Oct. 20, 2022
The ability to monitor disease progression in nonalcoholic fatty liver disease (NAFLD) and understand its impact on liver outcomes remains poorly understood. Although liver biopsy is currently used to diagnose and manage patients with this condition, the search for accurate, less invasive alternatives that enable monitoring of disease severity is ongoing.
A technology developed at Mayo Clinic called magnetic resonance elastography (MRE) combines MRI imaging with low-frequency vibrations. Mayo Clinic hepatologists are now using MRE to measure liver stiffness, an indicator of fibrosis. This noninvasive approach has been shown to provide accurate information. However, it is unclear whether repeat liver stiffness measurement (LSM) by MRE can be used to track longitudinal changes in fibrosis, and whether this test can provide a noninvasive means of predicting future liver-related outcomes and death. To test the effectiveness of MRE in this role, Mayo Clinic researchers conducted a study examining the association between longitudinal changes in LSM and future liver-related outcomes. The results of this study were published in Hepatology in 2022.
Study methods
In this retrospective study, researchers identified 128 adult patients with NAFLD who underwent at least two serial MREs at Mayo Clinic in Rochester, Minnesota. The researchers defined disease progression and regression to include any LSM change of 19% above or below the initial LSM, respectively. They examined the association between change in LSM and liver-related outcomes occurring after the last MRE using time-to-event analysis.
According to Alina M. Allen, M.D., a gastroenterologist at Mayo Clinic in Rochester, Minnesota, and a co-author of the Hepatology article, this study was designed to provide some important information about the role of MRE in the clinical setting.
"This study expands the role of MRE beyond liver fibrosis estimation by adding a predictive feature to improve individualized disease monitoring and patient counseling. In patients without cirrhosis, MRE can guide disease surveillance and timing of longitudinal, noninvasive monitoring in NAFLD. In patients with cirrhosis, MRE can provide an additional method to estimate the severity of their disease, which can be extremely important in patient counseling and in selection of patients for clinical trials."
Results
Dr. Allen and co-authors shared a number of key study findings, including the following:
- NAFLD progression (LSM= +0.61 kPa/year) occurred in 17 patients (13.3%).
- NAFLD regression (-0.40 kPa/year) occurred in 35 patients (27.3%).
- Stable LSM was noted in 76 participants (59.4%).
- Among the 75 participants diagnosed with NAFLD without cirrhosis at baseline, cirrhosis development occurred in 14% of those with LSM progression and 2.9% of those without LSM progression (p = 0.059) over a median 2.7 years of follow-up from the last MRE.
- Among the 29 participants diagnosed with compensated cirrhosis at baseline MRE, decompensation or death occurred in 100% of those with LSM progression and 19% of those without LSM progression (p < 0.001) over a median 2.5 years of follow-up after the last MRE.
Overall, Dr. Allen explains that the study suggests that MRE can provide a unique, individualized prediction of outcomes for each patient with cirrhosis, based on the current LSM. "This approach provides a more granular risk stratification on a scale that is not confined to four histological stages of fibrosis or the dichotomized stratification of high risk versus low risk that is based on predetermined cutoffs of noninvasive serum biomarkers. For example, two patients of similar age and sex, one with LSM of 5 kPa and the other with 8 kPa, should perhaps be managed differently. Although both have cirrhosis, their risk of decompensation or death in the following years differs considerably — 9% versus 20% at 1 year. Therefore, counseling related to therapeutic and preventative interventions should be tailored accordingly."
Dr. Allen notes that the study data should be validated in other cohorts at centers outside of Mayo Clinic and that she and colleagues from Mayo Clinic Radiology are collaborating on additional research. "We plan to expand the study examining the role of MRE to the Olmsted County population in Minnesota, in combination with the risk factors from the rest of their medical histories. We will combine the information from participants' medical histories to determine who is at risk of NAFLD, then use MRE to accurately evaluate their liver health and follow them for several years to validate the ability of these methods to predict who is at risk of cirrhosis and complications, and who is at risk of death from liver disease. There is a huge need to identify this silent disease in the early stages to allow for timely intervention and prevention of end-stage liver disease and death."
For more information
Gidener T, et al. Change in serial liver stiffness measurement by magnetic resonance elastography and outcomes in NAFLD. Hepatology. In press.
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