PERIBILIARY VASCULAR PLEXUS IN PRIMARY SCLEROSING CHOLANGITIS AND PRIMARY BILIARY-CIRRHOSIS

The peribiliary vascular plexus plays an important role in physiology of bile flow. Disturbance of the microcirculation may contribute to du ctal injury, but little is known about alterations in the vascular sup ply of small bile ducts in liver disease. Immunoperoxidase stains for vascular endothelium (Ulex europaeus, factor Vm-related antigen, CD34) were used to study the peribiliary vascular plexus in 20 cases of pri mary sclerosing cholangitis (PSC) and 27 cases of primary biliary cirr hosis (PBC), two diseases characterized by bile duct destruction. Norm al liver from 10 autopsy cases of sudden cardiac death was used as a c ontrol. Interlobular bile ducts (20- to 80-mu m diameter) were identif ied on AE1/AE3 immunostain; vessels adjacent to the basement membrane of these ducts were counted. Normal interlobular bile ducts had an ave rage of 2.15 vessels per duct (range, 1.68 to 2.71). Few PBC or PSC ca ses had a normal number of peribiliary vessels. There was a trend towa rd vasopenia at higher stage, although vascular loss was noted in earl y stages as well. The pattern of vascular loss was different for the t wo diseases; in PSC, the periductal capillaries were often preserved b ut were pushed away from the basement membrane by concentric deposits of collagen. Small residual vessels could be identified within fibrous scars of obliterated bile ducts in PSC. In 4 stage 3 or 4 PSC cases w ith little bile duct injury, vessel/duct ratio approached normal level s. In PBC, vessels were obliterated in areas of granulomatous inflamma tion and heavy lymphocytic infiltrate around bile ducts. Zn conclusion , loss of peribiliary vessels is common in PSC and PBC. Vessel loss is seen in early stages and may contribute an element of ischemia to con tinued small bile duct loss but is probably secondary to the inflammat ory process. HUM PATHOL 28:791-795. Copyright (C) 1997 by W.B. Saunder s Company.