New FAP-Index could transform early detection of severe liver disease

Metabolic fatty liver disease often has no symptoms in its early stages but can progress to liver scarring (fibrosis) and eventually to liver cirrhosis and liver failure. Determining which patients are most at risk remains a major clinical challenge. Current first-line blood test risk scores often produce uncertain (‘indeterminate’) results, leading to unnecessary specialist referrals and costly follow up investigations.

In a study published in the Journal of Gastroenterology and Hepatology, the researchers report that the FAP-Index combines a simple blood test measuring fibroblast activation protein (FAP) with routinely collected clinical information to generate a more precise assessment of a patient’s risk of liver scarring. FAP is a biomarker directly involved in the biological process that drives fibrosis.

The team found that adding the FAP-Index to existing first-line blood test risk scores reduced uncertain results by up to 70 percent compared with current screening tools alone.

Ziqi Vincent Wang, a PhD student at the Centenary Institute and the University of Sydney and first author on the study, said the new tool could make a real difference for both patients and clinicians.  

“Fatty liver disease is incredibly common but it’s very difficult to know who has severe liver damage,” Mr Wang said.

“The FAP-Index is designed to be simple, affordable and practical, so it can be used early in primary care to identify patients who genuinely need further investigation.”

Unlike many existing scoring systems that rely on indirect markers of liver injury, the FAP-Index incorporates a protein that plays a direct role in the scarring process. The FAP test itself is straightforward and can become adapted for high-throughput or point-of-care settings, making it suitable for widespread clinical use.

Co-senior authors of the study are Professor Mark Gorrell, Laboratory Head in the Centenary Institute’s Centre for Cancer Innovations and Associate Professor Avik Majumdar, who conducted the majority of the study while at Royal Prince Alfred Hospital and is now at Austin Hospital in Melbourne, Australia.

Professor Gorrell said the timing of the research was particularly important, with new drug treatments for liver disease now emerging.

“With effective therapies becoming available, there is an urgent need for better tools to test patients and more accurately detect advanced fibrosis earlier,” Professor Gorrell said.

“By focusing on a protein central to liver scarring and reducing uncertain results, the FAP-Index has the potential to ease pressure on specialist services while ensuring patients in need receive timely care.”

The scientists say that further studies will support the transition of the FAP-Index into routine clinical practice, with the aim of improving outcomes for the growing number of people living with metabolic fatty liver disease.