Liver biopsy (LB) was considered to be the best method to evaluate the severity of fibrosis in patients with chronic hepatitis. Over time, it was demonstrated that LB is not really a "gold standard" because of its intra- and interobserver variability, the sampling variability and, last, but not least, the fact that it is an invasive method, with morbidity and mortality greater than zero. Considering all these facts, noninvasive methods for the evaluation of liver fibrosis were developed in the last few years (especially transient elastography and FibroTest – ActiTest), in order to replace the LB.
The research team led by Prof. Sporea from The University of Medicine and Pharmacy Timisoara, Romania, Dept. of Gastroenterology and Hepatology, compared the noninvasive evaluation of patients with chronic viral C hepatitis by means of transient elastography to the "gold-standard" of evaluation–LB. This will be published on November 14, 2008 in the World Journal of Gastroenterology.
Transient elastography is an ultrasound-based, non-invasive method, which measures the liver stiffness by means of a FibroScan® device (EchoSens, Paris, France). By using an ultrasound transducer probe mounted on the axis of a vibrator, the transmission of low-frequency vibrations from the right intercostal space creates an elastic shear wave that propagates into the liver. A pulse-echo ultrasound acquisition is then used to detect the velocity of wave propagation. This velocity is proportional to the tissue stiffness, with faster wave progression occurring through stiffer material. Measurement of liver stiffness is then performed and measured in kPa.
Transient elastographic assessment of LS was validated as method of evaluation in chronic hepatitis C. Also, there are some articles that proved the value of this method in other chronic hepatopathies [like hepatitis B virus (HBV) infection, haemochromatosis, primary billiary cirrhosis or non-alcoholic steato-hepatitis], due to fibrosis, measured by transient elastography, was compared to the LB.
In patients with chronic hepatitis C virus (HCV) hepatitis, when compared to the LB, considered to be the "gold standard", transient elastography can differentiate between significant fibrosis and absent or mild fibrosis. According to international guidelines, only patients with significant fibrosis (F≥2 Metavir), should receive antiviral therapy. A cut-off value for liver stiffness, with a good positive predictive value, was established in order to differentiate patients with significant fibrosis (who should be treated) from those with and absent or mild fibrosis (who do not antiviral need treatment), so that in patients with chronic HCV hepatitis, liver stiffness measurement could be used for the decision of therapy, in most patients, avoiding LB.
Similar to other anterior studies from different regions of the world, this study demonstrates the value of the non-invasive evaluation of liver stiffness for fibrosis assessment in chronic C viral hepatitis.