Liver stellate cells in chronic viral hepatitis: the effect of interferon therapy.
OBJECTIVE
Liver stellate cell proliferation and differentiation into myofibroblast-like cells is related to the development of liver fibrosis. Several cytokines, including interferons, regulate liver stellate cell proliferation and phenotypic modulation. Recent studies indicate that human liver stellate cells express the alpha-isotype of actin, specific to smooth muscle cell differentiation. We aimed to evaluate the expression of alpha-smooth muscle actin-positive liver stellate cells in patients with chronic viral hepatitis and to evaluate whether and how such expression can be modified by alpha-interferon treatment.


METHODS
Using immunohistochemistry, and a semi-quantitative scoring method, we evaluated alpha-smooth muscle actin expression in liver stellate cells before and after alpha-interferon therapy in a series of liver biopsies from 44 patients with chronic viral hepatitis.


RESULTS
Before therapy, a large number of liver stellate cells expressing alpha-smooth muscle actin were present throughout all acinar zones. A significant reduction in alpha-smooth muscle actin expression by liver stellate cells was demonstrated in biopsies performed after suspending the interferon treatment. The drop in the number of alpha-smooth muscle actin-labelled cells after therapy correlated closely with the improvement in the histological index of activity.


CONCLUSIONS
The results suggest a specific effect of interferon on liver stellate cells, possibly related to its anti-inflammatory action.
Guido
M
M
Cattedra di Istochimica & Immunoistochimica Patologica, Istituto di Anatomia Patologica, Università degli Studi di Padova, Italy.
Rugge
M
M
Chemello
L
L
Leandro
G
G
Fattovich
G
G
Giustina
G
G
Cassaro
M
M
Alberti
A
A
D000199:Actins / Q000187:drug effects / Q000378:metabolism*; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D001706:Biopsy; D002455:Cell Division / Q000187:drug effects; D002908:Chronic Disease; D005260:Female; D006509:Hepatitis B / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006526:Hepatitis C / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D006801:Humans; D007150:Immunohistochemistry; D007370:Interferon Type I / Q000627:therapeutic use*; D008099:Liver / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009130:Muscle, Smooth / Q000378:metabolism; D011994:Recombinant Proteins; D016896:Treatment Outcome
D000199:Actins; D000998:Antiviral Agents; D007370:Interferon Type I; D011994:Recombinant Proteins