By Salynn Boyles, Contributing Writer, MedPage
Today
Published: June 03,
2013
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman
School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA,
BSN, RN, Nurse Planner
Action Points
- While liver biopsy remains the gold standard for predicting disease
progression in people with HCV infection, it is no longer recommended as
necessary in all patients before the initiation of antiviral therapy with newer
medications. - This study suggests that blood tests can help to identify HCV-infected
patients with clinically significant fibrosis, with somewhat greater accuracy
for identifying cirrhosis than for less advanced
fibrosis.
Blood testing can accurately identify clinically significant fibrosis and
cirrhosis in people with hepatitis C virus (HCV) infection and may be an
alternative to liver biopsy in some patients, a new study found.
The analysis of 172 studies comparing various blood tests to biopsy in HCV
patients revealed that some of the simplest, cheapest blood tests performed as
well as more expensive, complex tests, reported Roger Chou, MD, and Ngoc Wasson,
MPH, from the Evidence-Based Practice Center at Oregon Health and Science
University in Portland.
Six tests identified clinically meaningful fibrosis with a median positive
likelihood ratio of 5 to 10 at commonly used cutoffs and areas under the
receiver-operating characteristic curve (AUROCs) of 0.70 or greater (range 0.71
to 0.86), they wrote in the June 4 issue of the Annals of Internal
Medicine.
The tests were the platelet count, age-platelet index, aspartate
aminotransferase-platelet ratio index (APRI), FibroIndex, FibroTest, and Forns
index.
In addition, three of those tests, platelet count, age-platelet index, APRI,
plus Hepascore, all identified cirrhosis with median positive likelihood ratios
of 5 to 10 and AUROCs of 0.80 or greater (range 0.80 to 0.91).
"Our results suggest that blood tests can help to identify HCV-infected
patients with clinically significant fibrosis, with somewhat greater accuracy
for identifying cirrhosis than for less advanced fibrosis," the researchers
wrote.
Liver biopsy remains the gold standard for predicting disease progression in
people with HCV infection, but it is no longer recommended in all patients
before the initiation of antiviral therapy. Drawbacks of liver biopsy include
the potential for sampling error and risk for complications such as bleeding,
severe pain, and infection,
Blood tests have been proposed as a less invasive alternative to liver
biopsy, and more than two dozen tests have been studied for this purpose.
"We expect to see all-oral, interferon-free HCV treatment regimens in a few
years, and that means many more people are likely to begin antiviral therapies,"
they wrote. "Having blood tests to help identify patients who can benefit from
these treatments will be increasingly important."
Using MEDLINE, the Cochrane Library database, and other reference lists, the
authors identified studies that compared blood tests to liver biopsy for
diagnosing fibrosis or cirrhosis in HCV-infected people.
Most of the studies included in the analysis were conducted in the U.S.,
Europe, Asia and northern Africa, and 15 were rated as good quality studies,
while five were rated poor quality. The remainder were considered fair
quality.
Chou said one of the most surprising findings was that the simple APRI blood
test performed as well or better than more complex and expensive tests.
"This test provided useful information about the severity of underlying liver
disease," he told MedPage Today. "For patients trying to decide if they
should begin antiviral therapy, this and other blood tests may be an alternative
to biopsy."
In a subanalysis in which APRI was compared to FibroTest (known as FibroSure
in the U.S.), the predictive value of the two tests was very similar, Chou
said.
FibroTest is a patented, six blood serum test for liver damage marketed by
French company BioPredictive.
APRI was associated with a slightly lower AUROC than the FibroTest for
fibrosis (18 studies: median difference, -0.03; range, minus 0.10-0.07), but
there was no difference for cirrhosis (seven studies; median difference, 0.0;
range, minus 0.04 to 0.06).
Chou and Wasson noted several limitations to their analysis, including the
fact that only English-language studies were included and that most trials
failed to describe blinded interpretation of liver biopsy specimens. Many also
included inadequate descriptions of enrollment methods.
The added that the results may not apply to populations excluded from the
review, including patients coinfected with hepatitis B virus, HIV, and those
receiving hemodialysis.
The study was funded by a grant from the Agency for Healthcare Research and
Quality.
Primary source: Annals of Internal Medicine
Source
reference:
Chou R, et al "Blood tests to diagnose fibrosis or cirrhosis in
patients with chronic hepatitis c virus infection" Ann Intern Med 2013;
158.