IMMUNOHISTOCHEMICAL CHARACTERIZATION OF HEPATIC EOSINOPHIL CATIONIC PROTEIN IN PRIMARY BILIARY-CIRRHOSIS

We have previously reported that serum eosinophil cationic protein (EC P) levels are increased in primary biliary cirrhosis (PBC). However, l ittle is known about the role of eosinophils in the pathogenesis of th is disease. In this study, liver biopsy specimens obtained from 27 PBC patients (stage I: 11 cases; stage II: 9 cases; stage III: 5 cases; s tage IV: 2 cases) were stained with a monoclonal antibody (EG2) produc ed against ECP in an attempt to elucidate whether EG2-positive eosinop hils are involved in the destruction of bile duct in PBC. Needle liver biopsy specimens obtained from 24 patients with chronic hepatitis C ( CHC) were used as controls. In PBC, more than 10 EG2-positive cells we re noted per portal tract in 6 cases, less than 10 EG2-positive cells in 10 cases and none in 11 cases. In CHC, more than 10 EG2-positive ce lls were detected per portal tract in only one case, less than 10 EG2- positive cells in 3 cases and none in 20 cases. According to the semi- morphometric statistical analysis, the hepatic infiltration rate of EG 2-positive activated eosinophils into the portal tract was significant ly higher in PBC than in CHC. Based on the stages of PBC, the infiltra tion rate of EG2-positive cells was significantly higher in stages I a nd II than in stages III and IV. A significant correlation was found b etween EG2-positive cell infiltration and small round cell infiltratio n. These findings suggest that EG2-positive, activated eosinophils may be involved in the early stages of PBC when the inflammatory changes are localized in the portal tract, It is tentatively speculated that a ctivated eosinophils may play a role possible as effector cells in the immunopathogenesis of PBC.