QUANTITATIVE STUDIES ON LIVER FIBROSIS AND ALPHA-SMOOTH MUSCLE ACTIN EXPRESSION IN HEROIN ABUSERS

Lobular hepatic fibrosis and the presence of myofibroblasts were studi ed in heroin abusers, by quantitative automatic image analysis. Ninete en addicts (DA) and thirteen patients having stopped consumption (exDA ) were compared to a non-addict group (Control). Addicts, all anti-HIV and HBsAg negative, showed increased transaminase levels. Hepatitis C markers were not available, at the time of biopsy. The surface of the centrolobular fibrosis, measured on picrosirius stained slides, was r espectively 1.9 and 3.5 times larger in DA and exDA than in Control (p <0.0001). Immunolabelling with an alpha-smooth muscle actin antibody ( alpha-SMA) revealed stellate cells in a perisinusoidal location, mainl y in areas of matrix thickening in the space of Disse. Morphometric an alysis of alpha-SMA expression showed significant differences between the three groups of patients, p<0.0001 (Control: 198.06+/-5.59 mu m(2) ; DA: 2227.91+/-88.02 mu m(2); exDA: 3469.10+/-154.98 mu m(2). The sur face density of collagen and of alpha-SMA reactivity was also signific antly different between these groups (p<0.0001). These data strongly s uggest that heroin is responsible for an early and progressive centrol obular liver fibrosis, occuring simultaneously with a myofibroblastic response. It might represent a reparative phenomenon arising from a di rect vascular injury, leading to an impairment of blood-hepatocyte exc hange.