Other possible mechanisms like immunogenesis of COVID-19 damage or massive pericyte activation with consequent vessel wall fibrosis have been suggested.     

Liver and COVID-19:From care of patients with liver diseases to liver injury

The global pandemic of coronavirus disease 2019(COVID-19) changed dramatically all priorities on medical society and created several challenges for clinicians caring for patients with liver diseases. We performed a comprehensive review about how COVID-19 can affect the liver, the influence of liver diseases on the risk of developing severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and COVID-19 severity and also some strategies to overcome all the challenges clinicians have to face in the management of patients with liver diseases in a period of time when all the focus turned on COVID-19. We analyze the relationship between COVID-19 and non-alcoholic fatty liver disease, alcoholic liver disease, viral hepatitis, autoimmune liver disease, cirrhosis, hepatocellular carcinoma and liver transplantation, as well as the approach to SARS-CoV-2 vaccination.     

COVID-19 and the liver: A brief and core review

Coronavirus disease 2019 has a wide range of clinical spectrum from asymptomatic infection to severe infection resulting in death within a short time. Currently, it is known that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) does not only cause a respiratory tract infection but a more complicated disease that can lead to multiple system involvement including the liver. Herein, we evaluate the epidemiology, the impact of liver injury/ dysfunction on disease prognosis, the pathophysiological mechanisms and management of liver injury. More than one-fourth of the patients have abnormal liver function tests, mostly a mild-to-moderate liver dysfunction. Liver injury is significantly associated with a poor clinical outcome. Direct cytotoxic effect of SARS-CoV-2, the immune response (“cytokine storm”), the complications related to the disease, and drugs used in the treatments are the pathophysiological mechanisms responsible for liver injury. However, the exact mechanism is not yet clearly explained. The binding of SARS-CoV-2 to the angiotensin-converting enzyme 2 receptors and entering the hepatocyte and cholangiocytes can cause cytotoxic effects on the liver. Excessive immune response has an important role in disease progression and causes acute respiratory distress syndrome and multi-organ failures accompanied by liver injury. Treatment drugs, particularly lopinavir/ritonavir, remdesivir and antibiotics are a frequent reason for liver injury. The possible reasons should be meticulously investigated and resolved.     

High prevalence of hepatic steatosis and vascular thrombosis in COVID-19: A systematic review and meta-analysis of autopsy data

BACKGROUNDCoronavirus disease 2019 (COVID-19) disease can frequently affect the liver. Data on hepatic histopathological findings in COVID-19 is scarce.AIMTo characterize hepatic pathological findings in patients with COVID-19.METHODSWe conducted a systematic review with meta-analysis registered on PROSPERO (CRD42020192813), following PRISMA guidelines. Eligible trials were those including patients of any age and COVID-19 diagnosis based on a molecular test. Histopathological reports from deceased COVID-19 patients undergoing autopsy or liver biopsy were reviewed. Articles including less than ten patients were excluded. Proportions were pooled using random-effects models. Q statistic and I² were used to assess heterogeneity and levels of evidence, respectively.RESULTSWe identified 18 studies from 7 countries; all were case reports and case series from autopsies. All the patients were over 15 years old, and 67.2% were male. We performed a meta-analysis of 5 studies, including 116 patients. Pooled prevalence estimates of liver histopathological findings were hepatic steatosis 55.1% [95% confidence interval (CI): 46.2-63.8], congestion of hepatic sinuses 34.7% (95%CI: 7.9-68.4), vascular thrombosis 29.4% (95%CI: 0.4-87.2), fibrosis 20.5% (95%CI: 0.6-57.9), Kupffer cell hyperplasia 13.5% (95%CI: 0.6-54.3), portal inflammation 13.2% (95%CI: 0.1-48.8), and lobular inflammation 11.6% (95%CI: 0.3-35.7). We also identified the presence of venous outflow obstruction, phlebosclerosis of the portal vein, herniated portal vein, periportal abnormal vessels, hemophagocytosis, and necrosis.CONCLUSIONWe found a high prevalence of hepatic steatosis and vascular thrombosis as major histological liver features. Other frequent findings included portal and lobular inflammation and Kupffer cell hyperplasia or proliferation. Further studies are needed to establish the mechanisms and implications of these findings.     

