The use of non-invasive tests provides similar prognostic accuracy compared to histology for adverse outcomes in patients with non-alcoholic fatty liver disease (NAFLD), according to a new study by a UK and European research group.
Published in the The Lancet Gastroenterology and Hepatology, the study used an individual participant data meta-analysis approach to compare the prognostic performance of liver histology for adverse clinical outcomes in adult patients with NAFLD with three non-invasive methods.
The three comparative tests were liver stiffness measurements by vibration-controlled transient elastography (LSM-VCTE), the fibrosis-4 index (FIB-4),and the NAFLD fibrosis score (NFS). The prognostic performance of the index tests was compared using the time-dependent area under the curve (tAUC). The team set the primary outcome as a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation or cirrhosis complications.
Non-invasive tests performance
A total of 65 eligible studies, made up of 2,518 patients with biopsy-proven NAFLD and a mean age of 54 years (44.7% female), were analysed. Participants were followed for a median of 57 months and the composite endpoint occurred in 5.8% of patients.
At five years, the tAUC was 0.72 (95% CI 0.62 – 0.81) for histology, 0.76 (0.70 – 0.83) for LSM-VCTE, 0.74 (0.64 – 0.82) for FIB-4 and 0.70 (0.63 – 0.80) for NFS. However, pairwise differences were not significant.
Also at five years, there were similar sensitivities and specificities for histologically diagnosed cirrhosis and the three non-invasive markers. For example, histology had a cumulative sensitivity of 33.3% and a specificity of 90.5% and LSM-VCTE a sensitivity of 29.4% and a specificity of 92%.
The authors concluded that given how the non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD, the tests could be considered as alternatives to liver biopsy in some cases.
NAFLD in context
The global prevalence of NAFLD is estimated at 24%, and it poses a high risk of liver-related morbidity and mortality. This is largely due to, and from, extra-hepatic cancer and cirrhosis.
While it is recognised that more severe fibrosis – that is stages F3 and F4 – is associated with increased risks of liver-related complications and death, fibrosis staging can only be evaluated with a liver biopsy.
Although several non-invasive biomarkers exist and show good diagnostic accuracy, the prognostic value of these non-invasive tests in comparison to liver histology has not previously been assessed.
