title: B7-2 positive cells around interlobular bile ducts in primary biliary cirrhosis and chronic hepatitis C.
abstract: Bile duct damage in patients with chronic hepatitis C (hepatitis-associated bile duct lesion) as well as that in patients with primary biliary cirrhosis (PBC; chronic non-suppurative destructive cholangitis), may be causally related to immunological assaults. Efficient antigen presentation is known to require the provision of a costimulatory signal which is dependent on the CD28 on T cell surfaces, and that at least two molecules, B7-1 and B7-2, work as costimulatory ligands for CD28. In this study, we examined immunohistochemically, the expression of B7-2 in portal tracts of liver biopsy specimens obtained from 75 patients with chronic hepatitis C who had hepatitis-associated bile duct lesions, and from 63 PBC patients with chronic non-suppurative destructive cholangitis. B7-2 positive cells were recognizable as large mononuclear cells scattered in portal tracts. Some of these cells showed a dendritic cell-like appearance. B7-2 positive cells were observed more frequently (41%) in PBC liver specimens than in chronic hepatitis C specimens (17%, P < 0.05). In PBC livers, such cells were preferentially observed around the damaged bile duct with a few located in the biliary epithelial layer. There was no such finding in chronic hepatitis C livers. The frequency and density of B7-2 positive cells in the liver specimens tended to decrease according to the stage of PBC (45% in stages 1 and 2, and 33% in stages 3 and 4; P = 0.10), whereas with chronic hepatitis C, no such tendency was observed. These findings suggest that B7-2 positive cells may play a role in the bile duct lesions that appear in the early histological stages of PBC and that the immunological mechanisms of bile duct damage, particularly of antigen presentation and B7-2 expression, differ between PBC and chronic hepatitis C.
authors.affiliation: Department of Pathology, Kanazawa University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kaji
authors.forename: K
authors.initials: K
authors.lastname: Tsuneyama
authors.forename: Y
authors.initials: Y
authors.lastname: Nakanuma
authors.forename: K
authors.initials: K
authors.lastname: Harada
authors.forename: M
authors.initials: M
authors.lastname: Sasaki
authors.forename: S
authors.initials: S
authors.lastname: Kaneko
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D051940:B7-2 Antigen; D001652:Bile Ducts / Q000378:metabolism*; D002908:Chronic Disease; D006526:Hepatitis C / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008099:Liver / Q000378:metabolism; D008105:Liver Cirrhosis, Biliary / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D051940:B7-2 Antigen; C497964:CD86 protein, human; D008562:Membrane Glycoproteins