Primary biliary cirrhosis is a dry gland syndrome with features of chronic graft-versus-host disease

Abstract

Primary biliary cirrhosis (PBC) is part of a disease complex characterised by dry eyes, dry mouth, and both biliary and pancreatic hyposecretion: it is a "dry gland" syndrome resulting from damage to ductular epithelium. Additional extraglandular features include scleroderma-like skin lesions, pigmentation, Raynaud phenomenon and severe abnormalities of both humoral and cellular immunity. Identical ductular and extraductal features, including abnormalities of the immune system, are seen in chronic graft-versus-host disease after bone-marrow transplantation. It is suggested that in PBC the ductular lesions and severe disturbance of the immune system including macroglobulinaemia and immune complex formation occur as a result of an immune response to the histocompatibility (HC) complex antigens which are present in high density on ductular epithelial cells of the biliary tree. This response could be caused by altered antigenicity of epithelial cell HC antigens or by failure of the HLA-dependent T cell self-recognition system.