Latin American Association for the Study of the Liver recommendations on treatment of hepatitis C

2014 Annals of Hepatology 13 Suppl 2 (s4-66)

Methods for staging liver disease in chronic hepatitis C
Mechanical noninvasive methods
The four mechanical methods currently available are: transient elastography (liver assessed by FibroScan, acoustic radiation force elastography (ARFI), shear wave elastography (SWE) and MRI elastography. FibroScan, ARFI and SWE have in common the fact that they are unable to discriminate between intermediate stages of fibrosis, their best application being for the diagnostic of cirrhosis and advanced fibrosis (F3, F4).
Of the four methods mentioned, transient elastography (liver assessed by FibroScan) is the one associated with the greatest number of publications, especially in chronic hepatitis C, and accordingly is the most validated and standardized for almost all liver diseases. It can be performed at bedside with a rapid learning curve, and it has a validated prognostic value in cirrhosis. However, the equipment is expensive, obesity and the presence of ascites are limitations for the procedure, and acute hepatitis, extra hepatic cholestasis, and congestion can lead to false positive results.
ARFI and SWE are more recent and very promising methodologies, associated with the propagation of acoustic waves. In a recent meta-analysis, ARFI gave results comparable to FibroScan for the diagnostic of cirrhosis and advanced fibrosis, and SWE can have a superior performance for significant fibrosis (>=F2). Despite this potential, these two methods, compared with FibroScan, still need better standardization and better knowledge of the confounding factors, and have a longer learning curves.

Biochemical (biomarkers) and combined method
Several biochemical tests have been investigated in hepatitis C in an attempt to evaluate the staging of chronic hepatitis C. Among these, the most validated are undoubtedly the noncommercial APRI (AST-to-platelet ratio index) and FIB4 (AST, ALT, age and platelets) and the patented FibroTest and FibroMeter. FibroMeter, and especially FibroTest, have been extensively used in France and other countries, and are validated for use in various liver diseases. These two tests are patented and must be performed in laboratories that meet certain quality standards, and thus are more expensive and less readily available than other tests. [...]
To increase the sensitivity and specificity of noninvasive methods, attempts have been made to combine methods. The first successful combination was FibroTest with APRI (SAFE-biopsy) for the diagnosis of both cirrhosis and a significant biopsy. Alternatively FibroMeter, FibroTest and APRI can be combined with elastography using FibroScan in diagnostic algorithms. With the use of these algorithms, there is an important reduction in the need for liver biopsy, and a high percentage of cases can be correctly classified.

RECOMMENDATIONS
- Whenever possible, use noninvasive methods. Liver biopsy in the staging of hepatitis C is reserved for cases of clinical suspicion of association with other liver disease, cases of disagreement between the results of noninvasive methods, or cases where the use of indirect methods is clinically or technically impossible (Class 1, Level A).
- The assessment of advanced liver fibrosis (F3, F4 of METAVIR classification) and cirrhosis (F4) in patients with chronic hepatitis C can be made indirectly by mechanical methods, preferably by elastography by FibroScan (Class 1, Level B).
- The highest accuracy and greatest reduction in the need for liver biopsy is achieved with the combination of two biomarkers or with the combination of a biomarker with a mechanical method (Class 1, Level B).
- In the setting of low-income countries, the combination of a low and high cutoff level for the APRI and FIB4 levels can be indicated (recommendation 2B) but a significant number of patients will not be properly classified (outside the cutoff values).

Pubmed : 25185535