Simplifying access to antivirals for hepatitis C patients may be possible with serum tests of fibrosis such as FIB-4 that can exclude cirrhosis in settings without access to transient elastography, Australian research shows.
Dr Lauren Burrage, a registrar, and colleagues at the Sunshine Coast University Hospital have shown the FIB-4 test, at a cut-off of <0.93, to be “highly efficient” at ruling out cirrhosis in patients prior to commencing treatment for hepatitis C.
The observational study of 793 patients, managed in either a specialist-led hepatology clinic, a nurse-led community based clinic or in prison, found FIB-4 had a higher negative predictive value than the AST/platelet ratio (APRI).
Current Australian guidelines recommend APRI, along with other serum biomarkers such as Hepascore, FibroGENE and the Enhanced Liver Fibrosis (ELF) test but not FIB-4, to exclude cirrhosis in settings where transient elastography is not readily available.
The European Association for the Study of the Liver (EASL) recommends either FIB-4 or APRI where elastography is unavailable, usually outside specialist settings.
The Queensland study compared the performance of APRI scores <1.0 and FIB-4, using the newly described cut-off of 0.93 to exclude cirrhosis.
It found the negative predictive value (NPV) of APRI was 80% in secondary care compared to a 97% with FIB-4. APRI would misclassify 14% of patients with cirrhosis as non-cirrhotic compared to 1% with FIB-4.
However the performance of the tests was closer in other settings.
APRI had a 93% NPV in primary care and 96% in prison compared to 97% and 100% respectively with FIB-4. APRI would misclassify 5% of cirrhotic patients compared to 1% with FIB-4.
The study authors said the consequences of missing patients with cirrhosis was concerning.
“Firstly, failure to identify cirrhosis means that cirrhotic patients would not be able to benefit from HCC and variceal surveillance, and secondly, 8 week DAA regimens that are suitable for non-cirrhotic patients may be inappropriately prescribed and result in less than optimal SVR rates.”
“Our findings validate those of Kelly et al and we suggest that future Australian guidelines should reflect this finding, especially as the cut-off has been validated in the target population,” they wrote in the Internal Medicine Journal.
Dr Burrage told the limbic the tests could reduce the number of patients having to undergo elastography.
“We’ve suggested that the FIB-4 cut off of 0.93 performs better than the APRI score of <1 so maybe that could be used more at some point in the future if it continues to be validated,” she said.
The study concluded: “These findings are particularly relevant to efforts towards HCV elimination as our results are derived from a large group of patients with HCV assessed in primary care and prison and suggests that treatment algorithms in these settings can be simplified.”
This allows easier access to HCV treatment in resource constrained health systems that do not have easy access to transient elastography.”