Study Confirms Accuracy of Transient Elastography in NAFLDSonic Detection of Liver Stiffness Emerges as a Useful Screening and Prognostic Test
Researchers from France and Hong Kong determined that transient elastography (TE), a noninvasive, ultrasonic imaging modality, can be accurately performed in the majority of patients with nonalcoholic fatty liver disease (NAFLD) to exclude advanced fibrosis. Full findings of this study, funded by the Chinese University of Hong Kong, appear in the February issue of Hepatology, a journal published by Wiley-Blackwell on behalf of the American Association for the Study of Liver Diseases.
NAFLD is the most common cause of liver disease worldwide. Determining a prognosis for this condition is difficult, as there are no clear predictors of whether NAFLD will progress to nonalcoholic steatohepatitis (NASH), which can lead to cirrhosis and other complications.
Liver biopsy is the standard for diagnosing NASH and fibrosis, but this procedure can be risky and samples only a small percentage of liver tissue. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health (NIH), biopsy carries a small risk of hemorrhage, puncture of other internal organs, infection, and spread of cancer cells. Transvenous liver biopsy carries an additional risk of adverse reaction to the contrast material.
To meet the urgent need for noninvasive alternatives to liver biopsy, a research team led by Victor de Lédinghen, M.D., Ph.D., conducted an evaluation of the accuracy of TE and biochemical tests for the diagnosis of fibrosis and cirrhosis in NAFLD patients. "Transient elastography by Fibroscan is a non-invasive method for the diagnosis of liver fibrosis…Nevertheless, NAFLD patients are underrepresented in previous validation studies," explains Dr. de Lédinghen. The team also examined liver stiffness in association with hepatic steatosis, inflammation, and obesity, and set out to identify factors associated with discordance between liver stiffness measurements (LSM) and histology.
The research team evaluated 246 patients from two ethnic groups from two hospitals in France and Hong Kong with valid LSM acquisitions and satisfactory liver biopsy specimens. Men who consumed more than 30 g of alcohol per week and women who consumed more than 20 g of alcohol per week were excluded. Patients with secondary causes of hepatic steatosis (e.g. chronic use of systemic corticosteroids), positive hepatitis B surface antigen or anti-hepatitis C virus antibody, or histologic evidence of other concomitant chronic liver diseases were also excluded. Since the aim of transient elastography was to diagnose significant fibrosis and early cirrhosis, patients with clinical and radiological evidence of cirrhosis were excluded.