COVID-19, liver dysfunction and pathophysiology: A conceptual discussion

The intra and extracellular pathways of hepatic injury by coronavirus disease 2019 (COVID-19) are still being studied. Understanding them is important to treat this viral disease and other liver and biliary tract disorders. Thus, this paper aims to present three hypotheses about liver injury caused by COVID-19: (1) The interactions between severe acute respiratory syndrome coronavirus 2 spike protein and membrane receptors in the hepatocyte; (2) The dysbiosis and “gut-liver axis” disruption in patients with serious clinical presentations of COVID-19; and (3) The inflammatory response exacerbated through the production of interleukins such as interleukin-6. However, despite these new perspectives, the pathophysiological process of liver injury caused by COVID-19 is still complex and multifactorial. Thus, understanding all these variables is a challenge to science but also the key to propose individualized and effective patient therapies.     

Drug-induced liver injury and COVID-19: A review for clinical practice

Coronavirus disease 2019 (COVID-19) consists of a systemic disease that can present many complications. The infection presents broad clinical symptoms and a high rate of transmissibility. In addition to severe acute respiratory syndrome, the patients manifest complications beyond the respiratory system. The frequency of liver damage in COVID-19 patients ranges from 14.8% to 53% of patients. One should pay attention to drug-induced liver injury (DILI) in patients with COVID-19, especially considering the off-label use of drugs in prophylactic and therapeutic regimens applied on large scales. This review aims to present relevant information on the medication used so far in COVID-19 patients and its possible hepatotoxicity. We reviewed liver damage in patients with COVID-19 on PubMed and Virtual Health Library to investigate DILI cases. Four studies were selected, involving the medicines remdesivir, tocilizumab and a pharmacovigilance analysis study. The hepatotoxicity profile of drugs presented in the literature considers use in accordance to usual posology standards for treatment. However, drugs currently used in the management of COVID-19 follow different dosages and posology than those tested by the pharmaceutical industry. The deficiency of uniformity and standardization in the assessment of hepatotoxicity cases hinders the publication of information and the possibility of comparing information among healthcare professionals. It is suggested that severe liver injury in COVID-19 patients should be reported in pharmacovigilance institutions, and physicians should pay attention to any considerable abnormal liver test elevation as it can demonstrate unknown drug hepatotoxicity. Liver disorders in COVID-19 patients and the use of several concomitant off-label medications — with a potential risk of further damaging the liver - should at least be a warning sign for rapid identification and early intervention, thus preventing liver damage from contributing to severe impairment in patients.     

Liver disease and COVID-19: The link with oxidative stress,antioxidants and nutrition

Varying degrees of liver injuries have been reported in patients infected with the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). In general, oxidative stress is actively involved in initiation and progression of liver damage. The liver metabolizes various compounds that produce free radicals. Maintaining the oxidative/antioxidative balance is important in coronavirus disease 2019 (COVID-19) patients. Antioxidant vitamins, essential trace elements and food compounds, such as polyphenols, appear to be promising agents, with effects in oxidative burst. Deficiency of these nutrients suppresses immune function and increases susceptibility to COVID-19. Daily micronutrient intake is necessary to support anti-inflammatory and antioxidative effects but for immune function may be higher than current recommended dietary intake. Antioxidant supplements (β-carotene, vitamin A, vitamin C, vitamin E, and selenium) could have a potential role in patients with liver damage. Available evidence suggests that supplementing the diet with a combination of micronutrients may help to optimize immune function and reduce the risk of infection. Clinical trials based on the associations of diet and SARS-CoV-2 infection are lacking. Unfortunately, it is not possible to definitively determine the dose, route of administration and best timing to intervene with antioxidants in COVID-19 patients because clinical trials are still ongoing. Until then, hopefully, this review will enable clinicians to understand the impact of micronutrient dietary intake and liver status assessment in COVID-19 patients.     

