Hepatic stellate cells in biopsies from liver allografts with acute rejection.
BACKGROUND
[corrected] Hepatic stellate cells (HSCs) are nonparenchymal elements that play a major role in fibrogenesis due to various pathologies. HSCs are easily activated by certain injuries, which produce contraction and relaxation of HSCs, resulting in hepatic microcirculatory disturbances. The present study sought to analyze the expression of alpha-smooth muscle actin (alpha-SMA) positive HSCs in liver allografts during acute rejection episodes (ARE), determining whether it was related to the pathogenesis of this immune response.


METHODS
Using immunohistochemistry and a semiquantitative scoring system, the expression of alpha-SMA in HSCs was analyzed in liver allografts with ARE (group 1, n = 64) or without ARE (group 2, n = 20). Normal liver tissue from transplant donors (group 3, n = 53) served as the control materials.


RESULTS
Significantly more alpha-SMA positive HSCs were found in group 2 than in the other two groups (P < .05). The minimal difference observed between groups 1 and 3 was not statistically significant. As well, no statistical association was found between expression of alpha-SMA and the clinical parameters of age, gender, etiology of liver failure, donor type (partial or whole), posttransplantation period, and liver function tests.


CONCLUSIONS
While these results represent preliminary findings, it may be possible that HSC expression is a protective mechanism during ARE in hepatic allograft patients. If this is true, enhanced expression of this protein may mitigate ARE in liver allograft patients.
Department of Pathology, Başkent University, Faculty of Medicine, Ankara, Turkey. banubil@yahoo.com
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Bilezikçi
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Demirhan
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Sar
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Arat
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Karakayali
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Haberal
D000199:Actins / Q000032:analysis; D000208:Acute Disease; D000328:Adult; D001707:Biopsy, Needle; D016009:Chi-Square Distribution; D005260:Female; D006084:Graft Rejection / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000166:cytology / Q000473:pathology*; D008107:Liver Diseases / Q000145:classification / Q000601:surgery; D016031:Liver Transplantation / Q000473:pathology*; D008297:Male; D014019:Tissue Donors / Q000706:statistics & numerical data; D014184:Transplantation, Homologous / Q000473:pathology
D000199:Actins