Expression of alpha-smooth muscle actin in liver diseases.
To evaluate the distribution of alpha-smooth muscle actin (alpha-SMA) positive cells in various liver diseases, we undertook an immunohistochemical study of liver diseases including chronic persistent hepatitis, chronic active hepatitis, liver cirrhosis, intrahepatic cholelithiasis and hepatocellular carcinoma. As a control, fetal livers (gestational age: 22-26 weeks) showed alpha-SMA positive cells along the blood vessels of the portal area, terminal hepatic venules and at perisinusoidal spaces. Perisinusoidal alpha-SMA positive cells were bipolar shaped and had round nuclei. In chronic persistent hepatitis, a few alpha-SMA positive cells were admixed with the inflammatory infiltrates mostly along the intact limiting plate. They were also detected multifocally in a linear pattern along the dilated sinusoid. In chronic active hepatitis, very strong alpha-SMA staining was detected at the site of piecemeal necrosis and adjacent lobules. A-SMA expression was decreased in some cases after interferon treatment. In cases of transplanted liver biopsies, expression of intralobular alpha-SMA was diffusely increased but showed no correlation with degree of acute rejection. Cirrhotic livers revealed strong alpha-SMA positivity in fibrous septae as well as in the perisinusoidal space of intact hepatocytes at the leading edge of fibrosis. Interlobular bile ducts were concentrically circumscribed by alpha-SMA positive cells in cases of intrahepatic cholelithiasis. In trabecular type hepatocellular carcinomas, most sinusoidal lining cells were positive for alpha-SMA. Most intralobular alpha-SMA positive cells represent, if not all, perisinusoidal cells (PSCs) which are involved in intralobular fibrogenesis in various liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)
Yu
E
E
Department of Pathology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea.
Choe
G
G
Gong
G
G
Lee
I
I
D000199:Actins / Q000032:analysis*; D006528:Carcinoma, Hepatocellular / Q000737:chemistry; D005260:Female; D006505:Hepatitis / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000737:chemistry; D008103:Liver Cirrhosis / Q000378:metabolism; D008107:Liver Diseases / Q000378:metabolism*; D008113:Liver Neoplasms / Q000737:chemistry; D011247:Pregnancy
D000199:Actins