METAVIRscore

METAVIR score is a histopathological scoring system used to quantify liver fibrosis and inflammatory activity in chronic liver diseases, most prominently hepatitis C. It provides a two-part assessment on liver biopsy specimens: fibrosis, graded from F0 to F4, and inflammatory activity, graded from A0 to A3. The system is widely used in clinical practice and research to stage disease, monitor progression or regression, and evaluate response to therapy.

Fibrosis is staged as follows: F0 indicates no fibrosis; F1 denotes portal fibrosis without septa; F2 indicates portal fibrosis with few septa; F3 corresponds to numerous septa without cirrhosis; and F4 represents cirrhosis. Inflammation activity is categorized as A0 for no activity, A1 for mild activity, A2 for moderate activity, and A3 for severe activity. The combined F and A scores allow clinicians and researchers to describe both structural scarring of the liver and the degree of ongoing inflammatory damage.

The METAVIR score was developed in the mid-1990s by Bedossa, Poynard, and colleagues and has since become a standard tool, especially in hepatitis C trials, to assess fibrosis stage and treatment-induced changes. It is also used in other chronic liver diseases, though some etiologies may be evaluated with alternative scoring systems. Limitations include sampling variability inherent to liver biopsy and inter-observer differences in interpretation; METAVIR may be less applicable for certain diseases where fibrosis patterns differ from those commonly observed in hepatitis C.

See also: liver biopsy, hepatic fibrosis, chronic hepatitis C, other histological scoring systems.