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

Spectrum of COVID-19 induced liver injury: A review report

The coronavirus disease 2019 (COVID-19) pandemic has caused changes in the global health system, causing significant setbacks in healthcare systems worldwide. This pandemic has also shown resilience, flexibility, and creativity in reacting to the tragedy. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection targets most of the respiratory tract, resulting in a severe sickness called acute respiratory distress syndrome that may be fatal in some individuals. Although the lung is the primary organ targeted by COVID-19 viruses, the clinical aspect of the disease is varied and ranges from asymptomatic to respiratory failure. However, due to an unorganized immune response and several affected mechanisms, the liver may also experience liver cell injury, ischemic liver dysfunction, and drug-induced liver injury, which can result in respiratory failure because of the immune system's disordered response and other compromised processes that can end in multisystem organ failure. Patients with liver cirrhosis or those who have impaired immune systems may be more likely than other groups to experience worse results from the SARS-CoV-2 infection. We thus intend to examine the pathogenesis, current therapy, and consequences of liver damage concerning COVID-19.

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

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

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.

Statin Use in Relation to COVID-19 and Other Respiratory Infections: Muscle and Other Considerations

Statins have been widely advocated for use in COVID-19 based on large favorable observational associations buttressed by theoretical expected benefits. However, past favorable associations of statins to pre-COVID-19 infection outcomes (also buttressed by theoretical benefits) were unsupported in meta-analysis of RCTs, RR = 1.00. Initial RCTs in COVID-19 appear to follow this trajectory. Healthy-user/tolerator effects and indication bias may explain these disparities. Moreover, cholesterol drops in proportion to infection severity, so less severely affected individuals may be selected for statin use, contributing to apparent favorable statin associations to outcomes. Cholesterol transports fat-soluble antioxidants and immune-protective vitamins. Statins impair mitochondrial function in those most reliant on coenzyme Q10 (a mevalonate pathway product also transported on cholesterol)-i.e., those with existing mitochondrial compromise, whom data suggest bear increased risks from both COVID-19 and from statins. Thus, statin risks of adverse outcomes are amplified in those patients at risk of poor COVID-19 outcomes-i.e., those in whom adjunctive statin therapy may most likely be given. High reported rates of rhabdomyolysis in hospitalized COVID-19 patients underscore the notion that statin-related risks as well as benefits must be considered. Advocacy for statins in COVID-19 should be suspended pending clear evidence of RCT benefits, with careful attention to risk modifiers.