Comparison of liver biochemical abnormality between COVID-19 patients with liver cirrhosis versus COVID-19 alone and liver cirrhosis alone: A STROBE observational study

Coronavirus disease (COVID-19) patients frequently develop liver biochemical abnormality. However, liver biochemical abnormality in COVID-19 patients with liver cirrhosis is under-recognized.Patients hospitalized during COVID-19 pandemic in China (ie, from February to April 2020) were screened. All of 17 COVID-19 patients with liver cirrhosis consecutively admitted to the Wuhan Huoshenshan Hospital were identified. Meanwhile, 17 age-, sex-, and severity-matched COVID-19 patients without liver cirrhosis admitted to this hospital were selected as a control group; all of 14 cirrhotic patients without COVID-19 consecutively admitted to the Department of Gastroenterology of the General Hospital of Northern Theater Command were selected as another control group. Incidence of liver biochemical abnormality and decompensated events were primarily compared.Among the COVID-19 patients with liver cirrhosis, the incidence of liver biochemical abnormality at admission and during hospitalization were 76.50% and 84.60%, respectively; 7 (41.20%) had decompensated events at admission; 1 was transferred to intensive care unit due to gastrointestinal bleeding. Among the COVID-19 patients without liver cirrhosis, the incidence of liver biochemical abnormality at admission and during hospitalization were 58.80% (P = .271) and 60.00% (P = .150), respectively. Among the cirrhotic patients without COVID-19, the incidence of liver biochemical abnormality at admission and during hospitalization were 69.20% (P = .657) and 81.80% (P = .855), respectively; 11 (78.60%) had decompensated events at admission (P = .036). None died during hospitalization among the three groups.Liver biochemical abnormality is common in COVID-19 patients with liver cirrhosis. Management of decompensated events in cirrhotic patients without COVID-19 should not be neglected during COVID-19 pandemic.     

COVID-19 and liver dysfunction: What nutritionists need to know

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field. Patients with COVID-19 usually have respiratory symptoms. However, liver dysfunction is not an uncommon presentation. Additionally, the degree of liver dysfunction is associated with the severity and prognosis of COVID-19. Prevention, diagnosis, and treatment of malnutrition should be routinely recommended in the management of patients with COVID-19, especially in those with liver dysfunction. Recently, a large number of studies have reported that nutrition therapy measures, including natural dietary supplements, vitamins, minerals and trace elements, and probiotics, might have potential hepatoprotective effects against COVID-19-related liver dysfunction via their antioxidant, antiviral, anti-inflammatory, and positive immunomodulatory effects. This review mainly focuses on the possible relationship between COVID-19 and liver dysfunction, nutritional and metabolic characteristics, nutritional status assessment, and nutrition therapy to provide a reference for the nutritionists while making evidence-based nutritional decisions during the COVID-19 pandemic.     

Liver dysfunction during COVID-19 pandemic: Contributing role of associated factors in disease progression and severity

In December 2019, a new strain of coronavirus was discovered in China, and the World Health Organization declared it a pandemic in March 2020. The majority of people with coronavirus disease 19 (COVID-19) exhibit no or only mild symptoms such as fever, cough, anosmia, and headache. Meanwhile, approximately 15% develop a severe lung infection over the course of 10 d, resulting in respiratory failure, which can lead to multi-organ failure, coagulopathy, and death. Since the beginning of the pandemic, it appears that there has been consideration that pre-existing chronic liver disease may predispose to deprived consequences in conjunction with COVID-19. Furthermore, extensive liver damage has been linked to immune dysfunction and coagulopathy, which leads to a more severe COVID-19 outcome. Besides that, people with COVID-19 frequently have abnormal liver function, with more significant elevations in alanine aminotransferase and aspartate aminotransferase in patients with severe COVID-19 compared to those with mild/moderate disease. This review focuses on the pathogenesis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the liver, as well as the use of liver chemistry as a prognostic tool during COVID-19. We also evaluate the findings for viral infection of hepatocytes, and look into the potential mechanisms behind SARS-CoV-2-related liver damage.     

