ActiTest Score Test

The ActiTest score estimates how much active inflammation is occurring in the liver. Inflammation refers to the immune system’s response to injury or infection, and in the liver this often appears as swelling and damage to liver cells. Over time, repeated or uncontrolled inflammation can lead to scarring (fibrosis) and eventually cirrhosis, which is advanced, irreversible liver disease.

Instead of relying on a liver biopsy, which involves inserting a needle to remove a small piece of liver tissue, the ActiTest uses a combination of standard blood markers, alpha-2-macroglobulin, apolipoprotein A1, haptoglobin, bilirubin, gamma-glutamyltransferase (GGT), and alanine aminotransferase (ALT), along with a person’s age and sex. Each of these proteins or enzymes reflects different aspects of liver health. For example, ALT and GGT rise when liver cells are damaged, while haptoglobin and alpha-2-macroglobulin change in response to inflammation. When combined into a single algorithm, these markers produce a score between 0 and 1 that corresponds to grades of liver activity on the METAVIR scale, a system commonly used by pathologists to grade liver biopsies. Higher scores indicate more severe inflammation.

The ActiTest score has been validated in chronic hepatitis B and C as well as in non-alcoholic fatty liver disease (NAFLD). Studies show it performs reasonably well compared to biopsy, with good accuracy for detecting moderate to severe inflammation. In patients with severe obesity and fatty liver, it has shown strong ability to identify steatohepatitis, the more harmful form of fatty liver disease. While not perfect, it often spares patients the risks of biopsy.

That said, the test has limitations. Conditions such as obesity, metabolic syndrome, or generalized inflammation outside the liver may influence the markers used. Discordance with biopsy results can occur, though this is often due to sampling error from the biopsy itself rather than the test. For best use, clinicians often pair ActiTest score with FibroTest score, which estimates liver fibrosis, to get a more complete picture of both current activity and long-term damage.

Overall, the ActiTest score provides a practical, reproducible way to monitor liver health over time. When interpreted in the right clinical context, it helps guide treatment decisions, assess disease progression, and reduce reliance on invasive procedures.