COVID-19, caused by SARS-CoV-2, is a systemic illness affecting various organs, primarily the respiratory system. Liver involvement is also a recognized aspect. This article explains “COVID liver” and how the virus influences liver health.
How COVID-19 Affects the Liver
COVID-19 can lead to liver injury through several mechanisms. The SARS-CoV-2 virus directly affects liver cells, particularly bile duct cells (cholangiocytes), which express high levels of the angiotensin-converting enzyme 2 (ACE2) receptor, the gateway for viral entry. Although hepatocytes, the main liver cells, have lower ACE2 expression, viral RNA has been detected in liver tissue of COVID-19 patients, suggesting direct viral activity.
Beyond direct viral effects, the body’s immune response to COVID-19 can contribute to liver injury. A widespread inflammatory response, sometimes called a “cytokine storm,” involves an uncontrolled release of pro-inflammatory molecules that can damage organs. Systemic inflammation can lead to liver dysfunction and, in severe instances, hepatic failure.
Indirect effects also play a role. Patients with severe respiratory distress or pneumonia may develop hypoxia, causing hypoxic liver injury. Medications used to treat COVID-19 can induce liver injury as a side effect. Pre-existing liver conditions can be exacerbated, leading to more severe outcomes.
Recognizing Liver Involvement
Liver involvement often manifests through blood test changes, rather than prominent outward symptoms. Common indicators include elevated liver enzymes like alanine aminotransferase (ALT) and aspartate aminotransferase (AST). These enzymes are released into the bloodstream when liver cells are damaged, providing a measurable sign of injury.
Other markers like GGT and LDH may also be elevated. While alkaline phosphatase (ALP) and bilirubin levels can rise, they are less common than transaminase increases and are usually mild. Jaundice, a yellowing of the skin or eyes due to high bilirubin, is a less frequent symptom.
Patients might experience general symptoms like fatigue, nausea, or abdominal discomfort, though these are not specific to liver involvement. Diagnosis is primarily through blood tests, routinely monitored in hospitalized COVID-19 patients. Liver enzyme elevation can correlate with infection severity, with higher levels seen in more severe cases.
Managing Liver Effects
Management of liver issues in COVID-19 patients primarily involves supportive care. This means addressing the overall infection, as liver abnormalities often improve with illness resolution. Close and regular monitoring of liver function tests (ALT, AST, and bilirubin levels) is standard practice for hospitalized patients.
If drug-induced liver injury is suspected from COVID-19 medications, providers may adjust dosages or discontinue implicated drugs, weighing benefits against risks. Specific antiviral treatments solely for the liver are not required, as liver injury is a transient consequence of the broader infection. For individuals with pre-existing liver diseases (e.g., cirrhosis or non-alcoholic fatty liver disease), management requires particular attention and a tailored approach.
Long-Term Liver Health After COVID-19
For most individuals, liver enzyme elevations associated with acute COVID-19 are mild and resolve upon recovery. However, some may experience persistent, mild liver enzyme elevations long-term, a phenomenon sometimes observed in “long COVID” or post-COVID conditions. Studies indicate elevated ALT and AST levels can persist for several months after initial infection, especially in those hospitalized.
While severe, chronic liver disease directly caused by COVID-19 is uncommon in otherwise healthy individuals, ongoing research explores its long-term impact on liver health. Some reports suggest links to liver steatosis or worsening of MAFLD in the post-COVID period. Individuals with pre-existing liver conditions or severe COVID-19 warrant continued monitoring after recovery.