Professor Darrell Crawford
Director of Research, Gallipoli Medical Research
The subject of my research higher degree thesis (MD) completed in 1994 was malnutrition in liver disease. Malnutrition is a common complication of advanced liver disease and has an adverse effect on outcomes before and after liver transplantation. Little did I realise at that time that 30 years hence, the problem of nutrition in liver disease would not be under nutrition – rather it would be overnutrition!
The epidemic of fatty liver disease (or MAFLD) is truly upon us, evidenced by 30% of the Australian population over 50 years of age affected by this condition. Its greatest predictor is being overweight, and it is associated with sedentary lifestyles and the consumption of high quantities of ultra processed foods. A worrying complication is that a proportion of affected people will develop progressive liver disease resulting in liver failure, liver cancer and ultimately death or need for liver transplantation. Indeed, MAFLD is quickly becoming the most common indication for liver transplantation and the most common underlying liver disease leading to liver cancer.
I am sure that community awareness of MAFLD is poor – despite the very high prevalence of the condition. I am told that a recent patient told his doctor that he didn’t really need to worry about his liver health because if he blew one liver, he had another one that would take over!
If this reflects community awareness about liver disease, then we are in for a torrid ride. Indeed, liver health takes a back seat in health promotion compared to cardiovascular disease and chronic lung disease. This lack of community awareness is made more stark by the fact that prevention of liver disease is possible. A healthy lifestyle is the key to prevention. Dietary changes, regular exercise and weight loss are at the core of treatment.
The absence of high community awareness means we can safely conclude that fatty liver disease is grossly underdiagnosed and an individual’s disease severity is often underappreciated. Access to current testing methods such as specific blood tests or radiological-based methods is compromised by expense (they are not reimbursed by Medicare) and lack of availability—particularly for rural communities as well as other disadvantaged populations—in whom the prevalence of liver disease is often higher. The current testing paradigm is not fit for purpose given the scale of the problem and is simply not working. In the absence of any significant development or paradigm shift, it is highly unlikely that any impact will be made on the estimated 85% increase in liver related deaths due to MAFLD over the coming decade.
Australia needs a new kind of test, one that is easily accessible in the community and can accurately screen for the extent of liver injury. The optimal pathway to increase detection of liver scarring needs to begin by offering a non-invasive, low cost and highly scalable solution with a community-based, self-administered first line test—not unlike a COVID RAT kit. In addition to accuracy, the community test must be easy to collect, simple to measure, and available to people across all locations and income levels.
This is why we have explored utility of a saliva-based test to diagnose liver fibrosis. Saliva collection is simple, safe and enables community testing in clinics, primary care, and outreach programs. We have measured three proteins involved in liver fibrosis in 205 human saliva samples collected in a secondary care clinic and have developed a score based on the measurement of these proteins that predicts whether an individual has liver fibrosis. This is a world first saliva-based algorithm for the diagnosis of liver fibrosis, and our ultimate aim is to develop a RAT-like test for liver fibrosis for point of care and community testing. This will overcome many of the barriers to diagnosis of liver disease and with increased community awareness we will be able to accept the challenge of reducing mortality from liver disease over the next decade.
