Chronic liver disease in patients with COVID-19

The global outbreak of SARS-CoV-2, which later led to the 2019 (COVID-19) pandemic, has killed more than 6.5 million people worldwide.

Although SARS-CoV-2 is a respiratory virus, liver dysfunction has been reported in approximately 50% of infected patients. The manifestation of chronic liver disease (CLD) was common in severely ill COVID-19 patients requiring hospitalization.

Stady: Liver and biliary tract diseases in patients with COVID-19 infection. Image credit: Explode / Shutterstock.com

A higher mortality rate has been associated with COVID-19 patients with cirrhosis. newly Gastroenterology Clinics in the North The study summarizes the clinical outcomes of COVID-19 patients with CLD.

Prevalence of liver impairment in COVID-19

Elevated liver enzyme levels were observed in approximately 83% of COVID-19 patients who required hospitalization. Of all the liver enzymes, an elevated aspartate transaminase (AST) level was most commonly observed in this group of patients.

Increased levels of bilirubin, glutamyl transferase (GGT), and alkaline phosphatase (ALP) have been reported in 3-23%, 13-54%, and 1-22% of COVID-19 patients, respectively. Importantly, one of the main signs of COVID-19 severity is hypoalbuminemia.

The pattern of liver injury associated with SARS-CoV-2 infection was primarily hepatocytes rather than cholestasis. In the early stage of infection, a moderate elevation of AST and ALT is observed. In most cases, AST levels were higher than ALT, with these levels significantly increasing according to disease severity.

In most cases, liver biochemical test abnormalities returned to normal levels within two to three weeks without the need for any specific treatment. COVID-19 patients with elevated AST and ALT levels have been associated with higher mortality.

Pregnant women with COVID-19 showed high levels of AST and ALT, which indicates the importance of monitoring this group for hepatic injury. Individuals with a history of advanced liver disease, particularly cirrhosis, had an increased risk of death after infection with SARS-CoV-2.

Causing liver injury in COVID-19

Several potential mechanisms associated with liver injury in COVID-19 patients have been reported. Liver tissues at autopsy reported megaloblastic/sebaceous steatosis, focal necrosis, lobular necrosis, portal inflammation, and portal venous/sinus microthrombosis.

SARS-CoV-2 infects the host cell by binding to the angiotensin converting enzyme 2 (ACE2) receptor. These receptors are found in hepatocytes and bile duct cells, making the liver a potential target for infection.

In addition, SARS-CoV-2 directly targets hepatocytes and destroys epithelial cells of the bile duct. Autopsy samples also indicated SARS-CoV-2 liver swelling.

In severely infected COVID-19 patients, the host immune system releases an excessive amount of inflammatory mediators, such as interleukin-6 (IL-6), IL-10, IL-2 and interferon γ (IFNγ), causing cellular storms, which May lead to severe impairment of liver function. A significant upregulation of type I and II IFN responses has also been observed in severely infected COVID-19 patients.

Some of the therapeutic agents used to treat SARS-CoV-2 infection, such as immunomodulators, corticosteroids, antibiotics, and antiviral agents, can cause liver injury to varying degrees. For example, lopinavir / ritonavir increases the risk of liver injury four times.

In addition, remdesivir, an analog nucleoside inhibitor of viral RNA polymerase, was found to increase hepatic biochemical levels by 23%. COVID-19 patients treated with tocilizumab also showed an elevated transaminase level.

Clinical outcomes for COVID-19 patients with pre-existing CLD

Several large-scale, multicenter, cohort studies revealed that CLD was associated with significantly higher mortality, especially among patients with cirrhosis. Retrospective cohort studies in Hong Kong and China revealed that hepatitis B virus (HBV) infection was not associated with deaths from COVID-19.

Autoimmune hepatitis (AIH) is a rare finding after COVID-19. Data from multiple studies showed that AIH patients were not at increased risk of adverse clinical outcomes following SARS-CoV-2 infection. Similarly, alcohol-related liver disease (ALD) has been reported to be an independent risk factor for death in CLD patients with COVID-19.

Liver transplant patients are at risk of contracting COVID-19; However, their mortality was significantly lower and matched the results of the general population.

Impact of COVID-19 vaccines on patients with chronic lung disease and liver transplant patients

Adult CLD patients, especially those with cirrhosis and liver transplant recipients, are highly recommended to receive the COVID-19 vaccine. Compared with unvaccinated CLD patients, vaccinated patients was associated with a 64.8% lower risk of SARS-CoV-2 infection. CLD vaccinated patients were also protected from severe infection.

Some patients with cirrhosis have experienced spread of COVID-19 infection after full or partial vaccination. However, this infection has been associated with lower mortality compared to unvaccinated CLD patients.

Most CLD patients and liver transplant recipients show favorable clinical outcomes after vaccination against COVID-19. A lower serological response to immunization was found in elderly patients who were on anti-metabolic drugs and B-cell depletion therapies.

Originally published at San Jose News Bulletin