Noninvasive markers of fibrosis: key concepts for improving accuracy in daily clinical practice.

Noninvasive markers of fibrosis have emerged as an alternative to the staging of fibrosis by means of liver biopsy. Apart from being noninvasive and thus lacking the adverse effects of liver biopsy, they offer some advantages such as reduced risk of sampling error, objectiveness in the interpretation of the result, appropriateness for repeated measurements and lower cost. Many studies have validated different panels of blood markers and imaging/transient elastography for the estimation of fibrosis with acceptable accuracy. Clinical scenarios leading to inacurate or failed estimation must be acknowledged, as well as the fact that performance of blood markers and transient elastography, and their diagnostic cut-off values vary among specific liver diseases. The combination of two blood markers or of a blood marker and transient elastography has been shown to increase accuracy of the estimation. Further, unlike liver biopsy the noninvasive markers of fibrosis are not associated with a ceiling effect after cirrhosis is identified, but can discriminate early from advanced stages of cirrhosis. Longitudinal studies have shown their utility as predictors of complications from portal hypertension and mortality, outperforming liver biopsy. In conclusion, noninvasive markers of fibrosis provide major advantages over liver biopsy. The reported performance of some of the available tests particularly when used in combination make them a reliable tool, very attractive for daily clinical practice.