INTRAHEPATIC MAST-CELLS IN CHRONIC LIVER-DISEASES

Mast cells are known to be present in human liver but their distributi on and density in normal livers and in chronic liver diseases have not previously been examined, In this study, we quantified mast cell numb ers and examined their distribution in percutaneous biopsy specimens f rom normal livers (n = 8) and in two chronic progressive liver disease s: primary biliary cirrhosis (PBC) (n = 40) and alcoholic liver diseas e (n = 33). We compared differences in mast cell density between these two forms of chronic liver disease because it had been suggested that mast cells may play a role in the development of liver fibrosis, part icularly in patients with chronic cholestatic liver disease who freque ntly have increased plasma histamine levels, Mast cells were identifie d by immunohistochemistry using a specific monoclonal antibody (AA1) r aised against mast cell tryptase after an initial study showed this to be more sensitive for the detection of mast cells than the convention al histochemical stain, toluidine blue, Our results showed that small numbers of mast cells (3.9 +/- 3.3/mm(2)) are present within the porta l tracts and sinusoids of normal livers, In progressive chronic liver disease, increased numbers of mast cells were present, which correlate d with the increasing amounts of liver fibrosis present, We found sign ificantly more mast cells in the PBC group compared with the alcoholic group for a given amount of fibrosis, Our findings suggest that mast cells and their mediators may play a role in Liver fibrogenesis.