Prospective Comparison of Fibroscan, King's Score and Liver Biopsy for the Assessment of Cirrhosis in Chronic Hepatitis C Infection
Posted: 02/07/2011; J Viral Hepat.
"Historically, liver biopsy (LB) was the sole method to evaluate the severity of hepatic fibrosis in patients with chronic hepatitis C infection. However, LB is expensive and associated with a risk of severe complications. Therefore, noninvasive tests have been developed to assess the severity of liver fibrosis. The accuracy of Fibroscan (FS) and King's score (KS) was evaluated individually and in combination using liver histology as the reference standard. One hundred and eighty-seven patients were identified who had undergone a biopsy with a diagnosis of chronic hepatitis C virus (HCV) mono-infection (HCV RNA-positive by RT-PCR), attending King's College Hospital (n = 88) or the Royal Free Hospital (n = 99) (London) between May 2006 and December 2007. Liver fibrosis was scored using the Ishak method; significant fibrosis was defined as Ishak fibrosis stage F3–F6, and cirrhosis defined as Ishak fibrosis F5–F6. The diagnostic accuracy of each test was assessed by area under receiver operator characteristic curves (AUROC). Median age was 49 years (43–54) and 115 (61%) were male. The AUROC for FS, KS and FS + KS for the diagnosis of Ishak F3–F6 were 0.83, 0.82 and 0.85, respectively and for the diagnosis of cirrhosis (≥F5) were 0.96, 0.89 and 0.93, respectively. The negative predictive values for the diagnosis of cirrhosis using the optimal cut-off results for fibrsocan (10.05 kPa), KS (24.3) and the two combined (26.1) were 98%, 91% and 94%, respectively. The noninvasive markers and, particularly, FS were effective tests for the prediction of cirrhosis in chronic hepatitis C. Both KS and FS also had clinical utility for the prediction of Ishak fibrosis stages F3–F6...."
"....In summary, FS and KS have clinical utility in identifying patients with significant fibrosis and cirrhosis. For the lower stages of fibrosis (≤F2), the combination of FS + KS had the best AUROC curve, but it was not statistically different to FS or KS alone. FS alone was the best test for predicting ≥F3 fibrosis. FS measures liver stiffness and not fibrosis, and thus factors that cause inflammation or add to oedema may elevate FS readings. All tests perform better at the more severe scale of fibrosis, and overall FS is a superior test, but in circumstances where FS is not available, KS is a suitable alternative..."
There seems to be some confusion about fibrosis and the questions you are asking.
If a biopsy was already done ("Should one have that done as a baseline, even if a liver biopsy was just done?") there is no need to repeat measurement of fibrosis obtained by biopsy except maybe every 5 years. Liver disease is a slow progressive disease. So if you are not stage 3 or 4 now you can easily wait for the newer classes of DAA meds that will be coming to market in the next few years.
("What test or tests are considered "best of class"?" ) I am not aware of any insurance company or liver transplant center in the U.S. that is using anything other then biopsy to assess the degree of liver fibrosis. Biopsy is still the "gold standard" for assessing the degree of liver fibrosis.
An ultrasound is not used to assess liver fibrosis. When cirrhosis is extensive the nodular structure of the liver can be detected as well as other complications of cirrhosis. But an ultrasound or for that matter a CT scan is not used for assessing fibrosis.