04. EDITORIAL CRESPO

patitis in our setting. The magnitude of the health and social problem posed by this infection is enormous, as it entails a reduction of life expectancy in these patients, and results in high social and financial costs when progressing to advanced disease stages. Current therapy in relation to chronic hepatits C (CHC) is based on a combination of pegylated interferon alpha (PEG-IFN) and ribavirin (RBV) for a period of 12 months in patients with a 1 or 4 genotype, or for 6 months in subjects infected by genotype 2 or 3. Using this therapy regimen a sustained virologic response is seen in 45-55% of patients with genotype 1, in nearly 65-70% of subjects with genotype 4, and in 75-90% of patients with genotype 2 or 3 (1-3). This noticeable improvement in antiviral therapy efficacy does not exclude that a knowledge of fibrosis stage is still surely valuable to establish a prognosis and the need for antiviral therapy. Liver biopsy is still the gold standard for liver fibrosis staging. In order to reduce intraand inter-observer variability, numerous liver damage (including of course fibrosis) quantitation systems have been developed, including Knodell index (4), a modification thereof by Ishak et al. (5), and the METAVIR score (6). Despite the valuable teachings of liver biopsy in the field of Hepatology, and despite its unquestionable diagnostic capability, this technique has a number of limitations, including: a) a relatively high probability of sampling error (may preclude a cirrhosis diagnosis in up to 15-20% of cases); b) a relatively small sample size reducing the technique’s sensitivity in the diagnosis of advanced fibrosis; in fact, fibrosis is usually underestimated in small-size samples; c) non-negligible morbidity and mortality, and poor patient acceptance, especially if a second test is required; d) a high economic cost, as it requires admission for a few hours; and e) and a snapshot when fibrosis is a clearly dynamic process. An ideal diagnostic technique to quantitate liver fibrosis should be user-friendly, inexpensive, safe, free of side effects, specific, sensitive, reproducible, independent of metabolic changes, easy to perform, non-influencible by biliary or urinary clearance, and fit to reflect fibrosis regardless of cause. With this goal in mind, various fibrosis models have been developed in recent years based on relatively simple serologic measurements, which have proven useful to assess liver fibrosis extent in patients with chronic hepatitis C, even though they obviously do not meet all the aforementioned characteristics. These fibrosis-predicting models may be clustered in 3 types: a) models using indirect markers for liver fibrosis; b) models using direct markers for liver fibrosis; and c) models combining indirect markers with insulinresistance tests. In this issue Romera et al. (7) validate the prognostic Sydney fibrosis score in patients with hepatitis C, and note that including insulin resistance in the predicThe art of predicting fibrosis in hepatitis C 1130-0108/2006/98/3/153-160 REVISTA ESPAÑOLA DE ENFERMEDADES DIGESTIVAS Copyright © 2006 ARÁN EDICIONES, S. L. REV ESP ENFERM DIG (Madrid) Vol. 98, N. ° 3, pp. 153-160, 2006