Correlation between COVID-19 and hepatitis B: A systematic review

BACKGROUNDThere is growing evidence that patients with coronavirus disease 2019 (COVID-19) frequently present with liver impairment. Hepatitis B virus (HBV) remains a major public health threat in current society. Both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HBV can cause liver damage, and current findings on whether HBV infection increases disease severity in COVID-19 patients are inconsistent, and whether SARS-CoV-2 infection accelerates hepatitis B progression or leads to a worse prognosis in hepatitis B patients has not been adequately elucidated.AIMTo explore the complex relationship between COVID-19 and hepatitis B in order to inform the research and management of patients co-infected with SARS-CoV-2 and HBV.METHODSAn experienced information specialist searched the literature in the following online databases: PubMed, China National Knowledge Infrastructure, Google Scholar, Scopus, Wiley, Web of Science, Cochrane, and ScienceDirect. The literature published from December 2019 to September 1, 2022 was included in the search. We also searched medRxiv and bioRxiv for gray literature and manually scanned references of included articles. Articles reporting studies conducted in humans discussing hepatitis B and COVID-19 were included. We excluded duplicate publications. News reports, reports, and other gray literature were included if they contained quantifiable evidence (case reports, findings, and qualitative analysis). Some topics that included HBV or COVID-19 samples but did not have quantitative evidence were excluded from the review.RESULTSA total of 57 studies were eligible and included in this review. They were from 11 countries, of which 33 (57.9%) were from China. Forty-two of the 57 studies reported abnormalities in liver enzymes, three mainly reported abnormalities in blood parameters, four indicated no significant liver function alterations, and another eight studies did not provide data on changes in liver function. Fifty-seven studies were retrospective and the total number of co-infections was 1932, the largest sample size was 7723, and the largest number of co-infections was 353. Most of the studies suggested an interaction between hepatitis B and COVID-19, while 12 studies clearly indicated no interaction between hepatitis B and COVID-19. Six of the 57 studies clearly reported HBV activation. Six studies were related to liver transplant patients.CONCLUSIONThere is some association between COVID-19 and hepatitis B. Future high-quality randomized trials are needed to further elucidate the interaction between COVID-19 and hepatitis B.     

COVID-19 and Indirect Liver Injury: A Narrative Synthesis of the Evidence

The liver is frequently affected by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection. The most common manifestations are mildly elevated alanine aminotransferase and aspartate aminotransferase, with a prevalence of 16-53% among patients. Cases with severe coronavirus disease 2019 (COVID-19) seem to have higher rates of acute liver dysfunction, and the presence of abnormal liver tests at admission signifies a higher risk of severe disease during hospitalization. Patients with chronic liver diseases also have a higher risk of severe disease and mortality (mainly seen in patients with metabolic-associated fatty liver disease). Several pathways of damage have been proposed in the liver involvement of COVID-19 patients; although, the end-cause is most likely multifactorial. Abnormal liver tests have been attributed to the expression of angiotensin-converting enzyme 2 receptors in SARS-CoV-2 infection. This enzyme is expressed widely in cholangiocytes and less in hepatocytes. Other factors attributed to liver damage include drug-induced liver injury, uncontrolled release of proinflammatory molecules (“cytokine storm”), pneumonia-associated hypoxia, and direct damage by the infection. Hepatic steatosis, vascular thrombosis, fibrosis, and inflammatory features (including Kupffer cell hyperplasia) are the most common liver histopathological findings in deceased COVID-19 patients, suggesting important indirect mechanisms of liver damage. In this translational medicine-based narrative review, we summarize the current data on the possible indirect mechanisms involved in liver damage due to COVID-19, the histopathological findings, and the impact of these mechanisms in patients with chronic liver disease.     

Etiology and management of liver injury in patients with COVID-19

The outbreak of novel coronavirus disease 2019(COVID-19) has resulted in global emergence. With the expansion of related research, in addition to respiratory symptoms, digestive system involvement such as nausea, vomiting, and diarrhea have also been reported with COVID-19. Besides, abnormal liver function is also frequent in biochemical tests of COVID-19 patients, which is correlated with the severity and mortality of the disease course. The etiology of liver injury in patients with COVID-19 might include viral immunologic injury, drug-induced liver injury, the systemic inflammatory response, hypoxic hepatitis, and the exacerbation of preexisting liver disease. Although liver injuries in COVID-19 are often transient and reversible, health workers need to pay attention to preexisting liver disease, monitor liver function, strengthen supportive treatment, and reduce the chance of drug-induced liver injury. This article reviews the epidemiological characteristics, etiology, management, and preventive strategies for liver injury in patients with COVID-19.     

