Effective Diagnostics for Liver Disease Are Urgently Needed
The following article is an opinion piece written by Dr. Tram Tran. The views and opinions expressed in this article are those of the author and do not necessarily reflect the official position of Technology Networks.
Due to the increasing incidence of diabetes, obesity and metabolic disease in the United States, it is estimated that one in four patients has some form of fatty liver disease. The impact of this on the healthcare system has been realized and is likely to increase over time.
随着初级护理医师继续增加easing number of patients with fatty liver disease, it is important for them to be able to effectively triage these patients to ensure the best possible care. For many patients with non-alcoholic fatty liver disease (NAFLD), primary care would focus on diet and exercise to reduce the risk of liver disease progression.
However, many patients with NAFLD have a more severe inflammatory form of fatty liver called non-alcoholic steatohepatitis (NASH) that, if left untreated, could lead to significant complications including cirrhosis, liver cancer or death.
It is therefore important for physicians to diagnose NASH, assess the stage or severity of patients, monitor the progression of liver disease and identify the risk factors to initiate the appropriate intervention.
Many primary care physicians may see patients in the earlier stages of liver disease when symptoms may be mild or non-existent, and therefore they may not recognize the potentially progressive nature of NASH. The hepatologists and specialists that work with late-stage liver disease patients, however, are astutely aware that the rise in NASH cases is lengthening the list of patients who are manifesting severe disease and eventually may need a liver transplant.
According to the results of a 2021 study,1NASH was the second-leading indication for liver transplantation in the U.S. and the fastest rising since 2002. This overall burden to our healthcare system will only continue to grow.
The best way to avoid the progression to late-stage liver disease is through early intervention. However, the ability to effectively evaluate liver disease is limited by the main diagnostic tool: the liver biopsy.
A liver biopsy is a procedure in which a needle is inserted into the liver to remove a small piece for microscopic analysis and diagnosis. As one can imagine, many patients are reluctant to undergo this procedure. It is invasive, carries a risk of bleeding and pain and requires careful consideration of surrounding logistics that go with a procedure – taking time off work, being driven home, etc.
The nature of the liver biopsy presents clinicians with a significant challenge. How can we effectively diagnose, stage and monitor fatty liver disease when patients are reluctant to routinely undergo the procedure?
From this, broader questions begin to emerge. How can you effectively triage patients towards the appropriate treatment path? How can you monitor a patient’s response to treatment?
Fortunately, these types of questions are being asked by many experts in the field.
Researchers have recently focused on measuring the properties of active liver disease biology, which is thought to be more advantageous than studying a single biopsy sample from the diseased liver. This is because the liver injury may be heterogeneous and patchy in nature, and a small sampling of the liver (approximately 1/50,000th) of the organ – as collected from a biopsy – might not accurately reflect the degree of damage. A dynamic biological measurement would give a more systemic snapshot of the disease state.
At the most recent American Association for the Study of Liver Diseases (AASLD) conference, Dr. Arun Sanyal (Virginia Commonwealth University), in collaboration with Glympse scientists, presented data demonstrating the high accuracy (AUC 0.97) of a biosensor blood test assay in predicting NASH vs healthy patients.2We achieved this by measuring protein enzymatic activity–a fundamental biopathology of NASH.
The activity of certain proteases, or enzymes that are involved in the cleavage of proteins, varies depending on the disease state within the liver. By exposing these proteases to a selection of small protein fragments (peptides), we can measure this activity. Furthermore, because liver proteases circulate in the bloodstream, we can measure this from a routine blood test sample.
We are on the cutting edge of understanding biomarkers in this field, driven by the promise of what this data could mean for the patients in need.
Additionally, the NIMBLE group gave another important presentation at the AASLD conference. NIMBLE (Non-Invasive Biomarkers of Metabolic Liver Disease) is a joint effort between industry, academia and government. The group presented important data evaluating the performance of five different non-invasive tests with the goal of reducing the need for liver biopsy in this patient population, hopefully setting the stage for clinical biomarker use in the future.3
Any non-invasive, accurate diagnostic would have significant implications for patients. Not only would a simple blood test improve both the patient experience and the ability for clinicians to monitor disease progression, but it would also improve access to investigational NASH and NAFLD treatments in clinical trials as investigators could better determine the right patients for studies.
Having a reliable tool for liver disease diagnosis would ensure that patients are able to access these investigational medicines in a timely manner, leading the field towards better therapeutics and intervention before the most severe outcomes, like liver transplants, are needed.
For everyone involved in liver disease biomarker research, our overarching goal is to optimize the best practices for patient care. We, of course, recognize the urgent need for the healthcare system to more effectively triage liver disease patients as the need for liver transplants continues to significantly outpace available donor organs.
At the heart of this research, however, is the individual patient and the need to effectively diagnose, monitor and prevent liver disease progression. The research being conducted at Glympse and elsewhere offers hope that this need will soon be met.
References
1. Younossi, ZM et al. Nonalcoholic steatohepatitis is the most rapidly increasing indication for liver transplantation in the United States.Clin. Gastroenterol.Hepatol. 2021; 19:580–589. doi:10.1016/j.cgh.2020.05.064
2. Sanyal, Arun. Accurate diagnosis of NASH using novel protease based liquid biopsy. Glympse at AASLD 2021. Nov. 2021.https://glympsebio.com/presentation-accurate-diagnosis-of-nash-using-novel-protease/. Accessed January 2022.
3. Sanyal A, et. al. Primary results of the NIMBLE stage 1-NASH CRN study of circulating biomarkers for nonalcoholic steatohepatitis and its activity and fibrosis stage. AASLD Meeting Abstract. Nov. 2021.https://fnih.org/sites/default/files/2021-11/CWS_NIMBLE_Abstract.pdf. Accessed January 2022.
About the author
Tram Tran, M.D. is the Chief Medical Officer of Glympse. She is a renowned liver and viral specialist with over 20 years of academic and industry experience as a physician-scientist. Prior to Glympse, Dr. Tran worked at Gilead Sciences and, before that, at the Cedars-Sinai Medical Center. She has authored and co-authored over 150 abstracts, published manuscripts and book chapters, and has been extensively involved in clinical trials and National Institutes of Health (NIH) funded research. Dr. Tran earned her M.D. from New York Medical College.
