Interleukin-1-producing plasma cells in close contact with hepatocytes in patients with chronic active hepatitis.
OBJECTIVE
In chronic active liver diseases (CALD) with viral aetiology, a population of plasma cells localised in the piecemeal necrosis areas was previously detected by means of autoradiography after in vitro 3H-proline incorporation, a method which proved much more sensitive than conventional immunohistochemical procedures. These plasma cells, characteristically located in niches among hepatocytes, in close contact with collagen fibrils, have been hypothesised to exert a role in fibrogenesis stimulation, and particularly in collagen synthesis, possibly through secretion of lymphokines. Specifically, we investigated the presence of interleukin-1, well known to play a crucial role in inflammation and production of collagen by epithelial cells, and to be present in activated plasma cells of myeloma.


METHODS
The immunohistochemical localisation of interleukin-1beta in biopsies of patients suffering from chronic active hepatitis was studied, using an affinity-purified rabbit polyclonal antibody.


RESULTS
The strongest interleukin-1beta immunostaining was observed in the above-described plasma cell population, identified by anti-immunoglobulin antibodies, and 3H-proline incorporation.


CONCLUSIONS
The ability of plasma cells to produce interleukin-1 during viral CALD suggests that in these pathologies plasma cells play a major role, mainly of paracrine nature. Interleukin-1, possibly together with other mediators, might in turn stimulate the production of collagen. Hepatocytes of the piecemeal necrosis area appear to be possible candidates for this synthesis, as they show a significant labelling after 3H-proline incorporation, which is absent from hepatocytes far from necrotic areas.
Hassan
G
G
Centro Studi Malattie del Fegato, Ospedale S. Giacomo, Rome, Italy.
Moreno
S
S
Massimi
M
M
Di Biagio
P
P
Stefanini
S
S
D000328:Adult; D001345:Autoradiography; D001706:Biopsy; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D006509:Hepatitis B / Q000378:metabolism* / Q000473:pathology; D006526:Hepatitis C / Q000378:metabolism* / Q000473:pathology; D006521:Hepatitis, Chronic / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000378:metabolism*; D008099:Liver / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000378:metabolism / Q000473:pathology; D009336:Necrosis; D010950:Plasma Cells / Q000378:metabolism* / Q000648:ultrastructure
D007375:Interleukin-1