COVID-19 and splenectomy: Education matters

Whether COVID-19-related morbidity and mortality are increased in splenectomized patients is unknown. The study by Bianchi et al. suggests increased hospitalizations and mortality rates in splenectomized patients, despite observing similar infection rates when compared to the general population. Commentary on: Bianchi et al. Burden of COVID19 disease and vaccine coverages in Apulian splenectomized patients. A retrospective observational study. Br J Haematol 2023;201:1072–1080.     

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 o...     

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...     

Gastrointestinal and hepatic manifestations of COVID-19:A comprehensive review

The severe acute respiratory syndrome-coronavirus-2(SARS-CoV-2) that causes coronavirus disease-2019(COVID-19) is a global pandemic, manifested by an infectious pneumonia. Although patients primarily present with fever, cough and dyspnea, some patients also develop gastrointestinal(GI) and hepatic manifestations. The most common GI symptoms reported are diarrhea, nausea,vomiting, and abdominal discomfort. Liver chemistry abnormalities are common and include elevation of aspartate transferase, alanine transferase, and total bilirubin. Studies have shown that SARS-CoV-2 infects the GI tract via its viral receptor angiotensin converting enzyme Ⅱ, which is expressed on enterocytes of the ileum and colon. Viral RNA has also been isolated from stool specimens of COVID-19 patients, which raised the concern for fecal-oral transmission in addition to droplet transmission. Although indirect evidence has suggested possible fecal-oral transmission of SARS-CoV-2, more effort is needed to establish the role of the fecal-oral transmission route. Further research will help elucidate the association between patients with underlying GI diseases, such as chronic liver disease and inflammatory bowel disease, and severity of COVID-19. In this review, we summarize the data on GI involvement to date, as well as the impact of COVID-19 on underlying GI diseases.     

Interventions for Improving Long COVID-19 Symptomatology: A Systematic Review

Introduction: Although the understanding of several aspects of long COVID-19 syndrome is increasing, there is limited literature regarding the treatment of these signs and symptoms. The aim of our systematic review was to understand which therapies have proved effective against the symptoms of long COVID-19. Methods: A systematic search for randomized controlled or clinical trials in several databases was conducted through 15 May 2022. Specific inclusion criteria included: (1) intervention studies, either randomized controlled (RCTs) or clinical trials; (2) diagnosis of long COVID-19, according to the World Health Organization criteria; (3) presence of long COVID-19 for at least 12 weeks after SARS-CoV-2 infection. Results: We initially found 1638 articles to screen. After removing 1602 works based on their title/abstract, we considered 35 full texts, and among them, two intervention studies were finally included. The first RCT focused on the greater improvement of treatment combining olfactory rehabilitation with oral supplementation with Palmitoylethanolamide and Luteolin in patients with olfactory dysfunction after COVID-19. The second study evaluated the positive impact of aromatherapy vs. standard care in adult females affected by fatigue. Conclusion: Our systematic review found only two intervention studies focused on patients affected by long COVID-19. More intervention studies are needed to investigate potentially positive interventions for long COVID-19 symptoms.     

COVID-19 and liver injury in individuals with obesity

Coronavirus disease 2019 is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 that manifests as a variety of clinical manifestations, including liver damage commonly detected by a hepatocellular pattern from liver function tests. Liver injury is associated with a worse prognosis overall. Conditions associated with the severity of the disease include obesity and cardiometabolic comorbidities, which are also associated with nonalcoholic fatty liver disease (NAFLD). The presence of NAFLD, similarly to obesity, is associated with an unfavourable impact on the coronavirus disease 2019 outcome. Individuals with these conditions could present with liver damage and elevated liver function tests due to direct viral cytotoxicity, systemic inflammation, ischemic or hypoxic liver damage or drug side effects. However, liver damage in the setting of NAFLD could also be attributed to a pre-existing chronic low-grade inflammation associated with surplus and dysfunctional adipose tissue in these individuals. Here we investigate the hypothesis that a pre-existing inflammatory status is exacerbated after severe acute respiratory syndrome coronavirus 2 infection, which embodies a second hit to the underestimated liver damage.